/*
 * LIRC SIR driver, (C) 2000 Milan Pikula <www@fornax.sk>
 *
 * lirc_sir - Device driver for use with SIR (serial infra red)
 * mode of IrDA on many notebooks.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *
 * 2000/09/16 Frank Przybylski <mail@frankprzybylski.de> :
 *  added timeout and relaxed pulse detection, removed gap bug
 *
 * 2000/12/15 Christoph Bartelmus <lirc@bartelmus.de> :
 *   added support for Tekram Irmate 210 (sending does not work yet,
 *   kind of disappointing that nobody was able to implement that
 *   before),
 *   major clean-up
 *
 * 2001/02/27 Christoph Bartelmus <lirc@bartelmus.de> :
 *   added support for StrongARM SA1100 embedded microprocessor
 *   parts cut'n'pasted from sa1100_ir.c (C) 2000 Russell King
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/serial_reg.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <asm/system.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <linux/fcntl.h>
#ifdef LIRC_ON_SA1100
#include <asm/hardware.h>
#ifdef CONFIG_SA1100_COLLIE
#include <asm/arch/tc35143.h>
#include <asm/ucb1200.h>
#endif
#endif

#include <linux/timer.h>

#include <media/lirc.h>
#include <media/lirc_dev.h>

/* SECTION: Definitions */

/*** Tekram dongle ***/
#ifdef LIRC_SIR_TEKRAM
/* stolen from kernel source */
/* definitions for Tekram dongle */
#define TEKRAM_115200 0x00
#define TEKRAM_57600  0x01
#define TEKRAM_38400  0x02
#define TEKRAM_19200  0x03
#define TEKRAM_9600   0x04
#define TEKRAM_2400   0x08

#define TEKRAM_PW 0x10 /* Pulse select bit */

/* 10bit * 1s/115200bit in milliseconds = 87ms*/
#define TIME_CONST (10000000ul/115200ul)

#endif

#ifdef LIRC_SIR_ACTISYS_ACT200L
static void init_act200(void);
#elif defined(LIRC_SIR_ACTISYS_ACT220L)
static void init_act220(void);
#endif

/*** SA1100 ***/
#ifdef LIRC_ON_SA1100
struct sa1100_ser2_registers {
	/* HSSP control register */
	unsigned char hscr0;
	/* UART registers */
	unsigned char utcr0;
	unsigned char utcr1;
	unsigned char utcr2;
	unsigned char utcr3;
	unsigned char utcr4;
	unsigned char utdr;
	unsigned char utsr0;
	unsigned char utsr1;
} sr;

static int irq = IRQ_Ser2ICP;

#define LIRC_ON_SA1100_TRANSMITTER_LATENCY 0

/* pulse/space ratio of 50/50 */
static unsigned long pulse_width = (13-LIRC_ON_SA1100_TRANSMITTER_LATENCY);
/* 1000000/freq-pulse_width */
static unsigned long space_width = (13-LIRC_ON_SA1100_TRANSMITTER_LATENCY);
static unsigned int freq = 38000;      /* modulation frequency */
static unsigned int duty_cycle = 50;   /* duty cycle of 50% */

#endif

#define RBUF_LEN 1024
#define WBUF_LEN 1024

#define LIRC_DRIVER_NAME "lirc_sir"

#define PULSE '['

#ifndef LIRC_SIR_TEKRAM
/* 9bit * 1s/115200bit in milli seconds = 78.125ms*/
#define TIME_CONST (9000000ul/115200ul)
#endif


/* timeout for sequences in jiffies (=5/100s), must be longer than TIME_CONST */
#define SIR_TIMEOUT	(HZ*5/100)

#ifndef LIRC_ON_SA1100
#ifndef LIRC_IRQ
#define LIRC_IRQ 4
#endif
#ifndef LIRC_PORT
/* for external dongles, default to com1 */
#if defined(LIRC_SIR_ACTISYS_ACT200L)         || \
	    defined(LIRC_SIR_ACTISYS_ACT220L) || \
	    defined(LIRC_SIR_TEKRAM)
#define LIRC_PORT 0x3f8
#else
/* onboard sir ports are typically com3 */
#define LIRC_PORT 0x3e8
#endif
#endif

static int io = LIRC_PORT;
static int irq = LIRC_IRQ;
static int threshold = 3;
#endif

static DEFINE_SPINLOCK(timer_lock);
static struct timer_list timerlist;
/* time of last signal change detected */
static struct timeval last_tv = {0, 0};
/* time of last UART data ready interrupt */
static struct timeval last_intr_tv = {0, 0};
static int last_value;

static DECLARE_WAIT_QUEUE_HEAD(lirc_read_queue);

static DEFINE_SPINLOCK(hardware_lock);

static int rx_buf[RBUF_LEN];
static unsigned int rx_tail, rx_head;

static int debug;
#define dprintk(fmt, args...)						\
	do {								\
		if (debug)						\
			printk(KERN_DEBUG LIRC_DRIVER_NAME ": "		\
				fmt, ## args);				\
	} while (0)

/* SECTION: Prototypes */

/* Communication with user-space */
static unsigned int lirc_poll(struct file *file, poll_table *wait);
static ssize_t lirc_read(struct file *file, char *buf, size_t count,
		loff_t *ppos);
static ssize_t lirc_write(struct file *file, const char *buf, size_t n,
		loff_t *pos);
static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
static void add_read_queue(int flag, unsigned long val);
static int init_chrdev(void);
static void drop_chrdev(void);
/* Hardware */
static irqreturn_t sir_interrupt(int irq, void *dev_id);
static void send_space(unsigned long len);
static void send_pulse(unsigned long len);
static int init_hardware(void);
static void drop_hardware(void);
/* Initialisation */
static int init_port(void);
static void drop_port(void);

#ifdef LIRC_ON_SA1100
static void on(void)
{
	PPSR |= PPC_TXD2;
}

static void off(void)
{
	PPSR &= ~PPC_TXD2;
}
#else
static inline unsigned int sinp(int offset)
{
	return inb(io + offset);
}

static inline void soutp(int offset, int value)
{
	outb(value, io + offset);
}
#endif

#ifndef MAX_UDELAY_MS
#define MAX_UDELAY_US 5000
#else
#define MAX_UDELAY_US (MAX_UDELAY_MS*1000)
#endif

static void safe_udelay(unsigned long usecs)
{
	while (usecs > MAX_UDELAY_US) {
		udelay(MAX_UDELAY_US);
		usecs -= MAX_UDELAY_US;
	}
	udelay(usecs);
}

/* SECTION: Communication with user-space */

static unsigned int lirc_poll(struct file *file, poll_table *wait)
{
	poll_wait(file, &lirc_read_queue, wait);
	if (rx_head != rx_tail)
		return POLLIN | POLLRDNORM;
	return 0;
}

static ssize_t lirc_read(struct file *file, char *buf, size_t count,
		loff_t *ppos)
{
	int n = 0;
	int retval = 0;
	DECLARE_WAITQUEUE(wait, current);

	if (count % sizeof(int))
		return -EINVAL;

	add_wait_queue(&lirc_read_queue, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	while (n < count) {
		if (rx_head != rx_tail) {
			if (copy_to_user((void *) buf + n,
					(void *) (rx_buf + rx_head),
					sizeof(int))) {
				retval = -EFAULT;
				break;
			}
			rx_head = (rx_head + 1) & (RBUF_LEN - 1);
			n += sizeof(int);
		} else {
			if (file->f_flags & O_NONBLOCK) {
				retval = -EAGAIN;
				break;
			}
			if (signal_pending(current)) {
				retval = -ERESTARTSYS;
				break;
			}
			schedule();
			set_current_state(TASK_INTERRUPTIBLE);
		}
	}
	remove_wait_queue(&lirc_read_queue, &wait);
	set_current_state(TASK_RUNNING);
	return n ? n : retval;
}
static ssize_t lirc_write(struct file *file, const char *buf, size_t n,
				loff_t *pos)
{
	unsigned long flags;
	int i, count;
	int *tx_buf;

	count = n / sizeof(int);
	if (n % sizeof(int) || count % 2 == 0)
		return -EINVAL;
	tx_buf = memdup_user(buf, n);
	if (IS_ERR(tx_buf))
		return PTR_ERR(tx_buf);
	i = 0;
#ifdef LIRC_ON_SA1100
	/* disable receiver */
	Ser2UTCR3 = 0;
#endif
	local_irq_save(flags);
	while (1) {
		if (i >= count)
			break;
		if (tx_buf[i])
			send_pulse(tx_buf[i]);
		i++;
		if (i >= count)
			break;
		if (tx_buf[i])
			send_space(tx_buf[i]);
		i++;
	}
	local_irq_restore(flags);
#ifdef LIRC_ON_SA1100
	off();
	udelay(1000); /* wait 1ms for IR diode to recover */
	Ser2UTCR3 = 0;
	/* clear status register to prevent unwanted interrupts */
	Ser2UTSR0 &= (UTSR0_RID | UTSR0_RBB | UTSR0_REB);
	/* enable receiver */
	Ser2UTCR3 = UTCR3_RXE|UTCR3_RIE;
#endif
	kfree(tx_buf);
	return count;
}

static long lirc_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
{
	int retval = 0;
	__u32 value = 0;
#ifdef LIRC_ON_SA1100

	if (cmd == LIRC_GET_FEATURES)
		value = LIRC_CAN_SEND_PULSE |
			LIRC_CAN_SET_SEND_DUTY_CYCLE |
			LIRC_CAN_SET_SEND_CARRIER |
			LIRC_CAN_REC_MODE2;
	else if (cmd == LIRC_GET_SEND_MODE)
		value = LIRC_MODE_PULSE;
	else if (cmd == LIRC_GET_REC_MODE)
		value = LIRC_MODE_MODE2;
#else
	if (cmd == LIRC_GET_FEATURES)
		value = LIRC_CAN_SEND_PULSE | LIRC_CAN_REC_MODE2;
	else if (cmd == LIRC_GET_SEND_MODE)
		value = LIRC_MODE_PULSE;
	else if (cmd == LIRC_GET_REC_MODE)
		value = LIRC_MODE_MODE2;
#endif

	switch (cmd) {
	case LIRC_GET_FEATURES:
	case LIRC_GET_SEND_MODE:
	case LIRC_GET_REC_MODE:
		retval = put_user(value, (__u32 *) arg);
		break;

	case LIRC_SET_SEND_MODE:
	case LIRC_SET_REC_MODE:
		retval = get_user(value, (__u32 *) arg);
		break;
#ifdef LIRC_ON_SA1100
	case LIRC_SET_SEND_DUTY_CYCLE:
		retval = get_user(value, (__u32 *) arg);
		if (retval)
			return retval;
		if (value <= 0 || value > 100)
			return -EINVAL;
		/* (value/100)*(1000000/freq) */
		duty_cycle = value;
		pulse_width = (unsigned long) duty_cycle*10000/freq;
		space_width = (unsigned long) 1000000L/freq-pulse_width;
		if (pulse_width >= LIRC_ON_SA1100_TRANSMITTER_LATENCY)
			pulse_width -= LIRC_ON_SA1100_TRANSMITTER_LATENCY;
		if (space_width >= LIRC_ON_SA1100_TRANSMITTER_LATENCY)
			space_width -= LIRC_ON_SA1100_TRANSMITTER_LATENCY;
		break;
	case LIRC_SET_SEND_CARRIER:
		retval = get_user(value, (__u32 *) arg);
		if (retval)
			return retval;
		if (value > 500000 || value < 20000)
			return -EINVAL;
		freq = value;
		pulse_width = (unsigned long) duty_cycle*10000/freq;
		space_width = (unsigned long) 1000000L/freq-pulse_width;
		if (pulse_width >= LIRC_ON_SA1100_TRANSMITTER_LATENCY)
			pulse_width -= LIRC_ON_SA1100_TRANSMITTER_LATENCY;
		if (space_width >= LIRC_ON_SA1100_TRANSMITTER_LATENCY)
			space_width -= LIRC_ON_SA1100_TRANSMITTER_LATENCY;
		break;
#endif
	default:
		retval = -ENOIOCTLCMD;

	}

	if (retval)
		return retval;
	if (cmd == LIRC_SET_REC_MODE) {
		if (value != LIRC_MODE_MODE2)
			retval = -ENOSYS;
	} else if (cmd == LIRC_SET_SEND_MODE) {
		if (value != LIRC_MODE_PULSE)
			retval = -ENOSYS;
	}

	return retval;
}

static void add_read_queue(int flag, unsigned long val)
{
	unsigned int new_rx_tail;
	int newval;

	dprintk("add flag %d with val %lu\n", flag, val);

	newval = val & PULSE_MASK;

	/*
	 * statistically, pulses are ~TIME_CONST/2 too long. we could
	 * maybe make this more exact, but this is good enough
	 */
	if (flag) {
		/* pulse */
		if (newval > TIME_CONST/2)
			newval -= TIME_CONST/2;
		else /* should not ever happen */
			newval = 1;
		newval |= PULSE_BIT;
	} else {
		newval += TIME_CONST/2;
	}
	new_rx_tail = (rx_tail + 1) & (RBUF_LEN - 1);
	if (new_rx_tail == rx_head) {
		dprintk("Buffer overrun.\n");
		return;
	}
	rx_buf[rx_tail] = newval;
	rx_tail = new_rx_tail;
	wake_up_interruptible(&lirc_read_queue);
}

static const struct file_operations lirc_fops = {
	.owner		= THIS_MODULE,
	.read		= lirc_read,
	.write		= lirc_write,
	.poll		= lirc_poll,
	.unlocked_ioctl	= lirc_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= lirc_ioctl,
#endif
	.open		= lirc_dev_fop_open,
	.release	= lirc_dev_fop_close,
	.llseek		= no_llseek,
};

static int set_use_inc(void *data)
{
	return 0;
}

static void set_use_dec(void *data)
{
}

static struct lirc_driver driver = {
	.name		= LIRC_DRIVER_NAME,
	.minor		= -1,
	.code_length	= 1,
	.sample_rate	= 0,
	.data		= NULL,
	.add_to_buf	= NULL,
	.set_use_inc	= set_use_inc,
	.set_use_dec	= set_use_dec,
	.fops		= &lirc_fops,
	.dev		= NULL,
	.owner		= THIS_MODULE,
};


static int init_chrdev(void)
{
	driver.minor = lirc_register_driver(&driver);
	if (driver.minor < 0) {
		printk(KERN_ERR LIRC_DRIVER_NAME ": init_chrdev() failed.\n");
		return -EIO;
	}
	return 0;
}

static void drop_chrdev(void)
{
	lirc_unregister_driver(driver.minor);
}

/* SECTION: Hardware */
static long delta(struct timeval *tv1, struct timeval *tv2)
{
	unsigned long deltv;

	deltv = tv2->tv_sec - tv1->tv_sec;
	if (deltv > 15)
		deltv = 0xFFFFFF;
	else
		deltv = deltv*1000000 +
			tv2->tv_usec -
			tv1->tv_usec;
	return deltv;
}

static void sir_timeout(unsigned long data)
{
	/*
	 * if last received signal was a pulse, but receiving stopped
	 * within the 9 bit frame, we need to finish this pulse and
	 * simulate a signal change to from pulse to space. Otherwise
	 * upper layers will receive two sequences next time.
	 */

	unsigned long flags;
	unsigned long pulse_end;

	/* avoid interference with interrupt */
	spin_lock_irqsave(&timer_lock, flags);
	if (last_value) {
#ifndef LIRC_ON_SA1100
		/* clear unread bits in UART and restart */
		outb(UART_FCR_CLEAR_RCVR, io + UART_FCR);
#endif
		/* determine 'virtual' pulse end: */
		pulse_end = delta(&last_tv, &last_intr_tv);
		dprintk("timeout add %d for %lu usec\n", last_value, pulse_end);
		add_read_queue(last_value, pulse_end);
		last_value = 0;
		last_tv = last_intr_tv;
	}
	spin_unlock_irqrestore(&timer_lock, flags);
}

static irqreturn_t sir_interrupt(int irq, void *dev_id)
{
	unsigned char data;
	struct timeval curr_tv;
	static unsigned long deltv;
#ifdef LIRC_ON_SA1100
	int status;
	static int n;

	status = Ser2UTSR0;
	/*
	 * Deal with any receive errors first.  The bytes in error may be
	 * the only bytes in the receive FIFO, so we do this first.
	 */
	while (status & UTSR0_EIF) {
		int bstat;

		if (debug) {
			dprintk("EIF\n");
			bstat = Ser2UTSR1;

			if (bstat & UTSR1_FRE)
				dprintk("frame error\n");
			if (bstat & UTSR1_ROR)
				dprintk("receive fifo overrun\n");
			if (bstat & UTSR1_PRE)
				dprintk("parity error\n");
		}

		bstat = Ser2UTDR;
		n++;
		status = Ser2UTSR0;
	}

	if (status & (UTSR0_RFS | UTSR0_RID)) {
		do_gettimeofday(&curr_tv);
		deltv = delta(&last_tv, &curr_tv);
		do {
			data = Ser2UTDR;
			dprintk("%d data: %u\n", n, (unsigned int) data);
			n++;
		} while (status & UTSR0_RID && /* do not empty fifo in order to
						* get UTSR0_RID in any case */
		      Ser2UTSR1 & UTSR1_RNE); /* data ready */

		if (status&UTSR0_RID) {
			add_read_queue(0 , deltv - n * TIME_CONST); /*space*/
			add_read_queue(1, n * TIME_CONST); /*pulse*/
			n = 0;
			last_tv = curr_tv;
		}
	}

	if (status & UTSR0_TFS)
		printk(KERN_ERR "transmit fifo not full, shouldn't happen\n");

	/* We must clear certain bits. */
	status &= (UTSR0_RID | UTSR0_RBB | UTSR0_REB);
	if (status)
		Ser2UTSR0 = status;
#else
	unsigned long deltintrtv;
	unsigned long flags;
	int iir, lsr;

	while ((iir = inb(io + UART_IIR) & UART_IIR_ID)) {
		switch (iir&UART_IIR_ID) { /* FIXME toto treba preriedit */
		case UART_IIR_MSI:
			(void) inb(io + UART_MSR);
			break;
		case UART_IIR_RLSI:
			(void) inb(io + UART_LSR);
			break;
		case UART_IIR_THRI:
#if 0
			if (lsr & UART_LSR_THRE) /* FIFO is empty */
				outb(data, io + UART_TX)
#endif
			break;
		case UART_IIR_RDI:
			/* avoid interference with timer */
			spin_lock_irqsave(&timer_lock, flags);
			do {
				del_timer(&timerlist);
				data = inb(io + UART_RX);
				do_gettimeofday(&curr_tv);
				deltv = delta(&last_tv, &curr_tv);
				deltintrtv = delta(&last_intr_tv, &curr_tv);
				dprintk("t %lu, d %d\n", deltintrtv, (int)data);
				/*
				 * if nothing came in last X cycles,
				 * it was gap
				 */
				if (deltintrtv > TIME_CONST * threshold) {
					if (last_value) {
						dprintk("GAP\n");
						/* simulate signal change */
						add_read_queue(last_value,
							       deltv -
							       deltintrtv);
						last_value = 0;
						last_tv.tv_sec =
							last_intr_tv.tv_sec;
						last_tv.tv_usec =
							last_intr_tv.tv_usec;
						deltv = deltintrtv;
					}
				}
				data = 1;
				if (data ^ last_value) {
					/*
					 * deltintrtv > 2*TIME_CONST, remember?
					 * the other case is timeout
					 */
					add_read_queue(last_value,
						       deltv-TIME_CONST);
					last_value = data;
					last_tv = curr_tv;
					if (last_tv.tv_usec >= TIME_CONST) {
						last_tv.tv_usec -= TIME_CONST;
					} else {
						last_tv.tv_sec--;
						last_tv.tv_usec += 1000000 -
							TIME_CONST;
					}
				}
				last_intr_tv = curr_tv;
				if (data) {
					/*
					 * start timer for end of
					 * sequence detection
					 */
					timerlist.expires = jiffies +
								SIR_TIMEOUT;
					add_timer(&timerlist);
				}

				lsr = inb(io + UART_LSR);
			} while (lsr & UART_LSR_DR); /* data ready */
			spin_unlock_irqrestore(&timer_lock, flags);
			break;
		default:
			break;
		}
	}
#endif
	return IRQ_RETVAL(IRQ_HANDLED);
}

#ifdef LIRC_ON_SA1100
static void send_pulse(unsigned long length)
{
	unsigned long k, delay;
	int flag;

	if (length == 0)
		return;
	/*
	 * this won't give us the carrier frequency we really want
	 * due to integer arithmetic, but we can accept this inaccuracy
	 */

	for (k = flag = 0; k < length; k += delay, flag = !flag) {
		if (flag) {
			off();
			delay = space_width;
		} else {
			on();
			delay = pulse_width;
		}
		safe_udelay(delay);
	}
	off();
}

static void send_space(unsigned long length)
{
	if (length == 0)
		return;
	off();
	safe_udelay(length);
}
#else
static void send_space(unsigned long len)
{
	safe_udelay(len);
}

static void send_pulse(unsigned long len)
{
	long bytes_out = len / TIME_CONST;
	long time_left;

	time_left = (long)len - (long)bytes_out * (long)TIME_CONST;
	if (bytes_out == 0) {
		bytes_out++;
		time_left = 0;
	}
	while (bytes_out--) {
		outb(PULSE, io + UART_TX);
		/* FIXME treba seriozne cakanie z char/serial.c */
		while (!(inb(io + UART_LSR) & UART_LSR_THRE))
			;
	}
#if 0
	if (time_left > 0)
		safe_udelay(time_left);
#endif
}
#endif

#ifdef CONFIG_SA1100_COLLIE
static int sa1100_irda_set_power_collie(int state)
{
	if (state) {
		/*
		 *  0 - off
		 *  1 - short range, lowest power
		 *  2 - medium range, medium power
		 *  3 - maximum range, high power
		 */
		ucb1200_set_io_direction(TC35143_GPIO_IR_ON,
					 TC35143_IODIR_OUTPUT);
		ucb1200_set_io(TC35143_GPIO_IR_ON, TC35143_IODAT_LOW);
		udelay(100);
	} else {
		/* OFF */
		ucb1200_set_io_direction(TC35143_GPIO_IR_ON,
					 TC35143_IODIR_OUTPUT);
		ucb1200_set_io(TC35143_GPIO_IR_ON, TC35143_IODAT_HIGH);
	}
	return 0;
}
#endif

static int init_hardware(void)
{
	unsigned long flags;

	spin_lock_irqsave(&hardware_lock, flags);
	/* reset UART */
#ifdef LIRC_ON_SA1100
#ifdef CONFIG_SA1100_BITSY
	if (machine_is_bitsy()) {
		printk(KERN_INFO "Power on IR module\n");
		set_bitsy_egpio(EGPIO_BITSY_IR_ON);
	}
#endif
#ifdef CONFIG_SA1100_COLLIE
	sa1100_irda_set_power_collie(3);	/* power on */
#endif
	sr.hscr0 = Ser2HSCR0;

	sr.utcr0 = Ser2UTCR0;
	sr.utcr1 = Ser2UTCR1;
	sr.utcr2 = Ser2UTCR2;
	sr.utcr3 = Ser2UTCR3;
	sr.utcr4 = Ser2UTCR4;

	sr.utdr = Ser2UTDR;
	sr.utsr0 = Ser2UTSR0;
	sr.utsr1 = Ser2UTSR1;

	/* configure GPIO */
	/* output */
	PPDR |= PPC_TXD2;
	PSDR |= PPC_TXD2;
	/* set output to 0 */
	off();

	/* Enable HP-SIR modulation, and ensure that the port is disabled. */
	Ser2UTCR3 = 0;
	Ser2HSCR0 = sr.hscr0 & (~HSCR0_HSSP);

	/* clear status register to prevent unwanted interrupts */
	Ser2UTSR0 &= (UTSR0_RID | UTSR0_RBB | UTSR0_REB);

	/* 7N1 */
	Ser2UTCR0 = UTCR0_1StpBit|UTCR0_7BitData;
	/* 115200 */
	Ser2UTCR1 = 0;
	Ser2UTCR2 = 1;
	/* use HPSIR, 1.6 usec pulses */
	Ser2UTCR4 = UTCR4_HPSIR|UTCR4_Z1_6us;

	/* enable receiver, receive fifo interrupt */
	Ser2UTCR3 = UTCR3_RXE|UTCR3_RIE;

	/* clear status register to prevent unwanted interrupts */
	Ser2UTSR0 &= (UTSR0_RID | UTSR0_RBB | UTSR0_REB);

#elif defined(LIRC_SIR_TEKRAM)
	/* disable FIFO */
	soutp(UART_FCR,
	      UART_FCR_CLEAR_RCVR|
	      UART_FCR_CLEAR_XMIT|
	      UART_FCR_TRIGGER_1);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* First of all, disable all interrupts */
	soutp(UART_IER, sinp(UART_IER) &
	      (~(UART_IER_MSI|UART_IER_RLSI|UART_IER_THRI|UART_IER_RDI)));

	/* Set DLAB 1. */
	soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);

	/* Set divisor to 12 => 9600 Baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 12);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* power supply */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	safe_udelay(50*1000);

	/* -DTR low -> reset PIC */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_OUT2);
	udelay(1*1000);

	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	udelay(100);


	/* -RTS low -> send control byte */
	soutp(UART_MCR, UART_MCR_DTR|UART_MCR_OUT2);
	udelay(7);
	soutp(UART_TX, TEKRAM_115200|TEKRAM_PW);

	/* one byte takes ~1042 usec to transmit at 9600,8N1 */
	udelay(1500);

	/* back to normal operation */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	udelay(50);

	udelay(1500);

	/* read previous control byte */
	printk(KERN_INFO LIRC_DRIVER_NAME
	       ": 0x%02x\n", sinp(UART_RX));

	/* Set DLAB 1. */
	soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);

	/* Set divisor to 1 => 115200 Baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 1);

	/* Set DLAB 0, 8 Bit */
	soutp(UART_LCR, UART_LCR_WLEN8);
	/* enable interrupts */
	soutp(UART_IER, sinp(UART_IER)|UART_IER_RDI);
#else
	outb(0, io + UART_MCR);
	outb(0, io + UART_IER);
	/* init UART */
	/* set DLAB, speed = 115200 */
	outb(UART_LCR_DLAB | UART_LCR_WLEN7, io + UART_LCR);
	outb(1, io + UART_DLL); outb(0, io + UART_DLM);
	/* 7N1+start = 9 bits at 115200 ~ 3 bits at 44000 */
	outb(UART_LCR_WLEN7, io + UART_LCR);
	/* FIFO operation */
	outb(UART_FCR_ENABLE_FIFO, io + UART_FCR);
	/* interrupts */
	/* outb(UART_IER_RLSI|UART_IER_RDI|UART_IER_THRI, io + UART_IER); */
	outb(UART_IER_RDI, io + UART_IER);
	/* turn on UART */
	outb(UART_MCR_DTR|UART_MCR_RTS|UART_MCR_OUT2, io + UART_MCR);
#ifdef LIRC_SIR_ACTISYS_ACT200L
	init_act200();
#elif defined(LIRC_SIR_ACTISYS_ACT220L)
	init_act220();
#endif
#endif
	spin_unlock_irqrestore(&hardware_lock, flags);
	return 0;
}

static void drop_hardware(void)
{
	unsigned long flags;

	spin_lock_irqsave(&hardware_lock, flags);

#ifdef LIRC_ON_SA1100
	Ser2UTCR3 = 0;

	Ser2UTCR0 = sr.utcr0;
	Ser2UTCR1 = sr.utcr1;
	Ser2UTCR2 = sr.utcr2;
	Ser2UTCR4 = sr.utcr4;
	Ser2UTCR3 = sr.utcr3;

	Ser2HSCR0 = sr.hscr0;
#ifdef CONFIG_SA1100_BITSY
	if (machine_is_bitsy())
		clr_bitsy_egpio(EGPIO_BITSY_IR_ON);
#endif
#ifdef CONFIG_SA1100_COLLIE
	sa1100_irda_set_power_collie(0);	/* power off */
#endif
#else
	/* turn off interrupts */
	outb(0, io + UART_IER);
#endif
	spin_unlock_irqrestore(&hardware_lock, flags);
}

/* SECTION: Initialisation */

static int init_port(void)
{
	int retval;

	/* get I/O port access and IRQ line */
#ifndef LIRC_ON_SA1100
	if (request_region(io, 8, LIRC_DRIVER_NAME) == NULL) {
		printk(KERN_ERR LIRC_DRIVER_NAME
		       ": i/o port 0x%.4x already in use.\n", io);
		return -EBUSY;
	}
#endif
	retval = request_irq(irq, sir_interrupt, IRQF_DISABLED,
			     LIRC_DRIVER_NAME, NULL);
	if (retval < 0) {
#               ifndef LIRC_ON_SA1100
		release_region(io, 8);
#               endif
		printk(KERN_ERR LIRC_DRIVER_NAME
			": IRQ %d already in use.\n",
			irq);
		return retval;
	}
#ifndef LIRC_ON_SA1100
	printk(KERN_INFO LIRC_DRIVER_NAME
		": I/O port 0x%.4x, IRQ %d.\n",
		io, irq);
#endif

	init_timer(&timerlist);
	timerlist.function = sir_timeout;
	timerlist.data = 0xabadcafe;

	return 0;
}

static void drop_port(void)
{
	free_irq(irq, NULL);
	del_timer_sync(&timerlist);
#ifndef LIRC_ON_SA1100
	release_region(io, 8);
#endif
}

#ifdef LIRC_SIR_ACTISYS_ACT200L
/* Crystal/Cirrus CS8130 IR transceiver, used in Actisys Act200L dongle */
/* some code borrowed from Linux IRDA driver */

/* Register 0: Control register #1 */
#define ACT200L_REG0    0x00
#define ACT200L_TXEN    0x01 /* Enable transmitter */
#define ACT200L_RXEN    0x02 /* Enable receiver */
#define ACT200L_ECHO    0x08 /* Echo control chars */

/* Register 1: Control register #2 */
#define ACT200L_REG1    0x10
#define ACT200L_LODB    0x01 /* Load new baud rate count value */
#define ACT200L_WIDE    0x04 /* Expand the maximum allowable pulse */

/* Register 3: Transmit mode register #2 */
#define ACT200L_REG3    0x30
#define ACT200L_B0      0x01 /* DataBits, 0=6, 1=7, 2=8, 3=9(8P)  */
#define ACT200L_B1      0x02 /* DataBits, 0=6, 1=7, 2=8, 3=9(8P)  */
#define ACT200L_CHSY    0x04 /* StartBit Synced 0=bittime, 1=startbit */

/* Register 4: Output Power register */
#define ACT200L_REG4    0x40
#define ACT200L_OP0     0x01 /* Enable LED1C output */
#define ACT200L_OP1     0x02 /* Enable LED2C output */
#define ACT200L_BLKR    0x04

/* Register 5: Receive Mode register */
#define ACT200L_REG5    0x50
#define ACT200L_RWIDL   0x01 /* fixed 1.6us pulse mode */
    /*.. other various IRDA bit modes, and TV remote modes..*/

/* Register 6: Receive Sensitivity register #1 */
#define ACT200L_REG6    0x60
#define ACT200L_RS0     0x01 /* receive threshold bit 0 */
#define ACT200L_RS1     0x02 /* receive threshold bit 1 */

/* Register 7: Receive Sensitivity register #2 */
#define ACT200L_REG7    0x70
#define ACT200L_ENPOS   0x04 /* Ignore the falling edge */

/* Register 8,9: Baud Rate Divider register #1,#2 */
#define ACT200L_REG8    0x80
#define ACT200L_REG9    0x90

#define ACT200L_2400    0x5f
#define ACT200L_9600    0x17
#define ACT200L_19200   0x0b
#define ACT200L_38400   0x05
#define ACT200L_57600   0x03
#define ACT200L_115200  0x01

/* Register 13: Control register #3 */
#define ACT200L_REG13   0xd0
#define ACT200L_SHDW    0x01 /* Enable access to shadow registers */

/* Register 15: Status register */
#define ACT200L_REG15   0xf0

/* Register 21: Control register #4 */
#define ACT200L_REG21   0x50
#define ACT200L_EXCK    0x02 /* Disable clock output driver */
#define ACT200L_OSCL    0x04 /* oscillator in low power, medium accuracy mode */

static void init_act200(void)
{
	int i;
	__u8 control[] = {
		ACT200L_REG15,
		ACT200L_REG13 | ACT200L_SHDW,
		ACT200L_REG21 | ACT200L_EXCK | ACT200L_OSCL,
		ACT200L_REG13,
		ACT200L_REG7  | ACT200L_ENPOS,
		ACT200L_REG6  | ACT200L_RS0  | ACT200L_RS1,
		ACT200L_REG5  | ACT200L_RWIDL,
		ACT200L_REG4  | ACT200L_OP0  | ACT200L_OP1 | ACT200L_BLKR,
		ACT200L_REG3  | ACT200L_B0,
		ACT200L_REG0  | ACT200L_TXEN | ACT200L_RXEN,
		ACT200L_REG8 |  (ACT200L_115200       & 0x0f),
		ACT200L_REG9 | ((ACT200L_115200 >> 4) & 0x0f),
		ACT200L_REG1 | ACT200L_LODB | ACT200L_WIDE
	};

	/* Set DLAB 1. */
	soutp(UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN8);

	/* Set divisor to 12 => 9600 Baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 12);

	/* Set DLAB 0. */
	soutp(UART_LCR, UART_LCR_WLEN8);
	/* Set divisor to 12 => 9600 Baud */

	/* power supply */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	for (i = 0; i < 50; i++)
		safe_udelay(1000);

		/* Reset the dongle : set RTS low for 25 ms */
	soutp(UART_MCR, UART_MCR_DTR|UART_MCR_OUT2);
	for (i = 0; i < 25; i++)
		udelay(1000);

	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	udelay(100);

	/* Clear DTR and set RTS to enter command mode */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_OUT2);
	udelay(7);

	/* send out the control register settings for 115K 7N1 SIR operation */
	for (i = 0; i < sizeof(control); i++) {
		soutp(UART_TX, control[i]);
		/* one byte takes ~1042 usec to transmit at 9600,8N1 */
		udelay(1500);
	}

	/* back to normal operation */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	udelay(50);

	udelay(1500);
	soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);

	/* Set DLAB 1. */
	soutp(UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN7);

	/* Set divisor to 1 => 115200 Baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 1);

	/* Set DLAB 0. */
	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));

	/* Set DLAB 0, 7 Bit */
	soutp(UART_LCR, UART_LCR_WLEN7);

	/* enable interrupts */
	soutp(UART_IER, sinp(UART_IER)|UART_IER_RDI);
}
#endif

#ifdef LIRC_SIR_ACTISYS_ACT220L
/*
 * Derived from linux IrDA driver (net/irda/actisys.c)
 * Drop me a mail for any kind of comment: maxx@spaceboyz.net
 */

void init_act220(void)
{
	int i;

	/* DLAB 1 */
	soutp(UART_LCR, UART_LCR_DLAB|UART_LCR_WLEN7);

	/* 9600 baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 12);

	/* DLAB 0 */
	soutp(UART_LCR, UART_LCR_WLEN7);

	/* reset the dongle, set DTR low for 10us */
	soutp(UART_MCR, UART_MCR_RTS|UART_MCR_OUT2);
	udelay(10);

	/* back to normal (still 9600) */
	soutp(UART_MCR, UART_MCR_DTR|UART_MCR_RTS|UART_MCR_OUT2);

	/*
	 * send RTS pulses until we reach 115200
	 * i hope this is really the same for act220l/act220l+
	 */
	for (i = 0; i < 3; i++) {
		udelay(10);
		/* set RTS low for 10 us */
		soutp(UART_MCR, UART_MCR_DTR|UART_MCR_OUT2);
		udelay(10);
		/* set RTS high for 10 us */
		soutp(UART_MCR, UART_MCR_RTS|UART_MCR_DTR|UART_MCR_OUT2);
	}

	/* back to normal operation */
	udelay(1500); /* better safe than sorry ;) */

	/* Set DLAB 1. */
	soutp(UART_LCR, UART_LCR_DLAB | UART_LCR_WLEN7);

	/* Set divisor to 1 => 115200 Baud */
	soutp(UART_DLM, 0);
	soutp(UART_DLL, 1);

	/* Set DLAB 0, 7 Bit */
	/* The dongle doesn't seem to have any problems with operation at 7N1 */
	soutp(UART_LCR, UART_LCR_WLEN7);

	/* enable interrupts */
	soutp(UART_IER, UART_IER_RDI);
}
#endif

static int init_lirc_sir(void)
{
	int retval;

	init_waitqueue_head(&lirc_read_queue);
	retval = init_port();
	if (retval < 0)
		return retval;
	init_hardware();
	printk(KERN_INFO LIRC_DRIVER_NAME
		": Installed.\n");
	return 0;
}


static int __init lirc_sir_init(void)
{
	int retval;

	retval = init_chrdev();
	if (retval < 0)
		return retval;
	retval = init_lirc_sir();
	if (retval) {
		drop_chrdev();
		return retval;
	}
	return 0;
}

static void __exit lirc_sir_exit(void)
{
	drop_hardware();
	drop_chrdev();
	drop_port();
	printk(KERN_INFO LIRC_DRIVER_NAME ": Uninstalled.\n");
}

module_init(lirc_sir_init);
module_exit(lirc_sir_exit);

#ifdef LIRC_SIR_TEKRAM
MODULE_DESCRIPTION("Infrared receiver driver for Tekram Irmate 210");
MODULE_AUTHOR("Christoph Bartelmus");
#elif defined(LIRC_ON_SA1100)
MODULE_DESCRIPTION("LIRC driver for StrongARM SA1100 embedded microprocessor");
MODULE_AUTHOR("Christoph Bartelmus");
#elif defined(LIRC_SIR_ACTISYS_ACT200L)
MODULE_DESCRIPTION("LIRC driver for Actisys Act200L");
MODULE_AUTHOR("Karl Bongers");
#elif defined(LIRC_SIR_ACTISYS_ACT220L)
MODULE_DESCRIPTION("LIRC driver for Actisys Act220L(+)");
MODULE_AUTHOR("Jan Roemisch");
#else
MODULE_DESCRIPTION("Infrared receiver driver for SIR type serial ports");
MODULE_AUTHOR("Milan Pikula");
#endif
MODULE_LICENSE("GPL");

#ifdef LIRC_ON_SA1100
module_param(irq, int, S_IRUGO);
MODULE_PARM_DESC(irq, "Interrupt (16)");
#else
module_param(io, int, S_IRUGO);
MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");

module_param(irq, int, S_IRUGO);
MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");

module_param(threshold, int, S_IRUGO);
MODULE_PARM_DESC(threshold, "space detection threshold (3)");
#endif

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable debugging messages");