aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/tsdev.c
blob: 5e5b5c91d75b1286451ff30b84ccf6985da12ff4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
/*
 * $Id: tsdev.c,v 1.15 2002/04/10 16:50:19 jsimmons Exp $
 *
 *  Copyright (c) 2001 "Crazy" james Simmons
 *
 *  Compaq touchscreen protocol driver. The protocol emulated by this driver
 *  is obsolete; for new programs use the tslib library which can read directly
 *  from evdev and perform dejittering, variance filtering and calibration -
 *  all in user space, not at kernel level. The meaning of this driver is
 *  to allow usage of newer input drivers with old applications that use the
 *  old /dev/h3600_ts and /dev/h3600_tsraw devices.
 *
 *  09-Apr-2004: Andrew Zabolotny <zap@homelink.ru>
 *      Fixed to actually work, not just output random numbers.
 *      Added support for both h3600_ts and h3600_tsraw protocol
 *      emulation.
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <jsimmons@infradead.org>.
 */

#define TSDEV_MINOR_BASE	128
#define TSDEV_MINORS		32
/* First 16 devices are h3600_ts compatible; second 16 are h3600_tsraw */
#define TSDEV_MINOR_MASK	15
#define TSDEV_BUFFER_SIZE	64

#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/major.h>
#include <linux/smp_lock.h>
#include <linux/random.h>
#include <linux/time.h>
#include <linux/device.h>

#ifndef CONFIG_INPUT_TSDEV_SCREEN_X
#define CONFIG_INPUT_TSDEV_SCREEN_X	240
#endif
#ifndef CONFIG_INPUT_TSDEV_SCREEN_Y
#define CONFIG_INPUT_TSDEV_SCREEN_Y	320
#endif

/* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
 * devices. The first one must output X/Y data in 'cooked' format, e.g.
 * filtered, dejittered and calibrated. Second device just outputs raw
 * data received from the hardware.
 *
 * This driver doesn't support filtering and dejittering; it supports only
 * calibration. Filtering and dejittering must be done in the low-level
 * driver, if needed, because it may gain additional benefits from knowing
 * the low-level details, the nature of noise and so on.
 *
 * The driver precomputes a calibration matrix given the initial xres and
 * yres values (quite innacurate for most touchscreens) that will result
 * in a more or less expected range of output values. The driver supports
 * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
 * new one, supposedly generated from the values taken from the raw device.
 */

MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
MODULE_DESCRIPTION("Input driver to touchscreen converter");
MODULE_LICENSE("GPL");

static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
module_param(xres, uint, 0);
MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");

static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
module_param(yres, uint, 0);
MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");

/* From Compaq's Touch Screen Specification version 0.2 (draft) */
struct ts_event {
	short pressure;
	short x;
	short y;
	short millisecs;
};

struct ts_calibration {
	int xscale;
	int xtrans;
	int yscale;
	int ytrans;
	int xyswap;
};

struct tsdev {
	int exist;
	int open;
	int minor;
	char name[8];
	wait_queue_head_t wait;
	struct list_head client_list;
	struct input_handle handle;
	int x, y, pressure;
	struct ts_calibration cal;
};

struct tsdev_client {
	struct fasync_struct *fasync;
	struct list_head node;
	struct tsdev *tsdev;
	int head, tail;
	struct ts_event event[TSDEV_BUFFER_SIZE];
	int raw;
};

/* The following ioctl codes are defined ONLY for backward compatibility.
 * Don't use tsdev for new developement; use the tslib library instead.
 * Touchscreen calibration is a fully userspace task.
 */
/* Use 'f' as magic number */
#define IOC_H3600_TS_MAGIC  'f'
#define TS_GET_CAL	_IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
#define TS_SET_CAL	_IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)

static struct tsdev *tsdev_table[TSDEV_MINORS/2];

static int tsdev_fasync(int fd, struct file *file, int on)
{
	struct tsdev_client *client = file->private_data;
	int retval;

	retval = fasync_helper(fd, file, on, &client->fasync);
	return retval < 0 ? retval : 0;
}

static int tsdev_open(struct inode *inode, struct file *file)
{
	int i = iminor(inode) - TSDEV_MINOR_BASE;
	struct tsdev_client *client;
	struct tsdev *tsdev;
	int error;

	printk(KERN_WARNING "tsdev (compaq touchscreen emulation) is scheduled "
		"for removal.\nSee Documentation/feature-removal-schedule.txt "
		"for details.\n");

	if (i >= TSDEV_MINORS)
		return -ENODEV;

	tsdev = tsdev_table[i & TSDEV_MINOR_MASK];
	if (!tsdev || !tsdev->exist)
		return -ENODEV;

	client = kzalloc(sizeof(struct tsdev_client), GFP_KERNEL);
	if (!client)
		return -ENOMEM;

	client->tsdev = tsdev;
	client->raw = (i >= TSDEV_MINORS / 2) ? 1 : 0;
	list_add_tail(&client->node, &tsdev->client_list);

	if (!tsdev->open++ && tsdev->exist) {
		error = input_open_device(&tsdev->handle);
		if (error) {
			list_del(&client->node);
			kfree(client);
			return error;
		}
	}

	file->private_data = client;
	return 0;
}

static void tsdev_free(struct tsdev *tsdev)
{
	tsdev_table[tsdev->minor] = NULL;
	kfree(tsdev);
}

static int tsdev_release(struct inode *inode, struct file *file)
{
	struct tsdev_client *client = file->private_data;
	struct tsdev *tsdev = client->tsdev;

	tsdev_fasync(-1, file, 0);

	list_del(&client->node);
	kfree(client);

	if (!--tsdev->open) {
		if (tsdev->exist)
			input_close_device(&tsdev->handle);
		else
			tsdev_free(tsdev);
	}

	return 0;
}

static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
			  loff_t *ppos)
{
	struct tsdev_client *client = file->private_data;
	struct tsdev *tsdev = client->tsdev;
	int retval = 0;

	if (client->head == client->tail && tsdev->exist && (file->f_flags & O_NONBLOCK))
		return -EAGAIN;

	retval = wait_event_interruptible(tsdev->wait,
			client->head != client->tail || !tsdev->exist);
	if (retval)
		return retval;

	if (!tsdev->exist)
		return -ENODEV;

	while (client->head != client->tail &&
	       retval + sizeof (struct ts_event) <= count) {
		if (copy_to_user (buffer + retval, client->event + client->tail,
				  sizeof (struct ts_event)))
			return -EFAULT;
		client->tail = (client->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
		retval += sizeof (struct ts_event);
	}

	return retval;
}

/* No kernel lock - fine */
static unsigned int tsdev_poll(struct file *file, poll_table *wait)
{
	struct tsdev_client *client = file->private_data;
	struct tsdev *tsdev = client->tsdev;

	poll_wait(file, &tsdev->wait, wait);
	return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
		(tsdev->exist ? 0 : (POLLHUP | POLLERR));
}

static int tsdev_ioctl(struct inode *inode, struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	struct tsdev_client *client = file->private_data;
	struct tsdev *tsdev = client->tsdev;
	int retval = 0;

	switch (cmd) {
	case TS_GET_CAL:
		if (copy_to_user((void __user *)arg, &tsdev->cal,
				 sizeof (struct ts_calibration)))
			retval = -EFAULT;
		break;

	case TS_SET_CAL:
		if (copy_from_user(&tsdev->cal, (void __user *)arg,
				   sizeof (struct ts_calibration)))
			retval = -EFAULT;
		break;

	default:
		retval = -EINVAL;
		break;
	}

	return retval;
}

static const struct file_operations tsdev_fops = {
	.owner =	THIS_MODULE,
	.open =		tsdev_open,
	.release =	tsdev_release,
	.read =		tsdev_read,
	.poll =		tsdev_poll,
	.fasync =	tsdev_fasync,
	.ioctl =	tsdev_ioctl,
};

static void tsdev_event(struct input_handle *handle, unsigned int type,
			unsigned int code, int value)
{
	struct tsdev *tsdev = handle->private;
	struct tsdev_client *client;
	struct timeval time;

	switch (type) {
	case EV_ABS:
		switch (code) {
		case ABS_X:
			tsdev->x = value;
			break;

		case ABS_Y:
			tsdev->y = value;
			break;

		case ABS_PRESSURE:
			if (value > handle->dev->absmax[ABS_PRESSURE])
				value = handle->dev->absmax[ABS_PRESSURE];
			value -= handle->dev->absmin[ABS_PRESSURE];
			if (value < 0)
				value = 0;
			tsdev->pressure = value;
			break;
		}
		break;

	case EV_REL:
		switch (code) {
		case REL_X:
			tsdev->x += value;
			if (tsdev->x < 0)
				tsdev->x = 0;
			else if (tsdev->x > xres)
				tsdev->x = xres;
			break;

		case REL_Y:
			tsdev->y += value;
			if (tsdev->y < 0)
				tsdev->y = 0;
			else if (tsdev->y > yres)
				tsdev->y = yres;
			break;
		}
		break;

	case EV_KEY:
		if (code == BTN_TOUCH || code == BTN_MOUSE) {
			switch (value) {
			case 0:
				tsdev->pressure = 0;
				break;

			case 1:
				if (!tsdev->pressure)
					tsdev->pressure = 1;
				break;
			}
		}
		break;
	}

	if (type != EV_SYN || code != SYN_REPORT)
		return;

	list_for_each_entry(client, &tsdev->client_list, node) {
		int x, y, tmp;

		do_gettimeofday(&time);
		client->event[client->head].millisecs = time.tv_usec / 100;
		client->event[client->head].pressure = tsdev->pressure;

		x = tsdev->x;
		y = tsdev->y;

		/* Calibration */
		if (!client->raw) {
			x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
			y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
			if (tsdev->cal.xyswap) {
				tmp = x; x = y; y = tmp;
			}
		}

		client->event[client->head].x = x;
		client->event[client->head].y = y;
		client->head = (client->head + 1) & (TSDEV_BUFFER_SIZE - 1);
		kill_fasync(&client->fasync, SIGIO, POLL_IN);
	}
	wake_up_interruptible(&tsdev->wait);
}

static int tsdev_connect(struct input_handler *handler, struct input_dev *dev,
			 const struct input_device_id *id)
{
	struct tsdev *tsdev;
	struct class_device *cdev;
	dev_t devt;
	int minor, delta;
	int error;

	for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
	if (minor >= TSDEV_MINORS / 2) {
		printk(KERN_ERR
		       "tsdev: You have way too many touchscreens\n");
		return -ENFILE;
	}

	tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL);
	if (!tsdev)
		return -ENOMEM;

	INIT_LIST_HEAD(&tsdev->client_list);
	init_waitqueue_head(&tsdev->wait);

	sprintf(tsdev->name, "ts%d", minor);

	tsdev->exist = 1;
	tsdev->minor = minor;
	tsdev->handle.dev = dev;
	tsdev->handle.name = tsdev->name;
	tsdev->handle.handler = handler;
	tsdev->handle.private = tsdev;

	/* Precompute the rough calibration matrix */
	delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
	if (delta == 0)
		delta = 1;
	tsdev->cal.xscale = (xres << 8) / delta;
	tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);

	delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
	if (delta == 0)
		delta = 1;
	tsdev->cal.yscale = (yres << 8) / delta;
	tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);

	tsdev_table[minor] = tsdev;

	devt = MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),

	cdev = class_device_create(&input_class, &dev->cdev, devt,
				   dev->cdev.dev, tsdev->name);
	if (IS_ERR(cdev)) {
		error = PTR_ERR(cdev);
		goto err_free_tsdev;
	}

	/* temporary symlink to keep userspace happy */
	error = sysfs_create_link(&input_class.subsys.kobj,
				  &cdev->kobj, tsdev->name);
	if (error)
		goto err_cdev_destroy;

	error = input_register_handle(&tsdev->handle);
	if (error)
		goto err_remove_link;

	return 0;

 err_remove_link:
	sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
 err_cdev_destroy:
	class_device_destroy(&input_class, devt);
 err_free_tsdev:
	tsdev_table[minor] = NULL;
	kfree(tsdev);
	return error;
}

static void tsdev_disconnect(struct input_handle *handle)
{
	struct tsdev *tsdev = handle->private;
	struct tsdev_client *client;

	input_unregister_handle(handle);

	sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
	class_device_destroy(&input_class,
			MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
	tsdev->exist = 0;

	if (tsdev->open) {
		input_close_device(handle);
		wake_up_interruptible(&tsdev->wait);
		list_for_each_entry(client, &tsdev->client_list, node)
			kill_fasync(&client->fasync, SIGIO, POLL_HUP);
	} else
		tsdev_free(tsdev);
}

static const struct input_device_id tsdev_ids[] = {
	{
	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
	      .evbit	= { BIT(EV_KEY) | BIT(EV_REL) },
	      .keybit	= { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
	      .relbit	= { BIT(REL_X) | BIT(REL_Y) },
	}, /* A mouse like device, at least one button, two relative axes */

	{
	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
	      .evbit	= { BIT(EV_KEY) | BIT(EV_ABS) },
	      .keybit	= { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
	      .absbit	= { BIT(ABS_X) | BIT(ABS_Y) },
	}, /* A tablet like device, at least touch detection, two absolute axes */

	{
	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
	      .evbit	= { BIT(EV_ABS) },
	      .absbit	= { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
	}, /* A tablet like device with several gradations of pressure */

	{} /* Terminating entry */
};

MODULE_DEVICE_TABLE(input, tsdev_ids);

static struct input_handler tsdev_handler = {
	.event =	tsdev_event,
	.connect =	tsdev_connect,
	.disconnect =	tsdev_disconnect,
	.fops =		&tsdev_fops,
	.minor =	TSDEV_MINOR_BASE,
	.name =		"tsdev",
	.id_table =	tsdev_ids,
};

static int __init tsdev_init(void)
{
	return input_register_handler(&tsdev_handler);
}

static void __exit tsdev_exit(void)
{
	input_unregister_handler(&tsdev_handler);
}

module_init(tsdev_init);
module_exit(tsdev_exit);