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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> | |
702e57d9 | 33 | #include <linux/smp_lock.h> |
86166b7b JK |
34 | |
35 | #include <linux/hidraw.h> | |
36 | ||
37 | static int hidraw_major; | |
38 | static struct cdev hidraw_cdev; | |
39 | static struct class *hidraw_class; | |
40 | static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES]; | |
41 | static DEFINE_SPINLOCK(minors_lock); | |
42 | ||
43 | static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) | |
44 | { | |
45 | struct hidraw_list *list = file->private_data; | |
46 | int ret = 0, len; | |
47 | char *report; | |
48 | DECLARE_WAITQUEUE(wait, current); | |
49 | ||
50 | while (ret == 0) { | |
51 | ||
52 | mutex_lock(&list->read_mutex); | |
53 | ||
54 | if (list->head == list->tail) { | |
55 | add_wait_queue(&list->hidraw->wait, &wait); | |
56 | set_current_state(TASK_INTERRUPTIBLE); | |
57 | ||
58 | while (list->head == list->tail) { | |
59 | if (file->f_flags & O_NONBLOCK) { | |
60 | ret = -EAGAIN; | |
61 | break; | |
62 | } | |
63 | if (signal_pending(current)) { | |
64 | ret = -ERESTARTSYS; | |
65 | break; | |
66 | } | |
67 | if (!list->hidraw->exist) { | |
68 | ret = -EIO; | |
69 | break; | |
70 | } | |
71 | ||
72 | /* allow O_NONBLOCK to work well from other threads */ | |
73 | mutex_unlock(&list->read_mutex); | |
74 | schedule(); | |
75 | mutex_lock(&list->read_mutex); | |
76 | set_current_state(TASK_INTERRUPTIBLE); | |
77 | } | |
78 | ||
79 | set_current_state(TASK_RUNNING); | |
80 | remove_wait_queue(&list->hidraw->wait, &wait); | |
81 | } | |
82 | ||
83 | if (ret) | |
84 | goto out; | |
85 | ||
86 | report = list->buffer[list->tail].value; | |
87 | len = list->buffer[list->tail].len > count ? | |
88 | count : list->buffer[list->tail].len; | |
89 | ||
90 | if (copy_to_user(buffer, list->buffer[list->tail].value, len)) { | |
91 | ret = -EFAULT; | |
92 | goto out; | |
93 | } | |
94 | ret += len; | |
95 | ||
96 | kfree(list->buffer[list->tail].value); | |
97 | list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
98 | } | |
99 | out: | |
100 | mutex_unlock(&list->read_mutex); | |
101 | return ret; | |
102 | } | |
103 | ||
104 | /* the first byte is expected to be a report number */ | |
105 | static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) | |
106 | { | |
107 | unsigned int minor = iminor(file->f_path.dentry->d_inode); | |
979c407e | 108 | /* FIXME: What stops hidraw_table going NULL */ |
86166b7b JK |
109 | struct hid_device *dev = hidraw_table[minor]->hid; |
110 | __u8 *buf; | |
111 | int ret = 0; | |
112 | ||
113 | if (!dev->hid_output_raw_report) | |
114 | return -ENODEV; | |
115 | ||
2b107d62 | 116 | if (count > HID_MAX_BUFFER_SIZE) { |
86166b7b | 117 | printk(KERN_WARNING "hidraw: pid %d passed too large report\n", |
ba25f9dc | 118 | task_pid_nr(current)); |
86166b7b JK |
119 | return -EINVAL; |
120 | } | |
121 | ||
122 | if (count < 2) { | |
123 | printk(KERN_WARNING "hidraw: pid %d passed too short report\n", | |
ba25f9dc | 124 | task_pid_nr(current)); |
86166b7b JK |
125 | return -EINVAL; |
126 | } | |
127 | ||
128 | buf = kmalloc(count * sizeof(__u8), GFP_KERNEL); | |
129 | if (!buf) | |
130 | return -ENOMEM; | |
131 | ||
132 | if (copy_from_user(buf, buffer, count)) { | |
133 | ret = -EFAULT; | |
134 | goto out; | |
135 | } | |
136 | ||
137 | ret = dev->hid_output_raw_report(dev, buf, count); | |
138 | out: | |
139 | kfree(buf); | |
140 | return ret; | |
141 | } | |
142 | ||
143 | static unsigned int hidraw_poll(struct file *file, poll_table *wait) | |
144 | { | |
145 | struct hidraw_list *list = file->private_data; | |
146 | ||
147 | poll_wait(file, &list->hidraw->wait, wait); | |
148 | if (list->head != list->tail) | |
149 | return POLLIN | POLLRDNORM; | |
150 | if (!list->hidraw->exist) | |
151 | return POLLERR | POLLHUP; | |
152 | return 0; | |
153 | } | |
154 | ||
155 | static int hidraw_open(struct inode *inode, struct file *file) | |
156 | { | |
157 | unsigned int minor = iminor(inode); | |
158 | struct hidraw *dev; | |
159 | struct hidraw_list *list; | |
160 | int err = 0; | |
161 | ||
702e57d9 | 162 | lock_kernel(); |
86166b7b JK |
163 | if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) { |
164 | err = -ENOMEM; | |
165 | goto out; | |
166 | } | |
167 | ||
168 | spin_lock(&minors_lock); | |
169 | if (!hidraw_table[minor]) { | |
170 | printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", | |
171 | minor); | |
172 | kfree(list); | |
173 | err = -ENODEV; | |
174 | goto out_unlock; | |
175 | } | |
176 | ||
177 | list->hidraw = hidraw_table[minor]; | |
178 | mutex_init(&list->read_mutex); | |
179 | list_add_tail(&list->node, &hidraw_table[minor]->list); | |
180 | file->private_data = list; | |
181 | ||
182 | dev = hidraw_table[minor]; | |
183 | if (!dev->open++) | |
c500c971 | 184 | dev->hid->ll_driver->open(dev->hid); |
86166b7b JK |
185 | |
186 | out_unlock: | |
187 | spin_unlock(&minors_lock); | |
188 | out: | |
702e57d9 | 189 | unlock_kernel(); |
86166b7b JK |
190 | return err; |
191 | ||
192 | } | |
193 | ||
194 | static int hidraw_release(struct inode * inode, struct file * file) | |
195 | { | |
196 | unsigned int minor = iminor(inode); | |
197 | struct hidraw *dev; | |
198 | struct hidraw_list *list = file->private_data; | |
199 | ||
200 | if (!hidraw_table[minor]) { | |
201 | printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", | |
202 | minor); | |
203 | return -ENODEV; | |
204 | } | |
205 | ||
206 | list_del(&list->node); | |
207 | dev = hidraw_table[minor]; | |
208 | if (!dev->open--) { | |
209 | if (list->hidraw->exist) | |
c500c971 | 210 | dev->hid->ll_driver->close(dev->hid); |
86166b7b JK |
211 | else |
212 | kfree(list->hidraw); | |
213 | } | |
214 | ||
4db1c62c JK |
215 | kfree(list); |
216 | ||
86166b7b JK |
217 | return 0; |
218 | } | |
219 | ||
979c407e AC |
220 | static long hidraw_ioctl(struct file *file, unsigned int cmd, |
221 | unsigned long arg) | |
86166b7b | 222 | { |
979c407e | 223 | struct inode *inode = file->f_path.dentry->d_inode; |
86166b7b | 224 | unsigned int minor = iminor(inode); |
979c407e AC |
225 | long ret = 0; |
226 | /* FIXME: What stops hidraw_table going NULL */ | |
86166b7b JK |
227 | struct hidraw *dev = hidraw_table[minor]; |
228 | void __user *user_arg = (void __user*) arg; | |
229 | ||
979c407e | 230 | lock_kernel(); |
86166b7b JK |
231 | switch (cmd) { |
232 | case HIDIOCGRDESCSIZE: | |
233 | if (put_user(dev->hid->rsize, (int __user *)arg)) | |
979c407e AC |
234 | ret = -EFAULT; |
235 | break; | |
86166b7b JK |
236 | |
237 | case HIDIOCGRDESC: | |
238 | { | |
239 | __u32 len; | |
240 | ||
241 | if (get_user(len, (int __user *)arg)) | |
979c407e AC |
242 | ret = -EFAULT; |
243 | else if (len > HID_MAX_DESCRIPTOR_SIZE - 1) | |
244 | ret = -EINVAL; | |
245 | else if (copy_to_user(user_arg + offsetof( | |
246 | struct hidraw_report_descriptor, | |
247 | value[0]), | |
248 | dev->hid->rdesc, | |
249 | min(dev->hid->rsize, len))) | |
250 | ret = -EFAULT; | |
251 | break; | |
86166b7b JK |
252 | } |
253 | case HIDIOCGRAWINFO: | |
254 | { | |
255 | struct hidraw_devinfo dinfo; | |
256 | ||
257 | dinfo.bustype = dev->hid->bus; | |
258 | dinfo.vendor = dev->hid->vendor; | |
259 | dinfo.product = dev->hid->product; | |
260 | if (copy_to_user(user_arg, &dinfo, sizeof(dinfo))) | |
979c407e AC |
261 | ret = -EFAULT; |
262 | break; | |
86166b7b JK |
263 | } |
264 | default: | |
979c407e | 265 | ret = -ENOTTY; |
86166b7b | 266 | } |
979c407e | 267 | return ret; |
86166b7b JK |
268 | } |
269 | ||
270 | static const struct file_operations hidraw_ops = { | |
271 | .owner = THIS_MODULE, | |
272 | .read = hidraw_read, | |
273 | .write = hidraw_write, | |
274 | .poll = hidraw_poll, | |
275 | .open = hidraw_open, | |
276 | .release = hidraw_release, | |
979c407e | 277 | .unlocked_ioctl = hidraw_ioctl, |
86166b7b JK |
278 | }; |
279 | ||
280 | void hidraw_report_event(struct hid_device *hid, u8 *data, int len) | |
281 | { | |
282 | struct hidraw *dev = hid->hidraw; | |
283 | struct hidraw_list *list; | |
284 | ||
285 | list_for_each_entry(list, &dev->list, node) { | |
286 | list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC); | |
287 | list->buffer[list->head].len = len; | |
288 | list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1); | |
289 | kill_fasync(&list->fasync, SIGIO, POLL_IN); | |
290 | } | |
291 | ||
292 | wake_up_interruptible(&dev->wait); | |
293 | } | |
294 | EXPORT_SYMBOL_GPL(hidraw_report_event); | |
295 | ||
296 | int hidraw_connect(struct hid_device *hid) | |
297 | { | |
709d27c0 | 298 | int minor, result; |
86166b7b JK |
299 | struct hidraw *dev; |
300 | ||
301 | /* TODO currently we accept any HID device. This should later | |
302 | * probably be fixed to accept only those devices which provide | |
303 | * non-input applications | |
304 | */ | |
305 | ||
709d27c0 MK |
306 | dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL); |
307 | if (!dev) | |
308 | return -ENOMEM; | |
309 | ||
310 | result = -EINVAL; | |
86166b7b JK |
311 | |
312 | spin_lock(&minors_lock); | |
313 | ||
314 | for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { | |
315 | if (hidraw_table[minor]) | |
316 | continue; | |
317 | hidraw_table[minor] = dev; | |
318 | result = 0; | |
319 | break; | |
320 | } | |
321 | ||
322 | spin_unlock(&minors_lock); | |
323 | ||
709d27c0 MK |
324 | if (result) { |
325 | kfree(dev); | |
86166b7b | 326 | goto out; |
709d27c0 | 327 | } |
86166b7b | 328 | |
0fd15a18 GKH |
329 | dev->dev = device_create_drvdata(hidraw_class, NULL, |
330 | MKDEV(hidraw_major, minor), NULL, | |
331 | "%s%d", "hidraw", minor); | |
86166b7b JK |
332 | |
333 | if (IS_ERR(dev->dev)) { | |
334 | spin_lock(&minors_lock); | |
335 | hidraw_table[minor] = NULL; | |
336 | spin_unlock(&minors_lock); | |
337 | result = PTR_ERR(dev->dev); | |
709d27c0 | 338 | kfree(dev); |
86166b7b JK |
339 | goto out; |
340 | } | |
341 | ||
342 | init_waitqueue_head(&dev->wait); | |
343 | INIT_LIST_HEAD(&dev->list); | |
344 | ||
345 | dev->hid = hid; | |
346 | dev->minor = minor; | |
347 | ||
348 | dev->exist = 1; | |
349 | hid->hidraw = dev; | |
350 | ||
351 | out: | |
352 | return result; | |
353 | ||
354 | } | |
355 | EXPORT_SYMBOL_GPL(hidraw_connect); | |
356 | ||
357 | void hidraw_disconnect(struct hid_device *hid) | |
358 | { | |
359 | struct hidraw *hidraw = hid->hidraw; | |
360 | ||
361 | hidraw->exist = 0; | |
362 | ||
363 | spin_lock(&minors_lock); | |
364 | hidraw_table[hidraw->minor] = NULL; | |
365 | spin_unlock(&minors_lock); | |
366 | ||
367 | device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); | |
368 | ||
369 | if (hidraw->open) { | |
c500c971 | 370 | hid->ll_driver->close(hid); |
86166b7b JK |
371 | wake_up_interruptible(&hidraw->wait); |
372 | } else { | |
373 | kfree(hidraw); | |
374 | } | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(hidraw_disconnect); | |
377 | ||
378 | int __init hidraw_init(void) | |
379 | { | |
380 | int result; | |
381 | dev_t dev_id; | |
382 | ||
383 | result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR, | |
384 | HIDRAW_MAX_DEVICES, "hidraw"); | |
385 | ||
386 | hidraw_major = MAJOR(dev_id); | |
387 | ||
388 | if (result < 0) { | |
389 | printk(KERN_WARNING "hidraw: can't get major number\n"); | |
390 | result = 0; | |
391 | goto out; | |
392 | } | |
393 | ||
394 | hidraw_class = class_create(THIS_MODULE, "hidraw"); | |
395 | if (IS_ERR(hidraw_class)) { | |
396 | result = PTR_ERR(hidraw_class); | |
397 | unregister_chrdev(hidraw_major, "hidraw"); | |
398 | goto out; | |
399 | } | |
400 | ||
401 | cdev_init(&hidraw_cdev, &hidraw_ops); | |
402 | cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES); | |
403 | out: | |
404 | return result; | |
405 | } | |
406 | ||
407 | void __exit hidraw_exit(void) | |
408 | { | |
409 | dev_t dev_id = MKDEV(hidraw_major, 0); | |
410 | ||
411 | cdev_del(&hidraw_cdev); | |
412 | class_destroy(hidraw_class); | |
413 | unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES); | |
414 | ||
415 | } |