Commit | Line | Data |
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351f683b | 1 | // SPDX-License-Identifier: GPL-2.0+ |
39f8ea46 GU |
2 | /* |
3 | * Character LCD driver for Linux | |
4 | * | |
5 | * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu> | |
6 | * Copyright (C) 2016-2017 Glider bvba | |
39f8ea46 GU |
7 | */ |
8 | ||
9 | #include <linux/atomic.h> | |
b34050fa | 10 | #include <linux/ctype.h> |
39f8ea46 GU |
11 | #include <linux/delay.h> |
12 | #include <linux/fs.h> | |
13 | #include <linux/miscdevice.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/notifier.h> | |
16 | #include <linux/reboot.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/uaccess.h> | |
19 | #include <linux/workqueue.h> | |
20 | ||
21 | #include <generated/utsrelease.h> | |
22 | ||
75354284 | 23 | #include "charlcd.h" |
39f8ea46 | 24 | |
39f8ea46 GU |
25 | #define DEFAULT_LCD_BWIDTH 40 |
26 | #define DEFAULT_LCD_HWIDTH 64 | |
27 | ||
28 | /* Keep the backlight on this many seconds for each flash */ | |
29 | #define LCD_BL_TEMPO_PERIOD 4 | |
30 | ||
31 | #define LCD_FLAG_B 0x0004 /* Blink on */ | |
32 | #define LCD_FLAG_C 0x0008 /* Cursor on */ | |
33 | #define LCD_FLAG_D 0x0010 /* Display on */ | |
34 | #define LCD_FLAG_F 0x0020 /* Large font mode */ | |
35 | #define LCD_FLAG_N 0x0040 /* 2-rows mode */ | |
36 | #define LCD_FLAG_L 0x0080 /* Backlight enabled */ | |
37 | ||
38 | /* LCD commands */ | |
39 | #define LCD_CMD_DISPLAY_CLEAR 0x01 /* Clear entire display */ | |
40 | ||
41 | #define LCD_CMD_ENTRY_MODE 0x04 /* Set entry mode */ | |
42 | #define LCD_CMD_CURSOR_INC 0x02 /* Increment cursor */ | |
43 | ||
44 | #define LCD_CMD_DISPLAY_CTRL 0x08 /* Display control */ | |
45 | #define LCD_CMD_DISPLAY_ON 0x04 /* Set display on */ | |
46 | #define LCD_CMD_CURSOR_ON 0x02 /* Set cursor on */ | |
47 | #define LCD_CMD_BLINK_ON 0x01 /* Set blink on */ | |
48 | ||
49 | #define LCD_CMD_SHIFT 0x10 /* Shift cursor/display */ | |
50 | #define LCD_CMD_DISPLAY_SHIFT 0x08 /* Shift display instead of cursor */ | |
51 | #define LCD_CMD_SHIFT_RIGHT 0x04 /* Shift display/cursor to the right */ | |
52 | ||
53 | #define LCD_CMD_FUNCTION_SET 0x20 /* Set function */ | |
54 | #define LCD_CMD_DATA_LEN_8BITS 0x10 /* Set data length to 8 bits */ | |
55 | #define LCD_CMD_TWO_LINES 0x08 /* Set to two display lines */ | |
56 | #define LCD_CMD_FONT_5X10_DOTS 0x04 /* Set char font to 5x10 dots */ | |
57 | ||
58 | #define LCD_CMD_SET_CGRAM_ADDR 0x40 /* Set char generator RAM address */ | |
59 | ||
60 | #define LCD_CMD_SET_DDRAM_ADDR 0x80 /* Set display data RAM address */ | |
61 | ||
62 | #define LCD_ESCAPE_LEN 24 /* Max chars for LCD escape command */ | |
63 | #define LCD_ESCAPE_CHAR 27 /* Use char 27 for escape command */ | |
64 | ||
65 | struct charlcd_priv { | |
66 | struct charlcd lcd; | |
67 | ||
68 | struct delayed_work bl_work; | |
69 | struct mutex bl_tempo_lock; /* Protects access to bl_tempo */ | |
70 | bool bl_tempo; | |
71 | ||
72 | bool must_clear; | |
73 | ||
74 | /* contains the LCD config state */ | |
75 | unsigned long int flags; | |
76 | ||
77 | /* Contains the LCD X and Y offset */ | |
78 | struct { | |
79 | unsigned long int x; | |
80 | unsigned long int y; | |
81 | } addr; | |
82 | ||
83 | /* Current escape sequence and it's length or -1 if outside */ | |
84 | struct { | |
85 | char buf[LCD_ESCAPE_LEN + 1]; | |
86 | int len; | |
87 | } esc_seq; | |
88 | ||
2f920c0f | 89 | unsigned long long drvdata[]; |
39f8ea46 GU |
90 | }; |
91 | ||
b658a211 | 92 | #define charlcd_to_priv(p) container_of(p, struct charlcd_priv, lcd) |
39f8ea46 GU |
93 | |
94 | /* Device single-open policy control */ | |
95 | static atomic_t charlcd_available = ATOMIC_INIT(1); | |
96 | ||
97 | /* sleeps that many milliseconds with a reschedule */ | |
98 | static void long_sleep(int ms) | |
99 | { | |
17161392 | 100 | schedule_timeout_interruptible(msecs_to_jiffies(ms)); |
39f8ea46 GU |
101 | } |
102 | ||
103 | /* turn the backlight on or off */ | |
104 | static void charlcd_backlight(struct charlcd *lcd, int on) | |
105 | { | |
b658a211 | 106 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
107 | |
108 | if (!lcd->ops->backlight) | |
109 | return; | |
110 | ||
111 | mutex_lock(&priv->bl_tempo_lock); | |
112 | if (!priv->bl_tempo) | |
113 | lcd->ops->backlight(lcd, on); | |
114 | mutex_unlock(&priv->bl_tempo_lock); | |
115 | } | |
116 | ||
117 | static void charlcd_bl_off(struct work_struct *work) | |
118 | { | |
119 | struct delayed_work *dwork = to_delayed_work(work); | |
120 | struct charlcd_priv *priv = | |
121 | container_of(dwork, struct charlcd_priv, bl_work); | |
122 | ||
123 | mutex_lock(&priv->bl_tempo_lock); | |
124 | if (priv->bl_tempo) { | |
125 | priv->bl_tempo = false; | |
126 | if (!(priv->flags & LCD_FLAG_L)) | |
127 | priv->lcd.ops->backlight(&priv->lcd, 0); | |
128 | } | |
129 | mutex_unlock(&priv->bl_tempo_lock); | |
130 | } | |
131 | ||
132 | /* turn the backlight on for a little while */ | |
133 | void charlcd_poke(struct charlcd *lcd) | |
134 | { | |
b658a211 | 135 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
136 | |
137 | if (!lcd->ops->backlight) | |
138 | return; | |
139 | ||
140 | cancel_delayed_work_sync(&priv->bl_work); | |
141 | ||
142 | mutex_lock(&priv->bl_tempo_lock); | |
143 | if (!priv->bl_tempo && !(priv->flags & LCD_FLAG_L)) | |
144 | lcd->ops->backlight(lcd, 1); | |
145 | priv->bl_tempo = true; | |
146 | schedule_delayed_work(&priv->bl_work, LCD_BL_TEMPO_PERIOD * HZ); | |
147 | mutex_unlock(&priv->bl_tempo_lock); | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(charlcd_poke); | |
150 | ||
151 | static void charlcd_gotoxy(struct charlcd *lcd) | |
152 | { | |
b658a211 | 153 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
1d3b2af2 GU |
154 | unsigned int addr; |
155 | ||
156 | /* | |
157 | * we force the cursor to stay at the end of the | |
158 | * line if it wants to go farther | |
159 | */ | |
160 | addr = priv->addr.x < lcd->bwidth ? priv->addr.x & (lcd->hwidth - 1) | |
161 | : lcd->bwidth - 1; | |
162 | if (priv->addr.y & 1) | |
163 | addr += lcd->hwidth; | |
164 | if (priv->addr.y & 2) | |
165 | addr += lcd->bwidth; | |
166 | lcd->ops->write_cmd(lcd, LCD_CMD_SET_DDRAM_ADDR | addr); | |
39f8ea46 GU |
167 | } |
168 | ||
169 | static void charlcd_home(struct charlcd *lcd) | |
170 | { | |
b658a211 | 171 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
172 | |
173 | priv->addr.x = 0; | |
174 | priv->addr.y = 0; | |
175 | charlcd_gotoxy(lcd); | |
176 | } | |
177 | ||
178 | static void charlcd_print(struct charlcd *lcd, char c) | |
179 | { | |
b658a211 | 180 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
181 | |
182 | if (priv->addr.x < lcd->bwidth) { | |
183 | if (lcd->char_conv) | |
184 | c = lcd->char_conv[(unsigned char)c]; | |
185 | lcd->ops->write_data(lcd, c); | |
186 | priv->addr.x++; | |
54bc937f SY |
187 | |
188 | /* prevents the cursor from wrapping onto the next line */ | |
189 | if (priv->addr.x == lcd->bwidth) | |
190 | charlcd_gotoxy(lcd); | |
39f8ea46 | 191 | } |
39f8ea46 GU |
192 | } |
193 | ||
194 | static void charlcd_clear_fast(struct charlcd *lcd) | |
195 | { | |
196 | int pos; | |
197 | ||
198 | charlcd_home(lcd); | |
199 | ||
200 | if (lcd->ops->clear_fast) | |
201 | lcd->ops->clear_fast(lcd); | |
202 | else | |
1d3b2af2 | 203 | for (pos = 0; pos < min(2, lcd->height) * lcd->hwidth; pos++) |
39f8ea46 GU |
204 | lcd->ops->write_data(lcd, ' '); |
205 | ||
206 | charlcd_home(lcd); | |
207 | } | |
208 | ||
209 | /* clears the display and resets X/Y */ | |
210 | static void charlcd_clear_display(struct charlcd *lcd) | |
211 | { | |
b658a211 | 212 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
213 | |
214 | lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CLEAR); | |
215 | priv->addr.x = 0; | |
216 | priv->addr.y = 0; | |
217 | /* we must wait a few milliseconds (15) */ | |
218 | long_sleep(15); | |
219 | } | |
220 | ||
221 | static int charlcd_init_display(struct charlcd *lcd) | |
222 | { | |
ac201479 | 223 | void (*write_cmd_raw)(struct charlcd *lcd, int cmd); |
b658a211 | 224 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
ac201479 GU |
225 | u8 init; |
226 | ||
227 | if (lcd->ifwidth != 4 && lcd->ifwidth != 8) | |
228 | return -EINVAL; | |
39f8ea46 GU |
229 | |
230 | priv->flags = ((lcd->height > 1) ? LCD_FLAG_N : 0) | LCD_FLAG_D | | |
231 | LCD_FLAG_C | LCD_FLAG_B; | |
232 | ||
233 | long_sleep(20); /* wait 20 ms after power-up for the paranoid */ | |
234 | ||
ac201479 GU |
235 | /* |
236 | * 8-bit mode, 1 line, small fonts; let's do it 3 times, to make sure | |
237 | * the LCD is in 8-bit mode afterwards | |
238 | */ | |
239 | init = LCD_CMD_FUNCTION_SET | LCD_CMD_DATA_LEN_8BITS; | |
240 | if (lcd->ifwidth == 4) { | |
241 | init >>= 4; | |
242 | write_cmd_raw = lcd->ops->write_cmd_raw4; | |
243 | } else { | |
244 | write_cmd_raw = lcd->ops->write_cmd; | |
245 | } | |
246 | write_cmd_raw(lcd, init); | |
39f8ea46 | 247 | long_sleep(10); |
ac201479 | 248 | write_cmd_raw(lcd, init); |
39f8ea46 | 249 | long_sleep(10); |
ac201479 | 250 | write_cmd_raw(lcd, init); |
39f8ea46 GU |
251 | long_sleep(10); |
252 | ||
ac201479 GU |
253 | if (lcd->ifwidth == 4) { |
254 | /* Switch to 4-bit mode, 1 line, small fonts */ | |
255 | lcd->ops->write_cmd_raw4(lcd, LCD_CMD_FUNCTION_SET >> 4); | |
256 | long_sleep(10); | |
257 | } | |
258 | ||
39f8ea46 GU |
259 | /* set font height and lines number */ |
260 | lcd->ops->write_cmd(lcd, | |
ac201479 GU |
261 | LCD_CMD_FUNCTION_SET | |
262 | ((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) | | |
39f8ea46 GU |
263 | ((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) | |
264 | ((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0)); | |
265 | long_sleep(10); | |
266 | ||
267 | /* display off, cursor off, blink off */ | |
268 | lcd->ops->write_cmd(lcd, LCD_CMD_DISPLAY_CTRL); | |
269 | long_sleep(10); | |
270 | ||
271 | lcd->ops->write_cmd(lcd, | |
272 | LCD_CMD_DISPLAY_CTRL | /* set display mode */ | |
273 | ((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) | | |
274 | ((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) | | |
275 | ((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0)); | |
276 | ||
277 | charlcd_backlight(lcd, (priv->flags & LCD_FLAG_L) ? 1 : 0); | |
278 | ||
279 | long_sleep(10); | |
280 | ||
281 | /* entry mode set : increment, cursor shifting */ | |
282 | lcd->ops->write_cmd(lcd, LCD_CMD_ENTRY_MODE | LCD_CMD_CURSOR_INC); | |
283 | ||
284 | charlcd_clear_display(lcd); | |
285 | return 0; | |
286 | } | |
287 | ||
b34050fa MO |
288 | /* |
289 | * Parses a movement command of the form "(.*);", where the group can be | |
290 | * any number of subcommands of the form "(x|y)[0-9]+". | |
291 | * | |
292 | * Returns whether the command is valid. The position arguments are | |
293 | * only written if the parsing was successful. | |
294 | * | |
295 | * For instance: | |
296 | * - ";" returns (<original x>, <original y>). | |
297 | * - "x1;" returns (1, <original y>). | |
298 | * - "y2x1;" returns (1, 2). | |
299 | * - "x12y34x56;" returns (56, 34). | |
300 | * - "" fails. | |
301 | * - "x" fails. | |
302 | * - "x;" fails. | |
303 | * - "x1" fails. | |
304 | * - "xy12;" fails. | |
305 | * - "x12yy12;" fails. | |
306 | * - "xx" fails. | |
307 | */ | |
308 | static bool parse_xy(const char *s, unsigned long *x, unsigned long *y) | |
309 | { | |
310 | unsigned long new_x = *x; | |
311 | unsigned long new_y = *y; | |
d717e7da | 312 | char *p; |
b34050fa MO |
313 | |
314 | for (;;) { | |
315 | if (!*s) | |
316 | return false; | |
317 | ||
318 | if (*s == ';') | |
319 | break; | |
320 | ||
321 | if (*s == 'x') { | |
d717e7da AS |
322 | new_x = simple_strtoul(s + 1, &p, 10); |
323 | if (p == s + 1) | |
b34050fa | 324 | return false; |
d717e7da | 325 | s = p; |
b34050fa | 326 | } else if (*s == 'y') { |
d717e7da AS |
327 | new_y = simple_strtoul(s + 1, &p, 10); |
328 | if (p == s + 1) | |
b34050fa | 329 | return false; |
d717e7da | 330 | s = p; |
b34050fa MO |
331 | } else { |
332 | return false; | |
333 | } | |
334 | } | |
335 | ||
336 | *x = new_x; | |
337 | *y = new_y; | |
338 | return true; | |
339 | } | |
340 | ||
39f8ea46 GU |
341 | /* |
342 | * These are the file operation function for user access to /dev/lcd | |
343 | * This function can also be called from inside the kernel, by | |
344 | * setting file and ppos to NULL. | |
345 | * | |
346 | */ | |
347 | ||
348 | static inline int handle_lcd_special_code(struct charlcd *lcd) | |
349 | { | |
b658a211 | 350 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
351 | |
352 | /* LCD special codes */ | |
353 | ||
354 | int processed = 0; | |
355 | ||
356 | char *esc = priv->esc_seq.buf + 2; | |
357 | int oldflags = priv->flags; | |
358 | ||
359 | /* check for display mode flags */ | |
360 | switch (*esc) { | |
361 | case 'D': /* Display ON */ | |
362 | priv->flags |= LCD_FLAG_D; | |
363 | processed = 1; | |
364 | break; | |
365 | case 'd': /* Display OFF */ | |
366 | priv->flags &= ~LCD_FLAG_D; | |
367 | processed = 1; | |
368 | break; | |
369 | case 'C': /* Cursor ON */ | |
370 | priv->flags |= LCD_FLAG_C; | |
371 | processed = 1; | |
372 | break; | |
373 | case 'c': /* Cursor OFF */ | |
374 | priv->flags &= ~LCD_FLAG_C; | |
375 | processed = 1; | |
376 | break; | |
377 | case 'B': /* Blink ON */ | |
378 | priv->flags |= LCD_FLAG_B; | |
379 | processed = 1; | |
380 | break; | |
381 | case 'b': /* Blink OFF */ | |
382 | priv->flags &= ~LCD_FLAG_B; | |
383 | processed = 1; | |
384 | break; | |
385 | case '+': /* Back light ON */ | |
386 | priv->flags |= LCD_FLAG_L; | |
387 | processed = 1; | |
388 | break; | |
389 | case '-': /* Back light OFF */ | |
390 | priv->flags &= ~LCD_FLAG_L; | |
391 | processed = 1; | |
392 | break; | |
393 | case '*': /* Flash back light */ | |
394 | charlcd_poke(lcd); | |
395 | processed = 1; | |
396 | break; | |
397 | case 'f': /* Small Font */ | |
398 | priv->flags &= ~LCD_FLAG_F; | |
399 | processed = 1; | |
400 | break; | |
401 | case 'F': /* Large Font */ | |
402 | priv->flags |= LCD_FLAG_F; | |
403 | processed = 1; | |
404 | break; | |
405 | case 'n': /* One Line */ | |
406 | priv->flags &= ~LCD_FLAG_N; | |
407 | processed = 1; | |
408 | break; | |
409 | case 'N': /* Two Lines */ | |
410 | priv->flags |= LCD_FLAG_N; | |
99b9b490 | 411 | processed = 1; |
39f8ea46 GU |
412 | break; |
413 | case 'l': /* Shift Cursor Left */ | |
414 | if (priv->addr.x > 0) { | |
415 | /* back one char if not at end of line */ | |
416 | if (priv->addr.x < lcd->bwidth) | |
417 | lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); | |
418 | priv->addr.x--; | |
419 | } | |
420 | processed = 1; | |
421 | break; | |
422 | case 'r': /* shift cursor right */ | |
423 | if (priv->addr.x < lcd->width) { | |
424 | /* allow the cursor to pass the end of the line */ | |
425 | if (priv->addr.x < (lcd->bwidth - 1)) | |
426 | lcd->ops->write_cmd(lcd, | |
427 | LCD_CMD_SHIFT | LCD_CMD_SHIFT_RIGHT); | |
428 | priv->addr.x++; | |
429 | } | |
430 | processed = 1; | |
431 | break; | |
432 | case 'L': /* shift display left */ | |
433 | lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT); | |
434 | processed = 1; | |
435 | break; | |
436 | case 'R': /* shift display right */ | |
437 | lcd->ops->write_cmd(lcd, | |
438 | LCD_CMD_SHIFT | LCD_CMD_DISPLAY_SHIFT | | |
439 | LCD_CMD_SHIFT_RIGHT); | |
440 | processed = 1; | |
441 | break; | |
442 | case 'k': { /* kill end of line */ | |
443 | int x; | |
444 | ||
445 | for (x = priv->addr.x; x < lcd->bwidth; x++) | |
446 | lcd->ops->write_data(lcd, ' '); | |
447 | ||
448 | /* restore cursor position */ | |
449 | charlcd_gotoxy(lcd); | |
450 | processed = 1; | |
451 | break; | |
452 | } | |
453 | case 'I': /* reinitialize display */ | |
454 | charlcd_init_display(lcd); | |
455 | processed = 1; | |
456 | break; | |
457 | case 'G': { | |
458 | /* Generator : LGcxxxxx...xx; must have <c> between '0' | |
459 | * and '7', representing the numerical ASCII code of the | |
460 | * redefined character, and <xx...xx> a sequence of 16 | |
461 | * hex digits representing 8 bytes for each character. | |
462 | * Most LCDs will only use 5 lower bits of the 7 first | |
463 | * bytes. | |
464 | */ | |
465 | ||
466 | unsigned char cgbytes[8]; | |
467 | unsigned char cgaddr; | |
468 | int cgoffset; | |
469 | int shift; | |
470 | char value; | |
471 | int addr; | |
472 | ||
473 | if (!strchr(esc, ';')) | |
474 | break; | |
475 | ||
476 | esc++; | |
477 | ||
478 | cgaddr = *(esc++) - '0'; | |
479 | if (cgaddr > 7) { | |
480 | processed = 1; | |
481 | break; | |
482 | } | |
483 | ||
484 | cgoffset = 0; | |
485 | shift = 0; | |
486 | value = 0; | |
487 | while (*esc && cgoffset < 8) { | |
3f03b649 AS |
488 | int half; |
489 | ||
39f8ea46 | 490 | shift ^= 4; |
3f03b649 AS |
491 | |
492 | half = hex_to_bin(*esc++); | |
493 | if (half < 0) | |
39f8ea46 | 494 | continue; |
39f8ea46 | 495 | |
3f03b649 | 496 | value |= half << shift; |
39f8ea46 GU |
497 | if (shift == 0) { |
498 | cgbytes[cgoffset++] = value; | |
499 | value = 0; | |
500 | } | |
39f8ea46 GU |
501 | } |
502 | ||
503 | lcd->ops->write_cmd(lcd, LCD_CMD_SET_CGRAM_ADDR | (cgaddr * 8)); | |
504 | for (addr = 0; addr < cgoffset; addr++) | |
505 | lcd->ops->write_data(lcd, cgbytes[addr]); | |
506 | ||
507 | /* ensures that we stop writing to CGRAM */ | |
508 | charlcd_gotoxy(lcd); | |
509 | processed = 1; | |
510 | break; | |
511 | } | |
512 | case 'x': /* gotoxy : LxXXX[yYYY]; */ | |
513 | case 'y': /* gotoxy : LyYYY[xXXX]; */ | |
9bc30ab8 MR |
514 | if (priv->esc_seq.buf[priv->esc_seq.len - 1] != ';') |
515 | break; | |
516 | ||
b34050fa MO |
517 | /* If the command is valid, move to the new address */ |
518 | if (parse_xy(esc, &priv->addr.x, &priv->addr.y)) | |
519 | charlcd_gotoxy(lcd); | |
39f8ea46 | 520 | |
b34050fa | 521 | /* Regardless of its validity, mark as processed */ |
39f8ea46 GU |
522 | processed = 1; |
523 | break; | |
524 | } | |
525 | ||
526 | /* TODO: This indent party here got ugly, clean it! */ | |
527 | /* Check whether one flag was changed */ | |
528 | if (oldflags == priv->flags) | |
529 | return processed; | |
530 | ||
531 | /* check whether one of B,C,D flags were changed */ | |
532 | if ((oldflags ^ priv->flags) & | |
533 | (LCD_FLAG_B | LCD_FLAG_C | LCD_FLAG_D)) | |
534 | /* set display mode */ | |
535 | lcd->ops->write_cmd(lcd, | |
536 | LCD_CMD_DISPLAY_CTRL | | |
537 | ((priv->flags & LCD_FLAG_D) ? LCD_CMD_DISPLAY_ON : 0) | | |
538 | ((priv->flags & LCD_FLAG_C) ? LCD_CMD_CURSOR_ON : 0) | | |
539 | ((priv->flags & LCD_FLAG_B) ? LCD_CMD_BLINK_ON : 0)); | |
540 | /* check whether one of F,N flags was changed */ | |
541 | else if ((oldflags ^ priv->flags) & (LCD_FLAG_F | LCD_FLAG_N)) | |
542 | lcd->ops->write_cmd(lcd, | |
ac201479 GU |
543 | LCD_CMD_FUNCTION_SET | |
544 | ((lcd->ifwidth == 8) ? LCD_CMD_DATA_LEN_8BITS : 0) | | |
39f8ea46 GU |
545 | ((priv->flags & LCD_FLAG_F) ? LCD_CMD_FONT_5X10_DOTS : 0) | |
546 | ((priv->flags & LCD_FLAG_N) ? LCD_CMD_TWO_LINES : 0)); | |
547 | /* check whether L flag was changed */ | |
548 | else if ((oldflags ^ priv->flags) & LCD_FLAG_L) | |
549 | charlcd_backlight(lcd, !!(priv->flags & LCD_FLAG_L)); | |
550 | ||
551 | return processed; | |
552 | } | |
553 | ||
554 | static void charlcd_write_char(struct charlcd *lcd, char c) | |
555 | { | |
b658a211 | 556 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
557 | |
558 | /* first, we'll test if we're in escape mode */ | |
559 | if ((c != '\n') && priv->esc_seq.len >= 0) { | |
560 | /* yes, let's add this char to the buffer */ | |
561 | priv->esc_seq.buf[priv->esc_seq.len++] = c; | |
8c483758 | 562 | priv->esc_seq.buf[priv->esc_seq.len] = '\0'; |
39f8ea46 GU |
563 | } else { |
564 | /* aborts any previous escape sequence */ | |
565 | priv->esc_seq.len = -1; | |
566 | ||
567 | switch (c) { | |
568 | case LCD_ESCAPE_CHAR: | |
569 | /* start of an escape sequence */ | |
570 | priv->esc_seq.len = 0; | |
8c483758 | 571 | priv->esc_seq.buf[priv->esc_seq.len] = '\0'; |
39f8ea46 GU |
572 | break; |
573 | case '\b': | |
574 | /* go back one char and clear it */ | |
575 | if (priv->addr.x > 0) { | |
576 | /* | |
577 | * check if we're not at the | |
578 | * end of the line | |
579 | */ | |
580 | if (priv->addr.x < lcd->bwidth) | |
581 | /* back one char */ | |
582 | lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); | |
583 | priv->addr.x--; | |
584 | } | |
585 | /* replace with a space */ | |
586 | lcd->ops->write_data(lcd, ' '); | |
587 | /* back one char again */ | |
588 | lcd->ops->write_cmd(lcd, LCD_CMD_SHIFT); | |
589 | break; | |
9629ccca | 590 | case '\f': |
39f8ea46 GU |
591 | /* quickly clear the display */ |
592 | charlcd_clear_fast(lcd); | |
593 | break; | |
594 | case '\n': | |
595 | /* | |
596 | * flush the remainder of the current line and | |
597 | * go to the beginning of the next line | |
598 | */ | |
599 | for (; priv->addr.x < lcd->bwidth; priv->addr.x++) | |
600 | lcd->ops->write_data(lcd, ' '); | |
601 | priv->addr.x = 0; | |
602 | priv->addr.y = (priv->addr.y + 1) % lcd->height; | |
603 | charlcd_gotoxy(lcd); | |
604 | break; | |
605 | case '\r': | |
606 | /* go to the beginning of the same line */ | |
607 | priv->addr.x = 0; | |
608 | charlcd_gotoxy(lcd); | |
609 | break; | |
610 | case '\t': | |
611 | /* print a space instead of the tab */ | |
612 | charlcd_print(lcd, ' '); | |
613 | break; | |
614 | default: | |
615 | /* simply print this char */ | |
616 | charlcd_print(lcd, c); | |
617 | break; | |
618 | } | |
619 | } | |
620 | ||
621 | /* | |
622 | * now we'll see if we're in an escape mode and if the current | |
623 | * escape sequence can be understood. | |
624 | */ | |
625 | if (priv->esc_seq.len >= 2) { | |
626 | int processed = 0; | |
627 | ||
628 | if (!strcmp(priv->esc_seq.buf, "[2J")) { | |
629 | /* clear the display */ | |
630 | charlcd_clear_fast(lcd); | |
631 | processed = 1; | |
632 | } else if (!strcmp(priv->esc_seq.buf, "[H")) { | |
633 | /* cursor to home */ | |
634 | charlcd_home(lcd); | |
635 | processed = 1; | |
636 | } | |
637 | /* codes starting with ^[[L */ | |
638 | else if ((priv->esc_seq.len >= 3) && | |
639 | (priv->esc_seq.buf[0] == '[') && | |
640 | (priv->esc_seq.buf[1] == 'L')) { | |
641 | processed = handle_lcd_special_code(lcd); | |
642 | } | |
643 | ||
644 | /* LCD special escape codes */ | |
645 | /* | |
646 | * flush the escape sequence if it's been processed | |
647 | * or if it is getting too long. | |
648 | */ | |
649 | if (processed || (priv->esc_seq.len >= LCD_ESCAPE_LEN)) | |
650 | priv->esc_seq.len = -1; | |
651 | } /* escape codes */ | |
652 | } | |
653 | ||
654 | static struct charlcd *the_charlcd; | |
655 | ||
656 | static ssize_t charlcd_write(struct file *file, const char __user *buf, | |
657 | size_t count, loff_t *ppos) | |
658 | { | |
659 | const char __user *tmp = buf; | |
660 | char c; | |
661 | ||
662 | for (; count-- > 0; (*ppos)++, tmp++) { | |
663 | if (!in_interrupt() && (((count + 1) & 0x1f) == 0)) | |
664 | /* | |
665 | * let's be a little nice with other processes | |
666 | * that need some CPU | |
667 | */ | |
668 | schedule(); | |
669 | ||
670 | if (get_user(c, tmp)) | |
671 | return -EFAULT; | |
672 | ||
673 | charlcd_write_char(the_charlcd, c); | |
674 | } | |
675 | ||
676 | return tmp - buf; | |
677 | } | |
678 | ||
679 | static int charlcd_open(struct inode *inode, struct file *file) | |
680 | { | |
b658a211 | 681 | struct charlcd_priv *priv = charlcd_to_priv(the_charlcd); |
93dc1774 | 682 | int ret; |
39f8ea46 | 683 | |
93dc1774 | 684 | ret = -EBUSY; |
39f8ea46 | 685 | if (!atomic_dec_and_test(&charlcd_available)) |
93dc1774 | 686 | goto fail; /* open only once at a time */ |
39f8ea46 | 687 | |
93dc1774 | 688 | ret = -EPERM; |
39f8ea46 | 689 | if (file->f_mode & FMODE_READ) /* device is write-only */ |
93dc1774 | 690 | goto fail; |
39f8ea46 GU |
691 | |
692 | if (priv->must_clear) { | |
693 | charlcd_clear_display(&priv->lcd); | |
694 | priv->must_clear = false; | |
695 | } | |
696 | return nonseekable_open(inode, file); | |
93dc1774 WT |
697 | |
698 | fail: | |
699 | atomic_inc(&charlcd_available); | |
700 | return ret; | |
39f8ea46 GU |
701 | } |
702 | ||
703 | static int charlcd_release(struct inode *inode, struct file *file) | |
704 | { | |
705 | atomic_inc(&charlcd_available); | |
706 | return 0; | |
707 | } | |
708 | ||
709 | static const struct file_operations charlcd_fops = { | |
710 | .write = charlcd_write, | |
711 | .open = charlcd_open, | |
712 | .release = charlcd_release, | |
713 | .llseek = no_llseek, | |
714 | }; | |
715 | ||
716 | static struct miscdevice charlcd_dev = { | |
717 | .minor = LCD_MINOR, | |
718 | .name = "lcd", | |
719 | .fops = &charlcd_fops, | |
720 | }; | |
721 | ||
722 | static void charlcd_puts(struct charlcd *lcd, const char *s) | |
723 | { | |
724 | const char *tmp = s; | |
725 | int count = strlen(s); | |
726 | ||
727 | for (; count-- > 0; tmp++) { | |
728 | if (!in_interrupt() && (((count + 1) & 0x1f) == 0)) | |
729 | /* | |
730 | * let's be a little nice with other processes | |
731 | * that need some CPU | |
732 | */ | |
733 | schedule(); | |
734 | ||
735 | charlcd_write_char(lcd, *tmp); | |
736 | } | |
737 | } | |
738 | ||
c9171722 MR |
739 | #ifdef CONFIG_PANEL_BOOT_MESSAGE |
740 | #define LCD_INIT_TEXT CONFIG_PANEL_BOOT_MESSAGE | |
741 | #else | |
742 | #define LCD_INIT_TEXT "Linux-" UTS_RELEASE "\n" | |
743 | #endif | |
744 | ||
cc5d04d8 MR |
745 | #ifdef CONFIG_CHARLCD_BL_ON |
746 | #define LCD_INIT_BL "\x1b[L+" | |
747 | #elif defined(CONFIG_CHARLCD_BL_FLASH) | |
748 | #define LCD_INIT_BL "\x1b[L*" | |
749 | #else | |
750 | #define LCD_INIT_BL "\x1b[L-" | |
751 | #endif | |
752 | ||
39f8ea46 GU |
753 | /* initialize the LCD driver */ |
754 | static int charlcd_init(struct charlcd *lcd) | |
755 | { | |
b658a211 | 756 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
757 | int ret; |
758 | ||
759 | if (lcd->ops->backlight) { | |
760 | mutex_init(&priv->bl_tempo_lock); | |
761 | INIT_DELAYED_WORK(&priv->bl_work, charlcd_bl_off); | |
762 | } | |
763 | ||
764 | /* | |
765 | * before this line, we must NOT send anything to the display. | |
766 | * Since charlcd_init_display() needs to write data, we have to | |
767 | * enable mark the LCD initialized just before. | |
768 | */ | |
769 | ret = charlcd_init_display(lcd); | |
770 | if (ret) | |
771 | return ret; | |
772 | ||
773 | /* display a short message */ | |
cc5d04d8 | 774 | charlcd_puts(lcd, "\x1b[Lc\x1b[Lb" LCD_INIT_BL LCD_INIT_TEXT); |
c9171722 | 775 | |
39f8ea46 GU |
776 | /* clear the display on the next device opening */ |
777 | priv->must_clear = true; | |
778 | charlcd_home(lcd); | |
779 | return 0; | |
780 | } | |
781 | ||
782 | struct charlcd *charlcd_alloc(unsigned int drvdata_size) | |
783 | { | |
784 | struct charlcd_priv *priv; | |
785 | struct charlcd *lcd; | |
786 | ||
787 | priv = kzalloc(sizeof(*priv) + drvdata_size, GFP_KERNEL); | |
788 | if (!priv) | |
789 | return NULL; | |
790 | ||
791 | priv->esc_seq.len = -1; | |
792 | ||
793 | lcd = &priv->lcd; | |
ac201479 | 794 | lcd->ifwidth = 8; |
39f8ea46 GU |
795 | lcd->bwidth = DEFAULT_LCD_BWIDTH; |
796 | lcd->hwidth = DEFAULT_LCD_HWIDTH; | |
797 | lcd->drvdata = priv->drvdata; | |
798 | ||
799 | return lcd; | |
800 | } | |
801 | EXPORT_SYMBOL_GPL(charlcd_alloc); | |
802 | ||
8e44fc85 AS |
803 | void charlcd_free(struct charlcd *lcd) |
804 | { | |
805 | kfree(charlcd_to_priv(lcd)); | |
806 | } | |
807 | EXPORT_SYMBOL_GPL(charlcd_free); | |
808 | ||
39f8ea46 GU |
809 | static int panel_notify_sys(struct notifier_block *this, unsigned long code, |
810 | void *unused) | |
811 | { | |
812 | struct charlcd *lcd = the_charlcd; | |
813 | ||
814 | switch (code) { | |
815 | case SYS_DOWN: | |
816 | charlcd_puts(lcd, | |
817 | "\x0cReloading\nSystem...\x1b[Lc\x1b[Lb\x1b[L+"); | |
818 | break; | |
819 | case SYS_HALT: | |
820 | charlcd_puts(lcd, "\x0cSystem Halted.\x1b[Lc\x1b[Lb\x1b[L+"); | |
821 | break; | |
822 | case SYS_POWER_OFF: | |
823 | charlcd_puts(lcd, "\x0cPower off.\x1b[Lc\x1b[Lb\x1b[L+"); | |
824 | break; | |
825 | default: | |
826 | break; | |
827 | } | |
828 | return NOTIFY_DONE; | |
829 | } | |
830 | ||
831 | static struct notifier_block panel_notifier = { | |
832 | panel_notify_sys, | |
833 | NULL, | |
834 | 0 | |
835 | }; | |
836 | ||
837 | int charlcd_register(struct charlcd *lcd) | |
838 | { | |
839 | int ret; | |
840 | ||
841 | ret = charlcd_init(lcd); | |
842 | if (ret) | |
843 | return ret; | |
844 | ||
845 | ret = misc_register(&charlcd_dev); | |
846 | if (ret) | |
847 | return ret; | |
848 | ||
849 | the_charlcd = lcd; | |
850 | register_reboot_notifier(&panel_notifier); | |
851 | return 0; | |
852 | } | |
853 | EXPORT_SYMBOL_GPL(charlcd_register); | |
854 | ||
855 | int charlcd_unregister(struct charlcd *lcd) | |
856 | { | |
b658a211 | 857 | struct charlcd_priv *priv = charlcd_to_priv(lcd); |
39f8ea46 GU |
858 | |
859 | unregister_reboot_notifier(&panel_notifier); | |
860 | charlcd_puts(lcd, "\x0cLCD driver unloaded.\x1b[Lc\x1b[Lb\x1b[L-"); | |
861 | misc_deregister(&charlcd_dev); | |
862 | the_charlcd = NULL; | |
863 | if (lcd->ops->backlight) { | |
864 | cancel_delayed_work_sync(&priv->bl_work); | |
865 | priv->lcd.ops->backlight(&priv->lcd, 0); | |
866 | } | |
867 | ||
868 | return 0; | |
869 | } | |
870 | EXPORT_SYMBOL_GPL(charlcd_unregister); | |
871 | ||
872 | MODULE_LICENSE("GPL"); |