summaryrefslogblamecommitdiff
path: root/drivers/sbus/char/envctrl.c
blob: 19e8eddf887a8538325307d135d38883d3dbb08c (plain) (tree)
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656




















                                                                             
                           
                 
 


                         
                          












                             






































































































































































































































































































































































































































































































































































































































                                                                                            

                                                                     

























































                                                                        







                                                






























































































































































































































































































                                                                                                            
                                                         
 

                                                                     
                                                    
 


                                          




















                                                                                                        











































































                                                                                                          

                                                                   
                                              
                                    
         






                                      


                                                 
                   





                                        
                                     



                                      

                                                 




                             
/* $Id: envctrl.c,v 1.25 2002/01/15 09:01:26 davem Exp $
 * envctrl.c: Temperature and Fan monitoring on Machines providing it.
 *
 * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
 * Copyright (C) 2000  Vinh Truong    (vinh.truong@eng.sun.com)
 * VT - The implementation is to support Sun Microelectronics (SME) platform
 *      environment monitoring.  SME platforms use pcf8584 as the i2c bus 
 *      controller to access pcf8591 (8-bit A/D and D/A converter) and 
 *      pcf8571 (256 x 8-bit static low-voltage RAM with I2C-bus interface).
 *      At board level, it follows SME Firmware I2C Specification. Reference:
 * 	http://www-eu2.semiconductors.com/pip/PCF8584P
 * 	http://www-eu2.semiconductors.com/pip/PCF8574AP
 * 	http://www-eu2.semiconductors.com/pip/PCF8591P
 *
 * EB - Added support for CP1500 Global Address and PS/Voltage monitoring.
 * 		Eric Brower <ebrower@usa.net>
 *
 * DB - Audit every copy_to_user in envctrl_read.
 *              Daniele Bellucci <bellucda@tiscali.it>
 */

#define __KERNEL_SYSCALLS__
static int errno;

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/kernel.h>

#include <asm/ebus.h>
#include <asm/uaccess.h>
#include <asm/envctrl.h>

#define ENVCTRL_MINOR	162

#define PCF8584_ADDRESS	0x55

#define CONTROL_PIN	0x80
#define CONTROL_ES0	0x40
#define CONTROL_ES1	0x20
#define CONTROL_ES2	0x10
#define CONTROL_ENI	0x08
#define CONTROL_STA	0x04
#define CONTROL_STO	0x02
#define CONTROL_ACK	0x01

#define STATUS_PIN	0x80
#define STATUS_STS	0x20
#define STATUS_BER	0x10
#define STATUS_LRB	0x08
#define STATUS_AD0	0x08
#define STATUS_AAB	0x04
#define STATUS_LAB	0x02
#define STATUS_BB	0x01

/*
 * CLK Mode Register.
 */
#define BUS_CLK_90	0x00
#define BUS_CLK_45	0x01
#define BUS_CLK_11	0x02
#define BUS_CLK_1_5	0x03

#define CLK_3		0x00
#define CLK_4_43	0x10
#define CLK_6		0x14
#define CLK_8		0x18
#define CLK_12		0x1c

#define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
#define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */

/* Monitor type of i2c child device.
 * Firmware definitions.
 */
#define PCF8584_MAX_CHANNELS            8
#define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
#define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
#define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
#define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/

/* Monitor type of i2c child device.
 * Driver definitions.
 */
#define ENVCTRL_NOMON				0
#define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
#define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
#define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
#define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
					     /* monitor                     */
#define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
#define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
#define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
#define ENVCTRL_GLOBALADDR_MON		8    /* global address */

/* Child device type.
 * Driver definitions.
 */
#define I2C_ADC				0    /* pcf8591 */
#define I2C_GPIO			1    /* pcf8571 */

/* Data read from child device may need to decode
 * through a data table and a scale.
 * Translation type as defined by firmware.
 */
#define ENVCTRL_TRANSLATE_NO		0
#define ENVCTRL_TRANSLATE_PARTIAL	1
#define ENVCTRL_TRANSLATE_COMBINED	2
#define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
#define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */

/* Driver miscellaneous definitions. */
#define ENVCTRL_MAX_CPU			4
#define CHANNEL_DESC_SZ			256

/* Mask values for combined GlobalAddress/PowerStatus node */
#define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
#define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60

/* Node 0x70 ignored on CompactPCI CP1400/1500 platforms 
 * (see envctrl_init_i2c_child)
 */
#define ENVCTRL_CPCI_IGNORED_NODE		0x70

#define PCF8584_DATA	0x00
#define PCF8584_CSR	0x01

/* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
 * Property of a port or channel as defined by the firmware.
 */
struct pcf8584_channel {
        unsigned char chnl_no;
        unsigned char io_direction;
        unsigned char type;
        unsigned char last;
};

/* Each child device may have one or more tables of bytes to help decode
 * data. Table property as defined by the firmware.
 */ 
struct pcf8584_tblprop {
        unsigned int type;
        unsigned int scale;  
        unsigned int offset; /* offset from the beginning of the table */
        unsigned int size;
};

/* i2c child */
struct i2c_child_t {
	/* Either ADC or GPIO. */
	unsigned char i2ctype;
        unsigned long addr;    
        struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];

	/* Channel info. */ 
	unsigned int total_chnls;	/* Number of monitor channels. */
	unsigned char fan_mask;		/* Byte mask for fan status channels. */
	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
        struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];

	/* Properties of all monitor channels. */
	unsigned int total_tbls;	/* Number of monitor tables. */
        char *tables;			/* Pointer to table(s). */
	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
	char mon_type[PCF8584_MAX_CHANNELS];
};

static void __iomem *i2c;
static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
static unsigned int warning_temperature = 0;
static unsigned int shutdown_temperature = 0;
static char read_cpu;

/* Forward declarations. */
static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);

/* Function Description: Test the PIN bit (Pending Interrupt Not) 
 * 			 to test when serial transmission is completed .
 * Return : None.
 */
static void envtrl_i2c_test_pin(void)
{
	int limit = 1000000;

	while (--limit > 0) {
		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN)) 
			break;
		udelay(1);
	} 

	if (limit <= 0)
		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
}

/* Function Description: Test busy bit.
 * Return : None.
 */
static void envctrl_i2c_test_bb(void)
{
	int limit = 1000000;

	while (--limit > 0) {
		/* Busy bit 0 means busy. */
		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
			break;
		udelay(1);
	} 

	if (limit <= 0)
		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
}

/* Function Description: Send the address for a read access.
 * Return : 0 if not acknowledged, otherwise acknowledged.
 */
static int envctrl_i2c_read_addr(unsigned char addr)
{
	envctrl_i2c_test_bb();

	/* Load address. */
	writeb(addr + 1, i2c + PCF8584_DATA);

	envctrl_i2c_test_bb();

	writeb(OBD_SEND_START, i2c + PCF8584_CSR);

	/* Wait for PIN. */
	envtrl_i2c_test_pin();

	/* CSR 0 means acknowledged. */
	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
		return readb(i2c + PCF8584_DATA);
	} else {
		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
		return 0;
	}
}

/* Function Description: Send the address for write mode.  
 * Return : None.
 */
static void envctrl_i2c_write_addr(unsigned char addr)
{
	envctrl_i2c_test_bb();
	writeb(addr, i2c + PCF8584_DATA);

	/* Generate Start condition. */
	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
}

/* Function Description: Read 1 byte of data from addr 
 *			 set by envctrl_i2c_read_addr() 
 * Return : Data from address set by envctrl_i2c_read_addr().
 */
static unsigned char envctrl_i2c_read_data(void)
{
	envtrl_i2c_test_pin();
	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
	return readb(i2c + PCF8584_DATA);
}

/* Function Description: Instruct the device which port to read data from.  
 * Return : None.
 */
static void envctrl_i2c_write_data(unsigned char port)
{
	envtrl_i2c_test_pin();
	writeb(port, i2c + PCF8584_DATA);
}

/* Function Description: Generate Stop condition after last byte is sent.
 * Return : None.
 */
static void envctrl_i2c_stop(void)
{
	envtrl_i2c_test_pin();
	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
}

/* Function Description: Read adc device.
 * Return : Data at address and port.
 */
static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
{
	/* Send address. */
	envctrl_i2c_write_addr(addr);

	/* Setup port to read. */
	envctrl_i2c_write_data(port);
	envctrl_i2c_stop();

	/* Read port. */
	envctrl_i2c_read_addr(addr);

	/* Do a single byte read and send stop. */
	envctrl_i2c_read_data();
	envctrl_i2c_stop();

	return readb(i2c + PCF8584_DATA);
}

/* Function Description: Read gpio device.
 * Return : Data at address.
 */
static unsigned char envctrl_i2c_read_8574(unsigned char addr)
{
	unsigned char rd;

	envctrl_i2c_read_addr(addr);

	/* Do a single byte read and send stop. */
	rd = envctrl_i2c_read_data();
	envctrl_i2c_stop();
	return rd;
}

/* Function Description: Decode data read from an adc device using firmware
 *                       table.
 * Return: Number of read bytes. Data is stored in bufdata in ascii format.
 */
static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
				      int scale, char *tbl, char *bufdata)
{
	int len = 0;

	switch (translate_type) {
	case ENVCTRL_TRANSLATE_NO:
		/* No decode necessary. */
		len = 1;
		bufdata[0] = data;
		break;

	case ENVCTRL_TRANSLATE_FULL:
		/* Decode this way: data = table[data]. */
		len = 1;
		bufdata[0] = tbl[data];
		break;

	case ENVCTRL_TRANSLATE_SCALE:
		/* Decode this way: data = table[data]/scale */
		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
		len = strlen(bufdata);
		bufdata[len - 1] = bufdata[len - 2];
		bufdata[len - 2] = '.';
		break;

	default:
		break;
	};

	return len;
}

/* Function Description: Read cpu-related data such as cpu temperature, voltage.
 * Return: Number of read bytes. Data is stored in bufdata in ascii format.
 */
static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
				 char mon_type, unsigned char *bufdata)
{
	unsigned char data;
	int i;
	char *tbl, j = -1;

	/* Find the right monitor type and channel. */
	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
		if (pchild->mon_type[i] == mon_type) {
			if (++j == cpu) {
				break;
			}
		}
	}

	if (j != cpu)
		return 0;

        /* Read data from address and port. */
	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
				     (unsigned char)pchild->chnl_array[i].chnl_no);

	/* Find decoding table. */
	tbl = pchild->tables + pchild->tblprop_array[i].offset;

	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
					  pchild->tblprop_array[i].scale,
					  tbl, bufdata);
}

/* Function Description: Read noncpu-related data such as motherboard 
 *                       temperature.
 * Return: Number of read bytes. Data is stored in bufdata in ascii format.
 */
static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
				    char mon_type, unsigned char *bufdata)
{
	unsigned char data;
	int i;
	char *tbl = NULL;

	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
		if (pchild->mon_type[i] == mon_type)
			break;
	}

	if (i >= PCF8584_MAX_CHANNELS)
		return 0;

        /* Read data from address and port. */
	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
				     (unsigned char)pchild->chnl_array[i].chnl_no);

	/* Find decoding table. */
	tbl = pchild->tables + pchild->tblprop_array[i].offset;

	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
					  pchild->tblprop_array[i].scale,
					  tbl, bufdata);
}

/* Function Description: Read fan status.
 * Return : Always 1 byte. Status stored in bufdata.
 */
static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
				  unsigned char data,
				  char *bufdata)
{
	unsigned char tmp, ret = 0;
	int i, j = 0;

	tmp = data & pchild->fan_mask;

	if (tmp == pchild->fan_mask) {
		/* All bits are on. All fans are functioning. */
		ret = ENVCTRL_ALL_FANS_GOOD;
	} else if (tmp == 0) {
		/* No bits are on. No fans are functioning. */
		ret = ENVCTRL_ALL_FANS_BAD;
	} else {
		/* Go through all channels, mark 'on' the matched bits.
		 * Notice that fan_mask may have discontiguous bits but
		 * return mask are always contiguous. For example if we
		 * monitor 4 fans at channels 0,1,2,4, the return mask
		 * should be 00010000 if only fan at channel 4 is working.
		 */
		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
			if (pchild->fan_mask & chnls_mask[i]) {
				if (!(chnls_mask[i] & tmp))
					ret |= chnls_mask[j];

				j++;
			}
		}
	}

	bufdata[0] = ret;
	return 1;
}

/* Function Description: Read global addressing line.
 * Return : Always 1 byte. Status stored in bufdata.
 */
static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
				  unsigned char data,
				  char *bufdata)
{
	/* Translatation table is not necessary, as global
	 * addr is the integer value of the GA# bits.
	 *
	 * NOTE: MSB is documented as zero, but I see it as '1' always....
	 *
	 * -----------------------------------------------
	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
	 * -----------------------------------------------
	 * GA0 - GA4	integer value of Global Address (backplane slot#)
	 * DEG			0 = cPCI Power supply output is starting to degrade
	 * 				1 = cPCI Power supply output is OK
	 * FAL			0 = cPCI Power supply has failed
	 * 				1 = cPCI Power supply output is OK
	 */
	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
	return 1;
}

/* Function Description: Read standard voltage and power supply status.
 * Return : Always 1 byte. Status stored in bufdata.
 */
static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
						unsigned char data,
						char *bufdata)
{
	unsigned char tmp, ret = 0;
	int i, j = 0;

	tmp = data & pchild->voltage_mask;

	/* Two channels are used to monitor voltage and power supply. */
	if (tmp == pchild->voltage_mask) {
		/* All bits are on. Voltage and power supply are okay. */
		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
	} else if (tmp == 0) {
		/* All bits are off. Voltage and power supply are bad */
		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
	} else {
		/* Either voltage or power supply has problem. */
		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
			if (pchild->voltage_mask & chnls_mask[i]) {
				j++;

				/* Break out when there is a mismatch. */
				if (!(chnls_mask[i] & tmp))
					break; 
			}
		}

		/* Make a wish that hardware will always use the
		 * first channel for voltage and the second for
		 * power supply.
		 */
		if (j == 1)
			ret = ENVCTRL_VOLTAGE_BAD;
		else
			ret = ENVCTRL_POWERSUPPLY_BAD;
	}

	bufdata[0] = ret;
	return 1;
}

/* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
 * Return: Number of read bytes. 0 for error.
 */
static ssize_t
envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	struct i2c_child_t *pchild;
	unsigned char data[10];
	int ret = 0;

	/* Get the type of read as decided in ioctl() call.
	 * Find the appropriate i2c child.
	 * Get the data and put back to the user buffer.
	 */

	switch ((int)(long)file->private_data) {
	case ENVCTRL_RD_WARNING_TEMPERATURE:
		if (warning_temperature == 0)
			return 0;

		data[0] = (unsigned char)(warning_temperature);
		ret = 1;
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
		if (shutdown_temperature == 0)
			return 0;

		data[0] = (unsigned char)(shutdown_temperature);
		ret = 1;
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
			return 0;
		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_CPU_TEMPERATURE:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
			return 0;
		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);

		/* Reset cpu to the default cpu0. */
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_CPU_VOLTAGE:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
			return 0;
		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);

		/* Reset cpu to the default cpu0. */
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_SCSI_TEMPERATURE:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
			return 0;
		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
			return 0;
		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_FAN_STATUS:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
			return 0;
		data[0] = envctrl_i2c_read_8574(pchild->addr);
		ret = envctrl_i2c_fan_status(pchild,data[0], data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;
	
	case ENVCTRL_RD_GLOBALADDRESS:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
			return 0;
		data[0] = envctrl_i2c_read_8574(pchild->addr);
		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	case ENVCTRL_RD_VOLTAGE_STATUS:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
			/* If voltage monitor not present, check for CPCI equivalent */
			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
				return 0;
		data[0] = envctrl_i2c_read_8574(pchild->addr);
		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
		if (copy_to_user(buf, data, ret))
			ret = -EFAULT;
		break;

	default:
		break;

	};

	return ret;
}

/* Function Description: Command what to read.  Mapped to user ioctl().
 * Return: Gives 0 for implemented commands, -EINVAL otherwise.
 */
static long
envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	char __user *infobuf;

	switch (cmd) {
	case ENVCTRL_RD_WARNING_TEMPERATURE:
	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
	case ENVCTRL_RD_FAN_STATUS:
	case ENVCTRL_RD_VOLTAGE_STATUS:
	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
	case ENVCTRL_RD_SCSI_TEMPERATURE:
	case ENVCTRL_RD_GLOBALADDRESS:
		file->private_data = (void *)(long)cmd;
		break;

	case ENVCTRL_RD_CPU_TEMPERATURE:
	case ENVCTRL_RD_CPU_VOLTAGE:
		/* Check to see if application passes in any cpu number,
		 * the default is cpu0.
		 */
		infobuf = (char __user *) arg;
		if (infobuf == NULL) {
			read_cpu = 0;
		}else {
			get_user(read_cpu, infobuf);
		}

		/* Save the command for use when reading. */
		file->private_data = (void *)(long)cmd;
		break;

	default:
		return -EINVAL;
	};

	return 0;
}

/* Function Description: open device. Mapped to user open().
 * Return: Always 0.
 */
static int
envctrl_open(struct inode *inode, struct file *file)
{
	file->private_data = NULL;
	return 0;
}

/* Function Description: Open device. Mapped to user close().
 * Return: Always 0.
 */
static int
envctrl_release(struct inode *inode, struct file *file)
{
	return 0;
}

static struct file_operations envctrl_fops = {
	.owner =		THIS_MODULE,
	.read =			envctrl_read,
	.unlocked_ioctl =	envctrl_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl =		envctrl_ioctl,
#endif
	.open =			envctrl_open,
	.release =		envctrl_release,
};	

static struct miscdevice envctrl_dev = {
	ENVCTRL_MINOR,
	"envctrl",
	&envctrl_fops
};

/* Function Description: Set monitor type based on firmware description.
 * Return: None.
 */
static void envctrl_set_mon(struct i2c_child_t *pchild,
			    char *chnl_desc,
			    int chnl_no)
{
	/* Firmware only has temperature type.  It does not distinguish
	 * different kinds of temperatures.  We use channel description
	 * to disinguish them.
	 */
	if (!(strcmp(chnl_desc,"temp,cpu")) ||
	    !(strcmp(chnl_desc,"temp,cpu0")) ||
	    !(strcmp(chnl_desc,"temp,cpu1")) ||
	    !(strcmp(chnl_desc,"temp,cpu2")) ||
	    !(strcmp(chnl_desc,"temp,cpu3")))
		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;

	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
	    !(strcmp(chnl_desc,"vddcore,cpu3")))
		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;

	if (!(strcmp(chnl_desc,"temp,motherboard")))
		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;

	if (!(strcmp(chnl_desc,"temp,scsi")))
		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;

	if (!(strcmp(chnl_desc,"temp,ethernet")))
		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
}

/* Function Description: Initialize monitor channel with channel desc,
 *                       decoding tables, monitor type, optional properties.
 * Return: None.
 */
static void envctrl_init_adc(struct i2c_child_t *pchild, int node)
{
	char chnls_desc[CHANNEL_DESC_SZ];
	int i = 0, len;
	char *pos = chnls_desc;

	/* Firmware describe channels into a stream separated by a '\0'. */
	len = prom_getproperty(node, "channels-description", chnls_desc,
			       CHANNEL_DESC_SZ);
	chnls_desc[CHANNEL_DESC_SZ - 1] = '\0';

	while (len > 0) {
		int l = strlen(pos) + 1;
		envctrl_set_mon(pchild, pos, i++);
		len -= l;
		pos += l;
	}

	/* Get optional properties. */
        len = prom_getproperty(node, "warning-temp", (char *)&warning_temperature,
			       sizeof(warning_temperature));
        len = prom_getproperty(node, "shutdown-temp", (char *)&shutdown_temperature,
			       sizeof(shutdown_temperature));
}

/* Function Description: Initialize child device monitoring fan status.
 * Return: None.
 */
static void envctrl_init_fanstat(struct i2c_child_t *pchild)
{
	int i;

	/* Go through all channels and set up the mask. */
	for (i = 0; i < pchild->total_chnls; i++)
		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];

	/* We only need to know if this child has fan status monitored.
	 * We don't care which channels since we have the mask already.
	 */
	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
}

/* Function Description: Initialize child device for global addressing line.
 * Return: None.
 */
static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
{
	int i;

	/* Voltage/PowerSupply monitoring is piggybacked 
	 * with Global Address on CompactPCI.  See comments
	 * within envctrl_i2c_globaladdr for bit assignments.
	 *
	 * The mask is created here by assigning mask bits to each
	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
	 * Channel numbers are not consecutive within the globaladdr
	 * node (why?), so we use the actual counter value as chnls_mask
	 * index instead of the chnl_array[x].chnl_no value.
	 *
	 * NOTE: This loop could be replaced with a constant representing
	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
	 */
	for (i = 0; i < pchild->total_chnls; i++) {
		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
			pchild->voltage_mask |= chnls_mask[i];
		}
	}

	/* We only need to know if this child has global addressing 
	 * line monitored.  We don't care which channels since we know 
	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
	 */
	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
}

/* Initialize child device monitoring voltage status. */
static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
{
	int i;

	/* Go through all channels and set up the mask. */
	for (i = 0; i < pchild->total_chnls; i++)
		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];

	/* We only need to know if this child has voltage status monitored.
	 * We don't care which channels since we have the mask already.
	 */
	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
}

/* Function Description: Initialize i2c child device.
 * Return: None.
 */
static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
				   struct i2c_child_t *pchild)
{
	int node, len, i, tbls_size = 0;

	node = edev_child->prom_node;

	/* Get device address. */
	len = prom_getproperty(node, "reg",
			       (char *) &(pchild->addr),
			       sizeof(pchild->addr));

	/* Get tables property.  Read firmware temperature tables. */
	len = prom_getproperty(node, "translation",
			       (char *) pchild->tblprop_array,
			       (PCF8584_MAX_CHANNELS *
				sizeof(struct pcf8584_tblprop)));
	if (len > 0) {
                pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
		for (i = 0; i < pchild->total_tbls; i++) {
			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
			}
		}

                pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
		if (pchild->tables == NULL){
			printk("envctrl: Failed to allocate table.\n");
			return;
		}
                len = prom_getproperty(node, "tables",
				       (char *) pchild->tables, tbls_size);
                if (len <= 0) {
			printk("envctrl: Failed to get table.\n");
			return;
		}
	}

	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
	 * "For Factory Use Only."
	 *
	 * We ignore the node on these platforms by assigning the
	 * 'NULL' monitor type.
	 */
	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
		int len;
		char prop[56];

		len = prom_getproperty(prom_root_node, "name", prop, sizeof(prop));
		if (0 < len && (0 == strncmp(prop, "SUNW,UltraSPARC-IIi-cEngine", len)))
		{
			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
				pchild->mon_type[len] = ENVCTRL_NOMON;
			}
			return;
		}
	}

	/* Get the monitor channels. */
	len = prom_getproperty(node, "channels-in-use",
			       (char *) pchild->chnl_array,
			       (PCF8584_MAX_CHANNELS *
				sizeof(struct pcf8584_channel)));
	pchild->total_chnls = len / sizeof(struct pcf8584_channel);

	for (i = 0; i < pchild->total_chnls; i++) {
		switch (pchild->chnl_array[i].type) {
		case PCF8584_TEMP_TYPE:
			envctrl_init_adc(pchild, node);
			break;

		case PCF8584_GLOBALADDR_TYPE:
			envctrl_init_globaladdr(pchild);
			i = pchild->total_chnls;
			break;

		case PCF8584_FANSTAT_TYPE:
			envctrl_init_fanstat(pchild);
			i = pchild->total_chnls;
			break;

		case PCF8584_VOLTAGE_TYPE:
			if (pchild->i2ctype == I2C_ADC) {
				envctrl_init_adc(pchild,node);
			} else {
				envctrl_init_voltage_status(pchild);
			}
			i = pchild->total_chnls;
			break;

		default:
			break;
		};
	}
}

/* Function Description: Search the child device list for a device.
 * Return : The i2c child if found. NULL otherwise.
 */
static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
{
	int i, j;

	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
			if (i2c_childlist[i].mon_type[j] == mon_type) {
				return (struct i2c_child_t *)(&(i2c_childlist[i]));
			}
		}
	}
	return NULL;
}

static void envctrl_do_shutdown(void)
{
	static int inprog = 0;
	static char *envp[] = {	
		"HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
	char *argv[] = { 
		"/sbin/shutdown", "-h", "now", NULL };	

	if (inprog != 0)
		return;

	inprog = 1;
	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
	if (0 > execve("/sbin/shutdown", argv, envp)) {
		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n"); 
		inprog = 0;  /* unlikely to succeed, but we could try again */
	}
}

static struct task_struct *kenvctrld_task;

static int kenvctrld(void *__unused)
{
	int poll_interval;
	int whichcpu;
	char tempbuf[10];
	struct i2c_child_t *cputemp;

	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
		printk(KERN_ERR 
		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
		return -ENODEV;
	}

	poll_interval = 5000; /* TODO env_mon_interval */

	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
	for (;;) {
		msleep_interruptible(poll_interval);

		if (kthread_should_stop())
			break;
		
		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
						      ENVCTRL_CPUTEMP_MON,
						      tempbuf)) {
				if (tempbuf[0] >= shutdown_temperature) {
					printk(KERN_CRIT 
						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
						"shutdown threshold %i C\n", 
						current->comm, whichcpu, 
						tempbuf[0], shutdown_temperature);
					envctrl_do_shutdown();
				}
			}
		}
	}
	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
	return 0;
}

static int __init envctrl_init(void)
{
	struct linux_ebus *ebus = NULL;
	struct linux_ebus_device *edev = NULL;
	struct linux_ebus_child *edev_child = NULL;
	int err, i = 0;

	for_each_ebus(ebus) {
		for_each_ebusdev(edev, ebus) {
			if (!strcmp(edev->prom_name, "bbc")) {
				/* If we find a boot-bus controller node,
				 * then this envctrl driver is not for us.
				 */
				return -ENODEV;
			}
		}
	}

	/* Traverse through ebus and ebus device list for i2c device and
	 * adc and gpio nodes.
	 */
	for_each_ebus(ebus) {
		for_each_ebusdev(edev, ebus) {
			if (!strcmp(edev->prom_name, "i2c")) {
				i2c = ioremap(edev->resource[0].start, 0x2);
				for_each_edevchild(edev, edev_child) {
					if (!strcmp("gpio", edev_child->prom_name)) {
						i2c_childlist[i].i2ctype = I2C_GPIO;
						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
					}
					if (!strcmp("adc", edev_child->prom_name)) {
						i2c_childlist[i].i2ctype = I2C_ADC;
						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
					}
				}
				goto done;
			}
		}
	}

done:
	if (!edev) {
		printk("envctrl: I2C device not found.\n");
		return -ENODEV;
	}

	/* Set device address. */
	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);

	/* Set system clock and SCL frequencies. */ 
	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);

	/* Enable serial interface. */
	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
	udelay(200);

	/* Register the device as a minor miscellaneous device. */
	err = misc_register(&envctrl_dev);
	if (err) {
		printk("envctrl: Unable to get misc minor %d\n",
		       envctrl_dev.minor);
		goto out_iounmap;
	}

	/* Note above traversal routine post-incremented 'i' to accommodate 
	 * a next child device, so we decrement before reverse-traversal of
	 * child devices.
	 */
	printk("envctrl: initialized ");
	for (--i; i >= 0; --i) {
		printk("[%s 0x%lx]%s", 
			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") : 
			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")), 
			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
	}

	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
	if (IS_ERR(kenvctrld_task)) {
		err = PTR_ERR(kenvctrld_task);
		goto out_deregister;
	}

	return 0;

out_deregister:
	misc_deregister(&envctrl_dev);
out_iounmap:
	iounmap(i2c);
	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
		kfree(i2c_childlist[i].tables);

	return err;
}

static void __exit envctrl_cleanup(void)
{
	int i;

	kthread_stop(kenvctrld_task);

	iounmap(i2c);
	misc_deregister(&envctrl_dev);

	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
		kfree(i2c_childlist[i].tables);
}

module_init(envctrl_init);
module_exit(envctrl_cleanup);
MODULE_LICENSE("GPL");