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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 | ||
12 | #include <linux/slab.h> | |
13 | #include <linux/poll.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/serio.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/major.h> | |
18 | #include <linux/device.h> | |
1da177e4 LT |
19 | #include <linux/miscdevice.h> |
20 | #include <linux/wait.h> | |
c4e32e9f | 21 | #include <linux/mutex.h> |
1da177e4 LT |
22 | |
23 | #define DRIVER_DESC "Raw serio driver" | |
24 | ||
25 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); | |
26 | MODULE_DESCRIPTION(DRIVER_DESC); | |
27 | MODULE_LICENSE("GPL"); | |
28 | ||
29 | #define SERIO_RAW_QUEUE_LEN 64 | |
30 | struct serio_raw { | |
31 | unsigned char queue[SERIO_RAW_QUEUE_LEN]; | |
32 | unsigned int tail, head; | |
33 | ||
34 | char name[16]; | |
35 | unsigned int refcnt; | |
36 | struct serio *serio; | |
37 | struct miscdevice dev; | |
38 | wait_queue_head_t wait; | |
39 | struct list_head list; | |
40 | struct list_head node; | |
41 | }; | |
42 | ||
43 | struct serio_raw_list { | |
44 | struct fasync_struct *fasync; | |
45 | struct serio_raw *serio_raw; | |
46 | struct list_head node; | |
47 | }; | |
48 | ||
c4e32e9f | 49 | static DEFINE_MUTEX(serio_raw_mutex); |
1da177e4 LT |
50 | static LIST_HEAD(serio_raw_list); |
51 | static unsigned int serio_raw_no; | |
52 | ||
53 | /********************************************************************* | |
54 | * Interface with userspace (file operations) * | |
55 | *********************************************************************/ | |
56 | ||
57 | static int serio_raw_fasync(int fd, struct file *file, int on) | |
58 | { | |
59 | struct serio_raw_list *list = file->private_data; | |
60 | int retval; | |
61 | ||
62 | retval = fasync_helper(fd, file, on, &list->fasync); | |
63 | return retval < 0 ? retval : 0; | |
64 | } | |
65 | ||
66 | static struct serio_raw *serio_raw_locate(int minor) | |
67 | { | |
68 | struct serio_raw *serio_raw; | |
69 | ||
70 | list_for_each_entry(serio_raw, &serio_raw_list, node) { | |
71 | if (serio_raw->dev.minor == minor) | |
72 | return serio_raw; | |
73 | } | |
74 | ||
75 | return NULL; | |
76 | } | |
77 | ||
78 | static int serio_raw_open(struct inode *inode, struct file *file) | |
79 | { | |
80 | struct serio_raw *serio_raw; | |
81 | struct serio_raw_list *list; | |
82 | int retval = 0; | |
83 | ||
c4e32e9f | 84 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
1da177e4 LT |
85 | if (retval) |
86 | return retval; | |
87 | ||
88 | if (!(serio_raw = serio_raw_locate(iminor(inode)))) { | |
89 | retval = -ENODEV; | |
90 | goto out; | |
91 | } | |
92 | ||
93 | if (!serio_raw->serio) { | |
94 | retval = -ENODEV; | |
95 | goto out; | |
96 | } | |
97 | ||
b39787a9 | 98 | if (!(list = kzalloc(sizeof(struct serio_raw_list), GFP_KERNEL))) { |
1da177e4 LT |
99 | retval = -ENOMEM; |
100 | goto out; | |
101 | } | |
102 | ||
1da177e4 LT |
103 | list->serio_raw = serio_raw; |
104 | file->private_data = list; | |
105 | ||
106 | serio_raw->refcnt++; | |
107 | list_add_tail(&list->node, &serio_raw->list); | |
108 | ||
109 | out: | |
c4e32e9f | 110 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
111 | return retval; |
112 | } | |
113 | ||
114 | static int serio_raw_cleanup(struct serio_raw *serio_raw) | |
115 | { | |
116 | if (--serio_raw->refcnt == 0) { | |
117 | misc_deregister(&serio_raw->dev); | |
118 | list_del_init(&serio_raw->node); | |
119 | kfree(serio_raw); | |
120 | ||
121 | return 1; | |
122 | } | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | static int serio_raw_release(struct inode *inode, struct file *file) | |
128 | { | |
129 | struct serio_raw_list *list = file->private_data; | |
130 | struct serio_raw *serio_raw = list->serio_raw; | |
131 | ||
c4e32e9f | 132 | mutex_lock(&serio_raw_mutex); |
1da177e4 LT |
133 | |
134 | serio_raw_fasync(-1, file, 0); | |
135 | serio_raw_cleanup(serio_raw); | |
136 | ||
c4e32e9f | 137 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
138 | return 0; |
139 | } | |
140 | ||
141 | static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) | |
142 | { | |
143 | unsigned long flags; | |
144 | int empty; | |
145 | ||
146 | spin_lock_irqsave(&serio_raw->serio->lock, flags); | |
147 | ||
148 | empty = serio_raw->head == serio_raw->tail; | |
149 | if (!empty) { | |
150 | *c = serio_raw->queue[serio_raw->tail]; | |
151 | serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN; | |
152 | } | |
153 | ||
154 | spin_unlock_irqrestore(&serio_raw->serio->lock, flags); | |
155 | ||
156 | return !empty; | |
157 | } | |
158 | ||
159 | static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) | |
160 | { | |
161 | struct serio_raw_list *list = file->private_data; | |
162 | struct serio_raw *serio_raw = list->serio_raw; | |
163 | char c; | |
164 | ssize_t retval = 0; | |
165 | ||
166 | if (!serio_raw->serio) | |
167 | return -ENODEV; | |
168 | ||
169 | if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK)) | |
170 | return -EAGAIN; | |
171 | ||
172 | retval = wait_event_interruptible(list->serio_raw->wait, | |
173 | serio_raw->head != serio_raw->tail || !serio_raw->serio); | |
174 | if (retval) | |
175 | return retval; | |
176 | ||
177 | if (!serio_raw->serio) | |
178 | return -ENODEV; | |
179 | ||
180 | while (retval < count && serio_raw_fetch_byte(serio_raw, &c)) { | |
181 | if (put_user(c, buffer++)) | |
182 | return -EFAULT; | |
183 | retval++; | |
184 | } | |
185 | ||
186 | return retval; | |
187 | } | |
188 | ||
189 | static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) | |
190 | { | |
191 | struct serio_raw_list *list = file->private_data; | |
192 | ssize_t written = 0; | |
193 | int retval; | |
194 | unsigned char c; | |
195 | ||
c4e32e9f | 196 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
1da177e4 LT |
197 | if (retval) |
198 | return retval; | |
199 | ||
200 | if (!list->serio_raw->serio) { | |
201 | retval = -ENODEV; | |
202 | goto out; | |
203 | } | |
204 | ||
205 | if (count > 32) | |
206 | count = 32; | |
207 | ||
208 | while (count--) { | |
209 | if (get_user(c, buffer++)) { | |
210 | retval = -EFAULT; | |
211 | goto out; | |
212 | } | |
213 | if (serio_write(list->serio_raw->serio, c)) { | |
214 | retval = -EIO; | |
215 | goto out; | |
216 | } | |
217 | written++; | |
218 | }; | |
219 | ||
220 | out: | |
c4e32e9f | 221 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
222 | return written; |
223 | } | |
224 | ||
225 | static unsigned int serio_raw_poll(struct file *file, poll_table *wait) | |
226 | { | |
227 | struct serio_raw_list *list = file->private_data; | |
228 | ||
229 | poll_wait(file, &list->serio_raw->wait, wait); | |
230 | ||
231 | if (list->serio_raw->head != list->serio_raw->tail) | |
232 | return POLLIN | POLLRDNORM; | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
237 | static struct file_operations serio_raw_fops = { | |
238 | .owner = THIS_MODULE, | |
239 | .open = serio_raw_open, | |
240 | .release = serio_raw_release, | |
241 | .read = serio_raw_read, | |
242 | .write = serio_raw_write, | |
243 | .poll = serio_raw_poll, | |
244 | .fasync = serio_raw_fasync, | |
245 | }; | |
246 | ||
247 | ||
248 | /********************************************************************* | |
249 | * Interface with serio port * | |
250 | *********************************************************************/ | |
251 | ||
252 | static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data, | |
7d12e780 | 253 | unsigned int dfl) |
1da177e4 LT |
254 | { |
255 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
256 | struct serio_raw_list *list; | |
257 | unsigned int head = serio_raw->head; | |
258 | ||
259 | /* we are holding serio->lock here so we are prootected */ | |
260 | serio_raw->queue[head] = data; | |
261 | head = (head + 1) % SERIO_RAW_QUEUE_LEN; | |
262 | if (likely(head != serio_raw->tail)) { | |
263 | serio_raw->head = head; | |
264 | list_for_each_entry(list, &serio_raw->list, node) | |
265 | kill_fasync(&list->fasync, SIGIO, POLL_IN); | |
266 | wake_up_interruptible(&serio_raw->wait); | |
267 | } | |
268 | ||
269 | return IRQ_HANDLED; | |
270 | } | |
271 | ||
272 | static int serio_raw_connect(struct serio *serio, struct serio_driver *drv) | |
273 | { | |
274 | struct serio_raw *serio_raw; | |
275 | int err; | |
276 | ||
b39787a9 | 277 | if (!(serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL))) { |
1da177e4 LT |
278 | printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n"); |
279 | return -ENOMEM; | |
280 | } | |
281 | ||
c4e32e9f | 282 | mutex_lock(&serio_raw_mutex); |
1da177e4 | 283 | |
1da177e4 LT |
284 | snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++); |
285 | serio_raw->refcnt = 1; | |
286 | serio_raw->serio = serio; | |
287 | INIT_LIST_HEAD(&serio_raw->list); | |
288 | init_waitqueue_head(&serio_raw->wait); | |
289 | ||
290 | serio_set_drvdata(serio, serio_raw); | |
291 | ||
292 | err = serio_open(serio, drv); | |
293 | if (err) | |
294 | goto out_free; | |
295 | ||
296 | list_add_tail(&serio_raw->node, &serio_raw_list); | |
297 | ||
298 | serio_raw->dev.minor = PSMOUSE_MINOR; | |
299 | serio_raw->dev.name = serio_raw->name; | |
dc1e97b5 | 300 | serio_raw->dev.dev = &serio->dev; |
1da177e4 LT |
301 | serio_raw->dev.fops = &serio_raw_fops; |
302 | ||
303 | err = misc_register(&serio_raw->dev); | |
304 | if (err) { | |
305 | serio_raw->dev.minor = MISC_DYNAMIC_MINOR; | |
306 | err = misc_register(&serio_raw->dev); | |
307 | } | |
308 | ||
309 | if (err) { | |
310 | printk(KERN_INFO "serio_raw: failed to register raw access device for %s\n", | |
311 | serio->phys); | |
312 | goto out_close; | |
313 | } | |
314 | ||
315 | printk(KERN_INFO "serio_raw: raw access enabled on %s (%s, minor %d)\n", | |
316 | serio->phys, serio_raw->name, serio_raw->dev.minor); | |
317 | goto out; | |
318 | ||
319 | out_close: | |
320 | serio_close(serio); | |
321 | list_del_init(&serio_raw->node); | |
322 | out_free: | |
323 | serio_set_drvdata(serio, NULL); | |
324 | kfree(serio_raw); | |
325 | out: | |
c4e32e9f | 326 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
327 | return err; |
328 | } | |
329 | ||
330 | static int serio_raw_reconnect(struct serio *serio) | |
331 | { | |
332 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
333 | struct serio_driver *drv = serio->drv; | |
334 | ||
335 | if (!drv || !serio_raw) { | |
336 | printk(KERN_DEBUG "serio_raw: reconnect request, but serio is disconnected, ignoring...\n"); | |
337 | return -1; | |
338 | } | |
339 | ||
340 | /* | |
341 | * Nothing needs to be done here, we just need this method to | |
342 | * keep the same device. | |
343 | */ | |
344 | return 0; | |
345 | } | |
346 | ||
347 | static void serio_raw_disconnect(struct serio *serio) | |
348 | { | |
349 | struct serio_raw *serio_raw; | |
350 | ||
c4e32e9f | 351 | mutex_lock(&serio_raw_mutex); |
1da177e4 LT |
352 | |
353 | serio_raw = serio_get_drvdata(serio); | |
354 | ||
355 | serio_close(serio); | |
356 | serio_set_drvdata(serio, NULL); | |
357 | ||
358 | serio_raw->serio = NULL; | |
359 | if (!serio_raw_cleanup(serio_raw)) | |
360 | wake_up_interruptible(&serio_raw->wait); | |
361 | ||
c4e32e9f | 362 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
363 | } |
364 | ||
365 | static struct serio_device_id serio_raw_serio_ids[] = { | |
366 | { | |
367 | .type = SERIO_8042, | |
368 | .proto = SERIO_ANY, | |
369 | .id = SERIO_ANY, | |
370 | .extra = SERIO_ANY, | |
371 | }, | |
372 | { 0 } | |
373 | }; | |
374 | ||
375 | MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); | |
376 | ||
377 | static struct serio_driver serio_raw_drv = { | |
378 | .driver = { | |
379 | .name = "serio_raw", | |
380 | }, | |
381 | .description = DRIVER_DESC, | |
382 | .id_table = serio_raw_serio_ids, | |
383 | .interrupt = serio_raw_interrupt, | |
384 | .connect = serio_raw_connect, | |
385 | .reconnect = serio_raw_reconnect, | |
386 | .disconnect = serio_raw_disconnect, | |
387 | .manual_bind = 1, | |
388 | }; | |
389 | ||
390 | static int __init serio_raw_init(void) | |
391 | { | |
392 | serio_register_driver(&serio_raw_drv); | |
393 | return 0; | |
394 | } | |
395 | ||
396 | static void __exit serio_raw_exit(void) | |
397 | { | |
398 | serio_unregister_driver(&serio_raw_drv); | |
399 | } | |
400 | ||
401 | module_init(serio_raw_init); | |
402 | module_exit(serio_raw_exit); |