summaryrefslogblamecommitdiff
path: root/drivers/char/pcmcia/synclink_cs.c
blob: 73e3242099139e0c41892fe6198210355b2e413d (plain) (tree)
1
2
3
4
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881


                                          
                                                             
































                                                                      




















                            












                            




























































































































































                                                                                               
                                       


















































































































































































































































                                                                                       
                                                  










                                                                        
                                                     
                                       
                                                       
 












































                                                                       
                                                   

                      
            
 

                                        
 


                                                                   
                           



















                                                              
                       
                      
 
                                                       


                                              
                                        
                             
 
                              

                                           


                              


                            
             







                                                                             
                                                    
 




                                   











                                                               


                                                                   

                                               
 


                                              
                                                                  

                                 

                                                                   



















                                                                    
                                                                    


                                            






                                               
                                                               
 
                                                                                    






                                            
                                 








                                                            
             

          
                                      
                                 
                   







                                                      
                                                                 
 

                                                       
 
                                    

 
                                                     
 

                                                      
 

                                              
 
                                                        

 
                                                     
 

                                       
                       



                 
                                                    
 

                                       





                       


















































































































                                                                                       
                                     










































                                                                            
                                          










                                                                         
                                        







































































                                                                                              
                                         
                       
                     













                                                                              

                                                 





                                                                
                             
                                  

















                                                                      
                                                  
                                               
                                                 
                 
                                                              



                                             

                                               




                                                                             
                 










































































































































                                                                                                  





                                                            





































































                                                                                         
                                    





















































































































                                                                                    

                                                       






















































































































































































































                                                                                
                          

































































                                                                                         
                              













































































































































































































                                                                                






                                                                                          

























































































































































































































































































































































































































































                                                                                              
                                                                               


























































































































































































































































































































































































































































































































































































                                                                                        
                                              





















                                                                         
                                              
 
                            


                            
                                             








                                                                           
                                                










                                                                     
                                                


































                                                                    
                                                          






















                                                                       





                                                




                                             
                                       
                                        
                                     

                                         

  
                                                 







































                                                                                 

















































































































































































































                                                                                        
                                        














































































































































































































































                                                                           
                                      











                                                                
                                       














                                                                
                                       




































                                                                                  
                                      












                                                                     
                                           
















































                                                                             
                                         









































































































































































                                                                              
                                          









                                                                 
                                          




















                                                                    
                                          






















                                                            
                                               

















                                                                       
                                          




















































































                                                                                              
                                               


                                                         
                                                         









                                                                 
                                                            









                                                                          
                                          

































                                                        
                                          




















                                                                                                 
                                                                                

































                                                               
                                             


































































                                                                                    
                                            






































































































                                                                                 



                                                    














































































































































































































































































                                                                                                                
/*
 * linux/drivers/char/pcmcia/synclink_cs.c
 *
 * $Id: synclink_cs.c,v 4.34 2005/09/08 13:20:54 paulkf Exp $
 *
 * Device driver for Microgate SyncLink PC Card
 * multiprotocol serial adapter.
 *
 * written by Paul Fulghum for Microgate Corporation
 * paulkf@microgate.com
 *
 * Microgate and SyncLink are trademarks of Microgate Corporation
 *
 * This code is released under the GNU General Public License (GPL)
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#define VERSION(ver,rel,seq) (((ver)<<16) | ((rel)<<8) | (seq))
#if defined(__i386__)
#  define BREAKPOINT() asm("   int $3");
#else
#  define BREAKPOINT() { }
#endif

#define MAX_DEVICE_COUNT 4

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/ioctl.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/dma.h>
#include <linux/bitops.h>
#include <asm/types.h>
#include <linux/termios.h>
#include <linux/workqueue.h>
#include <linux/hdlc.h>

#include <pcmcia/cs_types.h>
#include <pcmcia/cs.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/cisreg.h>
#include <pcmcia/ds.h>

#ifdef CONFIG_HDLC_MODULE
#define CONFIG_HDLC 1
#endif

#define GET_USER(error,value,addr) error = get_user(value,addr)
#define COPY_FROM_USER(error,dest,src,size) error = copy_from_user(dest,src,size) ? -EFAULT : 0
#define PUT_USER(error,value,addr) error = put_user(value,addr)
#define COPY_TO_USER(error,dest,src,size) error = copy_to_user(dest,src,size) ? -EFAULT : 0

#include <asm/uaccess.h>

#include "linux/synclink.h"

static MGSL_PARAMS default_params = {
	MGSL_MODE_HDLC,			/* unsigned long mode */
	0,				/* unsigned char loopback; */
	HDLC_FLAG_UNDERRUN_ABORT15,	/* unsigned short flags; */
	HDLC_ENCODING_NRZI_SPACE,	/* unsigned char encoding; */
	0,				/* unsigned long clock_speed; */
	0xff,				/* unsigned char addr_filter; */
	HDLC_CRC_16_CCITT,		/* unsigned short crc_type; */
	HDLC_PREAMBLE_LENGTH_8BITS,	/* unsigned char preamble_length; */
	HDLC_PREAMBLE_PATTERN_NONE,	/* unsigned char preamble; */
	9600,				/* unsigned long data_rate; */
	8,				/* unsigned char data_bits; */
	1,				/* unsigned char stop_bits; */
	ASYNC_PARITY_NONE		/* unsigned char parity; */
};

typedef struct
{
	int count;
	unsigned char status;
	char data[1];
} RXBUF;

/* The queue of BH actions to be performed */

#define BH_RECEIVE  1
#define BH_TRANSMIT 2
#define BH_STATUS   4

#define IO_PIN_SHUTDOWN_LIMIT 100

#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

struct _input_signal_events {
	int	ri_up;	
	int	ri_down;
	int	dsr_up;
	int	dsr_down;
	int	dcd_up;
	int	dcd_down;
	int	cts_up;
	int	cts_down;
};


/*
 * Device instance data structure
 */
 
typedef struct _mgslpc_info {
	void *if_ptr;	/* General purpose pointer (used by SPPP) */
	int			magic;
	int			flags;
	int			count;		/* count of opens */
	int			line;
	unsigned short		close_delay;
	unsigned short		closing_wait;	/* time to wait before closing */
	
	struct mgsl_icount	icount;
	
	struct tty_struct 	*tty;
	int			timeout;
	int			x_char;		/* xon/xoff character */
	int			blocked_open;	/* # of blocked opens */
	unsigned char		read_status_mask;
	unsigned char		ignore_status_mask;	

	unsigned char *tx_buf;
	int            tx_put;
	int            tx_get;
	int            tx_count;

	/* circular list of fixed length rx buffers */

	unsigned char  *rx_buf;        /* memory allocated for all rx buffers */
	int            rx_buf_total_size; /* size of memory allocated for rx buffers */
	int            rx_put;         /* index of next empty rx buffer */
	int            rx_get;         /* index of next full rx buffer */
	int            rx_buf_size;    /* size in bytes of single rx buffer */
	int            rx_buf_count;   /* total number of rx buffers */
	int            rx_frame_count; /* number of full rx buffers */
	
	wait_queue_head_t	open_wait;
	wait_queue_head_t	close_wait;
	
	wait_queue_head_t	status_event_wait_q;
	wait_queue_head_t	event_wait_q;
	struct timer_list	tx_timer;	/* HDLC transmit timeout timer */
	struct _mgslpc_info	*next_device;	/* device list link */

	unsigned short imra_value;
	unsigned short imrb_value;
	unsigned char  pim_value;

	spinlock_t lock;
	struct work_struct task;		/* task structure for scheduling bh */

	u32 max_frame_size;

	u32 pending_bh;

	int bh_running;
	int bh_requested;
	
	int dcd_chkcount; /* check counts to prevent */
	int cts_chkcount; /* too many IRQs if a signal */
	int dsr_chkcount; /* is floating */
	int ri_chkcount;

	int rx_enabled;
	int rx_overflow;

	int tx_enabled;
	int tx_active;
	int tx_aborting;
	u32 idle_mode;

	int if_mode; /* serial interface selection (RS-232, v.35 etc) */

	char device_name[25];		/* device instance name */

	unsigned int io_base;	/* base I/O address of adapter */
	unsigned int irq_level;
	
	MGSL_PARAMS params;		/* communications parameters */

	unsigned char serial_signals;	/* current serial signal states */

	char irq_occurred;		/* for diagnostics use */
	char testing_irq;
	unsigned int init_error;	/* startup error (DIAGS)	*/

	char flag_buf[MAX_ASYNC_BUFFER_SIZE];
	BOOLEAN drop_rts_on_tx_done;

	struct	_input_signal_events	input_signal_events;

	/* PCMCIA support */
	struct pcmcia_device	*p_dev;
	dev_node_t	      node;
	int		      stop;

	/* SPPP/Cisco HDLC device parts */
	int netcount;
	int dosyncppp;
	spinlock_t netlock;

#ifdef CONFIG_HDLC
	struct net_device *netdev;
#endif

} MGSLPC_INFO;

#define MGSLPC_MAGIC 0x5402

/*
 * The size of the serial xmit buffer is 1 page, or 4096 bytes
 */
#define TXBUFSIZE 4096

    
#define CHA     0x00   /* channel A offset */
#define CHB     0x40   /* channel B offset */

/*
 *  FIXME: PPC has PVR defined in asm/reg.h.  For now we just undef it.
 */
#undef PVR

#define RXFIFO  0
#define TXFIFO  0
#define STAR    0x20
#define CMDR    0x20
#define RSTA    0x21
#define PRE     0x21
#define MODE    0x22
#define TIMR    0x23
#define XAD1    0x24
#define XAD2    0x25
#define RAH1    0x26
#define RAH2    0x27
#define DAFO    0x27
#define RAL1    0x28
#define RFC     0x28
#define RHCR    0x29
#define RAL2    0x29
#define RBCL    0x2a
#define XBCL    0x2a
#define RBCH    0x2b
#define XBCH    0x2b
#define CCR0    0x2c
#define CCR1    0x2d
#define CCR2    0x2e
#define CCR3    0x2f
#define VSTR    0x34
#define BGR     0x34
#define RLCR    0x35
#define AML     0x36
#define AMH     0x37
#define GIS     0x38
#define IVA     0x38
#define IPC     0x39
#define ISR     0x3a
#define IMR     0x3a
#define PVR     0x3c
#define PIS     0x3d
#define PIM     0x3d
#define PCR     0x3e
#define CCR4    0x3f
    
// IMR/ISR
    
#define IRQ_BREAK_ON    BIT15   // rx break detected
#define IRQ_DATAOVERRUN BIT14	// receive data overflow
#define IRQ_ALLSENT     BIT13	// all sent
#define IRQ_UNDERRUN    BIT12	// transmit data underrun
#define IRQ_TIMER       BIT11	// timer interrupt
#define IRQ_CTS         BIT10	// CTS status change
#define IRQ_TXREPEAT    BIT9	// tx message repeat
#define IRQ_TXFIFO      BIT8	// transmit pool ready
#define IRQ_RXEOM       BIT7	// receive message end
#define IRQ_EXITHUNT    BIT6	// receive frame start
#define IRQ_RXTIME      BIT6    // rx char timeout
#define IRQ_DCD         BIT2	// carrier detect status change
#define IRQ_OVERRUN     BIT1	// receive frame overflow
#define IRQ_RXFIFO      BIT0	// receive pool full
    
// STAR
    
#define XFW   BIT6		// transmit FIFO write enable
#define CEC   BIT2		// command executing
#define CTS   BIT1		// CTS state
    
#define PVR_DTR      BIT0
#define PVR_DSR      BIT1
#define PVR_RI       BIT2
#define PVR_AUTOCTS  BIT3
#define PVR_RS232    0x20   /* 0010b */
#define PVR_V35      0xe0   /* 1110b */
#define PVR_RS422    0x40   /* 0100b */
    
/* Register access functions */ 
    
#define write_reg(info, reg, val) outb((val),(info)->io_base + (reg))
#define read_reg(info, reg) inb((info)->io_base + (reg))

#define read_reg16(info, reg) inw((info)->io_base + (reg))  
#define write_reg16(info, reg, val) outw((val), (info)->io_base + (reg))
    
#define set_reg_bits(info, reg, mask) \
    write_reg(info, (reg), \
		 (unsigned char) (read_reg(info, (reg)) | (mask)))  
#define clear_reg_bits(info, reg, mask) \
    write_reg(info, (reg), \
		 (unsigned char) (read_reg(info, (reg)) & ~(mask)))  
/*
 * interrupt enable/disable routines
 */ 
static void irq_disable(MGSLPC_INFO *info, unsigned char channel, unsigned short mask) 
{
	if (channel == CHA) {
		info->imra_value |= mask;
		write_reg16(info, CHA + IMR, info->imra_value);
	} else {
		info->imrb_value |= mask;
		write_reg16(info, CHB + IMR, info->imrb_value);
	}
}
static void irq_enable(MGSLPC_INFO *info, unsigned char channel, unsigned short mask) 
{
	if (channel == CHA) {
		info->imra_value &= ~mask;
		write_reg16(info, CHA + IMR, info->imra_value);
	} else {
		info->imrb_value &= ~mask;
		write_reg16(info, CHB + IMR, info->imrb_value);
	}
}

#define port_irq_disable(info, mask) \
  { info->pim_value |= (mask); write_reg(info, PIM, info->pim_value); }

#define port_irq_enable(info, mask) \
  { info->pim_value &= ~(mask); write_reg(info, PIM, info->pim_value); }

static void rx_start(MGSLPC_INFO *info);
static void rx_stop(MGSLPC_INFO *info);

static void tx_start(MGSLPC_INFO *info);
static void tx_stop(MGSLPC_INFO *info);
static void tx_set_idle(MGSLPC_INFO *info);

static void get_signals(MGSLPC_INFO *info);
static void set_signals(MGSLPC_INFO *info);

static void reset_device(MGSLPC_INFO *info);

static void hdlc_mode(MGSLPC_INFO *info);
static void async_mode(MGSLPC_INFO *info);

static void tx_timeout(unsigned long context);

static int ioctl_common(MGSLPC_INFO *info, unsigned int cmd, unsigned long arg);

#ifdef CONFIG_HDLC
#define dev_to_port(D) (dev_to_hdlc(D)->priv)
static void hdlcdev_tx_done(MGSLPC_INFO *info);
static void hdlcdev_rx(MGSLPC_INFO *info, char *buf, int size);
static int  hdlcdev_init(MGSLPC_INFO *info);
static void hdlcdev_exit(MGSLPC_INFO *info);
#endif

static void trace_block(MGSLPC_INFO *info,const char* data, int count, int xmit);

static BOOLEAN register_test(MGSLPC_INFO *info);
static BOOLEAN irq_test(MGSLPC_INFO *info);
static int adapter_test(MGSLPC_INFO *info);

static int claim_resources(MGSLPC_INFO *info);
static void release_resources(MGSLPC_INFO *info);
static void mgslpc_add_device(MGSLPC_INFO *info);
static void mgslpc_remove_device(MGSLPC_INFO *info);

static int  rx_get_frame(MGSLPC_INFO *info);
static void rx_reset_buffers(MGSLPC_INFO *info);
static int  rx_alloc_buffers(MGSLPC_INFO *info);
static void rx_free_buffers(MGSLPC_INFO *info);

static irqreturn_t mgslpc_isr(int irq, void *dev_id, struct pt_regs * regs);

/*
 * Bottom half interrupt handlers
 */
static void bh_handler(void* Context);
static void bh_transmit(MGSLPC_INFO *info);
static void bh_status(MGSLPC_INFO *info);

/*
 * ioctl handlers
 */
static int tiocmget(struct tty_struct *tty, struct file *file);
static int tiocmset(struct tty_struct *tty, struct file *file,
		    unsigned int set, unsigned int clear);
static int get_stats(MGSLPC_INFO *info, struct mgsl_icount __user *user_icount);
static int get_params(MGSLPC_INFO *info, MGSL_PARAMS __user *user_params);
static int set_params(MGSLPC_INFO *info, MGSL_PARAMS __user *new_params);
static int get_txidle(MGSLPC_INFO *info, int __user *idle_mode);
static int set_txidle(MGSLPC_INFO *info, int idle_mode);
static int set_txenable(MGSLPC_INFO *info, int enable);
static int tx_abort(MGSLPC_INFO *info);
static int set_rxenable(MGSLPC_INFO *info, int enable);
static int wait_events(MGSLPC_INFO *info, int __user *mask);

static MGSLPC_INFO *mgslpc_device_list = NULL;
static int mgslpc_device_count = 0;

/*
 * Set this param to non-zero to load eax with the
 * .text section address and breakpoint on module load.
 * This is useful for use with gdb and add-symbol-file command.
 */
static int break_on_load=0;

/*
 * Driver major number, defaults to zero to get auto
 * assigned major number. May be forced as module parameter.
 */
static int ttymajor=0;

static int debug_level = 0;
static int maxframe[MAX_DEVICE_COUNT] = {0,};
static int dosyncppp[MAX_DEVICE_COUNT] = {1,1,1,1};

module_param(break_on_load, bool, 0);
module_param(ttymajor, int, 0);
module_param(debug_level, int, 0);
module_param_array(maxframe, int, NULL, 0);
module_param_array(dosyncppp, int, NULL, 0);

MODULE_LICENSE("GPL");

static char *driver_name = "SyncLink PC Card driver";
static char *driver_version = "$Revision: 4.34 $";

static struct tty_driver *serial_driver;

/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256

static void mgslpc_change_params(MGSLPC_INFO *info);
static void mgslpc_wait_until_sent(struct tty_struct *tty, int timeout);

/* PCMCIA prototypes */

static int mgslpc_config(struct pcmcia_device *link);
static void mgslpc_release(u_long arg);
static void mgslpc_detach(struct pcmcia_device *p_dev);

/*
 * 1st function defined in .text section. Calling this function in
 * init_module() followed by a breakpoint allows a remote debugger
 * (gdb) to get the .text address for the add-symbol-file command.
 * This allows remote debugging of dynamically loadable modules.
 */
static void* mgslpc_get_text_ptr(void)
{
	return mgslpc_get_text_ptr;
}

/**
 * line discipline callback wrappers
 *
 * The wrappers maintain line discipline references
 * while calling into the line discipline.
 *
 * ldisc_flush_buffer - flush line discipline receive buffers
 * ldisc_receive_buf  - pass receive data to line discipline
 */

static void ldisc_flush_buffer(struct tty_struct *tty)
{
	struct tty_ldisc *ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->flush_buffer)
			ld->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
}

static void ldisc_receive_buf(struct tty_struct *tty,
			      const __u8 *data, char *flags, int count)
{
	struct tty_ldisc *ld;
	if (!tty)
		return;
	ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->receive_buf)
			ld->receive_buf(tty, data, flags, count);
		tty_ldisc_deref(ld);
	}
}

static int mgslpc_probe(struct pcmcia_device *link)
{
    MGSLPC_INFO *info;
    int ret;

    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_attach\n");

    info = (MGSLPC_INFO *)kmalloc(sizeof(MGSLPC_INFO), GFP_KERNEL);
    if (!info) {
	    printk("Error can't allocate device instance data\n");
	    return -ENOMEM;
    }

    memset(info, 0, sizeof(MGSLPC_INFO));
    info->magic = MGSLPC_MAGIC;
    INIT_WORK(&info->task, bh_handler, info);
    info->max_frame_size = 4096;
    info->close_delay = 5*HZ/10;
    info->closing_wait = 30*HZ;
    init_waitqueue_head(&info->open_wait);
    init_waitqueue_head(&info->close_wait);
    init_waitqueue_head(&info->status_event_wait_q);
    init_waitqueue_head(&info->event_wait_q);
    spin_lock_init(&info->lock);
    spin_lock_init(&info->netlock);
    memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
    info->idle_mode = HDLC_TXIDLE_FLAGS;		
    info->imra_value = 0xffff;
    info->imrb_value = 0xffff;
    info->pim_value = 0xff;

    info->p_dev = link;
    link->priv = info;

    /* Initialize the struct pcmcia_device structure */

    /* Interrupt setup */
    link->irq.Attributes = IRQ_TYPE_EXCLUSIVE;
    link->irq.IRQInfo1   = IRQ_LEVEL_ID;
    link->irq.Handler = NULL;

    link->conf.Attributes = 0;
    link->conf.IntType = INT_MEMORY_AND_IO;

    ret = mgslpc_config(link);
    if (ret)
	    return ret;

    mgslpc_add_device(info);

    return 0;
}

/* Card has been inserted.
 */

#define CS_CHECK(fn, ret) \
do { last_fn = (fn); if ((last_ret = (ret)) != 0) goto cs_failed; } while (0)

static int mgslpc_config(struct pcmcia_device *link)
{
    MGSLPC_INFO *info = link->priv;
    tuple_t tuple;
    cisparse_t parse;
    int last_fn, last_ret;
    u_char buf[64];
    cistpl_cftable_entry_t dflt = { 0 };
    cistpl_cftable_entry_t *cfg;
    
    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_config(0x%p)\n", link);

    /* read CONFIG tuple to find its configuration registers */
    tuple.DesiredTuple = CISTPL_CONFIG;
    tuple.Attributes = 0;
    tuple.TupleData = buf;
    tuple.TupleDataMax = sizeof(buf);
    tuple.TupleOffset = 0;
    CS_CHECK(GetFirstTuple, pcmcia_get_first_tuple(link, &tuple));
    CS_CHECK(GetTupleData, pcmcia_get_tuple_data(link, &tuple));
    CS_CHECK(ParseTuple, pcmcia_parse_tuple(link, &tuple, &parse));
    link->conf.ConfigBase = parse.config.base;
    link->conf.Present = parse.config.rmask[0];

    /* get CIS configuration entry */

    tuple.DesiredTuple = CISTPL_CFTABLE_ENTRY;
    CS_CHECK(GetFirstTuple, pcmcia_get_first_tuple(link, &tuple));

    cfg = &(parse.cftable_entry);
    CS_CHECK(GetTupleData, pcmcia_get_tuple_data(link, &tuple));
    CS_CHECK(ParseTuple, pcmcia_parse_tuple(link, &tuple, &parse));

    if (cfg->flags & CISTPL_CFTABLE_DEFAULT) dflt = *cfg;
    if (cfg->index == 0)
	    goto cs_failed;

    link->conf.ConfigIndex = cfg->index;
    link->conf.Attributes |= CONF_ENABLE_IRQ;
	
    /* IO window settings */
    link->io.NumPorts1 = 0;
    if ((cfg->io.nwin > 0) || (dflt.io.nwin > 0)) {
	    cistpl_io_t *io = (cfg->io.nwin) ? &cfg->io : &dflt.io;
	    link->io.Attributes1 = IO_DATA_PATH_WIDTH_AUTO;
	    if (!(io->flags & CISTPL_IO_8BIT))
		    link->io.Attributes1 = IO_DATA_PATH_WIDTH_16;
	    if (!(io->flags & CISTPL_IO_16BIT))
		    link->io.Attributes1 = IO_DATA_PATH_WIDTH_8;
	    link->io.IOAddrLines = io->flags & CISTPL_IO_LINES_MASK;
	    link->io.BasePort1 = io->win[0].base;
	    link->io.NumPorts1 = io->win[0].len;
	    CS_CHECK(RequestIO, pcmcia_request_io(link, &link->io));
    }

    link->conf.Attributes = CONF_ENABLE_IRQ;
    link->conf.IntType = INT_MEMORY_AND_IO;
    link->conf.ConfigIndex = 8;
    link->conf.Present = PRESENT_OPTION;
    
    link->irq.Attributes |= IRQ_HANDLE_PRESENT;
    link->irq.Handler     = mgslpc_isr;
    link->irq.Instance    = info;
    CS_CHECK(RequestIRQ, pcmcia_request_irq(link, &link->irq));

    CS_CHECK(RequestConfiguration, pcmcia_request_configuration(link, &link->conf));

    info->io_base = link->io.BasePort1;
    info->irq_level = link->irq.AssignedIRQ;

    /* add to linked list of devices */
    sprintf(info->node.dev_name, "mgslpc0");
    info->node.major = info->node.minor = 0;
    link->dev_node = &info->node;

    printk(KERN_INFO "%s: index 0x%02x:",
	   info->node.dev_name, link->conf.ConfigIndex);
    if (link->conf.Attributes & CONF_ENABLE_IRQ)
	    printk(", irq %d", link->irq.AssignedIRQ);
    if (link->io.NumPorts1)
	    printk(", io 0x%04x-0x%04x", link->io.BasePort1,
		   link->io.BasePort1+link->io.NumPorts1-1);
    printk("\n");
    return 0;

cs_failed:
    cs_error(link, last_fn, last_ret);
    mgslpc_release((u_long)link);
    return -ENODEV;
}

/* Card has been removed.
 * Unregister device and release PCMCIA configuration.
 * If device is open, postpone until it is closed.
 */
static void mgslpc_release(u_long arg)
{
	struct pcmcia_device *link = (struct pcmcia_device *)arg;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("mgslpc_release(0x%p)\n", link);

	pcmcia_disable_device(link);
}

static void mgslpc_detach(struct pcmcia_device *link)
{
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("mgslpc_detach(0x%p)\n", link);

	((MGSLPC_INFO *)link->priv)->stop = 1;
	mgslpc_release((u_long)link);

	mgslpc_remove_device((MGSLPC_INFO *)link->priv);
}

static int mgslpc_suspend(struct pcmcia_device *link)
{
	MGSLPC_INFO *info = link->priv;

	info->stop = 1;

	return 0;
}

static int mgslpc_resume(struct pcmcia_device *link)
{
	MGSLPC_INFO *info = link->priv;

	info->stop = 0;

	return 0;
}


static inline int mgslpc_paranoia_check(MGSLPC_INFO *info,
					char *name, const char *routine)
{
#ifdef MGSLPC_PARANOIA_CHECK
	static const char *badmagic =
		"Warning: bad magic number for mgsl struct (%s) in %s\n";
	static const char *badinfo =
		"Warning: null mgslpc_info for (%s) in %s\n";

	if (!info) {
		printk(badinfo, name, routine);
		return 1;
	}
	if (info->magic != MGSLPC_MAGIC) {
		printk(badmagic, name, routine);
		return 1;
	}
#else
	if (!info)
		return 1;
#endif
	return 0;
}


#define CMD_RXFIFO      BIT7	// release current rx FIFO
#define CMD_RXRESET     BIT6	// receiver reset
#define CMD_RXFIFO_READ BIT5
#define CMD_START_TIMER BIT4
#define CMD_TXFIFO      BIT3	// release current tx FIFO
#define CMD_TXEOM       BIT1	// transmit end message
#define CMD_TXRESET     BIT0	// transmit reset

static BOOLEAN wait_command_complete(MGSLPC_INFO *info, unsigned char channel) 
{
	int i = 0;
	/* wait for command completion */ 
	while (read_reg(info, (unsigned char)(channel+STAR)) & BIT2) {
		udelay(1);
		if (i++ == 1000)
			return FALSE;
	}
	return TRUE;
}

static void issue_command(MGSLPC_INFO *info, unsigned char channel, unsigned char cmd) 
{
	wait_command_complete(info, channel);
	write_reg(info, (unsigned char) (channel + CMDR), cmd);
}

static void tx_pause(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (mgslpc_paranoia_check(info, tty->name, "tx_pause"))
		return;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_pause(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->lock,flags);
	if (info->tx_enabled)
	 	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

static void tx_release(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (mgslpc_paranoia_check(info, tty->name, "tx_release"))
		return;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_release(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_enabled)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Return next bottom half action to perform.
 * or 0 if nothing to do.
 */
static int bh_action(MGSLPC_INFO *info)
{
	unsigned long flags;
	int rc = 0;
	
	spin_lock_irqsave(&info->lock,flags);

	if (info->pending_bh & BH_RECEIVE) {
		info->pending_bh &= ~BH_RECEIVE;
		rc = BH_RECEIVE;
	} else if (info->pending_bh & BH_TRANSMIT) {
		info->pending_bh &= ~BH_TRANSMIT;
		rc = BH_TRANSMIT;
	} else if (info->pending_bh & BH_STATUS) {
		info->pending_bh &= ~BH_STATUS;
		rc = BH_STATUS;
	}

	if (!rc) {
		/* Mark BH routine as complete */
		info->bh_running   = 0;
		info->bh_requested = 0;
	}
	
	spin_unlock_irqrestore(&info->lock,flags);
	
	return rc;
}

static void bh_handler(void* Context)
{
	MGSLPC_INFO *info = (MGSLPC_INFO*)Context;
	int action;

	if (!info)
		return;
		
	if (debug_level >= DEBUG_LEVEL_BH)
		printk( "%s(%d):bh_handler(%s) entry\n",
			__FILE__,__LINE__,info->device_name);
	
	info->bh_running = 1;

	while((action = bh_action(info)) != 0) {
	
		/* Process work item */
		if ( debug_level >= DEBUG_LEVEL_BH )
			printk( "%s(%d):bh_handler() work item action=%d\n",
				__FILE__,__LINE__,action);

		switch (action) {
		
		case BH_RECEIVE:
			while(rx_get_frame(info));
			break;
		case BH_TRANSMIT:
			bh_transmit(info);
			break;
		case BH_STATUS:
			bh_status(info);
			break;
		default:
			/* unknown work item ID */
			printk("Unknown work item ID=%08X!\n", action);
			break;
		}
	}

	if (debug_level >= DEBUG_LEVEL_BH)
		printk( "%s(%d):bh_handler(%s) exit\n",
			__FILE__,__LINE__,info->device_name);
}

static void bh_transmit(MGSLPC_INFO *info)
{
	struct tty_struct *tty = info->tty;
	if (debug_level >= DEBUG_LEVEL_BH)
		printk("bh_transmit() entry on %s\n", info->device_name);

	if (tty) {
		tty_wakeup(tty);
		wake_up_interruptible(&tty->write_wait);
	}
}

static void bh_status(MGSLPC_INFO *info)
{
	info->ri_chkcount = 0;
	info->dsr_chkcount = 0;
	info->dcd_chkcount = 0;
	info->cts_chkcount = 0;
}

/* eom: non-zero = end of frame */ 
static void rx_ready_hdlc(MGSLPC_INFO *info, int eom)
{
	unsigned char data[2];
	unsigned char fifo_count, read_count, i;
	RXBUF *buf = (RXBUF*)(info->rx_buf + (info->rx_put * info->rx_buf_size));

	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):rx_ready_hdlc(eom=%d)\n",__FILE__,__LINE__,eom);
	
	if (!info->rx_enabled)
		return;

	if (info->rx_frame_count >= info->rx_buf_count) {
		/* no more free buffers */
		issue_command(info, CHA, CMD_RXRESET);
		info->pending_bh |= BH_RECEIVE;
		info->rx_overflow = 1;
		info->icount.buf_overrun++;
		return;
	}

	if (eom) {
		/* end of frame, get FIFO count from RBCL register */ 
		if (!(fifo_count = (unsigned char)(read_reg(info, CHA+RBCL) & 0x1f)))
			fifo_count = 32;
	} else
		fifo_count = 32;
	
	do {
		if (fifo_count == 1) {
			read_count = 1;
			data[0] = read_reg(info, CHA + RXFIFO);
		} else {
			read_count = 2;
			*((unsigned short *) data) = read_reg16(info, CHA + RXFIFO);
		}
		fifo_count -= read_count;
		if (!fifo_count && eom)
			buf->status = data[--read_count];

		for (i = 0; i < read_count; i++) {
			if (buf->count >= info->max_frame_size) {
				/* frame too large, reset receiver and reset current buffer */
				issue_command(info, CHA, CMD_RXRESET);
				buf->count = 0;
				return;
			}
			*(buf->data + buf->count) = data[i];
			buf->count++;
		}
	} while (fifo_count);

	if (eom) {
		info->pending_bh |= BH_RECEIVE;
		info->rx_frame_count++;
		info->rx_put++;
		if (info->rx_put >= info->rx_buf_count)
			info->rx_put = 0;
	}
	issue_command(info, CHA, CMD_RXFIFO);
}

static void rx_ready_async(MGSLPC_INFO *info, int tcd)
{
	unsigned char data, status, flag;
	int fifo_count;
	int work = 0;
 	struct tty_struct *tty = info->tty;
 	struct mgsl_icount *icount = &info->icount;

	if (tcd) {
		/* early termination, get FIFO count from RBCL register */ 
		fifo_count = (unsigned char)(read_reg(info, CHA+RBCL) & 0x1f);

		/* Zero fifo count could mean 0 or 32 bytes available.
		 * If BIT5 of STAR is set then at least 1 byte is available.
		 */
		if (!fifo_count && (read_reg(info,CHA+STAR) & BIT5))
			fifo_count = 32;
	} else
		fifo_count = 32;

	tty_buffer_request_room(tty, fifo_count);
	/* Flush received async data to receive data buffer. */ 
	while (fifo_count) {
		data   = read_reg(info, CHA + RXFIFO);
		status = read_reg(info, CHA + RXFIFO);
		fifo_count -= 2;

		icount->rx++;
		flag = TTY_NORMAL;

		// if no frameing/crc error then save data
		// BIT7:parity error
		// BIT6:framing error

		if (status & (BIT7 + BIT6)) {
			if (status & BIT7) 
				icount->parity++;
			else
				icount->frame++;

			/* discard char if tty control flags say so */
			if (status & info->ignore_status_mask)
				continue;
				
			status &= info->read_status_mask;

			if (status & BIT7)
				flag = TTY_PARITY;
			else if (status & BIT6)
				flag = TTY_FRAME;
		}
		work += tty_insert_flip_char(tty, data, flag);
	}
	issue_command(info, CHA, CMD_RXFIFO);

	if (debug_level >= DEBUG_LEVEL_ISR) {
		printk("%s(%d):rx_ready_async",
			__FILE__,__LINE__);
		printk("%s(%d):rx=%d brk=%d parity=%d frame=%d overrun=%d\n",
			__FILE__,__LINE__,icount->rx,icount->brk,
			icount->parity,icount->frame,icount->overrun);
	}
			
	if (work)
		tty_flip_buffer_push(tty);
}


static void tx_done(MGSLPC_INFO *info)
{
	if (!info->tx_active)
		return;
			
	info->tx_active = 0;
	info->tx_aborting = 0;

	if (info->params.mode == MGSL_MODE_ASYNC)
		return;

	info->tx_count = info->tx_put = info->tx_get = 0;
	del_timer(&info->tx_timer);	
	
	if (info->drop_rts_on_tx_done) {
		get_signals(info);
		if (info->serial_signals & SerialSignal_RTS) {
			info->serial_signals &= ~SerialSignal_RTS;
			set_signals(info);
		}
		info->drop_rts_on_tx_done = 0;
	}

#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlcdev_tx_done(info);
	else 
#endif
	{
		if (info->tty->stopped || info->tty->hw_stopped) {
			tx_stop(info);
			return;
		}
		info->pending_bh |= BH_TRANSMIT;
	}
}

static void tx_ready(MGSLPC_INFO *info)
{
	unsigned char fifo_count = 32;
	int c;

	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):tx_ready(%s)\n", __FILE__,__LINE__,info->device_name);

	if (info->params.mode == MGSL_MODE_HDLC) {
		if (!info->tx_active)
			return;
	} else {
		if (info->tty->stopped || info->tty->hw_stopped) {
			tx_stop(info);
			return;
		}
		if (!info->tx_count)
			info->tx_active = 0;
	}

	if (!info->tx_count)
		return;

	while (info->tx_count && fifo_count) {
		c = min(2, min_t(int, fifo_count, min(info->tx_count, TXBUFSIZE - info->tx_get)));
		
		if (c == 1) {
			write_reg(info, CHA + TXFIFO, *(info->tx_buf + info->tx_get));
		} else {
			write_reg16(info, CHA + TXFIFO,
					  *((unsigned short*)(info->tx_buf + info->tx_get)));
		}
		info->tx_count -= c;
		info->tx_get = (info->tx_get + c) & (TXBUFSIZE - 1);
		fifo_count -= c;
	}

	if (info->params.mode == MGSL_MODE_ASYNC) {
		if (info->tx_count < WAKEUP_CHARS)
			info->pending_bh |= BH_TRANSMIT;
		issue_command(info, CHA, CMD_TXFIFO);
	} else {
		if (info->tx_count)
			issue_command(info, CHA, CMD_TXFIFO);
		else
			issue_command(info, CHA, CMD_TXFIFO + CMD_TXEOM);
	}
}

static void cts_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->cts_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		irq_disable(info, CHB, IRQ_CTS);
	info->icount.cts++;
	if (info->serial_signals & SerialSignal_CTS)
		info->input_signal_events.cts_up++;
	else
		info->input_signal_events.cts_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	if (info->flags & ASYNC_CTS_FLOW) {
		if (info->tty->hw_stopped) {
			if (info->serial_signals & SerialSignal_CTS) {
				if (debug_level >= DEBUG_LEVEL_ISR)
					printk("CTS tx start...");
				if (info->tty)
					info->tty->hw_stopped = 0;
				tx_start(info);
				info->pending_bh |= BH_TRANSMIT;
				return;
			}
		} else {
			if (!(info->serial_signals & SerialSignal_CTS)) {
				if (debug_level >= DEBUG_LEVEL_ISR)
					printk("CTS tx stop...");
				if (info->tty)
					info->tty->hw_stopped = 1;
				tx_stop(info);
			}
		}
	}
	info->pending_bh |= BH_STATUS;
}

static void dcd_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->dcd_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		irq_disable(info, CHB, IRQ_DCD);
	info->icount.dcd++;
	if (info->serial_signals & SerialSignal_DCD) {
		info->input_signal_events.dcd_up++;
	}
	else
		info->input_signal_events.dcd_down++;
#ifdef CONFIG_HDLC
	if (info->netcount) {
		if (info->serial_signals & SerialSignal_DCD)
			netif_carrier_on(info->netdev);
		else
			netif_carrier_off(info->netdev);
	}
#endif
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	if (info->flags & ASYNC_CHECK_CD) {
		if (debug_level >= DEBUG_LEVEL_ISR)
			printk("%s CD now %s...", info->device_name,
			       (info->serial_signals & SerialSignal_DCD) ? "on" : "off");
		if (info->serial_signals & SerialSignal_DCD)
			wake_up_interruptible(&info->open_wait);
		else {
			if (debug_level >= DEBUG_LEVEL_ISR)
				printk("doing serial hangup...");
			if (info->tty)
				tty_hangup(info->tty);
		}
	}
	info->pending_bh |= BH_STATUS;
}

static void dsr_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->dsr_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		port_irq_disable(info, PVR_DSR);
	info->icount.dsr++;
	if (info->serial_signals & SerialSignal_DSR)
		info->input_signal_events.dsr_up++;
	else
		info->input_signal_events.dsr_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

static void ri_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->ri_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		port_irq_disable(info, PVR_RI);
	info->icount.rng++;
	if (info->serial_signals & SerialSignal_RI)
		info->input_signal_events.ri_up++;
	else
		info->input_signal_events.ri_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

/* Interrupt service routine entry point.
 * 	
 * Arguments:
 * 
 * irq     interrupt number that caused interrupt
 * dev_id  device ID supplied during interrupt registration
 * regs    interrupted processor context
 */
static irqreturn_t mgslpc_isr(int irq, void *dev_id, struct pt_regs * regs)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)dev_id;
	unsigned short isr;
	unsigned char gis, pis;
	int count=0;

	if (debug_level >= DEBUG_LEVEL_ISR)	
		printk("mgslpc_isr(%d) entry.\n", irq);
	if (!info)
		return IRQ_NONE;
		
	if (!(info->p_dev->_locked))
		return IRQ_HANDLED;

	spin_lock(&info->lock);

	while ((gis = read_reg(info, CHA + GIS))) {
		if (debug_level >= DEBUG_LEVEL_ISR)	
			printk("mgslpc_isr %s gis=%04X\n", info->device_name,gis);

		if ((gis & 0x70) || count > 1000) {
			printk("synclink_cs:hardware failed or ejected\n");
			break;
		}
		count++;

		if (gis & (BIT1 + BIT0)) {
			isr = read_reg16(info, CHB + ISR);
			if (isr & IRQ_DCD)
				dcd_change(info);
			if (isr & IRQ_CTS)
				cts_change(info);
		}
		if (gis & (BIT3 + BIT2))
		{
			isr = read_reg16(info, CHA + ISR);
			if (isr & IRQ_TIMER) {
				info->irq_occurred = 1;
				irq_disable(info, CHA, IRQ_TIMER);
			}

			/* receive IRQs */ 
			if (isr & IRQ_EXITHUNT) {
				info->icount.exithunt++;
				wake_up_interruptible(&info->event_wait_q);
			}
			if (isr & IRQ_BREAK_ON) {
				info->icount.brk++;
				if (info->flags & ASYNC_SAK)
					do_SAK(info->tty);
			}
			if (isr & IRQ_RXTIME) {
				issue_command(info, CHA, CMD_RXFIFO_READ);
			}
			if (isr & (IRQ_RXEOM + IRQ_RXFIFO)) {
				if (info->params.mode == MGSL_MODE_HDLC)
					rx_ready_hdlc(info, isr & IRQ_RXEOM); 
				else
					rx_ready_async(info, isr & IRQ_RXEOM);
			}

			/* transmit IRQs */ 
			if (isr & IRQ_UNDERRUN) {
				if (info->tx_aborting)
					info->icount.txabort++;
				else
					info->icount.txunder++;
				tx_done(info);
			}
			else if (isr & IRQ_ALLSENT) {
				info->icount.txok++;
				tx_done(info);
			}
			else if (isr & IRQ_TXFIFO)
				tx_ready(info);
		}
		if (gis & BIT7) {
			pis = read_reg(info, CHA + PIS);
			if (pis & BIT1)
				dsr_change(info);
			if (pis & BIT2)
				ri_change(info);
		}
	}
	
	/* Request bottom half processing if there's something 
	 * for it to do and the bh is not already running
	 */

	if (info->pending_bh && !info->bh_running && !info->bh_requested) {
		if ( debug_level >= DEBUG_LEVEL_ISR )	
			printk("%s(%d):%s queueing bh task.\n",
				__FILE__,__LINE__,info->device_name);
		schedule_work(&info->task);
		info->bh_requested = 1;
	}

	spin_unlock(&info->lock);
	
	if (debug_level >= DEBUG_LEVEL_ISR)	
		printk("%s(%d):mgslpc_isr(%d)exit.\n",
		       __FILE__,__LINE__,irq);

	return IRQ_HANDLED;
}

/* Initialize and start device.
 */
static int startup(MGSLPC_INFO * info)
{
	int retval = 0;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):startup(%s)\n",__FILE__,__LINE__,info->device_name);
		
	if (info->flags & ASYNC_INITIALIZED)
		return 0;
	
	if (!info->tx_buf) {
		/* allocate a page of memory for a transmit buffer */
		info->tx_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
		if (!info->tx_buf) {
			printk(KERN_ERR"%s(%d):%s can't allocate transmit buffer\n",
				__FILE__,__LINE__,info->device_name);
			return -ENOMEM;
		}
	}

	info->pending_bh = 0;
	
	memset(&info->icount, 0, sizeof(info->icount));

	init_timer(&info->tx_timer);
	info->tx_timer.data = (unsigned long)info;
	info->tx_timer.function = tx_timeout;

	/* Allocate and claim adapter resources */
	retval = claim_resources(info);
	
	/* perform existance check and diagnostics */
	if ( !retval )
		retval = adapter_test(info);
		
	if ( retval ) {
  		if (capable(CAP_SYS_ADMIN) && info->tty)
			set_bit(TTY_IO_ERROR, &info->tty->flags);
		release_resources(info);
  		return retval;
  	}

	/* program hardware for current parameters */
	mgslpc_change_params(info);
	
	if (info->tty)
		clear_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags |= ASYNC_INITIALIZED;
	
	return 0;
}

/* Called by mgslpc_close() and mgslpc_hangup() to shutdown hardware
 */
static void shutdown(MGSLPC_INFO * info)
{
	unsigned long flags;
	
	if (!(info->flags & ASYNC_INITIALIZED))
		return;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_shutdown(%s)\n",
			 __FILE__,__LINE__, info->device_name );

	/* clear status wait queue because status changes */
	/* can't happen after shutting down the hardware */
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	del_timer(&info->tx_timer);	

	if (info->tx_buf) {
		free_page((unsigned long) info->tx_buf);
		info->tx_buf = NULL;
	}

	spin_lock_irqsave(&info->lock,flags);

	rx_stop(info);
	tx_stop(info);

	/* TODO:disable interrupts instead of reset to preserve signal states */
	reset_device(info);
	
 	if (!info->tty || info->tty->termios->c_cflag & HUPCL) {
 		info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
		set_signals(info);
	}
	
	spin_unlock_irqrestore(&info->lock,flags);

	release_resources(info);	
	
	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;
}

static void mgslpc_program_hw(MGSLPC_INFO *info)
{
	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
	
	rx_stop(info);
	tx_stop(info);
	info->tx_count = info->tx_put = info->tx_get = 0;
	
	if (info->params.mode == MGSL_MODE_HDLC || info->netcount)
		hdlc_mode(info);
	else
		async_mode(info);
		
	set_signals(info);
	
	info->dcd_chkcount = 0;
	info->cts_chkcount = 0;
	info->ri_chkcount = 0;
	info->dsr_chkcount = 0;

	irq_enable(info, CHB, IRQ_DCD | IRQ_CTS);
	port_irq_enable(info, (unsigned char) PVR_DSR | PVR_RI);
	get_signals(info);
		
	if (info->netcount || info->tty->termios->c_cflag & CREAD)
		rx_start(info);
		
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Reconfigure adapter based on new parameters
 */
static void mgslpc_change_params(MGSLPC_INFO *info)
{
	unsigned cflag;
	int bits_per_char;

	if (!info->tty || !info->tty->termios)
		return;
		
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_change_params(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	cflag = info->tty->termios->c_cflag;

	/* if B0 rate (hangup) specified then negate DTR and RTS */
	/* otherwise assert DTR and RTS */
 	if (cflag & CBAUD)
		info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
	else
		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
	
	/* byte size and parity */
	
	switch (cflag & CSIZE) {
	case CS5: info->params.data_bits = 5; break;
	case CS6: info->params.data_bits = 6; break;
	case CS7: info->params.data_bits = 7; break;
	case CS8: info->params.data_bits = 8; break;
	default:  info->params.data_bits = 7; break;
	}
	      
	if (cflag & CSTOPB)
		info->params.stop_bits = 2;
	else
		info->params.stop_bits = 1;

	info->params.parity = ASYNC_PARITY_NONE;
	if (cflag & PARENB) {
		if (cflag & PARODD)
			info->params.parity = ASYNC_PARITY_ODD;
		else
			info->params.parity = ASYNC_PARITY_EVEN;
#ifdef CMSPAR
		if (cflag & CMSPAR)
			info->params.parity = ASYNC_PARITY_SPACE;
#endif
	}

	/* calculate number of jiffies to transmit a full
	 * FIFO (32 bytes) at specified data rate
	 */
	bits_per_char = info->params.data_bits + 
			info->params.stop_bits + 1;

	/* if port data rate is set to 460800 or less then
	 * allow tty settings to override, otherwise keep the
	 * current data rate.
	 */
	if (info->params.data_rate <= 460800) {
		info->params.data_rate = tty_get_baud_rate(info->tty);
	}
	
	if ( info->params.data_rate ) {
		info->timeout = (32*HZ*bits_per_char) / 
				info->params.data_rate;
	}
	info->timeout += HZ/50;		/* Add .02 seconds of slop */

	if (cflag & CRTSCTS)
		info->flags |= ASYNC_CTS_FLOW;
	else
		info->flags &= ~ASYNC_CTS_FLOW;
		
	if (cflag & CLOCAL)
		info->flags &= ~ASYNC_CHECK_CD;
	else
		info->flags |= ASYNC_CHECK_CD;

	/* process tty input control flags */
	
	info->read_status_mask = 0;
	if (I_INPCK(info->tty))
		info->read_status_mask |= BIT7 | BIT6;
	if (I_IGNPAR(info->tty))
		info->ignore_status_mask |= BIT7 | BIT6;

	mgslpc_program_hw(info);
}

/* Add a character to the transmit buffer
 */
static void mgslpc_put_char(struct tty_struct *tty, unsigned char ch)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO) {
		printk( "%s(%d):mgslpc_put_char(%d) on %s\n",
			__FILE__,__LINE__,ch,info->device_name);
	}

	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_put_char"))
		return;

	if (!info->tx_buf)
		return;

	spin_lock_irqsave(&info->lock,flags);
	
	if (info->params.mode == MGSL_MODE_ASYNC || !info->tx_active) {
		if (info->tx_count < TXBUFSIZE - 1) {
			info->tx_buf[info->tx_put++] = ch;
			info->tx_put &= TXBUFSIZE-1;
			info->tx_count++;
		}
	}
	
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Enable transmitter so remaining characters in the
 * transmit buffer are sent.
 */
static void mgslpc_flush_chars(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
				
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk( "%s(%d):mgslpc_flush_chars() entry on %s tx_count=%d\n",
			__FILE__,__LINE__,info->device_name,info->tx_count);
	
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_flush_chars"))
		return;

	if (info->tx_count <= 0 || tty->stopped ||
	    tty->hw_stopped || !info->tx_buf)
		return;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk( "%s(%d):mgslpc_flush_chars() entry on %s starting transmitter\n",
			__FILE__,__LINE__,info->device_name);

	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Send a block of data
 * 	
 * Arguments:
 * 
 * tty        pointer to tty information structure
 * buf	      pointer to buffer containing send data
 * count      size of send data in bytes
 * 	
 * Returns: number of characters written
 */
static int mgslpc_write(struct tty_struct * tty,
			const unsigned char *buf, int count)
{
	int c, ret = 0;
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk( "%s(%d):mgslpc_write(%s) count=%d\n",
			__FILE__,__LINE__,info->device_name,count);
	
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_write") ||
		!info->tx_buf)
		goto cleanup;

	if (info->params.mode == MGSL_MODE_HDLC) {
		if (count > TXBUFSIZE) {
			ret = -EIO;
			goto cleanup;
		}
		if (info->tx_active)
			goto cleanup;
		else if (info->tx_count)
			goto start;
	}

	for (;;) {
		c = min(count,
			min(TXBUFSIZE - info->tx_count - 1,
			    TXBUFSIZE - info->tx_put));
		if (c <= 0)
			break;
			
		memcpy(info->tx_buf + info->tx_put, buf, c);

		spin_lock_irqsave(&info->lock,flags);
		info->tx_put = (info->tx_put + c) & (TXBUFSIZE-1);
		info->tx_count += c;
		spin_unlock_irqrestore(&info->lock,flags);

		buf += c;
		count -= c;
		ret += c;
	}
start:
 	if (info->tx_count && !tty->stopped && !tty->hw_stopped) {
		spin_lock_irqsave(&info->lock,flags);
		if (!info->tx_active)
		 	tx_start(info);
		spin_unlock_irqrestore(&info->lock,flags);
 	}
cleanup:	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk( "%s(%d):mgslpc_write(%s) returning=%d\n",
			__FILE__,__LINE__,info->device_name,ret);
	return ret;
}

/* Return the count of free bytes in transmit buffer
 */
static int mgslpc_write_room(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	int ret;
				
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_write_room"))
		return 0;

	if (info->params.mode == MGSL_MODE_HDLC) {
		/* HDLC (frame oriented) mode */
		if (info->tx_active)
			return 0;
		else
			return HDLC_MAX_FRAME_SIZE;
	} else {
		ret = TXBUFSIZE - info->tx_count - 1;
		if (ret < 0)
			ret = 0;
	}
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_write_room(%s)=%d\n",
			 __FILE__,__LINE__, info->device_name, ret);
	return ret;
}

/* Return the count of bytes in transmit buffer
 */
static int mgslpc_chars_in_buffer(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	int rc;
		 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_chars_in_buffer(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_chars_in_buffer"))
		return 0;
		
	if (info->params.mode == MGSL_MODE_HDLC)
		rc = info->tx_active ? info->max_frame_size : 0;
	else
		rc = info->tx_count;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_chars_in_buffer(%s)=%d\n",
			 __FILE__,__LINE__, info->device_name, rc);
			 
	return rc;
}

/* Discard all data in the send buffer
 */
static void mgslpc_flush_buffer(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_flush_buffer(%s) entry\n",
			 __FILE__,__LINE__, info->device_name );
	
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_flush_buffer"))
		return;
		
	spin_lock_irqsave(&info->lock,flags); 
	info->tx_count = info->tx_put = info->tx_get = 0;
	del_timer(&info->tx_timer);	
	spin_unlock_irqrestore(&info->lock,flags);

	wake_up_interruptible(&tty->write_wait);
	tty_wakeup(tty);
}

/* Send a high-priority XON/XOFF character
 */
static void mgslpc_send_xchar(struct tty_struct *tty, char ch)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_send_xchar(%s,%d)\n",
			 __FILE__,__LINE__, info->device_name, ch );
			 
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_send_xchar"))
		return;

	info->x_char = ch;
	if (ch) {
		spin_lock_irqsave(&info->lock,flags);
		if (!info->tx_enabled)
		 	tx_start(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

/* Signal remote device to throttle send data (our receive data)
 */
static void mgslpc_throttle(struct tty_struct * tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_throttle(%s) entry\n",
			 __FILE__,__LINE__, info->device_name );

	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_throttle"))
		return;
	
	if (I_IXOFF(tty))
		mgslpc_send_xchar(tty, STOP_CHAR(tty));
 
 	if (tty->termios->c_cflag & CRTSCTS) {
		spin_lock_irqsave(&info->lock,flags);
		info->serial_signals &= ~SerialSignal_RTS;
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

/* Signal remote device to stop throttling send data (our receive data)
 */
static void mgslpc_unthrottle(struct tty_struct * tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_unthrottle(%s) entry\n",
			 __FILE__,__LINE__, info->device_name );

	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_unthrottle"))
		return;
	
	if (I_IXOFF(tty)) {
		if (info->x_char)
			info->x_char = 0;
		else
			mgslpc_send_xchar(tty, START_CHAR(tty));
	}
	
 	if (tty->termios->c_cflag & CRTSCTS) {
		spin_lock_irqsave(&info->lock,flags);
		info->serial_signals |= SerialSignal_RTS;
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
}

/* get the current serial statistics
 */
static int get_stats(MGSLPC_INFO * info, struct mgsl_icount __user *user_icount)
{
	int err;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("get_params(%s)\n", info->device_name);
	if (!user_icount) {
		memset(&info->icount, 0, sizeof(info->icount));
	} else {
		COPY_TO_USER(err, user_icount, &info->icount, sizeof(struct mgsl_icount));
		if (err)
			return -EFAULT;
	}
	return 0;
}

/* get the current serial parameters
 */
static int get_params(MGSLPC_INFO * info, MGSL_PARAMS __user *user_params)
{
	int err;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("get_params(%s)\n", info->device_name);
	COPY_TO_USER(err,user_params, &info->params, sizeof(MGSL_PARAMS));
	if (err)
		return -EFAULT;
	return 0;
}

/* set the serial parameters
 * 	
 * Arguments:
 * 
 * 	info		pointer to device instance data
 * 	new_params	user buffer containing new serial params
 *
 * Returns:	0 if success, otherwise error code
 */
static int set_params(MGSLPC_INFO * info, MGSL_PARAMS __user *new_params)
{
 	unsigned long flags;
	MGSL_PARAMS tmp_params;
	int err;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):set_params %s\n", __FILE__,__LINE__,
			info->device_name );
	COPY_FROM_USER(err,&tmp_params, new_params, sizeof(MGSL_PARAMS));
	if (err) {
		if ( debug_level >= DEBUG_LEVEL_INFO )
			printk( "%s(%d):set_params(%s) user buffer copy failed\n",
				__FILE__,__LINE__,info->device_name);
		return -EFAULT;
	}
	
	spin_lock_irqsave(&info->lock,flags);
	memcpy(&info->params,&tmp_params,sizeof(MGSL_PARAMS));
	spin_unlock_irqrestore(&info->lock,flags);
	
 	mgslpc_change_params(info);
	
	return 0;
}

static int get_txidle(MGSLPC_INFO * info, int __user *idle_mode)
{
	int err;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("get_txidle(%s)=%d\n", info->device_name, info->idle_mode);
	COPY_TO_USER(err,idle_mode, &info->idle_mode, sizeof(int));
	if (err)
		return -EFAULT;
	return 0;
}

static int set_txidle(MGSLPC_INFO * info, int idle_mode)
{
 	unsigned long flags;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("set_txidle(%s,%d)\n", info->device_name, idle_mode);
	spin_lock_irqsave(&info->lock,flags);
	info->idle_mode = idle_mode;
	tx_set_idle(info);
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int get_interface(MGSLPC_INFO * info, int __user *if_mode)
{
	int err;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("get_interface(%s)=%d\n", info->device_name, info->if_mode);
	COPY_TO_USER(err,if_mode, &info->if_mode, sizeof(int));
	if (err)
		return -EFAULT;
	return 0;
}

static int set_interface(MGSLPC_INFO * info, int if_mode)
{
 	unsigned long flags;
	unsigned char val;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("set_interface(%s,%d)\n", info->device_name, if_mode);
	spin_lock_irqsave(&info->lock,flags);
	info->if_mode = if_mode;

	val = read_reg(info, PVR) & 0x0f;
	switch (info->if_mode)
	{
	case MGSL_INTERFACE_RS232: val |= PVR_RS232; break;
	case MGSL_INTERFACE_V35:   val |= PVR_V35;   break;
	case MGSL_INTERFACE_RS422: val |= PVR_RS422; break;
	}
	write_reg(info, PVR, val);

	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int set_txenable(MGSLPC_INFO * info, int enable)
{
 	unsigned long flags;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("set_txenable(%s,%d)\n", info->device_name, enable);
			
	spin_lock_irqsave(&info->lock,flags);
	if (enable) {
		if (!info->tx_enabled)
			tx_start(info);
	} else {
		if (info->tx_enabled)
			tx_stop(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int tx_abort(MGSLPC_INFO * info)
{
 	unsigned long flags;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_abort(%s)\n", info->device_name);
			
	spin_lock_irqsave(&info->lock,flags);
	if (info->tx_active && info->tx_count &&
	    info->params.mode == MGSL_MODE_HDLC) {
		/* clear data count so FIFO is not filled on next IRQ.
		 * This results in underrun and abort transmission.
		 */
		info->tx_count = info->tx_put = info->tx_get = 0;
		info->tx_aborting = TRUE;
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int set_rxenable(MGSLPC_INFO * info, int enable)
{
 	unsigned long flags;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("set_rxenable(%s,%d)\n", info->device_name, enable);
			
	spin_lock_irqsave(&info->lock,flags);
	if (enable) {
		if (!info->rx_enabled)
			rx_start(info);
	} else {
		if (info->rx_enabled)
			rx_stop(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/* wait for specified event to occur
 * 	
 * Arguments:	 	info	pointer to device instance data
 * 			mask	pointer to bitmask of events to wait for
 * Return Value:	0 	if successful and bit mask updated with
 *				of events triggerred,
 * 			otherwise error code
 */
static int wait_events(MGSLPC_INFO * info, int __user *mask_ptr)
{
 	unsigned long flags;
	int s;
	int rc=0;
	struct mgsl_icount cprev, cnow;
	int events;
	int mask;
	struct	_input_signal_events oldsigs, newsigs;
	DECLARE_WAITQUEUE(wait, current);

	COPY_FROM_USER(rc,&mask, mask_ptr, sizeof(int));
	if (rc)
		return  -EFAULT;
		 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("wait_events(%s,%d)\n", info->device_name, mask);

	spin_lock_irqsave(&info->lock,flags);

	/* return immediately if state matches requested events */
	get_signals(info);
	s = info->serial_signals;
	events = mask &
		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
 		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
	if (events) {
		spin_unlock_irqrestore(&info->lock,flags);
		goto exit;
	}

	/* save current irq counts */
	cprev = info->icount;
	oldsigs = info->input_signal_events;
	
	if ((info->params.mode == MGSL_MODE_HDLC) &&
	    (mask & MgslEvent_ExitHuntMode))
		irq_enable(info, CHA, IRQ_EXITHUNT);
	
	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&info->event_wait_q, &wait);
	
	spin_unlock_irqrestore(&info->lock,flags);
	
	
	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
			
		/* get current irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		newsigs = info->input_signal_events;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
		    newsigs.dsr_down == oldsigs.dsr_down &&
		    newsigs.dcd_up   == oldsigs.dcd_up   &&
		    newsigs.dcd_down == oldsigs.dcd_down &&
		    newsigs.cts_up   == oldsigs.cts_up   &&
		    newsigs.cts_down == oldsigs.cts_down &&
		    newsigs.ri_up    == oldsigs.ri_up    &&
		    newsigs.ri_down  == oldsigs.ri_down  &&
		    cnow.exithunt    == cprev.exithunt   &&
		    cnow.rxidle      == cprev.rxidle) {
			rc = -EIO;
			break;
		}

		events = mask &
			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
		if (events)
			break;
		
		cprev = cnow;
		oldsigs = newsigs;
	}
	
	remove_wait_queue(&info->event_wait_q, &wait);
	set_current_state(TASK_RUNNING);

	if (mask & MgslEvent_ExitHuntMode) {
		spin_lock_irqsave(&info->lock,flags);
		if (!waitqueue_active(&info->event_wait_q))
			irq_disable(info, CHA, IRQ_EXITHUNT);
		spin_unlock_irqrestore(&info->lock,flags);
	}
exit:
	if (rc == 0)
		PUT_USER(rc, events, mask_ptr);
	return rc;
}

static int modem_input_wait(MGSLPC_INFO *info,int arg)
{
 	unsigned long flags;
	int rc;
	struct mgsl_icount cprev, cnow;
	DECLARE_WAITQUEUE(wait, current);

	/* save current irq counts */
	spin_lock_irqsave(&info->lock,flags);
	cprev = info->icount;
	add_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	spin_unlock_irqrestore(&info->lock,flags);

	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}

		/* get new irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
			rc = -EIO;
			break;
		}

		/* check for change in caller specified modem input */
		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
			rc = 0;
			break;
		}

		cprev = cnow;
	}
	remove_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_RUNNING);
	return rc;
}

/* return the state of the serial control and status signals
 */
static int tiocmget(struct tty_struct *tty, struct file *file)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned int result;
 	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
 	get_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	result = ((info->serial_signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
		((info->serial_signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
		((info->serial_signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
		((info->serial_signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
		((info->serial_signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
		((info->serial_signals & SerialSignal_CTS) ? TIOCM_CTS:0);

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):%s tiocmget() value=%08X\n",
			 __FILE__,__LINE__, info->device_name, result );
	return result;
}

/* set modem control signals (DTR/RTS)
 */
static int tiocmset(struct tty_struct *tty, struct file *file,
		    unsigned int set, unsigned int clear)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
 	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):%s tiocmset(%x,%x)\n",
			__FILE__,__LINE__,info->device_name, set, clear);

	if (set & TIOCM_RTS)
		info->serial_signals |= SerialSignal_RTS;
	if (set & TIOCM_DTR)
		info->serial_signals |= SerialSignal_DTR;
	if (clear & TIOCM_RTS)
		info->serial_signals &= ~SerialSignal_RTS;
	if (clear & TIOCM_DTR)
		info->serial_signals &= ~SerialSignal_DTR;

	spin_lock_irqsave(&info->lock,flags);
 	set_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/* Set or clear transmit break condition
 *
 * Arguments:		tty		pointer to tty instance data
 *			break_state	-1=set break condition, 0=clear
 */
static void mgslpc_break(struct tty_struct *tty, int break_state)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_break(%s,%d)\n",
			 __FILE__,__LINE__, info->device_name, break_state);
			 
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_break"))
		return;

	spin_lock_irqsave(&info->lock,flags);
 	if (break_state == -1)
		set_reg_bits(info, CHA+DAFO, BIT6);
	else 
		clear_reg_bits(info, CHA+DAFO, BIT6);
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Service an IOCTL request
 * 	
 * Arguments:
 * 
 * 	tty	pointer to tty instance data
 * 	file	pointer to associated file object for device
 * 	cmd	IOCTL command code
 * 	arg	command argument/context
 * 	
 * Return Value:	0 if success, otherwise error code
 */
static int mgslpc_ioctl(struct tty_struct *tty, struct file * file,
			unsigned int cmd, unsigned long arg)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_ioctl %s cmd=%08X\n", __FILE__,__LINE__,
			info->device_name, cmd );
	
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_ioctl"))
		return -ENODEV;

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}

	return ioctl_common(info, cmd, arg);
}

static int ioctl_common(MGSLPC_INFO *info, unsigned int cmd, unsigned long arg)
{
	int error;
	struct mgsl_icount cnow;	/* kernel counter temps */
	struct serial_icounter_struct __user *p_cuser;	/* user space */
	void __user *argp = (void __user *)arg;
	unsigned long flags;
	
	switch (cmd) {
	case MGSL_IOCGPARAMS:
		return get_params(info, argp);
	case MGSL_IOCSPARAMS:
		return set_params(info, argp);
	case MGSL_IOCGTXIDLE:
		return get_txidle(info, argp);
	case MGSL_IOCSTXIDLE:
		return set_txidle(info, (int)arg);
	case MGSL_IOCGIF:
		return get_interface(info, argp);
	case MGSL_IOCSIF:
		return set_interface(info,(int)arg);
	case MGSL_IOCTXENABLE:
		return set_txenable(info,(int)arg);
	case MGSL_IOCRXENABLE:
		return set_rxenable(info,(int)arg);
	case MGSL_IOCTXABORT:
		return tx_abort(info);
	case MGSL_IOCGSTATS:
		return get_stats(info, argp);
	case MGSL_IOCWAITEVENT:
		return wait_events(info, argp);
	case TIOCMIWAIT:
		return modem_input_wait(info,(int)arg);
	case TIOCGICOUNT:
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		spin_unlock_irqrestore(&info->lock,flags);
		p_cuser = argp;
		PUT_USER(error,cnow.cts, &p_cuser->cts);
		if (error) return error;
		PUT_USER(error,cnow.dsr, &p_cuser->dsr);
		if (error) return error;
		PUT_USER(error,cnow.rng, &p_cuser->rng);
		if (error) return error;
		PUT_USER(error,cnow.dcd, &p_cuser->dcd);
		if (error) return error;
		PUT_USER(error,cnow.rx, &p_cuser->rx);
		if (error) return error;
		PUT_USER(error,cnow.tx, &p_cuser->tx);
		if (error) return error;
		PUT_USER(error,cnow.frame, &p_cuser->frame);
		if (error) return error;
		PUT_USER(error,cnow.overrun, &p_cuser->overrun);
		if (error) return error;
		PUT_USER(error,cnow.parity, &p_cuser->parity);
		if (error) return error;
		PUT_USER(error,cnow.brk, &p_cuser->brk);
		if (error) return error;
		PUT_USER(error,cnow.buf_overrun, &p_cuser->buf_overrun);
		if (error) return error;
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

/* Set new termios settings
 * 	
 * Arguments:
 * 
 * 	tty		pointer to tty structure
 * 	termios		pointer to buffer to hold returned old termios
 */
static void mgslpc_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_set_termios %s\n", __FILE__,__LINE__,
			tty->driver->name );
	
	/* just return if nothing has changed */
	if ((tty->termios->c_cflag == old_termios->c_cflag)
	    && (RELEVANT_IFLAG(tty->termios->c_iflag) 
		== RELEVANT_IFLAG(old_termios->c_iflag)))
	  return;

	mgslpc_change_params(info);

	/* Handle transition to B0 status */
	if (old_termios->c_cflag & CBAUD &&
	    !(tty->termios->c_cflag & CBAUD)) {
		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
		spin_lock_irqsave(&info->lock,flags);
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
	
	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) &&
	    tty->termios->c_cflag & CBAUD) {
		info->serial_signals |= SerialSignal_DTR;
 		if (!(tty->termios->c_cflag & CRTSCTS) || 
 		    !test_bit(TTY_THROTTLED, &tty->flags)) {
			info->serial_signals |= SerialSignal_RTS;
 		}
		spin_lock_irqsave(&info->lock,flags);
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
	
	/* Handle turning off CRTSCTS */
	if (old_termios->c_cflag & CRTSCTS &&
	    !(tty->termios->c_cflag & CRTSCTS)) {
		tty->hw_stopped = 0;
		tx_release(tty);
	}
}

static void mgslpc_close(struct tty_struct *tty, struct file * filp)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;

	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_close"))
		return;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_close(%s) entry, count=%d\n",
			 __FILE__,__LINE__, info->device_name, info->count);
			 
	if (!info->count)
		return;

	if (tty_hung_up_p(filp))
		goto cleanup;
			
	if ((tty->count == 1) && (info->count != 1)) {
		/*
		 * tty->count is 1 and the tty structure will be freed.
		 * info->count should be one in this case.
		 * if it's not, correct it so that the port is shutdown.
		 */
		printk("mgslpc_close: bad refcount; tty->count is 1, "
		       "info->count is %d\n", info->count);
		info->count = 1;
	}
	
	info->count--;
	
	/* if at least one open remaining, leave hardware active */
	if (info->count)
		goto cleanup;
	
	info->flags |= ASYNC_CLOSING;
	
	/* set tty->closing to notify line discipline to 
	 * only process XON/XOFF characters. Only the N_TTY
	 * discipline appears to use this (ppp does not).
	 */
	tty->closing = 1;
	
	/* wait for transmit data to clear all layers */
	
	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
		if (debug_level >= DEBUG_LEVEL_INFO)
			printk("%s(%d):mgslpc_close(%s) calling tty_wait_until_sent\n",
				 __FILE__,__LINE__, info->device_name );
		tty_wait_until_sent(tty, info->closing_wait);
	}
		
 	if (info->flags & ASYNC_INITIALIZED)
 		mgslpc_wait_until_sent(tty, info->timeout);

	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);

	ldisc_flush_buffer(tty);
		
	shutdown(info);
	
	tty->closing = 0;
	info->tty = NULL;
	
	if (info->blocked_open) {
		if (info->close_delay) {
			msleep_interruptible(jiffies_to_msecs(info->close_delay));
		}
		wake_up_interruptible(&info->open_wait);
	}
	
	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
			 
	wake_up_interruptible(&info->close_wait);
	
cleanup:			
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_close(%s) exit, count=%d\n", __FILE__,__LINE__,
			tty->driver->name, info->count);
}

/* Wait until the transmitter is empty.
 */
static void mgslpc_wait_until_sent(struct tty_struct *tty, int timeout)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long orig_jiffies, char_time;

	if (!info )
		return;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_wait_until_sent(%s) entry\n",
			 __FILE__,__LINE__, info->device_name );
      
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_wait_until_sent"))
		return;

	if (!(info->flags & ASYNC_INITIALIZED))
		goto exit;
	 
	orig_jiffies = jiffies;
      
	/* Set check interval to 1/5 of estimated time to
	 * send a character, and make it at least 1. The check
	 * interval should also be less than the timeout.
	 * Note: use tight timings here to satisfy the NIST-PCTS.
	 */ 
       
	if ( info->params.data_rate ) {
	       	char_time = info->timeout/(32 * 5);
		if (!char_time)
			char_time++;
	} else
		char_time = 1;
		
	if (timeout)
		char_time = min_t(unsigned long, char_time, timeout);
		
	if (info->params.mode == MGSL_MODE_HDLC) {
		while (info->tx_active) {
			msleep_interruptible(jiffies_to_msecs(char_time));
			if (signal_pending(current))
				break;
			if (timeout && time_after(jiffies, orig_jiffies + timeout))
				break;
		}
	} else {
		while ((info->tx_count || info->tx_active) &&
			info->tx_enabled) {
			msleep_interruptible(jiffies_to_msecs(char_time));
			if (signal_pending(current))
				break;
			if (timeout && time_after(jiffies, orig_jiffies + timeout))
				break;
		}
	}
      
exit:
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_wait_until_sent(%s) exit\n",
			 __FILE__,__LINE__, info->device_name );
}

/* Called by tty_hangup() when a hangup is signaled.
 * This is the same as closing all open files for the port.
 */
static void mgslpc_hangup(struct tty_struct *tty)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_hangup(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_hangup"))
		return;

	mgslpc_flush_buffer(tty);
	shutdown(info);
	
	info->count = 0;	
	info->flags &= ~ASYNC_NORMAL_ACTIVE;
	info->tty = NULL;

	wake_up_interruptible(&info->open_wait);
}

/* Block the current process until the specified port
 * is ready to be opened.
 */
static int block_til_ready(struct tty_struct *tty, struct file *filp,
			   MGSLPC_INFO *info)
{
	DECLARE_WAITQUEUE(wait, current);
	int		retval;
	int		do_clocal = 0, extra_count = 0;
	unsigned long	flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):block_til_ready on %s\n",
			 __FILE__,__LINE__, tty->driver->name );

	if (filp->f_flags & O_NONBLOCK || tty->flags & (1 << TTY_IO_ERROR)){
		/* nonblock mode is set or port is not enabled */
		/* just verify that callout device is not active */
		info->flags |= ASYNC_NORMAL_ACTIVE;
		return 0;
	}

	if (tty->termios->c_cflag & CLOCAL)
		do_clocal = 1;

	/* Wait for carrier detect and the line to become
	 * free (i.e., not in use by the callout).  While we are in
	 * this loop, info->count is dropped by one, so that
	 * mgslpc_close() knows when to free things.  We restore it upon
	 * exit, either normal or abnormal.
	 */
	 
	retval = 0;
	add_wait_queue(&info->open_wait, &wait);
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):block_til_ready before block on %s count=%d\n",
			 __FILE__,__LINE__, tty->driver->name, info->count );

	spin_lock_irqsave(&info->lock, flags);
	if (!tty_hung_up_p(filp)) {
		extra_count = 1;
		info->count--;
	}
	spin_unlock_irqrestore(&info->lock, flags);
	info->blocked_open++;
	
	while (1) {
		if ((tty->termios->c_cflag & CBAUD)) {
			spin_lock_irqsave(&info->lock,flags);
			info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
		 	set_signals(info);
			spin_unlock_irqrestore(&info->lock,flags);
		}
		
		set_current_state(TASK_INTERRUPTIBLE);
		
		if (tty_hung_up_p(filp) || !(info->flags & ASYNC_INITIALIZED)){
			retval = (info->flags & ASYNC_HUP_NOTIFY) ?
					-EAGAIN : -ERESTARTSYS;
			break;
		}
		
		spin_lock_irqsave(&info->lock,flags);
	 	get_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
		
 		if (!(info->flags & ASYNC_CLOSING) &&
 		    (do_clocal || (info->serial_signals & SerialSignal_DCD)) ) {
 			break;
		}
			
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		
		if (debug_level >= DEBUG_LEVEL_INFO)
			printk("%s(%d):block_til_ready blocking on %s count=%d\n",
				 __FILE__,__LINE__, tty->driver->name, info->count );
				 
		schedule();
	}
	
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&info->open_wait, &wait);
	
	if (extra_count)
		info->count++;
	info->blocked_open--;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):block_til_ready after blocking on %s count=%d\n",
			 __FILE__,__LINE__, tty->driver->name, info->count );
			 
	if (!retval)
		info->flags |= ASYNC_NORMAL_ACTIVE;
		
	return retval;
}

static int mgslpc_open(struct tty_struct *tty, struct file * filp)
{
	MGSLPC_INFO	*info;
	int 			retval, line;
	unsigned long flags;

	/* verify range of specified line number */	
	line = tty->index;
	if ((line < 0) || (line >= mgslpc_device_count)) {
		printk("%s(%d):mgslpc_open with invalid line #%d.\n",
			__FILE__,__LINE__,line);
		return -ENODEV;
	}

	/* find the info structure for the specified line */
	info = mgslpc_device_list;
	while(info && info->line != line)
		info = info->next_device;
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_open"))
		return -ENODEV;
	
	tty->driver_data = info;
	info->tty = tty;
		
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_open(%s), old ref count = %d\n",
			 __FILE__,__LINE__,tty->driver->name, info->count);

	/* If port is closing, signal caller to try again */
	if (tty_hung_up_p(filp) || info->flags & ASYNC_CLOSING){
		if (info->flags & ASYNC_CLOSING)
			interruptible_sleep_on(&info->close_wait);
		retval = ((info->flags & ASYNC_HUP_NOTIFY) ?
			-EAGAIN : -ERESTARTSYS);
		goto cleanup;
	}
	
	info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;

	spin_lock_irqsave(&info->netlock, flags);
	if (info->netcount) {
		retval = -EBUSY;
		spin_unlock_irqrestore(&info->netlock, flags);
		goto cleanup;
	}
	info->count++;
	spin_unlock_irqrestore(&info->netlock, flags);

	if (info->count == 1) {
		/* 1st open on this device, init hardware */
		retval = startup(info);
		if (retval < 0)
			goto cleanup;
	}

	retval = block_til_ready(tty, filp, info);
	if (retval) {
		if (debug_level >= DEBUG_LEVEL_INFO)
			printk("%s(%d):block_til_ready(%s) returned %d\n",
				 __FILE__,__LINE__, info->device_name, retval);
		goto cleanup;
	}

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_open(%s) success\n",
			 __FILE__,__LINE__, info->device_name);
	retval = 0;
	
cleanup:			
	if (retval) {
		if (tty->count == 1)
			info->tty = NULL; /* tty layer will release tty struct */
		if(info->count)
			info->count--;
	}
	
	return retval;
}

/*
 * /proc fs routines....
 */

static inline int line_info(char *buf, MGSLPC_INFO *info)
{
	char	stat_buf[30];
	int	ret;
	unsigned long flags;

	ret = sprintf(buf, "%s:io:%04X irq:%d",
		      info->device_name, info->io_base, info->irq_level);

	/* output current serial signal states */
	spin_lock_irqsave(&info->lock,flags);
 	get_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);
	
	stat_buf[0] = 0;
	stat_buf[1] = 0;
	if (info->serial_signals & SerialSignal_RTS)
		strcat(stat_buf, "|RTS");
	if (info->serial_signals & SerialSignal_CTS)
		strcat(stat_buf, "|CTS");
	if (info->serial_signals & SerialSignal_DTR)
		strcat(stat_buf, "|DTR");
	if (info->serial_signals & SerialSignal_DSR)
		strcat(stat_buf, "|DSR");
	if (info->serial_signals & SerialSignal_DCD)
		strcat(stat_buf, "|CD");
	if (info->serial_signals & SerialSignal_RI)
		strcat(stat_buf, "|RI");

	if (info->params.mode == MGSL_MODE_HDLC) {
		ret += sprintf(buf+ret, " HDLC txok:%d rxok:%d",
			      info->icount.txok, info->icount.rxok);
		if (info->icount.txunder)
			ret += sprintf(buf+ret, " txunder:%d", info->icount.txunder);
		if (info->icount.txabort)
			ret += sprintf(buf+ret, " txabort:%d", info->icount.txabort);
		if (info->icount.rxshort)
			ret += sprintf(buf+ret, " rxshort:%d", info->icount.rxshort);	
		if (info->icount.rxlong)
			ret += sprintf(buf+ret, " rxlong:%d", info->icount.rxlong);
		if (info->icount.rxover)
			ret += sprintf(buf+ret, " rxover:%d", info->icount.rxover);
		if (info->icount.rxcrc)
			ret += sprintf(buf+ret, " rxcrc:%d", info->icount.rxcrc);
	} else {
		ret += sprintf(buf+ret, " ASYNC tx:%d rx:%d",
			      info->icount.tx, info->icount.rx);
		if (info->icount.frame)
			ret += sprintf(buf+ret, " fe:%d", info->icount.frame);
		if (info->icount.parity)
			ret += sprintf(buf+ret, " pe:%d", info->icount.parity);
		if (info->icount.brk)
			ret += sprintf(buf+ret, " brk:%d", info->icount.brk);	
		if (info->icount.overrun)
			ret += sprintf(buf+ret, " oe:%d", info->icount.overrun);
	}
	
	/* Append serial signal status to end */
	ret += sprintf(buf+ret, " %s\n", stat_buf+1);
	
	ret += sprintf(buf+ret, "txactive=%d bh_req=%d bh_run=%d pending_bh=%x\n",
		       info->tx_active,info->bh_requested,info->bh_running,
		       info->pending_bh);
	
	return ret;
}

/* Called to print information about devices
 */
static int mgslpc_read_proc(char *page, char **start, off_t off, int count,
		 int *eof, void *data)
{
	int len = 0, l;
	off_t	begin = 0;
	MGSLPC_INFO *info;
	
	len += sprintf(page, "synclink driver:%s\n", driver_version);
	
	info = mgslpc_device_list;
	while( info ) {
		l = line_info(page + len, info);
		len += l;
		if (len+begin > off+count)
			goto done;
		if (len+begin < off) {
			begin += len;
			len = 0;
		}
		info = info->next_device;
	}

	*eof = 1;
done:
	if (off >= len+begin)
		return 0;
	*start = page + (off-begin);
	return ((count < begin+len-off) ? count : begin+len-off);
}

static int rx_alloc_buffers(MGSLPC_INFO *info)
{
	/* each buffer has header and data */
	info->rx_buf_size = sizeof(RXBUF) + info->max_frame_size;

	/* calculate total allocation size for 8 buffers */
	info->rx_buf_total_size = info->rx_buf_size * 8;

	/* limit total allocated memory */
	if (info->rx_buf_total_size > 0x10000)
		info->rx_buf_total_size = 0x10000;

	/* calculate number of buffers */
	info->rx_buf_count = info->rx_buf_total_size / info->rx_buf_size;

	info->rx_buf = kmalloc(info->rx_buf_total_size, GFP_KERNEL);
	if (info->rx_buf == NULL)
		return -ENOMEM;

	rx_reset_buffers(info);
	return 0;
}

static void rx_free_buffers(MGSLPC_INFO *info)
{
	kfree(info->rx_buf);
	info->rx_buf = NULL;
}

static int claim_resources(MGSLPC_INFO *info)
{
	if (rx_alloc_buffers(info) < 0 ) {
		printk( "Cant allocate rx buffer %s\n", info->device_name);
		release_resources(info);
		return -ENODEV;
	}	
	return 0;
}

static void release_resources(MGSLPC_INFO *info)
{
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("release_resources(%s)\n", info->device_name);
	rx_free_buffers(info);
}

/* Add the specified device instance data structure to the
 * global linked list of devices and increment the device count.
 * 	
 * Arguments:		info	pointer to device instance data
 */
static void mgslpc_add_device(MGSLPC_INFO *info)
{
	info->next_device = NULL;
	info->line = mgslpc_device_count;
	sprintf(info->device_name,"ttySLP%d",info->line);
	
	if (info->line < MAX_DEVICE_COUNT) {
		if (maxframe[info->line])
			info->max_frame_size = maxframe[info->line];
		info->dosyncppp = dosyncppp[info->line];
	}

	mgslpc_device_count++;
	
	if (!mgslpc_device_list)
		mgslpc_device_list = info;
	else {	
		MGSLPC_INFO *current_dev = mgslpc_device_list;
		while( current_dev->next_device )
			current_dev = current_dev->next_device;
		current_dev->next_device = info;
	}
	
	if (info->max_frame_size < 4096)
		info->max_frame_size = 4096;
	else if (info->max_frame_size > 65535)
		info->max_frame_size = 65535;
	
	printk( "SyncLink PC Card %s:IO=%04X IRQ=%d\n",
		info->device_name, info->io_base, info->irq_level);

#ifdef CONFIG_HDLC
	hdlcdev_init(info);
#endif
}

static void mgslpc_remove_device(MGSLPC_INFO *remove_info)
{
	MGSLPC_INFO *info = mgslpc_device_list;
	MGSLPC_INFO *last = NULL;

	while(info) {
		if (info == remove_info) {
			if (last)
				last->next_device = info->next_device;
			else
				mgslpc_device_list = info->next_device;
#ifdef CONFIG_HDLC
			hdlcdev_exit(info);
#endif
			release_resources(info);
			kfree(info);
			mgslpc_device_count--;
			return;
		}
		last = info;
		info = info->next_device;
	}
}

static struct pcmcia_device_id mgslpc_ids[] = {
	PCMCIA_DEVICE_MANF_CARD(0x02c5, 0x0050),
	PCMCIA_DEVICE_NULL
};
MODULE_DEVICE_TABLE(pcmcia, mgslpc_ids);

static struct pcmcia_driver mgslpc_driver = {
	.owner		= THIS_MODULE,
	.drv		= {
		.name	= "synclink_cs",
	},
	.probe		= mgslpc_probe,
	.remove		= mgslpc_detach,
	.id_table	= mgslpc_ids,
	.suspend	= mgslpc_suspend,
	.resume		= mgslpc_resume,
};

static const struct tty_operations mgslpc_ops = {
	.open = mgslpc_open,
	.close = mgslpc_close,
	.write = mgslpc_write,
	.put_char = mgslpc_put_char,
	.flush_chars = mgslpc_flush_chars,
	.write_room = mgslpc_write_room,
	.chars_in_buffer = mgslpc_chars_in_buffer,
	.flush_buffer = mgslpc_flush_buffer,
	.ioctl = mgslpc_ioctl,
	.throttle = mgslpc_throttle,
	.unthrottle = mgslpc_unthrottle,
	.send_xchar = mgslpc_send_xchar,
	.break_ctl = mgslpc_break,
	.wait_until_sent = mgslpc_wait_until_sent,
	.read_proc = mgslpc_read_proc,
	.set_termios = mgslpc_set_termios,
	.stop = tx_pause,
	.start = tx_release,
	.hangup = mgslpc_hangup,
	.tiocmget = tiocmget,
	.tiocmset = tiocmset,
};

static void synclink_cs_cleanup(void)
{
	int rc;

	printk("Unloading %s: version %s\n", driver_name, driver_version);

	while(mgslpc_device_list)
		mgslpc_remove_device(mgslpc_device_list);

	if (serial_driver) {
		if ((rc = tty_unregister_driver(serial_driver)))
			printk("%s(%d) failed to unregister tty driver err=%d\n",
			       __FILE__,__LINE__,rc);
		put_tty_driver(serial_driver);
	}

	pcmcia_unregister_driver(&mgslpc_driver);
}

static int __init synclink_cs_init(void)
{
    int rc;

    if (break_on_load) {
	    mgslpc_get_text_ptr();
	    BREAKPOINT();
    }

    printk("%s %s\n", driver_name, driver_version);

    if ((rc = pcmcia_register_driver(&mgslpc_driver)) < 0)
	    return rc;

    serial_driver = alloc_tty_driver(MAX_DEVICE_COUNT);
    if (!serial_driver) {
	    rc = -ENOMEM;
	    goto error;
    }

    /* Initialize the tty_driver structure */
	
    serial_driver->owner = THIS_MODULE;
    serial_driver->driver_name = "synclink_cs";
    serial_driver->name = "ttySLP";
    serial_driver->major = ttymajor;
    serial_driver->minor_start = 64;
    serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
    serial_driver->subtype = SERIAL_TYPE_NORMAL;
    serial_driver->init_termios = tty_std_termios;
    serial_driver->init_termios.c_cflag =
	    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
    serial_driver->flags = TTY_DRIVER_REAL_RAW;
    tty_set_operations(serial_driver, &mgslpc_ops);

    if ((rc = tty_register_driver(serial_driver)) < 0) {
	    printk("%s(%d):Couldn't register serial driver\n",
		   __FILE__,__LINE__);
	    put_tty_driver(serial_driver);
	    serial_driver = NULL;
	    goto error;
    }
			
    printk("%s %s, tty major#%d\n",
	   driver_name, driver_version,
	   serial_driver->major);
	
    return 0;

error:
    synclink_cs_cleanup();
    return rc;
}

static void __exit synclink_cs_exit(void) 
{
	synclink_cs_cleanup();
}

module_init(synclink_cs_init);
module_exit(synclink_cs_exit);

static void mgslpc_set_rate(MGSLPC_INFO *info, unsigned char channel, unsigned int rate)
{
	unsigned int M, N;
	unsigned char val;

	/* note:standard BRG mode is broken in V3.2 chip 
	 * so enhanced mode is always used 
	 */

	if (rate) {
		N = 3686400 / rate;
		if (!N)
			N = 1;
		N >>= 1;
		for (M = 1; N > 64 && M < 16; M++)
			N >>= 1;
		N--;

		/* BGR[5..0] = N
		 * BGR[9..6] = M
		 * BGR[7..0] contained in BGR register
		 * BGR[9..8] contained in CCR2[7..6]
		 * divisor = (N+1)*2^M
		 *
		 * Note: M *must* not be zero (causes asymetric duty cycle)
		 */ 
		write_reg(info, (unsigned char) (channel + BGR),
				  (unsigned char) ((M << 6) + N));
		val = read_reg(info, (unsigned char) (channel + CCR2)) & 0x3f;
		val |= ((M << 4) & 0xc0);
		write_reg(info, (unsigned char) (channel + CCR2), val);
	}
}

/* Enabled the AUX clock output at the specified frequency.
 */
static void enable_auxclk(MGSLPC_INFO *info)
{
	unsigned char val;
	
	/* MODE
	 *
	 * 07..06  MDS[1..0] 10 = transparent HDLC mode
	 * 05      ADM Address Mode, 0 = no addr recognition
	 * 04      TMD Timer Mode, 0 = external
	 * 03      RAC Receiver Active, 0 = inactive
	 * 02      RTS 0=RTS active during xmit, 1=RTS always active
	 * 01      TRS Timer Resolution, 1=512
	 * 00      TLP Test Loop, 0 = no loop
	 *
	 * 1000 0010
	 */ 
	val = 0x82;
	
	/* channel B RTS is used to enable AUXCLK driver on SP505 */ 
	if (info->params.mode == MGSL_MODE_HDLC && info->params.clock_speed)
		val |= BIT2;
	write_reg(info, CHB + MODE, val);
	
	/* CCR0
	 *
	 * 07      PU Power Up, 1=active, 0=power down
	 * 06      MCE Master Clock Enable, 1=enabled
	 * 05      Reserved, 0
	 * 04..02  SC[2..0] Encoding
	 * 01..00  SM[1..0] Serial Mode, 00=HDLC
	 *
	 * 11000000
	 */ 
	write_reg(info, CHB + CCR0, 0xc0);
	
	/* CCR1
	 *
	 * 07      SFLG Shared Flag, 0 = disable shared flags
	 * 06      GALP Go Active On Loop, 0 = not used
	 * 05      GLP Go On Loop, 0 = not used
	 * 04      ODS Output Driver Select, 1=TxD is push-pull output
	 * 03      ITF Interframe Time Fill, 0=mark, 1=flag
	 * 02..00  CM[2..0] Clock Mode
	 *
	 * 0001 0111
	 */ 
	write_reg(info, CHB + CCR1, 0x17);
	
	/* CCR2 (Channel B)
	 *
	 * 07..06  BGR[9..8] Baud rate bits 9..8
	 * 05      BDF Baud rate divisor factor, 0=1, 1=BGR value
	 * 04      SSEL Clock source select, 1=submode b
	 * 03      TOE 0=TxCLK is input, 1=TxCLK is output
	 * 02      RWX Read/Write Exchange 0=disabled
	 * 01      C32, CRC select, 0=CRC-16, 1=CRC-32
	 * 00      DIV, data inversion 0=disabled, 1=enabled
	 *
	 * 0011 1000
	 */ 
	if (info->params.mode == MGSL_MODE_HDLC && info->params.clock_speed)
		write_reg(info, CHB + CCR2, 0x38);
	else
		write_reg(info, CHB + CCR2, 0x30);
	
	/* CCR4
	 *
	 * 07      MCK4 Master Clock Divide by 4, 1=enabled
	 * 06      EBRG Enhanced Baud Rate Generator Mode, 1=enabled
	 * 05      TST1 Test Pin, 0=normal operation
	 * 04      ICD Ivert Carrier Detect, 1=enabled (active low)
	 * 03..02  Reserved, must be 0
	 * 01..00  RFT[1..0] RxFIFO Threshold 00=32 bytes
	 *
	 * 0101 0000
	 */ 
	write_reg(info, CHB + CCR4, 0x50);
	
	/* if auxclk not enabled, set internal BRG so
	 * CTS transitions can be detected (requires TxC)
	 */ 
	if (info->params.mode == MGSL_MODE_HDLC && info->params.clock_speed)
		mgslpc_set_rate(info, CHB, info->params.clock_speed);
	else
		mgslpc_set_rate(info, CHB, 921600);
}

static void loopback_enable(MGSLPC_INFO *info) 
{
	unsigned char val;
	
	/* CCR1:02..00  CM[2..0] Clock Mode = 111 (clock mode 7) */ 
	val = read_reg(info, CHA + CCR1) | (BIT2 + BIT1 + BIT0);
	write_reg(info, CHA + CCR1, val);
	
	/* CCR2:04 SSEL Clock source select, 1=submode b */ 
	val = read_reg(info, CHA + CCR2) | (BIT4 + BIT5);
	write_reg(info, CHA + CCR2, val);
	
	/* set LinkSpeed if available, otherwise default to 2Mbps */ 
	if (info->params.clock_speed)
		mgslpc_set_rate(info, CHA, info->params.clock_speed);
	else
		mgslpc_set_rate(info, CHA, 1843200);
	
	/* MODE:00 TLP Test Loop, 1=loopback enabled */ 
	val = read_reg(info, CHA + MODE) | BIT0;
	write_reg(info, CHA + MODE, val);
}

static void hdlc_mode(MGSLPC_INFO *info)
{
	unsigned char val;
	unsigned char clkmode, clksubmode;

	/* disable all interrupts */ 
	irq_disable(info, CHA, 0xffff);
	irq_disable(info, CHB, 0xffff);
	port_irq_disable(info, 0xff);
	
	/* assume clock mode 0a, rcv=RxC xmt=TxC */ 
	clkmode = clksubmode = 0;
	if (info->params.flags & HDLC_FLAG_RXC_DPLL
	    && info->params.flags & HDLC_FLAG_TXC_DPLL) {
		/* clock mode 7a, rcv = DPLL, xmt = DPLL */ 
		clkmode = 7;
	} else if (info->params.flags & HDLC_FLAG_RXC_BRG
		 && info->params.flags & HDLC_FLAG_TXC_BRG) {
		/* clock mode 7b, rcv = BRG, xmt = BRG */ 
		clkmode = 7;
		clksubmode = 1;
	} else if (info->params.flags & HDLC_FLAG_RXC_DPLL) {
		if (info->params.flags & HDLC_FLAG_TXC_BRG) {
			/* clock mode 6b, rcv = DPLL, xmt = BRG/16 */ 
			clkmode = 6;
			clksubmode = 1;
		} else {
			/* clock mode 6a, rcv = DPLL, xmt = TxC */ 
			clkmode = 6;
		}
	} else if (info->params.flags & HDLC_FLAG_TXC_BRG) {
		/* clock mode 0b, rcv = RxC, xmt = BRG */ 
		clksubmode = 1;
	}
	
	/* MODE
	 *
	 * 07..06  MDS[1..0] 10 = transparent HDLC mode
	 * 05      ADM Address Mode, 0 = no addr recognition
	 * 04      TMD Timer Mode, 0 = external
	 * 03      RAC Receiver Active, 0 = inactive
	 * 02      RTS 0=RTS active during xmit, 1=RTS always active
	 * 01      TRS Timer Resolution, 1=512
	 * 00      TLP Test Loop, 0 = no loop
	 *
	 * 1000 0010
	 */ 
	val = 0x82;
	if (info->params.loopback)
		val |= BIT0;
	
	/* preserve RTS state */ 
	if (info->serial_signals & SerialSignal_RTS)
		val |= BIT2;
	write_reg(info, CHA + MODE, val);
	
	/* CCR0
	 *
	 * 07      PU Power Up, 1=active, 0=power down
	 * 06      MCE Master Clock Enable, 1=enabled
	 * 05      Reserved, 0
	 * 04..02  SC[2..0] Encoding
	 * 01..00  SM[1..0] Serial Mode, 00=HDLC
	 *
	 * 11000000
	 */ 
	val = 0xc0;
	switch (info->params.encoding)
	{
	case HDLC_ENCODING_NRZI:
		val |= BIT3;
		break;
	case HDLC_ENCODING_BIPHASE_SPACE:
		val |= BIT4;
		break;		// FM0
	case HDLC_ENCODING_BIPHASE_MARK:
		val |= BIT4 + BIT2;
		break;		// FM1
	case HDLC_ENCODING_BIPHASE_LEVEL:
		val |= BIT4 + BIT3;
		break;		// Manchester
	}
	write_reg(info, CHA + CCR0, val);
	
	/* CCR1
	 *
	 * 07      SFLG Shared Flag, 0 = disable shared flags
	 * 06      GALP Go Active On Loop, 0 = not used
	 * 05      GLP Go On Loop, 0 = not used
	 * 04      ODS Output Driver Select, 1=TxD is push-pull output
	 * 03      ITF Interframe Time Fill, 0=mark, 1=flag
	 * 02..00  CM[2..0] Clock Mode
	 *
	 * 0001 0000
	 */ 
	val = 0x10 + clkmode;
	write_reg(info, CHA + CCR1, val);
	
	/* CCR2
	 *
	 * 07..06  BGR[9..8] Baud rate bits 9..8
	 * 05      BDF Baud rate divisor factor, 0=1, 1=BGR value
	 * 04      SSEL Clock source select, 1=submode b
	 * 03      TOE 0=TxCLK is input, 0=TxCLK is input
	 * 02      RWX Read/Write Exchange 0=disabled
	 * 01      C32, CRC select, 0=CRC-16, 1=CRC-32
	 * 00      DIV, data inversion 0=disabled, 1=enabled
	 *
	 * 0000 0000
	 */ 
	val = 0x00;
	if (clkmode == 2 || clkmode == 3 || clkmode == 6
	    || clkmode == 7 || (clkmode == 0 && clksubmode == 1))
		val |= BIT5;
	if (clksubmode)
		val |= BIT4;
	if (info->params.crc_type == HDLC_CRC_32_CCITT)
		val |= BIT1;
	if (info->params.encoding == HDLC_ENCODING_NRZB)
		val |= BIT0;
	write_reg(info, CHA + CCR2, val);
	
	/* CCR3
	 *
	 * 07..06  PRE[1..0] Preamble count 00=1, 01=2, 10=4, 11=8
	 * 05      EPT Enable preamble transmission, 1=enabled
	 * 04      RADD Receive address pushed to FIFO, 0=disabled
	 * 03      CRL CRC Reset Level, 0=FFFF
	 * 02      RCRC Rx CRC 0=On 1=Off
	 * 01      TCRC Tx CRC 0=On 1=Off
	 * 00      PSD DPLL Phase Shift Disable
	 *
	 * 0000 0000
	 */ 
	val = 0x00;
	if (info->params.crc_type == HDLC_CRC_NONE)
		val |= BIT2 + BIT1;
	if (info->params.preamble != HDLC_PREAMBLE_PATTERN_NONE)
		val |= BIT5;
	switch (info->params.preamble_length)
	{
	case HDLC_PREAMBLE_LENGTH_16BITS:
		val |= BIT6;
		break;
	case HDLC_PREAMBLE_LENGTH_32BITS:
		val |= BIT6;
		break;
	case HDLC_PREAMBLE_LENGTH_64BITS:
		val |= BIT7 + BIT6;
		break;
	}
	write_reg(info, CHA + CCR3, val);
	
	/* PRE - Preamble pattern */ 
	val = 0;
	switch (info->params.preamble)
	{
	case HDLC_PREAMBLE_PATTERN_FLAGS: val = 0x7e; break;
	case HDLC_PREAMBLE_PATTERN_10:    val = 0xaa; break;
	case HDLC_PREAMBLE_PATTERN_01:    val = 0x55; break;
	case HDLC_PREAMBLE_PATTERN_ONES:  val = 0xff; break;
	}
	write_reg(info, CHA + PRE, val);
	
	/* CCR4
	 *
	 * 07      MCK4 Master Clock Divide by 4, 1=enabled
	 * 06      EBRG Enhanced Baud Rate Generator Mode, 1=enabled
	 * 05      TST1 Test Pin, 0=normal operation
	 * 04      ICD Ivert Carrier Detect, 1=enabled (active low)
	 * 03..02  Reserved, must be 0
	 * 01..00  RFT[1..0] RxFIFO Threshold 00=32 bytes
	 *
	 * 0101 0000
	 */ 
	val = 0x50;
	write_reg(info, CHA + CCR4, val);
	if (info->params.flags & HDLC_FLAG_RXC_DPLL)
		mgslpc_set_rate(info, CHA, info->params.clock_speed * 16);
	else
		mgslpc_set_rate(info, CHA, info->params.clock_speed);
	
	/* RLCR Receive length check register
	 *
	 * 7     1=enable receive length check
	 * 6..0  Max frame length = (RL + 1) * 32
	 */ 
	write_reg(info, CHA + RLCR, 0);
	
	/* XBCH Transmit Byte Count High
	 *
	 * 07      DMA mode, 0 = interrupt driven
	 * 06      NRM, 0=ABM (ignored)
	 * 05      CAS Carrier Auto Start
	 * 04      XC Transmit Continuously (ignored)
	 * 03..00  XBC[10..8] Transmit byte count bits 10..8
	 *
	 * 0000 0000
	 */ 
	val = 0x00;
	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
		val |= BIT5;
	write_reg(info, CHA + XBCH, val);
	enable_auxclk(info);
	if (info->params.loopback || info->testing_irq)
		loopback_enable(info);
	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
	{
		irq_enable(info, CHB, IRQ_CTS);
		/* PVR[3] 1=AUTO CTS active */ 
		set_reg_bits(info, CHA + PVR, BIT3);
	} else
		clear_reg_bits(info, CHA + PVR, BIT3);

	irq_enable(info, CHA,
			 IRQ_RXEOM + IRQ_RXFIFO + IRQ_ALLSENT +
			 IRQ_UNDERRUN + IRQ_TXFIFO);
	issue_command(info, CHA, CMD_TXRESET + CMD_RXRESET);
	wait_command_complete(info, CHA);
	read_reg16(info, CHA + ISR);	/* clear pending IRQs */
	
	/* Master clock mode enabled above to allow reset commands
	 * to complete even if no data clocks are present.
	 *
	 * Disable master clock mode for normal communications because
	 * V3.2 of the ESCC2 has a bug that prevents the transmit all sent
	 * IRQ when in master clock mode.
	 *
	 * Leave master clock mode enabled for IRQ test because the
	 * timer IRQ used by the test can only happen in master clock mode.
	 */ 
	if (!info->testing_irq)
		clear_reg_bits(info, CHA + CCR0, BIT6);

	tx_set_idle(info);

	tx_stop(info);
	rx_stop(info);
}

static void rx_stop(MGSLPC_INFO *info)
{
	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):rx_stop(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	/* MODE:03 RAC Receiver Active, 0=inactive */ 
	clear_reg_bits(info, CHA + MODE, BIT3);

	info->rx_enabled = 0;
	info->rx_overflow = 0;
}

static void rx_start(MGSLPC_INFO *info)
{
	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):rx_start(%s)\n",
			 __FILE__,__LINE__, info->device_name );

	rx_reset_buffers(info);
	info->rx_enabled = 0;
	info->rx_overflow = 0;

	/* MODE:03 RAC Receiver Active, 1=active */ 
	set_reg_bits(info, CHA + MODE, BIT3);

	info->rx_enabled = 1;
}

static void tx_start(MGSLPC_INFO *info)
{
	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):tx_start(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	if (info->tx_count) {
		/* If auto RTS enabled and RTS is inactive, then assert */
		/* RTS and set a flag indicating that the driver should */
		/* negate RTS when the transmission completes. */
		info->drop_rts_on_tx_done = 0;

		if (info->params.flags & HDLC_FLAG_AUTO_RTS) {
			get_signals(info);
			if (!(info->serial_signals & SerialSignal_RTS)) {
				info->serial_signals |= SerialSignal_RTS;
				set_signals(info);
				info->drop_rts_on_tx_done = 1;
			}
		}

		if (info->params.mode == MGSL_MODE_ASYNC) {
			if (!info->tx_active) {
				info->tx_active = 1;
				tx_ready(info);
			}
		} else {
			info->tx_active = 1;
			tx_ready(info);
			info->tx_timer.expires = jiffies + msecs_to_jiffies(5000);
			add_timer(&info->tx_timer);	
		}
	}

	if (!info->tx_enabled)
		info->tx_enabled = 1;
}

static void tx_stop(MGSLPC_INFO *info)
{
	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):tx_stop(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	del_timer(&info->tx_timer);	

	info->tx_enabled = 0;
	info->tx_active  = 0;
}

/* Reset the adapter to a known state and prepare it for further use.
 */
static void reset_device(MGSLPC_INFO *info)
{
	/* power up both channels (set BIT7) */ 
	write_reg(info, CHA + CCR0, 0x80);
	write_reg(info, CHB + CCR0, 0x80);
	write_reg(info, CHA + MODE, 0);
	write_reg(info, CHB + MODE, 0);
	
	/* disable all interrupts */ 
	irq_disable(info, CHA, 0xffff);
	irq_disable(info, CHB, 0xffff);
	port_irq_disable(info, 0xff);
	
	/* PCR Port Configuration Register
	 *
	 * 07..04  DEC[3..0] Serial I/F select outputs
	 * 03      output, 1=AUTO CTS control enabled
	 * 02      RI Ring Indicator input 0=active
	 * 01      DSR input 0=active
	 * 00      DTR output 0=active
	 *
	 * 0000 0110
	 */ 
	write_reg(info, PCR, 0x06);
	
	/* PVR Port Value Register
	 *
	 * 07..04  DEC[3..0] Serial I/F select (0000=disabled)
	 * 03      AUTO CTS output 1=enabled
	 * 02      RI Ring Indicator input
	 * 01      DSR input
	 * 00      DTR output (1=inactive)
	 *
	 * 0000 0001
	 */
//	write_reg(info, PVR, PVR_DTR);
	
	/* IPC Interrupt Port Configuration
	 *
	 * 07      VIS 1=Masked interrupts visible
	 * 06..05  Reserved, 0
	 * 04..03  SLA Slave address, 00 ignored
	 * 02      CASM Cascading Mode, 1=daisy chain
	 * 01..00  IC[1..0] Interrupt Config, 01=push-pull output, active low
	 *
	 * 0000 0101
	 */ 
	write_reg(info, IPC, 0x05);
}

static void async_mode(MGSLPC_INFO *info)
{
	unsigned char val;

	/* disable all interrupts */ 
	irq_disable(info, CHA, 0xffff);
	irq_disable(info, CHB, 0xffff);
	port_irq_disable(info, 0xff);
	
	/* MODE
	 *
	 * 07      Reserved, 0
	 * 06      FRTS RTS State, 0=active
	 * 05      FCTS Flow Control on CTS
	 * 04      FLON Flow Control Enable
	 * 03      RAC Receiver Active, 0 = inactive
	 * 02      RTS 0=Auto RTS, 1=manual RTS
	 * 01      TRS Timer Resolution, 1=512
	 * 00      TLP Test Loop, 0 = no loop
	 *
	 * 0000 0110
	 */ 
	val = 0x06;
	if (info->params.loopback)
		val |= BIT0;
	
	/* preserve RTS state */ 
	if (!(info->serial_signals & SerialSignal_RTS))
		val |= BIT6;
	write_reg(info, CHA + MODE, val);
	
	/* CCR0
	 *
	 * 07      PU Power Up, 1=active, 0=power down
	 * 06      MCE Master Clock Enable, 1=enabled
	 * 05      Reserved, 0
	 * 04..02  SC[2..0] Encoding, 000=NRZ
	 * 01..00  SM[1..0] Serial Mode, 11=Async
	 *
	 * 1000 0011
	 */ 
	write_reg(info, CHA + CCR0, 0x83);
	
	/* CCR1
	 *
	 * 07..05  Reserved, 0
	 * 04      ODS Output Driver Select, 1=TxD is push-pull output
	 * 03      BCR Bit Clock Rate, 1=16x
	 * 02..00  CM[2..0] Clock Mode, 111=BRG
	 *
	 * 0001 1111
	 */ 
	write_reg(info, CHA + CCR1, 0x1f);
	
	/* CCR2 (channel A)
	 *
	 * 07..06  BGR[9..8] Baud rate bits 9..8
	 * 05      BDF Baud rate divisor factor, 0=1, 1=BGR value
	 * 04      SSEL Clock source select, 1=submode b
	 * 03      TOE 0=TxCLK is input, 0=TxCLK is input
	 * 02      RWX Read/Write Exchange 0=disabled
	 * 01      Reserved, 0
	 * 00      DIV, data inversion 0=disabled, 1=enabled
	 *
	 * 0001 0000
	 */ 
	write_reg(info, CHA + CCR2, 0x10);
	
	/* CCR3
	 *
	 * 07..01  Reserved, 0
	 * 00      PSD DPLL Phase Shift Disable
	 *
	 * 0000 0000
	 */ 
	write_reg(info, CHA + CCR3, 0);
	
	/* CCR4
	 *
	 * 07      MCK4 Master Clock Divide by 4, 1=enabled
	 * 06      EBRG Enhanced Baud Rate Generator Mode, 1=enabled
	 * 05      TST1 Test Pin, 0=normal operation
	 * 04      ICD Ivert Carrier Detect, 1=enabled (active low)
	 * 03..00  Reserved, must be 0
	 *
	 * 0101 0000
	 */ 
	write_reg(info, CHA + CCR4, 0x50);
	mgslpc_set_rate(info, CHA, info->params.data_rate * 16);
	
	/* DAFO Data Format
	 *
	 * 07      Reserved, 0
	 * 06      XBRK transmit break, 0=normal operation
	 * 05      Stop bits (0=1, 1=2)
	 * 04..03  PAR[1..0] Parity (01=odd, 10=even)
	 * 02      PAREN Parity Enable
	 * 01..00  CHL[1..0] Character Length (00=8, 01=7)
	 *
	 */ 
	val = 0x00;
	if (info->params.data_bits != 8)
		val |= BIT0;	/* 7 bits */
	if (info->params.stop_bits != 1)
		val |= BIT5;
	if (info->params.parity != ASYNC_PARITY_NONE)
	{
		val |= BIT2;	/* Parity enable */
		if (info->params.parity == ASYNC_PARITY_ODD)
			val |= BIT3;
		else
			val |= BIT4;
	}
	write_reg(info, CHA + DAFO, val);
	
	/* RFC Rx FIFO Control
	 *
	 * 07      Reserved, 0
	 * 06      DPS, 1=parity bit not stored in data byte
	 * 05      DXS, 0=all data stored in FIFO (including XON/XOFF)
	 * 04      RFDF Rx FIFO Data Format, 1=status byte stored in FIFO
	 * 03..02  RFTH[1..0], rx threshold, 11=16 status + 16 data byte
	 * 01      Reserved, 0
	 * 00      TCDE Terminate Char Detect Enable, 0=disabled
	 *
	 * 0101 1100
	 */ 
	write_reg(info, CHA + RFC, 0x5c);
	
	/* RLCR Receive length check register
	 *
	 * Max frame length = (RL + 1) * 32
	 */ 
	write_reg(info, CHA + RLCR, 0);
	
	/* XBCH Transmit Byte Count High
	 *
	 * 07      DMA mode, 0 = interrupt driven
	 * 06      NRM, 0=ABM (ignored)
	 * 05      CAS Carrier Auto Start
	 * 04      XC Transmit Continuously (ignored)
	 * 03..00  XBC[10..8] Transmit byte count bits 10..8
	 *
	 * 0000 0000
	 */ 
	val = 0x00;
	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
		val |= BIT5;
	write_reg(info, CHA + XBCH, val);
	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
		irq_enable(info, CHA, IRQ_CTS);
	
	/* MODE:03 RAC Receiver Active, 1=active */ 
	set_reg_bits(info, CHA + MODE, BIT3);
	enable_auxclk(info);
	if (info->params.flags & HDLC_FLAG_AUTO_CTS) {
		irq_enable(info, CHB, IRQ_CTS);
		/* PVR[3] 1=AUTO CTS active */ 
		set_reg_bits(info, CHA + PVR, BIT3);
	} else
		clear_reg_bits(info, CHA + PVR, BIT3);
	irq_enable(info, CHA,
			  IRQ_RXEOM + IRQ_RXFIFO + IRQ_BREAK_ON + IRQ_RXTIME +
			  IRQ_ALLSENT + IRQ_TXFIFO);
	issue_command(info, CHA, CMD_TXRESET + CMD_RXRESET);
	wait_command_complete(info, CHA);
	read_reg16(info, CHA + ISR);	/* clear pending IRQs */
}

/* Set the HDLC idle mode for the transmitter.
 */
static void tx_set_idle(MGSLPC_INFO *info)
{
	/* Note: ESCC2 only supports flags and one idle modes */ 
	if (info->idle_mode == HDLC_TXIDLE_FLAGS)
		set_reg_bits(info, CHA + CCR1, BIT3);
	else
		clear_reg_bits(info, CHA + CCR1, BIT3);
}

/* get state of the V24 status (input) signals.
 */
static void get_signals(MGSLPC_INFO *info)
{
	unsigned char status = 0;
	
	/* preserve DTR and RTS */ 
	info->serial_signals &= SerialSignal_DTR + SerialSignal_RTS;

	if (read_reg(info, CHB + VSTR) & BIT7)
		info->serial_signals |= SerialSignal_DCD;
	if (read_reg(info, CHB + STAR) & BIT1)
		info->serial_signals |= SerialSignal_CTS;

	status = read_reg(info, CHA + PVR);
	if (!(status & PVR_RI))
		info->serial_signals |= SerialSignal_RI;
	if (!(status & PVR_DSR))
		info->serial_signals |= SerialSignal_DSR;
}

/* Set the state of DTR and RTS based on contents of
 * serial_signals member of device extension.
 */
static void set_signals(MGSLPC_INFO *info)
{
	unsigned char val;

	val = read_reg(info, CHA + MODE);
	if (info->params.mode == MGSL_MODE_ASYNC) {
		if (info->serial_signals & SerialSignal_RTS)
			val &= ~BIT6;
		else
			val |= BIT6;
	} else {
		if (info->serial_signals & SerialSignal_RTS)
			val |= BIT2;
		else
			val &= ~BIT2;
	}
	write_reg(info, CHA + MODE, val);

	if (info->serial_signals & SerialSignal_DTR)
		clear_reg_bits(info, CHA + PVR, PVR_DTR);
	else
		set_reg_bits(info, CHA + PVR, PVR_DTR);
}

static void rx_reset_buffers(MGSLPC_INFO *info)
{
	RXBUF *buf;
	int i;

	info->rx_put = 0;
	info->rx_get = 0;
	info->rx_frame_count = 0;
	for (i=0 ; i < info->rx_buf_count ; i++) {
		buf = (RXBUF*)(info->rx_buf + (i * info->rx_buf_size));
		buf->status = buf->count = 0;
	}
}

/* Attempt to return a received HDLC frame
 * Only frames received without errors are returned.
 *
 * Returns 1 if frame returned, otherwise 0
 */
static int rx_get_frame(MGSLPC_INFO *info)
{
	unsigned short status;
	RXBUF *buf;
	unsigned int framesize = 0;
	unsigned long flags;
	struct tty_struct *tty = info->tty;
	int return_frame = 0;
	
	if (info->rx_frame_count == 0)
		return 0;

	buf = (RXBUF*)(info->rx_buf + (info->rx_get * info->rx_buf_size));

	status = buf->status;

	/* 07  VFR  1=valid frame
	 * 06  RDO  1=data overrun
	 * 05  CRC  1=OK, 0=error
	 * 04  RAB  1=frame aborted
	 */
	if ((status & 0xf0) != 0xA0) {
		if (!(status & BIT7) || (status & BIT4))
			info->icount.rxabort++;
		else if (status & BIT6)
			info->icount.rxover++;
		else if (!(status & BIT5)) {
			info->icount.rxcrc++;
			if (info->params.crc_type & HDLC_CRC_RETURN_EX)
				return_frame = 1;
		}
		framesize = 0;
#ifdef CONFIG_HDLC
		{
			struct net_device_stats *stats = hdlc_stats(info->netdev);
			stats->rx_errors++;
			stats->rx_frame_errors++;
		}
#endif
	} else
		return_frame = 1;

	if (return_frame)
		framesize = buf->count;

	if (debug_level >= DEBUG_LEVEL_BH)
		printk("%s(%d):rx_get_frame(%s) status=%04X size=%d\n",
			__FILE__,__LINE__,info->device_name,status,framesize);
			
	if (debug_level >= DEBUG_LEVEL_DATA)
		trace_block(info, buf->data, framesize, 0);	
		
	if (framesize) {
		if ((info->params.crc_type & HDLC_CRC_RETURN_EX &&
		      framesize+1 > info->max_frame_size) ||
		    framesize > info->max_frame_size)
			info->icount.rxlong++;
		else {
			if (status & BIT5)
				info->icount.rxok++;

			if (info->params.crc_type & HDLC_CRC_RETURN_EX) {
				*(buf->data + framesize) = status & BIT5 ? RX_OK:RX_CRC_ERROR;
				++framesize;
			}

#ifdef CONFIG_HDLC
			if (info->netcount)
				hdlcdev_rx(info, buf->data, framesize);
			else
#endif
				ldisc_receive_buf(tty, buf->data, info->flag_buf, framesize);
		}
	}

	spin_lock_irqsave(&info->lock,flags);
	buf->status = buf->count = 0;
	info->rx_frame_count--;
	info->rx_get++;
	if (info->rx_get >= info->rx_buf_count)
		info->rx_get = 0;
	spin_unlock_irqrestore(&info->lock,flags);

	return 1;
}

static BOOLEAN register_test(MGSLPC_INFO *info)
{
	static unsigned char patterns[] = 
	    { 0x00, 0xff, 0xaa, 0x55, 0x69, 0x96, 0x0f };
	static unsigned int count = ARRAY_SIZE(patterns);
	unsigned int i;
	BOOLEAN rc = TRUE;
	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
	reset_device(info);

	for (i = 0; i < count; i++) {
		write_reg(info, XAD1, patterns[i]);
		write_reg(info, XAD2, patterns[(i + 1) % count]);
		if ((read_reg(info, XAD1) != patterns[i]) ||
		    (read_reg(info, XAD2) != patterns[(i + 1) % count])) {
			rc = FALSE;
			break;
		}
	}

	spin_unlock_irqrestore(&info->lock,flags);
	return rc;
}

static BOOLEAN irq_test(MGSLPC_INFO *info)
{
	unsigned long end_time;
	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
	reset_device(info);

	info->testing_irq = TRUE;
	hdlc_mode(info);

	info->irq_occurred = FALSE;

	/* init hdlc mode */

	irq_enable(info, CHA, IRQ_TIMER);
	write_reg(info, CHA + TIMR, 0);	/* 512 cycles */
	issue_command(info, CHA, CMD_START_TIMER);

	spin_unlock_irqrestore(&info->lock,flags);

	end_time=100;
	while(end_time-- && !info->irq_occurred) {
		msleep_interruptible(10);
	}
	
	info->testing_irq = FALSE;

	spin_lock_irqsave(&info->lock,flags);
	reset_device(info);
	spin_unlock_irqrestore(&info->lock,flags);
	
	return info->irq_occurred ? TRUE : FALSE;
}

static int adapter_test(MGSLPC_INFO *info)
{
	if (!register_test(info)) {
		info->init_error = DiagStatus_AddressFailure;
		printk( "%s(%d):Register test failure for device %s Addr=%04X\n",
			__FILE__,__LINE__,info->device_name, (unsigned short)(info->io_base) );
		return -ENODEV;
	}

	if (!irq_test(info)) {
		info->init_error = DiagStatus_IrqFailure;
		printk( "%s(%d):Interrupt test failure for device %s IRQ=%d\n",
			__FILE__,__LINE__,info->device_name, (unsigned short)(info->irq_level) );
		return -ENODEV;
	}

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):device %s passed diagnostics\n",
			__FILE__,__LINE__,info->device_name);
	return 0;
}

static void trace_block(MGSLPC_INFO *info,const char* data, int count, int xmit)
{
	int i;
	int linecount;
	if (xmit)
		printk("%s tx data:\n",info->device_name);
	else
		printk("%s rx data:\n",info->device_name);
		
	while(count) {
		if (count > 16)
			linecount = 16;
		else
			linecount = count;
			
		for(i=0;i<linecount;i++)
			printk("%02X ",(unsigned char)data[i]);
		for(;i<17;i++)
			printk("   ");
		for(i=0;i<linecount;i++) {
			if (data[i]>=040 && data[i]<=0176)
				printk("%c",data[i]);
			else
				printk(".");
		}
		printk("\n");
		
		data  += linecount;
		count -= linecount;
	}
}

/* HDLC frame time out
 * update stats and do tx completion processing
 */
static void tx_timeout(unsigned long context)
{
	MGSLPC_INFO *info = (MGSLPC_INFO*)context;
	unsigned long flags;
	
	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk( "%s(%d):tx_timeout(%s)\n",
			__FILE__,__LINE__,info->device_name);
	if(info->tx_active &&
	   info->params.mode == MGSL_MODE_HDLC) {
		info->icount.txtimeout++;
	}
	spin_lock_irqsave(&info->lock,flags);
	info->tx_active = 0;
	info->tx_count = info->tx_put = info->tx_get = 0;

	spin_unlock_irqrestore(&info->lock,flags);
	
#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlcdev_tx_done(info);
	else
#endif
		bh_transmit(info);
}

#ifdef CONFIG_HDLC

/**
 * called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
 * set encoding and frame check sequence (FCS) options
 *
 * dev       pointer to network device structure
 * encoding  serial encoding setting
 * parity    FCS setting
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
			  unsigned short parity)
{
	MGSLPC_INFO *info = dev_to_port(dev);
	unsigned char  new_encoding;
	unsigned short new_crctype;

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	switch (encoding)
	{
	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
	default: return -EINVAL;
	}

	switch (parity)
	{
	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
	default: return -EINVAL;
	}

	info->params.encoding = new_encoding;
	info->params.crc_type = new_crctype;

	/* if network interface up, reprogram hardware */
	if (info->netcount)
		mgslpc_program_hw(info);

	return 0;
}

/**
 * called by generic HDLC layer to send frame
 *
 * skb  socket buffer containing HDLC frame
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	MGSLPC_INFO *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk(KERN_INFO "%s:hdlc_xmit(%s)\n",__FILE__,dev->name);

	/* stop sending until this frame completes */
	netif_stop_queue(dev);

	/* copy data to device buffers */
	memcpy(info->tx_buf, skb->data, skb->len);
	info->tx_get = 0;
	info->tx_put = info->tx_count = skb->len;

	/* update network statistics */
	stats->tx_packets++;
	stats->tx_bytes += skb->len;

	/* done with socket buffer, so free it */
	dev_kfree_skb(skb);

	/* save start time for transmit timeout detection */
	dev->trans_start = jiffies;

	/* start hardware transmitter if necessary */
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_active)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/**
 * called by network layer when interface enabled
 * claim resources and initialize hardware
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_open(struct net_device *dev)
{
	MGSLPC_INFO *info = dev_to_port(dev);
	int rc;
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s:hdlcdev_open(%s)\n",__FILE__,dev->name);

	/* generic HDLC layer open processing */
	if ((rc = hdlc_open(dev)))
		return rc;

	/* arbitrate between network and tty opens */
	spin_lock_irqsave(&info->netlock, flags);
	if (info->count != 0 || info->netcount != 0) {
		printk(KERN_WARNING "%s: hdlc_open returning busy\n", dev->name);
		spin_unlock_irqrestore(&info->netlock, flags);
		return -EBUSY;
	}
	info->netcount=1;
	spin_unlock_irqrestore(&info->netlock, flags);

	/* claim resources and init adapter */
	if ((rc = startup(info)) != 0) {
		spin_lock_irqsave(&info->netlock, flags);
		info->netcount=0;
		spin_unlock_irqrestore(&info->netlock, flags);
		return rc;
	}

	/* assert DTR and RTS, apply hardware settings */
	info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
	mgslpc_program_hw(info);

	/* enable network layer transmit */
	dev->trans_start = jiffies;
	netif_start_queue(dev);

	/* inform generic HDLC layer of current DCD status */
	spin_lock_irqsave(&info->lock, flags);
	get_signals(info);
	spin_unlock_irqrestore(&info->lock, flags);
	if (info->serial_signals & SerialSignal_DCD)
		netif_carrier_on(dev);
	else
		netif_carrier_off(dev);
	return 0;
}

/**
 * called by network layer when interface is disabled
 * shutdown hardware and release resources
 *
 * dev  pointer to network device structure
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_close(struct net_device *dev)
{
	MGSLPC_INFO *info = dev_to_port(dev);
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s:hdlcdev_close(%s)\n",__FILE__,dev->name);

	netif_stop_queue(dev);

	/* shutdown adapter and release resources */
	shutdown(info);

	hdlc_close(dev);

	spin_lock_irqsave(&info->netlock, flags);
	info->netcount=0;
	spin_unlock_irqrestore(&info->netlock, flags);

	return 0;
}

/**
 * called by network layer to process IOCTL call to network device
 *
 * dev  pointer to network device structure
 * ifr  pointer to network interface request structure
 * cmd  IOCTL command code
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings new_line;
	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
	MGSLPC_INFO *info = dev_to_port(dev);
	unsigned int flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s:hdlcdev_ioctl(%s)\n",__FILE__,dev->name);

	/* return error if TTY interface open */
	if (info->count)
		return -EBUSY;

	if (cmd != SIOCWANDEV)
		return hdlc_ioctl(dev, ifr, cmd);

	switch(ifr->ifr_settings.type) {
	case IF_GET_IFACE: /* return current sync_serial_settings */

		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}

		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);

		switch (flags){
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
		default: new_line.clock_type = CLOCK_DEFAULT;
		}

		new_line.clock_rate = info->params.clock_speed;
		new_line.loopback   = info->params.loopback ? 1:0;

		if (copy_to_user(line, &new_line, size))
			return -EFAULT;
		return 0;

	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */

		if(!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (copy_from_user(&new_line, line, size))
			return -EFAULT;

		switch (new_line.clock_type)
		{
		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
		case CLOCK_DEFAULT:  flags = info->params.flags &
					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
		default: return -EINVAL;
		}

		if (new_line.loopback != 0 && new_line.loopback != 1)
			return -EINVAL;

		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
		info->params.flags |= flags;

		info->params.loopback = new_line.loopback;

		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
			info->params.clock_speed = new_line.clock_rate;
		else
			info->params.clock_speed = 0;

		/* if network interface up, reprogram hardware */
		if (info->netcount)
			mgslpc_program_hw(info);
		return 0;

	default:
		return hdlc_ioctl(dev, ifr, cmd);
	}
}

/**
 * called by network layer when transmit timeout is detected
 *
 * dev  pointer to network device structure
 */
static void hdlcdev_tx_timeout(struct net_device *dev)
{
	MGSLPC_INFO *info = dev_to_port(dev);
	struct net_device_stats *stats = hdlc_stats(dev);
	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("hdlcdev_tx_timeout(%s)\n",dev->name);

	stats->tx_errors++;
	stats->tx_aborted_errors++;

	spin_lock_irqsave(&info->lock,flags);
	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);

	netif_wake_queue(dev);
}

/**
 * called by device driver when transmit completes
 * reenable network layer transmit if stopped
 *
 * info  pointer to device instance information
 */
static void hdlcdev_tx_done(MGSLPC_INFO *info)
{
	if (netif_queue_stopped(info->netdev))
		netif_wake_queue(info->netdev);
}

/**
 * called by device driver when frame received
 * pass frame to network layer
 *
 * info  pointer to device instance information
 * buf   pointer to buffer contianing frame data
 * size  count of data bytes in buf
 */
static void hdlcdev_rx(MGSLPC_INFO *info, char *buf, int size)
{
	struct sk_buff *skb = dev_alloc_skb(size);
	struct net_device *dev = info->netdev;
	struct net_device_stats *stats = hdlc_stats(dev);

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("hdlcdev_rx(%s)\n",dev->name);

	if (skb == NULL) {
		printk(KERN_NOTICE "%s: can't alloc skb, dropping packet\n", dev->name);
		stats->rx_dropped++;
		return;
	}

	memcpy(skb_put(skb, size),buf,size);

	skb->protocol = hdlc_type_trans(skb, info->netdev);

	stats->rx_packets++;
	stats->rx_bytes += size;

	netif_rx(skb);

	info->netdev->last_rx = jiffies;
}

/**
 * called by device driver when adding device instance
 * do generic HDLC initialization
 *
 * info  pointer to device instance information
 *
 * returns 0 if success, otherwise error code
 */
static int hdlcdev_init(MGSLPC_INFO *info)
{
	int rc;
	struct net_device *dev;
	hdlc_device *hdlc;

	/* allocate and initialize network and HDLC layer objects */

	if (!(dev = alloc_hdlcdev(info))) {
		printk(KERN_ERR "%s:hdlc device allocation failure\n",__FILE__);
		return -ENOMEM;
	}

	/* for network layer reporting purposes only */
	dev->base_addr = info->io_base;
	dev->irq       = info->irq_level;

	/* network layer callbacks and settings */
	dev->do_ioctl       = hdlcdev_ioctl;
	dev->open           = hdlcdev_open;
	dev->stop           = hdlcdev_close;
	dev->tx_timeout     = hdlcdev_tx_timeout;
	dev->watchdog_timeo = 10*HZ;
	dev->tx_queue_len   = 50;

	/* generic HDLC layer callbacks and settings */
	hdlc         = dev_to_hdlc(dev);
	hdlc->attach = hdlcdev_attach;
	hdlc->xmit   = hdlcdev_xmit;

	/* register objects with HDLC layer */
	if ((rc = register_hdlc_device(dev))) {
		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
		free_netdev(dev);
		return rc;
	}

	info->netdev = dev;
	return 0;
}

/**
 * called by device driver when removing device instance
 * do generic HDLC cleanup
 *
 * info  pointer to device instance information
 */
static void hdlcdev_exit(MGSLPC_INFO *info)
{
	unregister_hdlc_device(info->netdev);
	free_netdev(info->netdev);
	info->netdev = NULL;
}

#endif /* CONFIG_HDLC */