1/* ir-mce_kbd-decoder.c - A decoder for the RC6-ish keyboard/mouse IR protocol
2 * used by the Microsoft Remote Keyboard for Windows Media Center Edition,
3 * referred to by Microsoft's Windows Media Center remote specification docs
4 * as "an internal protocol called MCIR-2".
5 *
6 * Copyright (C) 2011 by Jarod Wilson <jarod@redhat.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17#include <linux/module.h>
18
19#include "rc-core-priv.h"
20
21/*
22 * This decoder currently supports:
23 * - MCIR-2 29-bit IR signals used for mouse movement and buttons
24 * - MCIR-2 32-bit IR signals used for standard keyboard keys
25 *
26 * The media keys on the keyboard send RC-6 signals that are inditinguishable
27 * from the keys of the same name on the stock MCE remote, and will be handled
28 * by the standard RC-6 decoder, and be made available to the system via the
29 * input device for the remote, rather than the keyboard/mouse one.
30 */
31
32#define MCIR2_UNIT		333333	/* ns */
33#define MCIR2_HEADER_NBITS	5
34#define MCIR2_MOUSE_NBITS	29
35#define MCIR2_KEYBOARD_NBITS	32
36#define MCIR2_PREFIX_PULSE	(8 * MCIR2_UNIT)
37#define MCIR2_PREFIX_SPACE	(1 * MCIR2_UNIT)
38#define MCIR2_MAX_LEN		(3 * MCIR2_UNIT)
39#define MCIR2_BIT_START		(1 * MCIR2_UNIT)
40#define MCIR2_BIT_END		(1 * MCIR2_UNIT)
41#define MCIR2_BIT_0		(1 * MCIR2_UNIT)
42#define MCIR2_BIT_SET		(2 * MCIR2_UNIT)
43#define MCIR2_MODE_MASK		0xf	/* for the header bits */
44#define MCIR2_KEYBOARD_HEADER	0x4
45#define MCIR2_MOUSE_HEADER	0x1
46#define MCIR2_MASK_KEYS_START	0xe0
47
48enum mce_kbd_mode {
49	MCIR2_MODE_KEYBOARD,
50	MCIR2_MODE_MOUSE,
51	MCIR2_MODE_UNKNOWN,
52};
53
54enum mce_kbd_state {
55	STATE_INACTIVE,
56	STATE_HEADER_BIT_START,
57	STATE_HEADER_BIT_END,
58	STATE_BODY_BIT_START,
59	STATE_BODY_BIT_END,
60	STATE_FINISHED,
61};
62
63static unsigned char kbd_keycodes[256] = {
64	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_A,
65	KEY_B,		KEY_C,		KEY_D,		KEY_E,		KEY_F,
66	KEY_G,		KEY_H,		KEY_I,		KEY_J,		KEY_K,
67	KEY_L,		KEY_M,		KEY_N,		KEY_O,		KEY_P,
68	KEY_Q,		KEY_R,		KEY_S,		KEY_T,		KEY_U,
69	KEY_V,		KEY_W,		KEY_X,		KEY_Y,		KEY_Z,
70	KEY_1,		KEY_2,		KEY_3,		KEY_4,		KEY_5,
71	KEY_6,		KEY_7,		KEY_8,		KEY_9,		KEY_0,
72	KEY_ENTER,	KEY_ESC,	KEY_BACKSPACE,	KEY_TAB,	KEY_SPACE,
73	KEY_MINUS,	KEY_EQUAL,	KEY_LEFTBRACE,	KEY_RIGHTBRACE,	KEY_BACKSLASH,
74	KEY_RESERVED,	KEY_SEMICOLON,	KEY_APOSTROPHE,	KEY_GRAVE,	KEY_COMMA,
75	KEY_DOT,	KEY_SLASH,	KEY_CAPSLOCK,	KEY_F1,		KEY_F2,
76	KEY_F3,		KEY_F4,		KEY_F5,		KEY_F6,		KEY_F7,
77	KEY_F8,		KEY_F9,		KEY_F10,	KEY_F11,	KEY_F12,
78	KEY_SYSRQ,	KEY_SCROLLLOCK,	KEY_PAUSE,	KEY_INSERT,	KEY_HOME,
79	KEY_PAGEUP,	KEY_DELETE,	KEY_END,	KEY_PAGEDOWN,	KEY_RIGHT,
80	KEY_LEFT,	KEY_DOWN,	KEY_UP,		KEY_NUMLOCK,	KEY_KPSLASH,
81	KEY_KPASTERISK,	KEY_KPMINUS,	KEY_KPPLUS,	KEY_KPENTER,	KEY_KP1,
82	KEY_KP2,	KEY_KP3,	KEY_KP4,	KEY_KP5,	KEY_KP6,
83	KEY_KP7,	KEY_KP8,	KEY_KP9,	KEY_KP0,	KEY_KPDOT,
84	KEY_102ND,	KEY_COMPOSE,	KEY_POWER,	KEY_KPEQUAL,	KEY_F13,
85	KEY_F14,	KEY_F15,	KEY_F16,	KEY_F17,	KEY_F18,
86	KEY_F19,	KEY_F20,	KEY_F21,	KEY_F22,	KEY_F23,
87	KEY_F24,	KEY_OPEN,	KEY_HELP,	KEY_PROPS,	KEY_FRONT,
88	KEY_STOP,	KEY_AGAIN,	KEY_UNDO,	KEY_CUT,	KEY_COPY,
89	KEY_PASTE,	KEY_FIND,	KEY_MUTE,	KEY_VOLUMEUP,	KEY_VOLUMEDOWN,
90	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_KPCOMMA,	KEY_RESERVED,
91	KEY_RO,		KEY_KATAKANAHIRAGANA, KEY_YEN,	KEY_HENKAN,	KEY_MUHENKAN,
92	KEY_KPJPCOMMA,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_HANGUEL,
93	KEY_HANJA,	KEY_KATAKANA,	KEY_HIRAGANA,	KEY_ZENKAKUHANKAKU, 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_RESERVED,
101	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
102	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
103	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
104	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
105	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
106	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
107	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
108	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,	KEY_LEFTCTRL,
109	KEY_LEFTSHIFT,	KEY_LEFTALT,	KEY_LEFTMETA,	KEY_RIGHTCTRL,	KEY_RIGHTSHIFT,
110	KEY_RIGHTALT,	KEY_RIGHTMETA,	KEY_PLAYPAUSE,	KEY_STOPCD,	KEY_PREVIOUSSONG,
111	KEY_NEXTSONG,	KEY_EJECTCD,	KEY_VOLUMEUP,	KEY_VOLUMEDOWN,	KEY_MUTE,
112	KEY_WWW,	KEY_BACK,	KEY_FORWARD,	KEY_STOP,	KEY_FIND,
113	KEY_SCROLLUP,	KEY_SCROLLDOWN,	KEY_EDIT,	KEY_SLEEP,	KEY_COFFEE,
114	KEY_REFRESH,	KEY_CALC,	KEY_RESERVED,	KEY_RESERVED,	KEY_RESERVED,
115	KEY_RESERVED
116};
117
118static void mce_kbd_rx_timeout(unsigned long data)
119{
120	struct mce_kbd_dec *mce_kbd = (struct mce_kbd_dec *)data;
121	int i;
122	unsigned char maskcode;
123
124	IR_dprintk(2, "timer callback clearing all keys\n");
125
126	for (i = 0; i < 7; i++) {
127		maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
128		input_report_key(mce_kbd->idev, maskcode, 0);
129	}
130
131	for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
132		input_report_key(mce_kbd->idev, kbd_keycodes[i], 0);
133}
134
135static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
136{
137	switch (data->header & MCIR2_MODE_MASK) {
138	case MCIR2_KEYBOARD_HEADER:
139		return MCIR2_MODE_KEYBOARD;
140	case MCIR2_MOUSE_HEADER:
141		return MCIR2_MODE_MOUSE;
142	default:
143		return MCIR2_MODE_UNKNOWN;
144	}
145}
146
147static void ir_mce_kbd_process_keyboard_data(struct input_dev *idev,
148					     u32 scancode)
149{
150	u8 keydata   = (scancode >> 8) & 0xff;
151	u8 shiftmask = scancode & 0xff;
152	unsigned char keycode, maskcode;
153	int i, keystate;
154
155	IR_dprintk(1, "keyboard: keydata = 0x%02x, shiftmask = 0x%02x\n",
156		   keydata, shiftmask);
157
158	for (i = 0; i < 7; i++) {
159		maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
160		if (shiftmask & (1 << i))
161			keystate = 1;
162		else
163			keystate = 0;
164		input_report_key(idev, maskcode, keystate);
165	}
166
167	if (keydata) {
168		keycode = kbd_keycodes[keydata];
169		input_report_key(idev, keycode, 1);
170	} else {
171		for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
172			input_report_key(idev, kbd_keycodes[i], 0);
173	}
174}
175
176static void ir_mce_kbd_process_mouse_data(struct input_dev *idev, u32 scancode)
177{
178	/* raw mouse coordinates */
179	u8 xdata = (scancode >> 7) & 0x7f;
180	u8 ydata = (scancode >> 14) & 0x7f;
181	int x, y;
182	/* mouse buttons */
183	bool right = scancode & 0x40;
184	bool left  = scancode & 0x20;
185
186	if (xdata & 0x40)
187		x = -((~xdata & 0x7f) + 1);
188	else
189		x = xdata;
190
191	if (ydata & 0x40)
192		y = -((~ydata & 0x7f) + 1);
193	else
194		y = ydata;
195
196	IR_dprintk(1, "mouse: x = %d, y = %d, btns = %s%s\n",
197		   x, y, left ? "L" : "", right ? "R" : "");
198
199	input_report_rel(idev, REL_X, x);
200	input_report_rel(idev, REL_Y, y);
201
202	input_report_key(idev, BTN_LEFT, left);
203	input_report_key(idev, BTN_RIGHT, right);
204}
205
206/**
207 * ir_mce_kbd_decode() - Decode one mce_kbd pulse or space
208 * @dev:	the struct rc_dev descriptor of the device
209 * @ev:		the struct ir_raw_event descriptor of the pulse/space
210 *
211 * This function returns -EINVAL if the pulse violates the state machine
212 */
213static int ir_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
214{
215	struct mce_kbd_dec *data = &dev->raw->mce_kbd;
216	u32 scancode;
217	unsigned long delay;
218
219	if (!(dev->raw->enabled_protocols & RC_TYPE_MCE_KBD))
220		return 0;
221
222	if (!is_timing_event(ev)) {
223		if (ev.reset)
224			data->state = STATE_INACTIVE;
225		return 0;
226	}
227
228	if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
229		goto out;
230
231again:
232	IR_dprintk(2, "started at state %i (%uus %s)\n",
233		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
234
235	if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
236		return 0;
237
238	switch (data->state) {
239
240	case STATE_INACTIVE:
241		if (!ev.pulse)
242			break;
243
244		/* Note: larger margin on first pulse since each MCIR2_UNIT
245		   is quite short and some hardware takes some time to
246		   adjust to the signal */
247		if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
248			break;
249
250		data->state = STATE_HEADER_BIT_START;
251		data->count = 0;
252		data->header = 0;
253		return 0;
254
255	case STATE_HEADER_BIT_START:
256		if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
257			break;
258
259		data->header <<= 1;
260		if (ev.pulse)
261			data->header |= 1;
262		data->count++;
263		data->state = STATE_HEADER_BIT_END;
264		return 0;
265
266	case STATE_HEADER_BIT_END:
267		if (!is_transition(&ev, &dev->raw->prev_ev))
268			break;
269
270		decrease_duration(&ev, MCIR2_BIT_END);
271
272		if (data->count != MCIR2_HEADER_NBITS) {
273			data->state = STATE_HEADER_BIT_START;
274			goto again;
275		}
276
277		switch (mce_kbd_mode(data)) {
278		case MCIR2_MODE_KEYBOARD:
279			data->wanted_bits = MCIR2_KEYBOARD_NBITS;
280			break;
281		case MCIR2_MODE_MOUSE:
282			data->wanted_bits = MCIR2_MOUSE_NBITS;
283			break;
284		default:
285			IR_dprintk(1, "not keyboard or mouse data\n");
286			goto out;
287		}
288
289		data->count = 0;
290		data->body = 0;
291		data->state = STATE_BODY_BIT_START;
292		goto again;
293
294	case STATE_BODY_BIT_START:
295		if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
296			break;
297
298		data->body <<= 1;
299		if (ev.pulse)
300			data->body |= 1;
301		data->count++;
302		data->state = STATE_BODY_BIT_END;
303		return 0;
304
305	case STATE_BODY_BIT_END:
306		if (!is_transition(&ev, &dev->raw->prev_ev))
307			break;
308
309		if (data->count == data->wanted_bits)
310			data->state = STATE_FINISHED;
311		else
312			data->state = STATE_BODY_BIT_START;
313
314		decrease_duration(&ev, MCIR2_BIT_END);
315		goto again;
316
317	case STATE_FINISHED:
318		if (ev.pulse)
319			break;
320
321		switch (data->wanted_bits) {
322		case MCIR2_KEYBOARD_NBITS:
323			scancode = data->body & 0xffff;
324			IR_dprintk(1, "keyboard data 0x%08x\n", data->body);
325			if (dev->timeout)
326				delay = usecs_to_jiffies(dev->timeout / 1000);
327			else
328				delay = msecs_to_jiffies(100);
329			mod_timer(&data->rx_timeout, jiffies + delay);
330			/* Pass data to keyboard buffer parser */
331			ir_mce_kbd_process_keyboard_data(data->idev, scancode);
332			break;
333		case MCIR2_MOUSE_NBITS:
334			scancode = data->body & 0x1fffff;
335			IR_dprintk(1, "mouse data 0x%06x\n", scancode);
336			/* Pass data to mouse buffer parser */
337			ir_mce_kbd_process_mouse_data(data->idev, scancode);
338			break;
339		default:
340			IR_dprintk(1, "not keyboard or mouse data\n");
341			goto out;
342		}
343
344		data->state = STATE_INACTIVE;
345		input_sync(data->idev);
346		return 0;
347	}
348
349out:
350	IR_dprintk(1, "failed at state %i (%uus %s)\n",
351		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
352	data->state = STATE_INACTIVE;
353	input_sync(data->idev);
354	return -EINVAL;
355}
356
357static int ir_mce_kbd_register(struct rc_dev *dev)
358{
359	struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
360	struct input_dev *idev;
361	int i, ret;
362
363	idev = input_allocate_device();
364	if (!idev)
365		return -ENOMEM;
366
367	snprintf(mce_kbd->name, sizeof(mce_kbd->name),
368		 "MCE IR Keyboard/Mouse (%s)", dev->driver_name);
369	strlcat(mce_kbd->phys, "/input0", sizeof(mce_kbd->phys));
370
371	idev->name = mce_kbd->name;
372	idev->phys = mce_kbd->phys;
373
374	/* Keyboard bits */
375	set_bit(EV_KEY, idev->evbit);
376	set_bit(EV_REP, idev->evbit);
377	for (i = 0; i < sizeof(kbd_keycodes); i++)
378		set_bit(kbd_keycodes[i], idev->keybit);
379
380	/* Mouse bits */
381	set_bit(EV_REL, idev->evbit);
382	set_bit(REL_X, idev->relbit);
383	set_bit(REL_Y, idev->relbit);
384	set_bit(BTN_LEFT, idev->keybit);
385	set_bit(BTN_RIGHT, idev->keybit);
386
387	/* Report scancodes too */
388	set_bit(EV_MSC, idev->evbit);
389	set_bit(MSC_SCAN, idev->mscbit);
390
391	setup_timer(&mce_kbd->rx_timeout, mce_kbd_rx_timeout,
392		    (unsigned long)mce_kbd);
393
394	input_set_drvdata(idev, mce_kbd);
395
396#if 0
397	/* Adding this reference means two input devices are associated with
398	 * this rc-core device, which ir-keytable doesn't cope with yet */
399	idev->dev.parent = &dev->dev;
400#endif
401
402	ret = input_register_device(idev);
403	if (ret < 0) {
404		input_free_device(idev);
405		return -EIO;
406	}
407
408	mce_kbd->idev = idev;
409
410	return 0;
411}
412
413static int ir_mce_kbd_unregister(struct rc_dev *dev)
414{
415	struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
416	struct input_dev *idev = mce_kbd->idev;
417
418	del_timer_sync(&mce_kbd->rx_timeout);
419	input_unregister_device(idev);
420
421	return 0;
422}
423
424static struct ir_raw_handler mce_kbd_handler = {
425	.protocols	= RC_TYPE_MCE_KBD,
426	.decode		= ir_mce_kbd_decode,
427	.raw_register	= ir_mce_kbd_register,
428	.raw_unregister	= ir_mce_kbd_unregister,
429};
430
431static int __init ir_mce_kbd_decode_init(void)
432{
433	ir_raw_handler_register(&mce_kbd_handler);
434
435	printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
436	return 0;
437}
438
439static void __exit ir_mce_kbd_decode_exit(void)
440{
441	ir_raw_handler_unregister(&mce_kbd_handler);
442}
443
444module_init(ir_mce_kbd_decode_init);
445module_exit(ir_mce_kbd_decode_exit);
446
447MODULE_LICENSE("GPL");
448MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
449MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");
450