blob: 1ca6f4635eeb3e0474abada594892ac5683ce7ba [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",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700116 task_pid_nr(current));
Jiri Kosina86166b72007-05-14 09:57:40 +0200117 return -EINVAL;
118 }
119
120 if (count < 2) {
121 printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700122 task_pid_nr(current));
Jiri Kosina86166b72007-05-14 09:57:40 +0200123 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;
Jiri Kosina57d292b2007-10-15 15:17:41 +0200232
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)))
Jiri Kosina86166b72007-05-14 09:57:40 +0200241 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
263static 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
273void 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}
287EXPORT_SYMBOL_GPL(hidraw_report_event);
288
289int hidraw_connect(struct hid_device *hid)
290{
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200291 int minor, result;
Jiri Kosina86166b72007-05-14 09:57:40 +0200292 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
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200299 dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
300 if (!dev)
301 return -ENOMEM;
302
303 result = -EINVAL;
Jiri Kosina86166b72007-05-14 09:57:40 +0200304
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
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200317 if (result) {
318 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200319 goto out;
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200320 }
Jiri Kosina86166b72007-05-14 09:57:40 +0200321
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);
Mariusz Kozlowski709d27c2007-09-27 11:24:55 +0200330 kfree(dev);
Jiri Kosina86166b72007-05-14 09:57:40 +0200331 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
343out:
344 return result;
345
346}
347EXPORT_SYMBOL_GPL(hidraw_connect);
348
349void 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}
368EXPORT_SYMBOL_GPL(hidraw_disconnect);
369
370int __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);
395out:
396 return result;
397}
398
399void __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}