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linux/drivers/media/IR/ir-raw-event.c
David Härdeman 667c9ebe97 V4L/DVB: ir-core: centralize sysfs raw decoder enabling/disabling
With the current logic, each raw decoder needs to add a copy of the exact
same sysfs code. This is both unnecessary and also means that (re)loading
an IR driver after raw decoder modules have been loaded won't work as
expected.

This patch moves that logic into ir-raw-event and adds a single sysfs
file per device.

Reading that file returns something like:

	"rc5 [rc6] nec jvc [sony]"

(with enabled protocols in [] brackets)

Writing either "+protocol" or "-protocol" to that file will
enable or disable the according protocol decoder.

An additional benefit is that the disabling of a decoder will be
remembered across module removal/insertion so a previously
disabled decoder won't suddenly be activated again. The default
setting is to enable all decoders.

This is also necessary for the next patch which moves even more decoder
state into the central raw decoding structs.

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-08-02 14:54:27 -03:00

269 lines
7.2 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 <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 DEFINE_SPINLOCK(ir_raw_handler_lock);
static LIST_HEAD(ir_raw_handler_list);
static u64 available_protocols;
/**
* 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, we keep going, as in the decode case, each
* decoder must have a crack at decoding the data. We return a sum of the
* return codes, which will be either 0 or negative for current callers.
*/
#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__); \
_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);
}
/**
* 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);
/* used internally by the sysfs interface */
u64
ir_raw_get_allowed_protocols()
{
u64 protocols;
spin_lock(&ir_raw_handler_lock);
protocols = available_protocols;
spin_unlock(&ir_raw_handler_lock);
return protocols;
}
/*
* Used to (un)register raw event clients
*/
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);
ir->raw->enabled_protocols = ~0;
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;
}
/*
* 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);
available_protocols |= ir_raw_handler->protocols;
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);
available_protocols &= ~ir_raw_handler->protocols;
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
}