ir-rx51.c

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/*
 *  Copyright (C) 2008 Nokia Corporation
 *
 *  Based on lirc_serial.c
 *
 *  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
 *
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/wait.h>

#include <plat/dmtimer.h>
#include <plat/clock.h>
#include <plat/omap-pm.h>

#include <media/lirc.h>
#include <media/lirc_dev.h>
#include <media/ir-rx51.h>

#define LIRC_RX51_DRIVER_FEATURES (LIRC_CAN_SET_SEND_DUTY_CYCLE |   \
                   LIRC_CAN_SET_SEND_CARRIER |      \
                   LIRC_CAN_SEND_PULSE)

#define DRIVER_NAME "lirc_rx51"

#define WBUF_LEN 256

#define TIMER_MAX_VALUE 0xffffffff

struct lirc_rx51 {
    struct omap_dm_timer *pwm_timer;
    struct omap_dm_timer *pulse_timer;
    struct device        *dev;
    struct lirc_rx51_platform_data *pdata;
    wait_queue_head_t     wqueue;

    unsigned long   fclk_khz;
    unsigned int    freq;       /* carrier frequency */
    unsigned int    duty_cycle; /* carrier duty cycle */
    unsigned int    irq_num;
    unsigned int    match;
    int     wbuf[WBUF_LEN];
    int     wbuf_index;
    unsigned long   device_is_open;
    int     pwm_timer_num;
};

static void lirc_rx51_on(struct lirc_rx51 *lirc_rx51)
{
    omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
                  OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE);
}

static void lirc_rx51_off(struct lirc_rx51 *lirc_rx51)
{
    omap_dm_timer_set_pwm(lirc_rx51->pwm_timer, 0, 1,
                  OMAP_TIMER_TRIGGER_NONE);
}

static int init_timing_params(struct lirc_rx51 *lirc_rx51)
{
    u32 load, match;

    load = -(lirc_rx51->fclk_khz * 1000 / lirc_rx51->freq);
    match = -(lirc_rx51->duty_cycle * -load / 100);
    omap_dm_timer_set_load(lirc_rx51->pwm_timer, 1, load);
    omap_dm_timer_set_match(lirc_rx51->pwm_timer, 1, match);
    omap_dm_timer_write_counter(lirc_rx51->pwm_timer, TIMER_MAX_VALUE - 2);
    omap_dm_timer_start(lirc_rx51->pwm_timer);
    omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
    omap_dm_timer_start(lirc_rx51->pulse_timer);

    lirc_rx51->match = 0;

    return 0;
}

#define tics_after(a, b) ((long)(b) - (long)(a) < 0)

static int pulse_timer_set_timeout(struct lirc_rx51 *lirc_rx51, int usec)
{
    int counter;

    BUG_ON(usec < 0);

    if (lirc_rx51->match == 0)
        counter = omap_dm_timer_read_counter(lirc_rx51->pulse_timer);
    else
        counter = lirc_rx51->match;

    counter += (u32)(lirc_rx51->fclk_khz * usec / (1000));
    omap_dm_timer_set_match(lirc_rx51->pulse_timer, 1, counter);
    omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer,
                     OMAP_TIMER_INT_MATCH);
    if (tics_after(omap_dm_timer_read_counter(lirc_rx51->pulse_timer),
               counter)) {
        return 1;
    }
    return 0;
}

static irqreturn_t lirc_rx51_interrupt_handler(int irq, void *ptr)
{
    unsigned int retval;
    struct lirc_rx51 *lirc_rx51 = ptr;

    retval = omap_dm_timer_read_status(lirc_rx51->pulse_timer);
    if (!retval)
        return IRQ_NONE;

    if (retval & ~OMAP_TIMER_INT_MATCH)
        dev_err_ratelimited(lirc_rx51->dev,
                ": Unexpected interrupt source: %x\n", retval);

    omap_dm_timer_write_status(lirc_rx51->pulse_timer,
                OMAP_TIMER_INT_MATCH    |
                OMAP_TIMER_INT_OVERFLOW |
                OMAP_TIMER_INT_CAPTURE);
    if (lirc_rx51->wbuf_index < 0) {
        dev_err_ratelimited(lirc_rx51->dev,
                ": BUG wbuf_index has value of %i\n",
                lirc_rx51->wbuf_index);
        goto end;
    }

    /*
     * If we happen to hit an odd latency spike, loop through the
     * pulses until we catch up.
     */
    do {
        if (lirc_rx51->wbuf_index >= WBUF_LEN)
            goto end;
        if (lirc_rx51->wbuf[lirc_rx51->wbuf_index] == -1)
            goto end;

        if (lirc_rx51->wbuf_index % 2)
            lirc_rx51_off(lirc_rx51);
        else
            lirc_rx51_on(lirc_rx51);

        retval = pulse_timer_set_timeout(lirc_rx51,
                    lirc_rx51->wbuf[lirc_rx51->wbuf_index]);
        lirc_rx51->wbuf_index++;

    } while (retval);

    return IRQ_HANDLED;
end:
    /* Stop TX here */
    lirc_rx51_off(lirc_rx51);
    lirc_rx51->wbuf_index = -1;
    omap_dm_timer_stop(lirc_rx51->pwm_timer);
    omap_dm_timer_stop(lirc_rx51->pulse_timer);
    omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
    wake_up_interruptible(&lirc_rx51->wqueue);

    return IRQ_HANDLED;
}

static int lirc_rx51_init_port(struct lirc_rx51 *lirc_rx51)
{
    struct clk *clk_fclk;
    int retval, pwm_timer = lirc_rx51->pwm_timer_num;

    lirc_rx51->pwm_timer = omap_dm_timer_request_specific(pwm_timer);
    if (lirc_rx51->pwm_timer == NULL) {
        dev_err(lirc_rx51->dev, ": Error requesting GPT%d timer\n",
            pwm_timer);
        return -EBUSY;
    }

    lirc_rx51->pulse_timer = omap_dm_timer_request();
    if (lirc_rx51->pulse_timer == NULL) {
        dev_err(lirc_rx51->dev, ": Error requesting pulse timer\n");
        retval = -EBUSY;
        goto err1;
    }

    omap_dm_timer_set_source(lirc_rx51->pwm_timer, OMAP_TIMER_SRC_SYS_CLK);
    omap_dm_timer_set_source(lirc_rx51->pulse_timer,
                OMAP_TIMER_SRC_SYS_CLK);

    omap_dm_timer_enable(lirc_rx51->pwm_timer);
    omap_dm_timer_enable(lirc_rx51->pulse_timer);

    lirc_rx51->irq_num = omap_dm_timer_get_irq(lirc_rx51->pulse_timer);
    retval = request_irq(lirc_rx51->irq_num, lirc_rx51_interrupt_handler,
                 IRQF_DISABLED | IRQF_SHARED,
                 "lirc_pulse_timer", lirc_rx51);
    if (retval) {
        dev_err(lirc_rx51->dev, ": Failed to request interrupt line\n");
        goto err2;
    }

    clk_fclk = omap_dm_timer_get_fclk(lirc_rx51->pwm_timer);
    lirc_rx51->fclk_khz = clk_fclk->rate / 1000;

    return 0;

err2:
    omap_dm_timer_free(lirc_rx51->pulse_timer);
err1:
    omap_dm_timer_free(lirc_rx51->pwm_timer);

    return retval;
}

static int lirc_rx51_free_port(struct lirc_rx51 *lirc_rx51)
{
    omap_dm_timer_set_int_enable(lirc_rx51->pulse_timer, 0);
    free_irq(lirc_rx51->irq_num, lirc_rx51);
    lirc_rx51_off(lirc_rx51);
    omap_dm_timer_disable(lirc_rx51->pwm_timer);
    omap_dm_timer_disable(lirc_rx51->pulse_timer);
    omap_dm_timer_free(lirc_rx51->pwm_timer);
    omap_dm_timer_free(lirc_rx51->pulse_timer);
    lirc_rx51->wbuf_index = -1;

    return 0;
}

static ssize_t lirc_rx51_write(struct file *file, const char *buf,
              size_t n, loff_t *ppos)
{
    int count, i;
    struct lirc_rx51 *lirc_rx51 = file->private_data;

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

    count = n / sizeof(int);
    if ((count > WBUF_LEN) || (count % 2 == 0))
        return -EINVAL;

    /* Wait any pending transfers to finish */
    wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);

    if (copy_from_user(lirc_rx51->wbuf, buf, n))
        return -EFAULT;

    /* Sanity check the input pulses */
    for (i = 0; i < count; i++)
        if (lirc_rx51->wbuf[i] < 0)
            return -EINVAL;

    init_timing_params(lirc_rx51);
    if (count < WBUF_LEN)
        lirc_rx51->wbuf[count] = -1; /* Insert termination mark */

    /*
     * Adjust latency requirements so the device doesn't go in too
     * deep sleep states
     */
    lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, 50);

    lirc_rx51_on(lirc_rx51);
    lirc_rx51->wbuf_index = 1;
    pulse_timer_set_timeout(lirc_rx51, lirc_rx51->wbuf[0]);

    /*
     * Don't return back to the userspace until the transfer has
     * finished
     */
    wait_event_interruptible(lirc_rx51->wqueue, lirc_rx51->wbuf_index < 0);

    /* We can sleep again */
    lirc_rx51->pdata->set_max_mpu_wakeup_lat(lirc_rx51->dev, -1);

    return n;
}

static long lirc_rx51_ioctl(struct file *filep,
            unsigned int cmd, unsigned long arg)
{
    int result;
    unsigned long value;
    unsigned int ivalue;
    struct lirc_rx51 *lirc_rx51 = filep->private_data;

    switch (cmd) {
    case LIRC_GET_SEND_MODE:
        result = put_user(LIRC_MODE_PULSE, (unsigned long *)arg);
        if (result)
            return result;
        break;

    case LIRC_SET_SEND_MODE:
        result = get_user(value, (unsigned long *)arg);
        if (result)
            return result;

        /* only LIRC_MODE_PULSE supported */
        if (value != LIRC_MODE_PULSE)
            return -ENOSYS;
        break;

    case LIRC_GET_REC_MODE:
        result = put_user(0, (unsigned long *) arg);
        if (result)
            return result;
        break;

    case LIRC_GET_LENGTH:
        return -ENOSYS;
        break;

    case LIRC_SET_SEND_DUTY_CYCLE:
        result = get_user(ivalue, (unsigned int *) arg);
        if (result)
            return result;

        if (ivalue <= 0 || ivalue > 100) {
            dev_err(lirc_rx51->dev, ": invalid duty cycle %d\n",
                ivalue);
            return -EINVAL;
        }

        lirc_rx51->duty_cycle = ivalue;
        break;

    case LIRC_SET_SEND_CARRIER:
        result = get_user(ivalue, (unsigned int *) arg);
        if (result)
            return result;

        if (ivalue > 500000 || ivalue < 20000) {
            dev_err(lirc_rx51->dev, ": invalid carrier freq %d\n",
                ivalue);
            return -EINVAL;
        }

        lirc_rx51->freq = ivalue;
        break;

    case LIRC_GET_FEATURES:
        result = put_user(LIRC_RX51_DRIVER_FEATURES,
                  (unsigned long *) arg);
        if (result)
            return result;
        break;

    default:
        return -ENOIOCTLCMD;
    }

    return 0;
}

static int lirc_rx51_open(struct inode *inode, struct file *file)
{
    struct lirc_rx51 *lirc_rx51 = lirc_get_pdata(file);
    BUG_ON(!lirc_rx51);

    file->private_data = lirc_rx51;

    if (test_and_set_bit(1, &lirc_rx51->device_is_open))
        return -EBUSY;

    return lirc_rx51_init_port(lirc_rx51);
}

static int lirc_rx51_release(struct inode *inode, struct file *file)
{
    struct lirc_rx51 *lirc_rx51 = file->private_data;

    lirc_rx51_free_port(lirc_rx51);

    clear_bit(1, &lirc_rx51->device_is_open);

    return 0;
}

static struct lirc_rx51 lirc_rx51 = {
    .freq       = 38000,
    .duty_cycle = 50,
    .wbuf_index = -1,
};

static const struct file_operations lirc_fops = {
    .owner      = THIS_MODULE,
    .write      = lirc_rx51_write,
    .unlocked_ioctl = lirc_rx51_ioctl,
    .read       = lirc_dev_fop_read,
    .poll       = lirc_dev_fop_poll,
    .open       = lirc_rx51_open,
    .release    = lirc_rx51_release,
};

static struct lirc_driver lirc_rx51_driver = {
    .name       = DRIVER_NAME,
    .minor      = -1,
    .code_length    = 1,
    .data       = &lirc_rx51,
    .fops       = &lirc_fops,
    .owner      = THIS_MODULE,
};

#ifdef CONFIG_PM

static int lirc_rx51_suspend(struct platform_device *dev, pm_message_t state)
{
    /*
     * In case the device is still open, do not suspend. Normally
     * this should not be a problem as lircd only keeps the device
     * open only for short periods of time. We also don't want to
     * get involved with race conditions that might happen if we
     * were in a middle of a transmit. Thus, we defer any suspend
     * actions until transmit has completed.
     */
    if (test_and_set_bit(1, &lirc_rx51.device_is_open))
        return -EAGAIN;

    clear_bit(1, &lirc_rx51.device_is_open);

    return 0;
}

static int lirc_rx51_resume(struct platform_device *dev)
{
    return 0;
}

#else

#define lirc_rx51_suspend   NULL
#define lirc_rx51_resume    NULL

#endif /* CONFIG_PM */

static int __devinit lirc_rx51_probe(struct platform_device *dev)
{
    lirc_rx51_driver.features = LIRC_RX51_DRIVER_FEATURES;
    lirc_rx51.pdata = dev->dev.platform_data;
    lirc_rx51.pwm_timer_num = lirc_rx51.pdata->pwm_timer;
    lirc_rx51.dev = &dev->dev;
    lirc_rx51_driver.dev = &dev->dev;
    lirc_rx51_driver.minor = lirc_register_driver(&lirc_rx51_driver);
    init_waitqueue_head(&lirc_rx51.wqueue);

    if (lirc_rx51_driver.minor < 0) {
        dev_err(lirc_rx51.dev, ": lirc_register_driver failed: %d\n",
               lirc_rx51_driver.minor);
        return lirc_rx51_driver.minor;
    }
    dev_info(lirc_rx51.dev, "registration ok, minor: %d, pwm: %d\n",
         lirc_rx51_driver.minor, lirc_rx51.pwm_timer_num);

    return 0;
}

static int __exit lirc_rx51_remove(struct platform_device *dev)
{
    return lirc_unregister_driver(lirc_rx51_driver.minor);
}

struct platform_driver lirc_rx51_platform_driver = {
    .probe      = lirc_rx51_probe,
    .remove     = __exit_p(lirc_rx51_remove),
    .suspend    = lirc_rx51_suspend,
    .resume     = lirc_rx51_resume,
    .driver     = {
        .name   = DRIVER_NAME,
        .owner  = THIS_MODULE,
    },
};

static int __init lirc_rx51_init(void)
{
    return platform_driver_register(&lirc_rx51_platform_driver);
}
module_init(lirc_rx51_init);

static void __exit lirc_rx51_exit(void)
{
    platform_driver_unregister(&lirc_rx51_platform_driver);
}
module_exit(lirc_rx51_exit);

MODULE_DESCRIPTION("LIRC TX driver for Nokia RX51");
MODULE_AUTHOR("Nokia Corporation");
MODULE_LICENSE("GPL");