Commit | Line | Data |
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995187be | 1 | /* ir-nec-decoder.c - handle NEC IR Pulse/Space protocol |
a3572c34 MCC |
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 <media/ir-core.h> | |
16 | ||
2f16f631 MCC |
17 | #define NEC_UNIT 559979 /* ns */ |
18 | #define NEC_HEADER_MARK (16 * NEC_UNIT) | |
19 | #define NEC_HEADER_SPACE (8 * NEC_UNIT) | |
20 | #define NEC_REPEAT_SPACE (4 * NEC_UNIT) | |
21 | #define NEC_MARK (NEC_UNIT) | |
22 | #define NEC_0_SYMBOL (NEC_UNIT) | |
23 | #define NEC_1_SYMBOL (3 * NEC_UNIT) | |
24 | ||
9f154782 MCC |
25 | /* Start time: 4.5 ms + 560 us of the next pulse */ |
26 | #define MIN_START_TIME (3900000 + 560000) | |
27 | #define MAX_START_TIME (5100000 + 560000) | |
a3572c34 | 28 | |
9f154782 MCC |
29 | /* Bit 1 time: 2.25ms us */ |
30 | #define MIN_BIT1_TIME 2050000 | |
31 | #define MAX_BIT1_TIME 2450000 | |
a3572c34 | 32 | |
9f154782 MCC |
33 | /* Bit 0 time: 1.12ms us */ |
34 | #define MIN_BIT0_TIME 920000 | |
35 | #define MAX_BIT0_TIME 1320000 | |
a3572c34 | 36 | |
9f154782 MCC |
37 | /* Total IR code is 110 ms, including the 9 ms for the start pulse */ |
38 | #define MAX_NEC_TIME 4000000 | |
39 | ||
40 | /* Total IR code is 110 ms, including the 9 ms for the start pulse */ | |
41 | #define MIN_REPEAT_TIME 99000000 | |
42 | #define MAX_REPEAT_TIME 112000000 | |
43 | ||
44 | /* Repeat time: 2.25ms us */ | |
45 | #define MIN_REPEAT_START_TIME 2050000 | |
46 | #define MAX_REPEAT_START_TIME 3000000 | |
47 | ||
48 | #define REPEAT_TIME 240 /* ms */ | |
49 | ||
20d5f116 MCC |
50 | /* Used to register nec_decoder clients */ |
51 | static LIST_HEAD(decoder_list); | |
52 | static spinlock_t decoder_lock; | |
53 | ||
2f16f631 MCC |
54 | enum nec_state { |
55 | STATE_INACTIVE, | |
56 | STATE_HEADER_MARK, | |
57 | STATE_HEADER_SPACE, | |
58 | STATE_MARK, | |
59 | STATE_SPACE, | |
60 | STATE_TRAILER_MARK, | |
61 | STATE_TRAILER_SPACE, | |
62 | }; | |
63 | ||
64 | struct nec_code { | |
65 | u8 address; | |
66 | u8 not_address; | |
67 | u8 command; | |
68 | u8 not_command; | |
69 | }; | |
70 | ||
20d5f116 MCC |
71 | struct decoder_data { |
72 | struct list_head list; | |
73 | struct ir_input_dev *ir_dev; | |
74 | int enabled:1; | |
2f16f631 MCC |
75 | |
76 | /* State machine control */ | |
77 | enum nec_state state; | |
78 | struct nec_code nec_code; | |
79 | unsigned count; | |
20d5f116 MCC |
80 | }; |
81 | ||
82 | ||
83 | /** | |
84 | * get_decoder_data() - gets decoder data | |
85 | * @input_dev: input device | |
86 | * | |
87 | * Returns the struct decoder_data that corresponds to a device | |
88 | */ | |
89 | ||
90 | static struct decoder_data *get_decoder_data(struct ir_input_dev *ir_dev) | |
91 | { | |
92 | struct decoder_data *data = NULL; | |
93 | ||
94 | spin_lock(&decoder_lock); | |
95 | list_for_each_entry(data, &decoder_list, list) { | |
96 | if (data->ir_dev == ir_dev) | |
97 | break; | |
98 | } | |
99 | spin_unlock(&decoder_lock); | |
100 | return data; | |
101 | } | |
102 | ||
103 | static ssize_t store_enabled(struct device *d, | |
104 | struct device_attribute *mattr, | |
105 | const char *buf, | |
106 | size_t len) | |
107 | { | |
108 | unsigned long value; | |
109 | struct ir_input_dev *ir_dev = dev_get_drvdata(d); | |
110 | struct decoder_data *data = get_decoder_data(ir_dev); | |
111 | ||
112 | if (!data) | |
113 | return -EINVAL; | |
114 | ||
115 | if (strict_strtoul(buf, 10, &value) || value > 1) | |
116 | return -EINVAL; | |
117 | ||
118 | data->enabled = value; | |
119 | ||
120 | return len; | |
121 | } | |
122 | ||
123 | static ssize_t show_enabled(struct device *d, | |
124 | struct device_attribute *mattr, char *buf) | |
125 | { | |
126 | struct ir_input_dev *ir_dev = dev_get_drvdata(d); | |
127 | struct decoder_data *data = get_decoder_data(ir_dev); | |
128 | ||
129 | if (!data) | |
130 | return -EINVAL; | |
131 | ||
132 | if (data->enabled) | |
133 | return sprintf(buf, "1\n"); | |
134 | else | |
135 | return sprintf(buf, "0\n"); | |
136 | } | |
137 | ||
138 | static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled); | |
139 | ||
140 | static struct attribute *decoder_attributes[] = { | |
141 | &dev_attr_enabled.attr, | |
142 | NULL | |
143 | }; | |
144 | ||
145 | static struct attribute_group decoder_attribute_group = { | |
146 | .name = "nec_decoder", | |
147 | .attrs = decoder_attributes, | |
148 | }; | |
149 | ||
150 | ||
2f16f631 MCC |
151 | /** |
152 | * handle_event() - Decode one NEC pulse or space | |
9f154782 | 153 | * @input_dev: the struct input_dev descriptor of the device |
2f16f631 MCC |
154 | * @ev: event array with type/duration of pulse/space |
155 | * | |
156 | * This function returns -EINVAL if the pulse violates the state machine | |
9f154782 | 157 | */ |
2f16f631 MCC |
158 | static int handle_event(struct input_dev *input_dev, |
159 | struct ir_raw_event *ev) | |
9f154782 | 160 | { |
2f16f631 MCC |
161 | struct decoder_data *data; |
162 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); | |
163 | int bit, last_bit; | |
9f154782 | 164 | |
2f16f631 MCC |
165 | data = get_decoder_data(ir_dev); |
166 | if (!data) | |
167 | return -EINVAL; | |
9f154782 | 168 | |
2f16f631 MCC |
169 | /* Except for the initial event, what matters is the previous bit */ |
170 | bit = (ev->type & IR_PULSE) ? 1 : 0; | |
9f154782 | 171 | |
2f16f631 | 172 | last_bit = !bit; |
a3572c34 | 173 | |
2f16f631 | 174 | /* Discards spurious space last_bits when inactive */ |
a3572c34 | 175 | |
2f16f631 MCC |
176 | /* Very long delays are considered as start events */ |
177 | if (ev->delta.tv_nsec > NEC_HEADER_MARK + NEC_HEADER_SPACE - NEC_UNIT / 2) | |
178 | data->state = STATE_INACTIVE; | |
a3572c34 | 179 | |
2f16f631 MCC |
180 | if (ev->type & IR_START_EVENT) |
181 | data->state = STATE_INACTIVE; | |
9f154782 | 182 | |
2f16f631 MCC |
183 | switch (data->state) { |
184 | case STATE_INACTIVE: | |
185 | if (!bit) /* PULSE marks the start event */ | |
186 | return 0; | |
a3572c34 | 187 | |
2f16f631 MCC |
188 | data->count = 0; |
189 | data->state = STATE_HEADER_MARK; | |
190 | memset (&data->nec_code, 0, sizeof(data->nec_code)); | |
191 | return 0; | |
192 | case STATE_HEADER_MARK: | |
193 | if (!last_bit) | |
194 | goto err; | |
195 | if (ev->delta.tv_nsec < NEC_HEADER_MARK - 6 * NEC_UNIT) | |
196 | goto err; | |
197 | data->state = STATE_HEADER_SPACE; | |
198 | return 0; | |
199 | case STATE_HEADER_SPACE: | |
200 | if (last_bit) | |
201 | goto err; | |
202 | if (ev->delta.tv_nsec >= NEC_HEADER_SPACE - NEC_UNIT / 2) { | |
203 | data->state = STATE_MARK; | |
9f154782 MCC |
204 | return 0; |
205 | } | |
9f154782 | 206 | |
2f16f631 MCC |
207 | if (ev->delta.tv_nsec >= NEC_REPEAT_SPACE - NEC_UNIT / 2) { |
208 | ir_repeat(input_dev); | |
209 | IR_dprintk(1, "Repeat last key\n"); | |
210 | data->state = STATE_TRAILER_MARK; | |
211 | return 0; | |
212 | } | |
9f154782 | 213 | goto err; |
2f16f631 MCC |
214 | case STATE_MARK: |
215 | if (!last_bit) | |
216 | goto err; | |
217 | if ((ev->delta.tv_nsec > NEC_MARK + NEC_UNIT / 2) || | |
218 | (ev->delta.tv_nsec < NEC_MARK - NEC_UNIT / 2)) | |
219 | goto err; | |
220 | data->state = STATE_SPACE; | |
221 | return 0; | |
222 | case STATE_SPACE: | |
223 | if (last_bit) | |
224 | goto err; | |
a3572c34 | 225 | |
2f16f631 MCC |
226 | if ((ev->delta.tv_nsec >= NEC_0_SYMBOL - NEC_UNIT / 2) && |
227 | (ev->delta.tv_nsec < NEC_0_SYMBOL + NEC_UNIT / 2)) | |
a3572c34 | 228 | bit = 0; |
2f16f631 MCC |
229 | else if ((ev->delta.tv_nsec >= NEC_1_SYMBOL - NEC_UNIT / 2) && |
230 | (ev->delta.tv_nsec < NEC_1_SYMBOL + NEC_UNIT / 2)) | |
231 | bit = 1; | |
232 | else { | |
233 | IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n", | |
234 | data->count, | |
235 | last_bit ? "pulse" : "space", | |
236 | (ev->delta.tv_nsec + 500) / 1000); | |
237 | ||
238 | goto err2; | |
239 | } | |
a3572c34 | 240 | |
2f16f631 | 241 | /* Ok, we've got a valid bit. proccess it */ |
a3572c34 | 242 | if (bit) { |
2f16f631 MCC |
243 | int shift = data->count; |
244 | ||
245 | /* | |
246 | * NEC transmit bytes on this temporal order: | |
247 | * address | not address | command | not command | |
248 | */ | |
a3572c34 | 249 | if (shift < 8) { |
2f16f631 | 250 | data->nec_code.address |= 1 << shift; |
a3572c34 | 251 | } else if (shift < 16) { |
2f16f631 | 252 | data->nec_code.not_address |= 1 << (shift - 8); |
a3572c34 | 253 | } else if (shift < 24) { |
2f16f631 | 254 | data->nec_code.command |= 1 << (shift - 16); |
a3572c34 | 255 | } else { |
2f16f631 | 256 | data->nec_code.not_command |= 1 << (shift - 24); |
a3572c34 MCC |
257 | } |
258 | } | |
2f16f631 MCC |
259 | if (++data->count == 32) { |
260 | u32 scancode; | |
261 | /* | |
262 | * Fixme: may need to accept Extended NEC protocol? | |
263 | */ | |
264 | if ((data->nec_code.command ^ data->nec_code.not_command) != 0xff) | |
265 | goto checksum_err; | |
266 | ||
267 | if ((data->nec_code.address ^ data->nec_code.not_address) != 0xff) { | |
268 | /* Extended NEC */ | |
269 | scancode = data->nec_code.address << 16 | | |
270 | data->nec_code.not_address << 8 | | |
271 | data->nec_code.command; | |
272 | IR_dprintk(1, "NEC scancode 0x%06x\n", scancode); | |
273 | } else { | |
274 | /* normal NEC */ | |
275 | scancode = data->nec_code.address << 8 | | |
276 | data->nec_code.command; | |
277 | IR_dprintk(1, "NEC scancode 0x%04x\n", scancode); | |
278 | } | |
279 | ir_keydown(input_dev, scancode, 0); | |
a3572c34 | 280 | |
2f16f631 MCC |
281 | data->state = STATE_TRAILER_MARK; |
282 | } else | |
283 | data->state = STATE_MARK; | |
284 | return 0; | |
285 | case STATE_TRAILER_MARK: | |
286 | if (!last_bit) | |
287 | goto err; | |
288 | data->state = STATE_TRAILER_SPACE; | |
289 | return 0; | |
290 | case STATE_TRAILER_SPACE: | |
291 | if (last_bit) | |
292 | goto err; | |
293 | data->state = STATE_INACTIVE; | |
294 | return 0; | |
295 | } | |
a3572c34 | 296 | |
a3572c34 | 297 | err: |
2f16f631 MCC |
298 | IR_dprintk(1, "NEC decoded failed at state %d (%s) @ %luus\n", |
299 | data->state, | |
300 | bit ? "pulse" : "space", | |
301 | (ev->delta.tv_nsec + 500) / 1000); | |
302 | err2: | |
303 | data->state = STATE_INACTIVE; | |
304 | return -EINVAL; | |
a3572c34 | 305 | |
2f16f631 MCC |
306 | checksum_err: |
307 | data->state = STATE_INACTIVE; | |
308 | IR_dprintk(1, "NEC checksum error: received 0x%02x%02x%02x%02x\n", | |
309 | data->nec_code.address, | |
310 | data->nec_code.not_address, | |
311 | data->nec_code.command, | |
312 | data->nec_code.not_command); | |
a3572c34 MCC |
313 | return -EINVAL; |
314 | } | |
ada39630 MCC |
315 | |
316 | /** | |
2f16f631 | 317 | * ir_nec_decode() - Decodes all NEC pulsecodes on a given array |
ada39630 MCC |
318 | * @input_dev: the struct input_dev descriptor of the device |
319 | * @evs: event array with type/duration of pulse/space | |
320 | * @len: length of the array | |
93c312ff | 321 | * This function returns the number of decoded pulses |
ada39630 | 322 | */ |
995187be MCC |
323 | static int ir_nec_decode(struct input_dev *input_dev, |
324 | struct ir_raw_event *evs, | |
325 | int len) | |
ada39630 | 326 | { |
20d5f116 MCC |
327 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); |
328 | struct decoder_data *data; | |
ada39630 MCC |
329 | int pos = 0; |
330 | int rc = 0; | |
331 | ||
20d5f116 MCC |
332 | data = get_decoder_data(ir_dev); |
333 | if (!data || !data->enabled) | |
334 | return 0; | |
335 | ||
2f16f631 MCC |
336 | for (pos = 0; pos < len; pos++) |
337 | handle_event(input_dev, &evs[pos]); | |
338 | ||
ada39630 MCC |
339 | return rc; |
340 | } | |
341 | ||
20d5f116 MCC |
342 | static int ir_nec_register(struct input_dev *input_dev) |
343 | { | |
344 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); | |
345 | struct decoder_data *data; | |
346 | int rc; | |
347 | ||
348 | rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group); | |
349 | if (rc < 0) | |
350 | return rc; | |
351 | ||
352 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
353 | if (!data) { | |
354 | sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group); | |
355 | return -ENOMEM; | |
356 | } | |
357 | ||
358 | data->ir_dev = ir_dev; | |
359 | data->enabled = 1; | |
360 | ||
361 | spin_lock(&decoder_lock); | |
362 | list_add_tail(&data->list, &decoder_list); | |
363 | spin_unlock(&decoder_lock); | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | static int ir_nec_unregister(struct input_dev *input_dev) | |
369 | { | |
370 | struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); | |
371 | static struct decoder_data *data; | |
372 | ||
373 | data = get_decoder_data(ir_dev); | |
374 | if (!data) | |
375 | return 0; | |
376 | ||
377 | sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group); | |
378 | ||
379 | spin_lock(&decoder_lock); | |
380 | list_del(&data->list); | |
381 | spin_unlock(&decoder_lock); | |
382 | ||
383 | return 0; | |
384 | } | |
385 | ||
995187be | 386 | static struct ir_raw_handler nec_handler = { |
20d5f116 MCC |
387 | .decode = ir_nec_decode, |
388 | .raw_register = ir_nec_register, | |
389 | .raw_unregister = ir_nec_unregister, | |
995187be MCC |
390 | }; |
391 | ||
392 | static int __init ir_nec_decode_init(void) | |
393 | { | |
394 | ir_raw_handler_register(&nec_handler); | |
395 | ||
396 | printk(KERN_INFO "IR NEC protocol handler initialized\n"); | |
397 | return 0; | |
398 | } | |
399 | ||
400 | static void __exit ir_nec_decode_exit(void) | |
401 | { | |
402 | ir_raw_handler_unregister(&nec_handler); | |
403 | } | |
404 | ||
405 | module_init(ir_nec_decode_init); | |
406 | module_exit(ir_nec_decode_exit); | |
407 | ||
408 | MODULE_LICENSE("GPL"); | |
409 | MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); | |
410 | MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); | |
411 | MODULE_DESCRIPTION("NEC IR protocol decoder"); |