]>
Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * PS/2 driver library | |
4 | * | |
5 | * Copyright (c) 1999-2002 Vojtech Pavlik | |
6 | * Copyright (c) 2004 Dmitry Torokhov | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | |
10 | #include <linux/delay.h> | |
11 | #include <linux/module.h> | |
d43c36dc | 12 | #include <linux/sched.h> |
1da177e4 LT |
13 | #include <linux/interrupt.h> |
14 | #include <linux/input.h> | |
15 | #include <linux/serio.h> | |
181d683d | 16 | #include <linux/i8042.h> |
1da177e4 LT |
17 | #include <linux/libps2.h> |
18 | ||
19 | #define DRIVER_DESC "PS/2 driver library" | |
20 | ||
21 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); | |
22 | MODULE_DESCRIPTION("PS/2 driver library"); | |
23 | MODULE_LICENSE("GPL"); | |
24 | ||
b99e1f2a DT |
25 | static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, |
26 | unsigned int timeout, unsigned int max_attempts) | |
27 | __releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock) | |
1da177e4 | 28 | { |
b99e1f2a | 29 | int attempt = 0; |
147b903d DT |
30 | int error; |
31 | ||
b99e1f2a | 32 | lockdep_assert_held(&ps2dev->serio->lock); |
1da177e4 | 33 | |
b99e1f2a DT |
34 | do { |
35 | ps2dev->nak = 1; | |
36 | ps2dev->flags |= PS2_FLAG_ACK; | |
37 | ||
38 | serio_continue_rx(ps2dev->serio); | |
39 | ||
40 | error = serio_write(ps2dev->serio, byte); | |
41 | if (error) | |
42 | dev_dbg(&ps2dev->serio->dev, | |
43 | "failed to write %#02x: %d\n", byte, error); | |
44 | else | |
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 | } while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts); | |
1da177e4 | 51 | |
1da177e4 | 52 | ps2dev->flags &= ~PS2_FLAG_ACK; |
1da177e4 | 53 | |
b99e1f2a DT |
54 | if (!error) { |
55 | switch (ps2dev->nak) { | |
56 | case 0: | |
57 | break; | |
58 | case PS2_RET_NAK: | |
59 | error = -EAGAIN; | |
60 | break; | |
61 | case PS2_RET_ERR: | |
62 | error = -EPROTO; | |
63 | break; | |
64 | default: | |
65 | error = -EIO; | |
66 | break; | |
67 | } | |
68 | } | |
69 | ||
70 | if (error || attempt > 1) | |
71 | dev_dbg(&ps2dev->serio->dev, | |
72 | "%02x - %d (%x), attempt %d\n", | |
73 | byte, error, ps2dev->nak, attempt); | |
74 | ||
75 | return error; | |
1da177e4 | 76 | } |
147b903d DT |
77 | |
78 | /* | |
79 | * ps2_sendbyte() sends a byte to the device and waits for acknowledge. | |
b99e1f2a DT |
80 | * It doesn't handle retransmission, the caller is expected to handle |
81 | * it when needed. | |
147b903d DT |
82 | * |
83 | * ps2_sendbyte() can only be called from a process context. | |
84 | */ | |
85 | ||
86 | int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout) | |
87 | { | |
88 | int retval; | |
89 | ||
b99e1f2a DT |
90 | serio_pause_rx(ps2dev->serio); |
91 | ||
92 | retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1); | |
147b903d DT |
93 | dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak); |
94 | ||
b99e1f2a DT |
95 | serio_continue_rx(ps2dev->serio); |
96 | ||
147b903d DT |
97 | return retval; |
98 | } | |
5206c0d5 | 99 | EXPORT_SYMBOL(ps2_sendbyte); |
1da177e4 | 100 | |
181d683d DT |
101 | void ps2_begin_command(struct ps2dev *ps2dev) |
102 | { | |
40974618 | 103 | struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; |
181d683d | 104 | |
40974618 | 105 | mutex_lock(m); |
181d683d DT |
106 | } |
107 | EXPORT_SYMBOL(ps2_begin_command); | |
108 | ||
109 | void ps2_end_command(struct ps2dev *ps2dev) | |
110 | { | |
40974618 | 111 | struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex; |
181d683d | 112 | |
40974618 | 113 | mutex_unlock(m); |
181d683d DT |
114 | } |
115 | EXPORT_SYMBOL(ps2_end_command); | |
116 | ||
c611763d DT |
117 | /* |
118 | * ps2_drain() waits for device to transmit requested number of bytes | |
119 | * and discards them. | |
120 | */ | |
121 | ||
b28bad65 | 122 | void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout) |
c611763d DT |
123 | { |
124 | if (maxbytes > sizeof(ps2dev->cmdbuf)) { | |
125 | WARN_ON(1); | |
126 | maxbytes = sizeof(ps2dev->cmdbuf); | |
127 | } | |
128 | ||
181d683d | 129 | ps2_begin_command(ps2dev); |
c611763d DT |
130 | |
131 | serio_pause_rx(ps2dev->serio); | |
132 | ps2dev->flags = PS2_FLAG_CMD; | |
133 | ps2dev->cmdcnt = maxbytes; | |
134 | serio_continue_rx(ps2dev->serio); | |
135 | ||
136 | wait_event_timeout(ps2dev->wait, | |
137 | !(ps2dev->flags & PS2_FLAG_CMD), | |
138 | msecs_to_jiffies(timeout)); | |
181d683d DT |
139 | |
140 | ps2_end_command(ps2dev); | |
c611763d | 141 | } |
5206c0d5 | 142 | EXPORT_SYMBOL(ps2_drain); |
c611763d | 143 | |
905ab9d1 DT |
144 | /* |
145 | * ps2_is_keyboard_id() checks received ID byte against the list of | |
146 | * known keyboard IDs. | |
147 | */ | |
148 | ||
b28bad65 | 149 | bool ps2_is_keyboard_id(u8 id_byte) |
905ab9d1 | 150 | { |
b28bad65 | 151 | static const u8 keyboard_ids[] = { |
905ab9d1 DT |
152 | 0xab, /* Regular keyboards */ |
153 | 0xac, /* NCD Sun keyboard */ | |
154 | 0x2b, /* Trust keyboard, translated */ | |
155 | 0x5d, /* Trust keyboard */ | |
156 | 0x60, /* NMB SGI keyboard, translated */ | |
157 | 0x47, /* NMB SGI keyboard */ | |
158 | }; | |
159 | ||
160 | return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL; | |
161 | } | |
5206c0d5 | 162 | EXPORT_SYMBOL(ps2_is_keyboard_id); |
905ab9d1 DT |
163 | |
164 | /* | |
165 | * ps2_adjust_timeout() is called after receiving 1st byte of command | |
166 | * response and tries to reduce remaining timeout to speed up command | |
167 | * completion. | |
168 | */ | |
169 | ||
b28bad65 DT |
170 | static int ps2_adjust_timeout(struct ps2dev *ps2dev, |
171 | unsigned int command, unsigned int timeout) | |
905ab9d1 DT |
172 | { |
173 | switch (command) { | |
d5e0d918 DT |
174 | case PS2_CMD_RESET_BAT: |
175 | /* | |
176 | * Device has sent the first response byte after | |
177 | * reset command, reset is thus done, so we can | |
178 | * shorten the timeout. | |
179 | * The next byte will come soon (keyboard) or not | |
180 | * at all (mouse). | |
181 | */ | |
182 | if (timeout > msecs_to_jiffies(100)) | |
183 | timeout = msecs_to_jiffies(100); | |
184 | break; | |
905ab9d1 | 185 | |
d5e0d918 DT |
186 | case PS2_CMD_GETID: |
187 | /* | |
188 | * Microsoft Natural Elite keyboard responds to | |
189 | * the GET ID command as it were a mouse, with | |
190 | * a single byte. Fail the command so atkbd will | |
191 | * use alternative probe to detect it. | |
192 | */ | |
193 | if (ps2dev->cmdbuf[1] == 0xaa) { | |
194 | serio_pause_rx(ps2dev->serio); | |
195 | ps2dev->flags = 0; | |
196 | serio_continue_rx(ps2dev->serio); | |
197 | timeout = 0; | |
198 | } | |
905ab9d1 | 199 | |
d5e0d918 DT |
200 | /* |
201 | * If device behind the port is not a keyboard there | |
202 | * won't be 2nd byte of ID response. | |
203 | */ | |
204 | if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) { | |
205 | serio_pause_rx(ps2dev->serio); | |
206 | ps2dev->flags = ps2dev->cmdcnt = 0; | |
207 | serio_continue_rx(ps2dev->serio); | |
208 | timeout = 0; | |
209 | } | |
210 | break; | |
211 | ||
212 | default: | |
213 | break; | |
905ab9d1 DT |
214 | } |
215 | ||
216 | return timeout; | |
217 | } | |
218 | ||
1da177e4 LT |
219 | /* |
220 | * ps2_command() sends a command and its parameters to the mouse, | |
221 | * then waits for the response and puts it in the param array. | |
222 | * | |
223 | * ps2_command() can only be called from a process context | |
224 | */ | |
225 | ||
b28bad65 | 226 | int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) |
1da177e4 | 227 | { |
b28bad65 DT |
228 | unsigned int timeout; |
229 | unsigned int send = (command >> 12) & 0xf; | |
230 | unsigned int receive = (command >> 8) & 0xf; | |
b99e1f2a | 231 | int rc; |
1da177e4 | 232 | int i; |
147b903d | 233 | u8 send_param[16]; |
1da177e4 | 234 | |
c611763d DT |
235 | if (receive > sizeof(ps2dev->cmdbuf)) { |
236 | WARN_ON(1); | |
b99e1f2a | 237 | return -EINVAL; |
c611763d DT |
238 | } |
239 | ||
95349fe8 DT |
240 | if (send && !param) { |
241 | WARN_ON(1); | |
b99e1f2a | 242 | return -EINVAL; |
95349fe8 DT |
243 | } |
244 | ||
147b903d DT |
245 | memcpy(send_param, param, send); |
246 | ||
1da177e4 | 247 | serio_pause_rx(ps2dev->serio); |
b99e1f2a | 248 | |
1da177e4 LT |
249 | ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; |
250 | ps2dev->cmdcnt = receive; | |
251 | if (receive && param) | |
252 | for (i = 0; i < receive; i++) | |
253 | ps2dev->cmdbuf[(receive - 1) - i] = param[i]; | |
1da177e4 | 254 | |
29acc42e DT |
255 | /* Signal that we are sending the command byte */ |
256 | ps2dev->flags |= PS2_FLAG_ACK_CMD; | |
257 | ||
1da177e4 LT |
258 | /* |
259 | * Some devices (Synaptics) peform the reset before | |
260 | * ACKing the reset command, and so it can take a long | |
83ae417b | 261 | * time before the ACK arrives. |
1da177e4 | 262 | */ |
29acc42e DT |
263 | timeout = command == PS2_CMD_RESET_BAT ? 1000 : 200; |
264 | ||
265 | rc = ps2_do_sendbyte(ps2dev, command & 0xff, timeout, 2); | |
b99e1f2a | 266 | if (rc) |
218c1f76 | 267 | goto out_reset_flags; |
1da177e4 | 268 | |
29acc42e DT |
269 | /* Now we are sending command parameters, if any */ |
270 | ps2dev->flags &= ~PS2_FLAG_ACK_CMD; | |
271 | ||
218c1f76 | 272 | for (i = 0; i < send; i++) { |
b99e1f2a DT |
273 | rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2); |
274 | if (rc) | |
218c1f76 | 275 | goto out_reset_flags; |
218c1f76 | 276 | } |
1da177e4 | 277 | |
b99e1f2a DT |
278 | serio_continue_rx(ps2dev->serio); |
279 | ||
1da177e4 LT |
280 | /* |
281 | * The reset command takes a long time to execute. | |
282 | */ | |
283 | timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500); | |
284 | ||
285 | timeout = wait_event_timeout(ps2dev->wait, | |
286 | !(ps2dev->flags & PS2_FLAG_CMD1), timeout); | |
287 | ||
a3ce6ea4 | 288 | if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) { |
1da177e4 | 289 | |
905ab9d1 | 290 | timeout = ps2_adjust_timeout(ps2dev, command, timeout); |
1da177e4 LT |
291 | wait_event_timeout(ps2dev->wait, |
292 | !(ps2dev->flags & PS2_FLAG_CMD), timeout); | |
293 | } | |
294 | ||
218c1f76 DV |
295 | serio_pause_rx(ps2dev->serio); |
296 | ||
1da177e4 LT |
297 | if (param) |
298 | for (i = 0; i < receive; i++) | |
299 | param[i] = ps2dev->cmdbuf[(receive - 1) - i]; | |
300 | ||
b99e1f2a DT |
301 | if (ps2dev->cmdcnt && |
302 | (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) { | |
303 | rc = -EPROTO; | |
218c1f76 | 304 | goto out_reset_flags; |
b99e1f2a | 305 | } |
1da177e4 LT |
306 | |
307 | rc = 0; | |
308 | ||
218c1f76 | 309 | out_reset_flags: |
1da177e4 LT |
310 | ps2dev->flags = 0; |
311 | serio_continue_rx(ps2dev->serio); | |
312 | ||
147b903d DT |
313 | dev_dbg(&ps2dev->serio->dev, |
314 | "%02x [%*ph] - %x/%08lx [%*ph]\n", | |
315 | command & 0xff, send, send_param, | |
316 | ps2dev->nak, ps2dev->flags, | |
317 | receive, param ?: send_param); | |
318 | ||
b99e1f2a DT |
319 | /* |
320 | * ps_command() handles resends itself, so do not leak -EAGAIN | |
321 | * to the callers. | |
322 | */ | |
323 | return rc != -EAGAIN ? rc : -EPROTO; | |
fc69f4a6 TL |
324 | } |
325 | EXPORT_SYMBOL(__ps2_command); | |
326 | ||
b28bad65 | 327 | int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) |
fc69f4a6 TL |
328 | { |
329 | int rc; | |
330 | ||
181d683d | 331 | ps2_begin_command(ps2dev); |
fc69f4a6 | 332 | rc = __ps2_command(ps2dev, param, command); |
181d683d | 333 | ps2_end_command(ps2dev); |
fc69f4a6 | 334 | |
1da177e4 LT |
335 | return rc; |
336 | } | |
5206c0d5 | 337 | EXPORT_SYMBOL(ps2_command); |
1da177e4 | 338 | |
08be954b DT |
339 | /* |
340 | * ps2_sliced_command() sends an extended PS/2 command to the mouse | |
341 | * using sliced syntax, understood by advanced devices, such as Logitech | |
342 | * or Synaptics touchpads. The command is encoded as: | |
343 | * 0xE6 0xE8 rr 0xE8 ss 0xE8 tt 0xE8 uu where (rr*64)+(ss*16)+(tt*4)+uu | |
344 | * is the command. | |
345 | */ | |
346 | ||
347 | int ps2_sliced_command(struct ps2dev *ps2dev, u8 command) | |
348 | { | |
349 | int i; | |
350 | int retval; | |
351 | ||
352 | ps2_begin_command(ps2dev); | |
353 | ||
354 | retval = __ps2_command(ps2dev, NULL, PS2_CMD_SETSCALE11); | |
355 | if (retval) | |
356 | goto out; | |
357 | ||
358 | for (i = 6; i >= 0; i -= 2) { | |
359 | u8 d = (command >> i) & 3; | |
360 | retval = __ps2_command(ps2dev, &d, PS2_CMD_SETRES); | |
361 | if (retval) | |
362 | break; | |
363 | } | |
364 | ||
365 | out: | |
147b903d | 366 | dev_dbg(&ps2dev->serio->dev, "%02x - %d\n", command, retval); |
08be954b DT |
367 | ps2_end_command(ps2dev); |
368 | return retval; | |
369 | } | |
370 | EXPORT_SYMBOL(ps2_sliced_command); | |
371 | ||
1da177e4 LT |
372 | /* |
373 | * ps2_init() initializes ps2dev structure | |
374 | */ | |
375 | ||
376 | void ps2_init(struct ps2dev *ps2dev, struct serio *serio) | |
377 | { | |
c4e32e9f | 378 | mutex_init(&ps2dev->cmd_mutex); |
88aa0103 | 379 | lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth); |
1da177e4 LT |
380 | init_waitqueue_head(&ps2dev->wait); |
381 | ps2dev->serio = serio; | |
382 | } | |
5206c0d5 | 383 | EXPORT_SYMBOL(ps2_init); |
1da177e4 LT |
384 | |
385 | /* | |
386 | * ps2_handle_ack() is supposed to be used in interrupt handler | |
387 | * to properly process ACK/NAK of a command from a PS/2 device. | |
388 | */ | |
389 | ||
b28bad65 | 390 | bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data) |
1da177e4 LT |
391 | { |
392 | switch (data) { | |
d5e0d918 DT |
393 | case PS2_RET_ACK: |
394 | ps2dev->nak = 0; | |
395 | break; | |
396 | ||
397 | case PS2_RET_NAK: | |
398 | ps2dev->flags |= PS2_FLAG_NAK; | |
399 | ps2dev->nak = PS2_RET_NAK; | |
400 | break; | |
401 | ||
402 | case PS2_RET_ERR: | |
403 | if (ps2dev->flags & PS2_FLAG_NAK) { | |
404 | ps2dev->flags &= ~PS2_FLAG_NAK; | |
405 | ps2dev->nak = PS2_RET_ERR; | |
1da177e4 | 406 | break; |
d5e0d918 | 407 | } |
f7bda666 | 408 | fallthrough; |
1da177e4 | 409 | |
d5e0d918 DT |
410 | /* |
411 | * Workaround for mice which don't ACK the Get ID command. | |
412 | * These are valid mouse IDs that we recognize. | |
413 | */ | |
414 | case 0x00: | |
415 | case 0x03: | |
416 | case 0x04: | |
417 | if (ps2dev->flags & PS2_FLAG_WAITID) { | |
418 | ps2dev->nak = 0; | |
1da177e4 | 419 | break; |
d5e0d918 | 420 | } |
6f49c4f5 | 421 | fallthrough; |
d5e0d918 | 422 | default: |
29acc42e DT |
423 | /* |
424 | * Do not signal errors if we get unexpected reply while | |
425 | * waiting for an ACK to the initial (first) command byte: | |
426 | * the device might not be quiesced yet and continue | |
427 | * delivering data. | |
428 | * Note that we reset PS2_FLAG_WAITID flag, so the workaround | |
429 | * for mice not acknowledging the Get ID command only triggers | |
430 | * on the 1st byte; if device spews data we really want to see | |
431 | * a real ACK from it. | |
432 | */ | |
433 | dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data); | |
434 | ps2dev->flags &= ~PS2_FLAG_WAITID; | |
435 | return ps2dev->flags & PS2_FLAG_ACK_CMD; | |
1da177e4 LT |
436 | } |
437 | ||
a2d781fc DT |
438 | if (!ps2dev->nak) { |
439 | ps2dev->flags &= ~PS2_FLAG_NAK; | |
440 | if (ps2dev->cmdcnt) | |
441 | ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1; | |
442 | } | |
1da177e4 LT |
443 | |
444 | ps2dev->flags &= ~PS2_FLAG_ACK; | |
445 | wake_up(&ps2dev->wait); | |
446 | ||
447 | if (data != PS2_RET_ACK) | |
448 | ps2_handle_response(ps2dev, data); | |
449 | ||
b28bad65 | 450 | return true; |
1da177e4 | 451 | } |
5206c0d5 | 452 | EXPORT_SYMBOL(ps2_handle_ack); |
1da177e4 LT |
453 | |
454 | /* | |
455 | * ps2_handle_response() is supposed to be used in interrupt handler | |
456 | * to properly store device's response to a command and notify process | |
457 | * waiting for completion of the command. | |
458 | */ | |
459 | ||
b28bad65 | 460 | bool ps2_handle_response(struct ps2dev *ps2dev, u8 data) |
1da177e4 LT |
461 | { |
462 | if (ps2dev->cmdcnt) | |
463 | ps2dev->cmdbuf[--ps2dev->cmdcnt] = data; | |
464 | ||
465 | if (ps2dev->flags & PS2_FLAG_CMD1) { | |
466 | ps2dev->flags &= ~PS2_FLAG_CMD1; | |
467 | if (ps2dev->cmdcnt) | |
468 | wake_up(&ps2dev->wait); | |
469 | } | |
470 | ||
471 | if (!ps2dev->cmdcnt) { | |
472 | ps2dev->flags &= ~PS2_FLAG_CMD; | |
473 | wake_up(&ps2dev->wait); | |
474 | } | |
475 | ||
b28bad65 | 476 | return true; |
1da177e4 | 477 | } |
5206c0d5 | 478 | EXPORT_SYMBOL(ps2_handle_response); |
1da177e4 LT |
479 | |
480 | void ps2_cmd_aborted(struct ps2dev *ps2dev) | |
481 | { | |
482 | if (ps2dev->flags & PS2_FLAG_ACK) | |
483 | ps2dev->nak = 1; | |
484 | ||
485 | if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD)) | |
486 | wake_up(&ps2dev->wait); | |
487 | ||
a2d781fc DT |
488 | /* reset all flags except last nack */ |
489 | ps2dev->flags &= PS2_FLAG_NAK; | |
1da177e4 | 490 | } |
5206c0d5 | 491 | EXPORT_SYMBOL(ps2_cmd_aborted); |