[openwrt/staging/blogic.git] /

/* ir-raw-event.c - handle IR Pulse/Space event
 *
 * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
 *
 * 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/workqueue.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include "ir-core-priv.h"

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

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

/**
 * RUN_DECODER()        - runs an operation on all IR decoders
 * @ops:        IR raw handler operation to be called
 * @arg:        arguments to be passed to the callback
 *
 * Calls ir_raw_handler::ops for all registered IR handlers. It prevents
 * new decode addition/removal while running, by locking ir_raw_handler_lock
 * mutex. If an error occurs, it stops the ops. Otherwise, it returns a sum
 * of the return codes.
 */
#define RUN_DECODER(ops, ...) ({                                            \
        struct ir_raw_handler           *_ir_raw_handler;                   \
        int _sumrc = 0, _rc;                                                \
        spin_lock(&ir_raw_handler_lock);                                    \
        list_for_each_entry(_ir_raw_handler, &ir_raw_handler_list, list) {  \
                if (_ir_raw_handler->ops) {                                 \
                        _rc = _ir_raw_handler->ops(__VA_ARGS__);            \
                        if (_rc < 0)                                        \
                                break;                                      \
                        _sumrc += _rc;                                      \
                }                                                           \
        }                                                                   \
        spin_unlock(&ir_raw_handler_lock);                                  \
        _sumrc;                                                             \
})

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

static void ir_raw_event_work(struct work_struct *work)
{
        struct ir_raw_event ev;
        struct ir_raw_event_ctrl *raw =
                container_of(work, struct ir_raw_event_ctrl, rx_work);

        while (kfifo_out(&raw->kfifo, &ev, sizeof(ev)) == sizeof(ev))
                RUN_DECODER(decode, raw->input_dev, ev);
}

int ir_raw_event_register(struct input_dev *input_dev)
{
        struct ir_input_dev *ir = input_get_drvdata(input_dev);
        int rc;

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

        ir->raw->input_dev = input_dev;
        INIT_WORK(&ir->raw->rx_work, ir_raw_event_work);

        rc = kfifo_alloc(&ir->raw->kfifo, sizeof(s64) * MAX_IR_EVENT_SIZE,
                         GFP_KERNEL);
        if (rc < 0) {
                kfree(ir->raw);
                ir->raw = NULL;
                return rc;
        }

        rc = RUN_DECODER(raw_register, input_dev);
        if (rc < 0) {
                kfifo_free(&ir->raw->kfifo);
                kfree(ir->raw);
                ir->raw = NULL;
                return rc;
        }

        return rc;
}

void ir_raw_event_unregister(struct input_dev *input_dev)
{
        struct ir_input_dev *ir = input_get_drvdata(input_dev);

        if (!ir->raw)
                return;

        cancel_work_sync(&ir->raw->rx_work);
        RUN_DECODER(raw_unregister, input_dev);

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

/**
 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
 * @input_dev:  the struct input_dev device descriptor
 * @ev:         the struct ir_raw_event descriptor of the pulse/space
 *
 * This routine (which may be called from an interrupt context) stores a
 * pulse/space duration for the raw ir decoding state machines. Pulses are
 * signalled as positive values and spaces as negative values. A zero value
 * will reset the decoding state machines.
 */
int ir_raw_event_store(struct input_dev *input_dev, struct ir_raw_event *ev)
{
        struct ir_input_dev *ir = input_get_drvdata(input_dev);

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

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

        return 0;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store);

/**
 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
 * @input_dev:  the struct input_dev device descriptor
 * @type:       the type of the event that has occurred
 *
 * This routine (which may be called from an interrupt context) is used to
 * store the beginning of an ir pulse or space (or the start/end of ir
 * reception) for the raw ir decoding state machines. This is used by
 * hardware which does not provide durations directly but only interrupts
 * (or similar events) on state change.
 */
int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type type)
{
        struct ir_input_dev     *ir = input_get_drvdata(input_dev);
        ktime_t                 now;
        s64                     delta; /* ns */
        struct ir_raw_event     ev;
        int                     rc = 0;

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

        now = ktime_get();
        delta = ktime_to_ns(ktime_sub(now, ir->raw->last_event));

        /* 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.
         */
        ev.duration = 0;
        if (delta > IR_MAX_DURATION || !ir->raw->last_type)
                type |= IR_START_EVENT;
        else
                ev.duration = delta;

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

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

/**
 * ir_raw_event_handle() - schedules the decoding of stored ir data
 * @input_dev:  the struct input_dev device descriptor
 *
 * This routine will signal the workqueue to start decoding stored ir data.
 */
void ir_raw_event_handle(struct input_dev *input_dev)
{
        struct ir_input_dev *ir = input_get_drvdata(input_dev);

        if (!ir->raw)
                return;

        schedule_work(&ir->raw->rx_work);
}
EXPORT_SYMBOL_GPL(ir_raw_event_handle);

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

int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
{
        spin_lock(&ir_raw_handler_lock);
        list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
        spin_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)
{
        spin_lock(&ir_raw_handler_lock);
        list_del(&ir_raw_handler->list);
        spin_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();

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

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