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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
25MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
26MODULE_DESCRIPTION("PS/2 driver library");
27MODULE_LICENSE("GPL");
28
29static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte,
30 unsigned int timeout, unsigned int max_attempts)
31 __releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock)
32{
33 int attempt = 0;
34 int error;
35
36 lockdep_assert_held(&ps2dev->serio->lock);
37
38 do {
39 ps2dev->nak = 1;
40 ps2dev->flags |= PS2_FLAG_ACK;
41
42 serio_continue_rx(ps2dev->serio);
43
44 error = serio_write(ps2dev->serio, byte);
45 if (error)
46 dev_dbg(&ps2dev->serio->dev,
47 "failed to write %#02x: %d\n", byte, error);
48 else
49 wait_event_timeout(ps2dev->wait,
50 !(ps2dev->flags & PS2_FLAG_ACK),
51 msecs_to_jiffies(timeout));
52
53 serio_pause_rx(ps2dev->serio);
54 } while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts);
55
56 ps2dev->flags &= ~PS2_FLAG_ACK;
57
58 if (!error) {
59 switch (ps2dev->nak) {
60 case 0:
61 break;
62 case PS2_RET_NAK:
63 error = -EAGAIN;
64 break;
65 case PS2_RET_ERR:
66 error = -EPROTO;
67 break;
68 default:
69 error = -EIO;
70 break;
71 }
72 }
73
74 if (error || attempt > 1)
75 dev_dbg(&ps2dev->serio->dev,
76 "%02x - %d (%x), attempt %d\n",
77 byte, error, ps2dev->nak, attempt);
78
79 return error;
80}
81
82
83
84
85
86
87
88
89
90int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
91{
92 int retval;
93
94 serio_pause_rx(ps2dev->serio);
95
96 retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1);
97 dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak);
98
99 serio_continue_rx(ps2dev->serio);
100
101 return retval;
102}
103EXPORT_SYMBOL(ps2_sendbyte);
104
105void ps2_begin_command(struct ps2dev *ps2dev)
106{
107 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
108
109 mutex_lock(m);
110}
111EXPORT_SYMBOL(ps2_begin_command);
112
113void ps2_end_command(struct ps2dev *ps2dev)
114{
115 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
116
117 mutex_unlock(m);
118}
119EXPORT_SYMBOL(ps2_end_command);
120
121
122
123
124
125
126void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout)
127{
128 if (maxbytes > sizeof(ps2dev->cmdbuf)) {
129 WARN_ON(1);
130 maxbytes = sizeof(ps2dev->cmdbuf);
131 }
132
133 ps2_begin_command(ps2dev);
134
135 serio_pause_rx(ps2dev->serio);
136 ps2dev->flags = PS2_FLAG_CMD;
137 ps2dev->cmdcnt = maxbytes;
138 serio_continue_rx(ps2dev->serio);
139
140 wait_event_timeout(ps2dev->wait,
141 !(ps2dev->flags & PS2_FLAG_CMD),
142 msecs_to_jiffies(timeout));
143
144 ps2_end_command(ps2dev);
145}
146EXPORT_SYMBOL(ps2_drain);
147
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151
152
153bool ps2_is_keyboard_id(u8 id_byte)
154{
155 static const u8 keyboard_ids[] = {
156 0xab,
157 0xac,
158 0x2b,
159 0x5d,
160 0x60,
161 0x47,
162 };
163
164 return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
165}
166EXPORT_SYMBOL(ps2_is_keyboard_id);
167
168
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172
173
174static int ps2_adjust_timeout(struct ps2dev *ps2dev,
175 unsigned int command, unsigned int timeout)
176{
177 switch (command) {
178 case PS2_CMD_RESET_BAT:
179
180
181
182
183
184
185
186 if (timeout > msecs_to_jiffies(100))
187 timeout = msecs_to_jiffies(100);
188 break;
189
190 case PS2_CMD_GETID:
191
192
193
194
195
196
197 if (ps2dev->cmdbuf[1] == 0xaa) {
198 serio_pause_rx(ps2dev->serio);
199 ps2dev->flags = 0;
200 serio_continue_rx(ps2dev->serio);
201 timeout = 0;
202 }
203
204
205
206
207
208 if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
209 serio_pause_rx(ps2dev->serio);
210 ps2dev->flags = ps2dev->cmdcnt = 0;
211 serio_continue_rx(ps2dev->serio);
212 timeout = 0;
213 }
214 break;
215
216 default:
217 break;
218 }
219
220 return timeout;
221}
222
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227
228
229
230int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
231{
232 unsigned int timeout;
233 unsigned int send = (command >> 12) & 0xf;
234 unsigned int receive = (command >> 8) & 0xf;
235 int rc;
236 int i;
237 u8 send_param[16];
238
239 if (receive > sizeof(ps2dev->cmdbuf)) {
240 WARN_ON(1);
241 return -EINVAL;
242 }
243
244 if (send && !param) {
245 WARN_ON(1);
246 return -EINVAL;
247 }
248
249 memcpy(send_param, param, send);
250
251 serio_pause_rx(ps2dev->serio);
252
253 ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
254 ps2dev->cmdcnt = receive;
255 if (receive && param)
256 for (i = 0; i < receive; i++)
257 ps2dev->cmdbuf[(receive - 1) - i] = param[i];
258
259
260 ps2dev->flags |= PS2_FLAG_ACK_CMD;
261
262
263
264
265
266
267 timeout = command == PS2_CMD_RESET_BAT ? 1000 : 200;
268
269 rc = ps2_do_sendbyte(ps2dev, command & 0xff, timeout, 2);
270 if (rc)
271 goto out_reset_flags;
272
273
274 ps2dev->flags &= ~PS2_FLAG_ACK_CMD;
275
276 for (i = 0; i < send; i++) {
277 rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2);
278 if (rc)
279 goto out_reset_flags;
280 }
281
282 serio_continue_rx(ps2dev->serio);
283
284
285
286
287 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
288
289 timeout = wait_event_timeout(ps2dev->wait,
290 !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
291
292 if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
293
294 timeout = ps2_adjust_timeout(ps2dev, command, timeout);
295 wait_event_timeout(ps2dev->wait,
296 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
297 }
298
299 serio_pause_rx(ps2dev->serio);
300
301 if (param)
302 for (i = 0; i < receive; i++)
303 param[i] = ps2dev->cmdbuf[(receive - 1) - i];
304
305 if (ps2dev->cmdcnt &&
306 (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) {
307 rc = -EPROTO;
308 goto out_reset_flags;
309 }
310
311 rc = 0;
312
313 out_reset_flags:
314 ps2dev->flags = 0;
315 serio_continue_rx(ps2dev->serio);
316
317 dev_dbg(&ps2dev->serio->dev,
318 "%02x [%*ph] - %x/%08lx [%*ph]\n",
319 command & 0xff, send, send_param,
320 ps2dev->nak, ps2dev->flags,
321 receive, param ?: send_param);
322
323
324
325
326
327 return rc != -EAGAIN ? rc : -EPROTO;
328}
329EXPORT_SYMBOL(__ps2_command);
330
331int ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
332{
333 int rc;
334
335 ps2_begin_command(ps2dev);
336 rc = __ps2_command(ps2dev, param, command);
337 ps2_end_command(ps2dev);
338
339 return rc;
340}
341EXPORT_SYMBOL(ps2_command);
342
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347
348
349
350
351int ps2_sliced_command(struct ps2dev *ps2dev, u8 command)
352{
353 int i;
354 int retval;
355
356 ps2_begin_command(ps2dev);
357
358 retval = __ps2_command(ps2dev, NULL, PS2_CMD_SETSCALE11);
359 if (retval)
360 goto out;
361
362 for (i = 6; i >= 0; i -= 2) {
363 u8 d = (command >> i) & 3;
364 retval = __ps2_command(ps2dev, &d, PS2_CMD_SETRES);
365 if (retval)
366 break;
367 }
368
369out:
370 dev_dbg(&ps2dev->serio->dev, "%02x - %d\n", command, retval);
371 ps2_end_command(ps2dev);
372 return retval;
373}
374EXPORT_SYMBOL(ps2_sliced_command);
375
376
377
378
379
380void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
381{
382 mutex_init(&ps2dev->cmd_mutex);
383 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
384 init_waitqueue_head(&ps2dev->wait);
385 ps2dev->serio = serio;
386}
387EXPORT_SYMBOL(ps2_init);
388
389
390
391
392
393
394bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data)
395{
396 switch (data) {
397 case PS2_RET_ACK:
398 ps2dev->nak = 0;
399 break;
400
401 case PS2_RET_NAK:
402 ps2dev->flags |= PS2_FLAG_NAK;
403 ps2dev->nak = PS2_RET_NAK;
404 break;
405
406 case PS2_RET_ERR:
407 if (ps2dev->flags & PS2_FLAG_NAK) {
408 ps2dev->flags &= ~PS2_FLAG_NAK;
409 ps2dev->nak = PS2_RET_ERR;
410 break;
411 }
412
413
414
415
416
417 case 0x00:
418 case 0x03:
419 case 0x04:
420 if (ps2dev->flags & PS2_FLAG_WAITID) {
421 ps2dev->nak = 0;
422 break;
423 }
424
425 default:
426
427
428
429
430
431
432
433
434
435
436 dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data);
437 ps2dev->flags &= ~PS2_FLAG_WAITID;
438 return ps2dev->flags & PS2_FLAG_ACK_CMD;
439 }
440
441 if (!ps2dev->nak) {
442 ps2dev->flags &= ~PS2_FLAG_NAK;
443 if (ps2dev->cmdcnt)
444 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
445 }
446
447 ps2dev->flags &= ~PS2_FLAG_ACK;
448 wake_up(&ps2dev->wait);
449
450 if (data != PS2_RET_ACK)
451 ps2_handle_response(ps2dev, data);
452
453 return true;
454}
455EXPORT_SYMBOL(ps2_handle_ack);
456
457
458
459
460
461
462
463bool ps2_handle_response(struct ps2dev *ps2dev, u8 data)
464{
465 if (ps2dev->cmdcnt)
466 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
467
468 if (ps2dev->flags & PS2_FLAG_CMD1) {
469 ps2dev->flags &= ~PS2_FLAG_CMD1;
470 if (ps2dev->cmdcnt)
471 wake_up(&ps2dev->wait);
472 }
473
474 if (!ps2dev->cmdcnt) {
475 ps2dev->flags &= ~PS2_FLAG_CMD;
476 wake_up(&ps2dev->wait);
477 }
478
479 return true;
480}
481EXPORT_SYMBOL(ps2_handle_response);
482
483void ps2_cmd_aborted(struct ps2dev *ps2dev)
484{
485 if (ps2dev->flags & PS2_FLAG_ACK)
486 ps2dev->nak = 1;
487
488 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
489 wake_up(&ps2dev->wait);
490
491
492 ps2dev->flags &= PS2_FLAG_NAK;
493}
494EXPORT_SYMBOL(ps2_cmd_aborted);
495