1/*
2 * $Id: tsdev.c,v 1.1.1.1 2007/08/03 18:52:32 Exp $
3 *
4 *  Copyright (c) 2001 "Crazy" james Simmons
5 *
6 *  Compaq touchscreen protocol driver. The protocol emulated by this driver
7 *  is obsolete; for new programs use the tslib library which can read directly
8 *  from evdev and perform dejittering, variance filtering and calibration -
9 *  all in user space, not at kernel level. The meaning of this driver is
10 *  to allow usage of newer input drivers with old applications that use the
11 *  old /dev/h3600_ts and /dev/h3600_tsraw devices.
12 *
13 *  09-Apr-2004: Andrew Zabolotny <zap@homelink.ru>
14 *      Fixed to actually work, not just output random numbers.
15 *      Added support for both h3600_ts and h3600_tsraw protocol
16 *      emulation.
17 */
18
19/*
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
28 * GNU General Public License for more details.
29 *
30 * You should have received a copy of the GNU General Public License
31 * along with this program; if not, write to the Free Software
32 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 *
34 * Should you need to contact me, the author, you can do so either by
35 * e-mail - mail your message to <jsimmons@infradead.org>.
36 */
37
38#define TSDEV_MINOR_BASE	128
39#define TSDEV_MINORS		32
40/* First 16 devices are h3600_ts compatible; second 16 are h3600_tsraw */
41#define TSDEV_MINOR_MASK	15
42#define TSDEV_BUFFER_SIZE	64
43
44#include <linux/slab.h>
45#include <linux/poll.h>
46#include <linux/module.h>
47#include <linux/moduleparam.h>
48#include <linux/init.h>
49#include <linux/input.h>
50#include <linux/major.h>
51#include <linux/random.h>
52#include <linux/time.h>
53#include <linux/device.h>
54
55#ifndef CONFIG_INPUT_TSDEV_SCREEN_X
56#define CONFIG_INPUT_TSDEV_SCREEN_X	240
57#endif
58#ifndef CONFIG_INPUT_TSDEV_SCREEN_Y
59#define CONFIG_INPUT_TSDEV_SCREEN_Y	320
60#endif
61
62/* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
63 * devices. The first one must output X/Y data in 'cooked' format, e.g.
64 * filtered, dejittered and calibrated. Second device just outputs raw
65 * data received from the hardware.
66 *
67 * This driver doesn't support filtering and dejittering; it supports only
68 * calibration. Filtering and dejittering must be done in the low-level
69 * driver, if needed, because it may gain additional benefits from knowing
70 * the low-level details, the nature of noise and so on.
71 *
72 * The driver precomputes a calibration matrix given the initial xres and
73 * yres values (quite innacurate for most touchscreens) that will result
74 * in a more or less expected range of output values. The driver supports
75 * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
76 * new one, supposedly generated from the values taken from the raw device.
77 */
78
79MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
80MODULE_DESCRIPTION("Input driver to touchscreen converter");
81MODULE_LICENSE("GPL");
82
83static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
84module_param(xres, uint, 0);
85MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");
86
87static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
88module_param(yres, uint, 0);
89MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");
90
91/* From Compaq's Touch Screen Specification version 0.2 (draft) */
92struct ts_event {
93	short pressure;
94	short x;
95	short y;
96	short millisecs;
97};
98
99struct ts_calibration {
100	int xscale;
101	int xtrans;
102	int yscale;
103	int ytrans;
104	int xyswap;
105};
106
107struct tsdev {
108	int exist;
109	int open;
110	int minor;
111	char name[8];
112	wait_queue_head_t wait;
113	struct list_head client_list;
114	struct input_handle handle;
115	int x, y, pressure;
116	struct ts_calibration cal;
117};
118
119struct tsdev_client {
120	struct fasync_struct *fasync;
121	struct list_head node;
122	struct tsdev *tsdev;
123	int head, tail;
124	struct ts_event event[TSDEV_BUFFER_SIZE];
125	int raw;
126};
127
128/* The following ioctl codes are defined ONLY for backward compatibility.
129 * Don't use tsdev for new developement; use the tslib library instead.
130 * Touchscreen calibration is a fully userspace task.
131 */
132/* Use 'f' as magic number */
133#define IOC_H3600_TS_MAGIC  'f'
134#define TS_GET_CAL	_IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
135#define TS_SET_CAL	_IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)
136
137static struct tsdev *tsdev_table[TSDEV_MINORS/2];
138
139static int tsdev_fasync(int fd, struct file *file, int on)
140{
141	struct tsdev_client *client = file->private_data;
142	int retval;
143
144	retval = fasync_helper(fd, file, on, &client->fasync);
145	return retval < 0 ? retval : 0;
146}
147
148static int tsdev_open(struct inode *inode, struct file *file)
149{
150	int i = iminor(inode) - TSDEV_MINOR_BASE;
151	struct tsdev_client *client;
152	struct tsdev *tsdev;
153	int error;
154
155	printk(KERN_WARNING "tsdev (compaq touchscreen emulation) is scheduled "
156		"for removal.\nSee Documentation/feature-removal-schedule.txt "
157		"for details.\n");
158
159	if (i >= TSDEV_MINORS)
160		return -ENODEV;
161
162	tsdev = tsdev_table[i & TSDEV_MINOR_MASK];
163	if (!tsdev || !tsdev->exist)
164		return -ENODEV;
165
166	client = kzalloc(sizeof(struct tsdev_client), GFP_KERNEL);
167	if (!client)
168		return -ENOMEM;
169
170	client->tsdev = tsdev;
171	client->raw = (i >= TSDEV_MINORS / 2) ? 1 : 0;
172	list_add_tail(&client->node, &tsdev->client_list);
173
174	if (!tsdev->open++ && tsdev->exist) {
175		error = input_open_device(&tsdev->handle);
176		if (error) {
177			list_del(&client->node);
178			kfree(client);
179			return error;
180		}
181	}
182
183	file->private_data = client;
184	return 0;
185}
186
187static void tsdev_free(struct tsdev *tsdev)
188{
189	tsdev_table[tsdev->minor] = NULL;
190	kfree(tsdev);
191}
192
193static int tsdev_release(struct inode *inode, struct file *file)
194{
195	struct tsdev_client *client = file->private_data;
196	struct tsdev *tsdev = client->tsdev;
197
198	tsdev_fasync(-1, file, 0);
199
200	list_del(&client->node);
201	kfree(client);
202
203	if (!--tsdev->open) {
204		if (tsdev->exist)
205			input_close_device(&tsdev->handle);
206		else
207			tsdev_free(tsdev);
208	}
209
210	return 0;
211}
212
213static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
214			  loff_t *ppos)
215{
216	struct tsdev_client *client = file->private_data;
217	struct tsdev *tsdev = client->tsdev;
218	int retval = 0;
219
220	if (client->head == client->tail && tsdev->exist && (file->f_flags & O_NONBLOCK))
221		return -EAGAIN;
222
223	retval = wait_event_interruptible(tsdev->wait,
224			client->head != client->tail || !tsdev->exist);
225	if (retval)
226		return retval;
227
228	if (!tsdev->exist)
229		return -ENODEV;
230
231	while (client->head != client->tail &&
232	       retval + sizeof (struct ts_event) <= count) {
233		if (copy_to_user (buffer + retval, client->event + client->tail,
234				  sizeof (struct ts_event)))
235			return -EFAULT;
236		client->tail = (client->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
237		retval += sizeof (struct ts_event);
238	}
239
240	return retval;
241}
242
243/* No kernel lock - fine */
244static unsigned int tsdev_poll(struct file *file, poll_table *wait)
245{
246	struct tsdev_client *client = file->private_data;
247	struct tsdev *tsdev = client->tsdev;
248
249	poll_wait(file, &tsdev->wait, wait);
250	return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
251		(tsdev->exist ? 0 : (POLLHUP | POLLERR));
252}
253
254static int tsdev_ioctl(struct inode *inode, struct file *file,
255		       unsigned int cmd, unsigned long arg)
256{
257	struct tsdev_client *client = file->private_data;
258	struct tsdev *tsdev = client->tsdev;
259	int retval = 0;
260
261	switch (cmd) {
262	case TS_GET_CAL:
263		if (copy_to_user((void __user *)arg, &tsdev->cal,
264				 sizeof (struct ts_calibration)))
265			retval = -EFAULT;
266		break;
267
268	case TS_SET_CAL:
269		if (copy_from_user(&tsdev->cal, (void __user *)arg,
270				   sizeof (struct ts_calibration)))
271			retval = -EFAULT;
272		break;
273
274	default:
275		retval = -EINVAL;
276		break;
277	}
278
279	return retval;
280}
281
282static const struct file_operations tsdev_fops = {
283	.owner =	THIS_MODULE,
284	.open =		tsdev_open,
285	.release =	tsdev_release,
286	.read =		tsdev_read,
287	.poll =		tsdev_poll,
288	.fasync =	tsdev_fasync,
289	.ioctl =	tsdev_ioctl,
290};
291
292static void tsdev_event(struct input_handle *handle, unsigned int type,
293			unsigned int code, int value)
294{
295	struct tsdev *tsdev = handle->private;
296	struct tsdev_client *client;
297	struct timeval time;
298
299	switch (type) {
300	case EV_ABS:
301		switch (code) {
302		case ABS_X:
303			tsdev->x = value;
304			break;
305
306		case ABS_Y:
307			tsdev->y = value;
308			break;
309
310		case ABS_PRESSURE:
311			if (value > handle->dev->absmax[ABS_PRESSURE])
312				value = handle->dev->absmax[ABS_PRESSURE];
313			value -= handle->dev->absmin[ABS_PRESSURE];
314			if (value < 0)
315				value = 0;
316			tsdev->pressure = value;
317			break;
318		}
319		break;
320
321	case EV_REL:
322		switch (code) {
323		case REL_X:
324			tsdev->x += value;
325			if (tsdev->x < 0)
326				tsdev->x = 0;
327			else if (tsdev->x > xres)
328				tsdev->x = xres;
329			break;
330
331		case REL_Y:
332			tsdev->y += value;
333			if (tsdev->y < 0)
334				tsdev->y = 0;
335			else if (tsdev->y > yres)
336				tsdev->y = yres;
337			break;
338		}
339		break;
340
341	case EV_KEY:
342		if (code == BTN_TOUCH || code == BTN_MOUSE) {
343			switch (value) {
344			case 0:
345				tsdev->pressure = 0;
346				break;
347
348			case 1:
349				if (!tsdev->pressure)
350					tsdev->pressure = 1;
351				break;
352			}
353		}
354		break;
355	}
356
357	if (type != EV_SYN || code != SYN_REPORT)
358		return;
359
360	list_for_each_entry(client, &tsdev->client_list, node) {
361		int x, y, tmp;
362
363		do_gettimeofday(&time);
364		client->event[client->head].millisecs = time.tv_usec / 100;
365		client->event[client->head].pressure = tsdev->pressure;
366
367		x = tsdev->x;
368		y = tsdev->y;
369
370		/* Calibration */
371		if (!client->raw) {
372			x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
373			y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
374			if (tsdev->cal.xyswap) {
375				tmp = x; x = y; y = tmp;
376			}
377		}
378
379		client->event[client->head].x = x;
380		client->event[client->head].y = y;
381		client->head = (client->head + 1) & (TSDEV_BUFFER_SIZE - 1);
382		kill_fasync(&client->fasync, SIGIO, POLL_IN);
383	}
384	wake_up_interruptible(&tsdev->wait);
385}
386
387static int tsdev_connect(struct input_handler *handler, struct input_dev *dev,
388			 const struct input_device_id *id)
389{
390	struct tsdev *tsdev;
391	struct class_device *cdev;
392	dev_t devt;
393	int minor, delta;
394	int error;
395
396	for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
397	if (minor >= TSDEV_MINORS / 2) {
398		printk(KERN_ERR
399		       "tsdev: You have way too many touchscreens\n");
400		return -ENFILE;
401	}
402
403	tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL);
404	if (!tsdev)
405		return -ENOMEM;
406
407	INIT_LIST_HEAD(&tsdev->client_list);
408	init_waitqueue_head(&tsdev->wait);
409
410	sprintf(tsdev->name, "ts%d", minor);
411
412	tsdev->exist = 1;
413	tsdev->minor = minor;
414	tsdev->handle.dev = dev;
415	tsdev->handle.name = tsdev->name;
416	tsdev->handle.handler = handler;
417	tsdev->handle.private = tsdev;
418
419	/* Precompute the rough calibration matrix */
420	delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
421	if (delta == 0)
422		delta = 1;
423	tsdev->cal.xscale = (xres << 8) / delta;
424	tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
425
426	delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
427	if (delta == 0)
428		delta = 1;
429	tsdev->cal.yscale = (yres << 8) / delta;
430	tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
431
432	tsdev_table[minor] = tsdev;
433
434	devt = MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
435
436	cdev = class_device_create(&input_class, &dev->cdev, devt,
437				   dev->cdev.dev, tsdev->name);
438	if (IS_ERR(cdev)) {
439		error = PTR_ERR(cdev);
440		goto err_free_tsdev;
441	}
442
443	/* temporary symlink to keep userspace happy */
444	error = sysfs_create_link(&input_class.subsys.kobj,
445				  &cdev->kobj, tsdev->name);
446	if (error)
447		goto err_cdev_destroy;
448
449	error = input_register_handle(&tsdev->handle);
450	if (error)
451		goto err_remove_link;
452
453	return 0;
454
455 err_remove_link:
456	sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
457 err_cdev_destroy:
458	class_device_destroy(&input_class, devt);
459 err_free_tsdev:
460	tsdev_table[minor] = NULL;
461	kfree(tsdev);
462	return error;
463}
464
465static void tsdev_disconnect(struct input_handle *handle)
466{
467	struct tsdev *tsdev = handle->private;
468	struct tsdev_client *client;
469
470	input_unregister_handle(handle);
471
472	sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
473	class_device_destroy(&input_class,
474			MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
475	tsdev->exist = 0;
476
477	if (tsdev->open) {
478		input_close_device(handle);
479		list_for_each_entry(client, &tsdev->client_list, node)
480			kill_fasync(&client->fasync, SIGIO, POLL_HUP);
481		wake_up_interruptible(&tsdev->wait);
482	} else
483		tsdev_free(tsdev);
484}
485
486static const struct input_device_id tsdev_ids[] = {
487	{
488	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
489	      .evbit	= { BIT(EV_KEY) | BIT(EV_REL) },
490	      .keybit	= { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
491	      .relbit	= { BIT(REL_X) | BIT(REL_Y) },
492	}, /* A mouse like device, at least one button, two relative axes */
493
494	{
495	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
496	      .evbit	= { BIT(EV_KEY) | BIT(EV_ABS) },
497	      .keybit	= { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
498	      .absbit	= { BIT(ABS_X) | BIT(ABS_Y) },
499	}, /* A tablet like device, at least touch detection, two absolute axes */
500
501	{
502	      .flags	= INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
503	      .evbit	= { BIT(EV_ABS) },
504	      .absbit	= { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
505	}, /* A tablet like device with several gradations of pressure */
506
507	{} /* Terminating entry */
508};
509
510MODULE_DEVICE_TABLE(input, tsdev_ids);
511
512static struct input_handler tsdev_handler = {
513	.event =	tsdev_event,
514	.connect =	tsdev_connect,
515	.disconnect =	tsdev_disconnect,
516	.fops =		&tsdev_fops,
517	.minor =	TSDEV_MINOR_BASE,
518	.name =		"tsdev",
519	.id_table =	tsdev_ids,
520};
521
522static int __init tsdev_init(void)
523{
524	return input_register_handler(&tsdev_handler);
525}
526
527static void __exit tsdev_exit(void)
528{
529	input_unregister_handler(&tsdev_handler);
530}
531
532module_init(tsdev_init);
533module_exit(tsdev_exit);
534