aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/serio/libps2.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/input/serio/libps2.c')
-rw-r--r--drivers/input/serio/libps2.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
new file mode 100644
index 000000000000..c978657068c5
--- /dev/null
+++ b/drivers/input/serio/libps2.c
@@ -0,0 +1,305 @@
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>
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
30EXPORT_SYMBOL(ps2_init);
31EXPORT_SYMBOL(ps2_sendbyte);
32EXPORT_SYMBOL(ps2_command);
33EXPORT_SYMBOL(ps2_schedule_command);
34EXPORT_SYMBOL(ps2_handle_ack);
35EXPORT_SYMBOL(ps2_handle_response);
36EXPORT_SYMBOL(ps2_cmd_aborted);
37
38/* Work structure to schedule execution of a command */
39struct ps2work {
40 struct work_struct work;
41 struct ps2dev *ps2dev;
42 int command;
43 unsigned char param[0];
44};
45
46
47/*
48 * ps2_sendbyte() sends a byte to the mouse, and waits for acknowledge.
49 * It doesn't handle retransmission, though it could - because when there would
50 * be need for retransmissions, the mouse has to be replaced anyway.
51 *
52 * ps2_sendbyte() can only be called from a process context
53 */
54
55int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
56{
57 serio_pause_rx(ps2dev->serio);
58 ps2dev->nak = 1;
59 ps2dev->flags |= PS2_FLAG_ACK;
60 serio_continue_rx(ps2dev->serio);
61
62 if (serio_write(ps2dev->serio, byte) == 0)
63 wait_event_timeout(ps2dev->wait,
64 !(ps2dev->flags & PS2_FLAG_ACK),
65 msecs_to_jiffies(timeout));
66
67 serio_pause_rx(ps2dev->serio);
68 ps2dev->flags &= ~PS2_FLAG_ACK;
69 serio_continue_rx(ps2dev->serio);
70
71 return -ps2dev->nak;
72}
73
74/*
75 * ps2_command() sends a command and its parameters to the mouse,
76 * then waits for the response and puts it in the param array.
77 *
78 * ps2_command() can only be called from a process context
79 */
80
81int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
82{
83 int timeout;
84 int send = (command >> 12) & 0xf;
85 int receive = (command >> 8) & 0xf;
86 int rc = -1;
87 int i;
88
89 down(&ps2dev->cmd_sem);
90
91 serio_pause_rx(ps2dev->serio);
92 ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
93 ps2dev->cmdcnt = receive;
94 if (receive && param)
95 for (i = 0; i < receive; i++)
96 ps2dev->cmdbuf[(receive - 1) - i] = param[i];
97 serio_continue_rx(ps2dev->serio);
98
99 /*
100 * Some devices (Synaptics) peform the reset before
101 * ACKing the reset command, and so it can take a long
102 * time before the ACK arrrives.
103 */
104 if (command & 0xff)
105 if (ps2_sendbyte(ps2dev, command & 0xff,
106 command == PS2_CMD_RESET_BAT ? 1000 : 200))
107 goto out;
108
109 for (i = 0; i < send; i++)
110 if (ps2_sendbyte(ps2dev, param[i], 200))
111 goto out;
112
113 /*
114 * The reset command takes a long time to execute.
115 */
116 timeout = msecs_to_jiffies(command == PS2_CMD_RESET_BAT ? 4000 : 500);
117
118 timeout = wait_event_timeout(ps2dev->wait,
119 !(ps2dev->flags & PS2_FLAG_CMD1), timeout);
120
121 if (ps2dev->cmdcnt && timeout > 0) {
122
123 if (command == PS2_CMD_RESET_BAT && timeout > msecs_to_jiffies(100)) {
124 /*
125 * Device has sent the first response byte
126 * after a reset command, reset is thus done,
127 * shorten the timeout. The next byte will come
128 * soon (keyboard) or not at all (mouse).
129 */
130 timeout = msecs_to_jiffies(100);
131 }
132
133 if (command == PS2_CMD_GETID &&
134 ps2dev->cmdbuf[receive - 1] != 0xab && /* Regular keyboards */
135 ps2dev->cmdbuf[receive - 1] != 0xac && /* NCD Sun keyboard */
136 ps2dev->cmdbuf[receive - 1] != 0x2b && /* Trust keyboard, translated */
137 ps2dev->cmdbuf[receive - 1] != 0x5d && /* Trust keyboard */
138 ps2dev->cmdbuf[receive - 1] != 0x60 && /* NMB SGI keyboard, translated */
139 ps2dev->cmdbuf[receive - 1] != 0x47) { /* NMB SGI keyboard */
140 /*
141 * Device behind the port is not a keyboard
142 * so we don't need to wait for the 2nd byte
143 * of ID response.
144 */
145 serio_pause_rx(ps2dev->serio);
146 ps2dev->flags = ps2dev->cmdcnt = 0;
147 serio_continue_rx(ps2dev->serio);
148 }
149
150 wait_event_timeout(ps2dev->wait,
151 !(ps2dev->flags & PS2_FLAG_CMD), timeout);
152 }
153
154 if (param)
155 for (i = 0; i < receive; i++)
156 param[i] = ps2dev->cmdbuf[(receive - 1) - i];
157
158 if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
159 goto out;
160
161 rc = 0;
162
163out:
164 serio_pause_rx(ps2dev->serio);
165 ps2dev->flags = 0;
166 serio_continue_rx(ps2dev->serio);
167
168 up(&ps2dev->cmd_sem);
169 return rc;
170}
171
172/*
173 * ps2_execute_scheduled_command() sends a command, previously scheduled by
174 * ps2_schedule_command(), to a PS/2 device (keyboard, mouse, etc.)
175 */
176
177static void ps2_execute_scheduled_command(void *data)
178{
179 struct ps2work *ps2work = data;
180
181 ps2_command(ps2work->ps2dev, ps2work->param, ps2work->command);
182 kfree(ps2work);
183}
184
185/*
186 * ps2_schedule_command() allows to schedule delayed execution of a PS/2
187 * command and can be used to issue a command from an interrupt or softirq
188 * context.
189 */
190
191int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command)
192{
193 struct ps2work *ps2work;
194 int send = (command >> 12) & 0xf;
195 int receive = (command >> 8) & 0xf;
196
197 if (!(ps2work = kmalloc(sizeof(struct ps2work) + max(send, receive), GFP_ATOMIC)))
198 return -1;
199
200 memset(ps2work, 0, sizeof(struct ps2work));
201 ps2work->ps2dev = ps2dev;
202 ps2work->command = command;
203 memcpy(ps2work->param, param, send);
204 INIT_WORK(&ps2work->work, ps2_execute_scheduled_command, ps2work);
205
206 if (!schedule_work(&ps2work->work)) {
207 kfree(ps2work);
208 return -1;
209 }
210
211 return 0;
212}
213
214/*
215 * ps2_init() initializes ps2dev structure
216 */
217
218void ps2_init(struct ps2dev *ps2dev, struct serio *serio)
219{
220 init_MUTEX(&ps2dev->cmd_sem);
221 init_waitqueue_head(&ps2dev->wait);
222 ps2dev->serio = serio;
223}
224
225/*
226 * ps2_handle_ack() is supposed to be used in interrupt handler
227 * to properly process ACK/NAK of a command from a PS/2 device.
228 */
229
230int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
231{
232 switch (data) {
233 case PS2_RET_ACK:
234 ps2dev->nak = 0;
235 break;
236
237 case PS2_RET_NAK:
238 ps2dev->nak = 1;
239 break;
240
241 /*
242 * Workaround for mice which don't ACK the Get ID command.
243 * These are valid mouse IDs that we recognize.
244 */
245 case 0x00:
246 case 0x03:
247 case 0x04:
248 if (ps2dev->flags & PS2_FLAG_WAITID) {
249 ps2dev->nak = 0;
250 break;
251 }
252 /* Fall through */
253 default:
254 return 0;
255 }
256
257
258 if (!ps2dev->nak && ps2dev->cmdcnt)
259 ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
260
261 ps2dev->flags &= ~PS2_FLAG_ACK;
262 wake_up(&ps2dev->wait);
263
264 if (data != PS2_RET_ACK)
265 ps2_handle_response(ps2dev, data);
266
267 return 1;
268}
269
270/*
271 * ps2_handle_response() is supposed to be used in interrupt handler
272 * to properly store device's response to a command and notify process
273 * waiting for completion of the command.
274 */
275
276int ps2_handle_response(struct ps2dev *ps2dev, unsigned char data)
277{
278 if (ps2dev->cmdcnt)
279 ps2dev->cmdbuf[--ps2dev->cmdcnt] = data;
280
281 if (ps2dev->flags & PS2_FLAG_CMD1) {
282 ps2dev->flags &= ~PS2_FLAG_CMD1;
283 if (ps2dev->cmdcnt)
284 wake_up(&ps2dev->wait);
285 }
286
287 if (!ps2dev->cmdcnt) {
288 ps2dev->flags &= ~PS2_FLAG_CMD;
289 wake_up(&ps2dev->wait);
290 }
291
292 return 1;
293}
294
295void ps2_cmd_aborted(struct ps2dev *ps2dev)
296{
297 if (ps2dev->flags & PS2_FLAG_ACK)
298 ps2dev->nak = 1;
299
300 if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
301 wake_up(&ps2dev->wait);
302
303 ps2dev->flags = 0;
304}
305