ir-raw.c

Go to the documentation of this file.

/* ir-raw.c - handle IR pulse/space events
 *
 * Copyright (C) 2010 by Mauro Carvalho Chehab <[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/export.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include "rc-core-priv.h"

/* Define the max number of pulse/space transitions to buffer */
#define MAX_IR_EVENT_SIZE      512

/* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
static LIST_HEAD(ir_raw_client_list);

/* Used to handle IR raw handler extensions */
static DEFINE_MUTEX(ir_raw_handler_lock);
static LIST_HEAD(ir_raw_handler_list);
static u64 available_protocols;

#ifdef MODULE
/* Used to load the decoders */
static struct work_struct wq_load;
#endif

static int ir_raw_event_thread(void *data)
{
    struct ir_raw_event ev;
    struct ir_raw_handler *handler;
    struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
    int retval;

    while (!kthread_should_stop()) {

        spin_lock_irq(&raw->lock);
        retval = kfifo_len(&raw->kfifo);

        if (retval < sizeof(ev)) {
            set_current_state(TASK_INTERRUPTIBLE);

            if (kthread_should_stop())
                set_current_state(TASK_RUNNING);

            spin_unlock_irq(&raw->lock);
            schedule();
            continue;
        }

        retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
        spin_unlock_irq(&raw->lock);

        mutex_lock(&ir_raw_handler_lock);
        list_for_each_entry(handler, &ir_raw_handler_list, list)
            handler->decode(raw->dev, ev);
        raw->prev_ev = ev;
        mutex_unlock(&ir_raw_handler_lock);
    }

    return 0;
}

int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
{
    if (!dev->raw)
        return -EINVAL;

    IR_dprintk(2, "sample: (%05dus %s)\n",
           TO_US(ev->duration), TO_STR(ev->pulse));

    if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
        return -ENOMEM;

    return 0;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store);

int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
{
    ktime_t         now;
    s64         delta; /* ns */
    DEFINE_IR_RAW_EVENT(ev);
    int         rc = 0;
    int         delay;

    if (!dev->raw)
        return -EINVAL;

    now = ktime_get();
    delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
    delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);

    /* Check for a long duration since last event or if we're
     * being called for the first time, note that delta can't
     * possibly be negative.
     */
    if (delta > delay || !dev->raw->last_type)
        type |= IR_START_EVENT;
    else
        ev.duration = delta;

    if (type & IR_START_EVENT)
        ir_raw_event_reset(dev);
    else if (dev->raw->last_type & IR_SPACE) {
        ev.pulse = false;
        rc = ir_raw_event_store(dev, &ev);
    } else if (dev->raw->last_type & IR_PULSE) {
        ev.pulse = true;
        rc = ir_raw_event_store(dev, &ev);
    } else
        return 0;

    dev->raw->last_event = now;
    dev->raw->last_type = type;
    return rc;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);

int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
{
    if (!dev->raw)
        return -EINVAL;

    /* Ignore spaces in idle mode */
    if (dev->idle && !ev->pulse)
        return 0;
    else if (dev->idle)
        ir_raw_event_set_idle(dev, false);

    if (!dev->raw->this_ev.duration)
        dev->raw->this_ev = *ev;
    else if (ev->pulse == dev->raw->this_ev.pulse)
        dev->raw->this_ev.duration += ev->duration;
    else {
        ir_raw_event_store(dev, &dev->raw->this_ev);
        dev->raw->this_ev = *ev;
    }

    /* Enter idle mode if nessesary */
    if (!ev->pulse && dev->timeout &&
        dev->raw->this_ev.duration >= dev->timeout)
        ir_raw_event_set_idle(dev, true);

    return 1;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);

void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
{
    if (!dev->raw)
        return;

    IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");

    if (idle) {
        dev->raw->this_ev.timeout = true;
        ir_raw_event_store(dev, &dev->raw->this_ev);
        init_ir_raw_event(&dev->raw->this_ev);
    }

    if (dev->s_idle)
        dev->s_idle(dev, idle);

    dev->idle = idle;
}
EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);

void ir_raw_event_handle(struct rc_dev *dev)
{
    unsigned long flags;

    if (!dev->raw)
        return;

    spin_lock_irqsave(&dev->raw->lock, flags);
    wake_up_process(dev->raw->thread);
    spin_unlock_irqrestore(&dev->raw->lock, flags);
}
EXPORT_SYMBOL_GPL(ir_raw_event_handle);

/* used internally by the sysfs interface */
u64
ir_raw_get_allowed_protocols(void)
{
    u64 protocols;
    mutex_lock(&ir_raw_handler_lock);
    protocols = available_protocols;
    mutex_unlock(&ir_raw_handler_lock);
    return protocols;
}

/*
 * Used to (un)register raw event clients
 */
int ir_raw_event_register(struct rc_dev *dev)
{
    int rc;
    struct ir_raw_handler *handler;

    if (!dev)
        return -EINVAL;

    dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
    if (!dev->raw)
        return -ENOMEM;

    dev->raw->dev = dev;
    dev->raw->enabled_protocols = ~0;
    rc = kfifo_alloc(&dev->raw->kfifo,
             sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
             GFP_KERNEL);
    if (rc < 0)
        goto out;

    spin_lock_init(&dev->raw->lock);
    dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
                       "rc%ld", dev->devno);

    if (IS_ERR(dev->raw->thread)) {
        rc = PTR_ERR(dev->raw->thread);
        goto out;
    }

    mutex_lock(&ir_raw_handler_lock);
    list_add_tail(&dev->raw->list, &ir_raw_client_list);
    list_for_each_entry(handler, &ir_raw_handler_list, list)
        if (handler->raw_register)
            handler->raw_register(dev);
    mutex_unlock(&ir_raw_handler_lock);

    return 0;

out:
    kfree(dev->raw);
    dev->raw = NULL;
    return rc;
}

void ir_raw_event_unregister(struct rc_dev *dev)
{
    struct ir_raw_handler *handler;

    if (!dev || !dev->raw)
        return;

    kthread_stop(dev->raw->thread);

    mutex_lock(&ir_raw_handler_lock);
    list_del(&dev->raw->list);
    list_for_each_entry(handler, &ir_raw_handler_list, list)
        if (handler->raw_unregister)
            handler->raw_unregister(dev);
    mutex_unlock(&ir_raw_handler_lock);

    kfifo_free(&dev->raw->kfifo);
    kfree(dev->raw);
    dev->raw = NULL;
}

/*
 * Extension interface - used to register the IR decoders
 */

int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
{
    struct ir_raw_event_ctrl *raw;

    mutex_lock(&ir_raw_handler_lock);
    list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
    if (ir_raw_handler->raw_register)
        list_for_each_entry(raw, &ir_raw_client_list, list)
            ir_raw_handler->raw_register(raw->dev);
    available_protocols |= ir_raw_handler->protocols;
    mutex_unlock(&ir_raw_handler_lock);

    return 0;
}
EXPORT_SYMBOL(ir_raw_handler_register);

void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
{
    struct ir_raw_event_ctrl *raw;

    mutex_lock(&ir_raw_handler_lock);
    list_del(&ir_raw_handler->list);
    if (ir_raw_handler->raw_unregister)
        list_for_each_entry(raw, &ir_raw_client_list, list)
            ir_raw_handler->raw_unregister(raw->dev);
    available_protocols &= ~ir_raw_handler->protocols;
    mutex_unlock(&ir_raw_handler_lock);
}
EXPORT_SYMBOL(ir_raw_handler_unregister);

#ifdef MODULE
static void init_decoders(struct work_struct *work)
{
    /* Load the decoder modules */

    load_nec_decode();
    load_rc5_decode();
    load_rc6_decode();
    load_jvc_decode();
    load_sony_decode();
    load_sanyo_decode();
    load_mce_kbd_decode();
    load_lirc_codec();

    /* If needed, we may later add some init code. In this case,
       it is needed to change the CONFIG_MODULE test at rc-core.h
     */
}
#endif

void ir_raw_init(void)
{
#ifdef MODULE
    INIT_WORK(&wq_load, init_decoders);
    schedule_work(&wq_load);
#endif
}