Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Raw serio device providing access to a raw byte stream from underlying | |
3 | * serio port. Closely emulates behavior of pre-2.6 /dev/psaux device | |
4 | * | |
5 | * Copyright (c) 2004 Dmitry Torokhov | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published by | |
9 | * the Free Software Foundation. | |
10 | */ | |
11 | ||
ba538cd2 | 12 | #include <linux/kref.h> |
d43c36dc | 13 | #include <linux/sched.h> |
1da177e4 LT |
14 | #include <linux/slab.h> |
15 | #include <linux/poll.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/serio.h> | |
1da177e4 LT |
18 | #include <linux/major.h> |
19 | #include <linux/device.h> | |
1da177e4 LT |
20 | #include <linux/miscdevice.h> |
21 | #include <linux/wait.h> | |
c4e32e9f | 22 | #include <linux/mutex.h> |
1da177e4 LT |
23 | |
24 | #define DRIVER_DESC "Raw serio driver" | |
25 | ||
26 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); | |
27 | MODULE_DESCRIPTION(DRIVER_DESC); | |
28 | MODULE_LICENSE("GPL"); | |
29 | ||
30 | #define SERIO_RAW_QUEUE_LEN 64 | |
31 | struct serio_raw { | |
32 | unsigned char queue[SERIO_RAW_QUEUE_LEN]; | |
33 | unsigned int tail, head; | |
34 | ||
35 | char name[16]; | |
ba538cd2 | 36 | struct kref kref; |
1da177e4 LT |
37 | struct serio *serio; |
38 | struct miscdevice dev; | |
39 | wait_queue_head_t wait; | |
7c5bbb2e | 40 | struct list_head client_list; |
1da177e4 | 41 | struct list_head node; |
85f5b35d | 42 | bool dead; |
1da177e4 LT |
43 | }; |
44 | ||
7c5bbb2e | 45 | struct serio_raw_client { |
1da177e4 LT |
46 | struct fasync_struct *fasync; |
47 | struct serio_raw *serio_raw; | |
48 | struct list_head node; | |
49 | }; | |
50 | ||
c4e32e9f | 51 | static DEFINE_MUTEX(serio_raw_mutex); |
1da177e4 | 52 | static LIST_HEAD(serio_raw_list); |
1da177e4 LT |
53 | |
54 | /********************************************************************* | |
55 | * Interface with userspace (file operations) * | |
56 | *********************************************************************/ | |
57 | ||
58 | static int serio_raw_fasync(int fd, struct file *file, int on) | |
59 | { | |
7c5bbb2e | 60 | struct serio_raw_client *client = file->private_data; |
1da177e4 | 61 | |
7c5bbb2e | 62 | return fasync_helper(fd, file, on, &client->fasync); |
1da177e4 LT |
63 | } |
64 | ||
65 | static struct serio_raw *serio_raw_locate(int minor) | |
66 | { | |
67 | struct serio_raw *serio_raw; | |
68 | ||
69 | list_for_each_entry(serio_raw, &serio_raw_list, node) { | |
70 | if (serio_raw->dev.minor == minor) | |
71 | return serio_raw; | |
72 | } | |
73 | ||
74 | return NULL; | |
75 | } | |
76 | ||
77 | static int serio_raw_open(struct inode *inode, struct file *file) | |
78 | { | |
79 | struct serio_raw *serio_raw; | |
7c5bbb2e DT |
80 | struct serio_raw_client *client; |
81 | int retval; | |
1da177e4 | 82 | |
c4e32e9f | 83 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
1da177e4 | 84 | if (retval) |
77554b4d | 85 | return retval; |
1da177e4 | 86 | |
77554b4d TLSC |
87 | serio_raw = serio_raw_locate(iminor(inode)); |
88 | if (!serio_raw) { | |
1da177e4 LT |
89 | retval = -ENODEV; |
90 | goto out; | |
91 | } | |
92 | ||
85f5b35d | 93 | if (serio_raw->dead) { |
1da177e4 LT |
94 | retval = -ENODEV; |
95 | goto out; | |
96 | } | |
97 | ||
7c5bbb2e DT |
98 | client = kzalloc(sizeof(struct serio_raw_client), GFP_KERNEL); |
99 | if (!client) { | |
1da177e4 LT |
100 | retval = -ENOMEM; |
101 | goto out; | |
102 | } | |
103 | ||
7c5bbb2e DT |
104 | client->serio_raw = serio_raw; |
105 | file->private_data = client; | |
1da177e4 | 106 | |
ba538cd2 | 107 | kref_get(&serio_raw->kref); |
843e784a DT |
108 | |
109 | serio_pause_rx(serio_raw->serio); | |
7c5bbb2e | 110 | list_add_tail(&client->node, &serio_raw->client_list); |
843e784a | 111 | serio_continue_rx(serio_raw->serio); |
1da177e4 LT |
112 | |
113 | out: | |
c4e32e9f | 114 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
115 | return retval; |
116 | } | |
117 | ||
550eca7c | 118 | static void serio_raw_free(struct kref *kref) |
1da177e4 | 119 | { |
ba538cd2 DT |
120 | struct serio_raw *serio_raw = |
121 | container_of(kref, struct serio_raw, kref); | |
1da177e4 | 122 | |
85f5b35d | 123 | put_device(&serio_raw->serio->dev); |
ba538cd2 | 124 | kfree(serio_raw); |
1da177e4 LT |
125 | } |
126 | ||
127 | static int serio_raw_release(struct inode *inode, struct file *file) | |
128 | { | |
7c5bbb2e DT |
129 | struct serio_raw_client *client = file->private_data; |
130 | struct serio_raw *serio_raw = client->serio_raw; | |
1da177e4 | 131 | |
550eca7c DT |
132 | serio_pause_rx(serio_raw->serio); |
133 | list_del(&client->node); | |
134 | serio_continue_rx(serio_raw->serio); | |
1da177e4 | 135 | |
550eca7c DT |
136 | kfree(client); |
137 | ||
138 | kref_put(&serio_raw->kref, serio_raw_free); | |
1da177e4 | 139 | |
1da177e4 LT |
140 | return 0; |
141 | } | |
142 | ||
8c31eb01 | 143 | static bool serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) |
1da177e4 | 144 | { |
8c31eb01 | 145 | bool empty; |
1da177e4 | 146 | |
843e784a | 147 | serio_pause_rx(serio_raw->serio); |
1da177e4 LT |
148 | |
149 | empty = serio_raw->head == serio_raw->tail; | |
150 | if (!empty) { | |
151 | *c = serio_raw->queue[serio_raw->tail]; | |
152 | serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN; | |
153 | } | |
154 | ||
843e784a | 155 | serio_continue_rx(serio_raw->serio); |
1da177e4 LT |
156 | |
157 | return !empty; | |
158 | } | |
159 | ||
15a564d8 DT |
160 | static ssize_t serio_raw_read(struct file *file, char __user *buffer, |
161 | size_t count, loff_t *ppos) | |
1da177e4 | 162 | { |
7c5bbb2e DT |
163 | struct serio_raw_client *client = file->private_data; |
164 | struct serio_raw *serio_raw = client->serio_raw; | |
4f179f71 | 165 | char uninitialized_var(c); |
7a0a27d2 | 166 | ssize_t read = 0; |
46f49b7a | 167 | int error; |
1da177e4 | 168 | |
46f49b7a | 169 | for (;;) { |
486c8aba DT |
170 | if (serio_raw->dead) |
171 | return -ENODEV; | |
1da177e4 | 172 | |
486c8aba DT |
173 | if (serio_raw->head == serio_raw->tail && |
174 | (file->f_flags & O_NONBLOCK)) | |
175 | return -EAGAIN; | |
1da177e4 | 176 | |
486c8aba DT |
177 | if (count == 0) |
178 | break; | |
1da177e4 | 179 | |
486c8aba | 180 | while (read < count && serio_raw_fetch_byte(serio_raw, &c)) { |
46f49b7a DT |
181 | if (put_user(c, buffer++)) |
182 | return -EFAULT; | |
486c8aba DT |
183 | read++; |
184 | } | |
1da177e4 | 185 | |
486c8aba | 186 | if (read) |
7a0a27d2 | 187 | break; |
1da177e4 | 188 | |
46f49b7a | 189 | if (!(file->f_flags & O_NONBLOCK)) { |
486c8aba DT |
190 | error = wait_event_interruptible(serio_raw->wait, |
191 | serio_raw->head != serio_raw->tail || | |
192 | serio_raw->dead); | |
46f49b7a DT |
193 | if (error) |
194 | return error; | |
195 | } | |
196 | } | |
486c8aba | 197 | |
46f49b7a | 198 | return read; |
1da177e4 LT |
199 | } |
200 | ||
15a564d8 DT |
201 | static ssize_t serio_raw_write(struct file *file, const char __user *buffer, |
202 | size_t count, loff_t *ppos) | |
1da177e4 | 203 | { |
7c5bbb2e DT |
204 | struct serio_raw_client *client = file->private_data; |
205 | struct serio_raw *serio_raw = client->serio_raw; | |
46f49b7a | 206 | int retval = 0; |
1da177e4 LT |
207 | unsigned char c; |
208 | ||
c4e32e9f | 209 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
1da177e4 LT |
210 | if (retval) |
211 | return retval; | |
212 | ||
85f5b35d | 213 | if (serio_raw->dead) { |
1da177e4 LT |
214 | retval = -ENODEV; |
215 | goto out; | |
216 | } | |
217 | ||
218 | if (count > 32) | |
219 | count = 32; | |
220 | ||
221 | while (count--) { | |
222 | if (get_user(c, buffer++)) { | |
223 | retval = -EFAULT; | |
224 | goto out; | |
225 | } | |
46f49b7a | 226 | |
7c5bbb2e | 227 | if (serio_write(serio_raw->serio, c)) { |
46f49b7a DT |
228 | /* Either signal error or partial write */ |
229 | if (retval == 0) | |
230 | retval = -EIO; | |
1da177e4 LT |
231 | goto out; |
232 | } | |
46f49b7a DT |
233 | |
234 | retval++; | |
d89c9bcb | 235 | } |
1da177e4 LT |
236 | |
237 | out: | |
c4e32e9f | 238 | mutex_unlock(&serio_raw_mutex); |
46f49b7a | 239 | return retval; |
1da177e4 LT |
240 | } |
241 | ||
afc9a42b | 242 | static __poll_t serio_raw_poll(struct file *file, poll_table *wait) |
1da177e4 | 243 | { |
7c5bbb2e DT |
244 | struct serio_raw_client *client = file->private_data; |
245 | struct serio_raw *serio_raw = client->serio_raw; | |
afc9a42b | 246 | __poll_t mask; |
1da177e4 | 247 | |
7c5bbb2e | 248 | poll_wait(file, &serio_raw->wait, wait); |
1da177e4 | 249 | |
a9a08845 | 250 | mask = serio_raw->dead ? EPOLLHUP | EPOLLERR : EPOLLOUT | EPOLLWRNORM; |
7c5bbb2e | 251 | if (serio_raw->head != serio_raw->tail) |
a9a08845 | 252 | mask |= EPOLLIN | EPOLLRDNORM; |
1da177e4 | 253 | |
0c62fbf6 | 254 | return mask; |
1da177e4 LT |
255 | } |
256 | ||
2b8693c0 | 257 | static const struct file_operations serio_raw_fops = { |
7c5bbb2e DT |
258 | .owner = THIS_MODULE, |
259 | .open = serio_raw_open, | |
260 | .release = serio_raw_release, | |
261 | .read = serio_raw_read, | |
262 | .write = serio_raw_write, | |
263 | .poll = serio_raw_poll, | |
264 | .fasync = serio_raw_fasync, | |
265 | .llseek = noop_llseek, | |
1da177e4 LT |
266 | }; |
267 | ||
268 | ||
269 | /********************************************************************* | |
15a564d8 | 270 | * Interface with serio port * |
1da177e4 LT |
271 | *********************************************************************/ |
272 | ||
273 | static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data, | |
7d12e780 | 274 | unsigned int dfl) |
1da177e4 LT |
275 | { |
276 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
7c5bbb2e | 277 | struct serio_raw_client *client; |
1da177e4 LT |
278 | unsigned int head = serio_raw->head; |
279 | ||
7c5bbb2e | 280 | /* we are holding serio->lock here so we are protected */ |
1da177e4 LT |
281 | serio_raw->queue[head] = data; |
282 | head = (head + 1) % SERIO_RAW_QUEUE_LEN; | |
283 | if (likely(head != serio_raw->tail)) { | |
284 | serio_raw->head = head; | |
7c5bbb2e DT |
285 | list_for_each_entry(client, &serio_raw->client_list, node) |
286 | kill_fasync(&client->fasync, SIGIO, POLL_IN); | |
1da177e4 LT |
287 | wake_up_interruptible(&serio_raw->wait); |
288 | } | |
289 | ||
290 | return IRQ_HANDLED; | |
291 | } | |
292 | ||
293 | static int serio_raw_connect(struct serio *serio, struct serio_driver *drv) | |
294 | { | |
939ffb17 | 295 | static atomic_t serio_raw_no = ATOMIC_INIT(-1); |
1da177e4 LT |
296 | struct serio_raw *serio_raw; |
297 | int err; | |
298 | ||
15a564d8 DT |
299 | serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL); |
300 | if (!serio_raw) { | |
8d928477 | 301 | dev_dbg(&serio->dev, "can't allocate memory for a device\n"); |
1da177e4 LT |
302 | return -ENOMEM; |
303 | } | |
304 | ||
15a564d8 | 305 | snprintf(serio_raw->name, sizeof(serio_raw->name), |
939ffb17 | 306 | "serio_raw%ld", (long)atomic_inc_return(&serio_raw_no)); |
ba538cd2 | 307 | kref_init(&serio_raw->kref); |
7c5bbb2e | 308 | INIT_LIST_HEAD(&serio_raw->client_list); |
1da177e4 LT |
309 | init_waitqueue_head(&serio_raw->wait); |
310 | ||
85f5b35d DT |
311 | serio_raw->serio = serio; |
312 | get_device(&serio->dev); | |
313 | ||
1da177e4 LT |
314 | serio_set_drvdata(serio, serio_raw); |
315 | ||
316 | err = serio_open(serio, drv); | |
317 | if (err) | |
550eca7c DT |
318 | goto err_free; |
319 | ||
320 | err = mutex_lock_killable(&serio_raw_mutex); | |
321 | if (err) | |
322 | goto err_close; | |
1da177e4 LT |
323 | |
324 | list_add_tail(&serio_raw->node, &serio_raw_list); | |
550eca7c | 325 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
326 | |
327 | serio_raw->dev.minor = PSMOUSE_MINOR; | |
328 | serio_raw->dev.name = serio_raw->name; | |
94fbcded | 329 | serio_raw->dev.parent = &serio->dev; |
1da177e4 LT |
330 | serio_raw->dev.fops = &serio_raw_fops; |
331 | ||
332 | err = misc_register(&serio_raw->dev); | |
333 | if (err) { | |
334 | serio_raw->dev.minor = MISC_DYNAMIC_MINOR; | |
335 | err = misc_register(&serio_raw->dev); | |
336 | } | |
337 | ||
338 | if (err) { | |
8d928477 DT |
339 | dev_err(&serio->dev, |
340 | "failed to register raw access device for %s\n", | |
1da177e4 | 341 | serio->phys); |
550eca7c | 342 | goto err_unlink; |
1da177e4 LT |
343 | } |
344 | ||
8d928477 DT |
345 | dev_info(&serio->dev, "raw access enabled on %s (%s, minor %d)\n", |
346 | serio->phys, serio_raw->name, serio_raw->dev.minor); | |
550eca7c | 347 | return 0; |
1da177e4 | 348 | |
550eca7c | 349 | err_unlink: |
1da177e4 | 350 | list_del_init(&serio_raw->node); |
550eca7c DT |
351 | err_close: |
352 | serio_close(serio); | |
353 | err_free: | |
1da177e4 | 354 | serio_set_drvdata(serio, NULL); |
550eca7c | 355 | kref_put(&serio_raw->kref, serio_raw_free); |
1da177e4 LT |
356 | return err; |
357 | } | |
358 | ||
359 | static int serio_raw_reconnect(struct serio *serio) | |
360 | { | |
361 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
362 | struct serio_driver *drv = serio->drv; | |
363 | ||
364 | if (!drv || !serio_raw) { | |
8d928477 DT |
365 | dev_dbg(&serio->dev, |
366 | "reconnect request, but serio is disconnected, ignoring...\n"); | |
1da177e4 LT |
367 | return -1; |
368 | } | |
369 | ||
370 | /* | |
371 | * Nothing needs to be done here, we just need this method to | |
372 | * keep the same device. | |
373 | */ | |
374 | return 0; | |
375 | } | |
376 | ||
8c1c10d5 DT |
377 | /* |
378 | * Wake up users waiting for IO so they can disconnect from | |
379 | * dead device. | |
380 | */ | |
381 | static void serio_raw_hangup(struct serio_raw *serio_raw) | |
382 | { | |
383 | struct serio_raw_client *client; | |
384 | ||
385 | serio_pause_rx(serio_raw->serio); | |
386 | list_for_each_entry(client, &serio_raw->client_list, node) | |
387 | kill_fasync(&client->fasync, SIGIO, POLL_HUP); | |
388 | serio_continue_rx(serio_raw->serio); | |
389 | ||
390 | wake_up_interruptible(&serio_raw->wait); | |
391 | } | |
392 | ||
393 | ||
1da177e4 LT |
394 | static void serio_raw_disconnect(struct serio *serio) |
395 | { | |
8c1c10d5 | 396 | struct serio_raw *serio_raw = serio_get_drvdata(serio); |
1da177e4 | 397 | |
550eca7c | 398 | misc_deregister(&serio_raw->dev); |
1da177e4 | 399 | |
550eca7c | 400 | mutex_lock(&serio_raw_mutex); |
85f5b35d | 401 | serio_raw->dead = true; |
550eca7c DT |
402 | list_del_init(&serio_raw->node); |
403 | mutex_unlock(&serio_raw_mutex); | |
404 | ||
8c1c10d5 | 405 | serio_raw_hangup(serio_raw); |
1da177e4 | 406 | |
550eca7c DT |
407 | serio_close(serio); |
408 | kref_put(&serio_raw->kref, serio_raw_free); | |
8c1c10d5 DT |
409 | |
410 | serio_set_drvdata(serio, NULL); | |
1da177e4 LT |
411 | } |
412 | ||
0aea22b3 | 413 | static const struct serio_device_id serio_raw_serio_ids[] = { |
1da177e4 LT |
414 | { |
415 | .type = SERIO_8042, | |
416 | .proto = SERIO_ANY, | |
417 | .id = SERIO_ANY, | |
418 | .extra = SERIO_ANY, | |
419 | }, | |
d19497e2 NV |
420 | { |
421 | .type = SERIO_8042_XL, | |
422 | .proto = SERIO_ANY, | |
423 | .id = SERIO_ANY, | |
424 | .extra = SERIO_ANY, | |
425 | }, | |
1da177e4 LT |
426 | { 0 } |
427 | }; | |
428 | ||
429 | MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); | |
430 | ||
431 | static struct serio_driver serio_raw_drv = { | |
432 | .driver = { | |
433 | .name = "serio_raw", | |
434 | }, | |
435 | .description = DRIVER_DESC, | |
436 | .id_table = serio_raw_serio_ids, | |
437 | .interrupt = serio_raw_interrupt, | |
438 | .connect = serio_raw_connect, | |
439 | .reconnect = serio_raw_reconnect, | |
440 | .disconnect = serio_raw_disconnect, | |
8c31eb01 | 441 | .manual_bind = true, |
1da177e4 LT |
442 | }; |
443 | ||
65ac9f7a | 444 | module_serio_driver(serio_raw_drv); |