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 = from_timer(raw, t, mce_kbd.rx_timeout);
113 unsigned char maskcode;
114 unsigned long flags;
115 int i;
116
117 dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n");
118
119 spin_lock_irqsave(&raw->mce_kbd.keylock, flags);
120
121 if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) {
122 for (i = 0; i < 7; i++) {
123 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
124 input_report_key(raw->dev->input_dev, maskcode, 0);
125 }
126
127 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
128 input_report_key(raw->dev->input_dev, kbd_keycodes[i],
129 0);
130
131 input_sync(raw->dev->input_dev);
132 }
133 spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags);
134 }
135
mce_kbd_mode(struct mce_kbd_dec * data)136 static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
137 {
138 switch (data->header & MCIR2_MODE_MASK) {
139 case MCIR2_KEYBOARD_HEADER:
140 return MCIR2_MODE_KEYBOARD;
141 case MCIR2_MOUSE_HEADER:
142 return MCIR2_MODE_MOUSE;
143 default:
144 return MCIR2_MODE_UNKNOWN;
145 }
146 }
147
ir_mce_kbd_process_keyboard_data(struct rc_dev * dev,u32 scancode)148 static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode)
149 {
150 u8 keydata1 = (scancode >> 8) & 0xff;
151 u8 keydata2 = (scancode >> 16) & 0xff;
152 u8 shiftmask = scancode & 0xff;
153 unsigned char maskcode;
154 int i, keystate;
155
156 dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n",
157 keydata2, keydata1, shiftmask);
158
159 for (i = 0; i < 7; i++) {
160 maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
161 if (shiftmask & (1 << i))
162 keystate = 1;
163 else
164 keystate = 0;
165 input_report_key(dev->input_dev, maskcode, keystate);
166 }
167
168 if (keydata1)
169 input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1);
170 if (keydata2)
171 input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1);
172
173 if (!keydata1 && !keydata2) {
174 for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
175 input_report_key(dev->input_dev, kbd_keycodes[i], 0);
176 }
177 }
178
ir_mce_kbd_process_mouse_data(struct rc_dev * dev,u32 scancode)179 static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode)
180 {
181 /* raw mouse coordinates */
182 u8 xdata = (scancode >> 7) & 0x7f;
183 u8 ydata = (scancode >> 14) & 0x7f;
184 int x, y;
185 /* mouse buttons */
186 bool right = scancode & 0x40;
187 bool left = scancode & 0x20;
188
189 if (xdata & 0x40)
190 x = -((~xdata & 0x7f) + 1);
191 else
192 x = xdata;
193
194 if (ydata & 0x40)
195 y = -((~ydata & 0x7f) + 1);
196 else
197 y = ydata;
198
199 dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n",
200 x, y, left ? "L" : "", right ? "R" : "");
201
202 input_report_rel(dev->input_dev, REL_X, x);
203 input_report_rel(dev->input_dev, REL_Y, y);
204
205 input_report_key(dev->input_dev, BTN_LEFT, left);
206 input_report_key(dev->input_dev, BTN_RIGHT, right);
207 }
208
209 /**
210 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
211 * @dev: the struct rc_dev descriptor of the device
212 * @ev: the struct ir_raw_event descriptor of the pulse/space
213 *
214 * This function returns -EINVAL if the pulse violates the state machine
215 */
ir_mce_kbd_decode(struct rc_dev * dev,struct ir_raw_event ev)216 static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
217 {
218 struct mce_kbd_dec *data = &dev->raw->mce_kbd;
219 u32 scancode;
220 unsigned long delay;
221 struct lirc_scancode lsc = {};
222
223 if (!is_timing_event(ev)) {
224 if (ev.overflow)
225 data->state = STATE_INACTIVE;
226 return 0;
227 }
228
229 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
230 goto out;
231
232 again:
233 dev_dbg(&dev->dev, "started at state %i (%uus %s)\n",
234 data->state, ev.duration, TO_STR(ev.pulse));
235
236 if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
237 return 0;
238
239 switch (data->state) {
240
241 case STATE_INACTIVE:
242 if (!ev.pulse)
243 break;
244
245 /* Note: larger margin on first pulse since each MCIR2_UNIT
246 is quite short and some hardware takes some time to
247 adjust to the signal */
248 if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
249 break;
250
251 data->state = STATE_HEADER_BIT_START;
252 data->count = 0;
253 data->header = 0;
254 return 0;
255
256 case STATE_HEADER_BIT_START:
257 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
258 break;
259
260 data->header <<= 1;
261 if (ev.pulse)
262 data->header |= 1;
263 data->count++;
264 data->state = STATE_HEADER_BIT_END;
265 return 0;
266
267 case STATE_HEADER_BIT_END:
268 decrease_duration(&ev, MCIR2_BIT_END);
269
270 if (data->count != MCIR2_HEADER_NBITS) {
271 data->state = STATE_HEADER_BIT_START;
272 goto again;
273 }
274
275 switch (mce_kbd_mode(data)) {
276 case MCIR2_MODE_KEYBOARD:
277 data->wanted_bits = MCIR2_KEYBOARD_NBITS;
278 break;
279 case MCIR2_MODE_MOUSE:
280 data->wanted_bits = MCIR2_MOUSE_NBITS;
281 break;
282 default:
283 dev_dbg(&dev->dev, "not keyboard or mouse data\n");
284 goto out;
285 }
286
287 data->count = 0;
288 data->body = 0;
289 data->state = STATE_BODY_BIT_START;
290 goto again;
291
292 case STATE_BODY_BIT_START:
293 if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
294 break;
295
296 data->body <<= 1;
297 if (ev.pulse)
298 data->body |= 1;
299 data->count++;
300 data->state = STATE_BODY_BIT_END;
301 return 0;
302
303 case STATE_BODY_BIT_END:
304 if (data->count == data->wanted_bits)
305 data->state = STATE_FINISHED;
306 else
307 data->state = STATE_BODY_BIT_START;
308
309 decrease_duration(&ev, MCIR2_BIT_END);
310 goto again;
311
312 case STATE_FINISHED:
313 if (ev.pulse)
314 break;
315
316 switch (data->wanted_bits) {
317 case MCIR2_KEYBOARD_NBITS:
318 scancode = data->body & 0xffffff;
319 dev_dbg(&dev->dev, "keyboard data 0x%08x\n",
320 data->body);
321 spin_lock(&data->keylock);
322 if (scancode) {
323 delay = usecs_to_jiffies(dev->timeout) +
324 msecs_to_jiffies(100);
325 mod_timer(&data->rx_timeout, jiffies + delay);
326 } else {
327 del_timer(&data->rx_timeout);
328 }
329 /* Pass data to keyboard buffer parser */
330 ir_mce_kbd_process_keyboard_data(dev, scancode);
331 spin_unlock(&data->keylock);
332 lsc.rc_proto = RC_PROTO_MCIR2_KBD;
333 break;
334 case MCIR2_MOUSE_NBITS:
335 scancode = data->body & 0x1fffff;
336 dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode);
337 /* Pass data to mouse buffer parser */
338 ir_mce_kbd_process_mouse_data(dev, scancode);
339 lsc.rc_proto = RC_PROTO_MCIR2_MSE;
340 break;
341 default:
342 dev_dbg(&dev->dev, "not keyboard or mouse data\n");
343 goto out;
344 }
345
346 lsc.scancode = scancode;
347 lirc_scancode_event(dev, &lsc);
348 data->state = STATE_INACTIVE;
349 input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode);
350 input_sync(dev->input_dev);
351 return 0;
352 }
353
354 out:
355 dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n",
356 data->state, ev.duration, TO_STR(ev.pulse));
357 data->state = STATE_INACTIVE;
358 return -EINVAL;
359 }
360
ir_mce_kbd_register(struct rc_dev * dev)361 static int ir_mce_kbd_register(struct rc_dev *dev)
362 {
363 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
364
365 timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0);
366 spin_lock_init(&mce_kbd->keylock);
367
368 return 0;
369 }
370
ir_mce_kbd_unregister(struct rc_dev * dev)371 static int ir_mce_kbd_unregister(struct rc_dev *dev)
372 {
373 struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
374
375 del_timer_sync(&mce_kbd->rx_timeout);
376
377 return 0;
378 }
379
380 static const struct ir_raw_timings_manchester ir_mce_kbd_timings = {
381 .leader_pulse = MCIR2_PREFIX_PULSE,
382 .invert = 1,
383 .clock = MCIR2_UNIT,
384 .trailer_space = MCIR2_UNIT * 10,
385 };
386
387 /**
388 * ir_mce_kbd_encode() - Encode a scancode as a stream of raw events
389 *
390 * @protocol: protocol to encode
391 * @scancode: scancode to encode
392 * @events: array of raw ir events to write into
393 * @max: maximum size of @events
394 *
395 * Returns: The number of events written.
396 * -ENOBUFS if there isn't enough space in the array to fit the
397 * encoding. In this case all @max events will have been written.
398 */
ir_mce_kbd_encode(enum rc_proto protocol,u32 scancode,struct ir_raw_event * events,unsigned int max)399 static int ir_mce_kbd_encode(enum rc_proto protocol, u32 scancode,
400 struct ir_raw_event *events, unsigned int max)
401 {
402 struct ir_raw_event *e = events;
403 int len, ret;
404 u64 raw;
405
406 if (protocol == RC_PROTO_MCIR2_KBD) {
407 raw = scancode |
408 ((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS);
409 len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS;
410 } else {
411 raw = scancode |
412 ((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS);
413 len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS;
414 }
415
416 ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw);
417 if (ret < 0)
418 return ret;
419
420 return e - events;
421 }
422
423 static struct ir_raw_handler mce_kbd_handler = {
424 .protocols = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE,
425 .decode = ir_mce_kbd_decode,
426 .encode = ir_mce_kbd_encode,
427 .raw_register = ir_mce_kbd_register,
428 .raw_unregister = ir_mce_kbd_unregister,
429 .carrier = 36000,
430 .min_timeout = MCIR2_MAX_LEN + MCIR2_UNIT / 2,
431 };
432
ir_mce_kbd_decode_init(void)433 static int __init ir_mce_kbd_decode_init(void)
434 {
435 ir_raw_handler_register(&mce_kbd_handler);
436
437 printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
438 return 0;
439 }
440
ir_mce_kbd_decode_exit(void)441 static void __exit ir_mce_kbd_decode_exit(void)
442 {
443 ir_raw_handler_unregister(&mce_kbd_handler);
444 }
445
446 module_init(ir_mce_kbd_decode_init);
447 module_exit(ir_mce_kbd_decode_exit);
448
449 MODULE_LICENSE("GPL");
450 MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
451 MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");
452