ir-mce_kbd-decoder.c 13 KB

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