1 // SPDX-License-Identifier: GPL-2.0-only
2 /* ir-mce_kbd-decoder.c - A decoder for the RC6-ish keyboard/mouse IR protocol
3 * used by the Microsoft Remote Keyboard for Windows Media Center Edition,
4 * referred to by Microsoft's Windows Media Center remote specification docs
5 * as "an internal protocol called MCIR-2".
6 *
7 * Copyright (C) 2011 by Jarod Wilson <jarod@redhat.com>
8 */
9 #include <linux/module.h>
10
11 #include "rc-core-priv.h"
12
13 /*
14 * This decoder currently supports:
15 * - MCIR-2 29-bit IR signals used for mouse movement and buttons
16 * - MCIR-2 32-bit IR signals used for standard keyboard keys
17 *
18 * The media keys on the keyboard send RC-6 signals that are indistinguishable
19 * from the keys of the same name on the stock MCE remote, and will be handled
20 * by the standard RC-6 decoder, and be made available to the system via the
21 * input device for the remote, rather than the keyboard/mouse one.
22 */
23
24 #define MCIR2_UNIT 333 /* us */
25 #define MCIR2_HEADER_NBITS 5
26 #define MCIR2_MOUSE_NBITS 29
27 #define MCIR2_KEYBOARD_NBITS 32
28 #define MCIR2_PREFIX_PULSE (8 * MCIR2_UNIT)
29 #define MCIR2_PREFIX_SPACE (1 * MCIR2_UNIT)
30 #define MCIR2_MAX_LEN (3 * MCIR2_UNIT)
31 #define MCIR2_BIT_START (1 * MCIR2_UNIT)
32 #define MCIR2_BIT_END (1 * MCIR2_UNIT)
33 #define MCIR2_BIT_0 (1 * MCIR2_UNIT)
34 #define MCIR2_BIT_SET (2 * MCIR2_UNIT)
35 #define MCIR2_MODE_MASK 0xf /* for the header bits */
36 #define MCIR2_KEYBOARD_HEADER 0x4
37 #define MCIR2_MOUSE_HEADER 0x1
38 #define MCIR2_MASK_KEYS_START 0xe0
39
40 enum mce_kbd_mode {
41 MCIR2_MODE_KEYBOARD,
42 MCIR2_MODE_MOUSE,
43 MCIR2_MODE_UNKNOWN,
44 };
45
46 enum mce_kbd_state {
47 STATE_INACTIVE,
48 STATE_HEADER_BIT_START,
49 STATE_HEADER_BIT_END,
50 STATE_BODY_BIT_START,
51 STATE_BODY_BIT_END,
52 STATE_FINISHED,
53 };
54
55 static unsigned char kbd_keycodes[256] = {
56 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_A,
57 KEY_B, KEY_C, KEY_D, KEY_E, KEY_F,
58 KEY_G, KEY_H, KEY_I, KEY_J, KEY_K,
59 KEY_L, KEY_M, KEY_N, KEY_O, KEY_P,
60 KEY_Q, KEY_R, KEY_S, KEY_T, KEY_U,
61 KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z,
62 KEY_1, KEY_2, KEY_3, KEY_4, KEY_5,
63 KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
64 KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB, KEY_SPACE,
65 KEY_MINUS, KEY_EQUAL, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH,
66 KEY_BACKSLASH, KEY_SEMICOLON, KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA,
67 KEY_DOT, KEY_SLASH, KEY_CAPSLOCK, KEY_F1, KEY_F2,
68 KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7,
69 KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12,
70 KEY_SYSRQ, KEY_SCROLLLOCK, KEY_PAUSE, KEY_INSERT, KEY_HOME,
71 KEY_PAGEUP, KEY_DELETE, KEY_END, KEY_PAGEDOWN, KEY_RIGHT,
72 KEY_LEFT, KEY_DOWN, KEY_UP, KEY_NUMLOCK, KEY_KPSLASH,
73 KEY_KPASTERISK, KEY_KPMINUS, KEY_KPPLUS, KEY_KPENTER, KEY_KP1,
74 KEY_KP2, KEY_KP3, KEY_KP4, KEY_KP5, KEY_KP6,
75 KEY_KP7, KEY_KP8, KEY_KP9, KEY_KP0, KEY_KPDOT,
76 KEY_102ND, KEY_COMPOSE, KEY_POWER, KEY_KPEQUAL, KEY_F13,
77 KEY_F14, KEY_F15, KEY_F16, KEY_F17, KEY_F18,
78 KEY_F19, KEY_F20, KEY_F21, KEY_F22, KEY_F23,
79 KEY_F24, KEY_OPEN, KEY_HELP, KEY_PROPS, KEY_FRONT,
80 KEY_STOP, KEY_AGAIN, KEY_UNDO, KEY_CUT, KEY_COPY,
81 KEY_PASTE, KEY_FIND, KEY_MUTE, KEY_VOLUMEUP, KEY_VOLUMEDOWN,
82 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_KPCOMMA, KEY_RESERVED,
83 KEY_RO, KEY_KATAKANAHIRAGANA, KEY_YEN, KEY_HENKAN, KEY_MUHENKAN,
84 KEY_KPJPCOMMA, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_HANGUEL,
85 KEY_HANJA, KEY_KATAKANA, KEY_HIRAGANA, KEY_ZENKAKUHANKAKU, KEY_RESERVED,
86 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
87 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
88 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
89 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
90 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
91 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
92 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
93 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
94 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
95 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
96 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
97 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
98 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
99 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
100 KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_LEFTCTRL,
101 KEY_LEFTSHIFT, KEY_LEFTALT, KEY_LEFTMETA, KEY_RIGHTCTRL, KEY_RIGHTSHIFT,
102 KEY_RIGHTALT, KEY_RIGHTMETA, KEY_PLAYPAUSE, KEY_STOPCD, KEY_PREVIOUSSONG,
103 KEY_NEXTSONG, KEY_EJECTCD, KEY_VOLUMEUP, KEY_VOLUMEDOWN, KEY_MUTE,
104 KEY_WWW, KEY_BACK, KEY_FORWARD, KEY_STOP, KEY_FIND,
105 KEY_SCROLLUP, KEY_SCROLLDOWN, KEY_EDIT, KEY_SLEEP, KEY_COFFEE,
106 KEY_REFRESH, KEY_CALC, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
107 KEY_RESERVED
108 };
109
mce_kbd_rx_timeout(struct timer_list * t)110 static void mce_kbd_rx_timeout(struct timer_list *t)
111 {
112 struct ir_raw_event_ctrl *raw = timer_container_of(raw, t,
113 mce_kbd.rx_timeout);
114 unsigned char maskcode;
115 unsigned long flags;
116 int i;
117
118 dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n");
119
120 spin_lock_irqsave(&raw->mce_kbd.keylock, flags);
121
122 if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) {
123 for (i = 0; i < 7; i++) {
124 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
125 input_report_key(raw->dev->input_dev, maskcode, 0);
126 }
127
128 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
129 input_report_key(raw->dev->input_dev, kbd_keycodes[i],
130 0);
131
132 input_sync(raw->dev->input_dev);
133 }
134 spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags);
135 }
136
mce_kbd_mode(struct mce_kbd_dec * data)137 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
138 {
139 switch (data->header & MCIR2_MODE_MASK) {
140 case MCIR2_KEYBOARD_HEADER:
141 return MCIR2_MODE_KEYBOARD;
142 case MCIR2_MOUSE_HEADER:
143 return MCIR2_MODE_MOUSE;
144 default:
145 return MCIR2_MODE_UNKNOWN;
146 }
147 }
148
ir_mce_kbd_process_keyboard_data(struct rc_dev * dev,u32 scancode)149 static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode)
150 {
151 u8 keydata1 = (scancode >> 8) & 0xff;
152 u8 keydata2 = (scancode >> 16) & 0xff;
153 u8 shiftmask = scancode & 0xff;
154 unsigned char maskcode;
155 int i, keystate;
156
157 dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n",
158 keydata2, keydata1, shiftmask);
159
160 for (i = 0; i < 7; i++) {
161 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
162 if (shiftmask & (1 << i))
163 keystate = 1;
164 else
165 keystate = 0;
166 input_report_key(dev->input_dev, maskcode, keystate);
167 }
168
169 if (keydata1)
170 input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1);
171 if (keydata2)
172 input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1);
173
174 if (!keydata1 && !keydata2) {
175 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
176 input_report_key(dev->input_dev, kbd_keycodes[i], 0);
177 }
178 }
179
ir_mce_kbd_process_mouse_data(struct rc_dev * dev,u32 scancode)180 static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode)
181 {
182 /* raw mouse coordinates */
183 u8 xdata = (scancode >> 7) & 0x7f;
184 u8 ydata = (scancode >> 14) & 0x7f;
185 int x, y;
186 /* mouse buttons */
187 bool right = scancode & 0x40;
188 bool left = scancode & 0x20;
189
190 if (xdata & 0x40)
191 x = -((~xdata & 0x7f) + 1);
192 else
193 x = xdata;
194
195 if (ydata & 0x40)
196 y = -((~ydata & 0x7f) + 1);
197 else
198 y = ydata;
199
200 dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n",
201 x, y, left ? "L" : "", right ? "R" : "");
202
203 input_report_rel(dev->input_dev, REL_X, x);
204 input_report_rel(dev->input_dev, REL_Y, y);
205
206 input_report_key(dev->input_dev, BTN_LEFT, left);
207 input_report_key(dev->input_dev, BTN_RIGHT, right);
208 }
209
210 /**
211 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
212 * @dev: the struct rc_dev descriptor of the device
213 * @ev: the struct ir_raw_event descriptor of the pulse/space
214 *
215 * This function returns -EINVAL if the pulse violates the state machine
216 */
ir_mce_kbd_decode(struct rc_dev * dev,struct ir_raw_event ev)217 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
218 {
219 struct mce_kbd_dec *data = &dev->raw->mce_kbd;
220 u32 scancode;
221 unsigned long delay;
222 struct lirc_scancode lsc = {};
223
224 if (!is_timing_event(ev)) {
225 if (ev.overflow)
226 data->state = STATE_INACTIVE;
227 return 0;
228 }
229
230 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
231 goto out;
232
233 again:
234 dev_dbg(&dev->dev, "started at state %i (%uus %s)\n",
235 data->state, ev.duration, TO_STR(ev.pulse));
236
237 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
238 return 0;
239
240 switch (data->state) {
241
242 case STATE_INACTIVE:
243 if (!ev.pulse)
244 break;
245
246 /* Note: larger margin on first pulse since each MCIR2_UNIT
247 is quite short and some hardware takes some time to
248 adjust to the signal */
249 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
250 break;
251
252 data->state = STATE_HEADER_BIT_START;
253 data->count = 0;
254 data->header = 0;
255 return 0;
256
257 case STATE_HEADER_BIT_START:
258 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
259 break;
260
261 data->header <<= 1;
262 if (ev.pulse)
263 data->header |= 1;
264 data->count++;
265 data->state = STATE_HEADER_BIT_END;
266 return 0;
267
268 case STATE_HEADER_BIT_END:
269 decrease_duration(&ev, MCIR2_BIT_END);
270
271 if (data->count != MCIR2_HEADER_NBITS) {
272 data->state = STATE_HEADER_BIT_START;
273 goto again;
274 }
275
276 switch (mce_kbd_mode(data)) {
277 case MCIR2_MODE_KEYBOARD:
278 data->wanted_bits = MCIR2_KEYBOARD_NBITS;
279 break;
280 case MCIR2_MODE_MOUSE:
281 data->wanted_bits = MCIR2_MOUSE_NBITS;
282 break;
283 default:
284 dev_dbg(&dev->dev, "not keyboard or mouse data\n");
285 goto out;
286 }
287
288 data->count = 0;
289 data->body = 0;
290 data->state = STATE_BODY_BIT_START;
291 goto again;
292
293 case STATE_BODY_BIT_START:
294 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
295 break;
296
297 data->body <<= 1;
298 if (ev.pulse)
299 data->body |= 1;
300 data->count++;
301 data->state = STATE_BODY_BIT_END;
302 return 0;
303
304 case STATE_BODY_BIT_END:
305 if (data->count == data->wanted_bits)
306 data->state = STATE_FINISHED;
307 else
308 data->state = STATE_BODY_BIT_START;
309
310 decrease_duration(&ev, MCIR2_BIT_END);
311 goto again;
312
313 case STATE_FINISHED:
314 if (ev.pulse)
315 break;
316
317 switch (data->wanted_bits) {
318 case MCIR2_KEYBOARD_NBITS:
319 scancode = data->body & 0xffffff;
320 dev_dbg(&dev->dev, "keyboard data 0x%08x\n",
321 data->body);
322 spin_lock(&data->keylock);
323 if (scancode) {
324 delay = usecs_to_jiffies(dev->timeout) +
325 msecs_to_jiffies(100);
326 mod_timer(&data->rx_timeout, jiffies + delay);
327 } else {
328 timer_delete(&data->rx_timeout);
329 }
330 /* Pass data to keyboard buffer parser */
331 ir_mce_kbd_process_keyboard_data(dev, scancode);
332 spin_unlock(&data->keylock);
333 lsc.rc_proto = RC_PROTO_MCIR2_KBD;
334 break;
335 case MCIR2_MOUSE_NBITS:
336 scancode = data->body & 0x1fffff;
337 dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode);
338 /* Pass data to mouse buffer parser */
339 ir_mce_kbd_process_mouse_data(dev, scancode);
340 lsc.rc_proto = RC_PROTO_MCIR2_MSE;
341 break;
342 default:
343 dev_dbg(&dev->dev, "not keyboard or mouse data\n");
344 goto out;
345 }
346
347 lsc.scancode = scancode;
348 lirc_scancode_event(dev, &lsc);
349 data->state = STATE_INACTIVE;
350 input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode);
351 input_sync(dev->input_dev);
352 return 0;
353 }
354
355 out:
356 dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n",
357 data->state, ev.duration, TO_STR(ev.pulse));
358 data->state = STATE_INACTIVE;
359 return -EINVAL;
360 }
361
ir_mce_kbd_register(struct rc_dev * dev)362 static int ir_mce_kbd_register(struct rc_dev *dev)
363 {
364 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
365
366 timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0);
367 spin_lock_init(&mce_kbd->keylock);
368
369 return 0;
370 }
371
ir_mce_kbd_unregister(struct rc_dev * dev)372 static int ir_mce_kbd_unregister(struct rc_dev *dev)
373 {
374 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
375
376 timer_delete_sync(&mce_kbd->rx_timeout);
377
378 return 0;
379 }
380
381 static const struct ir_raw_timings_manchester ir_mce_kbd_timings = {
382 .leader_pulse = MCIR2_PREFIX_PULSE,
383 .invert = 1,
384 .clock = MCIR2_UNIT,
385 .trailer_space = MCIR2_UNIT * 10,
386 };
387
388 /**
389 * ir_mce_kbd_encode() - Encode a scancode as a stream of raw events
390 *
391 * @protocol: protocol to encode
392 * @scancode: scancode to encode
393 * @events: array of raw ir events to write into
394 * @max: maximum size of @events
395 *
396 * Returns: The number of events written.
397 * -ENOBUFS if there isn't enough space in the array to fit the
398 * encoding. In this case all @max events will have been written.
399 */
ir_mce_kbd_encode(enum rc_proto protocol,u32 scancode,struct ir_raw_event * events,unsigned int max)400 static int ir_mce_kbd_encode(enum rc_proto protocol, u32 scancode,
401 struct ir_raw_event *events, unsigned int max)
402 {
403 struct ir_raw_event *e = events;
404 int len, ret;
405 u64 raw;
406
407 if (protocol == RC_PROTO_MCIR2_KBD) {
408 raw = scancode |
409 ((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS);
410 len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS;
411 } else {
412 raw = scancode |
413 ((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS);
414 len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS;
415 }
416
417 ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw);
418 if (ret < 0)
419 return ret;
420
421 return e - events;
422 }
423
424 static struct ir_raw_handler mce_kbd_handler = {
425 .protocols = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE,
426 .decode = ir_mce_kbd_decode,
427 .encode = ir_mce_kbd_encode,
428 .raw_register = ir_mce_kbd_register,
429 .raw_unregister = ir_mce_kbd_unregister,
430 .carrier = 36000,
431 .min_timeout = MCIR2_MAX_LEN + MCIR2_UNIT / 2,
432 };
433
ir_mce_kbd_decode_init(void)434 static int __init ir_mce_kbd_decode_init(void)
435 {
436 ir_raw_handler_register(&mce_kbd_handler);
437
438 printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
439 return 0;
440 }
441
ir_mce_kbd_decode_exit(void)442 static void __exit ir_mce_kbd_decode_exit(void)
443 {
444 ir_raw_handler_unregister(&mce_kbd_handler);
445 }
446
447 module_init(ir_mce_kbd_decode_init);
448 module_exit(ir_mce_kbd_decode_exit);
449
450 MODULE_LICENSE("GPL");
451 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
452 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");
453