1 /* 2 * PS/2 driver library 3 * 4 * Copyright (c) 1999-2002 Vojtech Pavlik 5 * Copyright (c) 2004 Dmitry Torokhov 6 */ 7 8 /* 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License version 2 as published by 11 * the Free Software Foundation. 12 */ 13 14 #include <linux/delay.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/interrupt.h> 18 #include <linux/input.h> 19 #include <linux/serio.h> 20 #include <linux/i8042.h> 21 #include <linux/libps2.h> 22 23 #define DRIVER_DESC "PS/2 driver library" 24 25 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); 26 MODULE_DESCRIPTION("PS/2 driver library"); 27 MODULE_LICENSE("GPL"); 28 29 /* 30 * ps2_sendbyte() sends a byte to the device and waits for acknowledge. 31 * It doesn't handle retransmission, though it could - because if there 32 * is a need for retransmissions device has to be replaced anyway. 33 * 34 * ps2_sendbyte() can only be called from a process context. 35 */ 36 37 int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout) 38 { 39 serio_pause_rx(ps2dev->serio); 40 ps2dev->nak = 1; 41 ps2dev->flags |= PS2_FLAG_ACK; 42 serio_continue_rx(ps2dev->serio); 43 44 if (serio_write(ps2dev->serio, byte) == 0) 45 wait_event_timeout(ps2dev->wait, 46 !(ps2dev->flags & PS2_FLAG_ACK), 47 msecs_to_jiffies(timeout)); 48 49 serio_pause_rx(ps2dev->serio); 50 ps2dev->flags &= ~PS2_FLAG_ACK; 51 serio_continue_rx(ps2dev->serio); 52 53 return -ps2dev->nak; 54 } 55 EXPORT_SYMBOL(ps2_sendbyte); 56 57 void ps2_begin_command(struct ps2dev *ps2dev) 58 { 59 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; 60 61 mutex_lock(m); 62 } 63 EXPORT_SYMBOL(ps2_begin_command); 64 65 void ps2_end_command(struct ps2dev *ps2dev) 66 { 67 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; 68 69 mutex_unlock(m); 70 } 71 EXPORT_SYMBOL(ps2_end_command); 72 73 /* 74 * ps2_drain() waits for device to transmit requested number of bytes 75 * and discards them. 76 */ 77 78 void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout) 79 { 80 if (maxbytes > sizeof(ps2dev->cmdbuf)) { 81 WARN_ON(1); 82 maxbytes = sizeof(ps2dev->cmdbuf); 83 } 84 85 ps2_begin_command(ps2dev); 86 87 serio_pause_rx(ps2dev->serio); 88 ps2dev->flags = PS2_FLAG_CMD; 89 ps2dev->cmdcnt = maxbytes; 90 serio_continue_rx(ps2dev->serio); 91 92 wait_event_timeout(ps2dev->wait, 93 !(ps2dev->flags & PS2_FLAG_CMD), 94 msecs_to_jiffies(timeout)); 95 96 ps2_end_command(ps2dev); 97 } 98 EXPORT_SYMBOL(ps2_drain); 99 100 /* 101 * ps2_is_keyboard_id() checks received ID byte against the list of 102 * known keyboard IDs. 103 */ 104 105 int ps2_is_keyboard_id(char id_byte) 106 { 107 static const char keyboard_ids[] = { 108 0xab, /* Regular keyboards */ 109 0xac, /* NCD Sun keyboard */ 110 0x2b, /* Trust keyboard, translated */ 111 0x5d, /* Trust keyboard */ 112 0x60, /* NMB SGI keyboard, translated */ 113 0x47, /* NMB SGI keyboard */ 114 }; 115 116 return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL; 117 } 118 EXPORT_SYMBOL(ps2_is_keyboard_id); 119 120 /* 121 * ps2_adjust_timeout() is called after receiving 1st byte of command 122 * response and tries to reduce remaining timeout to speed up command 123 * completion. 124 */ 125 126 static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout) 127 { 128 switch (command) { 129 case PS2_CMD_RESET_BAT: 130 /* 131 * Device has sent the first response byte after 132 * reset command, reset is thus done, so we can 133 * shorten the timeout. 134 * The next byte will come soon (keyboard) or not 135 * at all (mouse). 136 */ 137 if (timeout > msecs_to_jiffies(100)) 138 timeout = msecs_to_jiffies(100); 139 break; 140 141 case PS2_CMD_GETID: 142 /* 143 * Microsoft Natural Elite keyboard responds to 144 * the GET ID command as it were a mouse, with 145 * a single byte. Fail the command so atkbd will 146 * use alternative probe to detect it. 147 */ 148 if (ps2dev->cmdbuf[1] == 0xaa) { 149 serio_pause_rx(ps2dev->serio); 150 ps2dev->flags = 0; 151 serio_continue_rx(ps2dev->serio); 152 timeout = 0; 153 } 154 155 /* 156 * If device behind the port is not a keyboard there 157 * won't be 2nd byte of ID response. 158 */ 159 if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) { 160 serio_pause_rx(ps2dev->serio); 161 ps2dev->flags = ps2dev->cmdcnt = 0; 162 serio_continue_rx(ps2dev->serio); 163 timeout = 0; 164 } 165 break; 166 167 default: 168 break; 169 } 170 171 return timeout; 172 } 173 174 /* 175 * ps2_command() sends a command and its parameters to the mouse, 176 * then waits for the response and puts it in the param array. 177 * 178 * ps2_command() can only be called from a process context 179 */ 180 181 int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command) 182 { 183 int timeout; 184 int send = (command >> 12) & 0xf; 185 int receive = (command >> 8) & 0xf; 186 int rc = -1; 187 int i; 188 189 if (receive > sizeof(ps2dev->cmdbuf)) { 190 WARN_ON(1); 191 return -1; 192 } 193 194 if (send && !param) { 195 WARN_ON(1); 196 return -1; 197 } 198 199 serio_pause_rx(ps2dev->serio); 200 ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; 201 ps2dev->cmdcnt = receive; 202 if (receive && param) 203 for (i = 0; i < receive; i++) 204 ps2dev->cmdbuf[(receive - 1) - i] = param[i]; 205 serio_continue_rx(ps2dev->serio); 206 207 /* 208 * Some devices (Synaptics) peform the reset before 209 * ACKing the reset command, and so it can take a long 210 * time before the ACK arrives. 211 */ 212 if (ps2_sendbyte(ps2dev, command & 0xff, 213 command == PS2_CMD_RESET_BAT ? 1000 : 200)) { 214 serio_pause_rx(ps2dev->serio); 215 goto out_reset_flags; 216 } 217 218 for (i = 0; i < send; i++) { 219 if (ps2_sendbyte(ps2dev, param[i], 200)) { 220 serio_pause_rx(ps2dev->serio); 221 goto out_reset_flags; 222 } 223 } 224 225 /* 226 * The reset command takes a long time to execute. 227 */ 228 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500); 229 230 timeout = wait_event_timeout(ps2dev->wait, 231 !(ps2dev->flags & PS2_FLAG_CMD1), timeout); 232 233 if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) { 234 235 timeout = ps2_adjust_timeout(ps2dev, command, timeout); 236 wait_event_timeout(ps2dev->wait, 237 !(ps2dev->flags & PS2_FLAG_CMD), timeout); 238 } 239 240 serio_pause_rx(ps2dev->serio); 241 242 if (param) 243 for (i = 0; i < receive; i++) 244 param[i] = ps2dev->cmdbuf[(receive - 1) - i]; 245 246 if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) 247 goto out_reset_flags; 248 249 rc = 0; 250 251 out_reset_flags: 252 ps2dev->flags = 0; 253 serio_continue_rx(ps2dev->serio); 254 255 return rc; 256 } 257 EXPORT_SYMBOL(__ps2_command); 258 259 int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command) 260 { 261 int rc; 262 263 ps2_begin_command(ps2dev); 264 rc = __ps2_command(ps2dev, param, command); 265 ps2_end_command(ps2dev); 266 267 return rc; 268 } 269 EXPORT_SYMBOL(ps2_command); 270 271 /* 272 * ps2_init() initializes ps2dev structure 273 */ 274 275 void ps2_init(struct ps2dev *ps2dev, struct serio *serio) 276 { 277 mutex_init(&ps2dev->cmd_mutex); 278 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth); 279 init_waitqueue_head(&ps2dev->wait); 280 ps2dev->serio = serio; 281 } 282 EXPORT_SYMBOL(ps2_init); 283 284 /* 285 * ps2_handle_ack() is supposed to be used in interrupt handler 286 * to properly process ACK/NAK of a command from a PS/2 device. 287 */ 288 289 int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data) 290 { 291 switch (data) { 292 case PS2_RET_ACK: 293 ps2dev->nak = 0; 294 break; 295 296 case PS2_RET_NAK: 297 ps2dev->flags |= PS2_FLAG_NAK; 298 ps2dev->nak = PS2_RET_NAK; 299 break; 300 301 case PS2_RET_ERR: 302 if (ps2dev->flags & PS2_FLAG_NAK) { 303 ps2dev->flags &= ~PS2_FLAG_NAK; 304 ps2dev->nak = PS2_RET_ERR; 305 break; 306 } 307 308 /* 309 * Workaround for mice which don't ACK the Get ID command. 310 * These are valid mouse IDs that we recognize. 311 */ 312 case 0x00: 313 case 0x03: 314 case 0x04: 315 if (ps2dev->flags & PS2_FLAG_WAITID) { 316 ps2dev->nak = 0; 317 break; 318 } 319 /* Fall through */ 320 default: 321 return 0; 322 } 323 324 325 if (!ps2dev->nak) { 326 ps2dev->flags &= ~PS2_FLAG_NAK; 327 if (ps2dev->cmdcnt) 328 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1; 329 } 330 331 ps2dev->flags &= ~PS2_FLAG_ACK; 332 wake_up(&ps2dev->wait); 333 334 if (data != PS2_RET_ACK) 335 ps2_handle_response(ps2dev, data); 336 337 return 1; 338 } 339 EXPORT_SYMBOL(ps2_handle_ack); 340 341 /* 342 * ps2_handle_response() is supposed to be used in interrupt handler 343 * to properly store device's response to a command and notify process 344 * waiting for completion of the command. 345 */ 346 347 int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data) 348 { 349 if (ps2dev->cmdcnt) 350 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data; 351 352 if (ps2dev->flags & PS2_FLAG_CMD1) { 353 ps2dev->flags &= ~PS2_FLAG_CMD1; 354 if (ps2dev->cmdcnt) 355 wake_up(&ps2dev->wait); 356 } 357 358 if (!ps2dev->cmdcnt) { 359 ps2dev->flags &= ~PS2_FLAG_CMD; 360 wake_up(&ps2dev->wait); 361 } 362 363 return 1; 364 } 365 EXPORT_SYMBOL(ps2_handle_response); 366 367 void ps2_cmd_aborted(struct ps2dev *ps2dev) 368 { 369 if (ps2dev->flags & PS2_FLAG_ACK) 370 ps2dev->nak = 1; 371 372 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD)) 373 wake_up(&ps2dev->wait); 374 375 /* reset all flags except last nack */ 376 ps2dev->flags &= PS2_FLAG_NAK; 377 } 378 EXPORT_SYMBOL(ps2_cmd_aborted); 379