1 /* ir-raw.c - handle IR pulse/space events
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/export.h>
16 #include <linux/kthread.h>
17 #include <linux/mutex.h>
18 #include <linux/kmod.h>
19 #include <linux/sched.h>
20 #include <linux/freezer.h>
21 #include "rc-core-priv.h"
23 /* Define the max number of pulse/space transitions to buffer */
24 #define MAX_IR_EVENT_SIZE 512
26 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
27 static LIST_HEAD(ir_raw_client_list);
29 /* Used to handle IR raw handler extensions */
30 static DEFINE_MUTEX(ir_raw_handler_lock);
31 static LIST_HEAD(ir_raw_handler_list);
32 static u64 available_protocols;
35 /* Used to load the decoders */
36 static struct work_struct wq_load;
39 static int ir_raw_event_thread(void *data)
41 struct ir_raw_event ev;
42 struct ir_raw_handler *handler;
43 struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
46 while (!kthread_should_stop()) {
48 spin_lock_irq(&raw->lock);
49 retval = kfifo_len(&raw->kfifo);
51 if (retval < sizeof(ev)) {
52 set_current_state(TASK_INTERRUPTIBLE);
54 if (kthread_should_stop())
55 set_current_state(TASK_RUNNING);
57 spin_unlock_irq(&raw->lock);
62 retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
63 spin_unlock_irq(&raw->lock);
65 mutex_lock(&ir_raw_handler_lock);
66 list_for_each_entry(handler, &ir_raw_handler_list, list)
67 handler->decode(raw->dev, ev);
69 mutex_unlock(&ir_raw_handler_lock);
76 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
77 * @dev: the struct rc_dev device descriptor
78 * @ev: the struct ir_raw_event descriptor of the pulse/space
80 * This routine (which may be called from an interrupt context) stores a
81 * pulse/space duration for the raw ir decoding state machines. Pulses are
82 * signalled as positive values and spaces as negative values. A zero value
83 * will reset the decoding state machines.
85 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
90 IR_dprintk(2, "sample: (%05dus %s)\n",
91 TO_US(ev->duration), TO_STR(ev->pulse));
93 if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
98 EXPORT_SYMBOL_GPL(ir_raw_event_store);
101 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
102 * @dev: the struct rc_dev device descriptor
103 * @type: the type of the event that has occurred
105 * This routine (which may be called from an interrupt context) is used to
106 * store the beginning of an ir pulse or space (or the start/end of ir
107 * reception) for the raw ir decoding state machines. This is used by
108 * hardware which does not provide durations directly but only interrupts
109 * (or similar events) on state change.
111 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
115 DEFINE_IR_RAW_EVENT(ev);
123 delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
124 delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
126 /* Check for a long duration since last event or if we're
127 * being called for the first time, note that delta can't
128 * possibly be negative.
130 if (delta > delay || !dev->raw->last_type)
131 type |= IR_START_EVENT;
135 if (type & IR_START_EVENT)
136 ir_raw_event_reset(dev);
137 else if (dev->raw->last_type & IR_SPACE) {
139 rc = ir_raw_event_store(dev, &ev);
140 } else if (dev->raw->last_type & IR_PULSE) {
142 rc = ir_raw_event_store(dev, &ev);
146 dev->raw->last_event = now;
147 dev->raw->last_type = type;
150 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
153 * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
154 * @dev: the struct rc_dev device descriptor
155 * @type: the type of the event that has occurred
157 * This routine (which may be called from an interrupt context) works
158 * in similar manner to ir_raw_event_store_edge.
159 * This routine is intended for devices with limited internal buffer
160 * It automerges samples of same type, and handles timeouts. Returns non-zero
161 * if the event was added, and zero if the event was ignored due to idle
164 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
169 /* Ignore spaces in idle mode */
170 if (dev->idle && !ev->pulse)
173 ir_raw_event_set_idle(dev, false);
175 if (!dev->raw->this_ev.duration)
176 dev->raw->this_ev = *ev;
177 else if (ev->pulse == dev->raw->this_ev.pulse)
178 dev->raw->this_ev.duration += ev->duration;
180 ir_raw_event_store(dev, &dev->raw->this_ev);
181 dev->raw->this_ev = *ev;
184 /* Enter idle mode if nessesary */
185 if (!ev->pulse && dev->timeout &&
186 dev->raw->this_ev.duration >= dev->timeout)
187 ir_raw_event_set_idle(dev, true);
191 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
194 * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
195 * @dev: the struct rc_dev device descriptor
196 * @idle: whether the device is idle or not
198 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
203 IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
206 dev->raw->this_ev.timeout = true;
207 ir_raw_event_store(dev, &dev->raw->this_ev);
208 init_ir_raw_event(&dev->raw->this_ev);
212 dev->s_idle(dev, idle);
216 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
219 * ir_raw_event_handle() - schedules the decoding of stored ir data
220 * @dev: the struct rc_dev device descriptor
222 * This routine will tell rc-core to start decoding stored ir data.
224 void ir_raw_event_handle(struct rc_dev *dev)
231 spin_lock_irqsave(&dev->raw->lock, flags);
232 wake_up_process(dev->raw->thread);
233 spin_unlock_irqrestore(&dev->raw->lock, flags);
235 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
237 /* used internally by the sysfs interface */
239 ir_raw_get_allowed_protocols(void)
242 mutex_lock(&ir_raw_handler_lock);
243 protocols = available_protocols;
244 mutex_unlock(&ir_raw_handler_lock);
249 * Used to (un)register raw event clients
251 int ir_raw_event_register(struct rc_dev *dev)
254 struct ir_raw_handler *handler;
259 dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
264 dev->raw->enabled_protocols = ~0;
265 rc = kfifo_alloc(&dev->raw->kfifo,
266 sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
271 spin_lock_init(&dev->raw->lock);
272 dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
273 "rc%ld", dev->devno);
275 if (IS_ERR(dev->raw->thread)) {
276 rc = PTR_ERR(dev->raw->thread);
280 mutex_lock(&ir_raw_handler_lock);
281 list_add_tail(&dev->raw->list, &ir_raw_client_list);
282 list_for_each_entry(handler, &ir_raw_handler_list, list)
283 if (handler->raw_register)
284 handler->raw_register(dev);
285 mutex_unlock(&ir_raw_handler_lock);
295 void ir_raw_event_unregister(struct rc_dev *dev)
297 struct ir_raw_handler *handler;
299 if (!dev || !dev->raw)
302 kthread_stop(dev->raw->thread);
304 mutex_lock(&ir_raw_handler_lock);
305 list_del(&dev->raw->list);
306 list_for_each_entry(handler, &ir_raw_handler_list, list)
307 if (handler->raw_unregister)
308 handler->raw_unregister(dev);
309 mutex_unlock(&ir_raw_handler_lock);
311 kfifo_free(&dev->raw->kfifo);
317 * Extension interface - used to register the IR decoders
320 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
322 struct ir_raw_event_ctrl *raw;
324 mutex_lock(&ir_raw_handler_lock);
325 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
326 if (ir_raw_handler->raw_register)
327 list_for_each_entry(raw, &ir_raw_client_list, list)
328 ir_raw_handler->raw_register(raw->dev);
329 available_protocols |= ir_raw_handler->protocols;
330 mutex_unlock(&ir_raw_handler_lock);
334 EXPORT_SYMBOL(ir_raw_handler_register);
336 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
338 struct ir_raw_event_ctrl *raw;
340 mutex_lock(&ir_raw_handler_lock);
341 list_del(&ir_raw_handler->list);
342 if (ir_raw_handler->raw_unregister)
343 list_for_each_entry(raw, &ir_raw_client_list, list)
344 ir_raw_handler->raw_unregister(raw->dev);
345 available_protocols &= ~ir_raw_handler->protocols;
346 mutex_unlock(&ir_raw_handler_lock);
348 EXPORT_SYMBOL(ir_raw_handler_unregister);
351 static void init_decoders(struct work_struct *work)
353 /* Load the decoder modules */
361 load_mce_kbd_decode();
364 /* If needed, we may later add some init code. In this case,
365 it is needed to change the CONFIG_MODULE test at rc-core.h
370 void ir_raw_init(void)
373 INIT_WORK(&wq_load, init_decoders);
374 schedule_work(&wq_load);