Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-2.6-block.git] / drivers / input / serio / libps2.c
CommitLineData
1da177e4
LT
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>
d43c36dc 16#include <linux/sched.h>
1da177e4
LT
17#include <linux/interrupt.h>
18#include <linux/input.h>
19#include <linux/serio.h>
181d683d 20#include <linux/i8042.h>
1da177e4
LT
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
1da177e4 29/*
c611763d
DT
30 * 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.
1da177e4 33 *
c611763d 34 * ps2_sendbyte() can only be called from a process context.
1da177e4
LT
35 */
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}
5206c0d5 55EXPORT_SYMBOL(ps2_sendbyte);
1da177e4 56
181d683d
DT
57void 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
c611763d
DT
75/*
76 * 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
181d683d 87 ps2_begin_command(ps2dev);
c611763d
DT
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));
181d683d
DT
97
98 ps2_end_command(ps2dev);
c611763d 99}
5206c0d5 100EXPORT_SYMBOL(ps2_drain);
c611763d 101
905ab9d1
DT
102/*
103 * ps2_is_keyboard_id() checks received ID byte against the list of
104 * known keyboard IDs.
105 */
106
9807879b 107int ps2_is_keyboard_id(char id_byte)
905ab9d1 108{
c5a69d57 109 static const char keyboard_ids[] = {
905ab9d1
DT
110 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}
5206c0d5 120EXPORT_SYMBOL(ps2_is_keyboard_id);
905ab9d1
DT
121
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:
9807879b
DT
144 /*
145 * 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
905ab9d1
DT
157 /*
158 * 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
1da177e4
LT
176/*
177 * 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
fc69f4a6 183int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
1da177e4
LT
184{
185 int timeout;
186 int send = (command >> 12) & 0xf;
187 int receive = (command >> 8) & 0xf;
188 int rc = -1;
189 int i;
190
c611763d
DT
191 if (receive > sizeof(ps2dev->cmdbuf)) {
192 WARN_ON(1);
193 return -1;
194 }
195
95349fe8
DT
196 if (send && !param) {
197 WARN_ON(1);
198 return -1;
199 }
200
1da177e4
LT
201 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
83ae417b 212 * time before the ACK arrives.
1da177e4 213 */
c611763d
DT
214 if (ps2_sendbyte(ps2dev, command & 0xff,
215 command == PS2_CMD_RESET_BAT ? 1000 : 200))
216 goto out;
1da177e4
LT
217
218 for (i = 0; i < send; i++)
219 if (ps2_sendbyte(ps2dev, param[i], 200))
220 goto out;
221
222 /*
223 * The reset command takes a long time to execute.
224 */
225 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
226
227 timeout = wait_event_timeout(ps2dev->wait,
228 !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
229
a3ce6ea4 230 if (ps2dev->cmdcnt && !(ps2dev->flags & PS2_FLAG_CMD1)) {
1da177e4 231
905ab9d1 232 timeout = ps2_adjust_timeout(ps2dev, command, timeout);
1da177e4
LT
233 wait_event_timeout(ps2dev->wait,
234 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
235 }
236
237 if (param)
238 for (i = 0; i < receive; i++)
239 param[i] = ps2dev->cmdbuf[(receive - 1) - i];
240
241 if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
242 goto out;
243
244 rc = 0;
245
905ab9d1 246 out:
1da177e4
LT
247 serio_pause_rx(ps2dev->serio);
248 ps2dev->flags = 0;
249 serio_continue_rx(ps2dev->serio);
250
fc69f4a6
TL
251 return rc;
252}
253EXPORT_SYMBOL(__ps2_command);
254
255int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
256{
257 int rc;
258
181d683d 259 ps2_begin_command(ps2dev);
fc69f4a6 260 rc = __ps2_command(ps2dev, param, command);
181d683d 261 ps2_end_command(ps2dev);
fc69f4a6 262
1da177e4
LT
263 return rc;
264}
5206c0d5 265EXPORT_SYMBOL(ps2_command);
1da177e4 266
1da177e4
LT
267/*
268 * ps2_init() initializes ps2dev structure
269 */
270
271void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
272{
c4e32e9f 273 mutex_init(&ps2dev->cmd_mutex);
88aa0103 274 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
1da177e4
LT
275 init_waitqueue_head(&ps2dev->wait);
276 ps2dev->serio = serio;
277}
5206c0d5 278EXPORT_SYMBOL(ps2_init);
1da177e4
LT
279
280/*
281 * ps2_handle_ack() is supposed to be used in interrupt handler
282 * to properly process ACK/NAK of a command from a PS/2 device.
283 */
284
285int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
286{
287 switch (data) {
288 case PS2_RET_ACK:
289 ps2dev->nak = 0;
290 break;
291
292 case PS2_RET_NAK:
a2d781fc
DT
293 ps2dev->flags |= PS2_FLAG_NAK;
294 ps2dev->nak = PS2_RET_NAK;
1da177e4
LT
295 break;
296
a2d781fc
DT
297 case PS2_RET_ERR:
298 if (ps2dev->flags & PS2_FLAG_NAK) {
299 ps2dev->flags &= ~PS2_FLAG_NAK;
300 ps2dev->nak = PS2_RET_ERR;
301 break;
302 }
303
1da177e4
LT
304 /*
305 * Workaround for mice which don't ACK the Get ID command.
306 * These are valid mouse IDs that we recognize.
307 */
308 case 0x00:
309 case 0x03:
310 case 0x04:
311 if (ps2dev->flags & PS2_FLAG_WAITID) {
312 ps2dev->nak = 0;
313 break;
314 }
315 /* Fall through */
316 default:
317 return 0;
318 }
319
320
a2d781fc
DT
321 if (!ps2dev->nak) {
322 ps2dev->flags &= ~PS2_FLAG_NAK;
323 if (ps2dev->cmdcnt)
324 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
325 }
1da177e4
LT
326
327 ps2dev->flags &= ~PS2_FLAG_ACK;
328 wake_up(&ps2dev->wait);
329
330 if (data != PS2_RET_ACK)
331 ps2_handle_response(ps2dev, data);
332
333 return 1;
334}
5206c0d5 335EXPORT_SYMBOL(ps2_handle_ack);
1da177e4
LT
336
337/*
338 * ps2_handle_response() is supposed to be used in interrupt handler
339 * to properly store device's response to a command and notify process
340 * waiting for completion of the command.
341 */
342
343int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
344{
345 if (ps2dev->cmdcnt)
346 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
347
348 if (ps2dev->flags & PS2_FLAG_CMD1) {
349 ps2dev->flags &= ~PS2_FLAG_CMD1;
350 if (ps2dev->cmdcnt)
351 wake_up(&ps2dev->wait);
352 }
353
354 if (!ps2dev->cmdcnt) {
355 ps2dev->flags &= ~PS2_FLAG_CMD;
356 wake_up(&ps2dev->wait);
357 }
358
359 return 1;
360}
5206c0d5 361EXPORT_SYMBOL(ps2_handle_response);
1da177e4
LT
362
363void ps2_cmd_aborted(struct ps2dev *ps2dev)
364{
365 if (ps2dev->flags & PS2_FLAG_ACK)
366 ps2dev->nak = 1;
367
368 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
369 wake_up(&ps2dev->wait);
370
a2d781fc
DT
371 /* reset all flags except last nack */
372 ps2dev->flags &= PS2_FLAG_NAK;
1da177e4 373}
5206c0d5 374EXPORT_SYMBOL(ps2_cmd_aborted);