1 /* ir-raw-event.c - handle IR Pulse/Space event
3 * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation version 2 of the License.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/workqueue.h>
16 #include <linux/spinlock.h>
17 #include <linux/sched.h>
18 #include "ir-core-priv.h"
20 /* Define the max number of pulse/space transitions to buffer */
21 #define MAX_IR_EVENT_SIZE 512
23 /* Used to handle IR raw handler extensions */
24 static LIST_HEAD(ir_raw_handler_list);
25 static DEFINE_SPINLOCK(ir_raw_handler_lock);
28 * RUN_DECODER() - runs an operation on all IR decoders
29 * @ops: IR raw handler operation to be called
30 * @arg: arguments to be passed to the callback
32 * Calls ir_raw_handler::ops for all registered IR handlers. It prevents
33 * new decode addition/removal while running, by locking ir_raw_handler_lock
34 * mutex. If an error occurs, we keep going, as in the decode case, each
35 * decoder must have a crack at decoding the data. We return a sum of the
36 * return codes, which will be either 0 or negative for current callers.
38 #define RUN_DECODER(ops, ...) ({ \
39 struct ir_raw_handler *_ir_raw_handler; \
40 int _sumrc = 0, _rc; \
41 spin_lock(&ir_raw_handler_lock); \
42 list_for_each_entry(_ir_raw_handler, &ir_raw_handler_list, list) { \
43 if (_ir_raw_handler->ops) { \
44 _rc = _ir_raw_handler->ops(__VA_ARGS__); \
48 spin_unlock(&ir_raw_handler_lock); \
53 /* Used to load the decoders */
54 static struct work_struct wq_load;
57 static void ir_raw_event_work(struct work_struct *work)
59 struct ir_raw_event ev;
60 struct ir_raw_event_ctrl *raw =
61 container_of(work, struct ir_raw_event_ctrl, rx_work);
63 while (kfifo_out(&raw->kfifo, &ev, sizeof(ev)) == sizeof(ev))
64 RUN_DECODER(decode, raw->input_dev, ev);
67 int ir_raw_event_register(struct input_dev *input_dev)
69 struct ir_input_dev *ir = input_get_drvdata(input_dev);
72 ir->raw = kzalloc(sizeof(*ir->raw), GFP_KERNEL);
76 ir->raw->input_dev = input_dev;
77 INIT_WORK(&ir->raw->rx_work, ir_raw_event_work);
79 rc = kfifo_alloc(&ir->raw->kfifo, sizeof(s64) * MAX_IR_EVENT_SIZE,
87 rc = RUN_DECODER(raw_register, input_dev);
89 kfifo_free(&ir->raw->kfifo);
98 void ir_raw_event_unregister(struct input_dev *input_dev)
100 struct ir_input_dev *ir = input_get_drvdata(input_dev);
105 cancel_work_sync(&ir->raw->rx_work);
106 RUN_DECODER(raw_unregister, input_dev);
108 kfifo_free(&ir->raw->kfifo);
114 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
115 * @input_dev: the struct input_dev device descriptor
116 * @ev: the struct ir_raw_event descriptor of the pulse/space
118 * This routine (which may be called from an interrupt context) stores a
119 * pulse/space duration for the raw ir decoding state machines. Pulses are
120 * signalled as positive values and spaces as negative values. A zero value
121 * will reset the decoding state machines.
123 int ir_raw_event_store(struct input_dev *input_dev, struct ir_raw_event *ev)
125 struct ir_input_dev *ir = input_get_drvdata(input_dev);
130 if (kfifo_in(&ir->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
135 EXPORT_SYMBOL_GPL(ir_raw_event_store);
138 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
139 * @input_dev: the struct input_dev device descriptor
140 * @type: the type of the event that has occurred
142 * This routine (which may be called from an interrupt context) is used to
143 * store the beginning of an ir pulse or space (or the start/end of ir
144 * reception) for the raw ir decoding state machines. This is used by
145 * hardware which does not provide durations directly but only interrupts
146 * (or similar events) on state change.
148 int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type type)
150 struct ir_input_dev *ir = input_get_drvdata(input_dev);
153 struct ir_raw_event ev;
160 delta = ktime_to_ns(ktime_sub(now, ir->raw->last_event));
162 /* Check for a long duration since last event or if we're
163 * being called for the first time, note that delta can't
164 * possibly be negative.
167 if (delta > IR_MAX_DURATION || !ir->raw->last_type)
168 type |= IR_START_EVENT;
172 if (type & IR_START_EVENT)
173 ir_raw_event_reset(input_dev);
174 else if (ir->raw->last_type & IR_SPACE) {
176 rc = ir_raw_event_store(input_dev, &ev);
177 } else if (ir->raw->last_type & IR_PULSE) {
179 rc = ir_raw_event_store(input_dev, &ev);
183 ir->raw->last_event = now;
184 ir->raw->last_type = type;
187 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
190 * ir_raw_event_handle() - schedules the decoding of stored ir data
191 * @input_dev: the struct input_dev device descriptor
193 * This routine will signal the workqueue to start decoding stored ir data.
195 void ir_raw_event_handle(struct input_dev *input_dev)
197 struct ir_input_dev *ir = input_get_drvdata(input_dev);
202 schedule_work(&ir->raw->rx_work);
204 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
207 * Extension interface - used to register the IR decoders
210 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
212 spin_lock(&ir_raw_handler_lock);
213 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
214 spin_unlock(&ir_raw_handler_lock);
217 EXPORT_SYMBOL(ir_raw_handler_register);
219 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
221 spin_lock(&ir_raw_handler_lock);
222 list_del(&ir_raw_handler->list);
223 spin_unlock(&ir_raw_handler_lock);
225 EXPORT_SYMBOL(ir_raw_handler_unregister);
228 static void init_decoders(struct work_struct *work)
230 /* Load the decoder modules */
238 /* If needed, we may later add some init code. In this case,
239 it is needed to change the CONFIG_MODULE test at ir-core.h
244 void ir_raw_init(void)
247 INIT_WORK(&wq_load, init_decoders);
248 schedule_work(&wq_load);