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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{
59 mutex_lock(&ps2dev->cmd_mutex);
60
61 if (i8042_check_port_owner(ps2dev->serio))
62 i8042_lock_chip();
63}
64EXPORT_SYMBOL(ps2_begin_command);
65
66void ps2_end_command(struct ps2dev *ps2dev)
67{
68 if (i8042_check_port_owner(ps2dev->serio))
69 i8042_unlock_chip();
70
71 mutex_unlock(&ps2dev->cmd_mutex);
72}
73EXPORT_SYMBOL(ps2_end_command);
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075/*
Dmitry Torokhovc6117632005-06-01 02:39:51 -050076 * ps2_drain() waits for device to transmit requested number of bytes
77 * and discards them.
78 */
79
80void 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
Dmitry Torokhov181d6832009-09-16 01:06:43 -070087 ps2_begin_command(ps2dev);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050088
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));
Dmitry Torokhov181d6832009-09-16 01:06:43 -070097
98 ps2_end_command(ps2dev);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050099}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400100EXPORT_SYMBOL(ps2_drain);
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500101
102/*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500103 * ps2_is_keyboard_id() checks received ID byte against the list of
104 * known keyboard IDs.
105 */
106
Dmitry Torokhov98078792006-09-14 01:31:27 -0400107int ps2_is_keyboard_id(char id_byte)
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500108{
Tobias Klauserc5a69d52007-02-17 20:11:19 +0100109 static const char keyboard_ids[] = {
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500110 0xab, /* Regular keyboards */
111 0xac, /* NCD Sun keyboard */
112 0x2b, /* Trust keyboard, translated */
113 0x5d, /* Trust keyboard */
114 0x60, /* NMB SGI keyboard, translated */
115 0x47, /* NMB SGI keyboard */
116 };
117
118 return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
119}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400120EXPORT_SYMBOL(ps2_is_keyboard_id);
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500121
122/*
123 * ps2_adjust_timeout() is called after receiving 1st byte of command
124 * response and tries to reduce remaining timeout to speed up command
125 * completion.
126 */
127
128static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout)
129{
130 switch (command) {
131 case PS2_CMD_RESET_BAT:
132 /*
133 * Device has sent the first response byte after
134 * reset command, reset is thus done, so we can
135 * shorten the timeout.
136 * The next byte will come soon (keyboard) or not
137 * at all (mouse).
138 */
139 if (timeout > msecs_to_jiffies(100))
140 timeout = msecs_to_jiffies(100);
141 break;
142
143 case PS2_CMD_GETID:
144 /*
Dmitry Torokhov98078792006-09-14 01:31:27 -0400145 * Microsoft Natural Elite keyboard responds to
146 * the GET ID command as it were a mouse, with
147 * a single byte. Fail the command so atkbd will
148 * use alternative probe to detect it.
149 */
150 if (ps2dev->cmdbuf[1] == 0xaa) {
151 serio_pause_rx(ps2dev->serio);
152 ps2dev->flags = 0;
153 serio_continue_rx(ps2dev->serio);
154 timeout = 0;
155 }
156
157 /*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500158 * If device behind the port is not a keyboard there
159 * won't be 2nd byte of ID response.
160 */
161 if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
162 serio_pause_rx(ps2dev->serio);
163 ps2dev->flags = ps2dev->cmdcnt = 0;
164 serio_continue_rx(ps2dev->serio);
165 timeout = 0;
166 }
167 break;
168
169 default:
170 break;
171 }
172
173 return timeout;
174}
175
176/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 * ps2_command() sends a command and its parameters to the mouse,
178 * then waits for the response and puts it in the param array.
179 *
180 * ps2_command() can only be called from a process context
181 */
182
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700183int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
185 int timeout;
186 int send = (command >> 12) & 0xf;
187 int receive = (command >> 8) & 0xf;
188 int rc = -1;
189 int i;
190
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500191 if (receive > sizeof(ps2dev->cmdbuf)) {
192 WARN_ON(1);
193 return -1;
194 }
195
Dmitry Torokhov95349fe2006-07-06 23:54:48 -0400196 if (send && !param) {
197 WARN_ON(1);
198 return -1;
199 }
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 serio_pause_rx(ps2dev->serio);
202 ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
203 ps2dev->cmdcnt = receive;
204 if (receive && param)
205 for (i = 0; i < receive; i++)
206 ps2dev->cmdbuf[(receive - 1) - i] = param[i];
207 serio_continue_rx(ps2dev->serio);
208
209 /*
210 * Some devices (Synaptics) peform the reset before
211 * ACKing the reset command, and so it can take a long
Justin P. Mattock83ae4172011-06-22 23:29:19 -0700212 * time before the ACK arrives.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 */
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500214 if (ps2_sendbyte(ps2dev, command & 0xff,
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700215 command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
216 serio_pause_rx(ps2dev->serio);
217 goto out_reset_flags;
218 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700220 for (i = 0; i < send; i++) {
221 if (ps2_sendbyte(ps2dev, param[i], 200)) {
222 serio_pause_rx(ps2dev->serio);
223 goto out_reset_flags;
224 }
225 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 /*
228 * The reset command takes a long time to execute.
229 */
230 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
231
232 timeout = wait_event_timeout(ps2dev->wait,
233 !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
234
Dmitry Torokhova3ce6ea2009-05-28 09:51:31 -0700235 if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500237 timeout = ps2_adjust_timeout(ps2dev, command, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 wait_event_timeout(ps2dev->wait,
239 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
240 }
241
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700242 serio_pause_rx(ps2dev->serio);
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 if (param)
245 for (i = 0; i < receive; i++)
246 param[i] = ps2dev->cmdbuf[(receive - 1) - i];
247
248 if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700249 goto out_reset_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251 rc = 0;
252
Dmitry Vyukov218c1f72015-09-29 15:54:58 -0700253 out_reset_flags:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 ps2dev->flags = 0;
255 serio_continue_rx(ps2dev->serio);
256
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700257 return rc;
258}
259EXPORT_SYMBOL(__ps2_command);
260
261int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
262{
263 int rc;
264
Dmitry Torokhov181d6832009-09-16 01:06:43 -0700265 ps2_begin_command(ps2dev);
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700266 rc = __ps2_command(ps2dev, param, command);
Dmitry Torokhov181d6832009-09-16 01:06:43 -0700267 ps2_end_command(ps2dev);
Tai-hwa Liangfc69f4a2009-05-10 18:15:39 -0700268
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 return rc;
270}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400271EXPORT_SYMBOL(ps2_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 * ps2_init() initializes ps2dev structure
275 */
276
277void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
278{
Arjan van de Venc4e32e92006-02-19 00:21:55 -0500279 mutex_init(&ps2dev->cmd_mutex);
Jiri Kosina88aa0102006-10-11 01:45:31 -0400280 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 init_waitqueue_head(&ps2dev->wait);
282 ps2dev->serio = serio;
283}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400284EXPORT_SYMBOL(ps2_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
286/*
287 * ps2_handle_ack() is supposed to be used in interrupt handler
288 * to properly process ACK/NAK of a command from a PS/2 device.
289 */
290
291int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
292{
293 switch (data) {
294 case PS2_RET_ACK:
295 ps2dev->nak = 0;
296 break;
297
298 case PS2_RET_NAK:
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500299 ps2dev->flags |= PS2_FLAG_NAK;
300 ps2dev->nak = PS2_RET_NAK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 break;
302
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500303 case PS2_RET_ERR:
304 if (ps2dev->flags & PS2_FLAG_NAK) {
305 ps2dev->flags &= ~PS2_FLAG_NAK;
306 ps2dev->nak = PS2_RET_ERR;
307 break;
308 }
309
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 /*
311 * Workaround for mice which don't ACK the Get ID command.
312 * These are valid mouse IDs that we recognize.
313 */
314 case 0x00:
315 case 0x03:
316 case 0x04:
317 if (ps2dev->flags & PS2_FLAG_WAITID) {
318 ps2dev->nak = 0;
319 break;
320 }
321 /* Fall through */
322 default:
323 return 0;
324 }
325
326
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500327 if (!ps2dev->nak) {
328 ps2dev->flags &= ~PS2_FLAG_NAK;
329 if (ps2dev->cmdcnt)
330 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
331 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
333 ps2dev->flags &= ~PS2_FLAG_ACK;
334 wake_up(&ps2dev->wait);
335
336 if (data != PS2_RET_ACK)
337 ps2_handle_response(ps2dev, data);
338
339 return 1;
340}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400341EXPORT_SYMBOL(ps2_handle_ack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
343/*
344 * ps2_handle_response() is supposed to be used in interrupt handler
345 * to properly store device's response to a command and notify process
346 * waiting for completion of the command.
347 */
348
349int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
350{
351 if (ps2dev->cmdcnt)
352 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
353
354 if (ps2dev->flags & PS2_FLAG_CMD1) {
355 ps2dev->flags &= ~PS2_FLAG_CMD1;
356 if (ps2dev->cmdcnt)
357 wake_up(&ps2dev->wait);
358 }
359
360 if (!ps2dev->cmdcnt) {
361 ps2dev->flags &= ~PS2_FLAG_CMD;
362 wake_up(&ps2dev->wait);
363 }
364
365 return 1;
366}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400367EXPORT_SYMBOL(ps2_handle_response);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
369void ps2_cmd_aborted(struct ps2dev *ps2dev)
370{
371 if (ps2dev->flags & PS2_FLAG_ACK)
372 ps2dev->nak = 1;
373
374 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
375 wake_up(&ps2dev->wait);
376
Dmitry Torokhova2d781f2008-11-19 17:02:24 -0500377 /* reset all flags except last nack */
378 ps2dev->flags &= PS2_FLAG_NAK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400380EXPORT_SYMBOL(ps2_cmd_aborted);