ir-lirc-codec.c

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/* ir-lirc-codec.c - rc-core to classic lirc interface bridge
 *
 * Copyright (C) 2010 by Jarod Wilson <[email protected]>
 *
 * 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 version 2 of the License.
 *
 *  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.
 */

#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/module.h>
#include <media/lirc.h>
#include <media/lirc_dev.h>
#include <media/rc-core.h>
#include "rc-core-priv.h"

#define LIRCBUF_SIZE 256

static int ir_lirc_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
    struct lirc_codec *lirc = &dev->raw->lirc;
    int sample;

    if (!(dev->raw->enabled_protocols & RC_TYPE_LIRC))
        return 0;

    if (!dev->raw->lirc.drv || !dev->raw->lirc.drv->rbuf)
        return -EINVAL;

    /* Packet start */
    if (ev.reset)
        return 0;

    /* Carrier reports */
    if (ev.carrier_report) {
        sample = LIRC_FREQUENCY(ev.carrier);
        IR_dprintk(2, "carrier report (freq: %d)\n", sample);

    /* Packet end */
    } else if (ev.timeout) {

        if (lirc->gap)
            return 0;

        lirc->gap_start = ktime_get();
        lirc->gap = true;
        lirc->gap_duration = ev.duration;

        if (!lirc->send_timeout_reports)
            return 0;

        sample = LIRC_TIMEOUT(ev.duration / 1000);
        IR_dprintk(2, "timeout report (duration: %d)\n", sample);

    /* Normal sample */
    } else {

        if (lirc->gap) {
            int gap_sample;

            lirc->gap_duration += ktime_to_ns(ktime_sub(ktime_get(),
                lirc->gap_start));

            /* Convert to ms and cap by LIRC_VALUE_MASK */
            do_div(lirc->gap_duration, 1000);
            lirc->gap_duration = min(lirc->gap_duration,
                            (u64)LIRC_VALUE_MASK);

            gap_sample = LIRC_SPACE(lirc->gap_duration);
            lirc_buffer_write(dev->raw->lirc.drv->rbuf,
                        (unsigned char *) &gap_sample);
            lirc->gap = false;
        }

        sample = ev.pulse ? LIRC_PULSE(ev.duration / 1000) :
                    LIRC_SPACE(ev.duration / 1000);
        IR_dprintk(2, "delivering %uus %s to lirc_dev\n",
               TO_US(ev.duration), TO_STR(ev.pulse));
    }

    lirc_buffer_write(dev->raw->lirc.drv->rbuf,
              (unsigned char *) &sample);
    wake_up(&dev->raw->lirc.drv->rbuf->wait_poll);

    return 0;
}

static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
                   size_t n, loff_t *ppos)
{
    struct lirc_codec *lirc;
    struct rc_dev *dev;
    unsigned int *txbuf; /* buffer with values to transmit */
    ssize_t ret = -EINVAL;
    size_t count;
    ktime_t start;
    s64 towait;
    unsigned int duration = 0; /* signal duration in us */
    int i;

    start = ktime_get();

    lirc = lirc_get_pdata(file);
    if (!lirc)
        return -EFAULT;

    if (n < sizeof(unsigned) || n % sizeof(unsigned))
        return -EINVAL;

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

    txbuf = memdup_user(buf, n);
    if (IS_ERR(txbuf))
        return PTR_ERR(txbuf);

    dev = lirc->dev;
    if (!dev) {
        ret = -EFAULT;
        goto out;
    }

    if (!dev->tx_ir) {
        ret = -ENOSYS;
        goto out;
    }

    ret = dev->tx_ir(dev, txbuf, count);
    if (ret < 0)
        goto out;

    for (i = 0; i < ret; i++)
        duration += txbuf[i];

    ret *= sizeof(unsigned int);

    /*
     * The lircd gap calculation expects the write function to
     * wait for the actual IR signal to be transmitted before
     * returning.
     */
    towait = ktime_us_delta(ktime_add_us(start, duration), ktime_get());
    if (towait > 0) {
        set_current_state(TASK_INTERRUPTIBLE);
        schedule_timeout(usecs_to_jiffies(towait));
    }

out:
    kfree(txbuf);
    return ret;
}

static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
            unsigned long arg)
{
    struct lirc_codec *lirc;
    struct rc_dev *dev;
    u32 __user *argp = (u32 __user *)(arg);
    int ret = 0;
    __u32 val = 0, tmp;

    lirc = lirc_get_pdata(filep);
    if (!lirc)
        return -EFAULT;

    dev = lirc->dev;
    if (!dev)
        return -EFAULT;

    if (_IOC_DIR(cmd) & _IOC_WRITE) {
        ret = get_user(val, argp);
        if (ret)
            return ret;
    }

    switch (cmd) {

    /* legacy support */
    case LIRC_GET_SEND_MODE:
        val = LIRC_CAN_SEND_PULSE & LIRC_CAN_SEND_MASK;
        break;

    case LIRC_SET_SEND_MODE:
        if (val != (LIRC_MODE_PULSE & LIRC_CAN_SEND_MASK))
            return -EINVAL;
        return 0;

    /* TX settings */
    case LIRC_SET_TRANSMITTER_MASK:
        if (!dev->s_tx_mask)
            return -ENOSYS;

        return dev->s_tx_mask(dev, val);

    case LIRC_SET_SEND_CARRIER:
        if (!dev->s_tx_carrier)
            return -ENOSYS;

        return dev->s_tx_carrier(dev, val);

    case LIRC_SET_SEND_DUTY_CYCLE:
        if (!dev->s_tx_duty_cycle)
            return -ENOSYS;

        if (val <= 0 || val >= 100)
            return -EINVAL;

        return dev->s_tx_duty_cycle(dev, val);

    /* RX settings */
    case LIRC_SET_REC_CARRIER:
        if (!dev->s_rx_carrier_range)
            return -ENOSYS;

        if (val <= 0)
            return -EINVAL;

        return dev->s_rx_carrier_range(dev,
                           dev->raw->lirc.carrier_low,
                           val);

    case LIRC_SET_REC_CARRIER_RANGE:
        if (val <= 0)
            return -EINVAL;

        dev->raw->lirc.carrier_low = val;
        return 0;

    case LIRC_GET_REC_RESOLUTION:
        val = dev->rx_resolution;
        break;

    case LIRC_SET_WIDEBAND_RECEIVER:
        if (!dev->s_learning_mode)
            return -ENOSYS;

        return dev->s_learning_mode(dev, !!val);

    case LIRC_SET_MEASURE_CARRIER_MODE:
        if (!dev->s_carrier_report)
            return -ENOSYS;

        return dev->s_carrier_report(dev, !!val);

    /* Generic timeout support */
    case LIRC_GET_MIN_TIMEOUT:
        if (!dev->max_timeout)
            return -ENOSYS;
        val = dev->min_timeout / 1000;
        break;

    case LIRC_GET_MAX_TIMEOUT:
        if (!dev->max_timeout)
            return -ENOSYS;
        val = dev->max_timeout / 1000;
        break;

    case LIRC_SET_REC_TIMEOUT:
        if (!dev->max_timeout)
            return -ENOSYS;

        tmp = val * 1000;

        if (tmp < dev->min_timeout ||
            tmp > dev->max_timeout)
                return -EINVAL;

        dev->timeout = tmp;
        break;

    case LIRC_SET_REC_TIMEOUT_REPORTS:
        lirc->send_timeout_reports = !!val;
        break;

    default:
        return lirc_dev_fop_ioctl(filep, cmd, arg);
    }

    if (_IOC_DIR(cmd) & _IOC_READ)
        ret = put_user(val, argp);

    return ret;
}

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

static void ir_lirc_close(void *data)
{
    return;
}

static struct file_operations lirc_fops = {
    .owner      = THIS_MODULE,
    .write      = ir_lirc_transmit_ir,
    .unlocked_ioctl = ir_lirc_ioctl,
#ifdef CONFIG_COMPAT
    .compat_ioctl   = ir_lirc_ioctl,
#endif
    .read       = lirc_dev_fop_read,
    .poll       = lirc_dev_fop_poll,
    .open       = lirc_dev_fop_open,
    .release    = lirc_dev_fop_close,
    .llseek     = no_llseek,
};

static int ir_lirc_register(struct rc_dev *dev)
{
    struct lirc_driver *drv;
    struct lirc_buffer *rbuf;
    int rc = -ENOMEM;
    unsigned long features;

    drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
    if (!drv)
        return rc;

    rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
    if (!rbuf)
        goto rbuf_alloc_failed;

    rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
    if (rc)
        goto rbuf_init_failed;

    features = LIRC_CAN_REC_MODE2;
    if (dev->tx_ir) {
        features |= LIRC_CAN_SEND_PULSE;
        if (dev->s_tx_mask)
            features |= LIRC_CAN_SET_TRANSMITTER_MASK;
        if (dev->s_tx_carrier)
            features |= LIRC_CAN_SET_SEND_CARRIER;
        if (dev->s_tx_duty_cycle)
            features |= LIRC_CAN_SET_SEND_DUTY_CYCLE;
    }

    if (dev->s_rx_carrier_range)
        features |= LIRC_CAN_SET_REC_CARRIER |
            LIRC_CAN_SET_REC_CARRIER_RANGE;

    if (dev->s_learning_mode)
        features |= LIRC_CAN_USE_WIDEBAND_RECEIVER;

    if (dev->s_carrier_report)
        features |= LIRC_CAN_MEASURE_CARRIER;

    if (dev->max_timeout)
        features |= LIRC_CAN_SET_REC_TIMEOUT;

    snprintf(drv->name, sizeof(drv->name), "ir-lirc-codec (%s)",
         dev->driver_name);
    drv->minor = -1;
    drv->features = features;
    drv->data = &dev->raw->lirc;
    drv->rbuf = rbuf;
    drv->set_use_inc = &ir_lirc_open;
    drv->set_use_dec = &ir_lirc_close;
    drv->code_length = sizeof(struct ir_raw_event) * 8;
    drv->fops = &lirc_fops;
    drv->dev = &dev->dev;
    drv->owner = THIS_MODULE;

    drv->minor = lirc_register_driver(drv);
    if (drv->minor < 0) {
        rc = -ENODEV;
        goto lirc_register_failed;
    }

    dev->raw->lirc.drv = drv;
    dev->raw->lirc.dev = dev;
    return 0;

lirc_register_failed:
rbuf_init_failed:
    kfree(rbuf);
rbuf_alloc_failed:
    kfree(drv);

    return rc;
}

static int ir_lirc_unregister(struct rc_dev *dev)
{
    struct lirc_codec *lirc = &dev->raw->lirc;

    lirc_unregister_driver(lirc->drv->minor);
    lirc_buffer_free(lirc->drv->rbuf);
    kfree(lirc->drv);

    return 0;
}

static struct ir_raw_handler lirc_handler = {
    .protocols  = RC_TYPE_LIRC,
    .decode     = ir_lirc_decode,
    .raw_register   = ir_lirc_register,
    .raw_unregister = ir_lirc_unregister,
};

static int __init ir_lirc_codec_init(void)
{
    ir_raw_handler_register(&lirc_handler);

    printk(KERN_INFO "IR LIRC bridge handler initialized\n");
    return 0;
}

static void __exit ir_lirc_codec_exit(void)
{
    ir_raw_handler_unregister(&lirc_handler);
}

module_init(ir_lirc_codec_init);
module_exit(ir_lirc_codec_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jarod Wilson <[email protected]>");
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
MODULE_DESCRIPTION("LIRC IR handler bridge");