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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-20 12:37:45 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-20 12:37:45 -0400
commitfb091be08d1acf184e8801dfdcace6e0cb19b1fe (patch)
treecbd0c4200fd8628d592167589ca790e36fc4ae26 /drivers/media/IR/ir-rc5-decoder.c
parentbd7fc2f2d807fdb254f7efc542f8eec3f23e289e (diff)
parente8d0416796d43a950ec7b65629e53419b2e22453 (diff)
Merge branch 'v4l_for_2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
* 'v4l_for_2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (534 commits) V4L/DVB (13554a): v4l: Use the video_drvdata function in drivers V4L/DVB: vivi and mem2mem_testdev need slab.h to build V4L/DVB: tm6000: bugfix image position V4L/DVB: IR/imon: remove dead IMON_KEY_RELEASE_OFFSET V4L/DVB: tm6000: README - add vbi V4L/DVB: Fix unlock logic at medusa_video_init V4L/DVB: fix dvb frontend lockup V4L/DVB: s2255drv: remove dead code V4L/DVB: s2255drv: return if vdev not found V4L/DVB: ov511: cleanup: remove unneeded null check V4L/DVB: media/mem2mem: dereferencing free memory V4L/DVB: media/IR: Add missing include file to rc-map.c V4L/DVB: dvb/stv6110x: cleanup error handling V4L/DVB: ngene: Add lgdt3303 and mt2131 deps to Kconfig V4L/DVB: ngene: start separating out DVB functions into separate file V4L/DVB: ngene: split out card specific code into a separate file V4L/DVB: ngene: split out i2c code into a separate file V4L/DVB: ngene: add initial support for digital side of Avermedia m780 V4L/DVB: ngene: properly support boards where channel 0 isn't a TS input V4L-DVB: ngene: make sure that tuner headers are included ...
Diffstat (limited to 'drivers/media/IR/ir-rc5-decoder.c')
-rw-r--r--drivers/media/IR/ir-rc5-decoder.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c
new file mode 100644
index 000000000000..23cdb1b1a3bc
--- /dev/null
+++ b/drivers/media/IR/ir-rc5-decoder.c
@@ -0,0 +1,324 @@
1/* ir-rc5-decoder.c - handle RC5(x) IR Pulse/Space protocol
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/*
16 * This code handles 14 bits RC5 protocols and 20 bits RC5x protocols.
17 * There are other variants that use a different number of bits.
18 * This is currently unsupported.
19 * It considers a carrier of 36 kHz, with a total of 14/20 bits, where
20 * the first two bits are start bits, and a third one is a filing bit
21 */
22
23#include "ir-core-priv.h"
24
25#define RC5_NBITS 14
26#define RC5X_NBITS 20
27#define CHECK_RC5X_NBITS 8
28#define RC5_UNIT 888888 /* ns */
29#define RC5_BIT_START (1 * RC5_UNIT)
30#define RC5_BIT_END (1 * RC5_UNIT)
31#define RC5X_SPACE (4 * RC5_UNIT)
32
33/* Used to register rc5_decoder clients */
34static LIST_HEAD(decoder_list);
35static DEFINE_SPINLOCK(decoder_lock);
36
37enum rc5_state {
38 STATE_INACTIVE,
39 STATE_BIT_START,
40 STATE_BIT_END,
41 STATE_CHECK_RC5X,
42 STATE_FINISHED,
43};
44
45struct decoder_data {
46 struct list_head list;
47 struct ir_input_dev *ir_dev;
48 int enabled:1;
49
50 /* State machine control */
51 enum rc5_state state;
52 u32 rc5_bits;
53 struct ir_raw_event prev_ev;
54 unsigned count;
55 unsigned wanted_bits;
56};
57
58
59/**
60 * get_decoder_data() - gets decoder data
61 * @input_dev: input device
62 *
63 * Returns the struct decoder_data that corresponds to a device
64 */
65
66static struct decoder_data *get_decoder_data(struct ir_input_dev *ir_dev)
67{
68 struct decoder_data *data = NULL;
69
70 spin_lock(&decoder_lock);
71 list_for_each_entry(data, &decoder_list, list) {
72 if (data->ir_dev == ir_dev)
73 break;
74 }
75 spin_unlock(&decoder_lock);
76 return data;
77}
78
79static ssize_t store_enabled(struct device *d,
80 struct device_attribute *mattr,
81 const char *buf,
82 size_t len)
83{
84 unsigned long value;
85 struct ir_input_dev *ir_dev = dev_get_drvdata(d);
86 struct decoder_data *data = get_decoder_data(ir_dev);
87
88 if (!data)
89 return -EINVAL;
90
91 if (strict_strtoul(buf, 10, &value) || value > 1)
92 return -EINVAL;
93
94 data->enabled = value;
95
96 return len;
97}
98
99static ssize_t show_enabled(struct device *d,
100 struct device_attribute *mattr, char *buf)
101{
102 struct ir_input_dev *ir_dev = dev_get_drvdata(d);
103 struct decoder_data *data = get_decoder_data(ir_dev);
104
105 if (!data)
106 return -EINVAL;
107
108 if (data->enabled)
109 return sprintf(buf, "1\n");
110 else
111 return sprintf(buf, "0\n");
112}
113
114static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);
115
116static struct attribute *decoder_attributes[] = {
117 &dev_attr_enabled.attr,
118 NULL
119};
120
121static struct attribute_group decoder_attribute_group = {
122 .name = "rc5_decoder",
123 .attrs = decoder_attributes,
124};
125
126/**
127 * ir_rc5_decode() - Decode one RC-5 pulse or space
128 * @input_dev: the struct input_dev descriptor of the device
129 * @ev: the struct ir_raw_event descriptor of the pulse/space
130 *
131 * This function returns -EINVAL if the pulse violates the state machine
132 */
133static int ir_rc5_decode(struct input_dev *input_dev, struct ir_raw_event ev)
134{
135 struct decoder_data *data;
136 struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
137 u8 toggle;
138 u32 scancode;
139
140 data = get_decoder_data(ir_dev);
141 if (!data)
142 return -EINVAL;
143
144 if (!data->enabled)
145 return 0;
146
147 if (IS_RESET(ev)) {
148 data->state = STATE_INACTIVE;
149 return 0;
150 }
151
152 if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
153 goto out;
154
155again:
156 IR_dprintk(2, "RC5(x) decode started at state %i (%uus %s)\n",
157 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
158
159 if (!geq_margin(ev.duration, RC5_UNIT, RC5_UNIT / 2))
160 return 0;
161
162 switch (data->state) {
163
164 case STATE_INACTIVE:
165 if (!ev.pulse)
166 break;
167
168 data->state = STATE_BIT_START;
169 data->count = 1;
170 /* We just need enough bits to get to STATE_CHECK_RC5X */
171 data->wanted_bits = RC5X_NBITS;
172 decrease_duration(&ev, RC5_BIT_START);
173 goto again;
174
175 case STATE_BIT_START:
176 if (!eq_margin(ev.duration, RC5_BIT_START, RC5_UNIT / 2))
177 break;
178
179 data->rc5_bits <<= 1;
180 if (!ev.pulse)
181 data->rc5_bits |= 1;
182 data->count++;
183 data->prev_ev = ev;
184 data->state = STATE_BIT_END;
185 return 0;
186
187 case STATE_BIT_END:
188 if (!is_transition(&ev, &data->prev_ev))
189 break;
190
191 if (data->count == data->wanted_bits)
192 data->state = STATE_FINISHED;
193 else if (data->count == CHECK_RC5X_NBITS)
194 data->state = STATE_CHECK_RC5X;
195 else
196 data->state = STATE_BIT_START;
197
198 decrease_duration(&ev, RC5_BIT_END);
199 goto again;
200
201 case STATE_CHECK_RC5X:
202 if (!ev.pulse && geq_margin(ev.duration, RC5X_SPACE, RC5_UNIT / 2)) {
203 /* RC5X */
204 data->wanted_bits = RC5X_NBITS;
205 decrease_duration(&ev, RC5X_SPACE);
206 } else {
207 /* RC5 */
208 data->wanted_bits = RC5_NBITS;
209 }
210 data->state = STATE_BIT_START;
211 goto again;
212
213 case STATE_FINISHED:
214 if (ev.pulse)
215 break;
216
217 if (data->wanted_bits == RC5X_NBITS) {
218 /* RC5X */
219 u8 xdata, command, system;
220 xdata = (data->rc5_bits & 0x0003F) >> 0;
221 command = (data->rc5_bits & 0x00FC0) >> 6;
222 system = (data->rc5_bits & 0x1F000) >> 12;
223 toggle = (data->rc5_bits & 0x20000) ? 1 : 0;
224 command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
225 scancode = system << 16 | command << 8 | xdata;
226
227 IR_dprintk(1, "RC5X scancode 0x%06x (toggle: %u)\n",
228 scancode, toggle);
229
230 } else {
231 /* RC5 */
232 u8 command, system;
233 command = (data->rc5_bits & 0x0003F) >> 0;
234 system = (data->rc5_bits & 0x007C0) >> 6;
235 toggle = (data->rc5_bits & 0x00800) ? 1 : 0;
236 command += (data->rc5_bits & 0x01000) ? 0 : 0x40;
237 scancode = system << 8 | command;
238
239 IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n",
240 scancode, toggle);
241 }
242
243 ir_keydown(input_dev, scancode, toggle);
244 data->state = STATE_INACTIVE;
245 return 0;
246 }
247
248out:
249 IR_dprintk(1, "RC5(x) decode failed at state %i (%uus %s)\n",
250 data->state, TO_US(ev.duration), TO_STR(ev.pulse));
251 data->state = STATE_INACTIVE;
252 return -EINVAL;
253}
254
255static int ir_rc5_register(struct input_dev *input_dev)
256{
257 struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
258 struct decoder_data *data;
259 int rc;
260
261 rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
262 if (rc < 0)
263 return rc;
264
265 data = kzalloc(sizeof(*data), GFP_KERNEL);
266 if (!data) {
267 sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
268 return -ENOMEM;
269 }
270
271 data->ir_dev = ir_dev;
272 data->enabled = 1;
273
274 spin_lock(&decoder_lock);
275 list_add_tail(&data->list, &decoder_list);
276 spin_unlock(&decoder_lock);
277
278 return 0;
279}
280
281static int ir_rc5_unregister(struct input_dev *input_dev)
282{
283 struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
284 static struct decoder_data *data;
285
286 data = get_decoder_data(ir_dev);
287 if (!data)
288 return 0;
289
290 sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
291
292 spin_lock(&decoder_lock);
293 list_del(&data->list);
294 spin_unlock(&decoder_lock);
295
296 return 0;
297}
298
299static struct ir_raw_handler rc5_handler = {
300 .decode = ir_rc5_decode,
301 .raw_register = ir_rc5_register,
302 .raw_unregister = ir_rc5_unregister,
303};
304
305static int __init ir_rc5_decode_init(void)
306{
307 ir_raw_handler_register(&rc5_handler);
308
309 printk(KERN_INFO "IR RC5(x) protocol handler initialized\n");
310 return 0;
311}
312
313static void __exit ir_rc5_decode_exit(void)
314{
315 ir_raw_handler_unregister(&rc5_handler);
316}
317
318module_init(ir_rc5_decode_init);
319module_exit(ir_rc5_decode_exit);
320
321MODULE_LICENSE("GPL");
322MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
323MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
324MODULE_DESCRIPTION("RC5(x) IR protocol decoder");