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1 /* ir-raw.c - handle IR pulse/space events
2  *
3  * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
4  *
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.
8  *
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.
13  */
14 
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"
22 
23 /* Define the max number of pulse/space transitions to buffer */
24 #define MAX_IR_EVENT_SIZE      512
25 
26 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
27 static LIST_HEAD(ir_raw_client_list);
28 
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;
33 
ir_raw_event_thread(void * data)34 static int ir_raw_event_thread(void *data)
35 {
36 	struct ir_raw_event ev;
37 	struct ir_raw_handler *handler;
38 	struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
39 	int retval;
40 
41 	while (!kthread_should_stop()) {
42 
43 		spin_lock_irq(&raw->lock);
44 		retval = kfifo_len(&raw->kfifo);
45 
46 		if (retval < sizeof(ev)) {
47 			set_current_state(TASK_INTERRUPTIBLE);
48 
49 			if (kthread_should_stop())
50 				set_current_state(TASK_RUNNING);
51 
52 			spin_unlock_irq(&raw->lock);
53 			schedule();
54 			continue;
55 		}
56 
57 		retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
58 		spin_unlock_irq(&raw->lock);
59 
60 		mutex_lock(&ir_raw_handler_lock);
61 		list_for_each_entry(handler, &ir_raw_handler_list, list)
62 			handler->decode(raw->dev, ev);
63 		raw->prev_ev = ev;
64 		mutex_unlock(&ir_raw_handler_lock);
65 	}
66 
67 	return 0;
68 }
69 
70 /**
71  * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
72  * @dev:	the struct rc_dev device descriptor
73  * @ev:		the struct ir_raw_event descriptor of the pulse/space
74  *
75  * This routine (which may be called from an interrupt context) stores a
76  * pulse/space duration for the raw ir decoding state machines. Pulses are
77  * signalled as positive values and spaces as negative values. A zero value
78  * will reset the decoding state machines.
79  */
ir_raw_event_store(struct rc_dev * dev,struct ir_raw_event * ev)80 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
81 {
82 	if (!dev->raw)
83 		return -EINVAL;
84 
85 	IR_dprintk(2, "sample: (%05dus %s)\n",
86 		   TO_US(ev->duration), TO_STR(ev->pulse));
87 
88 	if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
89 		return -ENOMEM;
90 
91 	return 0;
92 }
93 EXPORT_SYMBOL_GPL(ir_raw_event_store);
94 
95 /**
96  * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
97  * @dev:	the struct rc_dev device descriptor
98  * @type:	the type of the event that has occurred
99  *
100  * This routine (which may be called from an interrupt context) is used to
101  * store the beginning of an ir pulse or space (or the start/end of ir
102  * reception) for the raw ir decoding state machines. This is used by
103  * hardware which does not provide durations directly but only interrupts
104  * (or similar events) on state change.
105  */
ir_raw_event_store_edge(struct rc_dev * dev,enum raw_event_type type)106 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
107 {
108 	ktime_t			now;
109 	s64			delta; /* ns */
110 	DEFINE_IR_RAW_EVENT(ev);
111 	int			rc = 0;
112 	int			delay;
113 
114 	if (!dev->raw)
115 		return -EINVAL;
116 
117 	now = ktime_get();
118 	delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
119 	delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
120 
121 	/* Check for a long duration since last event or if we're
122 	 * being called for the first time, note that delta can't
123 	 * possibly be negative.
124 	 */
125 	if (delta > delay || !dev->raw->last_type)
126 		type |= IR_START_EVENT;
127 	else
128 		ev.duration = delta;
129 
130 	if (type & IR_START_EVENT)
131 		ir_raw_event_reset(dev);
132 	else if (dev->raw->last_type & IR_SPACE) {
133 		ev.pulse = false;
134 		rc = ir_raw_event_store(dev, &ev);
135 	} else if (dev->raw->last_type & IR_PULSE) {
136 		ev.pulse = true;
137 		rc = ir_raw_event_store(dev, &ev);
138 	} else
139 		return 0;
140 
141 	dev->raw->last_event = now;
142 	dev->raw->last_type = type;
143 	return rc;
144 }
145 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
146 
147 /**
148  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
149  * @dev:	the struct rc_dev device descriptor
150  * @type:	the type of the event that has occurred
151  *
152  * This routine (which may be called from an interrupt context) works
153  * in similar manner to ir_raw_event_store_edge.
154  * This routine is intended for devices with limited internal buffer
155  * It automerges samples of same type, and handles timeouts. Returns non-zero
156  * if the event was added, and zero if the event was ignored due to idle
157  * processing.
158  */
ir_raw_event_store_with_filter(struct rc_dev * dev,struct ir_raw_event * ev)159 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
160 {
161 	if (!dev->raw)
162 		return -EINVAL;
163 
164 	/* Ignore spaces in idle mode */
165 	if (dev->idle && !ev->pulse)
166 		return 0;
167 	else if (dev->idle)
168 		ir_raw_event_set_idle(dev, false);
169 
170 	if (!dev->raw->this_ev.duration)
171 		dev->raw->this_ev = *ev;
172 	else if (ev->pulse == dev->raw->this_ev.pulse)
173 		dev->raw->this_ev.duration += ev->duration;
174 	else {
175 		ir_raw_event_store(dev, &dev->raw->this_ev);
176 		dev->raw->this_ev = *ev;
177 	}
178 
179 	/* Enter idle mode if nessesary */
180 	if (!ev->pulse && dev->timeout &&
181 	    dev->raw->this_ev.duration >= dev->timeout)
182 		ir_raw_event_set_idle(dev, true);
183 
184 	return 1;
185 }
186 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
187 
188 /**
189  * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
190  * @dev:	the struct rc_dev device descriptor
191  * @idle:	whether the device is idle or not
192  */
ir_raw_event_set_idle(struct rc_dev * dev,bool idle)193 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
194 {
195 	if (!dev->raw)
196 		return;
197 
198 	IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
199 
200 	if (idle) {
201 		dev->raw->this_ev.timeout = true;
202 		ir_raw_event_store(dev, &dev->raw->this_ev);
203 		init_ir_raw_event(&dev->raw->this_ev);
204 	}
205 
206 	if (dev->s_idle)
207 		dev->s_idle(dev, idle);
208 
209 	dev->idle = idle;
210 }
211 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
212 
213 /**
214  * ir_raw_event_handle() - schedules the decoding of stored ir data
215  * @dev:	the struct rc_dev device descriptor
216  *
217  * This routine will tell rc-core to start decoding stored ir data.
218  */
ir_raw_event_handle(struct rc_dev * dev)219 void ir_raw_event_handle(struct rc_dev *dev)
220 {
221 	unsigned long flags;
222 
223 	if (!dev->raw)
224 		return;
225 
226 	spin_lock_irqsave(&dev->raw->lock, flags);
227 	wake_up_process(dev->raw->thread);
228 	spin_unlock_irqrestore(&dev->raw->lock, flags);
229 }
230 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
231 
232 /* used internally by the sysfs interface */
233 u64
ir_raw_get_allowed_protocols(void)234 ir_raw_get_allowed_protocols(void)
235 {
236 	u64 protocols;
237 	mutex_lock(&ir_raw_handler_lock);
238 	protocols = available_protocols;
239 	mutex_unlock(&ir_raw_handler_lock);
240 	return protocols;
241 }
242 
243 /*
244  * Used to (un)register raw event clients
245  */
ir_raw_event_register(struct rc_dev * dev)246 int ir_raw_event_register(struct rc_dev *dev)
247 {
248 	int rc;
249 	struct ir_raw_handler *handler;
250 
251 	if (!dev)
252 		return -EINVAL;
253 
254 	dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
255 	if (!dev->raw)
256 		return -ENOMEM;
257 
258 	dev->raw->dev = dev;
259 	dev->enabled_protocols = ~0;
260 	rc = kfifo_alloc(&dev->raw->kfifo,
261 			 sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
262 			 GFP_KERNEL);
263 	if (rc < 0)
264 		goto out;
265 
266 	spin_lock_init(&dev->raw->lock);
267 	dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
268 				       "rc%ld", dev->devno);
269 
270 	if (IS_ERR(dev->raw->thread)) {
271 		rc = PTR_ERR(dev->raw->thread);
272 		goto out;
273 	}
274 
275 	mutex_lock(&ir_raw_handler_lock);
276 	list_add_tail(&dev->raw->list, &ir_raw_client_list);
277 	list_for_each_entry(handler, &ir_raw_handler_list, list)
278 		if (handler->raw_register)
279 			handler->raw_register(dev);
280 	mutex_unlock(&ir_raw_handler_lock);
281 
282 	return 0;
283 
284 out:
285 	kfree(dev->raw);
286 	dev->raw = NULL;
287 	return rc;
288 }
289 
ir_raw_event_unregister(struct rc_dev * dev)290 void ir_raw_event_unregister(struct rc_dev *dev)
291 {
292 	struct ir_raw_handler *handler;
293 
294 	if (!dev || !dev->raw)
295 		return;
296 
297 	kthread_stop(dev->raw->thread);
298 
299 	mutex_lock(&ir_raw_handler_lock);
300 	list_del(&dev->raw->list);
301 	list_for_each_entry(handler, &ir_raw_handler_list, list)
302 		if (handler->raw_unregister)
303 			handler->raw_unregister(dev);
304 	mutex_unlock(&ir_raw_handler_lock);
305 
306 	kfifo_free(&dev->raw->kfifo);
307 	kfree(dev->raw);
308 	dev->raw = NULL;
309 }
310 
311 /*
312  * Extension interface - used to register the IR decoders
313  */
314 
ir_raw_handler_register(struct ir_raw_handler * ir_raw_handler)315 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
316 {
317 	struct ir_raw_event_ctrl *raw;
318 
319 	mutex_lock(&ir_raw_handler_lock);
320 	list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
321 	if (ir_raw_handler->raw_register)
322 		list_for_each_entry(raw, &ir_raw_client_list, list)
323 			ir_raw_handler->raw_register(raw->dev);
324 	available_protocols |= ir_raw_handler->protocols;
325 	mutex_unlock(&ir_raw_handler_lock);
326 
327 	return 0;
328 }
329 EXPORT_SYMBOL(ir_raw_handler_register);
330 
ir_raw_handler_unregister(struct ir_raw_handler * ir_raw_handler)331 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
332 {
333 	struct ir_raw_event_ctrl *raw;
334 
335 	mutex_lock(&ir_raw_handler_lock);
336 	list_del(&ir_raw_handler->list);
337 	if (ir_raw_handler->raw_unregister)
338 		list_for_each_entry(raw, &ir_raw_client_list, list)
339 			ir_raw_handler->raw_unregister(raw->dev);
340 	available_protocols &= ~ir_raw_handler->protocols;
341 	mutex_unlock(&ir_raw_handler_lock);
342 }
343 EXPORT_SYMBOL(ir_raw_handler_unregister);
344 
ir_raw_init(void)345 void ir_raw_init(void)
346 {
347 	/* Load the decoder modules */
348 
349 	load_nec_decode();
350 	load_rc5_decode();
351 	load_rc6_decode();
352 	load_jvc_decode();
353 	load_sony_decode();
354 	load_sanyo_decode();
355 	load_mce_kbd_decode();
356 	load_lirc_codec();
357 
358 	/* If needed, we may later add some init code. In this case,
359 	   it is needed to change the CONFIG_MODULE test at rc-core.h
360 	 */
361 }
362