Samuel Thibault | f7511d5 | 2008-04-30 00:54:51 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Minimalistic braille device kernel support. |
| 3 | * |
| 4 | * By default, shows console messages on the braille device. |
| 5 | * Pressing Insert switches to VC browsing. |
| 6 | * |
| 7 | * Copyright (C) Samuel Thibault <samuel.thibault@ens-lyon.org> |
| 8 | * |
| 9 | * This program is free software ; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation ; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY ; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the program ; if not, write to the Free Software |
| 21 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 22 | */ |
| 23 | |
| 24 | #include <linux/autoconf.h> |
| 25 | #include <linux/kernel.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/moduleparam.h> |
| 28 | #include <linux/console.h> |
| 29 | #include <linux/notifier.h> |
| 30 | |
| 31 | #include <linux/selection.h> |
| 32 | #include <linux/vt_kern.h> |
| 33 | #include <linux/consolemap.h> |
| 34 | |
| 35 | #include <linux/keyboard.h> |
| 36 | #include <linux/kbd_kern.h> |
| 37 | #include <linux/input.h> |
| 38 | |
| 39 | MODULE_AUTHOR("samuel.thibault@ens-lyon.org"); |
| 40 | MODULE_DESCRIPTION("braille device"); |
| 41 | MODULE_LICENSE("GPL"); |
| 42 | |
| 43 | /* |
| 44 | * Braille device support part. |
| 45 | */ |
| 46 | |
| 47 | /* Emit various sounds */ |
| 48 | static int sound; |
| 49 | module_param(sound, bool, 0); |
| 50 | MODULE_PARM_DESC(sound, "emit sounds"); |
| 51 | |
| 52 | static void beep(unsigned int freq) |
| 53 | { |
| 54 | if (sound) |
| 55 | kd_mksound(freq, HZ/10); |
| 56 | } |
| 57 | |
| 58 | /* mini console */ |
| 59 | #define WIDTH 40 |
| 60 | #define BRAILLE_KEY KEY_INSERT |
| 61 | static u16 console_buf[WIDTH]; |
| 62 | static int console_cursor; |
| 63 | |
| 64 | /* mini view of VC */ |
| 65 | static int vc_x, vc_y, lastvc_x, lastvc_y; |
| 66 | |
| 67 | /* show console ? (or show VC) */ |
| 68 | static int console_show = 1; |
| 69 | /* pending newline ? */ |
| 70 | static int console_newline = 1; |
| 71 | static int lastVC = -1; |
| 72 | |
| 73 | static struct console *braille_co; |
| 74 | |
| 75 | /* Very VisioBraille-specific */ |
| 76 | static void braille_write(u16 *buf) |
| 77 | { |
| 78 | static u16 lastwrite[WIDTH]; |
| 79 | unsigned char data[1 + 1 + 2*WIDTH + 2 + 1], csum = 0, *c; |
| 80 | u16 out; |
| 81 | int i; |
| 82 | |
| 83 | if (!braille_co) |
| 84 | return; |
| 85 | |
| 86 | if (!memcmp(lastwrite, buf, WIDTH * sizeof(*buf))) |
| 87 | return; |
| 88 | memcpy(lastwrite, buf, WIDTH * sizeof(*buf)); |
| 89 | |
| 90 | #define SOH 1 |
| 91 | #define STX 2 |
| 92 | #define ETX 2 |
| 93 | #define EOT 4 |
| 94 | #define ENQ 5 |
| 95 | data[0] = STX; |
| 96 | data[1] = '>'; |
| 97 | csum ^= '>'; |
| 98 | c = &data[2]; |
| 99 | for (i = 0; i < WIDTH; i++) { |
| 100 | out = buf[i]; |
| 101 | if (out >= 0x100) |
| 102 | out = '?'; |
| 103 | else if (out == 0x00) |
| 104 | out = ' '; |
| 105 | csum ^= out; |
| 106 | if (out <= 0x05) { |
| 107 | *c++ = SOH; |
| 108 | out |= 0x40; |
| 109 | } |
| 110 | *c++ = out; |
| 111 | } |
| 112 | |
| 113 | if (csum <= 0x05) { |
| 114 | *c++ = SOH; |
| 115 | csum |= 0x40; |
| 116 | } |
| 117 | *c++ = csum; |
| 118 | *c++ = ETX; |
| 119 | |
| 120 | braille_co->write(braille_co, data, c - data); |
| 121 | } |
| 122 | |
| 123 | /* Follow the VC cursor*/ |
| 124 | static void vc_follow_cursor(struct vc_data *vc) |
| 125 | { |
| 126 | vc_x = vc->vc_x - (vc->vc_x % WIDTH); |
| 127 | vc_y = vc->vc_y; |
| 128 | lastvc_x = vc->vc_x; |
| 129 | lastvc_y = vc->vc_y; |
| 130 | } |
| 131 | |
| 132 | /* Maybe the VC cursor moved, if so follow it */ |
| 133 | static void vc_maybe_cursor_moved(struct vc_data *vc) |
| 134 | { |
| 135 | if (vc->vc_x != lastvc_x || vc->vc_y != lastvc_y) |
| 136 | vc_follow_cursor(vc); |
| 137 | } |
| 138 | |
| 139 | /* Show portion of VC at vc_x, vc_y */ |
| 140 | static void vc_refresh(struct vc_data *vc) |
| 141 | { |
| 142 | u16 buf[WIDTH]; |
| 143 | int i; |
| 144 | |
| 145 | for (i = 0; i < WIDTH; i++) { |
| 146 | u16 glyph = screen_glyph(vc, |
| 147 | 2 * (vc_x + i) + vc_y * vc->vc_size_row); |
| 148 | buf[i] = inverse_translate(vc, glyph, 1); |
| 149 | } |
| 150 | braille_write(buf); |
| 151 | } |
| 152 | |
| 153 | /* |
| 154 | * Link to keyboard |
| 155 | */ |
| 156 | |
| 157 | static int keyboard_notifier_call(struct notifier_block *blk, |
| 158 | unsigned long code, void *_param) |
| 159 | { |
| 160 | struct keyboard_notifier_param *param = _param; |
| 161 | struct vc_data *vc = param->vc; |
| 162 | int ret = NOTIFY_OK; |
| 163 | |
| 164 | if (!param->down) |
| 165 | return ret; |
| 166 | |
| 167 | switch (code) { |
| 168 | case KBD_KEYCODE: |
| 169 | if (console_show) { |
| 170 | if (param->value == BRAILLE_KEY) { |
| 171 | console_show = 0; |
| 172 | beep(880); |
| 173 | vc_maybe_cursor_moved(vc); |
| 174 | vc_refresh(vc); |
| 175 | ret = NOTIFY_STOP; |
| 176 | } |
| 177 | } else { |
| 178 | ret = NOTIFY_STOP; |
| 179 | switch (param->value) { |
| 180 | case KEY_INSERT: |
| 181 | beep(440); |
| 182 | console_show = 1; |
| 183 | lastVC = -1; |
| 184 | braille_write(console_buf); |
| 185 | break; |
| 186 | case KEY_LEFT: |
| 187 | if (vc_x > 0) { |
| 188 | vc_x -= WIDTH; |
| 189 | if (vc_x < 0) |
| 190 | vc_x = 0; |
| 191 | } else if (vc_y >= 1) { |
| 192 | beep(880); |
| 193 | vc_y--; |
| 194 | vc_x = vc->vc_cols-WIDTH; |
| 195 | } else |
| 196 | beep(220); |
| 197 | break; |
| 198 | case KEY_RIGHT: |
| 199 | if (vc_x + WIDTH < vc->vc_cols) { |
| 200 | vc_x += WIDTH; |
| 201 | } else if (vc_y + 1 < vc->vc_rows) { |
| 202 | beep(880); |
| 203 | vc_y++; |
| 204 | vc_x = 0; |
| 205 | } else |
| 206 | beep(220); |
| 207 | break; |
| 208 | case KEY_DOWN: |
| 209 | if (vc_y + 1 < vc->vc_rows) |
| 210 | vc_y++; |
| 211 | else |
| 212 | beep(220); |
| 213 | break; |
| 214 | case KEY_UP: |
| 215 | if (vc_y >= 1) |
| 216 | vc_y--; |
| 217 | else |
| 218 | beep(220); |
| 219 | break; |
| 220 | case KEY_HOME: |
| 221 | vc_follow_cursor(vc); |
| 222 | break; |
| 223 | case KEY_PAGEUP: |
| 224 | vc_x = 0; |
| 225 | vc_y = 0; |
| 226 | break; |
| 227 | case KEY_PAGEDOWN: |
| 228 | vc_x = 0; |
| 229 | vc_y = vc->vc_rows-1; |
| 230 | break; |
| 231 | default: |
| 232 | ret = NOTIFY_OK; |
| 233 | break; |
| 234 | } |
| 235 | if (ret == NOTIFY_STOP) |
| 236 | vc_refresh(vc); |
| 237 | } |
| 238 | break; |
| 239 | case KBD_POST_KEYSYM: |
| 240 | { |
| 241 | unsigned char type = KTYP(param->value) - 0xf0; |
| 242 | if (type == KT_SPEC) { |
| 243 | unsigned char val = KVAL(param->value); |
| 244 | int on_off = -1; |
| 245 | |
| 246 | switch (val) { |
| 247 | case KVAL(K_CAPS): |
| 248 | on_off = vc_kbd_led(kbd_table + fg_console, |
| 249 | VC_CAPSLOCK); |
| 250 | break; |
| 251 | case KVAL(K_NUM): |
| 252 | on_off = vc_kbd_led(kbd_table + fg_console, |
| 253 | VC_NUMLOCK); |
| 254 | break; |
| 255 | case KVAL(K_HOLD): |
| 256 | on_off = vc_kbd_led(kbd_table + fg_console, |
| 257 | VC_SCROLLOCK); |
| 258 | break; |
| 259 | } |
| 260 | if (on_off == 1) |
| 261 | beep(880); |
| 262 | else if (on_off == 0) |
| 263 | beep(440); |
| 264 | } |
| 265 | } |
| 266 | case KBD_UNBOUND_KEYCODE: |
| 267 | case KBD_UNICODE: |
| 268 | case KBD_KEYSYM: |
| 269 | /* Unused */ |
| 270 | break; |
| 271 | } |
| 272 | return ret; |
| 273 | } |
| 274 | |
| 275 | static struct notifier_block keyboard_notifier_block = { |
| 276 | .notifier_call = keyboard_notifier_call, |
| 277 | }; |
| 278 | |
| 279 | static int vt_notifier_call(struct notifier_block *blk, |
| 280 | unsigned long code, void *_param) |
| 281 | { |
| 282 | struct vt_notifier_param *param = _param; |
| 283 | struct vc_data *vc = param->vc; |
| 284 | switch (code) { |
| 285 | case VT_ALLOCATE: |
| 286 | break; |
| 287 | case VT_DEALLOCATE: |
| 288 | break; |
| 289 | case VT_WRITE: |
| 290 | { |
| 291 | unsigned char c = param->c; |
| 292 | if (vc->vc_num != fg_console) |
| 293 | break; |
| 294 | switch (c) { |
| 295 | case '\b': |
| 296 | case 127: |
| 297 | if (console_cursor > 0) { |
| 298 | console_cursor--; |
| 299 | console_buf[console_cursor] = ' '; |
| 300 | } |
| 301 | break; |
| 302 | case '\n': |
| 303 | case '\v': |
| 304 | case '\f': |
| 305 | case '\r': |
| 306 | console_newline = 1; |
| 307 | break; |
| 308 | case '\t': |
| 309 | c = ' '; |
| 310 | /* Fallthrough */ |
| 311 | default: |
| 312 | if (c < 32) |
| 313 | /* Ignore other control sequences */ |
| 314 | break; |
| 315 | if (console_newline) { |
| 316 | memset(console_buf, 0, sizeof(console_buf)); |
| 317 | console_cursor = 0; |
| 318 | console_newline = 0; |
| 319 | } |
| 320 | if (console_cursor == WIDTH) |
| 321 | memmove(console_buf, &console_buf[1], |
| 322 | (WIDTH-1) * sizeof(*console_buf)); |
| 323 | else |
| 324 | console_cursor++; |
| 325 | console_buf[console_cursor-1] = c; |
| 326 | break; |
| 327 | } |
| 328 | if (console_show) |
| 329 | braille_write(console_buf); |
| 330 | else { |
| 331 | vc_maybe_cursor_moved(vc); |
| 332 | vc_refresh(vc); |
| 333 | } |
| 334 | break; |
| 335 | } |
| 336 | case VT_UPDATE: |
| 337 | /* Maybe a VT switch, flush */ |
| 338 | if (console_show) { |
| 339 | if (vc->vc_num != lastVC) { |
| 340 | lastVC = vc->vc_num; |
| 341 | memset(console_buf, 0, sizeof(console_buf)); |
| 342 | console_cursor = 0; |
| 343 | braille_write(console_buf); |
| 344 | } |
| 345 | } else { |
| 346 | vc_maybe_cursor_moved(vc); |
| 347 | vc_refresh(vc); |
| 348 | } |
| 349 | break; |
| 350 | } |
| 351 | return NOTIFY_OK; |
| 352 | } |
| 353 | |
| 354 | static struct notifier_block vt_notifier_block = { |
| 355 | .notifier_call = vt_notifier_call, |
| 356 | }; |
| 357 | |
| 358 | /* |
| 359 | * Called from printk.c when console=brl is given |
| 360 | */ |
| 361 | |
| 362 | int braille_register_console(struct console *console, int index, |
| 363 | char *console_options, char *braille_options) |
| 364 | { |
| 365 | int ret; |
| 366 | if (!console_options) |
| 367 | /* Only support VisioBraille for now */ |
| 368 | console_options = "57600o8"; |
| 369 | if (braille_co) |
| 370 | return -ENODEV; |
| 371 | if (console->setup) { |
| 372 | ret = console->setup(console, console_options); |
| 373 | if (ret != 0) |
| 374 | return ret; |
| 375 | } |
| 376 | console->flags |= CON_ENABLED; |
| 377 | console->index = index; |
| 378 | braille_co = console; |
| 379 | return 0; |
| 380 | } |
| 381 | |
| 382 | int braille_unregister_console(struct console *console) |
| 383 | { |
| 384 | if (braille_co != console) |
| 385 | return -EINVAL; |
| 386 | braille_co = NULL; |
| 387 | return 0; |
| 388 | } |
| 389 | |
| 390 | static int __init braille_init(void) |
| 391 | { |
| 392 | register_keyboard_notifier(&keyboard_notifier_block); |
| 393 | register_vt_notifier(&vt_notifier_block); |
| 394 | return 0; |
| 395 | } |
| 396 | |
| 397 | console_initcall(braille_init); |