evdev.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 
1/*
2 * Event char devices, giving access to raw input device events.
3 *
4 * Copyright (c) 1999-2002 Vojtech Pavlik
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 */
10
11#define EVDEV_MINOR_BASE	64
12#define EVDEV_MINORS		32
13#define EVDEV_BUFFER_SIZE	64
14
15#include <linux/poll.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/input.h>
20#include <linux/major.h>
21#include <linux/smp_lock.h>
22#include <linux/device.h>
23#include <linux/devfs_fs_kernel.h>
24
25struct evdev {
26	int exist;
27	int open;
28	int minor;
29	char name[16];
30	struct input_handle handle;
31	wait_queue_head_t wait;
32	struct evdev_list *grab;
33	struct list_head list;
34};
35
36struct evdev_list {
37	struct input_event buffer[EVDEV_BUFFER_SIZE];
38	int head;
39	int tail;
40	struct fasync_struct *fasync;
41	struct evdev *evdev;
42	struct list_head node;
43};
44
45static struct evdev *evdev_table[EVDEV_MINORS];
46
47static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
48{
49	struct evdev *evdev = handle->private;
50	struct evdev_list *list;
51
52	if (evdev->grab) {
53		list = evdev->grab;
54
55		do_gettimeofday(&list->buffer[list->head].time);
56		list->buffer[list->head].type = type;
57		list->buffer[list->head].code = code;
58		list->buffer[list->head].value = value;
59		list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
60
61		kill_fasync(&list->fasync, SIGIO, POLL_IN);
62	} else
63		list_for_each_entry(list, &evdev->list, node) {
64
65			do_gettimeofday(&list->buffer[list->head].time);
66			list->buffer[list->head].type = type;
67			list->buffer[list->head].code = code;
68			list->buffer[list->head].value = value;
69			list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
70
71			kill_fasync(&list->fasync, SIGIO, POLL_IN);
72		}
73
74	wake_up_interruptible(&evdev->wait);
75}
76
77static int evdev_fasync(int fd, struct file *file, int on)
78{
79	int retval;
80	struct evdev_list *list = file->private_data;
81	retval = fasync_helper(fd, file, on, &list->fasync);
82	return retval < 0 ? retval : 0;
83}
84
85static int evdev_flush(struct file * file)
86{
87	struct evdev_list *list = file->private_data;
88	if (!list->evdev->exist) return -ENODEV;
89	return input_flush_device(&list->evdev->handle, file);
90}
91
92static void evdev_free(struct evdev *evdev)
93{
94	evdev_table[evdev->minor] = NULL;
95	kfree(evdev);
96}
97
98static int evdev_release(struct inode * inode, struct file * file)
99{
100	struct evdev_list *list = file->private_data;
101
102	if (list->evdev->grab == list) {
103		input_release_device(&list->evdev->handle);
104		list->evdev->grab = NULL;
105	}
106
107	evdev_fasync(-1, file, 0);
108	list_del(&list->node);
109
110	if (!--list->evdev->open) {
111		if (list->evdev->exist)
112			input_close_device(&list->evdev->handle);
113		else
114			evdev_free(list->evdev);
115	}
116
117	kfree(list);
118	return 0;
119}
120
121static int evdev_open(struct inode * inode, struct file * file)
122{
123	struct evdev_list *list;
124	int i = iminor(inode) - EVDEV_MINOR_BASE;
125	int accept_err;
126
127	if (i >= EVDEV_MINORS || !evdev_table[i] || !evdev_table[i]->exist)
128		return -ENODEV;
129
130	if ((accept_err = input_accept_process(&(evdev_table[i]->handle), file)))
131		return accept_err;
132
133	if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
134		return -ENOMEM;
135	memset(list, 0, sizeof(struct evdev_list));
136
137	list->evdev = evdev_table[i];
138	list_add_tail(&list->node, &evdev_table[i]->list);
139	file->private_data = list;
140
141	if (!list->evdev->open++)
142		if (list->evdev->exist)
143			input_open_device(&list->evdev->handle);
144
145	return 0;
146}
147
148static ssize_t evdev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
149{
150	struct evdev_list *list = file->private_data;
151	struct input_event event;
152	int retval = 0;
153
154	if (!list->evdev->exist) return -ENODEV;
155
156	while (retval < count) {
157
158		if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
159			return -EFAULT;
160		input_event(list->evdev->handle.dev, event.type, event.code, event.value);
161		retval += sizeof(struct input_event);
162	}
163
164	return retval;
165}
166
167static ssize_t evdev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
168{
169	struct evdev_list *list = file->private_data;
170	int retval;
171
172	if (count < sizeof(struct input_event))
173		return -EINVAL;
174
175	if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
176		return -EAGAIN;
177
178	retval = wait_event_interruptible(list->evdev->wait,
179		list->head != list->tail || (!list->evdev->exist));
180
181	if (retval)
182		return retval;
183
184	if (!list->evdev->exist)
185		return -ENODEV;
186
187	while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
188		if (copy_to_user(buffer + retval, list->buffer + list->tail,
189			 sizeof(struct input_event))) return -EFAULT;
190		list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
191		retval += sizeof(struct input_event);
192	}
193
194	return retval;
195}
196
197/* No kernel lock - fine */
198static unsigned int evdev_poll(struct file *file, poll_table *wait)
199{
200	struct evdev_list *list = file->private_data;
201	poll_wait(file, &list->evdev->wait, wait);
202	return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
203		(list->evdev->exist ? 0 : (POLLHUP | POLLERR));
204}
205
206static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
207{
208	struct evdev_list *list = file->private_data;
209	struct evdev *evdev = list->evdev;
210	struct input_dev *dev = evdev->handle.dev;
211	struct input_absinfo abs;
212	void __user *p = (void __user *)arg;
213	int __user *ip = (int __user *)arg;
214	int i, t, u, v;
215
216	if (!evdev->exist) return -ENODEV;
217
218	switch (cmd) {
219
220		case EVIOCGVERSION:
221			return put_user(EV_VERSION, ip);
222
223		case EVIOCGID:
224			return copy_to_user(p, &dev->id, sizeof(struct input_id)) ? -EFAULT : 0;
225
226		case EVIOCGKEYCODE:
227			if (get_user(t, ip)) return -EFAULT;
228			if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
229			if (put_user(INPUT_KEYCODE(dev, t), ip + 1)) return -EFAULT;
230			return 0;
231
232		case EVIOCSKEYCODE:
233			if (get_user(t, ip)) return -EFAULT;
234			if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
235			if (get_user(v, ip + 1)) return -EFAULT;
236			if (v < 0 || v > KEY_MAX) return -EINVAL;
237			u = SET_INPUT_KEYCODE(dev, t, v);
238			clear_bit(u, dev->keybit);
239			set_bit(v, dev->keybit);
240			for (i = 0; i < dev->keycodemax; i++)
241				if (INPUT_KEYCODE(dev,i) == u)
242					set_bit(u, dev->keybit);
243			return 0;
244
245		case EVIOCSFF:
246			if (dev->upload_effect) {
247				struct ff_effect effect;
248				int err;
249
250				if (copy_from_user(&effect, p, sizeof(effect)))
251					return -EFAULT;
252				err = dev->upload_effect(dev, &effect);
253				if (put_user(effect.id, &(((struct ff_effect __user *)arg)->id)))
254					return -EFAULT;
255				return err;
256			}
257			else return -ENOSYS;
258
259		case EVIOCRMFF:
260			if (dev->erase_effect) {
261				return dev->erase_effect(dev, (int)arg);
262			}
263			else return -ENOSYS;
264
265		case EVIOCGEFFECTS:
266			if (put_user(dev->ff_effects_max, ip))
267				return -EFAULT;
268			return 0;
269
270		case EVIOCGRAB:
271			if (arg) {
272				if (evdev->grab)
273					return -EBUSY;
274				if (input_grab_device(&evdev->handle))
275					return -EBUSY;
276				evdev->grab = list;
277				return 0;
278			} else {
279				if (evdev->grab != list)
280					return -EINVAL;
281				input_release_device(&evdev->handle);
282				evdev->grab = NULL;
283				return 0;
284			}
285
286		default:
287
288			if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
289				return -EINVAL;
290
291			if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
292
293				long *bits;
294				int len;
295
296				switch (_IOC_NR(cmd) & EV_MAX) {
297					case      0: bits = dev->evbit;  len = EV_MAX;  break;
298					case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
299					case EV_REL: bits = dev->relbit; len = REL_MAX; break;
300					case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
301					case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
302					case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
303					case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
304					case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
305					default: return -EINVAL;
306				}
307				len = NBITS(len) * sizeof(long);
308				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
309				return copy_to_user(p, bits, len) ? -EFAULT : len;
310			}
311
312			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) {
313				int len;
314				len = NBITS(KEY_MAX) * sizeof(long);
315				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
316				return copy_to_user(p, dev->key, len) ? -EFAULT : len;
317			}
318
319			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) {
320				int len;
321				len = NBITS(LED_MAX) * sizeof(long);
322				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
323				return copy_to_user(p, dev->led, len) ? -EFAULT : len;
324			}
325
326			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) {
327				int len;
328				len = NBITS(SND_MAX) * sizeof(long);
329				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
330				return copy_to_user(p, dev->snd, len) ? -EFAULT : len;
331			}
332
333			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
334				int len;
335				if (!dev->name) return -ENOENT;
336				len = strlen(dev->name) + 1;
337				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
338				return copy_to_user(p, dev->name, len) ? -EFAULT : len;
339			}
340
341			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
342				int len;
343				if (!dev->phys) return -ENOENT;
344				len = strlen(dev->phys) + 1;
345				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
346				return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
347			}
348
349			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
350				int len;
351				if (!dev->uniq) return -ENOENT;
352				len = strlen(dev->uniq) + 1;
353				if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
354				return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
355			}
356
357			if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
358
359				int t = _IOC_NR(cmd) & ABS_MAX;
360
361				abs.value = dev->abs[t];
362				abs.minimum = dev->absmin[t];
363				abs.maximum = dev->absmax[t];
364				abs.fuzz = dev->absfuzz[t];
365				abs.flat = dev->absflat[t];
366
367				if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
368					return -EFAULT;
369
370				return 0;
371			}
372
373			if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
374
375				int t = _IOC_NR(cmd) & ABS_MAX;
376
377				if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
378					return -EFAULT;
379
380				dev->abs[t] = abs.value;
381				dev->absmin[t] = abs.minimum;
382				dev->absmax[t] = abs.maximum;
383				dev->absfuzz[t] = abs.fuzz;
384				dev->absflat[t] = abs.flat;
385
386				return 0;
387			}
388	}
389	return -EINVAL;
390}
391
392static struct file_operations evdev_fops = {
393	.owner =	THIS_MODULE,
394	.read =		evdev_read,
395	.write =	evdev_write,
396	.poll =		evdev_poll,
397	.open =		evdev_open,
398	.release =	evdev_release,
399	.ioctl =	evdev_ioctl,
400	.fasync =	evdev_fasync,
401	.flush =	evdev_flush
402};
403
404static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
405{
406	struct evdev *evdev;
407	int minor;
408
409	for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++);
410	if (minor == EVDEV_MINORS) {
411		printk(KERN_ERR "evdev: no more free evdev devices\n");
412		return NULL;
413	}
414
415	if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
416		return NULL;
417	memset(evdev, 0, sizeof(struct evdev));
418
419	INIT_LIST_HEAD(&evdev->list);
420	init_waitqueue_head(&evdev->wait);
421
422	evdev->exist = 1;
423	evdev->minor = minor;
424	evdev->handle.dev = dev;
425	evdev->handle.name = evdev->name;
426	evdev->handle.handler = handler;
427	evdev->handle.private = evdev;
428	sprintf(evdev->name, "event%d", minor);
429
430	evdev_table[minor] = evdev;
431
432	devfs_mk_cdev(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
433			S_IFCHR|S_IRUGO|S_IWUSR, "input/event%d", minor);
434	class_simple_device_add(input_class,
435				MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
436				dev->dev, "event%d", minor);
437
438	return &evdev->handle;
439}
440
441static void evdev_disconnect(struct input_handle *handle)
442{
443	struct evdev *evdev = handle->private;
444	struct evdev_list *list;
445
446	class_simple_device_remove(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
447	devfs_remove("input/event%d", evdev->minor);
448	evdev->exist = 0;
449
450	if (evdev->open) {
451		input_close_device(handle);
452		wake_up_interruptible(&evdev->wait);
453		list_for_each_entry(list, &evdev->list, node)
454			kill_fasync(&list->fasync, SIGIO, POLL_HUP);
455	} else
456		evdev_free(evdev);
457}
458
459static struct input_device_id evdev_ids[] = {
460	{ .driver_info = 1 },	/* Matches all devices */
461	{ },			/* Terminating zero entry */
462};
463
464MODULE_DEVICE_TABLE(input, evdev_ids);
465
466static struct input_handler evdev_handler = {
467	.event =	evdev_event,
468	.connect =	evdev_connect,
469	.disconnect =	evdev_disconnect,
470	.fops =		&evdev_fops,
471	.minor =	EVDEV_MINOR_BASE,
472	.name =		"evdev",
473	.id_table =	evdev_ids,
474};
475
476static int __init evdev_init(void)
477{
478	input_register_handler(&evdev_handler);
479	return 0;
480}
481
482static void __exit evdev_exit(void)
483{
484	input_unregister_handler(&evdev_handler);
485}
486
487module_init(evdev_init);
488module_exit(evdev_exit);
489
490MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
491MODULE_DESCRIPTION("Input driver event char devices");
492MODULE_LICENSE("GPL");
493