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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>
16#include <linux/moduleparam.h>
17#include <linux/slab.h>
18#include <linux/interrupt.h>
19#include <linux/input.h>
20#include <linux/serio.h>
21#include <linux/init.h>
22#include <linux/libps2.h>
23
24#define DRIVER_DESC "PS/2 driver library"
25
26MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
27MODULE_DESCRIPTION("PS/2 driver library");
28MODULE_LICENSE("GPL");
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030/* Work structure to schedule execution of a command */
31struct ps2work {
32 struct work_struct work;
33 struct ps2dev *ps2dev;
34 int command;
35 unsigned char param[0];
36};
37
38
39/*
Dmitry Torokhovc6117632005-06-01 02:39:51 -050040 * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
41 * It doesn't handle retransmission, though it could - because if there
42 * is a need for retransmissions device has to be replaced anyway.
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 *
Dmitry Torokhovc6117632005-06-01 02:39:51 -050044 * ps2_sendbyte() can only be called from a process context.
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 */
46
47int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
48{
49 serio_pause_rx(ps2dev->serio);
50 ps2dev->nak = 1;
51 ps2dev->flags |= PS2_FLAG_ACK;
52 serio_continue_rx(ps2dev->serio);
53
54 if (serio_write(ps2dev->serio, byte) == 0)
55 wait_event_timeout(ps2dev->wait,
56 !(ps2dev->flags & PS2_FLAG_ACK),
57 msecs_to_jiffies(timeout));
58
59 serio_pause_rx(ps2dev->serio);
60 ps2dev->flags &= ~PS2_FLAG_ACK;
61 serio_continue_rx(ps2dev->serio);
62
63 return -ps2dev->nak;
64}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -040065EXPORT_SYMBOL(ps2_sendbyte);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67/*
Dmitry Torokhovc6117632005-06-01 02:39:51 -050068 * ps2_drain() waits for device to transmit requested number of bytes
69 * and discards them.
70 */
71
72void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
73{
74 if (maxbytes > sizeof(ps2dev->cmdbuf)) {
75 WARN_ON(1);
76 maxbytes = sizeof(ps2dev->cmdbuf);
77 }
78
Arjan van de Venc4e32e92006-02-19 00:21:55 -050079 mutex_lock(&ps2dev->cmd_mutex);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050080
81 serio_pause_rx(ps2dev->serio);
82 ps2dev->flags = PS2_FLAG_CMD;
83 ps2dev->cmdcnt = maxbytes;
84 serio_continue_rx(ps2dev->serio);
85
86 wait_event_timeout(ps2dev->wait,
87 !(ps2dev->flags & PS2_FLAG_CMD),
88 msecs_to_jiffies(timeout));
Arjan van de Venc4e32e92006-02-19 00:21:55 -050089 mutex_unlock(&ps2dev->cmd_mutex);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050090}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -040091EXPORT_SYMBOL(ps2_drain);
Dmitry Torokhovc6117632005-06-01 02:39:51 -050092
93/*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -050094 * ps2_is_keyboard_id() checks received ID byte against the list of
95 * known keyboard IDs.
96 */
97
Dmitry Torokhov98078792006-09-14 01:31:27 -040098int ps2_is_keyboard_id(char id_byte)
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -050099{
Tobias Klauserc5a69d52007-02-17 20:11:19 +0100100 static const char keyboard_ids[] = {
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500101 0xab, /* Regular keyboards */
102 0xac, /* NCD Sun keyboard */
103 0x2b, /* Trust keyboard, translated */
104 0x5d, /* Trust keyboard */
105 0x60, /* NMB SGI keyboard, translated */
106 0x47, /* NMB SGI keyboard */
107 };
108
109 return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
110}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400111EXPORT_SYMBOL(ps2_is_keyboard_id);
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500112
113/*
114 * ps2_adjust_timeout() is called after receiving 1st byte of command
115 * response and tries to reduce remaining timeout to speed up command
116 * completion.
117 */
118
119static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout)
120{
121 switch (command) {
122 case PS2_CMD_RESET_BAT:
123 /*
124 * Device has sent the first response byte after
125 * reset command, reset is thus done, so we can
126 * shorten the timeout.
127 * The next byte will come soon (keyboard) or not
128 * at all (mouse).
129 */
130 if (timeout > msecs_to_jiffies(100))
131 timeout = msecs_to_jiffies(100);
132 break;
133
134 case PS2_CMD_GETID:
135 /*
Dmitry Torokhov98078792006-09-14 01:31:27 -0400136 * Microsoft Natural Elite keyboard responds to
137 * the GET ID command as it were a mouse, with
138 * a single byte. Fail the command so atkbd will
139 * use alternative probe to detect it.
140 */
141 if (ps2dev->cmdbuf[1] == 0xaa) {
142 serio_pause_rx(ps2dev->serio);
143 ps2dev->flags = 0;
144 serio_continue_rx(ps2dev->serio);
145 timeout = 0;
146 }
147
148 /*
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500149 * If device behind the port is not a keyboard there
150 * won't be 2nd byte of ID response.
151 */
152 if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
153 serio_pause_rx(ps2dev->serio);
154 ps2dev->flags = ps2dev->cmdcnt = 0;
155 serio_continue_rx(ps2dev->serio);
156 timeout = 0;
157 }
158 break;
159
160 default:
161 break;
162 }
163
164 return timeout;
165}
166
167/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 * ps2_command() sends a command and its parameters to the mouse,
169 * then waits for the response and puts it in the param array.
170 *
171 * ps2_command() can only be called from a process context
172 */
173
174int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
175{
176 int timeout;
177 int send = (command >> 12) & 0xf;
178 int receive = (command >> 8) & 0xf;
179 int rc = -1;
180 int i;
181
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500182 if (receive > sizeof(ps2dev->cmdbuf)) {
183 WARN_ON(1);
184 return -1;
185 }
186
Dmitry Torokhov95349fe2006-07-06 23:54:48 -0400187 if (send && !param) {
188 WARN_ON(1);
189 return -1;
190 }
191
Jiri Kosina88aa0102006-10-11 01:45:31 -0400192 mutex_lock(&ps2dev->cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 serio_pause_rx(ps2dev->serio);
195 ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
196 ps2dev->cmdcnt = receive;
197 if (receive && param)
198 for (i = 0; i < receive; i++)
199 ps2dev->cmdbuf[(receive - 1) - i] = param[i];
200 serio_continue_rx(ps2dev->serio);
201
202 /*
203 * Some devices (Synaptics) peform the reset before
204 * ACKing the reset command, and so it can take a long
205 * time before the ACK arrrives.
206 */
Dmitry Torokhovc6117632005-06-01 02:39:51 -0500207 if (ps2_sendbyte(ps2dev, command & 0xff,
208 command == PS2_CMD_RESET_BAT ? 1000 : 200))
209 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 for (i = 0; i < send; i++)
212 if (ps2_sendbyte(ps2dev, param[i], 200))
213 goto out;
214
215 /*
216 * The reset command takes a long time to execute.
217 */
218 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
219
220 timeout = wait_event_timeout(ps2dev->wait,
221 !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
222
223 if (ps2dev->cmdcnt && timeout > 0) {
224
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500225 timeout = ps2_adjust_timeout(ps2dev, command, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 wait_event_timeout(ps2dev->wait,
227 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
228 }
229
230 if (param)
231 for (i = 0; i < receive; i++)
232 param[i] = ps2dev->cmdbuf[(receive - 1) - i];
233
234 if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
235 goto out;
236
237 rc = 0;
238
Dmitry Torokhov905ab9d2005-06-01 02:39:53 -0500239 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 serio_pause_rx(ps2dev->serio);
241 ps2dev->flags = 0;
242 serio_continue_rx(ps2dev->serio);
243
Arjan van de Venc4e32e92006-02-19 00:21:55 -0500244 mutex_unlock(&ps2dev->cmd_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 return rc;
246}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400247EXPORT_SYMBOL(ps2_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249/*
250 * ps2_execute_scheduled_command() sends a command, previously scheduled by
251 * ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.)
252 */
253
David Howells65f27f32006-11-22 14:55:48 +0000254static void ps2_execute_scheduled_command(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
David Howells65f27f32006-11-22 14:55:48 +0000256 struct ps2work *ps2work = container_of(work, struct ps2work, work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258 ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command);
259 kfree(ps2work);
260}
261
262/*
263 * ps2_schedule_command() allows to schedule delayed execution of a PS/2
264 * command and can be used to issue a command from an interrupt or softirq
265 * context.
266 */
267
268int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command)
269{
270 struct ps2work *ps2work;
271 int send = (command >> 12) & 0xf;
272 int receive = (command >> 8) & 0xf;
273
274 if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC)))
275 return -1;
276
277 memset(ps2work, 0, sizeof(struct ps2work));
278 ps2work->ps2dev = ps2dev;
279 ps2work->command = command;
280 memcpy(ps2work->param, param, send);
David Howells65f27f32006-11-22 14:55:48 +0000281 INIT_WORK(&ps2work->work, ps2_execute_scheduled_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 if (!schedule_work(&ps2work->work)) {
284 kfree(ps2work);
285 return -1;
286 }
287
288 return 0;
289}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400290EXPORT_SYMBOL(ps2_schedule_command);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292/*
293 * ps2_init() initializes ps2dev structure
294 */
295
296void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
297{
Arjan van de Venc4e32e92006-02-19 00:21:55 -0500298 mutex_init(&ps2dev->cmd_mutex);
Jiri Kosina88aa0102006-10-11 01:45:31 -0400299 lockdep_set_subclass(&ps2dev->cmd_mutex, serio->depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 init_waitqueue_head(&ps2dev->wait);
301 ps2dev->serio = serio;
302}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400303EXPORT_SYMBOL(ps2_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304
305/*
306 * ps2_handle_ack() is supposed to be used in interrupt handler
307 * to properly process ACK/NAK of a command from a PS/2 device.
308 */
309
310int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
311{
312 switch (data) {
313 case PS2_RET_ACK:
314 ps2dev->nak = 0;
315 break;
316
317 case PS2_RET_NAK:
318 ps2dev->nak = 1;
319 break;
320
321 /*
322 * Workaround for mice which don't ACK the Get ID command.
323 * These are valid mouse IDs that we recognize.
324 */
325 case 0x00:
326 case 0x03:
327 case 0x04:
328 if (ps2dev->flags & PS2_FLAG_WAITID) {
329 ps2dev->nak = 0;
330 break;
331 }
332 /* Fall through */
333 default:
334 return 0;
335 }
336
337
338 if (!ps2dev->nak && ps2dev->cmdcnt)
339 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
340
341 ps2dev->flags &= ~PS2_FLAG_ACK;
342 wake_up(&ps2dev->wait);
343
344 if (data != PS2_RET_ACK)
345 ps2_handle_response(ps2dev, data);
346
347 return 1;
348}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400349EXPORT_SYMBOL(ps2_handle_ack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351/*
352 * ps2_handle_response() is supposed to be used in interrupt handler
353 * to properly store device's response to a command and notify process
354 * waiting for completion of the command.
355 */
356
357int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
358{
359 if (ps2dev->cmdcnt)
360 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
361
362 if (ps2dev->flags & PS2_FLAG_CMD1) {
363 ps2dev->flags &= ~PS2_FLAG_CMD1;
364 if (ps2dev->cmdcnt)
365 wake_up(&ps2dev->wait);
366 }
367
368 if (!ps2dev->cmdcnt) {
369 ps2dev->flags &= ~PS2_FLAG_CMD;
370 wake_up(&ps2dev->wait);
371 }
372
373 return 1;
374}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400375EXPORT_SYMBOL(ps2_handle_response);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
377void ps2_cmd_aborted(struct ps2dev *ps2dev)
378{
379 if (ps2dev->flags & PS2_FLAG_ACK)
380 ps2dev->nak = 1;
381
382 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
383 wake_up(&ps2dev->wait);
384
385 ps2dev->flags = 0;
386}
Dmitry Torokhov5206c0d2006-09-14 01:31:40 -0400387EXPORT_SYMBOL(ps2_cmd_aborted);