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 <media/ir-core.h>
16 #include <linux/workqueue.h>
17 #include <linux/spinlock.h>
18 #include <linux/sched.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;
57 static void ir_raw_event_work(struct work_struct *work)
60 struct ir_raw_event_ctrl *raw =
61 container_of(work, struct ir_raw_event_ctrl, rx_work);
63 while (kfifo_out(&raw->kfifo, &d, sizeof(d)) == sizeof(d))
64 RUN_DECODER(decode, raw->input_dev, d);
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 * @duration: duration of the pulse or space in ns
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, s64 duration)
125 struct ir_input_dev *ir = input_get_drvdata(input_dev);
130 if (kfifo_in(&ir->raw->kfifo, &duration, sizeof(duration)) != sizeof(duration))
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);
159 delta = ktime_to_ns(ktime_sub(now, ir->raw->last_event));
161 /* Check for a long duration since last event or if we're
162 * being called for the first time, note that delta can't
163 * possibly be negative.
165 if (delta > NSEC_PER_SEC || !ir->raw->last_type)
166 type |= IR_START_EVENT;
168 if (type & IR_START_EVENT)
169 ir_raw_event_reset(input_dev);
170 else if (ir->raw->last_type & IR_SPACE)
171 rc = ir_raw_event_store(input_dev, -delta);
172 else if (ir->raw->last_type & IR_PULSE)
173 rc = ir_raw_event_store(input_dev, delta);
177 ir->raw->last_event = now;
178 ir->raw->last_type = type;
181 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
184 * ir_raw_event_handle() - schedules the decoding of stored ir data
185 * @input_dev: the struct input_dev device descriptor
187 * This routine will signal the workqueue to start decoding stored ir data.
189 void ir_raw_event_handle(struct input_dev *input_dev)
191 struct ir_input_dev *ir = input_get_drvdata(input_dev);
196 schedule_work(&ir->raw->rx_work);
198 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
201 * Extension interface - used to register the IR decoders
204 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
206 spin_lock(&ir_raw_handler_lock);
207 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
208 spin_unlock(&ir_raw_handler_lock);
211 EXPORT_SYMBOL(ir_raw_handler_register);
213 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
215 spin_lock(&ir_raw_handler_lock);
216 list_del(&ir_raw_handler->list);
217 spin_unlock(&ir_raw_handler_lock);
219 EXPORT_SYMBOL(ir_raw_handler_unregister);
221 static void init_decoders(struct work_struct *work)
223 /* Load the decoder modules */
228 /* If needed, we may later add some init code. In this case,
229 it is needed to change the CONFIG_MODULE test at ir-core.h
233 void ir_raw_init(void)
236 INIT_WORK(&wq_load, init_decoders);
237 schedule_work(&wq_load);