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, it stops the ops. Otherwise, it returns a sum
35 * of the return codes.
37 #define RUN_DECODER(ops, ...) ({ \
38 struct ir_raw_handler *_ir_raw_handler; \
39 int _sumrc = 0, _rc; \
40 spin_lock(&ir_raw_handler_lock); \
41 list_for_each_entry(_ir_raw_handler, &ir_raw_handler_list, list) { \
42 if (_ir_raw_handler->ops) { \
43 _rc = _ir_raw_handler->ops(__VA_ARGS__); \
49 spin_unlock(&ir_raw_handler_lock); \
54 /* Used to load the decoders */
55 static struct work_struct wq_load;
58 static void ir_raw_event_work(struct work_struct *work)
61 struct ir_raw_event_ctrl *raw =
62 container_of(work, struct ir_raw_event_ctrl, rx_work);
64 while (kfifo_out(&raw->kfifo, &d, sizeof(d)) == sizeof(d))
65 RUN_DECODER(decode, raw->input_dev, d);
68 int ir_raw_event_register(struct input_dev *input_dev)
70 struct ir_input_dev *ir = input_get_drvdata(input_dev);
73 ir->raw = kzalloc(sizeof(*ir->raw), GFP_KERNEL);
77 ir->raw->input_dev = input_dev;
78 INIT_WORK(&ir->raw->rx_work, ir_raw_event_work);
80 rc = kfifo_alloc(&ir->raw->kfifo, sizeof(s64) * MAX_IR_EVENT_SIZE,
88 rc = RUN_DECODER(raw_register, input_dev);
90 kfifo_free(&ir->raw->kfifo);
99 void ir_raw_event_unregister(struct input_dev *input_dev)
101 struct ir_input_dev *ir = input_get_drvdata(input_dev);
106 cancel_work_sync(&ir->raw->rx_work);
107 RUN_DECODER(raw_unregister, input_dev);
109 kfifo_free(&ir->raw->kfifo);
115 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
116 * @input_dev: the struct input_dev device descriptor
117 * @duration: duration of the pulse or space in ns
119 * This routine (which may be called from an interrupt context) stores a
120 * pulse/space duration for the raw ir decoding state machines. Pulses are
121 * signalled as positive values and spaces as negative values. A zero value
122 * will reset the decoding state machines.
124 int ir_raw_event_store(struct input_dev *input_dev, s64 duration)
126 struct ir_input_dev *ir = input_get_drvdata(input_dev);
131 if (kfifo_in(&ir->raw->kfifo, &duration, sizeof(duration)) != sizeof(duration))
136 EXPORT_SYMBOL_GPL(ir_raw_event_store);
139 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
140 * @input_dev: the struct input_dev device descriptor
141 * @type: the type of the event that has occurred
143 * This routine (which may be called from an interrupt context) is used to
144 * store the beginning of an ir pulse or space (or the start/end of ir
145 * reception) for the raw ir decoding state machines. This is used by
146 * hardware which does not provide durations directly but only interrupts
147 * (or similar events) on state change.
149 int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type type)
151 struct ir_input_dev *ir = input_get_drvdata(input_dev);
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.
166 if (delta > NSEC_PER_SEC || !ir->raw->last_type)
167 type |= IR_START_EVENT;
169 if (type & IR_START_EVENT)
170 ir_raw_event_reset(input_dev);
171 else if (ir->raw->last_type & IR_SPACE)
172 rc = ir_raw_event_store(input_dev, -delta);
173 else if (ir->raw->last_type & IR_PULSE)
174 rc = ir_raw_event_store(input_dev, delta);
178 ir->raw->last_event = now;
179 ir->raw->last_type = type;
182 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
185 * ir_raw_event_handle() - schedules the decoding of stored ir data
186 * @input_dev: the struct input_dev device descriptor
188 * This routine will signal the workqueue to start decoding stored ir data.
190 void ir_raw_event_handle(struct input_dev *input_dev)
192 struct ir_input_dev *ir = input_get_drvdata(input_dev);
197 schedule_work(&ir->raw->rx_work);
199 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
202 * Extension interface - used to register the IR decoders
205 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
207 spin_lock(&ir_raw_handler_lock);
208 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
209 spin_unlock(&ir_raw_handler_lock);
212 EXPORT_SYMBOL(ir_raw_handler_register);
214 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
216 spin_lock(&ir_raw_handler_lock);
217 list_del(&ir_raw_handler->list);
218 spin_unlock(&ir_raw_handler_lock);
220 EXPORT_SYMBOL(ir_raw_handler_unregister);
223 static void init_decoders(struct work_struct *work)
225 /* Load the decoder modules */
230 /* If needed, we may later add some init code. In this case,
231 it is needed to change the CONFIG_MODULE test at ir-core.h
236 void ir_raw_init(void)
239 INIT_WORK(&wq_load, init_decoders);
240 schedule_work(&wq_load);