patch-2.1.15 linux/drivers/char/esp.c

• Lines: 2583
• Date: Wed Dec 11 17:16:07 1996
• Orig file: v2.1.14/linux/drivers/char/esp.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.14/linux/drivers/char/esp.c linux/drivers/char/esp.c
@@ -0,0 +1,2582 @@
+/*
+ *  esp.c - driver for Hayes ESP serial cards
+ *
+ *  --- Notices from serial.c, upon which this driver is based ---
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Extensively rewritten by Theodore Ts'o, 8/16/92 -- 9/14/92.  Now
+ *  much more extensible to support other serial cards based on the
+ *  16450/16550A UART's.  Added support for the AST FourPort and the
+ *  Accent Async board.  
+ *
+ *  set_serial_info fixed to set the flags, custom divisor, and uart
+ * 	type fields.  Fix suggested by Michael K. Johnson 12/12/92.
+ *
+ *  11/95: TIOCMIWAIT, TIOCGICOUNT by Angelo Haritsis <ah@doc.ic.ac.uk>
+ *
+ *  03/96: Modularised by Angelo Haritsis <ah@doc.ic.ac.uk>
+ *
+ *  rs_set_termios fixed to look also for changes of the input
+ *      flags INPCK, BRKINT, PARMRK, IGNPAR and IGNBRK.
+ *                                            Bernd Anhäupl 05/17/96.
+ *
+ * --- End of notices from serial.c ---
+ *
+ * Support for the ESP serial card by Andrew J. Robinson
+ *     <arobinso@nyx.net> (Card detection routine taken from a patch
+ *     by Dennis J. Boylan).  Patches to allow use with 2.1.x contributed
+ *     by Chris Faylor.
+ *
+ * This module exports the following rs232 io functions:
+ *
+ *	int esp_init(void);
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/config.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/segment.h>
+#include <asm/bitops.h>
+
+#include <asm/dma.h>
+#include <linux/malloc.h>
+#include <asm/uaccess.h>
+
+#include "esp.h"
+
+#define NR_PORTS 64	/* maximum number of ports */
+#define NR_PRIMARY 8	/* maximum number of primary ports */
+
+/* The following variables can be set by giving module options */
+static int irq[NR_PRIMARY] = {0,0,0,0,0,0,0,0};	/* IRQ for each base port */
+static unsigned int divisor[NR_PRIMARY] = {0,0,0,0,0,0,0,0};
+	/* custom divisor for each port */
+static unsigned int dma = CONFIG_ESP_DMA_CHANNEL; /* DMA channel */
+static unsigned int trigger = CONFIG_ESP_TRIGGER_LEVEL; /* FIFO trigger level */
+/* END */
+
+static char *dma_buffer;
+
+#define DMA_BUFFER_SZ 1024
+
+#define WAKEUP_CHARS 1024
+
+static char *serial_name = "ESP driver";
+static char *serial_version = "1.0";
+
+DECLARE_TASK_QUEUE(tq_esp);
+
+static struct tty_driver esp_driver, esp_callout_driver;
+static int serial_refcount;
+
+/* serial subtype definitions */
+#define SERIAL_TYPE_NORMAL	1
+#define SERIAL_TYPE_CALLOUT	2
+
+/*
+ * Serial driver configuration section.  Here are the various options:
+ *
+ * SERIAL_PARANOIA_CHECK
+ * 		Check the magic number for the esp_structure where
+ * 		ever possible.
+ */
+
+#undef SERIAL_PARANOIA_CHECK
+#define SERIAL_DO_RESTART
+
+#undef SERIAL_DEBUG_INTR
+#undef SERIAL_DEBUG_OPEN
+#undef SERIAL_DEBUG_FLOW
+
+#define _INLINE_ inline
+  
+#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
+#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
+ kdevname(tty->device), (info->flags), serial_refcount,info->count,tty->count,s)
+#else
+#define DBG_CNT(s)
+#endif
+
+static struct esp_struct *IRQ_ports[16];
+
+static void autoconfig(struct esp_struct * info);
+static void change_speed(struct esp_struct *info);
+	
+/*
+ * This assumes you have a 1.8432 MHz clock for your UART.
+ *
+ * It'd be nice if someone built a serial card with a 24.576 MHz
+ * clock, since the 16550A is capable of handling a top speed of 1.5
+ * megabits/second; but this requires the faster clock.
+ */
+#define BASE_BAUD ((1843200 / 16) * (1 << ESPC_SCALE))
+
+/* Standard COM flags (except for COM4, because of the 8514 problem) */
+#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
+
+static struct tty_struct *serial_table[NR_PORTS];
+static struct termios *serial_termios[NR_PORTS];
+static struct termios *serial_termios_locked[NR_PORTS];
+
+#ifndef MIN
+#define MIN(a,b)	((a) < (b) ? (a) : (b))
+#endif
+
+/*
+ * 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 = 0;
+static struct semaphore tmp_buf_sem = MUTEX;
+
+static inline int serial_paranoia_check(struct esp_struct *info,
+					kdev_t device, const char *routine)
+{
+#ifdef SERIAL_PARANOIA_CHECK
+	static const char *badmagic =
+		"Warning: bad magic number for serial struct (%s) in %s\n";
+	static const char *badinfo =
+		"Warning: null esp_struct for (%s) in %s\n";
+
+	if (!info) {
+		printk(badinfo, kdevname(device), routine);
+		return 1;
+	}
+	if (info->magic != ESP_MAGIC) {
+		printk(badmagic, kdevname(device), routine);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/*
+ * This is used to figure out the divisor speeds and the timeouts
+ */
+static int baud_table[] = {
+	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+	9600, 19200, 38400, 57600, 115200, 230400, 460800, 0 };
+
+static inline unsigned int serial_in(struct esp_struct *info, int offset)
+{
+	return inb(info->port + offset);
+}
+
+static inline void serial_out(struct esp_struct *info, int offset, int value)
+{
+	outb(value, info->port+offset);
+}
+
+static inline int __get_order(unsigned long size)
+{
+	int order;
+
+	size = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
+	order = -1;
+	do {
+		size >>= 1;
+		order++;
+	} while (size);
+
+	return order;
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_stop() and rs_start()
+ *
+ * This routines are called before setting or resetting tty->stopped.
+ * They enable or disable transmitter interrupts, as necessary.
+ * ------------------------------------------------------------
+ */
+static void rs_stop(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->device, "rs_stop"))
+		return;
+	
+	save_flags(flags); cli();
+	if (info->IER & UART_IER_THRI) {
+		info->IER &= ~UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+	}
+
+	restore_flags(flags);
+}
+
+static void rs_start(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+	
+	if (serial_paranoia_check(info, tty->device, "rs_start"))
+		return;
+	
+	save_flags(flags); cli();
+	if (info->xmit_cnt && info->xmit_buf && !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+	}
+	restore_flags(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 _INLINE_ void rs_sched_event(struct esp_struct *info,
+				  int event)
+{
+	info->event |= 1 << event;
+	queue_task_irq_off(&info->tqueue, &tq_esp);
+	mark_bh(ESP_BH);
+}
+
+static _INLINE_ void receive_chars_dma(struct esp_struct *info, int *dma_bytes,
+	int *dma_direction, unsigned int *who_dma)
+{
+	unsigned int num_chars;
+
+        if (*dma_bytes) {
+		info->stat_flags |= STAT_NEED_DMA;
+        	return;
+	}
+
+	info->stat_flags &= ~(STAT_RX_TIMEOUT | STAT_NEED_DMA);
+
+	serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
+	serial_out(info, UART_ESI_CMD1, ESI_GET_RX_AVAIL);
+	num_chars = serial_in(info, UART_ESI_STAT1) << 8;
+	num_chars |= serial_in(info, UART_ESI_STAT2);
+
+	if (!num_chars)
+		return;
+        
+        *dma_bytes = num_chars;
+	*dma_direction = DMA_MODE_READ;
+	*who_dma = info->port;
+        disable_dma(dma);
+        clear_dma_ff(dma);
+        set_dma_mode(dma, DMA_MODE_READ);
+        set_dma_addr(dma, virt_to_bus(dma_buffer));
+        set_dma_count(dma, num_chars);
+        enable_dma(dma);
+        serial_out(info, UART_ESI_CMD1, ESI_START_DMA_RX);
+}
+
+static void do_ttybuf(void *private_)
+{
+	struct esp_struct	*info = (struct esp_struct *) private_;
+	struct tty_struct	*tty;
+	int avail_bytes, x_bytes;
+	unsigned long int flags;
+
+	save_flags(flags); cli();
+	tty = info->tty;
+
+	if (!tty) {
+		restore_flags(flags);
+		return;
+	}
+
+	avail_bytes = TTY_FLIPBUF_SIZE - tty->flip.count;
+
+	if (avail_bytes) {
+		if (info->tty_buf->count < avail_bytes)
+			x_bytes = info->tty_buf->count;
+		else
+			x_bytes = avail_bytes;
+
+		tty->flip.count += x_bytes;
+		memcpy(tty->flip.char_buf_ptr, info->tty_buf->char_buf,
+			x_bytes);
+		memcpy(tty->flip.flag_buf_ptr, info->tty_buf->flag_buf,
+			x_bytes);
+		tty->flip.char_buf_ptr += x_bytes;
+		tty->flip.flag_buf_ptr += x_bytes;
+		info->tty_buf->count -= x_bytes;
+		info->tty_buf->char_buf_ptr -= x_bytes;
+		info->tty_buf->flag_buf_ptr -= x_bytes;
+
+		if (info->tty_buf->count) {
+			memmove(info->tty_buf->char_buf,
+				info->tty_buf->char_buf + x_bytes,
+				info->tty_buf->count);
+			queue_task_irq_off(&info->tty_buf->tqueue,
+						&tq_timer);
+		}
+
+		queue_task_irq_off(&tty->flip.tqueue, &tq_timer);
+	} else {
+		queue_task_irq_off(&info->tty_buf->tqueue, &tq_timer);
+	}
+
+	restore_flags(flags);
+}
+
+static _INLINE_ void receive_chars_dma_done(struct esp_struct *info, 
+	int *dma_bytes, int *dma_direction, unsigned int *who_dma, int status)
+{
+	struct tty_struct *tty = info->tty;
+	int num_bytes, bytes_left, x_bytes;
+	struct tty_flip_buffer *buffer;
+
+	if (!(*dma_bytes) || (*who_dma != info->port))
+		return;
+
+	disable_dma(dma);
+	clear_dma_ff(dma);
+
+	num_bytes = *dma_bytes - get_dma_residue(dma);
+
+	buffer = &(tty->flip);
+	bytes_left = num_bytes;
+
+	if (info->tty_buf->count && (tty->flip.count < TTY_FLIPBUF_SIZE))
+		do_ttybuf(info);
+
+	while (bytes_left > 0) {
+		if ((buffer->count + bytes_left) > TTY_FLIPBUF_SIZE)
+			x_bytes = TTY_FLIPBUF_SIZE - buffer->count;
+		else
+			x_bytes = bytes_left;
+
+		memcpy(buffer->char_buf_ptr,
+			 dma_buffer + (num_bytes - bytes_left), x_bytes);
+		buffer->char_buf_ptr += x_bytes;
+		buffer->count += x_bytes;
+		memset(buffer->flag_buf_ptr, 0, x_bytes);
+		buffer->flag_buf_ptr += x_bytes;
+		bytes_left -= x_bytes;
+
+		if (bytes_left > 0) {
+			if (buffer == info->tty_buf)
+				break;
+			else
+				buffer = info->tty_buf;
+		}
+	}
+
+	if (num_bytes > 0) {
+		buffer->flag_buf_ptr--;
+
+		status >>= 8;
+		status &= (0x1c & info->read_status_mask);
+
+		if (status & info->ignore_status_mask) {
+			buffer->count--;
+			buffer->char_buf_ptr--;
+			buffer->flag_buf_ptr--;
+		} else if (status & 0x10) {
+			*buffer->flag_buf_ptr = TTY_BREAK;
+			if (info->flags & ASYNC_SAK)
+				do_SAK(tty);
+		} else if (status & 0x08)
+			*buffer->flag_buf_ptr = TTY_FRAME;
+		else if (status & 0x04)
+			*buffer->flag_buf_ptr = TTY_PARITY;
+	
+		buffer->flag_buf_ptr++;
+		
+		if (buffer == info->tty_buf)
+			queue_task_irq_off(&info->tty_buf->tqueue, &tq_timer);
+
+		queue_task_irq_off(&tty->flip.tqueue, &tq_timer);
+	}
+
+	if (*dma_bytes != num_bytes) {
+		*dma_bytes = 0;
+		receive_chars_dma(info, dma_bytes, dma_direction, who_dma);
+	} else
+		*dma_bytes = 0;
+}
+
+static _INLINE_ void transmit_chars_dma(struct esp_struct *info, int *dma_bytes,
+	int *dma_direction, unsigned int *who_dma)
+{
+	int count;
+	
+	if (*dma_bytes) {
+		info->stat_flags |= STAT_NEED_DMA;
+		return;
+	}
+
+	info->stat_flags &= ~STAT_NEED_DMA;
+
+	if ((info->xmit_cnt <= 0) || info->tty->stopped ||
+    		info->tty->hw_stopped) {
+		info->IER &= ~UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+		return;
+	}
+	
+	serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
+	serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
+	count = serial_in(info, UART_ESI_STAT1) << 8;
+	count |= serial_in(info, UART_ESI_STAT2);
+
+	if (!count)
+		return;
+
+	count = ((count < info->xmit_cnt) ? count : info->xmit_cnt);
+
+	if (info->xmit_tail + count <= ESP_XMIT_SIZE) {
+		memcpy(dma_buffer, &(info->xmit_buf[info->xmit_tail]),
+			count);
+	} else {
+		int i = ESP_XMIT_SIZE - info->xmit_tail;
+		memcpy(dma_buffer, &(info->xmit_buf[info->xmit_tail]),
+			i);
+		memcpy(&(dma_buffer[i]), info->xmit_buf, count - i);
+	}
+
+	info->xmit_cnt -= count;
+	info->xmit_tail = (info->xmit_tail + count) & (ESP_XMIT_SIZE - 1);
+
+	if (info->xmit_cnt < WAKEUP_CHARS)
+		rs_sched_event(info, ESP_EVENT_WRITE_WAKEUP);
+
+#ifdef SERIAL_DEBUG_INTR
+		printk("THRE...");
+#endif
+
+	if (info->xmit_cnt <= 0) {
+		info->IER &= ~UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+	}
+
+        *dma_bytes = count;
+	*dma_direction = DMA_MODE_WRITE;
+	*who_dma = info->port;
+        disable_dma(dma);
+        clear_dma_ff(dma);
+        set_dma_mode(dma, DMA_MODE_WRITE);
+        set_dma_addr(dma, virt_to_bus(dma_buffer));
+        set_dma_count(dma, count);
+        enable_dma(dma);
+        serial_out(info, UART_ESI_CMD1, ESI_START_DMA_TX);
+}
+
+static _INLINE_ void transmit_chars_dma_done(struct esp_struct *info,
+	int *dma_bytes, int *dma_direction, unsigned int *who_dma)
+{
+	int num_bytes;
+
+	if (!(*dma_bytes) || (*who_dma != info->port))
+		return;
+
+	disable_dma(dma);
+	clear_dma_ff(dma);
+
+	num_bytes = *dma_bytes - get_dma_residue(dma);
+
+	if (*dma_bytes != num_bytes)
+	{
+		*dma_bytes -= num_bytes;
+		memmove(dma_buffer, dma_buffer + num_bytes, *dma_bytes);
+		*dma_direction = DMA_MODE_WRITE;
+        	disable_dma(dma);
+        	clear_dma_ff(dma);
+        	set_dma_mode(dma, DMA_MODE_WRITE);
+        	set_dma_addr(dma, virt_to_bus(dma_buffer));
+        	set_dma_count(dma, *dma_bytes);
+        	enable_dma(dma);
+        	serial_out(info, UART_ESI_CMD1, ESI_START_DMA_TX);
+	} else
+		*dma_bytes = 0;
+}
+
+static _INLINE_ void check_modem_status(struct esp_struct *info)
+{
+	int	status;
+	
+	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
+	status = serial_in(info, UART_ESI_STAT2);
+
+	if (status & UART_MSR_ANY_DELTA) {
+		/* update input line counters */
+		if (status & UART_MSR_TERI)
+			info->icount.rng++;
+		if (status & UART_MSR_DDSR)
+			info->icount.dsr++;
+		if (status & UART_MSR_DDCD)
+			info->icount.dcd++;
+		if (status & UART_MSR_DCTS)
+			info->icount.cts++;
+		wake_up_interruptible(&info->delta_msr_wait);
+	}
+
+	if ((info->flags & ASYNC_CHECK_CD) && (status & UART_MSR_DDCD)) {
+#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
+		printk("ttys%d CD now %s...", info->line,
+		       (status & UART_MSR_DCD) ? "on" : "off");
+#endif		
+		if (status & UART_MSR_DCD)
+			wake_up_interruptible(&info->open_wait);
+		else if (!((info->flags & ASYNC_CALLOUT_ACTIVE) &&
+			   (info->flags & ASYNC_CALLOUT_NOHUP))) {
+#ifdef SERIAL_DEBUG_OPEN
+			printk("scheduling hangup...");
+#endif
+			queue_task_irq_off(&info->tqueue_hangup,
+					   &tq_scheduler);
+		}
+	}
+}
+
+static _INLINE_ void tx_flowed_on(struct esp_struct *info)
+{
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+	printk("CTS tx start...");
+#endif
+	info->tty->hw_stopped = 0;
+	info->IER |= UART_IER_THRI;
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK); /* set mask */
+	serial_out(info, UART_ESI_CMD2, info->IER);
+	rs_sched_event(info, ESP_EVENT_WRITE_WAKEUP);
+}
+
+static _INLINE_ void tx_flowed_off(struct esp_struct *info)
+{
+#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
+	printk("CTS tx stop...");
+#endif
+	info->tty->hw_stopped = 1;
+	info->IER &= ~UART_IER_THRI;
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK); /* set mask */
+	serial_out(info, UART_ESI_CMD2, info->IER);
+}
+
+/*
+ * This is the serial driver's interrupt routine for a single port
+ */
+static void rs_interrupt_single(int irq, void *dev_id, struct pt_regs * regs)
+{
+	struct esp_struct * info, *stop_port;
+	unsigned err_status;
+	unsigned int scratch;
+	int pre_bytes;
+	int check_dma_only = 0;
+	static int dma_bytes;
+	static int dma_direction;
+	static int who_dma;
+	
+#ifdef SERIAL_DEBUG_INTR
+	printk("rs_interrupt_single(%d)...", irq);
+#endif
+	
+	/* This routine will currently check ALL ports when an interrupt */
+	/* is received from ANY port */
+
+	stop_port = info = IRQ_ports[irq];
+
+	if (!info)
+		return;
+
+	do {
+		if (!info->tty || (check_dma_only &&
+			!(info->stat_flags & STAT_NEED_DMA))) {
+			info = info->next_port;
+			continue;
+		}
+
+		pre_bytes = dma_bytes;
+		err_status = 0;
+		scratch = serial_in(info, UART_ESI_SID);
+		if (scratch & 0x04) { /* error - check for rx timeout */
+			serial_out(info, UART_ESI_CMD1, ESI_GET_ERR_STAT);
+			err_status = serial_in(info, UART_ESI_STAT1) << 8;
+			err_status |= serial_in(info, UART_ESI_STAT2);
+
+			if (err_status & 0x0100)
+				info->stat_flags |= STAT_RX_TIMEOUT;
+
+			if (err_status & 0x2000)	/* UART status */
+				check_modem_status(info);
+
+			if (err_status & 0x8000)	/* Start break */
+				wake_up_interruptible(&info->break_wait);
+
+			if (err_status & 0x0002)	/* tx off */
+				tx_flowed_off(info);
+
+			if (err_status & 0x0004)	/* tx on */
+				tx_flowed_on(info);
+		}
+		
+		if ((scratch & 0x88)  || /* DMA completed or timed out */
+			(err_status & 0x1c00) /* receive error */)
+			if (dma_direction == DMA_MODE_READ)
+				receive_chars_dma_done(info, &dma_bytes,
+					&dma_direction, &who_dma, err_status);
+			else
+				transmit_chars_dma_done(info, &dma_bytes,
+					&dma_direction, &who_dma);
+
+		if (((scratch & 0x01) ||
+			(info->stat_flags & STAT_RX_TIMEOUT)) &&
+			(info->IER & UART_IER_RDI))
+			receive_chars_dma(info, &dma_bytes, &dma_direction,
+				&who_dma);
+
+		if ((scratch & 0x02) && (info->IER & UART_IER_THRI))
+			transmit_chars_dma(info, &dma_bytes, &dma_direction,
+				&who_dma);
+
+		info->last_active = jiffies;
+
+		if (pre_bytes && !dma_bytes)  /* released DMA */
+			stop_port = info;
+
+		info = info->next_port;
+
+		if ((info->irq != irq) || (info == IRQ_ports[irq]))
+			check_dma_only = 1;
+
+		if (check_dma_only && dma_bytes)
+			info = stop_port;
+	} while (info != stop_port);
+
+#ifdef SERIAL_DEBUG_INTR
+	printk("end.\n");
+#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_serial_bh(void)
+{
+	run_task_queue(&tq_esp);
+}
+
+static void do_softint(void *private_)
+{
+	struct esp_struct	*info = (struct esp_struct *) private_;
+	struct tty_struct	*tty;
+	
+	tty = info->tty;
+	if (!tty)
+		return;
+
+	if (clear_bit(ESP_EVENT_WRITE_WAKEUP, &info->event)) {
+		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+		    tty->ldisc.write_wakeup)
+			(tty->ldisc.write_wakeup)(tty);
+		wake_up_interruptible(&tty->write_wait);
+	}
+}
+
+/*
+ * This routine is called from the scheduler tqueue when the interrupt
+ * routine has signalled that a hangup has occurred.  The path of
+ * hangup processing is:
+ *
+ * 	serial interrupt routine -> (scheduler tqueue) ->
+ * 	do_serial_hangup() -> tty->hangup() -> esp_hangup()
+ * 
+ */
+static void do_serial_hangup(void *private_)
+{
+	struct esp_struct	*info = (struct esp_struct *) private_;
+	struct tty_struct	*tty;
+	
+	tty = info->tty;
+	if (!tty)
+		return;
+
+	tty_hangup(tty);
+}
+
+/*
+ * ---------------------------------------------------------------
+ * Low level utility subroutines for the serial driver:  routines to
+ * figure out the appropriate timeout for an interrupt chain, routines
+ * to initialize and startup a serial port, and routines to shutdown a
+ * serial port.  Useful stuff like that.
+ * ---------------------------------------------------------------
+ */
+
+static void esp_basic_init(struct esp_struct * info)
+{
+	/* put ESPC in enhanced mode */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_MODE);
+	serial_out(info, UART_ESI_CMD2, 0x31);
+
+	/* disable interrupts for now */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+	serial_out(info, UART_ESI_CMD2, 0x00);
+
+	/* set interrupt and DMA channel */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_IRQ);
+	serial_out(info, UART_ESI_CMD2, (dma << 4) | 0x01);
+	serial_out(info, UART_ESI_CMD1, ESI_SET_ENH_IRQ);
+	if (info->line % 8)	/* secondary port */
+		serial_out(info, UART_ESI_CMD2, 0x0d);	/* shared */
+	else if (info->irq == 9)
+		serial_out(info, UART_ESI_CMD2, 0x02);
+	else
+		serial_out(info, UART_ESI_CMD2, info->irq);
+
+	/* set error status mask (check this) */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_ERR_MASK);
+	serial_out(info, UART_ESI_CMD2, 0xbd);
+	serial_out(info, UART_ESI_CMD2, 0x06);
+
+	/* set DMA timeout */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_DMA_TMOUT);
+	serial_out(info, UART_ESI_CMD2, 0xff);
+
+	/* set FIFO trigger levels */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_TRIGGER);
+	serial_out(info, UART_ESI_CMD2, trigger / 256);
+	serial_out(info, UART_ESI_CMD2, trigger % 256);
+	serial_out(info, UART_ESI_CMD2, trigger / 256);
+	serial_out(info, UART_ESI_CMD2, trigger % 256);
+
+	/* Set clock scaling */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_PRESCALAR);
+	serial_out(info, UART_ESI_CMD2, ESPC_SCALE);
+}
+
+static int startup(struct esp_struct * info)
+{
+	unsigned long flags;
+	int	retval;
+	int next_irq;
+	struct esp_struct *next_info = 0;
+        unsigned int num_chars;
+
+	save_flags(flags); cli();
+
+	if (info->flags & ASYNC_INITIALIZED) {
+		restore_flags(flags);
+		return 0;
+	}
+
+	if (!info->port || !info->type) {
+		if (info->tty)
+			set_bit(TTY_IO_ERROR, &info->tty->flags);
+		restore_flags(flags);
+		return 0;
+	}
+
+	if (!info->xmit_buf) {
+		info->xmit_buf = (unsigned char *)get_free_page(GFP_KERNEL);
+		if (!info->xmit_buf) {
+			restore_flags(flags);
+			return -ENOMEM;
+		}
+	}
+
+	if (!info->tty_buf) {
+		info->tty_buf = (struct tty_flip_buffer *)kmalloc(
+			sizeof(struct tty_flip_buffer), GFP_KERNEL);
+
+		if (!info->tty_buf) {
+			free_page((unsigned long) info->xmit_buf);
+			info->xmit_buf = 0;
+			restore_flags(flags);
+			return -ENOMEM;
+		}
+
+		memset(info->tty_buf, 0, sizeof(struct tty_flip_buffer));
+		info->tty_buf->tqueue.routine = do_ttybuf;
+		info->tty_buf->tqueue.data = info;
+	} 
+
+	info->tty_buf->count = 0;
+	info->tty_buf->char_buf_ptr = info->tty_buf->char_buf;
+	info->tty_buf->flag_buf_ptr = info->tty_buf->flag_buf;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("starting up ttys%d (irq %d)...", info->line, info->irq);
+#endif
+
+	/* Flush the RX buffer.  Using the ESI flush command may cause */
+	/* wild interrupts, so read all the data instead. */
+
+	serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
+	serial_out(info, UART_ESI_CMD1, ESI_GET_RX_AVAIL);
+	num_chars = serial_in(info, UART_ESI_STAT1) << 8;
+	num_chars |= serial_in(info, UART_ESI_STAT2);
+
+	while (num_chars > 1) {
+		inw(info->port + UART_ESI_RX);
+		num_chars -= 2;
+	}
+
+	if (num_chars)
+		serial_in(info, UART_ESI_RX);
+
+	/* set receive character timeout */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
+	serial_out(info, UART_ESI_CMD2, 0xff);
+
+	info->stat_flags = 0;
+
+	/*
+	 * Allocate the IRQ if necessary
+	 */
+	if (!IRQ_ports[info->irq]) {
+		retval = request_irq(info->irq, rs_interrupt_single,
+					SA_INTERRUPT, "esp", NULL);
+
+		if (!retval) {
+			int i = 1;
+
+			while ((i < 16) && !IRQ_ports[i])
+				i++;	
+
+			if (i == 16) {
+				dma_buffer = (char *)__get_dma_pages(GFP_KERNEL,
+					__get_order(DMA_BUFFER_SZ));
+
+				if (!dma_buffer)
+					retval = -ENOMEM;
+				else
+					retval = request_dma(dma, "esp");
+
+				if (retval)
+					free_irq(info->irq, NULL);
+			}
+		}
+
+		if (retval) {
+			restore_flags(flags);
+			if (suser()) {
+				if (info->tty)
+					set_bit(TTY_IO_ERROR,
+						&info->tty->flags);
+				return 0;
+			} else
+				return retval;
+		}
+	}
+
+	info->MCR = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
+	info->MCR_noint = UART_MCR_DTR | UART_MCR_RTS;
+#if defined(__alpha__) && !defined(CONFIG_PCI)
+	info->MCR |= UART_MCR_OUT1 | UART_MCR_OUT2;
+	info->MCR_noint |= UART_MCR_OUT1 | UART_MCR_OUT2;
+#endif
+
+	serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+	serial_out(info, UART_ESI_CMD2, UART_MCR);
+	serial_out(info, UART_ESI_CMD2, info->MCR);
+	
+	/*
+	 * Finally, enable interrupts
+	 */
+	/* info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI; */
+	info->IER = UART_IER_RLSI | UART_IER_RDI | UART_IER_DMA_TMOUT |
+			UART_IER_DMA_TC;
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+	serial_out(info, UART_ESI_CMD2, info->IER);
+	
+	if (info->tty)
+		clear_bit(TTY_IO_ERROR, &info->tty->flags);
+	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+
+	/* Remove port from "closed" chain */
+	if (info->next_port)
+		info->next_port->prev_port = info->prev_port;
+	if (info->prev_port)
+		info->prev_port->next_port = info->next_port;
+	else
+		IRQ_ports[0] = info->next_port;
+
+	/*
+	 * Insert serial port into IRQ chain.
+	 */
+	next_irq = info->irq;
+
+	do {
+		next_info = IRQ_ports[next_irq];
+		
+		if (++next_irq > 15)
+			next_irq = 1;
+	} while (!next_info && (next_irq != info->irq));
+
+	if (!next_info) {
+		info->next_port = info;
+		info->prev_port = info;
+	} else {
+		info->next_port = next_info;
+		info->prev_port = next_info->prev_port;
+		next_info->prev_port->next_port = info;
+		next_info->prev_port = info;
+	}
+
+	IRQ_ports[info->irq] = info;
+
+	/*
+	 * set the speed of the serial port
+	 */
+	change_speed(info);
+
+	info->flags |= ASYNC_INITIALIZED;
+	restore_flags(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 esp_struct * info)
+{
+	unsigned long	flags;
+
+	if (!(info->flags & ASYNC_INITIALIZED))
+		return;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("Shutting down serial port %d (irq %d)....", info->line,
+	       info->irq);
+#endif
+	
+	save_flags(flags); cli(); /* Disable interrupts */
+
+	/*
+	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
+	 * here so the queue might never be waken up
+	 */
+	wake_up_interruptible(&info->delta_msr_wait);
+	wake_up_interruptible(&info->break_wait);
+	
+	/*
+	 * First unlink the serial port from the IRQ chain...
+	 */
+	info->next_port->prev_port = info->prev_port;
+	info->prev_port->next_port = info->next_port;
+
+	if (IRQ_ports[info->irq] == info) {
+		if ((info->next_port == info) ||
+			(info->next_port->irq != info->irq))
+			IRQ_ports[info->irq] = 0;
+		else
+			IRQ_ports[info->irq] = info->next_port;
+	}
+
+	/* Stick it on the "closed" chain */
+	info->next_port = IRQ_ports[0];
+	if (info->next_port)
+		info->next_port->prev_port = info;
+	info->prev_port = 0;
+	IRQ_ports[0] = info;
+	
+	/*
+	 * Free the IRQ, if necessary
+	 */
+	if (!IRQ_ports[info->irq]) {
+		int i = 1;
+
+		while ((i < 16) && !IRQ_ports[i])
+			i++;
+
+		if (i == 16) {
+			free_dma(dma);
+			free_pages((unsigned int)dma_buffer, 
+				__get_order(DMA_BUFFER_SZ));
+			dma_buffer = 0;
+		}
+
+		free_irq(info->irq, NULL);
+	}
+
+	if (info->xmit_buf) {
+		free_page((unsigned long) info->xmit_buf);
+		info->xmit_buf = 0;
+	}
+
+	if (info->tty_buf && !info->tty_buf->tqueue.sync) {
+		kfree(info->tty_buf);
+		info->tty_buf = 0;
+	}
+
+	info->IER = 0;
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+	serial_out(info, UART_ESI_CMD2, 0x00);
+
+	if (!info->tty || (info->tty->termios->c_cflag & HUPCL)) {
+		info->MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
+		info->MCR_noint &= ~(UART_MCR_DTR|UART_MCR_RTS);
+	}
+
+	serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+	serial_out(info, UART_ESI_CMD2, UART_MCR);
+	serial_out(info, UART_ESI_CMD2, info->MCR_noint);
+
+	if (info->tty)
+		set_bit(TTY_IO_ERROR, &info->tty->flags);
+	
+	info->flags &= ~ASYNC_INITIALIZED;
+	restore_flags(flags);
+}
+
+/*
+ * This routine is called to set the UART divisor registers to match
+ * the specified baud rate for a serial port.
+ */
+static void change_speed(struct esp_struct *info)
+{
+	unsigned short port;
+	int	quot = 0;
+	unsigned cflag,cval;
+	int	i;
+	unsigned char flow1 = 0, flow2 = 0;
+
+	if (!info->tty || !info->tty->termios)
+		return;
+	cflag = info->tty->termios->c_cflag;
+	if (!(port = info->port))
+		return;
+	i = cflag & CBAUD;
+	if (i & CBAUDEX) {
+		i &= ~CBAUDEX;
+		if (i < 1 || i > 2) 
+			info->tty->termios->c_cflag &= ~CBAUDEX;
+		else
+			i += 15;
+	}
+	if (i == 15) {
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
+			i += 1;
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
+			i += 2;
+                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
+                        i += 3;
+                if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
+                        i += 4;
+		if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
+			quot = info->custom_divisor;
+	}
+	if (quot) {
+		info->timeout = ((1024*HZ*15*quot) /
+				 info->baud_base) + 2;
+	} else if (baud_table[i] == 134) {
+		quot = (2*info->baud_base / 269);
+		info->timeout = (1024*HZ*30/269) + 2;
+	} else if (baud_table[i]) {
+		quot = info->baud_base / baud_table[i];
+		info->timeout = (1024*HZ*15/baud_table[i]) + 2;
+	} else {
+		quot = 0;
+		info->timeout = 0;
+	}
+	if (quot) {
+		info->MCR |= UART_MCR_DTR;
+		info->MCR_noint |= UART_MCR_DTR;
+		cli();
+		serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+		serial_out(info, UART_ESI_CMD2, UART_MCR);
+		serial_out(info, UART_ESI_CMD2, info->MCR);
+		sti();
+	} else {
+		info->MCR &= ~UART_MCR_DTR;
+		info->MCR_noint &= ~UART_MCR_DTR;
+		cli();
+		serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+		serial_out(info, UART_ESI_CMD2, UART_MCR);
+		serial_out(info, UART_ESI_CMD2, info->MCR);
+		sti();
+		return;
+	}
+	/* byte size and parity */
+	switch (cflag & CSIZE) {
+	      case CS5: cval = 0x00; break;
+	      case CS6: cval = 0x01; break;
+	      case CS7: cval = 0x02; break;
+	      case CS8: cval = 0x03; break;
+	      default:  cval = 0x00; break;	/* too keep GCC shut... */
+	}
+	if (cflag & CSTOPB) {
+		cval |= 0x04;
+	}
+	if (cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+	
+	/* CTS flow control flag and modem status interrupts */
+	/* info->IER &= ~UART_IER_MSI; */
+	if (cflag & CRTSCTS) {
+		info->flags |= ASYNC_CTS_FLOW;
+		/* info->IER |= UART_IER_MSI; */
+		flow1 = 0x04;
+		flow2 = 0x10;
+	} else
+		info->flags &= ~ASYNC_CTS_FLOW;
+	if (cflag & CLOCAL)
+		info->flags &= ~ASYNC_CHECK_CD;
+	else {
+		info->flags |= ASYNC_CHECK_CD;
+		/* info->IER |= UART_IER_MSI; */
+	}
+
+	/*
+	 * Set up parity check flag
+	 */
+#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (I_INPCK(info->tty))
+		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
+		info->read_status_mask |= UART_LSR_BI;
+	
+	info->ignore_status_mask = 0;
+#if 0
+	/* This should be safe, but for some broken bits of hardware... */
+	if (I_IGNPAR(info->tty)) {
+		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+		info->read_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	}
+#endif
+	if (I_IGNBRK(info->tty)) {
+		info->ignore_status_mask |= UART_LSR_BI;
+		info->read_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignore parity and break indicators, ignore 
+		 * overruns too.  (For real raw support).
+		 */
+		if (I_IGNPAR(info->tty)) {
+			info->ignore_status_mask |= UART_LSR_OE | \
+				UART_LSR_PE | UART_LSR_FE;
+			info->read_status_mask |= UART_LSR_OE | \
+				UART_LSR_PE | UART_LSR_FE;
+		}
+	}
+
+	if (I_IXOFF(info->tty))
+		flow1 |= 0x81;
+
+	cli();
+	/* set baud */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_BAUD);
+	serial_out(info, UART_ESI_CMD2, quot >> 8);
+	serial_out(info, UART_ESI_CMD2, quot & 0xff);
+
+	/* set data bits, parity, etc. */
+	serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+	serial_out(info, UART_ESI_CMD2, UART_LCR);
+	serial_out(info, UART_ESI_CMD2, cval);
+
+	/* Enable flow control */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_CNTL);
+	serial_out(info, UART_ESI_CMD2, flow1);
+	serial_out(info, UART_ESI_CMD2, flow2);
+
+	/* set flow control characters (XON/XOFF only) */
+	if (I_IXOFF(info->tty)) {
+		serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_CHARS);
+		serial_out(info, UART_ESI_CMD2, START_CHAR(info->tty));
+		serial_out(info, UART_ESI_CMD2, STOP_CHAR(info->tty));
+		serial_out(info, UART_ESI_CMD2, 0x10);
+		serial_out(info, UART_ESI_CMD2, 0x21);
+		switch (cflag & CSIZE) {
+			case CS5:
+				serial_out(info, UART_ESI_CMD2, 0x1f);
+				break;
+			case CS6:
+				serial_out(info, UART_ESI_CMD2, 0x3f);
+				break;
+			case CS7:
+			case CS8:
+				serial_out(info, UART_ESI_CMD2, 0x7f);
+				break;
+			default:
+				serial_out(info, UART_ESI_CMD2, 0xff);
+				break;
+		}
+	}
+
+	/* Set high/low water */
+	serial_out(info, UART_ESI_CMD1, ESI_SET_FLOW_LVL);
+	serial_out(info, UART_ESI_CMD2, 0x03);
+	serial_out(info, UART_ESI_CMD2, 0xfc);
+	serial_out(info, UART_ESI_CMD2, (trigger + 4) / 256);
+	serial_out(info, UART_ESI_CMD2, (trigger + 4) % 256);
+
+	sti();
+}
+
+static void rs_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+
+	if (serial_paranoia_check(info, tty->device, "rs_put_char"))
+		return;
+
+	if (!tty || !info->xmit_buf)
+		return;
+
+	save_flags(flags); cli();
+	if (info->xmit_cnt >= ESP_XMIT_SIZE - 1) {
+		restore_flags(flags);
+		return;
+	}
+
+	info->xmit_buf[info->xmit_head++] = ch;
+	info->xmit_head &= ESP_XMIT_SIZE-1;
+	info->xmit_cnt++;
+	restore_flags(flags);
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+				
+	if (serial_paranoia_check(info, tty->device, "rs_flush_chars"))
+		return;
+
+	if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
+	    !info->xmit_buf)
+		return;
+
+	save_flags(flags); cli();
+	if (!(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+	}
+	restore_flags(flags);
+}
+
+static int rs_write(struct tty_struct * tty, int from_user,
+		    const unsigned char *buf, int count)
+{
+	int	c, total = 0;
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+				
+	if (serial_paranoia_check(info, tty->device, "rs_write"))
+		return 0;
+
+	if (!tty || !info->xmit_buf || !tmp_buf)
+		return 0;
+	    
+	if (from_user)
+		down(&tmp_buf_sem);
+	save_flags(flags);
+	while (1) {
+		cli();		
+		c = MIN(count, MIN(ESP_XMIT_SIZE - info->xmit_cnt - 1,
+				   ESP_XMIT_SIZE - info->xmit_head));
+		if (c <= 0)
+			break;
+
+		if (from_user) {
+			copy_from_user(tmp_buf, buf, c);
+			c = MIN(c, MIN(ESP_XMIT_SIZE - info->xmit_cnt - 1,
+				       ESP_XMIT_SIZE - info->xmit_head));
+			memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
+		} else
+			memcpy(info->xmit_buf + info->xmit_head, buf, c);
+		info->xmit_head = (info->xmit_head + c) & (ESP_XMIT_SIZE-1);
+		info->xmit_cnt += c;
+		restore_flags(flags);
+		buf += c;
+		count -= c;
+		total += c;
+	}
+	if (from_user)
+		up(&tmp_buf_sem);
+	if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped &&
+	    !(info->IER & UART_IER_THRI)) {
+		info->IER |= UART_IER_THRI;
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK); /* set mask */
+		serial_out(info, UART_ESI_CMD2, info->IER);
+	}
+	restore_flags(flags);
+	return total;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+	int	ret;
+				
+	if (serial_paranoia_check(info, tty->device, "rs_write_room"))
+		return 0;
+	ret = ESP_XMIT_SIZE - info->xmit_cnt - 1;
+	if (ret < 0)
+		ret = 0;
+	return ret;
+}
+
+static int rs_chars_in_buffer(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+				
+	if (serial_paranoia_check(info, tty->device, "rs_chars_in_buffer"))
+		return 0;
+	return info->xmit_cnt;
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+				
+	if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
+		return;
+	cli();
+	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+	sti();
+	wake_up_interruptible(&tty->write_wait);
+	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+	    tty->ldisc.write_wakeup)
+		(tty->ldisc.write_wakeup)(tty);
+}
+
+/*
+ * ------------------------------------------------------------
+ * 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 esp_struct *info = (struct esp_struct *)tty->driver_data;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+	
+	printk("throttle %s: %d....\n", _tty_name(tty, buf),
+	       tty->ldisc.chars_in_buffer(tty));
+#endif
+
+	if (serial_paranoia_check(info, tty->device, "rs_throttle"))
+		return;
+	
+	info->IER &= ~UART_IER_RDI;
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+	serial_out(info, UART_ESI_CMD2, info->IER);
+	serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
+	serial_out(info, UART_ESI_CMD2, 0x00);
+	sti();
+}
+
+static void rs_unthrottle(struct tty_struct * tty)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+#ifdef SERIAL_DEBUG_THROTTLE
+	char	buf[64];
+	
+	printk("unthrottle %s: %d....\n", _tty_name(tty, buf),
+	       tty->ldisc.chars_in_buffer(tty));
+#endif
+
+	if (serial_paranoia_check(info, tty->device, "rs_unthrottle"))
+		return;
+	
+	info->IER |= UART_IER_RDI;
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+	serial_out(info, UART_ESI_CMD2, info->IER);
+	serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
+	serial_out(info, UART_ESI_CMD2, 0xff);
+	sti();
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_ioctl() and friends
+ * ------------------------------------------------------------
+ */
+
+static int get_serial_info(struct esp_struct * info,
+			   struct serial_struct * retinfo)
+{
+	struct serial_struct tmp;
+  
+	if (!retinfo)
+		return -EFAULT;
+	memset(&tmp, 0, sizeof(tmp));
+	tmp.type = info->type;
+	tmp.line = info->line;
+	tmp.port = info->port;
+	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;
+	tmp.hub6 = 0;
+	copy_to_user(retinfo,&tmp,sizeof(*retinfo));
+	return 0;
+}
+
+static int set_serial_info(struct esp_struct * info,
+			   struct serial_struct * new_info)
+{
+	struct serial_struct new_serial;
+	struct esp_struct old_info;
+	unsigned int		change_irq;
+	int 			retval = 0;
+	struct esp_struct *current_async;
+	unsigned long flags = 0;
+
+	if (!new_info)
+		return -EFAULT;
+	copy_from_user(&new_serial,new_info,sizeof(new_serial));
+	old_info = *info;
+
+	if ((info->type != new_serial.type) ||
+		(new_serial.hub6) ||
+		(info->port != new_serial.port) ||
+		(info->baud_base != new_serial.baud_base) ||
+		(new_serial.irq > 15) ||
+		(new_serial.irq < 1))
+		return -EINVAL;
+
+	change_irq = new_serial.irq != info->irq;
+
+	if (change_irq && (info->line % 8))
+		return -EINVAL;
+
+	if (!suser()) {
+		if (change_irq || 
+		    (new_serial.baud_base != info->baud_base) ||
+		    (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));
+		info->custom_divisor = new_serial.custom_divisor;
+		goto check_and_exit;
+	}
+
+	if (new_serial.irq == 2)
+		new_serial.irq = 9;
+
+	if (change_irq) {
+		save_flags(flags); cli();
+
+		current_async = info;
+		do {
+			if ((current_async->line >= info->line) &&
+				(current_async->line < (info->line + 8))) {
+				if (current_async == info) {
+					if (current_async->count > 1) {
+						restore_flags(flags);
+						return -EBUSY;
+					}
+				} else {
+					restore_flags(flags);
+					return -EBUSY;
+				}
+			}
+			
+			current_async = current_async->next_port;
+		} while (current_async != info);
+	}
+
+	/*
+	 * 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->close_delay = new_serial.close_delay * HZ/100;
+	info->closing_wait = new_serial.closing_wait * HZ/100;
+
+	release_region(info->port,8);
+	if (change_irq) {
+		/*
+		 * We need to shutdown the serial port at the old
+		 * port/irq combination.
+		 */
+		shutdown(info);
+
+		current_async = IRQ_ports[0];
+		while (current_async != 0) {
+			if ((current_async->line >= info->line) &&
+				(current_async->line < (info->line + 8)))
+				current_async->irq = new_serial.irq;
+
+			current_async = current_async->next_port;
+		}
+
+		serial_out(info, UART_ESI_CMD1, ESI_SET_ENH_IRQ);
+		if (info->irq == 9)
+			serial_out(info, UART_ESI_CMD2, 0x02);
+		else
+			serial_out(info, UART_ESI_CMD2, info->irq);
+
+		restore_flags(flags);
+	}
+	if(info->type != PORT_UNKNOWN)
+		request_region(info->port,8,"esp(set)");
+
+	
+check_and_exit:
+	if (!info->port || !info->type)
+		return 0;
+	if (info->flags & ASYNC_INITIALIZED) {
+		if (((old_info.flags & ASYNC_SPD_MASK) !=
+		     (info->flags & ASYNC_SPD_MASK)) ||
+		    (old_info.custom_divisor != info->custom_divisor))
+			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 esp_struct * info, unsigned int *value)
+{
+	unsigned char status;
+	unsigned int result;
+
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
+	status = serial_in(info, UART_ESI_STAT1);
+	sti();
+	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
+	return put_user(result,value);
+}
+
+
+static int get_modem_info(struct esp_struct * info, unsigned int *value)
+{
+	unsigned char control, status;
+	unsigned int result;
+
+	control = info->MCR;
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
+	status = serial_in(info, UART_ESI_STAT2);
+	sti();
+	result =  ((control & UART_MCR_RTS) ? TIOCM_RTS : 0)
+		| ((control & UART_MCR_DTR) ? TIOCM_DTR : 0)
+		| ((status  & UART_MSR_DCD) ? TIOCM_CAR : 0)
+		| ((status  & UART_MSR_RI) ? TIOCM_RNG : 0)
+		| ((status  & UART_MSR_DSR) ? TIOCM_DSR : 0)
+		| ((status  & UART_MSR_CTS) ? TIOCM_CTS : 0);
+	return put_user(result,value);
+}
+
+static int set_modem_info(struct esp_struct * info, unsigned int cmd,
+			  unsigned int *value)
+{
+	int error;
+	unsigned int arg;
+
+	error = get_user(arg, value);
+	if (error)
+		return error;
+
+	switch (cmd) {
+	case TIOCMBIS: 
+		if (arg & TIOCM_RTS) {
+			info->MCR |= UART_MCR_RTS;
+			info->MCR_noint |= UART_MCR_RTS;
+		}
+		if (arg & TIOCM_DTR) {
+			info->MCR |= UART_MCR_DTR;
+			info->MCR_noint |= UART_MCR_DTR;
+		}
+		break;
+	case TIOCMBIC:
+		if (arg & TIOCM_RTS) {
+			info->MCR &= ~UART_MCR_RTS;
+			info->MCR_noint &= ~UART_MCR_RTS;
+		}
+		if (arg & TIOCM_DTR) {
+			info->MCR &= ~UART_MCR_DTR;
+			info->MCR_noint &= ~UART_MCR_DTR;
+		}
+		break;
+	case TIOCMSET:
+		info->MCR = ((info->MCR & ~(UART_MCR_RTS | UART_MCR_DTR))
+			     | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
+			     | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
+		info->MCR_noint = ((info->MCR_noint
+				    & ~(UART_MCR_RTS | UART_MCR_DTR))
+				   | ((arg & TIOCM_RTS) ? UART_MCR_RTS : 0)
+				   | ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
+		break;
+	default:
+		return -EINVAL;
+	}
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+	serial_out(info, UART_ESI_CMD2, UART_MCR);
+	serial_out(info, UART_ESI_CMD2, info->MCR);
+	sti();
+	return 0;
+}
+
+static int do_autoconfig(struct esp_struct * info)
+{
+	int			retval;
+	
+	if (!suser())
+		return -EPERM;
+	
+	if (info->count > 1)
+		return -EBUSY;
+	
+	shutdown(info);
+
+	cli();
+	autoconfig(info);
+	sti();
+
+	retval = startup(info);
+	if (retval)
+		return retval;
+	return 0;
+}
+
+
+/*
+ * This routine sends a break character out the serial port.
+ */
+static void send_break(	struct esp_struct * info, int duration)
+{
+	if (!info->port)
+		return;
+	cli();
+	serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
+	serial_out(info, UART_ESI_CMD2, 0x01);
+
+	interruptible_sleep_on(&info->break_wait);
+
+	current->state = TASK_INTERRUPTIBLE;
+	current->timeout = jiffies + duration;
+	schedule();
+
+	serial_out(info, UART_ESI_CMD1, ESI_ISSUE_BREAK);
+	serial_out(info, UART_ESI_CMD2, 0x00);
+	sti();
+}
+
+static int rs_ioctl(struct tty_struct *tty, struct file * file,
+		    unsigned int cmd, unsigned long arg)
+{
+	int error;
+	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
+	int retval;
+	struct async_icount cprev, cnow;	/* kernel counter temps */
+	struct serial_icounter_struct *p_cuser;	/* user space */
+
+	if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
+		return -ENODEV;
+
+	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
+	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT) &&
+	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
+		if (tty->flags & (1 << TTY_IO_ERROR))
+		    return -EIO;
+	}
+	
+	switch (cmd) {
+		case TCSBRK:	/* SVID version: non-zero arg --> no break */
+			retval = tty_check_change(tty);
+			if (retval)
+				return retval;
+			tty_wait_until_sent(tty, 0);
+			if (!arg)
+				send_break(info, HZ/4);	/* 1/4 second */
+			return 0;
+		case TCSBRKP:	/* support for POSIX tcsendbreak() */
+			retval = tty_check_change(tty);
+			if (retval)
+				return retval;
+			tty_wait_until_sent(tty, 0);
+			send_break(info, arg ? arg*(HZ/10) : HZ/4);
+			return 0;
+		case TIOCGSOFTCAR:
+			return put_user(C_CLOCAL(tty) ? 1 : 0,
+				    (int *) arg);
+		case TIOCSSOFTCAR:
+			error = get_user(arg, (unsigned int *)arg);
+			if (error)
+				return error;
+			tty->termios->c_cflag =
+				((tty->termios->c_cflag & ~CLOCAL) |
+				 (arg ? CLOCAL : 0));
+			return 0;
+		case TIOCMGET:
+			return get_modem_info(info, (unsigned int *) arg);
+		case TIOCMBIS:
+		case TIOCMBIC:
+		case TIOCMSET:
+			return set_modem_info(info, cmd, (unsigned int *) arg);
+		case TIOCGSERIAL:
+			error = verify_area(VERIFY_WRITE, (void *) arg,
+						sizeof(struct serial_struct));
+			if (error)
+				return error;
+			return get_serial_info(info,
+					       (struct serial_struct *) arg);
+		case TIOCSSERIAL:
+			error = verify_area(VERIFY_READ, (void *) arg,
+						sizeof(struct serial_struct));
+			if (error)
+				return error;
+			return set_serial_info(info,
+					       (struct serial_struct *) arg);
+		case TIOCSERCONFIG:
+			return do_autoconfig(info);
+
+		case TIOCSERGWILD:
+			return put_user(0L, (unsigned long *) arg);
+
+		case TIOCSERGETLSR: /* Get line status register */
+			    return get_lsr_info(info, (unsigned int *) arg);
+
+		case TIOCSERSWILD:
+			if (!suser())
+				return -EPERM;
+			return 0;
+
+		/*
+		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
+		 * - mask passed in arg for lines of interest
+ 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
+		 * Caller should use TIOCGICOUNT to see which one it was
+		 */
+		 case TIOCMIWAIT:
+			cli();
+			cprev = info->icount;	/* note the counters on entry */
+			sti();
+			while (1) {
+				interruptible_sleep_on(&info->delta_msr_wait);
+				/* see if a signal did it */
+				if (current->signal & ~current->blocked)
+					return -ERESTARTSYS;
+				cli();
+				cnow = info->icount;	/* atomic copy */
+				sti();
+				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
+				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
+					return -EIO; /* no change => error */
+				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
+				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
+				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
+				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
+					return 0;
+				}
+				cprev = cnow;
+			}
+			/* NOTREACHED */
+
+		/* 
+		 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
+		 * Return: write counters to the user passed counter struct
+		 * NB: both 1->0 and 0->1 transitions are counted except for
+		 *     RI where only 0->1 is counted.
+		 */
+		case TIOCGICOUNT:
+			cli();
+			cnow = info->icount;
+			sti();
+			p_cuser = (struct serial_icounter_struct *) arg;
+			if ((error = put_user(cnow.cts, &p_cuser->cts)))
+				return error;
+			if ((error = put_user(cnow.dsr, &p_cuser->dsr)))
+				return error;
+			if ((error = put_user(cnow.rng, &p_cuser->rng)))
+				return error;
+			if ((error = put_user(cnow.dcd, &p_cuser->dcd)))
+				return error;
+
+			return 0;
+
+		default:
+			return -ENOIOCTLCMD;
+		}
+	return 0;
+}
+
+static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
+{
+	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
+
+	if (   (tty->termios->c_cflag == old_termios->c_cflag)
+	    && (   RELEVANT_IFLAG(tty->termios->c_iflag) 
+		== RELEVANT_IFLAG(old_termios->c_iflag)))
+	  return;
+
+	change_speed(info);
+
+	if ((old_termios->c_cflag & CRTSCTS) &&
+	    !(tty->termios->c_cflag & CRTSCTS)) {
+		tty->hw_stopped = 0;
+		rs_start(tty);
+	}
+
+#if 0
+	/*
+	 * No need to wake up processes in open wait, since they
+	 * sample the CLOCAL flag once, and don't recheck it.
+	 * XXX  It's not clear whether the current behavior is correct
+	 * or not.  Hence, this may change.....
+	 */
+	if (!(old_termios->c_cflag & CLOCAL) &&
+	    (tty->termios->c_cflag & CLOCAL))
+		wake_up_interruptible(&info->open_wait);
+#endif
+}
+
+/*
+ * ------------------------------------------------------------
+ * 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
+ * async 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 esp_struct * info = (struct esp_struct *)tty->driver_data;
+	unsigned long flags;
+	unsigned long timeout;
+
+	if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
+		return;
+	
+	save_flags(flags); cli();
+	
+	if (tty_hung_up_p(filp)) {
+		DBG_CNT("before DEC-hung");
+		MOD_DEC_USE_COUNT;
+		restore_flags(flags);
+		return;
+	}
+	
+#ifdef SERIAL_DEBUG_OPEN
+	printk("rs_close ttys%d, count = %d\n", 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("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("rs_close: bad serial port count for ttys%d: %d\n",
+		       info->line, info->count);
+		info->count = 0;
+	}
+	if (info->count) {
+		DBG_CNT("before DEC-2");
+		MOD_DEC_USE_COUNT;
+		restore_flags(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;
+	if (info->flags & ASYNC_CALLOUT_ACTIVE)
+		info->callout_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 receive line status interrupts, and tell the
+	 * interrupt driver to stop checking the data ready bit in the
+	 * line status register.
+	 */
+	/* info->IER &= ~UART_IER_RLSI; */
+	info->IER &= ~UART_IER_RDI;
+	info->read_status_mask &= ~UART_LSR_DR;
+	if (info->flags & ASYNC_INITIALIZED) {
+		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
+		serial_out(info, UART_ESI_CMD2, info->IER);
+
+		/* disable receive timeout */
+		serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
+		serial_out(info, UART_ESI_CMD2, 0x00);
+
+		/*
+		 * Before we drop DTR, make sure the UART transmitter
+		 * has completely drained; this is especially
+		 * important if there is a transmit FIFO!
+		 */
+		timeout = jiffies+HZ;
+		serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
+		serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
+		while ((serial_in(info, UART_ESI_STAT1) != 0x03) ||
+			(serial_in(info, UART_ESI_STAT2) != 0xff)) {
+			current->state = TASK_INTERRUPTIBLE;
+			current->timeout = jiffies + info->timeout;
+			schedule();
+			if (jiffies > timeout)
+				break;
+			serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
+			serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
+		}
+	}
+	shutdown(info);
+	if (tty->driver.flush_buffer)
+		tty->driver.flush_buffer(tty);
+	if (tty->ldisc.flush_buffer)
+		tty->ldisc.flush_buffer(tty);
+	tty->closing = 0;
+	info->event = 0;
+	info->tty = 0;
+
+	if (info->tty_buf) {
+		while (info->tty_buf->tqueue.sync) {
+			current->state = TASK_INTERRUPTIBLE;
+			current->timeout = jiffies + HZ / 10;
+			schedule();
+		}
+
+		kfree(info->tty_buf);
+		info->tty_buf = 0;
+	}
+			
+	if (info->blocked_open) {
+		if (info->close_delay) {
+			current->state = TASK_INTERRUPTIBLE;
+			current->timeout = jiffies + info->close_delay;
+			schedule();
+		}
+		wake_up_interruptible(&info->open_wait);
+	}
+	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE|
+			 ASYNC_CLOSING);
+	wake_up_interruptible(&info->close_wait);
+	MOD_DEC_USE_COUNT;
+	restore_flags(flags);
+}
+
+/*
+ * esp_hangup() --- called by tty_hangup() when a hangup is signaled.
+ */
+static void esp_hangup(struct tty_struct *tty)
+{
+	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
+	
+	if (serial_paranoia_check(info, tty->device, "esp_hangup"))
+		return;
+	
+	rs_flush_buffer(tty);
+	shutdown(info);
+	info->event = 0;
+	info->count = 0;
+	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE);
+	info->tty = 0;
+	wake_up_interruptible(&info->open_wait);
+}
+
+/*
+ * ------------------------------------------------------------
+ * esp_open() and friends
+ * ------------------------------------------------------------
+ */
+static int block_til_ready(struct tty_struct *tty, struct file * filp,
+			   struct esp_struct *info)
+{
+	struct wait_queue wait = { current, NULL };
+	int		retval;
+	int		do_clocal = 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)) {
+		if (info->flags & ASYNC_CLOSING)
+			interruptible_sleep_on(&info->close_wait);
+#ifdef SERIAL_DO_RESTART
+		if (info->flags & ASYNC_HUP_NOTIFY)
+			return -EAGAIN;
+		else
+			return -ERESTARTSYS;
+#else
+		return -EAGAIN;
+#endif
+	}
+
+	/*
+	 * If this is a callout device, then just make sure the normal
+	 * device isn't being used.
+	 */
+	if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
+		if (info->flags & ASYNC_NORMAL_ACTIVE)
+			return -EBUSY;
+		if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
+		    (info->flags & ASYNC_SESSION_LOCKOUT) &&
+		    (info->session != current->session))
+		    return -EBUSY;
+		if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
+		    (info->flags & ASYNC_PGRP_LOCKOUT) &&
+		    (info->pgrp != current->pgrp))
+		    return -EBUSY;
+		info->flags |= ASYNC_CALLOUT_ACTIVE;
+		return 0;
+	}
+	
+	/*
+	 * 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))) {
+		if (info->flags & ASYNC_CALLOUT_ACTIVE)
+			return -EBUSY;
+		info->flags |= ASYNC_NORMAL_ACTIVE;
+		return 0;
+	}
+
+	if (info->flags & ASYNC_CALLOUT_ACTIVE) {
+		if (info->normal_termios.c_cflag & CLOCAL)
+			do_clocal = 1;
+	} else {
+		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
+	cli();
+	if (!tty_hung_up_p(filp)) 
+		info->count--;
+	sti();
+	info->blocked_open++;
+	while (1) {
+		cli();
+		if (!(info->flags & ASYNC_CALLOUT_ACTIVE)) {
+			unsigned int scratch;
+
+			serial_out(info, UART_ESI_CMD1, ESI_READ_UART);
+			serial_out(info, UART_ESI_CMD2, UART_MCR);
+			scratch = serial_in(info, UART_ESI_STAT1);
+			serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+			serial_out(info, UART_ESI_CMD2, UART_MCR);
+			serial_out(info, UART_ESI_CMD2,
+				scratch | UART_MCR_DTR | UART_MCR_RTS);
+		}
+		sti();
+		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;
+		}
+
+		serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
+		if (serial_in(info, UART_ESI_STAT2) & UART_MSR_DCD)
+			do_clocal = 1;
+
+		if (!(info->flags & ASYNC_CALLOUT_ACTIVE) &&
+		    !(info->flags & ASYNC_CLOSING) &&
+		    (do_clocal))
+			break;
+		if (current->signal & ~current->blocked) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+#ifdef SERIAL_DEBUG_OPEN
+		printk("block_til_ready blocking: ttys%d, count = %d\n",
+		       info->line, info->count);
+#endif
+		schedule();
+	}
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&info->open_wait, &wait);
+	if (!tty_hung_up_p(filp))
+		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;
+}	
+
+/*
+ * This routine is called whenever a serial port is opened.  It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain.   It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int esp_open(struct tty_struct *tty, struct file * filp)
+{
+	struct esp_struct	*info;
+	int 			i, retval, line;
+	unsigned long		page;
+
+	line = MINOR(tty->device) - tty->driver.minor_start;
+	if ((line < 0) || (line >= NR_PORTS))
+		return -ENODEV;
+
+	/* check whether or not the port is on the closed chain */
+
+	info = IRQ_ports[0];
+
+	while (info && (info->line != line))
+		info = info->next_port;
+
+	/* if the port is not on the closed chain, look for it on the */
+	/* open chain */
+
+	if (!info) {
+		i = 1;
+
+		while ((i < 16) && !IRQ_ports[i])
+			i++;
+
+		if (i < 16) {
+			info = IRQ_ports[i];
+
+			do {
+				if (info->line == line)
+					break;
+				info = info->next_port;
+			} while (info != IRQ_ports[i]);
+		}
+	}
+
+	if (!info || (info->line != line) || 
+		serial_paranoia_check(info, tty->device, "esp_open"))
+		return -ENODEV;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("esp_open %s%d, count = %d\n", tty->driver.name, info->line,
+	       info->count);
+#endif
+	MOD_INC_USE_COUNT;
+	info->count++;
+	tty->driver_data = info;
+	info->tty = tty;
+
+	if (!tmp_buf) {
+		page = get_free_page(GFP_KERNEL);
+		if (!page)
+			return -ENOMEM;
+		if (tmp_buf)
+			free_page(page);
+		else
+			tmp_buf = (unsigned char *) page;
+	}
+	
+	/*
+	 * Start up serial port
+	 */
+	retval = startup(info);
+	if (retval)
+		return retval;
+
+	retval = block_til_ready(tty, filp, info);
+	if (retval) {
+#ifdef SERIAL_DEBUG_OPEN
+		printk("esp_open returning after block_til_ready with %d\n",
+		       retval);
+#endif
+		return retval;
+	}
+
+	if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) {
+		if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
+			*tty->termios = info->normal_termios;
+		else 
+			*tty->termios = info->callout_termios;
+		change_speed(info);
+	}
+
+	info->session = current->session;
+	info->pgrp = current->pgrp;
+
+#ifdef SERIAL_DEBUG_OPEN
+	printk("esp_open ttys%d successful...", info->line);
+#endif
+	return 0;
+}
+
+/*
+ * ---------------------------------------------------------------------
+ * esp_init() and friends
+ *
+ * esp_init() is called at boot-time to initialize the serial driver.
+ * ---------------------------------------------------------------------
+ */
+
+/*
+ * This routine prints out the appropriate serial driver version
+ * number, and identifies which options were configured into this
+ * driver.
+ */
+static void show_serial_version(void)
+{
+ 	printk(KERN_INFO "%s version %s (DMA %u, trigger level %u)\n",
+		serial_name, serial_version, dma, trigger);
+}
+
+/*
+ * This routine is called by esp_init() to initialize a specific serial
+ * port.  It determines what type of UART chip this serial port is
+ * using: 8250, 16450, 16550, 16550A.  The important question is
+ * whether or not this UART is a 16550A or not, since this will
+ * determine whether or not we can use its FIFO features or not.
+ */
+static void autoconfig(struct esp_struct * info)
+{
+	unsigned char status1, status2, scratch;
+	unsigned port = info->port;
+	unsigned long flags;
+
+	info->type = PORT_UNKNOWN;
+	
+	if (!port)
+		return;
+
+	save_flags(flags); cli();
+	
+	/*
+	 * Check for ESP card
+	 */
+	scratch = serial_in(info, UART_ESI_BASE);
+	if (scratch == 0xf3) {
+		serial_out(info, UART_ESI_CMD1, 0x00);
+		serial_out(info, UART_ESI_CMD1, 0x01);
+		status1 = serial_in(info, UART_ESI_STAT2);
+		status2 = status1 & 0x70;
+		if (status2 != 0x20) {
+			printk(" Old ESP found at %x\n",info->port);
+		} else {
+			serial_out(info, UART_ESI_CMD1, 0x02);
+			status1 = serial_in(info, UART_ESI_STAT1) & 0x03;
+			if (!(info->irq)) {
+				if ((status1 == 0x00) || (status1 == 0x02))
+					info->irq = 4;
+				else
+					info->irq = 3;
+			}
+			info->type = PORT_16550A;
+			request_region(port,8,"esp(auto)");
+
+			/* put card in enhanced mode */
+			/* this prevents access through */
+			/* the "old" IO ports */
+			esp_basic_init(info);
+
+			/* clear out MCR */
+			serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
+			serial_out(info, UART_ESI_CMD2, UART_MCR);
+			serial_out(info, UART_ESI_CMD2, 0x00);
+		}
+	}
+
+	restore_flags(flags);
+}
+
+/*
+ * The serial driver boot-time initialization code!
+ */
+int esp_init(void)
+{
+	int i, offset;
+	struct esp_struct * info;
+	int esp[] = {0x100,0x140,0x180,0x200,0x240,0x280,0x300,0x380};
+	
+	init_bh(ESP_BH, do_serial_bh);
+
+	for (i = 0; i < 16; i++) {
+		IRQ_ports[i] = 0;
+	}
+
+	if ((dma != 1) && (dma != 3))
+		dma = CONFIG_ESP_DMA_CHANNEL;
+
+	if ((trigger < 1) || (trigger > 1015))
+		trigger = 768;
+	
+	show_serial_version();
+
+	/* Initialize the tty_driver structure */
+	
+	memset(&esp_driver, 0, sizeof(struct tty_driver));
+	esp_driver.magic = TTY_DRIVER_MAGIC;
+	esp_driver.name = "ttyP";
+	esp_driver.major = ESP_IN_MAJOR;
+	esp_driver.minor_start = 0;
+	esp_driver.num = NR_PORTS;
+	esp_driver.type = TTY_DRIVER_TYPE_SERIAL;
+	esp_driver.subtype = SERIAL_TYPE_NORMAL;
+	esp_driver.init_termios = tty_std_termios;
+	esp_driver.init_termios.c_cflag =
+		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	esp_driver.flags = TTY_DRIVER_REAL_RAW;
+	esp_driver.refcount = &serial_refcount;
+	esp_driver.table = serial_table;
+	esp_driver.termios = serial_termios;
+	esp_driver.termios_locked = serial_termios_locked;
+
+	esp_driver.open = esp_open;
+	esp_driver.close = rs_close;
+	esp_driver.write = rs_write;
+	esp_driver.put_char = rs_put_char;
+	esp_driver.flush_chars = rs_flush_chars;
+	esp_driver.write_room = rs_write_room;
+	esp_driver.chars_in_buffer = rs_chars_in_buffer;
+	esp_driver.flush_buffer = rs_flush_buffer;
+	esp_driver.ioctl = rs_ioctl;
+	esp_driver.throttle = rs_throttle;
+	esp_driver.unthrottle = rs_unthrottle;
+	esp_driver.set_termios = rs_set_termios;
+	esp_driver.stop = rs_stop;
+	esp_driver.start = rs_start;
+	esp_driver.hangup = esp_hangup;
+
+	/*
+	 * The callout device is just like normal device except for
+	 * major number and the subtype code.
+	 */
+	esp_callout_driver = esp_driver;
+	esp_callout_driver.name = "cup";
+	esp_callout_driver.major = ESP_OUT_MAJOR;
+	esp_callout_driver.subtype = SERIAL_TYPE_CALLOUT;
+
+	if (tty_register_driver(&esp_driver))
+		panic("Couldn't register serial driver\n");
+	if (tty_register_driver(&esp_callout_driver))
+		panic("Couldn't register callout driver\n");
+	
+	info = (struct esp_struct *)kmalloc(sizeof(struct esp_struct),
+		GFP_KERNEL);
+	if (!info)
+		panic("Could not allocate memory for device information\n");
+	memset((void *)info, 0, sizeof(struct esp_struct));
+
+	i = 0;
+	offset = 0;
+
+	do {
+		info->port = esp[i] + offset;
+		info->baud_base = BASE_BAUD;
+		info->custom_divisor = (divisor[i] >> (offset / 2)) & 0xf;
+		info->flags = STD_COM_FLAGS;
+		if (info->custom_divisor)
+			info->flags |= ASYNC_SPD_CUST;
+		info->irq = irq[i];
+
+		info->magic = ESP_MAGIC;
+		info->line = (i * 8) + (offset / 8);
+		info->tty = 0;
+		info->type = PORT_UNKNOWN;
+		info->close_delay = 5*HZ/10;
+		info->closing_wait = 30*HZ;
+		info->tqueue.routine = do_softint;
+		info->tqueue.data = info;
+		info->tqueue_hangup.routine = do_serial_hangup;
+		info->tqueue_hangup.data = info;
+		info->callout_termios = esp_callout_driver.init_termios;
+		info->normal_termios = esp_driver.init_termios;
+
+		if (info->irq == 2)
+			info->irq = 9;
+
+		autoconfig(info);
+		if (info->type == PORT_UNKNOWN) {
+			i++;
+			offset = 0;
+			continue;
+		}
+		if (IRQ_ports[0])
+			IRQ_ports[0]->prev_port = info;
+		info->next_port = IRQ_ports[0];
+		info->prev_port = 0;
+		IRQ_ports[0] = info;
+		printk(KERN_INFO "ttyP%d at 0x%04x (irq = %d) is an ESP ",
+			info->line, info->port, info->irq);
+		if (info->line % 8)
+			printk("secondary port\n");
+		else {
+			printk("primary port\n");
+			irq[i] = info->irq;
+		}
+
+		info = (struct esp_struct *)kmalloc(sizeof(struct esp_struct),
+			GFP_KERNEL);
+		if (!info)
+			panic("Could not allocate memory for device information\n");
+		memset((void *)info, 0, sizeof(struct esp_struct));
+
+		if (offset == 56) {
+			i++;
+			offset = 0;
+		} else {
+			offset += 8;
+		}
+	} while (i < NR_PRIMARY);
+
+	/* free the last port memory allocation */
+	kfree(info);
+
+	return 0;
+}
+
+#ifdef MODULE
+
+int init_module(void)
+{
+	return esp_init();
+}
+
+void cleanup_module(void) 
+{
+	unsigned long flags;
+	int e1, e2;
+	struct esp_struct *current_async, *temp_async;
+
+	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
+	save_flags(flags);
+	cli();
+	if ((e1 = tty_unregister_driver(&esp_driver)))
+		printk("SERIAL: failed to unregister serial driver (%d)\n",
+		       e1);
+	if ((e2 = tty_unregister_driver(&esp_callout_driver)))
+		printk("SERIAL: failed to unregister callout driver (%d)\n", 
+		       e2);
+	restore_flags(flags);
+
+	current_async = IRQ_ports[0];
+	while (current_async != 0) {
+		if (current_async->type != PORT_UNKNOWN)
+			release_region(current_async->port, 8);
+		current_async = current_async->next_port;
+	}
+
+	if (dma_buffer)
+		free_pages((unsigned int)dma_buffer,
+			__get_order(DMA_BUFFER_SZ));
+
+	if (tmp_buf)
+		free_page((unsigned long)tmp_buf);
+
+	/* free the port information */
+	current_async = IRQ_ports[0];
+	while (current_async != 0) {
+		temp_async = current_async->next_port;
+		kfree(current_async);
+		current_async = temp_async;
+	}
+}
+#endif /* MODULE */