Commit | Line | Data |
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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 | ||
d43c36dc | 12 | #include <linux/sched.h> |
1da177e4 | 13 | #include <linux/slab.h> |
9edca64b | 14 | #include <linux/smp_lock.h> |
1da177e4 LT |
15 | #include <linux/poll.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/serio.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/major.h> | |
20 | #include <linux/device.h> | |
1da177e4 LT |
21 | #include <linux/miscdevice.h> |
22 | #include <linux/wait.h> | |
c4e32e9f | 23 | #include <linux/mutex.h> |
1da177e4 LT |
24 | |
25 | #define DRIVER_DESC "Raw serio driver" | |
26 | ||
27 | MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); | |
28 | MODULE_DESCRIPTION(DRIVER_DESC); | |
29 | MODULE_LICENSE("GPL"); | |
30 | ||
31 | #define SERIO_RAW_QUEUE_LEN 64 | |
32 | struct serio_raw { | |
33 | unsigned char queue[SERIO_RAW_QUEUE_LEN]; | |
34 | unsigned int tail, head; | |
35 | ||
36 | char name[16]; | |
37 | unsigned int refcnt; | |
38 | struct serio *serio; | |
39 | struct miscdevice dev; | |
40 | wait_queue_head_t wait; | |
41 | struct list_head list; | |
42 | struct list_head node; | |
43 | }; | |
44 | ||
45 | struct serio_raw_list { | |
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 LT |
52 | static LIST_HEAD(serio_raw_list); |
53 | static unsigned int serio_raw_no; | |
54 | ||
55 | /********************************************************************* | |
56 | * Interface with userspace (file operations) * | |
57 | *********************************************************************/ | |
58 | ||
59 | static int serio_raw_fasync(int fd, struct file *file, int on) | |
60 | { | |
61 | struct serio_raw_list *list = file->private_data; | |
1da177e4 | 62 | |
60aa4924 | 63 | return fasync_helper(fd, file, on, &list->fasync); |
1da177e4 LT |
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 | 85 | if (retval) |
77554b4d | 86 | return retval; |
1da177e4 | 87 | |
77554b4d TLSC |
88 | serio_raw = serio_raw_locate(iminor(inode)); |
89 | if (!serio_raw) { | |
1da177e4 LT |
90 | retval = -ENODEV; |
91 | goto out; | |
92 | } | |
93 | ||
94 | if (!serio_raw->serio) { | |
95 | retval = -ENODEV; | |
96 | goto out; | |
97 | } | |
98 | ||
77554b4d TLSC |
99 | list = kzalloc(sizeof(struct serio_raw_list), GFP_KERNEL); |
100 | if (!list) { | |
1da177e4 LT |
101 | retval = -ENOMEM; |
102 | goto out; | |
103 | } | |
104 | ||
1da177e4 LT |
105 | list->serio_raw = serio_raw; |
106 | file->private_data = list; | |
107 | ||
108 | serio_raw->refcnt++; | |
109 | list_add_tail(&list->node, &serio_raw->list); | |
110 | ||
111 | out: | |
c4e32e9f | 112 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
113 | return retval; |
114 | } | |
115 | ||
116 | static int serio_raw_cleanup(struct serio_raw *serio_raw) | |
117 | { | |
118 | if (--serio_raw->refcnt == 0) { | |
119 | misc_deregister(&serio_raw->dev); | |
120 | list_del_init(&serio_raw->node); | |
121 | kfree(serio_raw); | |
122 | ||
123 | return 1; | |
124 | } | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | static int serio_raw_release(struct inode *inode, struct file *file) | |
130 | { | |
131 | struct serio_raw_list *list = file->private_data; | |
132 | struct serio_raw *serio_raw = list->serio_raw; | |
133 | ||
c4e32e9f | 134 | mutex_lock(&serio_raw_mutex); |
1da177e4 | 135 | |
1da177e4 LT |
136 | serio_raw_cleanup(serio_raw); |
137 | ||
c4e32e9f | 138 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
139 | return 0; |
140 | } | |
141 | ||
142 | static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) | |
143 | { | |
144 | unsigned long flags; | |
145 | int empty; | |
146 | ||
147 | spin_lock_irqsave(&serio_raw->serio->lock, flags); | |
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 | ||
155 | spin_unlock_irqrestore(&serio_raw->serio->lock, flags); | |
156 | ||
157 | return !empty; | |
158 | } | |
159 | ||
160 | static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) | |
161 | { | |
162 | struct serio_raw_list *list = file->private_data; | |
163 | struct serio_raw *serio_raw = list->serio_raw; | |
4f179f71 | 164 | char uninitialized_var(c); |
1da177e4 LT |
165 | ssize_t retval = 0; |
166 | ||
167 | if (!serio_raw->serio) | |
168 | return -ENODEV; | |
169 | ||
170 | if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK)) | |
171 | return -EAGAIN; | |
172 | ||
173 | retval = wait_event_interruptible(list->serio_raw->wait, | |
174 | serio_raw->head != serio_raw->tail || !serio_raw->serio); | |
175 | if (retval) | |
176 | return retval; | |
177 | ||
178 | if (!serio_raw->serio) | |
179 | return -ENODEV; | |
180 | ||
181 | while (retval < count && serio_raw_fetch_byte(serio_raw, &c)) { | |
182 | if (put_user(c, buffer++)) | |
183 | return -EFAULT; | |
184 | retval++; | |
185 | } | |
186 | ||
187 | return retval; | |
188 | } | |
189 | ||
190 | static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) | |
191 | { | |
192 | struct serio_raw_list *list = file->private_data; | |
193 | ssize_t written = 0; | |
194 | int retval; | |
195 | unsigned char c; | |
196 | ||
c4e32e9f | 197 | retval = mutex_lock_interruptible(&serio_raw_mutex); |
1da177e4 LT |
198 | if (retval) |
199 | return retval; | |
200 | ||
201 | if (!list->serio_raw->serio) { | |
202 | retval = -ENODEV; | |
203 | goto out; | |
204 | } | |
205 | ||
206 | if (count > 32) | |
207 | count = 32; | |
208 | ||
209 | while (count--) { | |
210 | if (get_user(c, buffer++)) { | |
211 | retval = -EFAULT; | |
212 | goto out; | |
213 | } | |
214 | if (serio_write(list->serio_raw->serio, c)) { | |
215 | retval = -EIO; | |
216 | goto out; | |
217 | } | |
218 | written++; | |
219 | }; | |
220 | ||
221 | out: | |
c4e32e9f | 222 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
223 | return written; |
224 | } | |
225 | ||
226 | static unsigned int serio_raw_poll(struct file *file, poll_table *wait) | |
227 | { | |
228 | struct serio_raw_list *list = file->private_data; | |
229 | ||
230 | poll_wait(file, &list->serio_raw->wait, wait); | |
231 | ||
232 | if (list->serio_raw->head != list->serio_raw->tail) | |
233 | return POLLIN | POLLRDNORM; | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
2b8693c0 | 238 | static const struct file_operations serio_raw_fops = { |
1da177e4 LT |
239 | .owner = THIS_MODULE, |
240 | .open = serio_raw_open, | |
241 | .release = serio_raw_release, | |
242 | .read = serio_raw_read, | |
243 | .write = serio_raw_write, | |
244 | .poll = serio_raw_poll, | |
245 | .fasync = serio_raw_fasync, | |
246 | }; | |
247 | ||
248 | ||
249 | /********************************************************************* | |
250 | * Interface with serio port * | |
251 | *********************************************************************/ | |
252 | ||
253 | static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data, | |
7d12e780 | 254 | unsigned int dfl) |
1da177e4 LT |
255 | { |
256 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
257 | struct serio_raw_list *list; | |
258 | unsigned int head = serio_raw->head; | |
259 | ||
260 | /* we are holding serio->lock here so we are prootected */ | |
261 | serio_raw->queue[head] = data; | |
262 | head = (head + 1) % SERIO_RAW_QUEUE_LEN; | |
263 | if (likely(head != serio_raw->tail)) { | |
264 | serio_raw->head = head; | |
265 | list_for_each_entry(list, &serio_raw->list, node) | |
266 | kill_fasync(&list->fasync, SIGIO, POLL_IN); | |
267 | wake_up_interruptible(&serio_raw->wait); | |
268 | } | |
269 | ||
270 | return IRQ_HANDLED; | |
271 | } | |
272 | ||
273 | static int serio_raw_connect(struct serio *serio, struct serio_driver *drv) | |
274 | { | |
275 | struct serio_raw *serio_raw; | |
276 | int err; | |
277 | ||
b39787a9 | 278 | if (!(serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL))) { |
1da177e4 LT |
279 | printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n"); |
280 | return -ENOMEM; | |
281 | } | |
282 | ||
c4e32e9f | 283 | mutex_lock(&serio_raw_mutex); |
1da177e4 | 284 | |
1da177e4 LT |
285 | snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++); |
286 | serio_raw->refcnt = 1; | |
287 | serio_raw->serio = serio; | |
288 | INIT_LIST_HEAD(&serio_raw->list); | |
289 | init_waitqueue_head(&serio_raw->wait); | |
290 | ||
291 | serio_set_drvdata(serio, serio_raw); | |
292 | ||
293 | err = serio_open(serio, drv); | |
294 | if (err) | |
295 | goto out_free; | |
296 | ||
297 | list_add_tail(&serio_raw->node, &serio_raw_list); | |
298 | ||
299 | serio_raw->dev.minor = PSMOUSE_MINOR; | |
300 | serio_raw->dev.name = serio_raw->name; | |
94fbcded | 301 | serio_raw->dev.parent = &serio->dev; |
1da177e4 LT |
302 | serio_raw->dev.fops = &serio_raw_fops; |
303 | ||
304 | err = misc_register(&serio_raw->dev); | |
305 | if (err) { | |
306 | serio_raw->dev.minor = MISC_DYNAMIC_MINOR; | |
307 | err = misc_register(&serio_raw->dev); | |
308 | } | |
309 | ||
310 | if (err) { | |
311 | printk(KERN_INFO "serio_raw: failed to register raw access device for %s\n", | |
312 | serio->phys); | |
313 | goto out_close; | |
314 | } | |
315 | ||
316 | printk(KERN_INFO "serio_raw: raw access enabled on %s (%s, minor %d)\n", | |
317 | serio->phys, serio_raw->name, serio_raw->dev.minor); | |
318 | goto out; | |
319 | ||
320 | out_close: | |
321 | serio_close(serio); | |
322 | list_del_init(&serio_raw->node); | |
323 | out_free: | |
324 | serio_set_drvdata(serio, NULL); | |
325 | kfree(serio_raw); | |
326 | out: | |
c4e32e9f | 327 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
328 | return err; |
329 | } | |
330 | ||
331 | static int serio_raw_reconnect(struct serio *serio) | |
332 | { | |
333 | struct serio_raw *serio_raw = serio_get_drvdata(serio); | |
334 | struct serio_driver *drv = serio->drv; | |
335 | ||
336 | if (!drv || !serio_raw) { | |
337 | printk(KERN_DEBUG "serio_raw: reconnect request, but serio is disconnected, ignoring...\n"); | |
338 | return -1; | |
339 | } | |
340 | ||
341 | /* | |
342 | * Nothing needs to be done here, we just need this method to | |
343 | * keep the same device. | |
344 | */ | |
345 | return 0; | |
346 | } | |
347 | ||
348 | static void serio_raw_disconnect(struct serio *serio) | |
349 | { | |
350 | struct serio_raw *serio_raw; | |
351 | ||
c4e32e9f | 352 | mutex_lock(&serio_raw_mutex); |
1da177e4 LT |
353 | |
354 | serio_raw = serio_get_drvdata(serio); | |
355 | ||
356 | serio_close(serio); | |
357 | serio_set_drvdata(serio, NULL); | |
358 | ||
359 | serio_raw->serio = NULL; | |
360 | if (!serio_raw_cleanup(serio_raw)) | |
361 | wake_up_interruptible(&serio_raw->wait); | |
362 | ||
c4e32e9f | 363 | mutex_unlock(&serio_raw_mutex); |
1da177e4 LT |
364 | } |
365 | ||
366 | static struct serio_device_id serio_raw_serio_ids[] = { | |
367 | { | |
368 | .type = SERIO_8042, | |
369 | .proto = SERIO_ANY, | |
370 | .id = SERIO_ANY, | |
371 | .extra = SERIO_ANY, | |
372 | }, | |
d19497e2 NV |
373 | { |
374 | .type = SERIO_8042_XL, | |
375 | .proto = SERIO_ANY, | |
376 | .id = SERIO_ANY, | |
377 | .extra = SERIO_ANY, | |
378 | }, | |
1da177e4 LT |
379 | { 0 } |
380 | }; | |
381 | ||
382 | MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); | |
383 | ||
384 | static struct serio_driver serio_raw_drv = { | |
385 | .driver = { | |
386 | .name = "serio_raw", | |
387 | }, | |
388 | .description = DRIVER_DESC, | |
389 | .id_table = serio_raw_serio_ids, | |
390 | .interrupt = serio_raw_interrupt, | |
391 | .connect = serio_raw_connect, | |
392 | .reconnect = serio_raw_reconnect, | |
393 | .disconnect = serio_raw_disconnect, | |
394 | .manual_bind = 1, | |
395 | }; | |
396 | ||
397 | static int __init serio_raw_init(void) | |
398 | { | |
153a9df0 | 399 | return serio_register_driver(&serio_raw_drv); |
1da177e4 LT |
400 | } |
401 | ||
402 | static void __exit serio_raw_exit(void) | |
403 | { | |
404 | serio_unregister_driver(&serio_raw_drv); | |
405 | } | |
406 | ||
407 | module_init(serio_raw_init); | |
408 | module_exit(serio_raw_exit); |