/*
 * 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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/io.h>
#include <asm/irq.h>
#include <linux/fcntl.h>
#include <linux/platform_device.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 bool 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 struct platform_device *lirc_sir_dev;

static int init_chrdev(void)
{
        driver.dev = &lirc_sir_dev->dev;
        driver.minor = lirc_register_driver(&driver);
        if (driver.minor < 0) {
                pr_err("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)
                pr_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;

        if (bytes_out == 0)
                bytes_out++;

        while (bytes_out--) {
                outb(PULSE, io + UART_TX);
                /* FIXME treba seriozne cakanie z char/serial.c */
                while (!(inb(io + UART_LSR) & UART_LSR_THRE))
                        ;
        }
}
#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_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 */
        pr_info("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_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) {
                pr_err("i/o port 0x%.4x already in use.\n", io);
                return -EBUSY;
        }
#endif
        retval = request_irq(irq, sir_interrupt, 0,
                             LIRC_DRIVER_NAME, NULL);
        if (retval < 0) {
#               ifndef LIRC_ON_SA1100
                release_region(io, 8);
#               endif
                pr_err("IRQ %d already in use.\n", irq);
                return retval;
        }
#ifndef LIRC_ON_SA1100
        pr_info("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();
        pr_info("Installed.\n");
        return 0;
}

static int lirc_sir_probe(struct platform_device *dev)
{
        return 0;
}

static int lirc_sir_remove(struct platform_device *dev)
{
        return 0;
}

static struct platform_driver lirc_sir_driver = {
        .probe          = lirc_sir_probe,
        .remove         = lirc_sir_remove,
        .driver         = {
                .name   = "lirc_sir",
                .owner  = THIS_MODULE,
        },
};

static int __init lirc_sir_init(void)
{
        int retval;

        retval = platform_driver_register(&lirc_sir_driver);
        if (retval) {
                pr_err("Platform driver register failed!\n");
                return -ENODEV;
        }

        lirc_sir_dev = platform_device_alloc("lirc_dev", 0);
        if (!lirc_sir_dev) {
                pr_err("Platform device alloc failed!\n");
                retval = -ENOMEM;
                goto pdev_alloc_fail;
        }

        retval = platform_device_add(lirc_sir_dev);
        if (retval) {
                pr_err("Platform device add failed!\n");
                retval = -ENODEV;
                goto pdev_add_fail;
        }

        retval = init_chrdev();
        if (retval < 0)
                goto fail;

        retval = init_lirc_sir();
        if (retval) {
                drop_chrdev();
                goto fail;
        }

        return 0;

fail:
        platform_device_del(lirc_sir_dev);
pdev_add_fail:
        platform_device_put(lirc_sir_dev);
pdev_alloc_fail:
        platform_driver_unregister(&lirc_sir_driver);
        return retval;
}

static void __exit lirc_sir_exit(void)
{
        drop_hardware();
        drop_chrdev();
        drop_port();
        platform_device_unregister(lirc_sir_dev);
        platform_driver_unregister(&lirc_sir_driver);
        pr_info("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");