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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040016#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/interrupt.h>
18#include <linux/input.h>
19#include <linux/serio.h>
Dmitry Torokhov181d6832009-09-16 01:06:43 -070020#include <linux/i8042.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070029/*
Dmitry Torokhovc6117632005-06-01 02:39:51 -050030 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 *
Dmitry Torokhovc6117632005-06-01 02:39:51 -050034 * ps2_sendbyte() can only be called from a process context.
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 */
36
37int 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}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -040055EXPORT_SYMBOL(ps2_sendbyte);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Dmitry Torokhov181d6832009-09-16 01:06:43 -070057void ps2_begin_command(struct ps2dev *ps2dev)
58{
Dmitry Torokhov40974612016-07-25 11:36:54 -070059 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
Dmitry Torokhov181d6832009-09-16 01:06:43 -070060
Dmitry Torokhov40974612016-07-25 11:36:54 -070061 mutex_lock(m);
Dmitry Torokhov181d6832009-09-16 01:06:43 -070062}
63EXPORT_SYMBOL(ps2_begin_command);
64
65void ps2_end_command(struct ps2dev *ps2dev)
66{
Dmitry Torokhov40974612016-07-25 11:36:54 -070067 struct mutex *m = ps2dev->serio->ps2_cmd_mutex ?: &ps2dev->cmd_mutex;
Dmitry Torokhov181d6832009-09-16 01:06:43 -070068
Dmitry Torokhov40974612016-07-25 11:36:54 -070069 mutex_unlock(m);
Dmitry Torokhov181d6832009-09-16 01:06:43 -070070}
71EXPORT_SYMBOL(ps2_end_command);
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073/*
Dmitry Torokhovc6117632005-06-01 02:39:51 -050074 * ps2_drain() waits for device to transmit requested number of bytes
75 * and discards them.
76 */
77
78void 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
Dmitry Torokhov181d6832009-09-16 01:06:43 -070085 ps2_begin_command(ps2dev);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050086
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));
Dmitry Torokhov181d6832009-09-16 01:06:43 -070095
96 ps2_end_command(ps2dev);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050097}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -040098EXPORT_SYMBOL(ps2_drain);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050099
100/*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500101 * ps2_is_keyboard_id() checks received ID byte against the list of
102 * known keyboard IDs.
103 */
104
Dmitry Torokhov98078792006-09-14 01:31:27 -0400105int ps2_is_keyboard_id(char id_byte)
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500106{
Tobias Klauserc5a69d52007-02-17 20:11:19 +0100107 static const char keyboard_ids[] = {
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500108 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}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400118EXPORT_SYMBOL(ps2_is_keyboard_id);
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500119
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
126static 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 /*
Dmitry Torokhov98078792006-09-14 01:31:27 -0400143 * 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 /*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500156 * 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/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 * 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
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700181int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
183 int timeout;
184 int send = (command >> 12) & 0xf;
185 int receive = (command >> 8) & 0xf;
186 int rc = -1;
187 int i;
188
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500189 if (receive > sizeof(ps2dev->cmdbuf)) {
190 WARN_ON(1);
191 return -1;
192 }
193
Dmitry Torokhov95349fe2006-07-06 23:54:48 -0400194 if (send && !param) {
195 WARN_ON(1);
196 return -1;
197 }
198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 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
Justin P. Mattock83ae4172011-06-22 23:29:19 -0700210 * time before the ACK arrives.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 */
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500212 if (ps2_sendbyte(ps2dev, command & 0xff,
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700213 command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
214 serio_pause_rx(ps2dev->serio);
215 goto out_reset_flags;
216 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700218 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
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
Dmitry Torokhova3ce6ea2009-05-28 09:51:31 -0700233 if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500235 timeout = ps2_adjust_timeout(ps2dev, command, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 wait_event_timeout(ps2dev->wait,
237 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
238 }
239
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700240 serio_pause_rx(ps2dev->serio);
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 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))
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700247 goto out_reset_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 rc = 0;
250
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700251 out_reset_flags:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 ps2dev->flags = 0;
253 serio_continue_rx(ps2dev->serio);
254
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700255 return rc;
256}
257EXPORT_SYMBOL(__ps2_command);
258
259int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
260{
261 int rc;
262
Dmitry Torokhov181d6832009-09-16 01:06:43 -0700263 ps2_begin_command(ps2dev);
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700264 rc = __ps2_command(ps2dev, param, command);
Dmitry Torokhov181d6832009-09-16 01:06:43 -0700265 ps2_end_command(ps2dev);
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 return rc;
268}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400269EXPORT_SYMBOL(ps2_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 * ps2_init() initializes ps2dev structure
273 */
274
275void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
276{
Arjan van de Venc4e32e92006-02-19 00:21:55 -0500277 mutex_init(&ps2dev->cmd_mutex);
Jiri Kosina88aa0102006-10-11 01:45:31 -0400278 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 init_waitqueue_head(&ps2dev->wait);
280 ps2dev->serio = serio;
281}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400282EXPORT_SYMBOL(ps2_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
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
289int 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:
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500297 ps2dev->flags |= PS2_FLAG_NAK;
298 ps2dev->nak = PS2_RET_NAK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 break;
300
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500301 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 /*
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
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500325 if (!ps2dev->nak) {
326 ps2dev->flags &= ~PS2_FLAG_NAK;
327 if (ps2dev->cmdcnt)
328 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
329 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
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}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400339EXPORT_SYMBOL(ps2_handle_ack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
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
347int 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}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400365EXPORT_SYMBOL(ps2_handle_response);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
367void 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
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500375 /* reset all flags except last nack */
376 ps2dev->flags &= PS2_FLAG_NAK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400378EXPORT_SYMBOL(ps2_cmd_aborted);