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linux/drivers/media/IR/ir-raw-event.c
Mauro Carvalho Chehab a3572c34da V4L/DVB: ir-core: Add logic to decode IR protocols at the IR core
Adds a method to pass IR raw pulse/code events into ir-core. This is
needed in order to support LIRC. It also helps to move common code
from the drivers into the core.

In order to allow testing, it implements a simple NEC protocol decoder
at ir-nec-decoder.c file. The logic is about the same used at saa7134
driver that handles Avermedia M135A and Encore FM53 boards.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-05-18 00:52:56 -03:00

118 lines
2.9 KiB
C

/* 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 <media/ir-core.h>
/* Define the max number of bit transitions per IR keycode */
#define MAX_IR_EVENT_SIZE 256
int ir_raw_event_register(struct input_dev *input_dev)
{
struct ir_input_dev *ir = input_get_drvdata(input_dev);
int rc, size;
ir->raw = kzalloc(sizeof(*ir->raw), GFP_KERNEL);
size = sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE * 2;
size = roundup_pow_of_two(size);
rc = kfifo_alloc(&ir->raw->kfifo, size, GFP_KERNEL);
return rc;
}
EXPORT_SYMBOL_GPL(ir_raw_event_register);
void ir_raw_event_unregister(struct input_dev *input_dev)
{
struct ir_input_dev *ir = input_get_drvdata(input_dev);
if (!ir->raw)
return;
kfifo_free(&ir->raw->kfifo);
kfree(ir->raw);
ir->raw = NULL;
}
EXPORT_SYMBOL_GPL(ir_raw_event_unregister);
int ir_raw_event_store(struct input_dev *input_dev, enum raw_event_type type)
{
struct ir_input_dev *ir = input_get_drvdata(input_dev);
struct timespec ts;
struct ir_raw_event event;
int rc;
if (!ir->raw)
return -EINVAL;
event.type = type;
event.delta.tv_sec = 0;
event.delta.tv_nsec = 0;
ktime_get_ts(&ts);
if (timespec_equal(&ir->raw->last_event, &event.delta))
event.type |= IR_START_EVENT;
else
event.delta = timespec_sub(ts, ir->raw->last_event);
memcpy(&ir->raw->last_event, &ts, sizeof(ts));
if (event.delta.tv_sec) {
event.type |= IR_START_EVENT;
event.delta.tv_sec = 0;
event.delta.tv_nsec = 0;
}
kfifo_in(&ir->raw->kfifo, &event, sizeof(event));
return rc;
}
EXPORT_SYMBOL_GPL(ir_raw_event_store);
int ir_raw_event_handle(struct input_dev *input_dev)
{
struct ir_input_dev *ir = input_get_drvdata(input_dev);
int rc;
struct ir_raw_event *evs;
int len, i;
/*
* Store the events into a temporary buffer. This allows calling more than
* one decoder to deal with the received data
*/
len = kfifo_len(&ir->raw->kfifo) / sizeof(*evs);
if (!len)
return 0;
evs = kmalloc(len * sizeof(*evs), GFP_ATOMIC);
for (i = 0; i < len; i++) {
rc = kfifo_out(&ir->raw->kfifo, &evs[i], sizeof(*evs));
if (rc != sizeof(*evs)) {
IR_dprintk(1, "overflow error: received %d instead of %zd\n",
rc, sizeof(*evs));
return -EINVAL;
}
IR_dprintk(2, "event type %d, time before event: %07luus\n",
evs[i].type, (evs[i].delta.tv_nsec + 500) / 1000);
}
rc = ir_nec_decode(input_dev, evs, len);
kfree(evs);
return rc;
}
EXPORT_SYMBOL_GPL(ir_raw_event_handle);