blob: 20ebba1032b8a99b795d5cf9ebf322e388602be9 [file] [log] [blame]
Jiri Kosina86166b72007-05-14 09:57:40 +02001/*
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
36static int hidraw_major;
37static struct cdev hidraw_cdev;
38static struct class *hidraw_class;
39static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
40static DEFINE_SPINLOCK(minors_lock);
41
42static 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 }
98out:
99 mutex_unlock(&list->read_mutex);
100 return ret;
101}
102
103/* the first byte is expected to be a report number */
104static 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",
116 current->pid);
117 return -EINVAL;
118 }
119
120 if (count < 2) {
121 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
122 current->pid);
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);
136out:
137 kfree(buf);
138 return ret;
139}
140
141static 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
153static 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
183out_unlock:
184 spin_unlock(&minors_lock);
185out:
186 return err;
187
188}
189
190static 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
214static 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;
232 if (copy_to_user(*((__u8 **)(user_arg +
233 sizeof(__u32))),
234 dev->hid->rdesc, len))
235 return -EFAULT;
236 return 0;
237 }
238 case HIDIOCGRAWINFO:
239 {
240 struct hidraw_devinfo dinfo;
241
242 dinfo.bustype = dev->hid->bus;
243 dinfo.vendor = dev->hid->vendor;
244 dinfo.product = dev->hid->product;
245 if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
246 return -EFAULT;
247
248 return 0;
249 }
250 default:
251 printk(KERN_EMERG "hidraw: unsupported ioctl() %x\n",
252 cmd);
253 }
254 return -EINVAL;
255}
256
257static const struct file_operations hidraw_ops = {
258 .owner = THIS_MODULE,
259 .read = hidraw_read,
260 .write = hidraw_write,
261 .poll = hidraw_poll,
262 .open = hidraw_open,
263 .release = hidraw_release,
264 .ioctl = hidraw_ioctl,
265};
266
267void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
268{
269 struct hidraw *dev = hid->hidraw;
270 struct hidraw_list *list;
271
272 list_for_each_entry(list, &dev->list, node) {
273 list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
274 list->buffer[list->head].len = len;
275 list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
276 kill_fasync(&list->fasync, SIGIO, POLL_IN);
277 }
278
279 wake_up_interruptible(&dev->wait);
280}
281EXPORT_SYMBOL_GPL(hidraw_report_event);
282
283int hidraw_connect(struct hid_device *hid)
284{
285 int minor, result = -EINVAL;
286 struct hidraw *dev;
287
288 /* TODO currently we accept any HID device. This should later
289 * probably be fixed to accept only those devices which provide
290 * non-input applications
291 */
292
293 if (!(dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL)))
294 return -1;
295
296 spin_lock(&minors_lock);
297
298 for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
299 if (hidraw_table[minor])
300 continue;
301 hidraw_table[minor] = dev;
302 result = 0;
303 break;
304 }
305
306 spin_unlock(&minors_lock);
307
308 if (result)
309 goto out;
310
311 dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor),
312 "%s%d", "hidraw", minor);
313
314 if (IS_ERR(dev->dev)) {
315 spin_lock(&minors_lock);
316 hidraw_table[minor] = NULL;
317 spin_unlock(&minors_lock);
318 result = PTR_ERR(dev->dev);
319 goto out;
320 }
321
322 init_waitqueue_head(&dev->wait);
323 INIT_LIST_HEAD(&dev->list);
324
325 dev->hid = hid;
326 dev->minor = minor;
327
328 dev->exist = 1;
329 hid->hidraw = dev;
330
331out:
332 return result;
333
334}
335EXPORT_SYMBOL_GPL(hidraw_connect);
336
337void hidraw_disconnect(struct hid_device *hid)
338{
339 struct hidraw *hidraw = hid->hidraw;
340
341 hidraw->exist = 0;
342
343 spin_lock(&minors_lock);
344 hidraw_table[hidraw->minor] = NULL;
345 spin_unlock(&minors_lock);
346
347 device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));
348
349 if (hidraw->open) {
350 hid->hid_close(hid);
351 wake_up_interruptible(&hidraw->wait);
352 } else {
353 kfree(hidraw);
354 }
355}
356EXPORT_SYMBOL_GPL(hidraw_disconnect);
357
358int __init hidraw_init(void)
359{
360 int result;
361 dev_t dev_id;
362
363 result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
364 HIDRAW_MAX_DEVICES, "hidraw");
365
366 hidraw_major = MAJOR(dev_id);
367
368 if (result < 0) {
369 printk(KERN_WARNING "hidraw: can't get major number\n");
370 result = 0;
371 goto out;
372 }
373
374 hidraw_class = class_create(THIS_MODULE, "hidraw");
375 if (IS_ERR(hidraw_class)) {
376 result = PTR_ERR(hidraw_class);
377 unregister_chrdev(hidraw_major, "hidraw");
378 goto out;
379 }
380
381 cdev_init(&hidraw_cdev, &hidraw_ops);
382 cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
383out:
384 return result;
385}
386
387void __exit hidraw_exit(void)
388{
389 dev_t dev_id = MKDEV(hidraw_major, 0);
390
391 cdev_del(&hidraw_cdev);
392 class_destroy(hidraw_class);
393 unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
394
395}