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 | ||
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> | |
19 | #include <linux/devfs_fs_kernel.h> | |
20 | #include <linux/miscdevice.h> | |
21 | #include <linux/wait.h> | |
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 | ||
49 | static DECLARE_MUTEX(serio_raw_sem); | |
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 | ||
84 | retval = down_interruptible(&serio_raw_sem); | |
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 | ||
98 | if (!(list = kmalloc(sizeof(struct serio_raw_list), GFP_KERNEL))) { | |
99 | retval = -ENOMEM; | |
100 | goto out; | |
101 | } | |
102 | ||
103 | memset(list, 0, sizeof(struct serio_raw_list)); | |
104 | list->serio_raw = serio_raw; | |
105 | file->private_data = list; | |
106 | ||
107 | serio_raw->refcnt++; | |
108 | list_add_tail(&list->node, &serio_raw->list); | |
109 | ||
110 | out: | |
111 | up(&serio_raw_sem); | |
112 | return retval; | |
113 | } | |
114 | ||
115 | static int serio_raw_cleanup(struct serio_raw *serio_raw) | |
116 | { | |
117 | if (--serio_raw->refcnt == 0) { | |
118 | misc_deregister(&serio_raw->dev); | |
119 | list_del_init(&serio_raw->node); | |
120 | kfree(serio_raw); | |
121 | ||
122 | return 1; | |
123 | } | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int serio_raw_release(struct inode *inode, struct file *file) | |
129 | { | |
130 | struct serio_raw_list *list = file->private_data; | |
131 | struct serio_raw *serio_raw = list->serio_raw; | |
132 | ||
133 | down(&serio_raw_sem); | |
134 | ||
135 | serio_raw_fasync(-1, file, 0); | |
136 | serio_raw_cleanup(serio_raw); | |
137 | ||
138 | up(&serio_raw_sem); | |
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; | |
164 | char c; | |
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 | ||
197 | retval = down_interruptible(&serio_raw_sem); | |
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: | |
222 | up(&serio_raw_sem); | |
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 | ||
238 | static struct file_operations serio_raw_fops = { | |
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, | |
254 | unsigned int dfl, struct pt_regs *regs) | |
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 | ||
278 | if (!(serio_raw = kmalloc(sizeof(struct serio_raw), GFP_KERNEL))) { | |
279 | printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n"); | |
280 | return -ENOMEM; | |
281 | } | |
282 | ||
283 | down(&serio_raw_sem); | |
284 | ||
285 | memset(serio_raw, 0, sizeof(struct serio_raw)); | |
286 | snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++); | |
287 | serio_raw->refcnt = 1; | |
288 | serio_raw->serio = serio; | |
289 | INIT_LIST_HEAD(&serio_raw->list); | |
290 | init_waitqueue_head(&serio_raw->wait); | |
291 | ||
292 | serio_set_drvdata(serio, serio_raw); | |
293 | ||
294 | err = serio_open(serio, drv); | |
295 | if (err) | |
296 | goto out_free; | |
297 | ||
298 | list_add_tail(&serio_raw->node, &serio_raw_list); | |
299 | ||
300 | serio_raw->dev.minor = PSMOUSE_MINOR; | |
301 | serio_raw->dev.name = serio_raw->name; | |
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: | |
327 | up(&serio_raw_sem); | |
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 | ||
352 | down(&serio_raw_sem); | |
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 | ||
363 | up(&serio_raw_sem); | |
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 | }, | |
373 | { 0 } | |
374 | }; | |
375 | ||
376 | MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); | |
377 | ||
378 | static struct serio_driver serio_raw_drv = { | |
379 | .driver = { | |
380 | .name = "serio_raw", | |
381 | }, | |
382 | .description = DRIVER_DESC, | |
383 | .id_table = serio_raw_serio_ids, | |
384 | .interrupt = serio_raw_interrupt, | |
385 | .connect = serio_raw_connect, | |
386 | .reconnect = serio_raw_reconnect, | |
387 | .disconnect = serio_raw_disconnect, | |
388 | .manual_bind = 1, | |
389 | }; | |
390 | ||
391 | static int __init serio_raw_init(void) | |
392 | { | |
393 | serio_register_driver(&serio_raw_drv); | |
394 | return 0; | |
395 | } | |
396 | ||
397 | static void __exit serio_raw_exit(void) | |
398 | { | |
399 | serio_unregister_driver(&serio_raw_drv); | |
400 | } | |
401 | ||
402 | module_init(serio_raw_init); | |
403 | module_exit(serio_raw_exit); |