Commit | Line | Data |
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86166b7b JK |
1 | /* |
2 | * HID raw devices, giving access to raw HID events. | |
3 | * | |
4 | * In comparison to hiddev, this device does not process the | |
5 | * hid events at all (no parsing, no lookups). This lets applications | |
6 | * to work on raw hid events as they want to, and avoids a need to | |
7 | * use a transport-specific userspace libhid/libusb libraries. | |
8 | * | |
9 | * Copyright (c) 2007 Jiri Kosina | |
10 | */ | |
11 | ||
12 | /* | |
13 | * This program is free software; you can redistribute it and/or modify it | |
14 | * under the terms and conditions of the GNU General Public License, | |
15 | * version 2, as published by the Free Software Foundation. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along with | |
18 | * this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
20 | */ | |
21 | ||
22 | #include <linux/fs.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/kernel.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/cdev.h> | |
28 | #include <linux/poll.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/major.h> | |
31 | #include <linux/hid.h> | |
32 | #include <linux/mutex.h> | |
33 | ||
34 | #include <linux/hidraw.h> | |
35 | ||
36 | static int hidraw_major; | |
37 | static struct cdev hidraw_cdev; | |
38 | static struct class *hidraw_class; | |
39 | static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; | |
40 | static DEFINE_SPINLOCK(minors_lock); | |
41 | ||
42 | static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) | |
43 | { | |
44 | struct hidraw_list *list = file->private_data; | |
45 | int ret = 0, len; | |
46 | char *report; | |
47 | DECLARE_WAITQUEUE(wait, current); | |
48 | ||
49 | while (ret == 0) { | |
50 | ||
51 | mutex_lock(&list->read_mutex); | |
52 | ||
53 | if (list->head == list->tail) { | |
54 | add_wait_queue(&list->hidraw->wait, &wait); | |
55 | set_current_state(TASK_INTERRUPTIBLE); | |
56 | ||
57 | while (list->head == list->tail) { | |
58 | if (file->f_flags & O_NONBLOCK) { | |
59 | ret = -EAGAIN; | |
60 | break; | |
61 | } | |
62 | if (signal_pending(current)) { | |
63 | ret = -ERESTARTSYS; | |
64 | break; | |
65 | } | |
66 | if (!list->hidraw->exist) { | |
67 | ret = -EIO; | |
68 | break; | |
69 | } | |
70 | ||
71 | /* allow O_NONBLOCK to work well from other threads */ | |
72 | mutex_unlock(&list->read_mutex); | |
73 | schedule(); | |
74 | mutex_lock(&list->read_mutex); | |
75 | set_current_state(TASK_INTERRUPTIBLE); | |
76 | } | |
77 | ||
78 | set_current_state(TASK_RUNNING); | |
79 | remove_wait_queue(&list->hidraw->wait, &wait); | |
80 | } | |
81 | ||
82 | if (ret) | |
83 | goto out; | |
84 | ||
85 | report = list->buffer[list->tail].value; | |
86 | len = list->buffer[list->tail].len > count ? | |
87 | count : list->buffer[list->tail].len; | |
88 | ||
89 | if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { | |
90 | ret = -EFAULT; | |
91 | goto out; | |
92 | } | |
93 | ret += len; | |
94 | ||
95 | kfree(list->buffer[list->tail].value); | |
96 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
97 | } | |
98 | out: | |
99 | mutex_unlock(&list->read_mutex); | |
100 | return ret; | |
101 | } | |
102 | ||
103 | /* the first byte is expected to be a report number */ | |
104 | static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) | |
105 | { | |
106 | unsigned int minor = iminor(file->f_path.dentry->d_inode); | |
107 | struct hid_device *dev = hidraw_table[minor]->hid; | |
108 | __u8 *buf; | |
109 | int ret = 0; | |
110 | ||
111 | if (!dev->hid_output_raw_report) | |
112 | return -ENODEV; | |
113 | ||
114 | if (count > HID_MIN_BUFFER_SIZE) { | |
115 | printk(KERN_WARNING "hidraw: pid %d passed too large report\n", | |
ba25f9dc | 116 | task_pid_nr(current)); |
86166b7b JK |
117 | return -EINVAL; |
118 | } | |
119 | ||
120 | if (count < 2) { | |
121 | printk(KERN_WARNING "hidraw: pid %d passed too short report\n", | |
ba25f9dc | 122 | task_pid_nr(current)); |
86166b7b JK |
123 | return -EINVAL; |
124 | } | |
125 | ||
126 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); | |
127 | if (!buf) | |
128 | return -ENOMEM; | |
129 | ||
130 | if (copy_from_user(buf, buffer, count)) { | |
131 | ret = -EFAULT; | |
132 | goto out; | |
133 | } | |
134 | ||
135 | ret = dev->hid_output_raw_report(dev, buf, count); | |
136 | out: | |
137 | kfree(buf); | |
138 | return ret; | |
139 | } | |
140 | ||
141 | static unsigned int hidraw_poll(struct file *file, poll_table *wait) | |
142 | { | |
143 | struct hidraw_list *list = file->private_data; | |
144 | ||
145 | poll_wait(file, &list->hidraw->wait, wait); | |
146 | if (list->head != list->tail) | |
147 | return POLLIN | POLLRDNORM; | |
148 | if (!list->hidraw->exist) | |
149 | return POLLERR | POLLHUP; | |
150 | return 0; | |
151 | } | |
152 | ||
153 | static int hidraw_open(struct inode *inode, struct file *file) | |
154 | { | |
155 | unsigned int minor = iminor(inode); | |
156 | struct hidraw *dev; | |
157 | struct hidraw_list *list; | |
158 | int err = 0; | |
159 | ||
160 | if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { | |
161 | err = -ENOMEM; | |
162 | goto out; | |
163 | } | |
164 | ||
165 | spin_lock(&minors_lock); | |
166 | if (!hidraw_table[minor]) { | |
167 | printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", | |
168 | minor); | |
169 | kfree(list); | |
170 | err = -ENODEV; | |
171 | goto out_unlock; | |
172 | } | |
173 | ||
174 | list->hidraw = hidraw_table[minor]; | |
175 | mutex_init(&list->read_mutex); | |
176 | list_add_tail(&list->node, &hidraw_table[minor]->list); | |
177 | file->private_data = list; | |
178 | ||
179 | dev = hidraw_table[minor]; | |
180 | if (!dev->open++) | |
181 | dev->hid->hid_open(dev->hid); | |
182 | ||
183 | out_unlock: | |
184 | spin_unlock(&minors_lock); | |
185 | out: | |
186 | return err; | |
187 | ||
188 | } | |
189 | ||
190 | static int hidraw_release(struct inode * inode, struct file * file) | |
191 | { | |
192 | unsigned int minor = iminor(inode); | |
193 | struct hidraw *dev; | |
194 | struct hidraw_list *list = file->private_data; | |
195 | ||
196 | if (!hidraw_table[minor]) { | |
197 | printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", | |
198 | minor); | |
199 | return -ENODEV; | |
200 | } | |
201 | ||
202 | list_del(&list->node); | |
203 | dev = hidraw_table[minor]; | |
204 | if (!dev->open--) { | |
205 | if (list->hidraw->exist) | |
206 | dev->hid->hid_close(dev->hid); | |
207 | else | |
208 | kfree(list->hidraw); | |
209 | } | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | static int hidraw_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
215 | { | |
216 | unsigned int minor = iminor(inode); | |
217 | struct hidraw *dev = hidraw_table[minor]; | |
218 | void __user *user_arg = (void __user*) arg; | |
219 | ||
220 | switch (cmd) { | |
221 | case HIDIOCGRDESCSIZE: | |
222 | if (put_user(dev->hid->rsize, (int __user *)arg)) | |
223 | return -EFAULT; | |
224 | return 0; | |
225 | ||
226 | case HIDIOCGRDESC: | |
227 | { | |
228 | __u32 len; | |
229 | ||
230 | if (get_user(len, (int __user *)arg)) | |
231 | return -EFAULT; | |
57d292bd JK |
232 | |
233 | if (len > HID_MAX_DESCRIPTOR_SIZE - 1) | |
234 | return -EINVAL; | |
235 | ||
236 | if (copy_to_user(user_arg + offsetof( | |
237 | struct hidraw_report_descriptor, | |
238 | value[0]), | |
239 | dev->hid->rdesc, | |
240 | min(dev->hid->rsize, len))) | |
86166b7b JK |
241 | return -EFAULT; |
242 | return 0; | |
243 | } | |
244 | case HIDIOCGRAWINFO: | |
245 | { | |
246 | struct hidraw_devinfo dinfo; | |
247 | ||
248 | dinfo.bustype = dev->hid->bus; | |
249 | dinfo.vendor = dev->hid->vendor; | |
250 | dinfo.product = dev->hid->product; | |
251 | if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) | |
252 | return -EFAULT; | |
253 | ||
254 | return 0; | |
255 | } | |
256 | default: | |
257 | printk(KERN_EMERG "hidraw: unsupported ioctl() %x\n", | |
258 | cmd); | |
259 | } | |
260 | return -EINVAL; | |
261 | } | |
262 | ||
263 | static const struct file_operations hidraw_ops = { | |
264 | .owner = THIS_MODULE, | |
265 | .read = hidraw_read, | |
266 | .write = hidraw_write, | |
267 | .poll = hidraw_poll, | |
268 | .open = hidraw_open, | |
269 | .release = hidraw_release, | |
270 | .ioctl = hidraw_ioctl, | |
271 | }; | |
272 | ||
273 | void hidraw_report_event(struct hid_device *hid, u8 *data, int len) | |
274 | { | |
275 | struct hidraw *dev = hid->hidraw; | |
276 | struct hidraw_list *list; | |
277 | ||
278 | list_for_each_entry(list, &dev->list, node) { | |
279 | list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); | |
280 | list->buffer[list->head].len = len; | |
281 | list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
282 | kill_fasync(&list->fasync, SIGIO, POLL_IN); | |
283 | } | |
284 | ||
285 | wake_up_interruptible(&dev->wait); | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(hidraw_report_event); | |
288 | ||
289 | int hidraw_connect(struct hid_device *hid) | |
290 | { | |
709d27c0 | 291 | int minor, result; |
86166b7b JK |
292 | struct hidraw *dev; |
293 | ||
294 | /* TODO currently we accept any HID device. This should later | |
295 | * probably be fixed to accept only those devices which provide | |
296 | * non-input applications | |
297 | */ | |
298 | ||
709d27c0 MK |
299 | dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); |
300 | if (!dev) | |
301 | return -ENOMEM; | |
302 | ||
303 | result = -EINVAL; | |
86166b7b JK |
304 | |
305 | spin_lock(&minors_lock); | |
306 | ||
307 | for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { | |
308 | if (hidraw_table[minor]) | |
309 | continue; | |
310 | hidraw_table[minor] = dev; | |
311 | result = 0; | |
312 | break; | |
313 | } | |
314 | ||
315 | spin_unlock(&minors_lock); | |
316 | ||
709d27c0 MK |
317 | if (result) { |
318 | kfree(dev); | |
86166b7b | 319 | goto out; |
709d27c0 | 320 | } |
86166b7b JK |
321 | |
322 | dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor), | |
323 | "%s%d", "hidraw", minor); | |
324 | ||
325 | if (IS_ERR(dev->dev)) { | |
326 | spin_lock(&minors_lock); | |
327 | hidraw_table[minor] = NULL; | |
328 | spin_unlock(&minors_lock); | |
329 | result = PTR_ERR(dev->dev); | |
709d27c0 | 330 | kfree(dev); |
86166b7b JK |
331 | goto out; |
332 | } | |
333 | ||
334 | init_waitqueue_head(&dev->wait); | |
335 | INIT_LIST_HEAD(&dev->list); | |
336 | ||
337 | dev->hid = hid; | |
338 | dev->minor = minor; | |
339 | ||
340 | dev->exist = 1; | |
341 | hid->hidraw = dev; | |
342 | ||
343 | out: | |
344 | return result; | |
345 | ||
346 | } | |
347 | EXPORT_SYMBOL_GPL(hidraw_connect); | |
348 | ||
349 | void hidraw_disconnect(struct hid_device *hid) | |
350 | { | |
351 | struct hidraw *hidraw = hid->hidraw; | |
352 | ||
353 | hidraw->exist = 0; | |
354 | ||
355 | spin_lock(&minors_lock); | |
356 | hidraw_table[hidraw->minor] = NULL; | |
357 | spin_unlock(&minors_lock); | |
358 | ||
359 | device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); | |
360 | ||
361 | if (hidraw->open) { | |
362 | hid->hid_close(hid); | |
363 | wake_up_interruptible(&hidraw->wait); | |
364 | } else { | |
365 | kfree(hidraw); | |
366 | } | |
367 | } | |
368 | EXPORT_SYMBOL_GPL(hidraw_disconnect); | |
369 | ||
370 | int __init hidraw_init(void) | |
371 | { | |
372 | int result; | |
373 | dev_t dev_id; | |
374 | ||
375 | result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, | |
376 | HIDRAW_MAX_DEVICES, "hidraw"); | |
377 | ||
378 | hidraw_major = MAJOR(dev_id); | |
379 | ||
380 | if (result < 0) { | |
381 | printk(KERN_WARNING "hidraw: can't get major number\n"); | |
382 | result = 0; | |
383 | goto out; | |
384 | } | |
385 | ||
386 | hidraw_class = class_create(THIS_MODULE, "hidraw"); | |
387 | if (IS_ERR(hidraw_class)) { | |
388 | result = PTR_ERR(hidraw_class); | |
389 | unregister_chrdev(hidraw_major, "hidraw"); | |
390 | goto out; | |
391 | } | |
392 | ||
393 | cdev_init(&hidraw_cdev, &hidraw_ops); | |
394 | cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); | |
395 | out: | |
396 | return result; | |
397 | } | |
398 | ||
399 | void __exit hidraw_exit(void) | |
400 | { | |
401 | dev_t dev_id = MKDEV(hidraw_major, 0); | |
402 | ||
403 | cdev_del(&hidraw_cdev); | |
404 | class_destroy(hidraw_class); | |
405 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); | |
406 | ||
407 | } |