tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4573 insertions, 0 deletions

diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c
new file mode 100644
index 000000000000..bcc31f2140ac
--- /dev/null
+++ b/drivers/tty/serial/crisv10.c
@@ -0,0 +1,4573 @@
+/*
+ * Serial port driver for the ETRAX 100LX chip
+ *
+ *    Copyright (C) 1998-2007  Axis Communications AB
+ *
+ *    Many, many authors. Based once upon a time on serial.c for 16x50.
+ *
+ */
+
+static char *serial_version = "$Revision: 1.25 $";
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/bitops.h>
+#include <linux/seq_file.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <asm/dma.h>
+#include <asm/system.h>
+
+#include <arch/svinto.h>
+
+/* non-arch dependent serial structures are in linux/serial.h */
+#include <linux/serial.h>
+/* while we keep our own stuff (struct e100_serial) in a local .h file */
+#include "crisv10.h"
+#include <asm/fasttimer.h>
+#include <arch/io_interface_mux.h>
+
+#ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
+#ifndef CONFIG_ETRAX_FAST_TIMER
+#error "Enable FAST_TIMER to use SERIAL_FAST_TIMER"
+#endif
+#endif
+
+#if defined(CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS) && \
+           (CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS == 0)
+#error "RX_TIMEOUT_TICKS == 0 not allowed, use 1"
+#endif
+
+#if defined(CONFIG_ETRAX_RS485_ON_PA) && defined(CONFIG_ETRAX_RS485_ON_PORT_G)
+#error "Disable either CONFIG_ETRAX_RS485_ON_PA or CONFIG_ETRAX_RS485_ON_PORT_G"
+#endif
+
+/*
+ * All of the compatibilty code so we can compile serial.c against
+ * older kernels is hidden in serial_compat.h
+ */
+#if defined(LOCAL_HEADERS)
+#include "serial_compat.h"
+#endif
+
+struct tty_driver *serial_driver;
+
+/* number of characters left in xmit buffer before we ask for more */
+#define WAKEUP_CHARS 256
+
+//#define SERIAL_DEBUG_INTR
+//#define SERIAL_DEBUG_OPEN
+//#define SERIAL_DEBUG_FLOW
+//#define SERIAL_DEBUG_DATA
+//#define SERIAL_DEBUG_THROTTLE
+//#define SERIAL_DEBUG_IO  /* Debug for Extra control and status pins */
+//#define SERIAL_DEBUG_LINE 0 /* What serport we want to debug */
+
+/* Enable this to use serial interrupts to handle when you
+   expect the first received event on the serial port to
+   be an error, break or similar. Used to be able to flash IRMA
+   from eLinux */
+#define SERIAL_HANDLE_EARLY_ERRORS
+
+/* Currently 16 descriptors x 128 bytes = 2048 bytes */
+#define SERIAL_DESCR_BUF_SIZE 256
+
+#define SERIAL_PRESCALE_BASE 3125000 /* 3.125MHz */
+#define DEF_BAUD_BASE SERIAL_PRESCALE_BASE
+
+/* We don't want to load the system with massive fast timer interrupt
+ * on high baudrates so limit it to 250 us (4kHz) */
+#define MIN_FLUSH_TIME_USEC 250
+
+/* Add an x here to log a lot of timer stuff */
+#define TIMERD(x)
+/* Debug details of interrupt handling */
+#define DINTR1(x)  /* irq on/off, errors */
+#define DINTR2(x)    /* tx and rx */
+/* Debug flip buffer stuff */
+#define DFLIP(x)
+/* Debug flow control and overview of data flow */
+#define DFLOW(x)
+#define DBAUD(x)
+#define DLOG_INT_TRIG(x)
+
+//#define DEBUG_LOG_INCLUDED
+#ifndef DEBUG_LOG_INCLUDED
+#define DEBUG_LOG(line, string, value)
+#else
+struct debug_log_info
+{
+	unsigned long time;
+	unsigned long timer_data;
+//  int line;
+	const char *string;
+	int value;
+};
+#define DEBUG_LOG_SIZE 4096
+
+struct debug_log_info debug_log[DEBUG_LOG_SIZE];
+int debug_log_pos = 0;
+
+#define DEBUG_LOG(_line, _string, _value) do { \
+  if ((_line) == SERIAL_DEBUG_LINE) {\
+    debug_log_func(_line, _string, _value); \
+  }\
+}while(0)
+
+void debug_log_func(int line, const char *string, int value)
+{
+	if (debug_log_pos < DEBUG_LOG_SIZE) {
+		debug_log[debug_log_pos].time = jiffies;
+		debug_log[debug_log_pos].timer_data = *R_TIMER_DATA;
+//    debug_log[debug_log_pos].line = line;
+		debug_log[debug_log_pos].string = string;
+		debug_log[debug_log_pos].value = value;
+		debug_log_pos++;
+	}
+	/*printk(string, value);*/
+}
+#endif
+
+#ifndef CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS
+/* Default number of timer ticks before flushing rx fifo
+ * When using "little data, low latency applications: use 0
+ * When using "much data applications (PPP)" use ~5
+ */
+#define CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS 5
+#endif
+
+unsigned long timer_data_to_ns(unsigned long timer_data);
+
+static void change_speed(struct e100_serial *info);
+static void rs_throttle(struct tty_struct * tty);
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
+static int rs_write(struct tty_struct *tty,
+		const unsigned char *buf, int count);
+#ifdef CONFIG_ETRAX_RS485
+static int e100_write_rs485(struct tty_struct *tty,
+		const unsigned char *buf, int count);
+#endif
+static int get_lsr_info(struct e100_serial *info, unsigned int *value);
+
+
+#define DEF_BAUD 115200   /* 115.2 kbit/s */
+#define STD_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
+#define DEF_RX 0x20  /* or SERIAL_CTRL_W >> 8 */
+/* Default value of tx_ctrl register: has txd(bit 7)=1 (idle) as default */
+#define DEF_TX 0x80  /* or SERIAL_CTRL_B */
+
+/* offsets from R_SERIALx_CTRL */
+
+#define REG_DATA 0
+#define REG_DATA_STATUS32 0 /* this is the 32 bit register R_SERIALx_READ */
+#define REG_TR_DATA 0
+#define REG_STATUS 1
+#define REG_TR_CTRL 1
+#define REG_REC_CTRL 2
+#define REG_BAUD 3
+#define REG_XOFF 4  /* this is a 32 bit register */
+
+/* The bitfields are the same for all serial ports */
+#define SER_RXD_MASK         IO_MASK(R_SERIAL0_STATUS, rxd)
+#define SER_DATA_AVAIL_MASK  IO_MASK(R_SERIAL0_STATUS, data_avail)
+#define SER_FRAMING_ERR_MASK IO_MASK(R_SERIAL0_STATUS, framing_err)
+#define SER_PAR_ERR_MASK     IO_MASK(R_SERIAL0_STATUS, par_err)
+#define SER_OVERRUN_MASK     IO_MASK(R_SERIAL0_STATUS, overrun)
+
+#define SER_ERROR_MASK (SER_OVERRUN_MASK | SER_PAR_ERR_MASK | SER_FRAMING_ERR_MASK)
+
+/* Values for info->errorcode */
+#define ERRCODE_SET_BREAK    (TTY_BREAK)
+#define ERRCODE_INSERT        0x100
+#define ERRCODE_INSERT_BREAK (ERRCODE_INSERT | TTY_BREAK)
+
+#define FORCE_EOP(info)  *R_SET_EOP = 1U << info->iseteop;
+
+/*
+ * General note regarding the use of IO_* macros in this file:
+ *
+ * We will use the bits defined for DMA channel 6 when using various
+ * IO_* macros (e.g. IO_STATE, IO_MASK, IO_EXTRACT) and _assume_ they are
+ * the same for all channels (which of course they are).
+ *
+ * We will also use the bits defined for serial port 0 when writing commands
+ * to the different ports, as these bits too are the same for all ports.
+ */
+
+
+/* Mask for the irqs possibly enabled in R_IRQ_MASK1_RD etc. */
+static const unsigned long e100_ser_int_mask = 0
+#ifdef CONFIG_ETRAX_SERIAL_PORT0
+| IO_MASK(R_IRQ_MASK1_RD, ser0_data) | IO_MASK(R_IRQ_MASK1_RD, ser0_ready)
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT1
+| IO_MASK(R_IRQ_MASK1_RD, ser1_data) | IO_MASK(R_IRQ_MASK1_RD, ser1_ready)
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT2
+| IO_MASK(R_IRQ_MASK1_RD, ser2_data) | IO_MASK(R_IRQ_MASK1_RD, ser2_ready)
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT3
+| IO_MASK(R_IRQ_MASK1_RD, ser3_data) | IO_MASK(R_IRQ_MASK1_RD, ser3_ready)
+#endif
+;
+unsigned long r_alt_ser_baudrate_shadow = 0;
+
+/* this is the data for the four serial ports in the etrax100 */
+/*  DMA2(ser2), DMA4(ser3), DMA6(ser0) or DMA8(ser1) */
+/* R_DMA_CHx_CLR_INTR, R_DMA_CHx_FIRST, R_DMA_CHx_CMD */
+
+static struct e100_serial rs_table[] = {
+	{ .baud        = DEF_BAUD,
+	  .ioport        = (unsigned char *)R_SERIAL0_CTRL,
+	  .irq         = 1U << 12, /* uses DMA 6 and 7 */
+	  .oclrintradr = R_DMA_CH6_CLR_INTR,
+	  .ofirstadr   = R_DMA_CH6_FIRST,
+	  .ocmdadr     = R_DMA_CH6_CMD,
+	  .ostatusadr  = R_DMA_CH6_STATUS,
+	  .iclrintradr = R_DMA_CH7_CLR_INTR,
+	  .ifirstadr   = R_DMA_CH7_FIRST,
+	  .icmdadr     = R_DMA_CH7_CMD,
+	  .idescradr   = R_DMA_CH7_DESCR,
+	  .flags       = STD_FLAGS,
+	  .rx_ctrl     = DEF_RX,
+	  .tx_ctrl     = DEF_TX,
+	  .iseteop     = 2,
+	  .dma_owner   = dma_ser0,
+	  .io_if       = if_serial_0,
+#ifdef CONFIG_ETRAX_SERIAL_PORT0
+          .enabled  = 1,
+#ifdef CONFIG_ETRAX_SERIAL_PORT0_DMA6_OUT
+	  .dma_out_enabled = 1,
+	  .dma_out_nbr = SER0_TX_DMA_NBR,
+	  .dma_out_irq_nbr = SER0_DMA_TX_IRQ_NBR,
+	  .dma_out_irq_flags = IRQF_DISABLED,
+	  .dma_out_irq_description = "serial 0 dma tr",
+#else
+	  .dma_out_enabled = 0,
+	  .dma_out_nbr = UINT_MAX,
+	  .dma_out_irq_nbr = 0,
+	  .dma_out_irq_flags = 0,
+	  .dma_out_irq_description = NULL,
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT0_DMA7_IN
+	  .dma_in_enabled = 1,
+	  .dma_in_nbr = SER0_RX_DMA_NBR,
+	  .dma_in_irq_nbr = SER0_DMA_RX_IRQ_NBR,
+	  .dma_in_irq_flags = IRQF_DISABLED,
+	  .dma_in_irq_description = "serial 0 dma rec",
+#else
+	  .dma_in_enabled = 0,
+	  .dma_in_nbr = UINT_MAX,
+	  .dma_in_irq_nbr = 0,
+	  .dma_in_irq_flags = 0,
+	  .dma_in_irq_description = NULL,
+#endif
+#else
+          .enabled  = 0,
+	  .io_if_description = NULL,
+	  .dma_out_enabled = 0,
+	  .dma_in_enabled = 0
+#endif
+
+},  /* ttyS0 */
+#ifndef CONFIG_SVINTO_SIM
+	{ .baud        = DEF_BAUD,
+	  .ioport        = (unsigned char *)R_SERIAL1_CTRL,
+	  .irq         = 1U << 16, /* uses DMA 8 and 9 */
+	  .oclrintradr = R_DMA_CH8_CLR_INTR,
+	  .ofirstadr   = R_DMA_CH8_FIRST,
+	  .ocmdadr     = R_DMA_CH8_CMD,
+	  .ostatusadr  = R_DMA_CH8_STATUS,
+	  .iclrintradr = R_DMA_CH9_CLR_INTR,
+	  .ifirstadr   = R_DMA_CH9_FIRST,
+	  .icmdadr     = R_DMA_CH9_CMD,
+	  .idescradr   = R_DMA_CH9_DESCR,
+	  .flags       = STD_FLAGS,
+	  .rx_ctrl     = DEF_RX,
+	  .tx_ctrl     = DEF_TX,
+	  .iseteop     = 3,
+	  .dma_owner   = dma_ser1,
+	  .io_if       = if_serial_1,
+#ifdef CONFIG_ETRAX_SERIAL_PORT1
+          .enabled  = 1,
+	  .io_if_description = "ser1",
+#ifdef CONFIG_ETRAX_SERIAL_PORT1_DMA8_OUT
+	  .dma_out_enabled = 1,
+	  .dma_out_nbr = SER1_TX_DMA_NBR,
+	  .dma_out_irq_nbr = SER1_DMA_TX_IRQ_NBR,
+	  .dma_out_irq_flags = IRQF_DISABLED,
+	  .dma_out_irq_description = "serial 1 dma tr",
+#else
+	  .dma_out_enabled = 0,
+	  .dma_out_nbr = UINT_MAX,
+	  .dma_out_irq_nbr = 0,
+	  .dma_out_irq_flags = 0,
+	  .dma_out_irq_description = NULL,
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT1_DMA9_IN
+	  .dma_in_enabled = 1,
+	  .dma_in_nbr = SER1_RX_DMA_NBR,
+	  .dma_in_irq_nbr = SER1_DMA_RX_IRQ_NBR,
+	  .dma_in_irq_flags = IRQF_DISABLED,
+	  .dma_in_irq_description = "serial 1 dma rec",
+#else
+	  .dma_in_enabled = 0,
+	  .dma_in_enabled = 0,
+	  .dma_in_nbr = UINT_MAX,
+	  .dma_in_irq_nbr = 0,
+	  .dma_in_irq_flags = 0,
+	  .dma_in_irq_description = NULL,
+#endif
+#else
+          .enabled  = 0,
+	  .io_if_description = NULL,
+	  .dma_in_irq_nbr = 0,
+	  .dma_out_enabled = 0,
+	  .dma_in_enabled = 0
+#endif
+},  /* ttyS1 */
+
+	{ .baud        = DEF_BAUD,
+	  .ioport        = (unsigned char *)R_SERIAL2_CTRL,
+	  .irq         = 1U << 4,  /* uses DMA 2 and 3 */
+	  .oclrintradr = R_DMA_CH2_CLR_INTR,
+	  .ofirstadr   = R_DMA_CH2_FIRST,
+	  .ocmdadr     = R_DMA_CH2_CMD,
+	  .ostatusadr  = R_DMA_CH2_STATUS,
+	  .iclrintradr = R_DMA_CH3_CLR_INTR,
+	  .ifirstadr   = R_DMA_CH3_FIRST,
+	  .icmdadr     = R_DMA_CH3_CMD,
+	  .idescradr   = R_DMA_CH3_DESCR,
+	  .flags       = STD_FLAGS,
+	  .rx_ctrl     = DEF_RX,
+	  .tx_ctrl     = DEF_TX,
+	  .iseteop     = 0,
+	  .dma_owner   = dma_ser2,
+	  .io_if       = if_serial_2,
+#ifdef CONFIG_ETRAX_SERIAL_PORT2
+          .enabled  = 1,
+	  .io_if_description = "ser2",
+#ifdef CONFIG_ETRAX_SERIAL_PORT2_DMA2_OUT
+	  .dma_out_enabled = 1,
+	  .dma_out_nbr = SER2_TX_DMA_NBR,
+	  .dma_out_irq_nbr = SER2_DMA_TX_IRQ_NBR,
+	  .dma_out_irq_flags = IRQF_DISABLED,
+	  .dma_out_irq_description = "serial 2 dma tr",
+#else
+	  .dma_out_enabled = 0,
+	  .dma_out_nbr = UINT_MAX,
+	  .dma_out_irq_nbr = 0,
+	  .dma_out_irq_flags = 0,
+	  .dma_out_irq_description = NULL,
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT2_DMA3_IN
+	  .dma_in_enabled = 1,
+	  .dma_in_nbr = SER2_RX_DMA_NBR,
+	  .dma_in_irq_nbr = SER2_DMA_RX_IRQ_NBR,
+	  .dma_in_irq_flags = IRQF_DISABLED,
+	  .dma_in_irq_description = "serial 2 dma rec",
+#else
+	  .dma_in_enabled = 0,
+	  .dma_in_nbr = UINT_MAX,
+	  .dma_in_irq_nbr = 0,
+	  .dma_in_irq_flags = 0,
+	  .dma_in_irq_description = NULL,
+#endif
+#else
+          .enabled  = 0,
+	  .io_if_description = NULL,
+	  .dma_out_enabled = 0,
+	  .dma_in_enabled = 0
+#endif
+ },  /* ttyS2 */
+
+	{ .baud        = DEF_BAUD,
+	  .ioport        = (unsigned char *)R_SERIAL3_CTRL,
+	  .irq         = 1U << 8,  /* uses DMA 4 and 5 */
+	  .oclrintradr = R_DMA_CH4_CLR_INTR,
+	  .ofirstadr   = R_DMA_CH4_FIRST,
+	  .ocmdadr     = R_DMA_CH4_CMD,
+	  .ostatusadr  = R_DMA_CH4_STATUS,
+	  .iclrintradr = R_DMA_CH5_CLR_INTR,
+	  .ifirstadr   = R_DMA_CH5_FIRST,
+	  .icmdadr     = R_DMA_CH5_CMD,
+	  .idescradr   = R_DMA_CH5_DESCR,
+	  .flags       = STD_FLAGS,
+	  .rx_ctrl     = DEF_RX,
+	  .tx_ctrl     = DEF_TX,
+	  .iseteop     = 1,
+	  .dma_owner   = dma_ser3,
+	  .io_if       = if_serial_3,
+#ifdef CONFIG_ETRAX_SERIAL_PORT3
+          .enabled  = 1,
+	  .io_if_description = "ser3",
+#ifdef CONFIG_ETRAX_SERIAL_PORT3_DMA4_OUT
+	  .dma_out_enabled = 1,
+	  .dma_out_nbr = SER3_TX_DMA_NBR,
+	  .dma_out_irq_nbr = SER3_DMA_TX_IRQ_NBR,
+	  .dma_out_irq_flags = IRQF_DISABLED,
+	  .dma_out_irq_description = "serial 3 dma tr",
+#else
+	  .dma_out_enabled = 0,
+	  .dma_out_nbr = UINT_MAX,
+	  .dma_out_irq_nbr = 0,
+	  .dma_out_irq_flags = 0,
+	  .dma_out_irq_description = NULL,
+#endif
+#ifdef CONFIG_ETRAX_SERIAL_PORT3_DMA5_IN
+	  .dma_in_enabled = 1,
+	  .dma_in_nbr = SER3_RX_DMA_NBR,
+	  .dma_in_irq_nbr = SER3_DMA_RX_IRQ_NBR,
+	  .dma_in_irq_flags = IRQF_DISABLED,
+	  .dma_in_irq_description = "serial 3 dma rec",
+#else
+	  .dma_in_enabled = 0,
+	  .dma_in_nbr = UINT_MAX,
+	  .dma_in_irq_nbr = 0,
+	  .dma_in_irq_flags = 0,
+	  .dma_in_irq_description = NULL
+#endif
+#else
+          .enabled  = 0,
+	  .io_if_description = NULL,
+	  .dma_out_enabled = 0,
+	  .dma_in_enabled = 0
+#endif
+ }   /* ttyS3 */
+#endif
+};
+
+
+#define NR_PORTS (sizeof(rs_table)/sizeof(struct e100_serial))
+
+#ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
+static struct fast_timer fast_timers[NR_PORTS];
+#endif
+
+#ifdef CONFIG_ETRAX_SERIAL_PROC_ENTRY
+#define PROCSTAT(x) x
+struct ser_statistics_type {
+	int overrun_cnt;
+	int early_errors_cnt;
+	int ser_ints_ok_cnt;
+	int errors_cnt;
+	unsigned long int processing_flip;
+	unsigned long processing_flip_still_room;
+	unsigned long int timeout_flush_cnt;
+	int rx_dma_ints;
+	int tx_dma_ints;
+	int rx_tot;
+	int tx_tot;
+};
+
+static struct ser_statistics_type ser_stat[NR_PORTS];
+
+#else
+
+#define PROCSTAT(x)
+
+#endif /* CONFIG_ETRAX_SERIAL_PROC_ENTRY */
+
+/* RS-485 */
+#if defined(CONFIG_ETRAX_RS485)
+#ifdef CONFIG_ETRAX_FAST_TIMER
+static struct fast_timer fast_timers_rs485[NR_PORTS];
+#endif
+#if defined(CONFIG_ETRAX_RS485_ON_PA)
+static int rs485_pa_bit = CONFIG_ETRAX_RS485_ON_PA_BIT;
+#endif
+#if defined(CONFIG_ETRAX_RS485_ON_PORT_G)
+static int rs485_port_g_bit = CONFIG_ETRAX_RS485_ON_PORT_G_BIT;
+#endif
+#endif
+
+/* Info and macros needed for each ports extra control/status signals. */
+#define E100_STRUCT_PORT(line, pinname) \
+ ((CONFIG_ETRAX_SER##line##_##pinname##_ON_PA_BIT >= 0)? \
+		(R_PORT_PA_DATA): ( \
+ (CONFIG_ETRAX_SER##line##_##pinname##_ON_PB_BIT >= 0)? \
+		(R_PORT_PB_DATA):&dummy_ser[line]))
+
+#define E100_STRUCT_SHADOW(line, pinname) \
+ ((CONFIG_ETRAX_SER##line##_##pinname##_ON_PA_BIT >= 0)? \
+		(&port_pa_data_shadow): ( \
+ (CONFIG_ETRAX_SER##line##_##pinname##_ON_PB_BIT >= 0)? \
+		(&port_pb_data_shadow):&dummy_ser[line]))
+#define E100_STRUCT_MASK(line, pinname) \
+ ((CONFIG_ETRAX_SER##line##_##pinname##_ON_PA_BIT >= 0)? \
+		(1<<CONFIG_ETRAX_SER##line##_##pinname##_ON_PA_BIT): ( \
+ (CONFIG_ETRAX_SER##line##_##pinname##_ON_PB_BIT >= 0)? \
+		(1<<CONFIG_ETRAX_SER##line##_##pinname##_ON_PB_BIT):DUMMY_##pinname##_MASK))
+
+#define DUMMY_DTR_MASK 1
+#define DUMMY_RI_MASK  2
+#define DUMMY_DSR_MASK 4
+#define DUMMY_CD_MASK  8
+static unsigned char dummy_ser[NR_PORTS] = {0xFF, 0xFF, 0xFF,0xFF};
+
+/* If not all status pins are used or disabled, use mixed mode */
+#ifdef CONFIG_ETRAX_SERIAL_PORT0
+
+#define SER0_PA_BITSUM (CONFIG_ETRAX_SER0_DTR_ON_PA_BIT+CONFIG_ETRAX_SER0_RI_ON_PA_BIT+CONFIG_ETRAX_SER0_DSR_ON_PA_BIT+CONFIG_ETRAX_SER0_CD_ON_PA_BIT)
+
+#if SER0_PA_BITSUM != -4
+#  if CONFIG_ETRAX_SER0_DTR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER0_RI_ON_PA_BIT == -1
+#   ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER0_DSR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER0_CD_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#define SER0_PB_BITSUM (CONFIG_ETRAX_SER0_DTR_ON_PB_BIT+CONFIG_ETRAX_SER0_RI_ON_PB_BIT+CONFIG_ETRAX_SER0_DSR_ON_PB_BIT+CONFIG_ETRAX_SER0_CD_ON_PB_BIT)
+
+#if SER0_PB_BITSUM != -4
+#  if CONFIG_ETRAX_SER0_DTR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER0_RI_ON_PB_BIT == -1
+#   ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER0_DSR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER0_CD_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#endif /* PORT0 */
+
+
+#ifdef CONFIG_ETRAX_SERIAL_PORT1
+
+#define SER1_PA_BITSUM (CONFIG_ETRAX_SER1_DTR_ON_PA_BIT+CONFIG_ETRAX_SER1_RI_ON_PA_BIT+CONFIG_ETRAX_SER1_DSR_ON_PA_BIT+CONFIG_ETRAX_SER1_CD_ON_PA_BIT)
+
+#if SER1_PA_BITSUM != -4
+#  if CONFIG_ETRAX_SER1_DTR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER1_RI_ON_PA_BIT == -1
+#   ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER1_DSR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER1_CD_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#define SER1_PB_BITSUM (CONFIG_ETRAX_SER1_DTR_ON_PB_BIT+CONFIG_ETRAX_SER1_RI_ON_PB_BIT+CONFIG_ETRAX_SER1_DSR_ON_PB_BIT+CONFIG_ETRAX_SER1_CD_ON_PB_BIT)
+
+#if SER1_PB_BITSUM != -4
+#  if CONFIG_ETRAX_SER1_DTR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER1_RI_ON_PB_BIT == -1
+#   ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER1_DSR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER1_CD_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#endif /* PORT1 */
+
+#ifdef CONFIG_ETRAX_SERIAL_PORT2
+
+#define SER2_PA_BITSUM (CONFIG_ETRAX_SER2_DTR_ON_PA_BIT+CONFIG_ETRAX_SER2_RI_ON_PA_BIT+CONFIG_ETRAX_SER2_DSR_ON_PA_BIT+CONFIG_ETRAX_SER2_CD_ON_PA_BIT)
+
+#if SER2_PA_BITSUM != -4
+#  if CONFIG_ETRAX_SER2_DTR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER2_RI_ON_PA_BIT == -1
+#   ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER2_DSR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER2_CD_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#define SER2_PB_BITSUM (CONFIG_ETRAX_SER2_DTR_ON_PB_BIT+CONFIG_ETRAX_SER2_RI_ON_PB_BIT+CONFIG_ETRAX_SER2_DSR_ON_PB_BIT+CONFIG_ETRAX_SER2_CD_ON_PB_BIT)
+
+#if SER2_PB_BITSUM != -4
+#  if CONFIG_ETRAX_SER2_DTR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER2_RI_ON_PB_BIT == -1
+#   ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER2_DSR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER2_CD_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#endif /* PORT2 */
+
+#ifdef CONFIG_ETRAX_SERIAL_PORT3
+
+#define SER3_PA_BITSUM (CONFIG_ETRAX_SER3_DTR_ON_PA_BIT+CONFIG_ETRAX_SER3_RI_ON_PA_BIT+CONFIG_ETRAX_SER3_DSR_ON_PA_BIT+CONFIG_ETRAX_SER3_CD_ON_PA_BIT)
+
+#if SER3_PA_BITSUM != -4
+#  if CONFIG_ETRAX_SER3_DTR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER3_RI_ON_PA_BIT == -1
+#   ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER3_DSR_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER3_CD_ON_PA_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#define SER3_PB_BITSUM (CONFIG_ETRAX_SER3_DTR_ON_PB_BIT+CONFIG_ETRAX_SER3_RI_ON_PB_BIT+CONFIG_ETRAX_SER3_DSR_ON_PB_BIT+CONFIG_ETRAX_SER3_CD_ON_PB_BIT)
+
+#if SER3_PB_BITSUM != -4
+#  if CONFIG_ETRAX_SER3_DTR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#   endif
+# if CONFIG_ETRAX_SER3_RI_ON_PB_BIT == -1
+#   ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#     define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#   endif
+#  endif
+#  if CONFIG_ETRAX_SER3_DSR_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#  if CONFIG_ETRAX_SER3_CD_ON_PB_BIT == -1
+#    ifndef CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED
+#      define CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED 1
+#    endif
+#  endif
+#endif
+
+#endif /* PORT3 */
+
+
+#if defined(CONFIG_ETRAX_SER0_DTR_RI_DSR_CD_MIXED) || \
+    defined(CONFIG_ETRAX_SER1_DTR_RI_DSR_CD_MIXED) || \
+    defined(CONFIG_ETRAX_SER2_DTR_RI_DSR_CD_MIXED) || \
+    defined(CONFIG_ETRAX_SER3_DTR_RI_DSR_CD_MIXED)
+#define CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED
+#endif
+
+#ifdef CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED
+/* The pins can be mixed on PA and PB */
+#define CONTROL_PINS_PORT_NOT_USED(line) \
+  &dummy_ser[line], &dummy_ser[line], \
+  &dummy_ser[line], &dummy_ser[line], \
+  &dummy_ser[line], &dummy_ser[line], \
+  &dummy_ser[line], &dummy_ser[line], \
+  DUMMY_DTR_MASK, DUMMY_RI_MASK, DUMMY_DSR_MASK, DUMMY_CD_MASK
+
+
+struct control_pins
+{
+	volatile unsigned char *dtr_port;
+	unsigned char          *dtr_shadow;
+	volatile unsigned char *ri_port;
+	unsigned char          *ri_shadow;
+	volatile unsigned char *dsr_port;
+	unsigned char          *dsr_shadow;
+	volatile unsigned char *cd_port;
+	unsigned char          *cd_shadow;
+
+	unsigned char dtr_mask;
+	unsigned char ri_mask;
+	unsigned char dsr_mask;
+	unsigned char cd_mask;
+};
+
+static const struct control_pins e100_modem_pins[NR_PORTS] =
+{
+	/* Ser 0 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT0
+	E100_STRUCT_PORT(0,DTR), E100_STRUCT_SHADOW(0,DTR),
+	E100_STRUCT_PORT(0,RI),  E100_STRUCT_SHADOW(0,RI),
+	E100_STRUCT_PORT(0,DSR), E100_STRUCT_SHADOW(0,DSR),
+	E100_STRUCT_PORT(0,CD),  E100_STRUCT_SHADOW(0,CD),
+	E100_STRUCT_MASK(0,DTR),
+	E100_STRUCT_MASK(0,RI),
+	E100_STRUCT_MASK(0,DSR),
+	E100_STRUCT_MASK(0,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(0)
+#endif
+	},
+
+	/* Ser 1 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT1
+	E100_STRUCT_PORT(1,DTR), E100_STRUCT_SHADOW(1,DTR),
+	E100_STRUCT_PORT(1,RI),  E100_STRUCT_SHADOW(1,RI),
+	E100_STRUCT_PORT(1,DSR), E100_STRUCT_SHADOW(1,DSR),
+	E100_STRUCT_PORT(1,CD),  E100_STRUCT_SHADOW(1,CD),
+	E100_STRUCT_MASK(1,DTR),
+	E100_STRUCT_MASK(1,RI),
+	E100_STRUCT_MASK(1,DSR),
+	E100_STRUCT_MASK(1,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(1)
+#endif
+	},
+
+	/* Ser 2 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT2
+	E100_STRUCT_PORT(2,DTR), E100_STRUCT_SHADOW(2,DTR),
+	E100_STRUCT_PORT(2,RI),  E100_STRUCT_SHADOW(2,RI),
+	E100_STRUCT_PORT(2,DSR), E100_STRUCT_SHADOW(2,DSR),
+	E100_STRUCT_PORT(2,CD),  E100_STRUCT_SHADOW(2,CD),
+	E100_STRUCT_MASK(2,DTR),
+	E100_STRUCT_MASK(2,RI),
+	E100_STRUCT_MASK(2,DSR),
+	E100_STRUCT_MASK(2,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(2)
+#endif
+	},
+
+	/* Ser 3 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT3
+	E100_STRUCT_PORT(3,DTR), E100_STRUCT_SHADOW(3,DTR),
+	E100_STRUCT_PORT(3,RI),  E100_STRUCT_SHADOW(3,RI),
+	E100_STRUCT_PORT(3,DSR), E100_STRUCT_SHADOW(3,DSR),
+	E100_STRUCT_PORT(3,CD),  E100_STRUCT_SHADOW(3,CD),
+	E100_STRUCT_MASK(3,DTR),
+	E100_STRUCT_MASK(3,RI),
+	E100_STRUCT_MASK(3,DSR),
+	E100_STRUCT_MASK(3,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(3)
+#endif
+	}
+};
+#else  /* CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED */
+
+/* All pins are on either PA or PB for each serial port */
+#define CONTROL_PINS_PORT_NOT_USED(line) \
+  &dummy_ser[line], &dummy_ser[line], \
+  DUMMY_DTR_MASK, DUMMY_RI_MASK, DUMMY_DSR_MASK, DUMMY_CD_MASK
+
+
+struct control_pins
+{
+	volatile unsigned char *port;
+	unsigned char          *shadow;
+
+	unsigned char dtr_mask;
+	unsigned char ri_mask;
+	unsigned char dsr_mask;
+	unsigned char cd_mask;
+};
+
+#define dtr_port port
+#define dtr_shadow shadow
+#define ri_port port
+#define ri_shadow shadow
+#define dsr_port port
+#define dsr_shadow shadow
+#define cd_port port
+#define cd_shadow shadow
+
+static const struct control_pins e100_modem_pins[NR_PORTS] =
+{
+	/* Ser 0 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT0
+	E100_STRUCT_PORT(0,DTR), E100_STRUCT_SHADOW(0,DTR),
+	E100_STRUCT_MASK(0,DTR),
+	E100_STRUCT_MASK(0,RI),
+	E100_STRUCT_MASK(0,DSR),
+	E100_STRUCT_MASK(0,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(0)
+#endif
+	},
+
+	/* Ser 1 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT1
+	E100_STRUCT_PORT(1,DTR), E100_STRUCT_SHADOW(1,DTR),
+	E100_STRUCT_MASK(1,DTR),
+	E100_STRUCT_MASK(1,RI),
+	E100_STRUCT_MASK(1,DSR),
+	E100_STRUCT_MASK(1,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(1)
+#endif
+	},
+
+	/* Ser 2 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT2
+	E100_STRUCT_PORT(2,DTR), E100_STRUCT_SHADOW(2,DTR),
+	E100_STRUCT_MASK(2,DTR),
+	E100_STRUCT_MASK(2,RI),
+	E100_STRUCT_MASK(2,DSR),
+	E100_STRUCT_MASK(2,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(2)
+#endif
+	},
+
+	/* Ser 3 */
+	{
+#ifdef CONFIG_ETRAX_SERIAL_PORT3
+	E100_STRUCT_PORT(3,DTR), E100_STRUCT_SHADOW(3,DTR),
+	E100_STRUCT_MASK(3,DTR),
+	E100_STRUCT_MASK(3,RI),
+	E100_STRUCT_MASK(3,DSR),
+	E100_STRUCT_MASK(3,CD)
+#else
+	CONTROL_PINS_PORT_NOT_USED(3)
+#endif
+	}
+};
+#endif /* !CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED */
+
+#define E100_RTS_MASK 0x20
+#define E100_CTS_MASK 0x40
+
+/* All serial port signals are active low:
+ * active   = 0 -> 3.3V to RS-232 driver -> -12V on RS-232 level
+ * inactive = 1 -> 0V   to RS-232 driver -> +12V on RS-232 level
+ *
+ * These macros returns the pin value: 0=0V, >=1 = 3.3V on ETRAX chip
+ */
+
+/* Output */
+#define E100_RTS_GET(info) ((info)->rx_ctrl & E100_RTS_MASK)
+/* Input */
+#define E100_CTS_GET(info) ((info)->ioport[REG_STATUS] & E100_CTS_MASK)
+
+/* These are typically PA or PB and 0 means 0V, 1 means 3.3V */
+/* Is an output */
+#define E100_DTR_GET(info) ((*e100_modem_pins[(info)->line].dtr_shadow) & e100_modem_pins[(info)->line].dtr_mask)
+
+/* Normally inputs */
+#define E100_RI_GET(info) ((*e100_modem_pins[(info)->line].ri_port) & e100_modem_pins[(info)->line].ri_mask)
+#define E100_CD_GET(info) ((*e100_modem_pins[(info)->line].cd_port) & e100_modem_pins[(info)->line].cd_mask)
+
+/* Input */
+#define E100_DSR_GET(info) ((*e100_modem_pins[(info)->line].dsr_port) & e100_modem_pins[(info)->line].dsr_mask)
+
+
+/*
+ * tmp_buf is used as a temporary buffer by serial_write.  We need to
+ * lock it in case the memcpy_fromfs blocks while swapping in a page,
+ * and some other program tries to do a serial write at the same time.
+ * Since the lock will only come under contention when the system is
+ * swapping and available memory is low, it makes sense to share one
+ * buffer across all the serial ports, since it significantly saves
+ * memory if large numbers of serial ports are open.
+ */
+static unsigned char *tmp_buf;
+static DEFINE_MUTEX(tmp_buf_mutex);
+
+/* Calculate the chartime depending on baudrate, numbor of bits etc. */
+static void update_char_time(struct e100_serial * info)
+{
+	tcflag_t cflags = info->port.tty->termios->c_cflag;
+	int bits;
+
+	/* calc. number of bits / data byte */
+	/* databits + startbit and 1 stopbit */
+	if ((cflags & CSIZE) == CS7)
+		bits = 9;
+	else
+		bits = 10;
+
+	if (cflags & CSTOPB)     /* 2 stopbits ? */
+		bits++;
+
+	if (cflags & PARENB)     /* parity bit ? */
+		bits++;
+
+	/* calc timeout */
+	info->char_time_usec = ((bits * 1000000) / info->baud) + 1;
+	info->flush_time_usec = 4*info->char_time_usec;
+	if (info->flush_time_usec < MIN_FLUSH_TIME_USEC)
+		info->flush_time_usec = MIN_FLUSH_TIME_USEC;
+
+}
+
+/*
+ * This function maps from the Bxxxx defines in asm/termbits.h into real
+ * baud rates.
+ */
+
+static int
+cflag_to_baud(unsigned int cflag)
+{
+	static int baud_table[] = {
+		0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
+		4800, 9600, 19200, 38400 };
+
+	static int ext_baud_table[] = {
+		0, 57600, 115200, 230400, 460800, 921600, 1843200, 6250000,
+                0, 0, 0, 0, 0, 0, 0, 0 };
+
+	if (cflag & CBAUDEX)
+		return ext_baud_table[(cflag & CBAUD) & ~CBAUDEX];
+	else
+		return baud_table[cflag & CBAUD];
+}
+
+/* and this maps to an etrax100 hardware baud constant */
+
+static unsigned char
+cflag_to_etrax_baud(unsigned int cflag)
+{
+	char retval;
+
+	static char baud_table[] = {
+		-1, -1, -1, -1, -1, -1, -1, 0, 1, 2, -1, 3, 4, 5, 6, 7 };
+
+	static char ext_baud_table[] = {
+		-1, 8, 9, 10, 11, 12, 13, 14, -1, -1, -1, -1, -1, -1, -1, -1 };
+
+	if (cflag & CBAUDEX)
+		retval = ext_baud_table[(cflag & CBAUD) & ~CBAUDEX];
+	else
+		retval = baud_table[cflag & CBAUD];
+
+	if (retval < 0) {
+		printk(KERN_WARNING "serdriver tried setting invalid baud rate, flags %x.\n", cflag);
+		retval = 5; /* choose default 9600 instead */
+	}
+
+	return retval | (retval << 4); /* choose same for both TX and RX */
+}
+
+
+/* Various static support functions */
+
+/* Functions to set or clear DTR/RTS on the requested line */
+/* It is complicated by the fact that RTS is a serial port register, while
+ * DTR might not be implemented in the HW at all, and if it is, it can be on
+ * any general port.
+ */
+
+
+static inline void
+e100_dtr(struct e100_serial *info, int set)
+{
+#ifndef CONFIG_SVINTO_SIM
+	unsigned char mask = e100_modem_pins[info->line].dtr_mask;
+
+#ifdef SERIAL_DEBUG_IO
+	printk("ser%i dtr %i mask: 0x%02X\n", info->line, set, mask);
+	printk("ser%i shadow before 0x%02X get: %i\n",
+	       info->line, *e100_modem_pins[info->line].dtr_shadow,
+	       E100_DTR_GET(info));
+#endif
+	/* DTR is active low */
+	{
+		unsigned long flags;
+
+		local_irq_save(flags);
+		*e100_modem_pins[info->line].dtr_shadow &= ~mask;
+		*e100_modem_pins[info->line].dtr_shadow |= (set ? 0 : mask);
+		*e100_modem_pins[info->line].dtr_port = *e100_modem_pins[info->line].dtr_shadow;
+		local_irq_restore(flags);
+	}
+
+#ifdef SERIAL_DEBUG_IO
+	printk("ser%i shadow after 0x%02X get: %i\n",
+	       info->line, *e100_modem_pins[info->line].dtr_shadow,
+	       E100_DTR_GET(info));
+#endif
+#endif
+}
+
+/* set = 0 means 3.3V on the pin, bitvalue: 0=active, 1=inactive
+ *                                          0=0V    , 1=3.3V
+ */
+static inline void
+e100_rts(struct e100_serial *info, int set)
+{
+#ifndef CONFIG_SVINTO_SIM
+	unsigned long flags;
+	local_irq_save(flags);
+	info->rx_ctrl &= ~E100_RTS_MASK;
+	info->rx_ctrl |= (set ? 0 : E100_RTS_MASK);  /* RTS is active low */
+	info->ioport[REG_REC_CTRL] = info->rx_ctrl;
+	local_irq_restore(flags);
+#ifdef SERIAL_DEBUG_IO
+	printk("ser%i rts %i\n", info->line, set);
+#endif
+#endif
+}
+
+
+/* If this behaves as a modem, RI and CD is an output */
+static inline void
+e100_ri_out(struct e100_serial *info, int set)
+{
+#ifndef CONFIG_SVINTO_SIM
+	/* RI is active low */
+	{
+		unsigned char mask = e100_modem_pins[info->line].ri_mask;
+		unsigned long flags;
+
+		local_irq_save(flags);
+		*e100_modem_pins[info->line].ri_shadow &= ~mask;
+		*e100_modem_pins[info->line].ri_shadow |= (set ? 0 : mask);
+		*e100_modem_pins[info->line].ri_port = *e100_modem_pins[info->line].ri_shadow;
+		local_irq_restore(flags);
+	}
+#endif
+}
+static inline void
+e100_cd_out(struct e100_serial *info, int set)
+{
+#ifndef CONFIG_SVINTO_SIM
+	/* CD is active low */
+	{
+		unsigned char mask = e100_modem_pins[info->line].cd_mask;
+		unsigned long flags;
+
+		local_irq_save(flags);
+		*e100_modem_pins[info->line].cd_shadow &= ~mask;
+		*e100_modem_pins[info->line].cd_shadow |= (set ? 0 : mask);
+		*e100_modem_pins[info->line].cd_port = *e100_modem_pins[info->line].cd_shadow;
+		local_irq_restore(flags);
+	}
+#endif
+}
+
+static inline void
+e100_disable_rx(struct e100_serial *info)
+{
+#ifndef CONFIG_SVINTO_SIM
+	/* disable the receiver */
+	info->ioport[REG_REC_CTRL] =
+		(info->rx_ctrl &= ~IO_MASK(R_SERIAL0_REC_CTRL, rec_enable));
+#endif
+}
+
+static inline void
+e100_enable_rx(struct e100_serial *info)
+{
+#ifndef CONFIG_SVINTO_SIM
+	/* enable the receiver */
+	info->ioport[REG_REC_CTRL] =
+		(info->rx_ctrl |= IO_MASK(R_SERIAL0_REC_CTRL, rec_enable));
+#endif
+}
+
+/* the rx DMA uses both the dma_descr and the dma_eop interrupts */
+
+static inline void
+e100_disable_rxdma_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("rxdma_irq(%d): 0\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ disable_rxdma_irq %i\n", info->line));
+	*R_IRQ_MASK2_CLR = (info->irq << 2) | (info->irq << 3);
+}
+
+static inline void
+e100_enable_rxdma_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("rxdma_irq(%d): 1\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ enable_rxdma_irq %i\n", info->line));
+	*R_IRQ_MASK2_SET = (info->irq << 2) | (info->irq << 3);
+}
+
+/* the tx DMA uses only dma_descr interrupt */
+
+static void e100_disable_txdma_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("txdma_irq(%d): 0\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ disable_txdma_irq %i\n", info->line));
+	*R_IRQ_MASK2_CLR = info->irq;
+}
+
+static void e100_enable_txdma_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("txdma_irq(%d): 1\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ enable_txdma_irq %i\n", info->line));
+	*R_IRQ_MASK2_SET = info->irq;
+}
+
+static void e100_disable_txdma_channel(struct e100_serial *info)
+{
+	unsigned long flags;
+
+	/* Disable output DMA channel for the serial port in question
+	 * ( set to something other than serialX)
+	 */
+	local_irq_save(flags);
+	DFLOW(DEBUG_LOG(info->line, "disable_txdma_channel %i\n", info->line));
+	if (info->line == 0) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma6)) ==
+		    IO_STATE(R_GEN_CONFIG, dma6, serial0)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma6);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma6, unused);
+		}
+	} else if (info->line == 1) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma8)) ==
+		    IO_STATE(R_GEN_CONFIG, dma8, serial1)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma8);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma8, usb);
+		}
+	} else if (info->line == 2) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma2)) ==
+		    IO_STATE(R_GEN_CONFIG, dma2, serial2)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma2);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma2, par0);
+		}
+	} else if (info->line == 3) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma4)) ==
+		    IO_STATE(R_GEN_CONFIG, dma4, serial3)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma4);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma4, par1);
+		}
+	}
+	*R_GEN_CONFIG = genconfig_shadow;
+	local_irq_restore(flags);
+}
+
+
+static void e100_enable_txdma_channel(struct e100_serial *info)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	DFLOW(DEBUG_LOG(info->line, "enable_txdma_channel %i\n", info->line));
+	/* Enable output DMA channel for the serial port in question */
+	if (info->line == 0) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma6);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma6, serial0);
+	} else if (info->line == 1) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma8);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma8, serial1);
+	} else if (info->line == 2) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma2);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma2, serial2);
+	} else if (info->line == 3) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma4);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma4, serial3);
+	}
+	*R_GEN_CONFIG = genconfig_shadow;
+	local_irq_restore(flags);
+}
+
+static void e100_disable_rxdma_channel(struct e100_serial *info)
+{
+	unsigned long flags;
+
+	/* Disable input DMA channel for the serial port in question
+	 * ( set to something other than serialX)
+	 */
+	local_irq_save(flags);
+	if (info->line == 0) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma7)) ==
+		    IO_STATE(R_GEN_CONFIG, dma7, serial0)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma7);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma7, unused);
+		}
+	} else if (info->line == 1) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma9)) ==
+		    IO_STATE(R_GEN_CONFIG, dma9, serial1)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma9);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma9, usb);
+		}
+	} else if (info->line == 2) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma3)) ==
+		    IO_STATE(R_GEN_CONFIG, dma3, serial2)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma3);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma3, par0);
+		}
+	} else if (info->line == 3) {
+		if ((genconfig_shadow & IO_MASK(R_GEN_CONFIG, dma5)) ==
+		    IO_STATE(R_GEN_CONFIG, dma5, serial3)) {
+			genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma5);
+			genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma5, par1);
+		}
+	}
+	*R_GEN_CONFIG = genconfig_shadow;
+	local_irq_restore(flags);
+}
+
+
+static void e100_enable_rxdma_channel(struct e100_serial *info)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	/* Enable input DMA channel for the serial port in question */
+	if (info->line == 0) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma7);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma7, serial0);
+	} else if (info->line == 1) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma9);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma9, serial1);
+	} else if (info->line == 2) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma3);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma3, serial2);
+	} else if (info->line == 3) {
+		genconfig_shadow &=  ~IO_MASK(R_GEN_CONFIG, dma5);
+		genconfig_shadow |= IO_STATE(R_GEN_CONFIG, dma5, serial3);
+	}
+	*R_GEN_CONFIG = genconfig_shadow;
+	local_irq_restore(flags);
+}
+
+#ifdef SERIAL_HANDLE_EARLY_ERRORS
+/* in order to detect and fix errors on the first byte
+   we have to use the serial interrupts as well. */
+
+static inline void
+e100_disable_serial_data_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_irq(%d): 0\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ disable data_irq %i\n", info->line));
+	*R_IRQ_MASK1_CLR = (1U << (8+2*info->line));
+}
+
+static inline void
+e100_enable_serial_data_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_irq(%d): 1\n",info->line);
+	printk("**** %d = %d\n",
+	       (8+2*info->line),
+	       (1U << (8+2*info->line)));
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ enable data_irq %i\n", info->line));
+	*R_IRQ_MASK1_SET = (1U << (8+2*info->line));
+}
+#endif
+
+static inline void
+e100_disable_serial_tx_ready_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_tx_irq(%d): 0\n",info->line);
+#endif
+	DINTR1(DEBUG_LOG(info->line,"IRQ disable ready_irq %i\n", info->line));
+	*R_IRQ_MASK1_CLR = (1U << (8+1+2*info->line));
+}
+
+static inline void
+e100_enable_serial_tx_ready_irq(struct e100_serial *info)
+{
+#ifdef SERIAL_DEBUG_INTR
+	printk("ser_tx_irq(%d): 1\n",info->line);
+	printk("**** %d = %d\n",
+	       (8+1+2*info->line),
+	       (1U << (8+1+2*info->line)));
+#endif
+	DINTR2(DEBUG_LOG(info->line,"IRQ enable ready_irq %i\n", info->line));
+	*R_IRQ_MASK1_SET = (1U << (8+1+2*info->line));
+}
+
+static inline void e100_enable_rx_irq(struct e100_serial *info)
+{
+	if (info->uses_dma_in)
+		e100_enable_rxdma_irq(info);
+	else
+		e100_enable_serial_data_irq(info);
+}
+static inline void e100_disable_rx_irq(struct e100_serial *info)
+{
+	if (info->uses_dma_in)
+		e100_disable_rxdma_irq(info);
+	else
+		e100_disable_serial_data_irq(info);
+}
+
+#if defined(CONFIG_ETRAX_RS485)
+/* Enable RS-485 mode on selected port. This is UGLY. */
+static int
+e100_enable_rs485(struct tty_struct *tty, struct serial_rs485 *r)
+{
+	struct e100_serial * info = (struct e100_serial *)tty->driver_data;
+
+#if defined(CONFIG_ETRAX_RS485_ON_PA)
+	*R_PORT_PA_DATA = port_pa_data_shadow |= (1 << rs485_pa_bit);
+#endif
+#if defined(CONFIG_ETRAX_RS485_ON_PORT_G)
+	REG_SHADOW_SET(R_PORT_G_DATA,  port_g_data_shadow,
+		       rs485_port_g_bit, 1);
+#endif
+#if defined(CONFIG_ETRAX_RS485_LTC1387)
+	REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow,
+		       CONFIG_ETRAX_RS485_LTC1387_DXEN_PORT_G_BIT, 1);
+	REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow,
+		       CONFIG_ETRAX_RS485_LTC1387_RXEN_PORT_G_BIT, 1);
+#endif
+
+	info->rs485 = *r;
+
+	/* Maximum delay before RTS equal to 1000 */
+	if (info->rs485.delay_rts_before_send >= 1000)
+		info->rs485.delay_rts_before_send = 1000;
+
+/*	printk("rts: on send = %i, after = %i, enabled = %i",
+		    info->rs485.rts_on_send,
+		    info->rs485.rts_after_sent,
+		    info->rs485.enabled
+	);
+*/
+	return 0;
+}
+
+static int
+e100_write_rs485(struct tty_struct *tty,
+                 const unsigned char *buf, int count)
+{
+	struct e100_serial * info = (struct e100_serial *)tty->driver_data;
+	int old_value = (info->rs485.flags) & SER_RS485_ENABLED;
+
+	/* rs485 is always implicitly enabled if we're using the ioctl()
+	 * but it doesn't have to be set in the serial_rs485
+	 * (to be backward compatible with old apps)
+	 * So we store, set and restore it.
+	 */
+	info->rs485.flags |= SER_RS485_ENABLED;
+	/* rs_write now deals with RS485 if enabled */
+	count = rs_write(tty, buf, count);
+	if (!old_value)
+		info->rs485.flags &= ~(SER_RS485_ENABLED);
+	return count;
+}
+
+#ifdef CONFIG_ETRAX_FAST_TIMER
+/* Timer function to toggle RTS when using FAST_TIMER */
+static void rs485_toggle_rts_timer_function(unsigned long data)
+{
+	struct e100_serial *info = (struct e100_serial *)data;
+
+	fast_timers_rs485[info->line].function = NULL;
+	e100_rts(info, (info->rs485.flags & SER_RS485_RTS_AFTER_SEND));
+#if defined(CONFIG_ETRAX_RS485_DISABLE_RECEIVER)
+	e100_enable_rx(info);
+	e100_enable_rx_irq(info);
+#endif
+}
+#endif
+#endif /* CONFIG_ETRAX_RS485 */
+
+/*
+ * ------------------------------------------------------------
+ * rs_stop() and rs_start()
+ *
+ * This routines are called before setting or resetting tty->stopped.
+ * They enable or disable transmitter using the XOFF registers, as necessary.
+ * ------------------------------------------------------------
+ */
+
+static void
+rs_stop(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	if (info) {
+		unsigned long flags;
+		unsigned long xoff;
+
+		local_irq_save(flags);
+		DFLOW(DEBUG_LOG(info->line, "XOFF rs_stop xmit %i\n",
+				CIRC_CNT(info->xmit.head,
+					 info->xmit.tail,SERIAL_XMIT_SIZE)));
+
+		xoff = IO_FIELD(R_SERIAL0_XOFF, xoff_char,
+				STOP_CHAR(info->port.tty));
+		xoff |= IO_STATE(R_SERIAL0_XOFF, tx_stop, stop);
+		if (tty->termios->c_iflag & IXON ) {
+			xoff |= IO_STATE(R_SERIAL0_XOFF, auto_xoff, enable);
+		}
+
+		*((unsigned long *)&info->ioport[REG_XOFF]) = xoff;
+		local_irq_restore(flags);
+	}
+}
+
+static void
+rs_start(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	if (info) {
+		unsigned long flags;
+		unsigned long xoff;
+
+		local_irq_save(flags);
+		DFLOW(DEBUG_LOG(info->line, "XOFF rs_start xmit %i\n",
+				CIRC_CNT(info->xmit.head,
+					 info->xmit.tail,SERIAL_XMIT_SIZE)));
+		xoff = IO_FIELD(R_SERIAL0_XOFF, xoff_char, STOP_CHAR(tty));
+		xoff |= IO_STATE(R_SERIAL0_XOFF, tx_stop, enable);
+		if (tty->termios->c_iflag & IXON ) {
+			xoff |= IO_STATE(R_SERIAL0_XOFF, auto_xoff, enable);
+		}
+
+		*((unsigned long *)&info->ioport[REG_XOFF]) = xoff;
+		if (!info->uses_dma_out &&
+		    info->xmit.head != info->xmit.tail && info->xmit.buf)
+			e100_enable_serial_tx_ready_irq(info);
+
+		local_irq_restore(flags);
+	}
+}
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * Here starts the interrupt handling routines.  All of the following
+ * subroutines are declared as inline and are folded into
+ * rs_interrupt().  They were separated out for readability's sake.
+ *
+ * Note: rs_interrupt() is a "fast" interrupt, which means that it
+ * runs with interrupts turned off.  People who may want to modify
+ * rs_interrupt() should try to keep the interrupt handler as fast as
+ * possible.  After you are done making modifications, it is not a bad
+ * idea to do:
+ *
+ * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
+ *
+ * and look at the resulting assemble code in serial.s.
+ *
+ * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
+ * -----------------------------------------------------------------------
+ */
+
+/*
+ * This routine is used by the interrupt handler to schedule
+ * processing in the software interrupt portion of the driver.
+ */
+static void rs_sched_event(struct e100_serial *info, int event)
+{
+	if (info->event & (1 << event))
+		return;
+	info->event |= 1 << event;
+	schedule_work(&info->work);
+}
+
+/* The output DMA channel is free - use it to send as many chars as possible
+ * NOTES:
+ *   We don't pay attention to info->x_char, which means if the TTY wants to
+ *   use XON/XOFF it will set info->x_char but we won't send any X char!
+ *
+ *   To implement this, we'd just start a DMA send of 1 byte pointing at a
+ *   buffer containing the X char, and skip updating xmit. We'd also have to
+ *   check if the last sent char was the X char when we enter this function
+ *   the next time, to avoid updating xmit with the sent X value.
+ */
+
+static void
+transmit_chars_dma(struct e100_serial *info)
+{
+	unsigned int c, sentl;
+	struct etrax_dma_descr *descr;
+
+#ifdef CONFIG_SVINTO_SIM
+	/* This will output too little if tail is not 0 always since
+	 * we don't reloop to send the other part. Anyway this SHOULD be a
+	 * no-op - transmit_chars_dma would never really be called during sim
+	 * since rs_write does not write into the xmit buffer then.
+	 */
+	if (info->xmit.tail)
+		printk("Error in serial.c:transmit_chars-dma(), tail!=0\n");
+	if (info->xmit.head != info->xmit.tail) {
+		SIMCOUT(info->xmit.buf + info->xmit.tail,
+			CIRC_CNT(info->xmit.head,
+				 info->xmit.tail,
+				 SERIAL_XMIT_SIZE));
+		info->xmit.head = info->xmit.tail;  /* move back head */
+		info->tr_running = 0;
+	}
+	return;
+#endif
+	/* acknowledge both dma_descr and dma_eop irq in R_DMA_CHx_CLR_INTR */
+	*info->oclrintradr =
+		IO_STATE(R_DMA_CH6_CLR_INTR, clr_descr, do) |
+		IO_STATE(R_DMA_CH6_CLR_INTR, clr_eop, do);
+
+#ifdef SERIAL_DEBUG_INTR
+	if (info->line == SERIAL_DEBUG_LINE)
+		printk("tc\n");
+#endif
+	if (!info->tr_running) {
+		/* weirdo... we shouldn't get here! */
+		printk(KERN_WARNING "Achtung: transmit_chars_dma with !tr_running\n");
+		return;
+	}
+
+	descr = &info->tr_descr;
+
+	/* first get the amount of bytes sent during the last DMA transfer,
+	   and update xmit accordingly */
+
+	/* if the stop bit was not set, all data has been sent */
+	if (!(descr->status & d_stop)) {
+		sentl = descr->sw_len;
+	} else
+		/* otherwise we find the amount of data sent here */
+		sentl = descr->hw_len;
+
+	DFLOW(DEBUG_LOG(info->line, "TX %i done\n", sentl));
+
+	/* update stats */
+	info->icount.tx += sentl;
+
+	/* update xmit buffer */
+	info->xmit.tail = (info->xmit.tail + sentl) & (SERIAL_XMIT_SIZE - 1);
+
+	/* if there is only a few chars left in the buf, wake up the blocked
+	   write if any */
+	if (CIRC_CNT(info->xmit.head,
+		     info->xmit.tail,
+		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
+		rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
+
+	/* find out the largest amount of consecutive bytes we want to send now */
+
+	c = CIRC_CNT_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+
+	/* Don't send all in one DMA transfer - divide it so we wake up
+	 * application before all is sent
+	 */
+
+	if (c >= 4*WAKEUP_CHARS)
+		c = c/2;
+
+	if (c <= 0) {
+		/* our job here is done, don't schedule any new DMA transfer */
+		info->tr_running = 0;
+
+#if defined(CONFIG_ETRAX_RS485) && defined(CONFIG_ETRAX_FAST_TIMER)
+		if (info->rs485.flags & SER_RS485_ENABLED) {
+			/* Set a short timer to toggle RTS */
+			start_one_shot_timer(&fast_timers_rs485[info->line],
+			                     rs485_toggle_rts_timer_function,
+			                     (unsigned long)info,
+			                     info->char_time_usec*2,
+			                     "RS-485");
+		}
+#endif /* RS485 */
+		return;
+	}
+
+	/* ok we can schedule a dma send of c chars starting at info->xmit.tail */
+	/* set up the descriptor correctly for output */
+	DFLOW(DEBUG_LOG(info->line, "TX %i\n", c));
+	descr->ctrl = d_int | d_eol | d_wait; /* Wait needed for tty_wait_until_sent() */
+	descr->sw_len = c;
+	descr->buf = virt_to_phys(info->xmit.buf + info->xmit.tail);
+	descr->status = 0;
+
+	*info->ofirstadr = virt_to_phys(descr); /* write to R_DMAx_FIRST */
+	*info->ocmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, start);
+
+	/* DMA is now running (hopefully) */
+} /* transmit_chars_dma */
+
+static void
+start_transmit(struct e100_serial *info)
+{
+#if 0
+	if (info->line == SERIAL_DEBUG_LINE)
+		printk("x\n");
+#endif
+
+	info->tr_descr.sw_len = 0;
+	info->tr_descr.hw_len = 0;
+	info->tr_descr.status = 0;
+	info->tr_running = 1;
+	if (info->uses_dma_out)
+		transmit_chars_dma(info);
+	else
+		e100_enable_serial_tx_ready_irq(info);
+} /* start_transmit */
+
+#ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
+static int serial_fast_timer_started = 0;
+static int serial_fast_timer_expired = 0;
+static void flush_timeout_function(unsigned long data);
+#define START_FLUSH_FAST_TIMER_TIME(info, string, usec) {\
+  unsigned long timer_flags; \
+  local_irq_save(timer_flags); \
+  if (fast_timers[info->line].function == NULL) { \
+    serial_fast_timer_started++; \
+    TIMERD(DEBUG_LOG(info->line, "start_timer %i ", info->line)); \
+    TIMERD(DEBUG_LOG(info->line, "num started: %i\n", serial_fast_timer_started)); \
+    start_one_shot_timer(&fast_timers[info->line], \
+                         flush_timeout_function, \
+                         (unsigned long)info, \
+                         (usec), \
+                         string); \
+  } \
+  else { \
+    TIMERD(DEBUG_LOG(info->line, "timer %i already running\n", info->line)); \
+  } \
+  local_irq_restore(timer_flags); \
+}
+#define START_FLUSH_FAST_TIMER(info, string) START_FLUSH_FAST_TIMER_TIME(info, string, info->flush_time_usec)
+
+#else
+#define START_FLUSH_FAST_TIMER_TIME(info, string, usec)
+#define START_FLUSH_FAST_TIMER(info, string)
+#endif
+
+static struct etrax_recv_buffer *
+alloc_recv_buffer(unsigned int size)
+{
+	struct etrax_recv_buffer *buffer;
+
+	if (!(buffer = kmalloc(sizeof *buffer + size, GFP_ATOMIC)))
+		return NULL;
+
+	buffer->next = NULL;
+	buffer->length = 0;
+	buffer->error = TTY_NORMAL;
+
+	return buffer;
+}
+
+static void
+append_recv_buffer(struct e100_serial *info, struct etrax_recv_buffer *buffer)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	if (!info->first_recv_buffer)
+		info->first_recv_buffer = buffer;
+	else
+		info->last_recv_buffer->next = buffer;
+
+	info->last_recv_buffer = buffer;
+
+	info->recv_cnt += buffer->length;
+	if (info->recv_cnt > info->max_recv_cnt)
+		info->max_recv_cnt = info->recv_cnt;
+
+	local_irq_restore(flags);
+}
+
+static int
+add_char_and_flag(struct e100_serial *info, unsigned char data, unsigned char flag)
+{
+	struct etrax_recv_buffer *buffer;
+	if (info->uses_dma_in) {
+		if (!(buffer = alloc_recv_buffer(4)))
+			return 0;
+
+		buffer->length = 1;
+		buffer->error = flag;
+		buffer->buffer[0] = data;
+
+		append_recv_buffer(info, buffer);
+
+		info->icount.rx++;
+	} else {
+		struct tty_struct *tty = info->port.tty;
+		tty_insert_flip_char(tty, data, flag);
+		info->icount.rx++;
+	}
+
+	return 1;
+}
+
+static unsigned int handle_descr_data(struct e100_serial *info,
+				      struct etrax_dma_descr *descr,
+				      unsigned int recvl)
+{
+	struct etrax_recv_buffer *buffer = phys_to_virt(descr->buf) - sizeof *buffer;
+
+	if (info->recv_cnt + recvl > 65536) {
+		printk(KERN_CRIT
+		       "%s: Too much pending incoming serial data! Dropping %u bytes.\n", __func__, recvl);
+		return 0;
+	}
+
+	buffer->length = recvl;
+
+	if (info->errorcode == ERRCODE_SET_BREAK)
+		buffer->error = TTY_BREAK;
+	info->errorcode = 0;
+
+	append_recv_buffer(info, buffer);
+
+	if (!(buffer = alloc_recv_buffer(SERIAL_DESCR_BUF_SIZE)))
+		panic("%s: Failed to allocate memory for receive buffer!\n", __func__);
+
+	descr->buf = virt_to_phys(buffer->buffer);
+
+	return recvl;
+}
+
+static unsigned int handle_all_descr_data(struct e100_serial *info)
+{
+	struct etrax_dma_descr *descr;
+	unsigned int recvl;
+	unsigned int ret = 0;
+
+	while (1)
+	{
+		descr = &info->rec_descr[info->cur_rec_descr];
+
+		if (descr == phys_to_virt(*info->idescradr))
+			break;
+
+		if (++info->cur_rec_descr == SERIAL_RECV_DESCRIPTORS)
+			info->cur_rec_descr = 0;
+
+		/* find out how many bytes were read */
+
+		/* if the eop bit was not set, all data has been received */
+		if (!(descr->status & d_eop)) {
+			recvl = descr->sw_len;
+		} else {
+			/* otherwise we find the amount of data received here */
+			recvl = descr->hw_len;
+		}
+
+		/* Reset the status information */
+		descr->status = 0;
+
+		DFLOW(  DEBUG_LOG(info->line, "RX %lu\n", recvl);
+			if (info->port.tty->stopped) {
+				unsigned char *buf = phys_to_virt(descr->buf);
+				DEBUG_LOG(info->line, "rx 0x%02X\n", buf[0]);
+				DEBUG_LOG(info->line, "rx 0x%02X\n", buf[1]);
+				DEBUG_LOG(info->line, "rx 0x%02X\n", buf[2]);
+			}
+			);
+
+		/* update stats */
+		info->icount.rx += recvl;
+
+		ret += handle_descr_data(info, descr, recvl);
+	}
+
+	return ret;
+}
+
+static void receive_chars_dma(struct e100_serial *info)
+{
+	struct tty_struct *tty;
+	unsigned char rstat;
+
+#ifdef CONFIG_SVINTO_SIM
+	/* No receive in the simulator.  Will probably be when the rest of
+	 * the serial interface works, and this piece will just be removed.
+	 */
+	return;
+#endif
+
+	/* Acknowledge both dma_descr and dma_eop irq in R_DMA_CHx_CLR_INTR */
+	*info->iclrintradr =
+		IO_STATE(R_DMA_CH6_CLR_INTR, clr_descr, do) |
+		IO_STATE(R_DMA_CH6_CLR_INTR, clr_eop, do);
+
+	tty = info->port.tty;
+	if (!tty) /* Something wrong... */
+		return;
+
+#ifdef SERIAL_HANDLE_EARLY_ERRORS
+	if (info->uses_dma_in)
+		e100_enable_serial_data_irq(info);
+#endif
+
+	if (info->errorcode == ERRCODE_INSERT_BREAK)
+		add_char_and_flag(info, '\0', TTY_BREAK);
+
+	handle_all_descr_data(info);
+
+	/* Read the status register to detect errors */
+	rstat = info->ioport[REG_STATUS];
+	if (rstat & IO_MASK(R_SERIAL0_STATUS, xoff_detect) ) {
+		DFLOW(DEBUG_LOG(info->line, "XOFF detect stat %x\n", rstat));
+	}
+
+	if (rstat & SER_ERROR_MASK) {
+		/* If we got an error, we must reset it by reading the
+		 * data_in field
+		 */
+		unsigned char data = info->ioport[REG_DATA];
+
+		PROCSTAT(ser_stat[info->line].errors_cnt++);
+		DEBUG_LOG(info->line, "#dERR: s d 0x%04X\n",
+			  ((rstat & SER_ERROR_MASK) << 8) | data);
+
+		if (rstat & SER_PAR_ERR_MASK)
+			add_char_and_flag(info, data, TTY_PARITY);
+		else if (rstat & SER_OVERRUN_MASK)
+			add_char_and_flag(info, data, TTY_OVERRUN);
+		else if (rstat & SER_FRAMING_ERR_MASK)
+			add_char_and_flag(info, data, TTY_FRAME);
+	}
+
+	START_FLUSH_FAST_TIMER(info, "receive_chars");
+
+	/* Restart the receiving DMA */
+	*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, restart);
+}
+
+static int start_recv_dma(struct e100_serial *info)
+{
+	struct etrax_dma_descr *descr = info->rec_descr;
+	struct etrax_recv_buffer *buffer;
+        int i;
+
+	/* Set up the receiving descriptors */
+	for (i = 0; i < SERIAL_RECV_DESCRIPTORS; i++) {
+		if (!(buffer = alloc_recv_buffer(SERIAL_DESCR_BUF_SIZE)))
+			panic("%s: Failed to allocate memory for receive buffer!\n", __func__);
+
+		descr[i].ctrl = d_int;
+		descr[i].buf = virt_to_phys(buffer->buffer);
+		descr[i].sw_len = SERIAL_DESCR_BUF_SIZE;
+		descr[i].hw_len = 0;
+		descr[i].status = 0;
+		descr[i].next = virt_to_phys(&descr[i+1]);
+	}
+
+	/* Link the last descriptor to the first */
+	descr[i-1].next = virt_to_phys(&descr[0]);
+
+	/* Start with the first descriptor in the list */
+	info->cur_rec_descr = 0;
+
+	/* Start the DMA */
+	*info->ifirstadr = virt_to_phys(&descr[info->cur_rec_descr]);
+	*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, start);
+
+	/* Input DMA should be running now */
+	return 1;
+}
+
+static void
+start_receive(struct e100_serial *info)
+{
+#ifdef CONFIG_SVINTO_SIM
+	/* No receive in the simulator.  Will probably be when the rest of
+	 * the serial interface works, and this piece will just be removed.
+	 */
+	return;
+#endif
+	if (info->uses_dma_in) {
+		/* reset the input dma channel to be sure it works */
+
+		*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
+		while (IO_EXTRACT(R_DMA_CH6_CMD, cmd, *info->icmdadr) ==
+		       IO_STATE_VALUE(R_DMA_CH6_CMD, cmd, reset));
+
+		start_recv_dma(info);
+	}
+}
+
+
+/* the bits in the MASK2 register are laid out like this:
+   DMAI_EOP DMAI_DESCR DMAO_EOP DMAO_DESCR
+   where I is the input channel and O is the output channel for the port.
+   info->irq is the bit number for the DMAO_DESCR so to check the others we
+   shift info->irq to the left.
+*/
+
+/* dma output channel interrupt handler
+   this interrupt is called from DMA2(ser2), DMA4(ser3), DMA6(ser0) or
+   DMA8(ser1) when they have finished a descriptor with the intr flag set.
+*/
+
+static irqreturn_t
+tr_interrupt(int irq, void *dev_id)
+{
+	struct e100_serial *info;
+	unsigned long ireg;
+	int i;
+	int handled = 0;
+
+#ifdef CONFIG_SVINTO_SIM
+	/* No receive in the simulator.  Will probably be when the rest of
+	 * the serial interface works, and this piece will just be removed.
+	 */
+	{
+		const char *s = "What? tr_interrupt in simulator??\n";
+		SIMCOUT(s,strlen(s));
+	}
+	return IRQ_HANDLED;
+#endif
+
+	/* find out the line that caused this irq and get it from rs_table */
+
+	ireg = *R_IRQ_MASK2_RD;  /* get the active irq bits for the dma channels */
+
+	for (i = 0; i < NR_PORTS; i++) {
+		info = rs_table + i;
+		if (!info->enabled || !info->uses_dma_out)
+			continue;
+		/* check for dma_descr (don't need to check for dma_eop in output dma for serial */
+		if (ireg & info->irq) {
+			handled = 1;
+			/* we can send a new dma bunch. make it so. */
+			DINTR2(DEBUG_LOG(info->line, "tr_interrupt %i\n", i));
+			/* Read jiffies_usec first,
+			 * we want this time to be as late as possible
+			 */
+ 			PROCSTAT(ser_stat[info->line].tx_dma_ints++);
+			info->last_tx_active_usec = GET_JIFFIES_USEC();
+			info->last_tx_active = jiffies;
+			transmit_chars_dma(info);
+		}
+
+		/* FIXME: here we should really check for a change in the
+		   status lines and if so call status_handle(info) */
+	}
+	return IRQ_RETVAL(handled);
+} /* tr_interrupt */
+
+/* dma input channel interrupt handler */
+
+static irqreturn_t
+rec_interrupt(int irq, void *dev_id)
+{
+	struct e100_serial *info;
+	unsigned long ireg;
+	int i;
+	int handled = 0;
+
+#ifdef CONFIG_SVINTO_SIM
+	/* No receive in the simulator.  Will probably be when the rest of
+	 * the serial interface works, and this piece will just be removed.
+	 */
+	{
+		const char *s = "What? rec_interrupt in simulator??\n";
+		SIMCOUT(s,strlen(s));
+	}
+	return IRQ_HANDLED;
+#endif
+
+	/* find out the line that caused this irq and get it from rs_table */
+
+	ireg = *R_IRQ_MASK2_RD;  /* get the active irq bits for the dma channels */
+
+	for (i = 0; i < NR_PORTS; i++) {
+		info = rs_table + i;
+		if (!info->enabled || !info->uses_dma_in)
+			continue;
+		/* check for both dma_eop and dma_descr for the input dma channel */
+		if (ireg & ((info->irq << 2) | (info->irq << 3))) {
+			handled = 1;
+			/* we have received something */
+			receive_chars_dma(info);
+		}
+
+		/* FIXME: here we should really check for a change in the
+		   status lines and if so call status_handle(info) */
+	}
+	return IRQ_RETVAL(handled);
+} /* rec_interrupt */
+
+static int force_eop_if_needed(struct e100_serial *info)
+{
+	/* We check data_avail bit to determine if data has
+	 * arrived since last time
+	 */
+	unsigned char rstat = info->ioport[REG_STATUS];
+
+	/* error or datavail? */
+	if (rstat & SER_ERROR_MASK) {
+		/* Some error has occurred. If there has been valid data, an
+		 * EOP interrupt will be made automatically. If no data, the
+		 * normal ser_interrupt should be enabled and handle it.
+		 * So do nothing!
+		 */
+		DEBUG_LOG(info->line, "timeout err: rstat 0x%03X\n",
+		          rstat | (info->line << 8));
+		return 0;
+	}
+
+	if (rstat & SER_DATA_AVAIL_MASK) {
+		/* Ok data, no error, count it */
+		TIMERD(DEBUG_LOG(info->line, "timeout: rstat 0x%03X\n",
+		          rstat | (info->line << 8)));
+		/* Read data to clear status flags */
+		(void)info->ioport[REG_DATA];
+
+		info->forced_eop = 0;
+		START_FLUSH_FAST_TIMER(info, "magic");
+		return 0;
+	}
+
+	/* hit the timeout, force an EOP for the input
+	 * dma channel if we haven't already
+	 */
+	if (!info->forced_eop) {
+		info->forced_eop = 1;
+		PROCSTAT(ser_stat[info->line].timeout_flush_cnt++);
+		TIMERD(DEBUG_LOG(info->line, "timeout EOP %i\n", info->line));
+		FORCE_EOP(info);
+	}
+
+	return 1;
+}
+
+static void flush_to_flip_buffer(struct e100_serial *info)
+{
+	struct tty_struct *tty;
+	struct etrax_recv_buffer *buffer;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	tty = info->port.tty;
+
+	if (!tty) {
+		local_irq_restore(flags);
+		return;
+	}
+
+	while ((buffer = info->first_recv_buffer) != NULL) {
+		unsigned int count = buffer->length;
+
+		tty_insert_flip_string(tty, buffer->buffer, count);
+		info->recv_cnt -= count;
+
+		if (count == buffer->length) {
+			info->first_recv_buffer = buffer->next;
+			kfree(buffer);
+		} else {
+			buffer->length -= count;
+			memmove(buffer->buffer, buffer->buffer + count, buffer->length);
+			buffer->error = TTY_NORMAL;
+		}
+	}
+
+	if (!info->first_recv_buffer)
+		info->last_recv_buffer = NULL;
+
+	local_irq_restore(flags);
+
+	/* This includes a check for low-latency */
+	tty_flip_buffer_push(tty);
+}
+
+static void check_flush_timeout(struct e100_serial *info)
+{
+	/* Flip what we've got (if we can) */
+	flush_to_flip_buffer(info);
+
+	/* We might need to flip later, but not to fast
+	 * since the system is busy processing input... */
+	if (info->first_recv_buffer)
+		START_FLUSH_FAST_TIMER_TIME(info, "flip", 2000);
+
+	/* Force eop last, since data might have come while we're processing
+	 * and if we started the slow timer above, we won't start a fast
+	 * below.
+	 */
+	force_eop_if_needed(info);
+}
+
+#ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
+static void flush_timeout_function(unsigned long data)
+{
+	struct e100_serial *info = (struct e100_serial *)data;
+
+	fast_timers[info->line].function = NULL;
+	serial_fast_timer_expired++;
+	TIMERD(DEBUG_LOG(info->line, "flush_timout %i ", info->line));
+	TIMERD(DEBUG_LOG(info->line, "num expired: %i\n", serial_fast_timer_expired));
+	check_flush_timeout(info);
+}
+
+#else
+
+/* dma fifo/buffer timeout handler
+   forces an end-of-packet for the dma input channel if no chars
+   have been received for CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS/100 s.
+*/
+
+static struct timer_list flush_timer;
+
+static void
+timed_flush_handler(unsigned long ptr)
+{
+	struct e100_serial *info;
+	int i;
+
+#ifdef CONFIG_SVINTO_SIM
+	return;
+#endif
+
+	for (i = 0; i < NR_PORTS; i++) {
+		info = rs_table + i;
+		if (info->uses_dma_in)
+			check_flush_timeout(info);
+	}
+
+	/* restart flush timer */
+	mod_timer(&flush_timer, jiffies + CONFIG_ETRAX_SERIAL_RX_TIMEOUT_TICKS);
+}
+#endif
+
+#ifdef SERIAL_HANDLE_EARLY_ERRORS
+
+/* If there is an error (ie break) when the DMA is running and
+ * there are no bytes in the fifo the DMA is stopped and we get no
+ * eop interrupt. Thus we have to monitor the first bytes on a DMA
+ * transfer, and if it is without error we can turn the serial
+ * interrupts off.
+ */
+
+/*
+BREAK handling on ETRAX 100:
+ETRAX will generate interrupt although there is no stop bit between the
+characters.
+
+Depending on how long the break sequence is, the end of the breaksequence
+will look differently:
+| indicates start/end of a character.
+
+B= Break character (0x00) with framing error.
+E= Error byte with parity error received after B characters.
+F= "Faked" valid byte received immediately after B characters.
+V= Valid byte
+
+1.
+    B          BL         ___________________________ V
+.._|__________|__________|                           |valid data |
+
+Multiple frame errors with data == 0x00 (B),
+the timing matches up "perfectly" so no extra ending char is detected.
+The RXD pin is 1 in the last interrupt, in that case
+we set info->errorcode = ERRCODE_INSERT_BREAK, but we can't really
+know if another byte will come and this really is case 2. below
+(e.g F=0xFF or 0xFE)
+If RXD pin is 0 we can expect another character (see 2. below).
+
+
+2.
+
+    B          B          E or F__________________..__ V
+.._|__________|__________|______    |                 |valid data
+                          "valid" or
+                          parity error
+
+Multiple frame errors with data == 0x00 (B),
+but the part of the break trigs is interpreted as a start bit (and possibly
+some 0 bits followed by a number of 1 bits and a stop bit).
+Depending on parity settings etc. this last character can be either
+a fake "valid" char (F) or have a parity error (E).
+
+If the character is valid it will be put in the buffer,
+we set info->errorcode = ERRCODE_SET_BREAK so the receive interrupt
+will set the flags so the tty will handle it,
+if it's an error byte it will not be put in the buffer
+and we set info->errorcode = ERRCODE_INSERT_BREAK.
+
+To distinguish a V byte in 1. from an F byte in 2. we keep a timestamp
+of the last faulty char (B) and compares it with the current time:
+If the time elapsed time is less then 2*char_time_usec we will assume
+it's a faked F char and not a Valid char and set
+info->errorcode = ERRCODE_SET_BREAK.
+
+Flaws in the above solution:
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+We use the timer to distinguish a F character from a V character,
+if a V character is to close after the break we might make the wrong decision.
+
+TODO: The break will be delayed until an F or V character is received.
+
+*/
+
+static
+struct e100_serial * handle_ser_rx_interrupt_no_dma(struct e100_serial *info)
+{
+	unsigned long data_read;
+	struct tty_struct *tty = info->port.tty;
+
+	if (!tty) {
+		printk("!NO TTY!\n");
+		return info;
+	}
+
+	/* Read data and status at the same time */
+	data_read = *((unsigned long *)&info->ioport[REG_DATA_STATUS32]);
+more_data:
+	if (data_read & IO_MASK(R_SERIAL0_READ, xoff_detect) ) {
+		DFLOW(DEBUG_LOG(info->line, "XOFF detect\n", 0));
+	}
+	DINTR2(DEBUG_LOG(info->line, "ser_rx   %c\n", IO_EXTRACT(R_SERIAL0_READ, data_in, data_read)));
+
+	if (data_read & ( IO_MASK(R_SERIAL0_READ, framing_err) |
+			  IO_MASK(R_SERIAL0_READ, par_err) |
+			  IO_MASK(R_SERIAL0_READ, overrun) )) {
+		/* An error */
+		info->last_rx_active_usec = GET_JIFFIES_USEC();
+		info->last_rx_active = jiffies;
+		DINTR1(DEBUG_LOG(info->line, "ser_rx err stat_data %04X\n", data_read));
+		DLOG_INT_TRIG(
+		if (!log_int_trig1_pos) {
+			log_int_trig1_pos = log_int_pos;
+			log_int(rdpc(), 0, 0);
+		}
+		);
+
+
+		if ( ((data_read & IO_MASK(R_SERIAL0_READ, data_in)) == 0) &&
+		     (data_read & IO_MASK(R_SERIAL0_READ, framing_err)) ) {
+			/* Most likely a break, but we get interrupts over and
+			 * over again.
+			 */
+
+			if (!info->break_detected_cnt) {
+				DEBUG_LOG(info->line, "#BRK start\n", 0);
+			}
+			if (data_read & IO_MASK(R_SERIAL0_READ, rxd)) {
+				/* The RX pin is high now, so the break
+				 * must be over, but....
+				 * we can't really know if we will get another
+				 * last byte ending the break or not.
+				 * And we don't know if the byte (if any) will
+				 * have an error or look valid.
+				 */
+				DEBUG_LOG(info->line, "# BL BRK\n", 0);
+				info->errorcode = ERRCODE_INSERT_BREAK;
+			}
+			info->break_detected_cnt++;
+		} else {
+			/* The error does not look like a break, but could be
+			 * the end of one
+			 */
+			if (info->break_detected_cnt) {
+				DEBUG_LOG(info->line, "EBRK %i\n", info->break_detected_cnt);
+				info->errorcode = ERRCODE_INSERT_BREAK;
+			} else {
+				unsigned char data = IO_EXTRACT(R_SERIAL0_READ,
+					data_in, data_read);
+				char flag = TTY_NORMAL;
+				if (info->errorcode == ERRCODE_INSERT_BREAK) {
+					struct tty_struct *tty = info->port.tty;
+					tty_insert_flip_char(tty, 0, flag);
+					info->icount.rx++;
+				}
+
+				if (data_read & IO_MASK(R_SERIAL0_READ, par_err)) {
+					info->icount.parity++;
+					flag = TTY_PARITY;
+				} else if (data_read & IO_MASK(R_SERIAL0_READ, overrun)) {
+					info->icount.overrun++;
+					flag = TTY_OVERRUN;
+				} else if (data_read & IO_MASK(R_SERIAL0_READ, framing_err)) {
+					info->icount.frame++;
+					flag = TTY_FRAME;
+				}
+				tty_insert_flip_char(tty, data, flag);
+				info->errorcode = 0;
+			}
+			info->break_detected_cnt = 0;
+		}
+	} else if (data_read & IO_MASK(R_SERIAL0_READ, data_avail)) {
+		/* No error */
+		DLOG_INT_TRIG(
+		if (!log_int_trig1_pos) {
+			if (log_int_pos >= log_int_size) {
+				log_int_pos = 0;
+			}
+			log_int_trig0_pos = log_int_pos;
+			log_int(rdpc(), 0, 0);
+		}
+		);
+		tty_insert_flip_char(tty,
+			IO_EXTRACT(R_SERIAL0_READ, data_in, data_read),
+			TTY_NORMAL);
+	} else {
+		DEBUG_LOG(info->line, "ser_rx int but no data_avail  %08lX\n", data_read);
+	}
+
+
+	info->icount.rx++;
+	data_read = *((unsigned long *)&info->ioport[REG_DATA_STATUS32]);
+	if (data_read & IO_MASK(R_SERIAL0_READ, data_avail)) {
+		DEBUG_LOG(info->line, "ser_rx   %c in loop\n", IO_EXTRACT(R_SERIAL0_READ, data_in, data_read));
+		goto more_data;
+	}
+
+	tty_flip_buffer_push(info->port.tty);
+	return info;
+}
+
+static struct e100_serial* handle_ser_rx_interrupt(struct e100_serial *info)
+{
+	unsigned char rstat;
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("Interrupt from serport %d\n", i);
+#endif
+/*	DEBUG_LOG(info->line, "ser_interrupt stat %03X\n", rstat | (i << 8)); */
+	if (!info->uses_dma_in) {
+		return handle_ser_rx_interrupt_no_dma(info);
+	}
+	/* DMA is used */
+	rstat = info->ioport[REG_STATUS];
+	if (rstat & IO_MASK(R_SERIAL0_STATUS, xoff_detect) ) {
+		DFLOW(DEBUG_LOG(info->line, "XOFF detect\n", 0));
+	}
+
+	if (rstat & SER_ERROR_MASK) {
+		unsigned char data;
+
+		info->last_rx_active_usec = GET_JIFFIES_USEC();
+		info->last_rx_active = jiffies;
+		/* If we got an error, we must reset it by reading the
+		 * data_in field
+		 */
+		data = info->ioport[REG_DATA];
+		DINTR1(DEBUG_LOG(info->line, "ser_rx!  %c\n", data));
+		DINTR1(DEBUG_LOG(info->line, "ser_rx err stat %02X\n", rstat));
+		if (!data && (rstat & SER_FRAMING_ERR_MASK)) {
+			/* Most likely a break, but we get interrupts over and
+			 * over again.
+			 */
+
+			if (!info->break_detected_cnt) {
+				DEBUG_LOG(info->line, "#BRK start\n", 0);
+			}
+			if (rstat & SER_RXD_MASK) {
+				/* The RX pin is high now, so the break
+				 * must be over, but....
+				 * we can't really know if we will get another
+				 * last byte ending the break or not.
+				 * And we don't know if the byte (if any) will
+				 * have an error or look valid.
+				 */
+				DEBUG_LOG(info->line, "# BL BRK\n", 0);
+				info->errorcode = ERRCODE_INSERT_BREAK;
+			}
+			info->break_detected_cnt++;
+		} else {
+			/* The error does not look like a break, but could be
+			 * the end of one
+			 */
+			if (info->break_detected_cnt) {
+				DEBUG_LOG(info->line, "EBRK %i\n", info->break_detected_cnt);
+				info->errorcode = ERRCODE_INSERT_BREAK;
+			} else {
+				if (info->errorcode == ERRCODE_INSERT_BREAK) {
+					info->icount.brk++;
+					add_char_and_flag(info, '\0', TTY_BREAK);
+				}
+
+				if (rstat & SER_PAR_ERR_MASK) {
+					info->icount.parity++;
+					add_char_and_flag(info, data, TTY_PARITY);
+				} else if (rstat & SER_OVERRUN_MASK) {
+					info->icount.overrun++;
+					add_char_and_flag(info, data, TTY_OVERRUN);
+				} else if (rstat & SER_FRAMING_ERR_MASK) {
+					info->icount.frame++;
+					add_char_and_flag(info, data, TTY_FRAME);
+				}
+
+				info->errorcode = 0;
+			}
+			info->break_detected_cnt = 0;
+			DEBUG_LOG(info->line, "#iERR s d %04X\n",
+			          ((rstat & SER_ERROR_MASK) << 8) | data);
+		}
+		PROCSTAT(ser_stat[info->line].early_errors_cnt++);
+	} else { /* It was a valid byte, now let the DMA do the rest */
+		unsigned long curr_time_u = GET_JIFFIES_USEC();
+		unsigned long curr_time = jiffies;
+
+		if (info->break_detected_cnt) {
+			/* Detect if this character is a new valid char or the
+			 * last char in a break sequence: If LSBits are 0 and
+			 * MSBits are high AND the time is close to the
+			 * previous interrupt we should discard it.
+			 */
+			long elapsed_usec =
+			  (curr_time - info->last_rx_active) * (1000000/HZ) +
+			  curr_time_u - info->last_rx_active_usec;
+			if (elapsed_usec < 2*info->char_time_usec) {
+				DEBUG_LOG(info->line, "FBRK %i\n", info->line);
+				/* Report as BREAK (error) and let
+				 * receive_chars_dma() handle it
+				 */
+				info->errorcode = ERRCODE_SET_BREAK;
+			} else {
+				DEBUG_LOG(info->line, "Not end of BRK (V)%i\n", info->line);
+			}
+			DEBUG_LOG(info->line, "num brk %i\n", info->break_detected_cnt);
+		}
+
+#ifdef SERIAL_DEBUG_INTR
+		printk("** OK, disabling ser_interrupts\n");
+#endif
+		e100_disable_serial_data_irq(info);
+		DINTR2(DEBUG_LOG(info->line, "ser_rx OK %d\n", info->line));
+		info->break_detected_cnt = 0;
+
+		PROCSTAT(ser_stat[info->line].ser_ints_ok_cnt++);
+	}
+	/* Restarting the DMA never hurts */
+	*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, restart);
+	START_FLUSH_FAST_TIMER(info, "ser_int");
+	return info;
+} /* handle_ser_rx_interrupt */
+
+static void handle_ser_tx_interrupt(struct e100_serial *info)
+{
+	unsigned long flags;
+
+	if (info->x_char) {
+		unsigned char rstat;
+		DFLOW(DEBUG_LOG(info->line, "tx_int: xchar 0x%02X\n", info->x_char));
+		local_irq_save(flags);
+		rstat = info->ioport[REG_STATUS];
+		DFLOW(DEBUG_LOG(info->line, "stat %x\n", rstat));
+
+		info->ioport[REG_TR_DATA] = info->x_char;
+		info->icount.tx++;
+		info->x_char = 0;
+		/* We must enable since it is disabled in ser_interrupt */
+		e100_enable_serial_tx_ready_irq(info);
+		local_irq_restore(flags);
+		return;
+	}
+	if (info->uses_dma_out) {
+		unsigned char rstat;
+		int i;
+		/* We only use normal tx interrupt when sending x_char */
+		DFLOW(DEBUG_LOG(info->line, "tx_int: xchar sent\n", 0));
+		local_irq_save(flags);
+		rstat = info->ioport[REG_STATUS];
+		DFLOW(DEBUG_LOG(info->line, "stat %x\n", rstat));
+		e100_disable_serial_tx_ready_irq(info);
+		if (info->port.tty->stopped)
+			rs_stop(info->port.tty);
+		/* Enable the DMA channel and tell it to continue */
+		e100_enable_txdma_channel(info);
+		/* Wait 12 cycles before doing the DMA command */
+		for(i = 6;  i > 0; i--)
+			nop();
+
+		*info->ocmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, continue);
+		local_irq_restore(flags);
+		return;
+	}
+	/* Normal char-by-char interrupt */
+	if (info->xmit.head == info->xmit.tail
+	    || info->port.tty->stopped
+	    || info->port.tty->hw_stopped) {
+		DFLOW(DEBUG_LOG(info->line, "tx_int: stopped %i\n",
+				info->port.tty->stopped));
+		e100_disable_serial_tx_ready_irq(info);
+		info->tr_running = 0;
+		return;
+	}
+	DINTR2(DEBUG_LOG(info->line, "tx_int %c\n", info->xmit.buf[info->xmit.tail]));
+	/* Send a byte, rs485 timing is critical so turn of ints */
+	local_irq_save(flags);
+	info->ioport[REG_TR_DATA] = info->xmit.buf[info->xmit.tail];
+	info->xmit.tail = (info->xmit.tail + 1) & (SERIAL_XMIT_SIZE-1);
+	info->icount.tx++;
+	if (info->xmit.head == info->xmit.tail) {
+#if defined(CONFIG_ETRAX_RS485) && defined(CONFIG_ETRAX_FAST_TIMER)
+		if (info->rs485.flags & SER_RS485_ENABLED) {
+			/* Set a short timer to toggle RTS */
+			start_one_shot_timer(&fast_timers_rs485[info->line],
+			                     rs485_toggle_rts_timer_function,
+			                     (unsigned long)info,
+			                     info->char_time_usec*2,
+			                     "RS-485");
+		}
+#endif /* RS485 */
+		info->last_tx_active_usec = GET_JIFFIES_USEC();
+		info->last_tx_active = jiffies;
+		e100_disable_serial_tx_ready_irq(info);
+		info->tr_running = 0;
+		DFLOW(DEBUG_LOG(info->line, "tx_int: stop2\n", 0));
+	} else {
+		/* We must enable since it is disabled in ser_interrupt */
+		e100_enable_serial_tx_ready_irq(info);
+	}
+	local_irq_restore(flags);
+
+	if (CIRC_CNT(info->xmit.head,
+		     info->xmit.tail,
+		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
+		rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
+
+} /* handle_ser_tx_interrupt */
+
+/* result of time measurements:
+ * RX duration 54-60 us when doing something, otherwise 6-9 us
+ * ser_int duration: just sending: 8-15 us normally, up to 73 us
+ */
+static irqreturn_t
+ser_interrupt(int irq, void *dev_id)
+{
+	static volatile int tx_started = 0;
+	struct e100_serial *info;
+	int i;
+	unsigned long flags;
+	unsigned long irq_mask1_rd;
+	unsigned long data_mask = (1 << (8+2*0)); /* ser0 data_avail */
+	int handled = 0;
+	static volatile unsigned long reentered_ready_mask = 0;
+
+	local_irq_save(flags);
+	irq_mask1_rd = *R_IRQ_MASK1_RD;
+	/* First handle all rx interrupts with ints disabled */
+	info = rs_table;
+	irq_mask1_rd &= e100_ser_int_mask;
+	for (i = 0; i < NR_PORTS; i++) {
+		/* Which line caused the data irq? */
+		if (irq_mask1_rd & data_mask) {
+			handled = 1;
+			handle_ser_rx_interrupt(info);
+		}
+		info += 1;
+		data_mask <<= 2;
+	}
+	/* Handle tx interrupts with interrupts enabled so we
+	 * can take care of new data interrupts while transmitting
+	 * We protect the tx part with the tx_started flag.
+	 * We disable the tr_ready interrupts we are about to handle and
+	 * unblock the serial interrupt so new serial interrupts may come.
+	 *
+	 * If we get a new interrupt:
+	 *  - it migth be due to synchronous serial ports.
+	 *  - serial irq will be blocked by general irq handler.
+	 *  - async data will be handled above (sync will be ignored).
+	 *  - tx_started flag will prevent us from trying to send again and
+	 *    we will exit fast - no need to unblock serial irq.
+	 *  - Next (sync) serial interrupt handler will be runned with
+	 *    disabled interrupt due to restore_flags() at end of function,
+	 *    so sync handler will not be preempted or reentered.
+	 */
+	if (!tx_started) {
+		unsigned long ready_mask;
+		unsigned long
+		tx_started = 1;
+		/* Only the tr_ready interrupts left */
+		irq_mask1_rd &= (IO_MASK(R_IRQ_MASK1_RD, ser0_ready) |
+				 IO_MASK(R_IRQ_MASK1_RD, ser1_ready) |
+				 IO_MASK(R_IRQ_MASK1_RD, ser2_ready) |
+				 IO_MASK(R_IRQ_MASK1_RD, ser3_ready));
+		while (irq_mask1_rd) {
+			/* Disable those we are about to handle */
+			*R_IRQ_MASK1_CLR = irq_mask1_rd;
+			/* Unblock the serial interrupt */
+			*R_VECT_MASK_SET = IO_STATE(R_VECT_MASK_SET, serial, set);
+
+			local_irq_enable();
+			ready_mask = (1 << (8+1+2*0)); /* ser0 tr_ready */
+			info = rs_table;
+			for (i = 0; i < NR_PORTS; i++) {
+				/* Which line caused the ready irq? */
+				if (irq_mask1_rd & ready_mask) {
+					handled = 1;
+					handle_ser_tx_interrupt(info);
+				}
+				info += 1;
+				ready_mask <<= 2;
+			}
+			/* handle_ser_tx_interrupt enables tr_ready interrupts */
+			local_irq_disable();
+			/* Handle reentered TX interrupt */
+			irq_mask1_rd = reentered_ready_mask;
+		}
+		local_irq_disable();
+		tx_started = 0;
+	} else {
+		unsigned long ready_mask;
+		ready_mask = irq_mask1_rd & (IO_MASK(R_IRQ_MASK1_RD, ser0_ready) |
+					     IO_MASK(R_IRQ_MASK1_RD, ser1_ready) |
+					     IO_MASK(R_IRQ_MASK1_RD, ser2_ready) |
+					     IO_MASK(R_IRQ_MASK1_RD, ser3_ready));
+		if (ready_mask) {
+			reentered_ready_mask |= ready_mask;
+			/* Disable those we are about to handle */
+			*R_IRQ_MASK1_CLR = ready_mask;
+			DFLOW(DEBUG_LOG(SERIAL_DEBUG_LINE, "ser_int reentered with TX %X\n", ready_mask));
+		}
+	}
+
+	local_irq_restore(flags);
+	return IRQ_RETVAL(handled);
+} /* ser_interrupt */
+#endif
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+/*
+ * This routine is used to handle the "bottom half" processing for the
+ * serial driver, known also the "software interrupt" processing.
+ * This processing is done at the kernel interrupt level, after the
+ * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
+ * is where time-consuming activities which can not be done in the
+ * interrupt driver proper are done; the interrupt driver schedules
+ * them using rs_sched_event(), and they get done here.
+ */
+static void
+do_softint(struct work_struct *work)
+{
+	struct e100_serial	*info;
+	struct tty_struct	*tty;
+
+	info = container_of(work, struct e100_serial, work);
+
+	tty = info->port.tty;
+	if (!tty)
+		return;
+
+	if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
+		tty_wakeup(tty);
+}
+
+static int
+startup(struct e100_serial * info)
+{
+	unsigned long flags;
+	unsigned long xmit_page;
+	int i;
+
+	xmit_page = get_zeroed_page(GFP_KERNEL);
+	if (!xmit_page)
+		return -ENOMEM;
+
+	local_irq_save(flags);
+
+	/* if it was already initialized, skip this */
+
+	if (info->flags & ASYNC_INITIALIZED) {
+		local_irq_restore(flags);
+		free_page(xmit_page);
+		return 0;
+	}
+
+	if (info->xmit.buf)
+		free_page(xmit_page);
+	else
+		info->xmit.buf = (unsigned char *) xmit_page;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("starting up ttyS%d (xmit_buf 0x%p)...\n", info->line, info->xmit.buf);
+#endif
+
+#ifdef CONFIG_SVINTO_SIM
+	/* Bits and pieces collected from below.  Better to have them
+	   in one ifdef:ed clause than to mix in a lot of ifdefs,
+	   right? */
+	if (info->port.tty)
+		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+
+	info->xmit.head = info->xmit.tail = 0;
+	info->first_recv_buffer = info->last_recv_buffer = NULL;
+	info->recv_cnt = info->max_recv_cnt = 0;
+
+	for (i = 0; i < SERIAL_RECV_DESCRIPTORS; i++)
+		info->rec_descr[i].buf = NULL;
+
+	/* No real action in the simulator, but may set info important
+	   to ioctl. */
+	change_speed(info);
+#else
+
+	/*
+	 * Clear the FIFO buffers and disable them
+	 * (they will be reenabled in change_speed())
+	 */
+
+	/*
+	 * Reset the DMA channels and make sure their interrupts are cleared
+	 */
+
+	if (info->dma_in_enabled) {
+		info->uses_dma_in = 1;
+		e100_enable_rxdma_channel(info);
+
+		*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
+
+		/* Wait until reset cycle is complete */
+		while (IO_EXTRACT(R_DMA_CH6_CMD, cmd, *info->icmdadr) ==
+		       IO_STATE_VALUE(R_DMA_CH6_CMD, cmd, reset));
+
+		/* Make sure the irqs are cleared */
+		*info->iclrintradr =
+			IO_STATE(R_DMA_CH6_CLR_INTR, clr_descr, do) |
+			IO_STATE(R_DMA_CH6_CLR_INTR, clr_eop, do);
+	} else {
+		e100_disable_rxdma_channel(info);
+	}
+
+	if (info->dma_out_enabled) {
+		info->uses_dma_out = 1;
+		e100_enable_txdma_channel(info);
+		*info->ocmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
+
+		while (IO_EXTRACT(R_DMA_CH6_CMD, cmd, *info->ocmdadr) ==
+		       IO_STATE_VALUE(R_DMA_CH6_CMD, cmd, reset));
+
+		/* Make sure the irqs are cleared */
+		*info->oclrintradr =
+			IO_STATE(R_DMA_CH6_CLR_INTR, clr_descr, do) |
+			IO_STATE(R_DMA_CH6_CLR_INTR, clr_eop, do);
+	} else {
+		e100_disable_txdma_channel(info);
+	}
+
+	if (info->port.tty)
+		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
+
+	info->xmit.head = info->xmit.tail = 0;
+	info->first_recv_buffer = info->last_recv_buffer = NULL;
+	info->recv_cnt = info->max_recv_cnt = 0;
+
+	for (i = 0; i < SERIAL_RECV_DESCRIPTORS; i++)
+		info->rec_descr[i].buf = 0;
+
+	/*
+	 * and set the speed and other flags of the serial port
+	 * this will start the rx/tx as well
+	 */
+#ifdef SERIAL_HANDLE_EARLY_ERRORS
+	e100_enable_serial_data_irq(info);
+#endif
+	change_speed(info);
+
+	/* dummy read to reset any serial errors */
+
+	(void)info->ioport[REG_DATA];
+
+	/* enable the interrupts */
+	if (info->uses_dma_out)
+		e100_enable_txdma_irq(info);
+
+	e100_enable_rx_irq(info);
+
+	info->tr_running = 0; /* to be sure we don't lock up the transmitter */
+
+	/* setup the dma input descriptor and start dma */
+
+	start_receive(info);
+
+	/* for safety, make sure the descriptors last result is 0 bytes written */
+
+	info->tr_descr.sw_len = 0;
+	info->tr_descr.hw_len = 0;
+	info->tr_descr.status = 0;
+
+	/* enable RTS/DTR last */
+
+	e100_rts(info, 1);
+	e100_dtr(info, 1);
+
+#endif /* CONFIG_SVINTO_SIM */
+
+	info->flags |= ASYNC_INITIALIZED;
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ */
+static void
+shutdown(struct e100_serial * info)
+{
+	unsigned long flags;
+	struct etrax_dma_descr *descr = info->rec_descr;
+	struct etrax_recv_buffer *buffer;
+	int i;
+
+#ifndef CONFIG_SVINTO_SIM
+	/* shut down the transmitter and receiver */
+	DFLOW(DEBUG_LOG(info->line, "shutdown %i\n", info->line));
+	e100_disable_rx(info);
+	info->ioport[REG_TR_CTRL] = (info->tx_ctrl &= ~0x40);
+
+	/* disable interrupts, reset dma channels */
+	if (info->uses_dma_in) {
+		e100_disable_rxdma_irq(info);
+		*info->icmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
+		info->uses_dma_in = 0;
+	} else {
+		e100_disable_serial_data_irq(info);
+	}
+
+	if (info->uses_dma_out) {
+		e100_disable_txdma_irq(info);
+		info->tr_running = 0;
+		*info->ocmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, reset);
+		info->uses_dma_out = 0;
+	} else {
+		e100_disable_serial_tx_ready_irq(info);
+		info->tr_running = 0;
+	}
+
+#endif /* CONFIG_SVINTO_SIM */
+
+	if (!(info->flags & ASYNC_INITIALIZED))
+		return;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("Shutting down serial port %d (irq %d)....\n", info->line,
+	       info->irq);
+#endif
+
+	local_irq_save(flags);
+
+	if (info->xmit.buf) {
+		free_page((unsigned long)info->xmit.buf);
+		info->xmit.buf = NULL;
+	}
+
+	for (i = 0; i < SERIAL_RECV_DESCRIPTORS; i++)
+		if (descr[i].buf) {
+			buffer = phys_to_virt(descr[i].buf) - sizeof *buffer;
+			kfree(buffer);
+			descr[i].buf = 0;
+		}
+
+	if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) {
+		/* hang up DTR and RTS if HUPCL is enabled */
+		e100_dtr(info, 0);
+		e100_rts(info, 0); /* could check CRTSCTS before doing this */
+	}
+
+	if (info->port.tty)
+		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
+
+	info->flags &= ~ASYNC_INITIALIZED;
+	local_irq_restore(flags);
+}
+
+
+/* change baud rate and other assorted parameters */
+
+static void
+change_speed(struct e100_serial *info)
+{
+	unsigned int cflag;
+	unsigned long xoff;
+	unsigned long flags;
+	/* first some safety checks */
+
+	if (!info->port.tty || !info->port.tty->termios)
+		return;
+	if (!info->ioport)
+		return;
+
+	cflag = info->port.tty->termios->c_cflag;
+
+	/* possibly, the tx/rx should be disabled first to do this safely */
+
+	/* change baud-rate and write it to the hardware */
+	if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) {
+		/* Special baudrate */
+		u32 mask = 0xFF << (info->line*8); /* Each port has 8 bits */
+		unsigned long alt_source =
+				IO_STATE(R_ALT_SER_BAUDRATE, ser0_rec, normal) |
+				IO_STATE(R_ALT_SER_BAUDRATE, ser0_tr, normal);
+		/* R_ALT_SER_BAUDRATE selects the source */
+		DBAUD(printk("Custom baudrate: baud_base/divisor %lu/%i\n",
+		       (unsigned long)info->baud_base, info->custom_divisor));
+		if (info->baud_base == SERIAL_PRESCALE_BASE) {
+			/* 0, 2-65535 (0=65536) */
+			u16 divisor = info->custom_divisor;
+			/* R_SERIAL_PRESCALE (upper 16 bits of R_CLOCK_PRESCALE) */
+			/* baudrate is 3.125MHz/custom_divisor */
+			alt_source =
+				IO_STATE(R_ALT_SER_BAUDRATE, ser0_rec, prescale) |
+				IO_STATE(R_ALT_SER_BAUDRATE, ser0_tr, prescale);
+			alt_source = 0x11;
+			DBAUD(printk("Writing SERIAL_PRESCALE: divisor %i\n", divisor));
+			*R_SERIAL_PRESCALE = divisor;
+			info->baud = SERIAL_PRESCALE_BASE/divisor;
+		}
+#ifdef CONFIG_ETRAX_EXTERN_PB6CLK_ENABLED
+		else if ((info->baud_base==CONFIG_ETRAX_EXTERN_PB6CLK_FREQ/8 &&
+			  info->custom_divisor == 1) ||
+			 (info->baud_base==CONFIG_ETRAX_EXTERN_PB6CLK_FREQ &&
+			  info->custom_divisor == 8)) {
+				/* ext_clk selected */
+				alt_source =
+					IO_STATE(R_ALT_SER_BAUDRATE, ser0_rec, extern) |
+					IO_STATE(R_ALT_SER_BAUDRATE, ser0_tr, extern);
+				DBAUD(printk("using external baudrate: %lu\n", CONFIG_ETRAX_EXTERN_PB6CLK_FREQ/8));
+				info->baud = CONFIG_ETRAX_EXTERN_PB6CLK_FREQ/8;
+			}
+#endif
+		else
+		{
+			/* Bad baudbase, we don't support using timer0
+			 * for baudrate.
+			 */
+			printk(KERN_WARNING "Bad baud_base/custom_divisor: %lu/%i\n",
+			       (unsigned long)info->baud_base, info->custom_divisor);
+		}
+		r_alt_ser_baudrate_shadow &= ~mask;
+		r_alt_ser_baudrate_shadow |= (alt_source << (info->line*8));
+		*R_ALT_SER_BAUDRATE = r_alt_ser_baudrate_shadow;
+	} else {
+		/* Normal baudrate */
+		/* Make sure we use normal baudrate */
+		u32 mask = 0xFF << (info->line*8); /* Each port has 8 bits */
+		unsigned long alt_source =
+			IO_STATE(R_ALT_SER_BAUDRATE, ser0_rec, normal) |
+			IO_STATE(R_ALT_SER_BAUDRATE, ser0_tr, normal);
+		r_alt_ser_baudrate_shadow &= ~mask;
+		r_alt_ser_baudrate_shadow |= (alt_source << (info->line*8));
+#ifndef CONFIG_SVINTO_SIM
+		*R_ALT_SER_BAUDRATE = r_alt_ser_baudrate_shadow;
+#endif /* CONFIG_SVINTO_SIM */
+
+		info->baud = cflag_to_baud(cflag);
+#ifndef CONFIG_SVINTO_SIM
+		info->ioport[REG_BAUD] = cflag_to_etrax_baud(cflag);
+#endif /* CONFIG_SVINTO_SIM */
+	}
+
+#ifndef CONFIG_SVINTO_SIM
+	/* start with default settings and then fill in changes */
+	local_irq_save(flags);
+	/* 8 bit, no/even parity */
+	info->rx_ctrl &= ~(IO_MASK(R_SERIAL0_REC_CTRL, rec_bitnr) |
+			   IO_MASK(R_SERIAL0_REC_CTRL, rec_par_en) |
+			   IO_MASK(R_SERIAL0_REC_CTRL, rec_par));
+
+	/* 8 bit, no/even parity, 1 stop bit, no cts */
+	info->tx_ctrl &= ~(IO_MASK(R_SERIAL0_TR_CTRL, tr_bitnr) |
+			   IO_MASK(R_SERIAL0_TR_CTRL, tr_par_en) |
+			   IO_MASK(R_SERIAL0_TR_CTRL, tr_par) |
+			   IO_MASK(R_SERIAL0_TR_CTRL, stop_bits) |
+			   IO_MASK(R_SERIAL0_TR_CTRL, auto_cts));
+
+	if ((cflag & CSIZE) == CS7) {
+		/* set 7 bit mode */
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, tr_bitnr, tr_7bit);
+		info->rx_ctrl |= IO_STATE(R_SERIAL0_REC_CTRL, rec_bitnr, rec_7bit);
+	}
+
+	if (cflag & CSTOPB) {
+		/* set 2 stop bit mode */
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, stop_bits, two_bits);
+	}
+
+	if (cflag & PARENB) {
+		/* enable parity */
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, tr_par_en, enable);
+		info->rx_ctrl |= IO_STATE(R_SERIAL0_REC_CTRL, rec_par_en, enable);
+	}
+
+	if (cflag & CMSPAR) {
+		/* enable stick parity, PARODD mean Mark which matches ETRAX */
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, tr_stick_par, stick);
+		info->rx_ctrl |= IO_STATE(R_SERIAL0_REC_CTRL, rec_stick_par, stick);
+	}
+	if (cflag & PARODD) {
+		/* set odd parity (or Mark if CMSPAR) */
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, tr_par, odd);
+		info->rx_ctrl |= IO_STATE(R_SERIAL0_REC_CTRL, rec_par, odd);
+	}
+
+	if (cflag & CRTSCTS) {
+		/* enable automatic CTS handling */
+		DFLOW(DEBUG_LOG(info->line, "FLOW auto_cts enabled\n", 0));
+		info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, auto_cts, active);
+	}
+
+	/* make sure the tx and rx are enabled */
+
+	info->tx_ctrl |= IO_STATE(R_SERIAL0_TR_CTRL, tr_enable, enable);
+	info->rx_ctrl |= IO_STATE(R_SERIAL0_REC_CTRL, rec_enable, enable);
+
+	/* actually write the control regs to the hardware */
+
+	info->ioport[REG_TR_CTRL] = info->tx_ctrl;
+	info->ioport[REG_REC_CTRL] = info->rx_ctrl;
+	xoff = IO_FIELD(R_SERIAL0_XOFF, xoff_char, STOP_CHAR(info->port.tty));
+	xoff |= IO_STATE(R_SERIAL0_XOFF, tx_stop, enable);
+	if (info->port.tty->termios->c_iflag & IXON ) {
+		DFLOW(DEBUG_LOG(info->line, "FLOW XOFF enabled 0x%02X\n",
+				STOP_CHAR(info->port.tty)));
+		xoff |= IO_STATE(R_SERIAL0_XOFF, auto_xoff, enable);
+	}
+
+	*((unsigned long *)&info->ioport[REG_XOFF]) = xoff;
+	local_irq_restore(flags);
+#endif /* !CONFIG_SVINTO_SIM */
+
+	update_char_time(info);
+
+} /* change_speed */
+
+/* start transmitting chars NOW */
+
+static void
+rs_flush_chars(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	if (info->tr_running ||
+	    info->xmit.head == info->xmit.tail ||
+	    tty->stopped ||
+	    tty->hw_stopped ||
+	    !info->xmit.buf)
+		return;
+
+#ifdef SERIAL_DEBUG_FLOW
+	printk("rs_flush_chars\n");
+#endif
+
+	/* this protection might not exactly be necessary here */
+
+	local_irq_save(flags);
+	start_transmit(info);
+	local_irq_restore(flags);
+}
+
+static int rs_raw_write(struct tty_struct *tty,
+			const unsigned char *buf, int count)
+{
+	int	c, ret = 0;
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	/* first some sanity checks */
+
+	if (!tty || !info->xmit.buf || !tmp_buf)
+		return 0;
+
+#ifdef SERIAL_DEBUG_DATA
+	if (info->line == SERIAL_DEBUG_LINE)
+		printk("rs_raw_write (%d), status %d\n",
+		       count, info->ioport[REG_STATUS]);
+#endif
+
+#ifdef CONFIG_SVINTO_SIM
+	/* Really simple.  The output is here and now. */
+	SIMCOUT(buf, count);
+	return count;
+#endif
+	local_save_flags(flags);
+	DFLOW(DEBUG_LOG(info->line, "write count %i ", count));
+	DFLOW(DEBUG_LOG(info->line, "ldisc %i\n", tty->ldisc.chars_in_buffer(tty)));
+
+
+	/* The local_irq_disable/restore_flags pairs below are needed
+	 * because the DMA interrupt handler moves the info->xmit values.
+	 * the memcpy needs to be in the critical region unfortunately,
+	 * because we need to read xmit values, memcpy, write xmit values
+	 * in one atomic operation... this could perhaps be avoided by
+	 * more clever design.
+	 */
+	local_irq_disable();
+		while (count) {
+			c = CIRC_SPACE_TO_END(info->xmit.head,
+					      info->xmit.tail,
+					      SERIAL_XMIT_SIZE);
+
+			if (count < c)
+				c = count;
+			if (c <= 0)
+				break;
+
+			memcpy(info->xmit.buf + info->xmit.head, buf, c);
+			info->xmit.head = (info->xmit.head + c) &
+				(SERIAL_XMIT_SIZE-1);
+			buf += c;
+			count -= c;
+			ret += c;
+		}
+	local_irq_restore(flags);
+
+	/* enable transmitter if not running, unless the tty is stopped
+	 * this does not need IRQ protection since if tr_running == 0
+	 * the IRQ's are not running anyway for this port.
+	 */
+	DFLOW(DEBUG_LOG(info->line, "write ret %i\n", ret));
+
+	if (info->xmit.head != info->xmit.tail &&
+	    !tty->stopped &&
+	    !tty->hw_stopped &&
+	    !info->tr_running) {
+		start_transmit(info);
+	}
+
+	return ret;
+} /* raw_raw_write() */
+
+static int
+rs_write(struct tty_struct *tty,
+	 const unsigned char *buf, int count)
+{
+#if defined(CONFIG_ETRAX_RS485)
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+
+	if (info->rs485.flags & SER_RS485_ENABLED)
+	{
+		/* If we are in RS-485 mode, we need to toggle RTS and disable
+		 * the receiver before initiating a DMA transfer
+		 */
+#ifdef CONFIG_ETRAX_FAST_TIMER
+		/* Abort any started timer */
+		fast_timers_rs485[info->line].function = NULL;
+		del_fast_timer(&fast_timers_rs485[info->line]);
+#endif
+		e100_rts(info, (info->rs485.flags & SER_RS485_RTS_ON_SEND));
+#if defined(CONFIG_ETRAX_RS485_DISABLE_RECEIVER)
+		e100_disable_rx(info);
+		e100_enable_rx_irq(info);
+#endif
+		if ((info->rs485.flags & SER_RS485_RTS_BEFORE_SEND) &&
+			(info->rs485.delay_rts_before_send > 0))
+				msleep(info->rs485.delay_rts_before_send);
+	}
+#endif /* CONFIG_ETRAX_RS485 */
+
+	count = rs_raw_write(tty, buf, count);
+
+#if defined(CONFIG_ETRAX_RS485)
+	if (info->rs485.flags & SER_RS485_ENABLED)
+	{
+		unsigned int val;
+		/* If we are in RS-485 mode the following has to be done:
+		 * wait until DMA is ready
+		 * wait on transmit shift register
+		 * toggle RTS
+		 * enable the receiver
+		 */
+
+		/* Sleep until all sent */
+		tty_wait_until_sent(tty, 0);
+#ifdef CONFIG_ETRAX_FAST_TIMER
+		/* Now sleep a little more so that shift register is empty */
+		schedule_usleep(info->char_time_usec * 2);
+#endif
+		/* wait on transmit shift register */
+		do{
+			get_lsr_info(info, &val);
+		}while (!(val & TIOCSER_TEMT));
+
+		e100_rts(info, (info->rs485.flags & SER_RS485_RTS_AFTER_SEND));
+
+#if defined(CONFIG_ETRAX_RS485_DISABLE_RECEIVER)
+		e100_enable_rx(info);
+		e100_enable_rxdma_irq(info);
+#endif
+	}
+#endif /* CONFIG_ETRAX_RS485 */
+
+	return count;
+} /* rs_write */
+
+
+/* how much space is available in the xmit buffer? */
+
+static int
+rs_write_room(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+
+	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+/* How many chars are in the xmit buffer?
+ * This does not include any chars in the transmitter FIFO.
+ * Use wait_until_sent for waiting for FIFO drain.
+ */
+
+static int
+rs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+
+	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+/* discard everything in the xmit buffer */
+
+static void
+rs_flush_buffer(struct tty_struct *tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	info->xmit.head = info->xmit.tail = 0;
+	local_irq_restore(flags);
+
+	tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ *
+ * Since we use DMA we don't check for info->x_char in transmit_chars_dma(),
+ * but we do it in handle_ser_tx_interrupt().
+ * We disable DMA channel and enable tx ready interrupt and write the
+ * character when possible.
+ */
+static void rs_send_xchar(struct tty_struct *tty, char ch)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+	local_irq_save(flags);
+	if (info->uses_dma_out) {
+		/* Put the DMA on hold and disable the channel */
+		*info->ocmdadr = IO_STATE(R_DMA_CH6_CMD, cmd, hold);
+		while (IO_EXTRACT(R_DMA_CH6_CMD, cmd, *info->ocmdadr) !=
+		       IO_STATE_VALUE(R_DMA_CH6_CMD, cmd, hold));
+		e100_disable_txdma_channel(info);
+	}
+
+	/* Must make sure transmitter is not stopped before we can transmit */
+	if (tty->stopped)
+		rs_start(tty);
+
+	/* Enable manual transmit interrupt and send from there */
+	DFLOW(DEBUG_LOG(info->line, "rs_send_xchar 0x%02X\n", ch));
+	info->x_char = ch;
+	e100_enable_serial_tx_ready_irq(info);
+	local_irq_restore(flags);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_throttle()
+ *
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ * ------------------------------------------------------------
+ */
+static void
+rs_throttle(struct tty_struct * tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+
+	printk("throttle %s: %lu....\n", tty_name(tty, buf),
+	       (unsigned long)tty->ldisc.chars_in_buffer(tty));
+#endif
+	DFLOW(DEBUG_LOG(info->line,"rs_throttle %lu\n", tty->ldisc.chars_in_buffer(tty)));
+
+	/* Do RTS before XOFF since XOFF might take some time */
+	if (tty->termios->c_cflag & CRTSCTS) {
+		/* Turn off RTS line */
+		e100_rts(info, 0);
+	}
+	if (I_IXOFF(tty))
+		rs_send_xchar(tty, STOP_CHAR(tty));
+
+}
+
+static void
+rs_unthrottle(struct tty_struct * tty)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+
+	printk("unthrottle %s: %lu....\n", tty_name(tty, buf),
+	       (unsigned long)tty->ldisc.chars_in_buffer(tty));
+#endif
+	DFLOW(DEBUG_LOG(info->line,"rs_unthrottle ldisc %d\n", tty->ldisc.chars_in_buffer(tty)));
+	DFLOW(DEBUG_LOG(info->line,"rs_unthrottle flip.count: %i\n", tty->flip.count));
+	/* Do RTS before XOFF since XOFF might take some time */
+	if (tty->termios->c_cflag & CRTSCTS) {
+		/* Assert RTS line  */
+		e100_rts(info, 1);
+	}
+
+	if (I_IXOFF(tty)) {
+		if (info->x_char)
+			info->x_char = 0;
+		else
+			rs_send_xchar(tty, START_CHAR(tty));
+	}
+
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_ioctl() and friends
+ * ------------------------------------------------------------
+ */
+
+static int
+get_serial_info(struct e100_serial * info,
+		struct serial_struct * retinfo)
+{
+	struct serial_struct tmp;
+
+	/* this is all probably wrong, there are a lot of fields
+	 * here that we don't have in e100_serial and maybe we
+	 * should set them to something else than 0.
+	 */
+
+	if (!retinfo)
+		return -EFAULT;
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.type = info->type;
+	tmp.line = info->line;
+	tmp.port = (int)info->ioport;
+	tmp.irq = info->irq;
+	tmp.flags = info->flags;
+	tmp.baud_base = info->baud_base;
+	tmp.close_delay = info->close_delay;
+	tmp.closing_wait = info->closing_wait;
+	tmp.custom_divisor = info->custom_divisor;
+	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
+		return -EFAULT;
+	return 0;
+}
+
+static int
+set_serial_info(struct e100_serial *info,
+		struct serial_struct *new_info)
+{
+	struct serial_struct new_serial;
+	struct e100_serial old_info;
+	int retval = 0;
+
+	if (copy_from_user(&new_serial, new_info, sizeof(new_serial)))
+		return -EFAULT;
+
+	old_info = *info;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		if ((new_serial.type != info->type) ||
+		    (new_serial.close_delay != info->close_delay) ||
+		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
+		     (info->flags & ~ASYNC_USR_MASK)))
+			return -EPERM;
+		info->flags = ((info->flags & ~ASYNC_USR_MASK) |
+			       (new_serial.flags & ASYNC_USR_MASK));
+		goto check_and_exit;
+	}
+
+	if (info->count > 1)
+		return -EBUSY;
+
+	/*
+	 * OK, past this point, all the error checking has been done.
+	 * At this point, we start making changes.....
+	 */
+
+	info->baud_base = new_serial.baud_base;
+	info->flags = ((info->flags & ~ASYNC_FLAGS) |
+		       (new_serial.flags & ASYNC_FLAGS));
+	info->custom_divisor = new_serial.custom_divisor;
+	info->type = new_serial.type;
+	info->close_delay = new_serial.close_delay;
+	info->closing_wait = new_serial.closing_wait;
+	info->port.tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+ check_and_exit:
+	if (info->flags & ASYNC_INITIALIZED) {
+		change_speed(info);
+	} else
+		retval = startup(info);
+	return retval;
+}
+
+/*
+ * get_lsr_info - get line status register info
+ *
+ * Purpose: Let user call ioctl() to get info when the UART physically
+ * 	    is emptied.  On bus types like RS485, the transmitter must
+ * 	    release the bus after transmitting. This must be done when
+ * 	    the transmit shift register is empty, not be done when the
+ * 	    transmit holding register is empty.  This functionality
+ * 	    allows an RS485 driver to be written in user space.
+ */
+static int
+get_lsr_info(struct e100_serial * info, unsigned int *value)
+{
+	unsigned int result = TIOCSER_TEMT;
+#ifndef CONFIG_SVINTO_SIM
+	unsigned long curr_time = jiffies;
+	unsigned long curr_time_usec = GET_JIFFIES_USEC();
+	unsigned long elapsed_usec =
+		(curr_time - info->last_tx_active) * 1000000/HZ +
+		curr_time_usec - info->last_tx_active_usec;
+
+	if (info->xmit.head != info->xmit.tail ||
+	    elapsed_usec < 2*info->char_time_usec) {
+		result = 0;
+	}
+#endif
+
+	if (copy_to_user(value, &result, sizeof(int)))
+		return -EFAULT;
+	return 0;
+}
+
+#ifdef SERIAL_DEBUG_IO
+struct state_str
+{
+	int state;
+	const char *str;
+};
+
+const struct state_str control_state_str[] = {
+	{TIOCM_DTR, "DTR" },
+	{TIOCM_RTS, "RTS"},
+	{TIOCM_ST, "ST?" },
+	{TIOCM_SR, "SR?" },
+	{TIOCM_CTS, "CTS" },
+	{TIOCM_CD, "CD" },
+	{TIOCM_RI, "RI" },
+	{TIOCM_DSR, "DSR" },
+	{0, NULL }
+};
+
+char *get_control_state_str(int MLines, char *s)
+{
+	int i = 0;
+
+	s[0]='\0';
+	while (control_state_str[i].str != NULL) {
+		if (MLines & control_state_str[i].state) {
+			if (s[0] != '\0') {
+				strcat(s, ", ");
+			}
+			strcat(s, control_state_str[i].str);
+		}
+		i++;
+	}
+	return s;
+}
+#endif
+
+static int
+rs_break(struct tty_struct *tty, int break_state)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	if (!info->ioport)
+		return -EIO;
+
+	local_irq_save(flags);
+	if (break_state == -1) {
+		/* Go to manual mode and set the txd pin to 0 */
+		/* Clear bit 7 (txd) and 6 (tr_enable) */
+		info->tx_ctrl &= 0x3F;
+	} else {
+		/* Set bit 7 (txd) and 6 (tr_enable) */
+		info->tx_ctrl |= (0x80 | 0x40);
+	}
+	info->ioport[REG_TR_CTRL] = info->tx_ctrl;
+	local_irq_restore(flags);
+	return 0;
+}
+
+static int
+rs_tiocmset(struct tty_struct *tty, struct file *file,
+		unsigned int set, unsigned int clear)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	if (clear & TIOCM_RTS)
+		e100_rts(info, 0);
+	if (clear & TIOCM_DTR)
+		e100_dtr(info, 0);
+	/* Handle FEMALE behaviour */
+	if (clear & TIOCM_RI)
+		e100_ri_out(info, 0);
+	if (clear & TIOCM_CD)
+		e100_cd_out(info, 0);
+
+	if (set & TIOCM_RTS)
+		e100_rts(info, 1);
+	if (set & TIOCM_DTR)
+		e100_dtr(info, 1);
+	/* Handle FEMALE behaviour */
+	if (set & TIOCM_RI)
+		e100_ri_out(info, 1);
+	if (set & TIOCM_CD)
+		e100_cd_out(info, 1);
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+static int
+rs_tiocmget(struct tty_struct *tty, struct file *file)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned int result;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	result =
+		(!E100_RTS_GET(info) ? TIOCM_RTS : 0)
+		| (!E100_DTR_GET(info) ? TIOCM_DTR : 0)
+		| (!E100_RI_GET(info) ? TIOCM_RNG : 0)
+		| (!E100_DSR_GET(info) ? TIOCM_DSR : 0)
+		| (!E100_CD_GET(info) ? TIOCM_CAR : 0)
+		| (!E100_CTS_GET(info) ? TIOCM_CTS : 0);
+
+	local_irq_restore(flags);
+
+#ifdef SERIAL_DEBUG_IO
+	printk(KERN_DEBUG "ser%i: modem state: %i 0x%08X\n",
+		info->line, result, result);
+	{
+		char s[100];
+
+		get_control_state_str(result, s);
+		printk(KERN_DEBUG "state: %s\n", s);
+	}
+#endif
+	return result;
+
+}
+
+
+static int
+rs_ioctl(struct tty_struct *tty, struct file * file,
+	 unsigned int cmd, unsigned long arg)
+{
+	struct e100_serial * info = (struct e100_serial *)tty->driver_data;
+
+	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
+	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
+		if (tty->flags & (1 << TTY_IO_ERROR))
+			return -EIO;
+	}
+
+	switch (cmd) {
+	case TIOCGSERIAL:
+		return get_serial_info(info,
+				       (struct serial_struct *) arg);
+	case TIOCSSERIAL:
+		return set_serial_info(info,
+				       (struct serial_struct *) arg);
+	case TIOCSERGETLSR: /* Get line status register */
+		return get_lsr_info(info, (unsigned int *) arg);
+
+	case TIOCSERGSTRUCT:
+		if (copy_to_user((struct e100_serial *) arg,
+				 info, sizeof(struct e100_serial)))
+			return -EFAULT;
+		return 0;
+
+#if defined(CONFIG_ETRAX_RS485)
+	case TIOCSERSETRS485:
+	{
+		/* In this ioctl we still use the old structure
+		 * rs485_control for backward compatibility
+		 * (if we use serial_rs485, then old user-level code
+		 * wouldn't work anymore...).
+		 * The use of this ioctl is deprecated: use TIOCSRS485
+		 * instead.*/
+		struct rs485_control rs485ctrl;
+		struct serial_rs485 rs485data;
+		printk(KERN_DEBUG "The use of this ioctl is deprecated. Use TIOCSRS485 instead\n");
+		if (copy_from_user(&rs485ctrl, (struct rs485_control *)arg,
+				sizeof(rs485ctrl)))
+			return -EFAULT;
+
+		rs485data.delay_rts_before_send = rs485ctrl.delay_rts_before_send;
+		rs485data.flags = 0;
+		if (rs485data.delay_rts_before_send != 0)
+			rs485data.flags |= SER_RS485_RTS_BEFORE_SEND;
+		else
+			rs485data.flags &= ~(SER_RS485_RTS_BEFORE_SEND);
+
+		if (rs485ctrl.enabled)
+			rs485data.flags |= SER_RS485_ENABLED;
+		else
+			rs485data.flags &= ~(SER_RS485_ENABLED);
+
+		if (rs485ctrl.rts_on_send)
+			rs485data.flags |= SER_RS485_RTS_ON_SEND;
+		else
+			rs485data.flags &= ~(SER_RS485_RTS_ON_SEND);
+
+		if (rs485ctrl.rts_after_sent)
+			rs485data.flags |= SER_RS485_RTS_AFTER_SEND;
+		else
+			rs485data.flags &= ~(SER_RS485_RTS_AFTER_SEND);
+
+		return e100_enable_rs485(tty, &rs485data);
+	}
+
+	case TIOCSRS485:
+	{
+		/* This is the new version of TIOCSRS485, with new
+		 * data structure serial_rs485 */
+		struct serial_rs485 rs485data;
+		if (copy_from_user(&rs485data, (struct rs485_control *)arg,
+				sizeof(rs485data)))
+			return -EFAULT;
+
+		return e100_enable_rs485(tty, &rs485data);
+	}
+
+	case TIOCGRS485:
+	{
+		struct serial_rs485 *rs485data =
+			&(((struct e100_serial *)tty->driver_data)->rs485);
+		/* This is the ioctl to get RS485 data from user-space */
+		if (copy_to_user((struct serial_rs485 *) arg,
+					rs485data,
+					sizeof(struct serial_rs485)))
+			return -EFAULT;
+		break;
+	}
+
+	case TIOCSERWRRS485:
+	{
+		struct rs485_write rs485wr;
+		if (copy_from_user(&rs485wr, (struct rs485_write *)arg,
+				sizeof(rs485wr)))
+			return -EFAULT;
+
+		return e100_write_rs485(tty, rs485wr.outc, rs485wr.outc_size);
+	}
+#endif
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+static void
+rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+{
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+
+	change_speed(info);
+
+	/* Handle turning off CRTSCTS */
+	if ((old_termios->c_cflag & CRTSCTS) &&
+	    !(tty->termios->c_cflag & CRTSCTS)) {
+		tty->hw_stopped = 0;
+		rs_start(tty);
+	}
+
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_close()
+ *
+ * This routine is called when the serial port gets closed.  First, we
+ * wait for the last remaining data to be sent.  Then, we unlink its
+ * S structure from the interrupt chain if necessary, and we free
+ * that IRQ if nothing is left in the chain.
+ * ------------------------------------------------------------
+ */
+static void
+rs_close(struct tty_struct *tty, struct file * filp)
+{
+	struct e100_serial * info = (struct e100_serial *)tty->driver_data;
+	unsigned long flags;
+
+	if (!info)
+		return;
+
+	/* interrupts are disabled for this entire function */
+
+	local_irq_save(flags);
+
+	if (tty_hung_up_p(filp)) {
+		local_irq_restore(flags);
+		return;
+	}
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("[%d] rs_close ttyS%d, count = %d\n", current->pid,
+	       info->line, info->count);
+#endif
+	if ((tty->count == 1) && (info->count != 1)) {
+		/*
+		 * Uh, oh.  tty->count is 1, which means that the tty
+		 * structure will be freed.  Info->count should always
+		 * be one in these conditions.  If it's greater than
+		 * one, we've got real problems, since it means the
+		 * serial port won't be shutdown.
+		 */
+		printk(KERN_CRIT
+		       "rs_close: bad serial port count; tty->count is 1, "
+		       "info->count is %d\n", info->count);
+		info->count = 1;
+	}
+	if (--info->count < 0) {
+		printk(KERN_CRIT "rs_close: bad serial port count for ttyS%d: %d\n",
+		       info->line, info->count);
+		info->count = 0;
+	}
+	if (info->count) {
+		local_irq_restore(flags);
+		return;
+	}
+	info->flags |= ASYNC_CLOSING;
+	/*
+	 * Save the termios structure, since this port may have
+	 * separate termios for callout and dialin.
+	 */
+	if (info->flags & ASYNC_NORMAL_ACTIVE)
+		info->normal_termios = *tty->termios;
+	/*
+	 * Now we wait for the transmit buffer to clear; and we notify
+	 * the line discipline to only process XON/XOFF characters.
+	 */
+	tty->closing = 1;
+	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		tty_wait_until_sent(tty, info->closing_wait);
+	/*
+	 * At this point we stop accepting input.  To do this, we
+	 * disable the serial receiver and the DMA receive interrupt.
+	 */
+#ifdef SERIAL_HANDLE_EARLY_ERRORS
+	e100_disable_serial_data_irq(info);
+#endif
+
+#ifndef CONFIG_SVINTO_SIM
+	e100_disable_rx(info);
+	e100_disable_rx_irq(info);
+
+	if (info->flags & ASYNC_INITIALIZED) {
+		/*
+		 * Before we drop DTR, make sure the UART transmitter
+		 * has completely drained; this is especially
+		 * important as we have a transmit FIFO!
+		 */
+		rs_wait_until_sent(tty, HZ);
+	}
+#endif
+
+	shutdown(info);
+	rs_flush_buffer(tty);
+	tty_ldisc_flush(tty);
+	tty->closing = 0;
+	info->event = 0;
+	info->port.tty = NULL;
+	if (info->blocked_open) {
+		if (info->close_delay)
+			schedule_timeout_interruptible(info->close_delay);
+		wake_up_interruptible(&info->open_wait);
+	}
+	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
+	wake_up_interruptible(&info->close_wait);
+	local_irq_restore(flags);
+
+	/* port closed */
+
+#if defined(CONFIG_ETRAX_RS485)
+	if (info->rs485.flags & SER_RS485_ENABLED) {
+		info->rs485.flags &= ~(SER_RS485_ENABLED);
+#if defined(CONFIG_ETRAX_RS485_ON_PA)
+		*R_PORT_PA_DATA = port_pa_data_shadow &= ~(1 << rs485_pa_bit);
+#endif
+#if defined(CONFIG_ETRAX_RS485_ON_PORT_G)
+		REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow,
+			       rs485_port_g_bit, 0);
+#endif
+#if defined(CONFIG_ETRAX_RS485_LTC1387)
+		REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow,
+			       CONFIG_ETRAX_RS485_LTC1387_DXEN_PORT_G_BIT, 0);
+		REG_SHADOW_SET(R_PORT_G_DATA, port_g_data_shadow,
+			       CONFIG_ETRAX_RS485_LTC1387_RXEN_PORT_G_BIT, 0);
+#endif
+	}
+#endif
+
+	/*
+	 * Release any allocated DMA irq's.
+	 */
+	if (info->dma_in_enabled) {
+		free_irq(info->dma_in_irq_nbr, info);
+		cris_free_dma(info->dma_in_nbr, info->dma_in_irq_description);
+		info->uses_dma_in = 0;
+#ifdef SERIAL_DEBUG_OPEN
+		printk(KERN_DEBUG "DMA irq '%s' freed\n",
+			info->dma_in_irq_description);
+#endif
+	}
+	if (info->dma_out_enabled) {
+		free_irq(info->dma_out_irq_nbr, info);
+		cris_free_dma(info->dma_out_nbr, info->dma_out_irq_description);
+		info->uses_dma_out = 0;
+#ifdef SERIAL_DEBUG_OPEN
+		printk(KERN_DEBUG "DMA irq '%s' freed\n",
+			info->dma_out_irq_description);
+#endif
+	}
+}
+
+/*
+ * rs_wait_until_sent() --- wait until the transmitter is empty
+ */
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	unsigned long orig_jiffies;
+	struct e100_serial *info = (struct e100_serial *)tty->driver_data;
+	unsigned long curr_time = jiffies;
+	unsigned long curr_time_usec = GET_JIFFIES_USEC();
+	long elapsed_usec =
+		(curr_time - info->last_tx_active) * (1000000/HZ) +
+		curr_time_usec - info->last_tx_active_usec;
+
+	/*
+	 * Check R_DMA_CHx_STATUS bit 0-6=number of available bytes in FIFO
+	 * R_DMA_CHx_HWSW bit 31-16=nbr of bytes left in DMA buffer (0=64k)
+	 */
+	orig_jiffies = jiffies;
+	while (info->xmit.head != info->xmit.tail || /* More in send queue */
+	       (*info->ostatusadr & 0x007f) ||  /* more in FIFO */
+	       (elapsed_usec < 2*info->char_time_usec)) {
+		schedule_timeout_interruptible(1);
+		if (signal_pending(current))
+			break;
+		if (timeout && time_after(jiffies, orig_jiffies + timeout))
+			break;
+		curr_time = jiffies;
+		curr_time_usec = GET_JIFFIES_USEC();
+		elapsed_usec =
+			(curr_time - info->last_tx_active) * (1000000/HZ) +
+			curr_time_usec - info->last_tx_active_usec;
+	}
+	set_current_state(TASK_RUNNING);
+}
+
+/*
+ * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
+ */
+void
+rs_hangup(struct tty_struct *tty)
+{
+	struct e100_serial * info = (struct e100_serial *)tty->driver_data;
+
+	rs_flush_buffer(tty);
+	shutdown(info);
+	info->event = 0;
+	info->count = 0;
+	info->flags &= ~ASYNC_NORMAL_ACTIVE;
+	info->port.tty = NULL;
+	wake_up_interruptible(&info->open_wait);
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_open() and friends
+ * ------------------------------------------------------------
+ */
+static int
+block_til_ready(struct tty_struct *tty, struct file * filp,
+		struct e100_serial *info)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	unsigned long	flags;
+	int		retval;
+	int		do_clocal = 0, extra_count = 0;
+
+	/*
+	 * If the device is in the middle of being closed, then block
+	 * until it's done, and then try again.
+	 */
+	if (tty_hung_up_p(filp) ||
+	    (info->flags & ASYNC_CLOSING)) {
+		wait_event_interruptible_tty(info->close_wait,
+			!(info->flags & ASYNC_CLOSING));
+#ifdef SERIAL_DO_RESTART
+		if (info->flags & ASYNC_HUP_NOTIFY)
+			return -EAGAIN;
+		else
+			return -ERESTARTSYS;
+#else
+		return -EAGAIN;
+#endif
+	}
+
+	/*
+	 * If non-blocking mode is set, or the port is not enabled,
+	 * then make the check up front and then exit.
+	 */
+	if ((filp->f_flags & O_NONBLOCK) ||
+	    (tty->flags & (1 << TTY_IO_ERROR))) {
+		info->flags |= ASYNC_NORMAL_ACTIVE;
+		return 0;
+	}
+
+	if (tty->termios->c_cflag & CLOCAL) {
+			do_clocal = 1;
+	}
+
+	/*
+	 * Block waiting for the 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
+	 * rs_close() knows when to free things.  We restore it upon
+	 * exit, either normal or abnormal.
+	 */
+	retval = 0;
+	add_wait_queue(&info->open_wait, &wait);
+#ifdef SERIAL_DEBUG_OPEN
+	printk("block_til_ready before block: ttyS%d, count = %d\n",
+	       info->line, info->count);
+#endif
+	local_irq_save(flags);
+	if (!tty_hung_up_p(filp)) {
+		extra_count++;
+		info->count--;
+	}
+	local_irq_restore(flags);
+	info->blocked_open++;
+	while (1) {
+		local_irq_save(flags);
+		/* assert RTS and DTR */
+		e100_rts(info, 1);
+		e100_dtr(info, 1);
+		local_irq_restore(flags);
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (tty_hung_up_p(filp) ||
+		    !(info->flags & ASYNC_INITIALIZED)) {
+#ifdef SERIAL_DO_RESTART
+			if (info->flags & ASYNC_HUP_NOTIFY)
+				retval = -EAGAIN;
+			else
+				retval = -ERESTARTSYS;
+#else
+			retval = -EAGAIN;
+#endif
+			break;
+		}
+		if (!(info->flags & ASYNC_CLOSING) && do_clocal)
+			/* && (do_clocal || DCD_IS_ASSERTED) */
+			break;
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+#ifdef SERIAL_DEBUG_OPEN
+		printk("block_til_ready blocking: ttyS%d, count = %d\n",
+		       info->line, info->count);
+#endif
+		tty_unlock();
+		schedule();
+		tty_lock();
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&info->open_wait, &wait);
+	if (extra_count)
+		info->count++;
+	info->blocked_open--;
+#ifdef SERIAL_DEBUG_OPEN
+	printk("block_til_ready after blocking: ttyS%d, count = %d\n",
+	       info->line, info->count);
+#endif
+	if (retval)
+		return retval;
+	info->flags |= ASYNC_NORMAL_ACTIVE;
+	return 0;
+}
+
+static void
+deinit_port(struct e100_serial *info)
+{
+	if (info->dma_out_enabled) {
+		cris_free_dma(info->dma_out_nbr, info->dma_out_irq_description);
+		free_irq(info->dma_out_irq_nbr, info);
+	}
+	if (info->dma_in_enabled) {
+		cris_free_dma(info->dma_in_nbr, info->dma_in_irq_description);
+		free_irq(info->dma_in_irq_nbr, info);
+	}
+}
+
+/*
+ * This routine is called whenever a serial port is opened.
+ * It performs the serial-specific initialization for the tty structure.
+ */
+static int
+rs_open(struct tty_struct *tty, struct file * filp)
+{
+	struct e100_serial	*info;
+	int 			retval, line;
+	unsigned long           page;
+	int                     allocated_resources = 0;
+
+	/* find which port we want to open */
+	line = tty->index;
+
+	if (line < 0 || line >= NR_PORTS)
+		return -ENODEV;
+
+	/* find the corresponding e100_serial struct in the table */
+	info = rs_table + line;
+
+	/* don't allow the opening of ports that are not enabled in the HW config */
+	if (!info->enabled)
+		return -ENODEV;
+
+#ifdef SERIAL_DEBUG_OPEN
+        printk("[%d] rs_open %s, count = %d\n", current->pid, tty->name,
+ 	       info->count);
+#endif
+
+	info->count++;
+	tty->driver_data = info;
+	info->port.tty = tty;
+
+	info->port.tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+	if (!tmp_buf) {
+		page = get_zeroed_page(GFP_KERNEL);
+		if (!page) {
+			return -ENOMEM;
+		}
+		if (tmp_buf)
+			free_page(page);
+		else
+			tmp_buf = (unsigned char *) page;
+	}
+
+	/*
+	 * If the port is in the middle of closing, bail out now
+	 */
+	if (tty_hung_up_p(filp) ||
+	    (info->flags & ASYNC_CLOSING)) {
+		wait_event_interruptible_tty(info->close_wait,
+			!(info->flags & ASYNC_CLOSING));
+#ifdef SERIAL_DO_RESTART
+		return ((info->flags & ASYNC_HUP_NOTIFY) ?
+			-EAGAIN : -ERESTARTSYS);
+#else
+		return -EAGAIN;
+#endif
+	}
+
+	/*
+	 * If DMA is enabled try to allocate the irq's.
+	 */
+	if (info->count == 1) {
+		allocated_resources = 1;
+		if (info->dma_in_enabled) {
+			if (request_irq(info->dma_in_irq_nbr,
+					rec_interrupt,
+					info->dma_in_irq_flags,
+					info->dma_in_irq_description,
+					info)) {
+				printk(KERN_WARNING "DMA irq '%s' busy; "
+					"falling back to non-DMA mode\n",
+					info->dma_in_irq_description);
+				/* Make sure we never try to use DMA in */
+				/* for the port again. */
+				info->dma_in_enabled = 0;
+			} else if (cris_request_dma(info->dma_in_nbr,
+					info->dma_in_irq_description,
+					DMA_VERBOSE_ON_ERROR,
+					info->dma_owner)) {
+				free_irq(info->dma_in_irq_nbr, info);
+				printk(KERN_WARNING "DMA '%s' busy; "
+					"falling back to non-DMA mode\n",
+					info->dma_in_irq_description);
+				/* Make sure we never try to use DMA in */
+				/* for the port again. */
+				info->dma_in_enabled = 0;
+			}
+#ifdef SERIAL_DEBUG_OPEN
+			else
+				printk(KERN_DEBUG "DMA irq '%s' allocated\n",
+					info->dma_in_irq_description);
+#endif
+		}
+		if (info->dma_out_enabled) {
+			if (request_irq(info->dma_out_irq_nbr,
+					       tr_interrupt,
+					       info->dma_out_irq_flags,
+					       info->dma_out_irq_description,
+					       info)) {
+				printk(KERN_WARNING "DMA irq '%s' busy; "
+					"falling back to non-DMA mode\n",
+					info->dma_out_irq_description);
+				/* Make sure we never try to use DMA out */
+				/* for the port again. */
+				info->dma_out_enabled = 0;
+			} else if (cris_request_dma(info->dma_out_nbr,
+					     info->dma_out_irq_description,
+					     DMA_VERBOSE_ON_ERROR,
+					     info->dma_owner)) {
+				free_irq(info->dma_out_irq_nbr, info);
+				printk(KERN_WARNING "DMA '%s' busy; "
+					"falling back to non-DMA mode\n",
+					info->dma_out_irq_description);
+				/* Make sure we never try to use DMA out */
+				/* for the port again. */
+				info->dma_out_enabled = 0;
+			}
+#ifdef SERIAL_DEBUG_OPEN
+			else
+				printk(KERN_DEBUG "DMA irq '%s' allocated\n",
+					info->dma_out_irq_description);
+#endif
+		}
+	}
+
+	/*
+	 * Start up the serial port
+	 */
+
+	retval = startup(info);
+	if (retval) {
+		if (allocated_resources)
+			deinit_port(info);
+
+		/* FIXME Decrease count info->count here too? */
+		return retval;
+	}
+
+
+	retval = block_til_ready(tty, filp, info);
+	if (retval) {
+#ifdef SERIAL_DEBUG_OPEN
+		printk("rs_open returning after block_til_ready with %d\n",
+		       retval);
+#endif
+		if (allocated_resources)
+			deinit_port(info);
+
+		return retval;
+	}
+
+	if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) {
+		*tty->termios = info->normal_termios;
+		change_speed(info);
+	}
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("rs_open ttyS%d successful...\n", info->line);
+#endif
+	DLOG_INT_TRIG( log_int_pos = 0);
+
+	DFLIP(	if (info->line == SERIAL_DEBUG_LINE) {
+			info->icount.rx = 0;
+		} );
+
+	return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+/*
+ * /proc fs routines....
+ */
+
+static void seq_line_info(struct seq_file *m, struct e100_serial *info)
+{
+	unsigned long tmp;
+
+	seq_printf(m, "%d: uart:E100 port:%lX irq:%d",
+		   info->line, (unsigned long)info->ioport, info->irq);
+
+	if (!info->ioport || (info->type == PORT_UNKNOWN)) {
+		seq_printf(m, "\n");
+		return;
+	}
+
+	seq_printf(m, " baud:%d", info->baud);
+	seq_printf(m, " tx:%lu rx:%lu",
+		       (unsigned long)info->icount.tx,
+		       (unsigned long)info->icount.rx);
+	tmp = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+	if (tmp)
+		seq_printf(m, " tx_pend:%lu/%lu",
+			   (unsigned long)tmp,
+			   (unsigned long)SERIAL_XMIT_SIZE);
+
+	seq_printf(m, " rx_pend:%lu/%lu",
+		   (unsigned long)info->recv_cnt,
+		   (unsigned long)info->max_recv_cnt);
+
+#if 1
+	if (info->port.tty) {
+		if (info->port.tty->stopped)
+			seq_printf(m, " stopped:%i",
+				   (int)info->port.tty->stopped);
+		if (info->port.tty->hw_stopped)
+			seq_printf(m, " hw_stopped:%i",
+				   (int)info->port.tty->hw_stopped);
+	}
+
+	{
+		unsigned char rstat = info->ioport[REG_STATUS];
+		if (rstat & IO_MASK(R_SERIAL0_STATUS, xoff_detect))
+			seq_printf(m, " xoff_detect:1");
+	}
+
+#endif
+
+	if (info->icount.frame)
+		seq_printf(m, " fe:%lu", (unsigned long)info->icount.frame);
+
+	if (info->icount.parity)
+		seq_printf(m, " pe:%lu", (unsigned long)info->icount.parity);
+
+	if (info->icount.brk)
+		seq_printf(m, " brk:%lu", (unsigned long)info->icount.brk);
+
+	if (info->icount.overrun)
+		seq_printf(m, " oe:%lu", (unsigned long)info->icount.overrun);
+
+	/*
+	 * Last thing is the RS-232 status lines
+	 */
+	if (!E100_RTS_GET(info))
+		seq_puts(m, "|RTS");
+	if (!E100_CTS_GET(info))
+		seq_puts(m, "|CTS");
+	if (!E100_DTR_GET(info))
+		seq_puts(m, "|DTR");
+	if (!E100_DSR_GET(info))
+		seq_puts(m, "|DSR");
+	if (!E100_CD_GET(info))
+		seq_puts(m, "|CD");
+	if (!E100_RI_GET(info))
+		seq_puts(m, "|RI");
+	seq_puts(m, "\n");
+}
+
+
+static int crisv10_proc_show(struct seq_file *m, void *v)
+{
+	int i;
+
+	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
+
+	for (i = 0; i < NR_PORTS; i++) {
+		if (!rs_table[i].enabled)
+			continue;
+		seq_line_info(m, &rs_table[i]);
+	}
+#ifdef DEBUG_LOG_INCLUDED
+	for (i = 0; i < debug_log_pos; i++) {
+		seq_printf(m, "%-4i %lu.%lu ",
+			 i, debug_log[i].time,
+			 timer_data_to_ns(debug_log[i].timer_data));
+		seq_printf(m, debug_log[i].string, debug_log[i].value);
+	}
+	seq_printf(m, "debug_log %i/%i\n", i, DEBUG_LOG_SIZE);
+	debug_log_pos = 0;
+#endif
+	return 0;
+}
+
+static int crisv10_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, crisv10_proc_show, NULL);
+}
+
+static const struct file_operations crisv10_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= crisv10_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif
+
+
+/* Finally, routines used to initialize the serial driver. */
+
+static void show_serial_version(void)
+{
+	printk(KERN_INFO
+	       "ETRAX 100LX serial-driver %s, "
+	       "(c) 2000-2004 Axis Communications AB\r\n",
+	       &serial_version[11]); /* "$Revision: x.yy" */
+}
+
+/* rs_init inits the driver at boot (using the module_init chain) */
+
+static const struct tty_operations rs_ops = {
+	.open = rs_open,
+	.close = rs_close,
+	.write = rs_write,
+	.flush_chars = rs_flush_chars,
+	.write_room = rs_write_room,
+	.chars_in_buffer = rs_chars_in_buffer,
+	.flush_buffer = rs_flush_buffer,
+	.ioctl = rs_ioctl,
+	.throttle = rs_throttle,
+        .unthrottle = rs_unthrottle,
+	.set_termios = rs_set_termios,
+	.stop = rs_stop,
+	.start = rs_start,
+	.hangup = rs_hangup,
+	.break_ctl = rs_break,
+	.send_xchar = rs_send_xchar,
+	.wait_until_sent = rs_wait_until_sent,
+	.tiocmget = rs_tiocmget,
+	.tiocmset = rs_tiocmset,
+#ifdef CONFIG_PROC_FS
+	.proc_fops = &crisv10_proc_fops,
+#endif
+};
+
+static int __init rs_init(void)
+{
+	int i;
+	struct e100_serial *info;
+	struct tty_driver *driver = alloc_tty_driver(NR_PORTS);
+
+	if (!driver)
+		return -ENOMEM;
+
+	show_serial_version();
+
+	/* Setup the timed flush handler system */
+
+#if !defined(CONFIG_ETRAX_SERIAL_FAST_TIMER)
+	setup_timer(&flush_timer, timed_flush_handler, 0);
+	mod_timer(&flush_timer, jiffies + 5);
+#endif
+
+#if defined(CONFIG_ETRAX_RS485)
+#if defined(CONFIG_ETRAX_RS485_ON_PA)
+	if (cris_io_interface_allocate_pins(if_ser0, 'a', rs485_pa_bit,
+			rs485_pa_bit)) {
+		printk(KERN_CRIT "ETRAX100LX serial: Could not allocate "
+			"RS485 pin\n");
+		put_tty_driver(driver);
+		return -EBUSY;
+	}
+#endif
+#if defined(CONFIG_ETRAX_RS485_ON_PORT_G)
+	if (cris_io_interface_allocate_pins(if_ser0, 'g', rs485_pa_bit,
+			rs485_port_g_bit)) {
+		printk(KERN_CRIT "ETRAX100LX serial: Could not allocate "
+			"RS485 pin\n");
+		put_tty_driver(driver);
+		return -EBUSY;
+	}
+#endif
+#endif
+
+	/* Initialize the tty_driver structure */
+
+	driver->driver_name = "serial";
+	driver->name = "ttyS";
+	driver->major = TTY_MAJOR;
+	driver->minor_start = 64;
+	driver->type = TTY_DRIVER_TYPE_SERIAL;
+	driver->subtype = SERIAL_TYPE_NORMAL;
+	driver->init_termios = tty_std_termios;
+	driver->init_termios.c_cflag =
+		B115200 | CS8 | CREAD | HUPCL | CLOCAL; /* is normally B9600 default... */
+	driver->init_termios.c_ispeed = 115200;
+	driver->init_termios.c_ospeed = 115200;
+	driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+
+	tty_set_operations(driver, &rs_ops);
+        serial_driver = driver;
+	if (tty_register_driver(driver))
+		panic("Couldn't register serial driver\n");
+	/* do some initializing for the separate ports */
+
+	for (i = 0, info = rs_table; i < NR_PORTS; i++,info++) {
+		if (info->enabled) {
+			if (cris_request_io_interface(info->io_if,
+					info->io_if_description)) {
+				printk(KERN_CRIT "ETRAX100LX async serial: "
+					"Could not allocate IO pins for "
+					"%s, port %d\n",
+					info->io_if_description, i);
+				info->enabled = 0;
+			}
+		}
+		info->uses_dma_in = 0;
+		info->uses_dma_out = 0;
+		info->line = i;
+		info->port.tty = NULL;
+		info->type = PORT_ETRAX;
+		info->tr_running = 0;
+		info->forced_eop = 0;
+		info->baud_base = DEF_BAUD_BASE;
+		info->custom_divisor = 0;
+		info->flags = 0;
+		info->close_delay = 5*HZ/10;
+		info->closing_wait = 30*HZ;
+		info->x_char = 0;
+		info->event = 0;
+		info->count = 0;
+		info->blocked_open = 0;
+		info->normal_termios = driver->init_termios;
+		init_waitqueue_head(&info->open_wait);
+		init_waitqueue_head(&info->close_wait);
+		info->xmit.buf = NULL;
+		info->xmit.tail = info->xmit.head = 0;
+		info->first_recv_buffer = info->last_recv_buffer = NULL;
+		info->recv_cnt = info->max_recv_cnt = 0;
+		info->last_tx_active_usec = 0;
+		info->last_tx_active = 0;
+
+#if defined(CONFIG_ETRAX_RS485)
+		/* Set sane defaults */
+		info->rs485.flags &= ~(SER_RS485_RTS_ON_SEND);
+		info->rs485.flags |= SER_RS485_RTS_AFTER_SEND;
+		info->rs485.flags &= ~(SER_RS485_RTS_BEFORE_SEND);
+		info->rs485.delay_rts_before_send = 0;
+		info->rs485.flags &= ~(SER_RS485_ENABLED);
+#endif
+		INIT_WORK(&info->work, do_softint);
+
+		if (info->enabled) {
+			printk(KERN_INFO "%s%d at %p is a builtin UART with DMA\n",
+			       serial_driver->name, info->line, info->ioport);
+		}
+	}
+#ifdef CONFIG_ETRAX_FAST_TIMER
+#ifdef CONFIG_ETRAX_SERIAL_FAST_TIMER
+	memset(fast_timers, 0, sizeof(fast_timers));
+#endif
+#ifdef CONFIG_ETRAX_RS485
+	memset(fast_timers_rs485, 0, sizeof(fast_timers_rs485));
+#endif
+	fast_timer_init();
+#endif
+
+#ifndef CONFIG_SVINTO_SIM
+#ifndef CONFIG_ETRAX_KGDB
+	/* Not needed in simulator.  May only complicate stuff. */
+	/* hook the irq's for DMA channel 6 and 7, serial output and input, and some more... */
+
+	if (request_irq(SERIAL_IRQ_NBR, ser_interrupt,
+			IRQF_SHARED | IRQF_DISABLED, "serial ", driver))
+		panic("%s: Failed to request irq8", __func__);
+
+#endif
+#endif /* CONFIG_SVINTO_SIM */
+
+	return 0;
+}
+
+/* this makes sure that rs_init is called during kernel boot */
+
+module_init(rs_init);