xref: /openbmc/u-boot/drivers/input/input.c (revision 72573543)
1 /*
2  * Translate key codes into ASCII
3  *
4  * Copyright (c) 2011 The Chromium OS Authors.
5  * (C) Copyright 2004 DENX Software Engineering, Wolfgang Denk, wd@denx.de
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  */
25 
26 #include <common.h>
27 #include <stdio_dev.h>
28 #include <input.h>
29 #include <linux/input.h>
30 
31 enum {
32 	/* These correspond to the lights on the keyboard */
33 	FLAG_NUM_LOCK		= 1 << 0,
34 	FLAG_CAPS_LOCK		= 1 << 1,
35 	FLAG_SCROLL_LOCK	= 1 << 2,
36 
37 	/* Special flag ORed with key code to indicate release */
38 	KEY_RELEASE		= 1 << 15,
39 	KEY_MASK		= 0xfff,
40 };
41 
42 /*
43  * These takes map key codes to ASCII. 0xff means no key, or special key.
44  * Three tables are provided - one for plain keys, one for when the shift
45  * 'modifier' key is pressed and one for when the ctrl modifier key is
46  * pressed.
47  */
48 static const uchar kbd_plain_xlate[] = {
49 	0xff, 0x1b, '1',  '2',  '3',  '4',  '5',  '6',
50 	'7',  '8',  '9',  '0',  '-',  '=', '\b', '\t',	/* 0x00 - 0x0f */
51 	'q',  'w',  'e',  'r',  't',  'y',  'u',  'i',
52 	'o',  'p',  '[',  ']', '\r', 0xff,  'a',  's',  /* 0x10 - 0x1f */
53 	'd',  'f',  'g',  'h',  'j',  'k',  'l',  ';',
54 	'\'',  '`', 0xff, '\\', 'z',  'x',  'c',  'v',	/* 0x20 - 0x2f */
55 	'b',  'n',  'm',  ',' ,  '.', '/', 0xff, 0xff, 0xff,
56 	' ', 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x30 - 0x3f */
57 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  '7',
58 	'8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',	/* 0x40 - 0x4f */
59 	'2',  '3',  '0',  '.', 0xff, 0xff, 0xff, 0xff,
60 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x50 - 0x5F */
61 	'\r', 0xff, 0xff
62 };
63 
64 static unsigned char kbd_shift_xlate[] = {
65 	0xff, 0x1b, '!', '@', '#', '$', '%', '^',
66 	'&', '*', '(', ')', '_', '+', '\b', '\t',	/* 0x00 - 0x0f */
67 	'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I',
68 	'O', 'P', '{', '}', '\r', 0xff, 'A', 'S',	/* 0x10 - 0x1f */
69 	'D', 'F', 'G', 'H', 'J', 'K', 'L', ':',
70 	'"', '~', 0xff, '|', 'Z', 'X', 'C', 'V',	/* 0x20 - 0x2f */
71 	'B', 'N', 'M', '<', '>', '?', 0xff, 0xff, 0xff,
72 	' ', 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x30 - 0x3f */
73 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, '7',
74 	'8', '9', '-', '4', '5', '6', '+', '1',	/* 0x40 - 0x4f */
75 	'2', '3', '0', '.', 0xff, 0xff, 0xff, 0xff, 0xff,
76 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x50 - 0x5F */
77 	'\r', 0xff, 0xff
78 };
79 
80 static unsigned char kbd_ctrl_xlate[] = {
81 	0xff, 0x1b, '1', 0x00, '3', '4', '5', 0x1E,
82 	'7', '8', '9', '0', 0x1F, '=', '\b', '\t',	/* 0x00 - 0x0f */
83 	0x11, 0x17, 0x05, 0x12, 0x14, 0x18, 0x15, 0x09,
84 	0x0f, 0x10, 0x1b, 0x1d, '\n', 0xff, 0x01, 0x13,	/* 0x10 - 0x1f */
85 	0x04, 0x06, 0x08, 0x09, 0x0a, 0x0b, 0x0c, ';',
86 	'\'', '~', 0x00, 0x1c, 0x1a, 0x18, 0x03, 0x16,	/* 0x20 - 0x2f */
87 	0x02, 0x0e, 0x0d, '<', '>', '?', 0xff, 0xff,
88 	0xff, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x30 - 0x3f */
89 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, '7',
90 	'8', '9', '-', '4', '5', '6', '+', '1',		/* 0x40 - 0x4f */
91 	'2', '3', '0', '.', 0xff, 0xff, 0xff, 0xff,
92 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 0x50 - 0x5F */
93 	'\r', 0xff, 0xff
94 };
95 
96 /*
97  * Scan key code to ANSI 3.64 escape sequence table.  This table is
98  * incomplete in that it does not include all possible extra keys.
99  */
100 static struct {
101 	int kbd_scan_code;
102 	char *escape;
103 } kbd_to_ansi364[] = {
104 	{ KEY_UP, "\033[A"},
105 	{ KEY_DOWN, "\033[B"},
106 	{ KEY_RIGHT, "\033[C"},
107 	{ KEY_LEFT, "\033[D"},
108 };
109 
110 /* Maximum number of output characters that an ANSI sequence expands to */
111 #define ANSI_CHAR_MAX	3
112 
113 static int input_queue_ascii(struct input_config *config, int ch)
114 {
115 	if (config->fifo_in + 1 == INPUT_BUFFER_LEN) {
116 		if (!config->fifo_out)
117 			return -1; /* buffer full */
118 		else
119 			config->fifo_in = 0;
120 	} else {
121 		if (config->fifo_in + 1 == config->fifo_out)
122 			return -1; /* buffer full */
123 		config->fifo_in++;
124 	}
125 	config->fifo[config->fifo_in] = (uchar)ch;
126 
127 	return 0;
128 }
129 
130 int input_tstc(struct input_config *config)
131 {
132 	if (config->fifo_in == config->fifo_out && config->read_keys) {
133 		if (!(*config->read_keys)(config))
134 			return 0;
135 	}
136 	return config->fifo_in != config->fifo_out;
137 }
138 
139 int input_getc(struct input_config *config)
140 {
141 	int err = 0;
142 
143 	while (config->fifo_in == config->fifo_out) {
144 		if (config->read_keys)
145 			err = (*config->read_keys)(config);
146 		if (err)
147 			return -1;
148 	}
149 
150 	if (++config->fifo_out == INPUT_BUFFER_LEN)
151 		config->fifo_out = 0;
152 
153 	return config->fifo[config->fifo_out];
154 }
155 
156 /**
157  * Process a modifier/special key press or release and decide which key
158  * translation array should be used as a result.
159  *
160  * TODO: Should keep track of modifier press/release
161  *
162  * @param config	Input state
163  * @param key		Key code to process
164  * @param release	0 if a press, 1 if a release
165  * @return pointer to keycode->ascii translation table that should be used
166  */
167 static struct input_key_xlate *process_modifier(struct input_config *config,
168 						int key, int release)
169 {
170 	struct input_key_xlate *table;
171 	int flip = -1;
172 	int i;
173 
174 	/* Start with the main table, and see what modifiers change it */
175 	assert(config->num_tables > 0);
176 	table = &config->table[0];
177 	for (i = 1; i < config->num_tables; i++) {
178 		struct input_key_xlate *tab = &config->table[i];
179 
180 		if (key == tab->left_keycode || key == tab->right_keycode)
181 			table = tab;
182 	}
183 
184 	/* Handle the lighted keys */
185 	if (!release) {
186 		switch (key) {
187 		case KEY_SCROLLLOCK:
188 			flip = FLAG_SCROLL_LOCK;
189 			break;
190 		case KEY_NUMLOCK:
191 			flip = FLAG_NUM_LOCK;
192 			break;
193 		case KEY_CAPSLOCK:
194 			flip = FLAG_CAPS_LOCK;
195 			break;
196 		}
197 	}
198 
199 	if (flip != -1) {
200 		int leds = 0;
201 
202 		config->leds ^= flip;
203 		if (config->flags & FLAG_NUM_LOCK)
204 			leds |= INPUT_LED_NUM;
205 		if (config->flags & FLAG_CAPS_LOCK)
206 			leds |= INPUT_LED_CAPS;
207 		if (config->flags & FLAG_SCROLL_LOCK)
208 			leds |= INPUT_LED_SCROLL;
209 		config->leds = leds;
210 	}
211 
212 	return table;
213 }
214 
215 /**
216  * Search an int array for a key value
217  *
218  * @param array	Array to search
219  * @param count	Number of elements in array
220  * @param key	Key value to find
221  * @return element where value was first found, -1 if none
222  */
223 static int array_search(int *array, int count, int key)
224 {
225 	int i;
226 
227 	for (i = 0; i < count; i++) {
228 		if (array[i] == key)
229 			return i;
230 	}
231 
232 	return -1;
233 }
234 
235 /**
236  * Sort an array so that those elements that exist in the ordering are
237  * first in the array, and in the same order as the ordering. The algorithm
238  * is O(count * ocount) and designed for small arrays.
239  *
240  * TODO: Move this to common / lib?
241  *
242  * @param dest		Array with elements to sort, also destination array
243  * @param count		Number of elements to sort
244  * @param order		Array containing ordering elements
245  * @param ocount	Number of ordering elements
246  * @return number of elements in dest that are in order (these will be at the
247  *	start of dest).
248  */
249 static int sort_array_by_ordering(int *dest, int count, int *order,
250 				   int ocount)
251 {
252 	int temp[count];
253 	int dest_count;
254 	int same;	/* number of elements which are the same */
255 	int i;
256 
257 	/* setup output items, copy items to be sorted into our temp area */
258 	memcpy(temp, dest, count * sizeof(*dest));
259 	dest_count = 0;
260 
261 	/* work through the ordering, move over the elements we agree on */
262 	for (i = 0; i < ocount; i++) {
263 		if (array_search(temp, count, order[i]) != -1)
264 			dest[dest_count++] = order[i];
265 	}
266 	same = dest_count;
267 
268 	/* now move over the elements that are not in the ordering */
269 	for (i = 0; i < count; i++) {
270 		if (array_search(order, ocount, temp[i]) == -1)
271 			dest[dest_count++] = temp[i];
272 	}
273 	assert(dest_count == count);
274 	return same;
275 }
276 
277 /**
278  * Check a list of key codes against the previous key scan
279  *
280  * Given a list of new key codes, we check how many of these are the same
281  * as last time.
282  *
283  * @param config	Input state
284  * @param keycode	List of key codes to examine
285  * @param num_keycodes	Number of key codes
286  * @param same		Returns number of key codes which are the same
287  */
288 static int input_check_keycodes(struct input_config *config,
289 			   int keycode[], int num_keycodes, int *same)
290 {
291 	/* Select the 'plain' xlate table to start with */
292 	if (!config->num_tables) {
293 		debug("%s: No xlate tables: cannot decode keys\n", __func__);
294 		return -1;
295 	}
296 
297 	/* sort the keycodes into the same order as the previous ones */
298 	*same = sort_array_by_ordering(keycode, num_keycodes,
299 			config->prev_keycodes, config->num_prev_keycodes);
300 
301 	memcpy(config->prev_keycodes, keycode, num_keycodes * sizeof(int));
302 	config->num_prev_keycodes = num_keycodes;
303 
304 	return *same != num_keycodes;
305 }
306 
307 /**
308  * Checks and converts a special key code into ANSI 3.64 escape sequence.
309  *
310  * @param config	Input state
311  * @param keycode	Key code to examine
312  * @param output_ch	Buffer to place output characters into. It should
313  *			be at least ANSI_CHAR_MAX bytes long, to allow for
314  *			an ANSI sequence.
315  * @param max_chars	Maximum number of characters to add to output_ch
316  * @return number of characters output, if the key was converted, otherwise 0.
317  *	This may be larger than max_chars, in which case the overflow
318  *	characters are not output.
319  */
320 static int input_keycode_to_ansi364(struct input_config *config,
321 		int keycode, char output_ch[], int max_chars)
322 {
323 	const char *escape;
324 	int ch_count;
325 	int i;
326 
327 	for (i = ch_count = 0; i < ARRAY_SIZE(kbd_to_ansi364); i++) {
328 		if (keycode != kbd_to_ansi364[i].kbd_scan_code)
329 			continue;
330 		for (escape = kbd_to_ansi364[i].escape; *escape; escape++) {
331 			if (ch_count < max_chars)
332 				output_ch[ch_count] = *escape;
333 			ch_count++;
334 		}
335 		return ch_count;
336 	}
337 
338 	return 0;
339 }
340 
341 /**
342  * Converts and queues a list of key codes in escaped ASCII string form
343  * Convert a list of key codes into ASCII
344  *
345  * You must call input_check_keycodes() before this. It turns the keycode
346  * list into a list of ASCII characters and sends them to the input layer.
347  *
348  * Characters which were seen last time do not generate fresh ASCII output.
349  * The output (calls to queue_ascii) may be longer than num_keycodes, if the
350  * keycode contains special keys that was encoded to longer escaped sequence.
351  *
352  * @param config	Input state
353  * @param keycode	List of key codes to examine
354  * @param num_keycodes	Number of key codes
355  * @param output_ch	Buffer to place output characters into. It should
356  *			be at last ANSI_CHAR_MAX * num_keycodes, to allow for
357  *			ANSI sequences.
358  * @param max_chars	Maximum number of characters to add to output_ch
359  * @param same		Number of key codes which are the same
360  * @return number of characters written into output_ch, or -1 if we would
361  *	exceed max_chars chars.
362  */
363 static int input_keycodes_to_ascii(struct input_config *config,
364 		int keycode[], int num_keycodes, char output_ch[],
365 		int max_chars, int same)
366 {
367 	struct input_key_xlate *table;
368 	int ch_count = 0;
369 	int i;
370 
371 	table = &config->table[0];
372 
373 	/* deal with modifiers first */
374 	for (i = 0; i < num_keycodes; i++) {
375 		int key = keycode[i] & KEY_MASK;
376 
377 		if (key >= table->num_entries || table->xlate[key] == 0xff) {
378 			table = process_modifier(config, key,
379 					keycode[i] & KEY_RELEASE);
380 		}
381 	}
382 
383 	/* Start conversion by looking for the first new keycode (by same). */
384 	for (i = same; i < num_keycodes; i++) {
385 		int key = keycode[i];
386 		int ch = (key < table->num_entries) ? table->xlate[key] : 0xff;
387 
388 		/*
389 		 * For a normal key (with an ASCII value), add it; otherwise
390 		 * translate special key to escape sequence if possible.
391 		 */
392 		if (ch != 0xff) {
393 			if (ch_count < max_chars)
394 				output_ch[ch_count] = (uchar)ch;
395 			ch_count++;
396 		} else {
397 			ch_count += input_keycode_to_ansi364(config, key,
398 						output_ch, max_chars);
399 		}
400 	}
401 
402 	if (ch_count > max_chars) {
403 		debug("%s: Output char buffer overflow size=%d, need=%d\n",
404 		      __func__, max_chars, ch_count);
405 		return -1;
406 	}
407 
408 	/* ok, so return keys */
409 	return ch_count;
410 }
411 
412 int input_send_keycodes(struct input_config *config,
413 			int keycode[], int num_keycodes)
414 {
415 	char ch[num_keycodes * ANSI_CHAR_MAX];
416 	int count, i, same = 0;
417 	int is_repeat = 0;
418 	unsigned delay_ms;
419 
420 	config->modifiers = 0;
421 	if (!input_check_keycodes(config, keycode, num_keycodes, &same)) {
422 		/*
423 		 * Same as last time - is it time for another repeat?
424 		 * TODO(sjg@chromium.org) We drop repeats here and since
425 		 * the caller may not call in again for a while, our
426 		 * auto-repeat speed is not quite correct. We should
427 		 * insert another character if we later realise that we
428 		 * have missed a repeat slot.
429 		 */
430 		is_repeat = config->repeat_rate_ms &&
431 			(int)get_timer(config->next_repeat_ms) >= 0;
432 		if (!is_repeat)
433 			return 0;
434 	}
435 
436 	count = input_keycodes_to_ascii(config, keycode, num_keycodes,
437 					ch, sizeof(ch), is_repeat ? 0 : same);
438 	for (i = 0; i < count; i++)
439 		input_queue_ascii(config, ch[i]);
440 	delay_ms = is_repeat ?
441 			config->repeat_rate_ms :
442 			config->repeat_delay_ms;
443 
444 	config->next_repeat_ms = get_timer(0) + delay_ms;
445 
446 	return count;
447 }
448 
449 int input_add_table(struct input_config *config, int left_keycode,
450 		    int right_keycode, const uchar *xlate, int num_entries)
451 {
452 	struct input_key_xlate *table;
453 
454 	if (config->num_tables == INPUT_MAX_MODIFIERS) {
455 		debug("%s: Too many modifier tables\n", __func__);
456 		return -1;
457 	}
458 
459 	table = &config->table[config->num_tables++];
460 	table->left_keycode = left_keycode;
461 	table->right_keycode = right_keycode;
462 	table->xlate = xlate;
463 	table->num_entries = num_entries;
464 
465 	return 0;
466 }
467 
468 void input_set_delays(struct input_config *config, int repeat_delay_ms,
469 	       int repeat_rate_ms)
470 {
471 	config->repeat_delay_ms = repeat_delay_ms;
472 	config->repeat_rate_ms = repeat_rate_ms;
473 }
474 
475 int input_init(struct input_config *config, int leds)
476 {
477 	memset(config, '\0', sizeof(*config));
478 	config->leds = leds;
479 	if (input_add_table(config, -1, -1,
480 			kbd_plain_xlate, ARRAY_SIZE(kbd_plain_xlate)) ||
481 		input_add_table(config, KEY_LEFTSHIFT, KEY_RIGHTSHIFT,
482 			kbd_shift_xlate, ARRAY_SIZE(kbd_shift_xlate)) ||
483 		input_add_table(config, KEY_LEFTCTRL, KEY_RIGHTCTRL,
484 			kbd_ctrl_xlate, ARRAY_SIZE(kbd_ctrl_xlate))) {
485 		debug("%s: Could not add modifier tables\n", __func__);
486 		return -1;
487 	}
488 
489 	return 0;
490 }
491 
492 int input_stdio_register(struct stdio_dev *dev)
493 {
494 	int error;
495 
496 	error = stdio_register(dev);
497 
498 	/* check if this is the standard input device */
499 	if (!error && strcmp(getenv("stdin"), dev->name) == 0) {
500 		/* reassign the console */
501 		if (OVERWRITE_CONSOLE ||
502 				console_assign(stdin, dev->name))
503 			return -1;
504 	}
505 
506 	return 0;
507 }
508