Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/moduleparam.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/input.h> |
| 20 | #include <linux/serio.h> |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/libps2.h> |
| 23 | |
| 24 | #define DRIVER_DESC "PS/2 driver library" |
| 25 | |
| 26 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); |
| 27 | MODULE_DESCRIPTION("PS/2 driver library"); |
| 28 | MODULE_LICENSE("GPL"); |
| 29 | |
| 30 | EXPORT_SYMBOL(ps2_init); |
| 31 | EXPORT_SYMBOL(ps2_sendbyte); |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 32 | EXPORT_SYMBOL(ps2_drain); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | EXPORT_SYMBOL(ps2_command); |
| 34 | EXPORT_SYMBOL(ps2_schedule_command); |
| 35 | EXPORT_SYMBOL(ps2_handle_ack); |
| 36 | EXPORT_SYMBOL(ps2_handle_response); |
| 37 | EXPORT_SYMBOL(ps2_cmd_aborted); |
| 38 | |
| 39 | /* Work structure to schedule execution of a command */ |
| 40 | struct ps2work { |
| 41 | struct work_struct work; |
| 42 | struct ps2dev *ps2dev; |
| 43 | int command; |
| 44 | unsigned char param[0]; |
| 45 | }; |
| 46 | |
| 47 | |
| 48 | /* |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 49 | * ps2_sendbyte() sends a byte to the device and waits for acknowledge. |
| 50 | * It doesn't handle retransmission, though it could - because if there |
| 51 | * is a need for retransmissions device has to be replaced anyway. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | * |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 53 | * ps2_sendbyte() can only be called from a process context. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | */ |
| 55 | |
| 56 | int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout) |
| 57 | { |
| 58 | serio_pause_rx(ps2dev->serio); |
| 59 | ps2dev->nak = 1; |
| 60 | ps2dev->flags |= PS2_FLAG_ACK; |
| 61 | serio_continue_rx(ps2dev->serio); |
| 62 | |
| 63 | if (serio_write(ps2dev->serio, byte) == 0) |
| 64 | wait_event_timeout(ps2dev->wait, |
| 65 | !(ps2dev->flags & PS2_FLAG_ACK), |
| 66 | msecs_to_jiffies(timeout)); |
| 67 | |
| 68 | serio_pause_rx(ps2dev->serio); |
| 69 | ps2dev->flags &= ~PS2_FLAG_ACK; |
| 70 | serio_continue_rx(ps2dev->serio); |
| 71 | |
| 72 | return -ps2dev->nak; |
| 73 | } |
| 74 | |
| 75 | /* |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 76 | * ps2_drain() waits for device to transmit requested number of bytes |
| 77 | * and discards them. |
| 78 | */ |
| 79 | |
| 80 | void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout) |
| 81 | { |
| 82 | if (maxbytes > sizeof(ps2dev->cmdbuf)) { |
| 83 | WARN_ON(1); |
| 84 | maxbytes = sizeof(ps2dev->cmdbuf); |
| 85 | } |
| 86 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 87 | mutex_lock(&ps2dev->cmd_mutex); |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 88 | |
| 89 | serio_pause_rx(ps2dev->serio); |
| 90 | ps2dev->flags = PS2_FLAG_CMD; |
| 91 | ps2dev->cmdcnt = maxbytes; |
| 92 | serio_continue_rx(ps2dev->serio); |
| 93 | |
| 94 | wait_event_timeout(ps2dev->wait, |
| 95 | !(ps2dev->flags & PS2_FLAG_CMD), |
| 96 | msecs_to_jiffies(timeout)); |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 97 | mutex_unlock(&ps2dev->cmd_mutex); |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 98 | } |
| 99 | |
| 100 | /* |
Dmitry Torokhov | 905ab9d | 2005-06-01 02:39:53 -0500 | [diff] [blame] | 101 | * ps2_is_keyboard_id() checks received ID byte against the list of |
| 102 | * known keyboard IDs. |
| 103 | */ |
| 104 | |
| 105 | static inline int ps2_is_keyboard_id(char id_byte) |
| 106 | { |
| 107 | static 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 | |
| 119 | /* |
| 120 | * ps2_adjust_timeout() is called after receiving 1st byte of command |
| 121 | * response and tries to reduce remaining timeout to speed up command |
| 122 | * completion. |
| 123 | */ |
| 124 | |
| 125 | static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout) |
| 126 | { |
| 127 | switch (command) { |
| 128 | case PS2_CMD_RESET_BAT: |
| 129 | /* |
| 130 | * Device has sent the first response byte after |
| 131 | * reset command, reset is thus done, so we can |
| 132 | * shorten the timeout. |
| 133 | * The next byte will come soon (keyboard) or not |
| 134 | * at all (mouse). |
| 135 | */ |
| 136 | if (timeout > msecs_to_jiffies(100)) |
| 137 | timeout = msecs_to_jiffies(100); |
| 138 | break; |
| 139 | |
| 140 | case PS2_CMD_GETID: |
| 141 | /* |
| 142 | * If device behind the port is not a keyboard there |
| 143 | * won't be 2nd byte of ID response. |
| 144 | */ |
| 145 | if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) { |
| 146 | serio_pause_rx(ps2dev->serio); |
| 147 | ps2dev->flags = ps2dev->cmdcnt = 0; |
| 148 | serio_continue_rx(ps2dev->serio); |
| 149 | timeout = 0; |
| 150 | } |
| 151 | break; |
| 152 | |
| 153 | default: |
| 154 | break; |
| 155 | } |
| 156 | |
| 157 | return timeout; |
| 158 | } |
| 159 | |
| 160 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | * ps2_command() sends a command and its parameters to the mouse, |
| 162 | * then waits for the response and puts it in the param array. |
| 163 | * |
| 164 | * ps2_command() can only be called from a process context |
| 165 | */ |
| 166 | |
| 167 | int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command) |
| 168 | { |
| 169 | int timeout; |
| 170 | int send = (command >> 12) & 0xf; |
| 171 | int receive = (command >> 8) & 0xf; |
| 172 | int rc = -1; |
| 173 | int i; |
| 174 | |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 175 | if (receive > sizeof(ps2dev->cmdbuf)) { |
| 176 | WARN_ON(1); |
| 177 | return -1; |
| 178 | } |
| 179 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 180 | mutex_lock(&ps2dev->cmd_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
| 182 | serio_pause_rx(ps2dev->serio); |
| 183 | ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; |
| 184 | ps2dev->cmdcnt = receive; |
| 185 | if (receive && param) |
| 186 | for (i = 0; i < receive; i++) |
| 187 | ps2dev->cmdbuf[(receive - 1) - i] = param[i]; |
| 188 | serio_continue_rx(ps2dev->serio); |
| 189 | |
| 190 | /* |
| 191 | * Some devices (Synaptics) peform the reset before |
| 192 | * ACKing the reset command, and so it can take a long |
| 193 | * time before the ACK arrrives. |
| 194 | */ |
Dmitry Torokhov | c611763 | 2005-06-01 02:39:51 -0500 | [diff] [blame] | 195 | if (ps2_sendbyte(ps2dev, command & 0xff, |
| 196 | command == PS2_CMD_RESET_BAT ? 1000 : 200)) |
| 197 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
| 199 | for (i = 0; i < send; i++) |
| 200 | if (ps2_sendbyte(ps2dev, param[i], 200)) |
| 201 | goto out; |
| 202 | |
| 203 | /* |
| 204 | * The reset command takes a long time to execute. |
| 205 | */ |
| 206 | timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500); |
| 207 | |
| 208 | timeout = wait_event_timeout(ps2dev->wait, |
| 209 | !(ps2dev->flags & PS2_FLAG_CMD1), timeout); |
| 210 | |
| 211 | if (ps2dev->cmdcnt && timeout > 0) { |
| 212 | |
Dmitry Torokhov | 905ab9d | 2005-06-01 02:39:53 -0500 | [diff] [blame] | 213 | timeout = ps2_adjust_timeout(ps2dev, command, timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | wait_event_timeout(ps2dev->wait, |
| 215 | !(ps2dev->flags & PS2_FLAG_CMD), timeout); |
| 216 | } |
| 217 | |
| 218 | if (param) |
| 219 | for (i = 0; i < receive; i++) |
| 220 | param[i] = ps2dev->cmdbuf[(receive - 1) - i]; |
| 221 | |
| 222 | if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) |
| 223 | goto out; |
| 224 | |
| 225 | rc = 0; |
| 226 | |
Dmitry Torokhov | 905ab9d | 2005-06-01 02:39:53 -0500 | [diff] [blame] | 227 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | serio_pause_rx(ps2dev->serio); |
| 229 | ps2dev->flags = 0; |
| 230 | serio_continue_rx(ps2dev->serio); |
| 231 | |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 232 | mutex_unlock(&ps2dev->cmd_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | return rc; |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * ps2_execute_scheduled_command() sends a command, previously scheduled by |
| 238 | * ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.) |
| 239 | */ |
| 240 | |
| 241 | static void ps2_execute_scheduled_command(void *data) |
| 242 | { |
| 243 | struct ps2work *ps2work = data; |
| 244 | |
| 245 | ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command); |
| 246 | kfree(ps2work); |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * ps2_schedule_command() allows to schedule delayed execution of a PS/2 |
| 251 | * command and can be used to issue a command from an interrupt or softirq |
| 252 | * context. |
| 253 | */ |
| 254 | |
| 255 | int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command) |
| 256 | { |
| 257 | struct ps2work *ps2work; |
| 258 | int send = (command >> 12) & 0xf; |
| 259 | int receive = (command >> 8) & 0xf; |
| 260 | |
| 261 | if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC))) |
| 262 | return -1; |
| 263 | |
| 264 | memset(ps2work, 0, sizeof(struct ps2work)); |
| 265 | ps2work->ps2dev = ps2dev; |
| 266 | ps2work->command = command; |
| 267 | memcpy(ps2work->param, param, send); |
| 268 | INIT_WORK(&ps2work->work, ps2_execute_scheduled_command, ps2work); |
| 269 | |
| 270 | if (!schedule_work(&ps2work->work)) { |
| 271 | kfree(ps2work); |
| 272 | return -1; |
| 273 | } |
| 274 | |
| 275 | return 0; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * ps2_init() initializes ps2dev structure |
| 280 | */ |
| 281 | |
| 282 | void ps2_init(struct ps2dev *ps2dev, struct serio *serio) |
| 283 | { |
Arjan van de Ven | c4e32e9 | 2006-02-19 00:21:55 -0500 | [diff] [blame] | 284 | mutex_init(&ps2dev->cmd_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | init_waitqueue_head(&ps2dev->wait); |
| 286 | ps2dev->serio = serio; |
| 287 | } |
| 288 | |
| 289 | /* |
| 290 | * ps2_handle_ack() is supposed to be used in interrupt handler |
| 291 | * to properly process ACK/NAK of a command from a PS/2 device. |
| 292 | */ |
| 293 | |
| 294 | int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data) |
| 295 | { |
| 296 | switch (data) { |
| 297 | case PS2_RET_ACK: |
| 298 | ps2dev->nak = 0; |
| 299 | break; |
| 300 | |
| 301 | case PS2_RET_NAK: |
| 302 | ps2dev->nak = 1; |
| 303 | break; |
| 304 | |
| 305 | /* |
| 306 | * Workaround for mice which don't ACK the Get ID command. |
| 307 | * These are valid mouse IDs that we recognize. |
| 308 | */ |
| 309 | case 0x00: |
| 310 | case 0x03: |
| 311 | case 0x04: |
| 312 | if (ps2dev->flags & PS2_FLAG_WAITID) { |
| 313 | ps2dev->nak = 0; |
| 314 | break; |
| 315 | } |
| 316 | /* Fall through */ |
| 317 | default: |
| 318 | return 0; |
| 319 | } |
| 320 | |
| 321 | |
| 322 | if (!ps2dev->nak && ps2dev->cmdcnt) |
| 323 | ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1; |
| 324 | |
| 325 | ps2dev->flags &= ~PS2_FLAG_ACK; |
| 326 | wake_up(&ps2dev->wait); |
| 327 | |
| 328 | if (data != PS2_RET_ACK) |
| 329 | ps2_handle_response(ps2dev, data); |
| 330 | |
| 331 | return 1; |
| 332 | } |
| 333 | |
| 334 | /* |
| 335 | * ps2_handle_response() is supposed to be used in interrupt handler |
| 336 | * to properly store device's response to a command and notify process |
| 337 | * waiting for completion of the command. |
| 338 | */ |
| 339 | |
| 340 | int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data) |
| 341 | { |
| 342 | if (ps2dev->cmdcnt) |
| 343 | ps2dev->cmdbuf[--ps2dev->cmdcnt] = data; |
| 344 | |
| 345 | if (ps2dev->flags & PS2_FLAG_CMD1) { |
| 346 | ps2dev->flags &= ~PS2_FLAG_CMD1; |
| 347 | if (ps2dev->cmdcnt) |
| 348 | wake_up(&ps2dev->wait); |
| 349 | } |
| 350 | |
| 351 | if (!ps2dev->cmdcnt) { |
| 352 | ps2dev->flags &= ~PS2_FLAG_CMD; |
| 353 | wake_up(&ps2dev->wait); |
| 354 | } |
| 355 | |
| 356 | return 1; |
| 357 | } |
| 358 | |
| 359 | void ps2_cmd_aborted(struct ps2dev *ps2dev) |
| 360 | { |
| 361 | if (ps2dev->flags & PS2_FLAG_ACK) |
| 362 | ps2dev->nak = 1; |
| 363 | |
| 364 | if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD)) |
| 365 | wake_up(&ps2dev->wait); |
| 366 | |
| 367 | ps2dev->flags = 0; |
| 368 | } |
| 369 | |