summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/ad7879.c
blob: e2482b40da5198fdb1406e135fff827d049e5895 (plain)
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
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
/*
 * AD7879/AD7889 based touchscreen and GPIO driver
 *
 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 *
 * History:
 * Copyright (c) 2005 David Brownell
 * Copyright (c) 2006 Nokia Corporation
 * Various changes: Imre Deak <imre.deak@nokia.com>
 *
 * Using code from:
 *  - corgi_ts.c
 *	Copyright (C) 2004-2005 Richard Purdie
 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 *	Copyright (C) 2002 MontaVista Software
 *	Copyright (C) 2004 Texas Instruments
 *	Copyright (C) 2005 Dirk Behme
 *  - ad7877.c
 *	Copyright (C) 2006-2008 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/gpio.h>

#include <linux/spi/ad7879.h>
#include <linux/module.h>
#include "ad7879.h"

#define AD7879_REG_ZEROS		0
#define AD7879_REG_CTRL1		1
#define AD7879_REG_CTRL2		2
#define AD7879_REG_CTRL3		3
#define AD7879_REG_AUX1HIGH		4
#define AD7879_REG_AUX1LOW		5
#define AD7879_REG_TEMP1HIGH		6
#define AD7879_REG_TEMP1LOW		7
#define AD7879_REG_XPLUS		8
#define AD7879_REG_YPLUS		9
#define AD7879_REG_Z1			10
#define AD7879_REG_Z2			11
#define AD7879_REG_AUXVBAT		12
#define AD7879_REG_TEMP			13
#define AD7879_REG_REVID		14

/* Control REG 1 */
#define AD7879_TMR(x)			((x & 0xFF) << 0)
#define AD7879_ACQ(x)			((x & 0x3) << 8)
#define AD7879_MODE_NOC			(0 << 10)	/* Do not convert */
#define AD7879_MODE_SCC			(1 << 10)	/* Single channel conversion */
#define AD7879_MODE_SEQ0		(2 << 10)	/* Sequence 0 in Slave Mode */
#define AD7879_MODE_SEQ1		(3 << 10)	/* Sequence 1 in Master Mode */
#define AD7879_MODE_INT			(1 << 15)	/* PENIRQ disabled INT enabled */

/* Control REG 2 */
#define AD7879_FCD(x)			((x & 0x3) << 0)
#define AD7879_RESET			(1 << 4)
#define AD7879_MFS(x)			((x & 0x3) << 5)
#define AD7879_AVG(x)			((x & 0x3) << 7)
#define	AD7879_SER			(1 << 9)	/* non-differential */
#define	AD7879_DFR			(0 << 9)	/* differential */
#define AD7879_GPIOPOL			(1 << 10)
#define AD7879_GPIODIR			(1 << 11)
#define AD7879_GPIO_DATA		(1 << 12)
#define AD7879_GPIO_EN			(1 << 13)
#define AD7879_PM(x)			((x & 0x3) << 14)
#define AD7879_PM_SHUTDOWN		(0)
#define AD7879_PM_DYN			(1)
#define AD7879_PM_FULLON		(2)

/* Control REG 3 */
#define AD7879_TEMPMASK_BIT		(1<<15)
#define AD7879_AUXVBATMASK_BIT		(1<<14)
#define AD7879_INTMODE_BIT		(1<<13)
#define AD7879_GPIOALERTMASK_BIT	(1<<12)
#define AD7879_AUXLOW_BIT		(1<<11)
#define AD7879_AUXHIGH_BIT		(1<<10)
#define AD7879_TEMPLOW_BIT		(1<<9)
#define AD7879_TEMPHIGH_BIT		(1<<8)
#define AD7879_YPLUS_BIT		(1<<7)
#define AD7879_XPLUS_BIT		(1<<6)
#define AD7879_Z1_BIT			(1<<5)
#define AD7879_Z2_BIT			(1<<4)
#define AD7879_AUX_BIT			(1<<3)
#define AD7879_VBAT_BIT			(1<<2)
#define AD7879_TEMP_BIT			(1<<1)

enum {
	AD7879_SEQ_XPOS  = 0,
	AD7879_SEQ_YPOS  = 1,
	AD7879_SEQ_Z1    = 2,
	AD7879_SEQ_Z2    = 3,
	AD7879_NR_SENSE  = 4,
};

#define	MAX_12BIT			((1<<12)-1)
#define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)

struct ad7879 {
	const struct ad7879_bus_ops *bops;

	struct device		*dev;
	struct input_dev	*input;
	struct timer_list	timer;
#ifdef CONFIG_GPIOLIB
	struct gpio_chip	gc;
	struct mutex		mutex;
#endif
	unsigned int		irq;
	bool			disabled;	/* P: input->mutex */
	bool			suspended;	/* P: input->mutex */
	u16			conversion_data[AD7879_NR_SENSE];
	char			phys[32];
	u8			first_conversion_delay;
	u8			acquisition_time;
	u8			averaging;
	u8			pen_down_acc_interval;
	u8			median;
	u16			x_plate_ohms;
	u16			pressure_max;
	u16			cmd_crtl1;
	u16			cmd_crtl2;
	u16			cmd_crtl3;
	int			x;
	int			y;
	int			Rt;
};

static int ad7879_read(struct ad7879 *ts, u8 reg)
{
	return ts->bops->read(ts->dev, reg);
}

static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
{
	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
}

static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
{
	return ts->bops->write(ts->dev, reg, val);
}

static int ad7879_report(struct ad7879 *ts)
{
	struct input_dev *input_dev = ts->input;
	unsigned Rt;
	u16 x, y, z1, z2;

	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;

	/*
	 * The samples processed here are already preprocessed by the AD7879.
	 * The preprocessing function consists of a median and an averaging
	 * filter.  The combination of these two techniques provides a robust
	 * solution, discarding the spurious noise in the signal and keeping
	 * only the data of interest.  The size of both filters is
	 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
	 * user-programmable conversion controls include variable acquisition
	 * time, and first conversion delay. Up to 16 averages can be taken
	 * per conversion.
	 */

	if (likely(x && z1)) {
		/* compute touch pressure resistance using equation #1 */
		Rt = (z2 - z1) * x * ts->x_plate_ohms;
		Rt /= z1;
		Rt = (Rt + 2047) >> 12;

		/*
		 * Sample found inconsistent, pressure is beyond
		 * the maximum. Don't report it to user space.
		 */
		if (Rt > ts->pressure_max)
			return -EINVAL;

		/*
		 * Note that we delay reporting events by one sample.
		 * This is done to avoid reporting last sample of the
		 * touch sequence, which may be incomplete if finger
		 * leaves the surface before last reading is taken.
		 */
		if (timer_pending(&ts->timer)) {
			/* Touch continues */
			input_report_key(input_dev, BTN_TOUCH, 1);
			input_report_abs(input_dev, ABS_X, ts->x);
			input_report_abs(input_dev, ABS_Y, ts->y);
			input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
			input_sync(input_dev);
		}

		ts->x = x;
		ts->y = y;
		ts->Rt = Rt;

		return 0;
	}

	return -EINVAL;
}

static void ad7879_ts_event_release(struct ad7879 *ts)
{
	struct input_dev *input_dev = ts->input;

	input_report_abs(input_dev, ABS_PRESSURE, 0);
	input_report_key(input_dev, BTN_TOUCH, 0);
	input_sync(input_dev);
}

static void ad7879_timer(unsigned long handle)
{
	struct ad7879 *ts = (void *)handle;

	ad7879_ts_event_release(ts);
}

static irqreturn_t ad7879_irq(int irq, void *handle)
{
	struct ad7879 *ts = handle;

	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);

	if (!ad7879_report(ts))
		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);

	return IRQ_HANDLED;
}

static void __ad7879_enable(struct ad7879 *ts)
{
	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);

	enable_irq(ts->irq);
}

static void __ad7879_disable(struct ad7879 *ts)
{
	u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
		AD7879_PM(AD7879_PM_SHUTDOWN);
	disable_irq(ts->irq);

	if (del_timer_sync(&ts->timer))
		ad7879_ts_event_release(ts);

	ad7879_write(ts, AD7879_REG_CTRL2, reg);
}


static int ad7879_open(struct input_dev *input)
{
	struct ad7879 *ts = input_get_drvdata(input);

	/* protected by input->mutex */
	if (!ts->disabled && !ts->suspended)
		__ad7879_enable(ts);

	return 0;
}

static void ad7879_close(struct input_dev* input)
{
	struct ad7879 *ts = input_get_drvdata(input);

	/* protected by input->mutex */
	if (!ts->disabled && !ts->suspended)
		__ad7879_disable(ts);
}

#ifdef CONFIG_PM_SLEEP
static int ad7879_suspend(struct device *dev)
{
	struct ad7879 *ts = dev_get_drvdata(dev);

	mutex_lock(&ts->input->mutex);

	if (!ts->suspended && !ts->disabled && ts->input->users)
		__ad7879_disable(ts);

	ts->suspended = true;

	mutex_unlock(&ts->input->mutex);

	return 0;
}

static int ad7879_resume(struct device *dev)
{
	struct ad7879 *ts = dev_get_drvdata(dev);

	mutex_lock(&ts->input->mutex);

	if (ts->suspended && !ts->disabled && ts->input->users)
		__ad7879_enable(ts);

	ts->suspended = false;

	mutex_unlock(&ts->input->mutex);

	return 0;
}
#endif

SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
EXPORT_SYMBOL(ad7879_pm_ops);

static void ad7879_toggle(struct ad7879 *ts, bool disable)
{
	mutex_lock(&ts->input->mutex);

	if (!ts->suspended && ts->input->users != 0) {

		if (disable) {
			if (ts->disabled)
				__ad7879_enable(ts);
		} else {
			if (!ts->disabled)
				__ad7879_disable(ts);
		}
	}

	ts->disabled = disable;

	mutex_unlock(&ts->input->mutex);
}

static ssize_t ad7879_disable_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct ad7879 *ts = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", ts->disabled);
}

static ssize_t ad7879_disable_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct ad7879 *ts = dev_get_drvdata(dev);
	unsigned int val;
	int error;

	error = kstrtouint(buf, 10, &val);
	if (error)
		return error;

	ad7879_toggle(ts, val);

	return count;
}

static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);

static struct attribute *ad7879_attributes[] = {
	&dev_attr_disable.attr,
	NULL
};

static const struct attribute_group ad7879_attr_group = {
	.attrs = ad7879_attributes,
};

#ifdef CONFIG_GPIOLIB
static int ad7879_gpio_direction_input(struct gpio_chip *chip,
					unsigned gpio)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	int err;

	mutex_lock(&ts->mutex);
	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);

	return err;
}

static int ad7879_gpio_direction_output(struct gpio_chip *chip,
					unsigned gpio, int level)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	int err;

	mutex_lock(&ts->mutex);
	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
	if (level)
		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
	else
		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);

	return err;
}

static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	u16 val;

	mutex_lock(&ts->mutex);
	val = ad7879_read(ts, AD7879_REG_CTRL2);
	mutex_unlock(&ts->mutex);

	return !!(val & AD7879_GPIO_DATA);
}

static void ad7879_gpio_set_value(struct gpio_chip *chip,
				  unsigned gpio, int value)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);

	mutex_lock(&ts->mutex);
	if (value)
		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
	else
		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);
}

static int ad7879_gpio_add(struct ad7879 *ts,
			   const struct ad7879_platform_data *pdata)
{
	int ret = 0;

	mutex_init(&ts->mutex);

	if (pdata->gpio_export) {
		ts->gc.direction_input = ad7879_gpio_direction_input;
		ts->gc.direction_output = ad7879_gpio_direction_output;
		ts->gc.get = ad7879_gpio_get_value;
		ts->gc.set = ad7879_gpio_set_value;
		ts->gc.can_sleep = 1;
		ts->gc.base = pdata->gpio_base;
		ts->gc.ngpio = 1;
		ts->gc.label = "AD7879-GPIO";
		ts->gc.owner = THIS_MODULE;
		ts->gc.dev = ts->dev;

		ret = gpiochip_add(&ts->gc);
		if (ret)
			dev_err(ts->dev, "failed to register gpio %d\n",
				ts->gc.base);
	}

	return ret;
}

static void ad7879_gpio_remove(struct ad7879 *ts)
{
	const struct ad7879_platform_data *pdata = ts->dev->platform_data;
	int ret;

	if (pdata->gpio_export) {
		ret = gpiochip_remove(&ts->gc);
		if (ret)
			dev_err(ts->dev, "failed to remove gpio %d\n",
				ts->gc.base);
	}
}
#else
static inline int ad7879_gpio_add(struct ad7879 *ts,
				  const struct ad7879_platform_data *pdata)
{
	return 0;
}

static inline void ad7879_gpio_remove(struct ad7879 *ts)
{
}
#endif

struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
			    const struct ad7879_bus_ops *bops)
{
	struct ad7879_platform_data *pdata = dev->platform_data;
	struct ad7879 *ts;
	struct input_dev *input_dev;
	int err;
	u16 revid;

	if (!irq) {
		dev_err(dev, "no IRQ?\n");
		err = -EINVAL;
		goto err_out;
	}

	if (!pdata) {
		dev_err(dev, "no platform data?\n");
		err = -EINVAL;
		goto err_out;
	}

	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts || !input_dev) {
		err = -ENOMEM;
		goto err_free_mem;
	}

	ts->bops = bops;
	ts->dev = dev;
	ts->input = input_dev;
	ts->irq = irq;

	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);

	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
	ts->pressure_max = pdata->pressure_max ? : ~0;

	ts->first_conversion_delay = pdata->first_conversion_delay;
	ts->acquisition_time = pdata->acquisition_time;
	ts->averaging = pdata->averaging;
	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
	ts->median = pdata->median;

	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));

	input_dev->name = "AD7879 Touchscreen";
	input_dev->phys = ts->phys;
	input_dev->dev.parent = dev;
	input_dev->id.bustype = bops->bustype;

	input_dev->open = ad7879_open;
	input_dev->close = ad7879_close;

	input_set_drvdata(input_dev, ts);

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(ABS_X, input_dev->absbit);
	__set_bit(ABS_Y, input_dev->absbit);
	__set_bit(ABS_PRESSURE, input_dev->absbit);

	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);

	input_set_abs_params(input_dev, ABS_X,
			pdata->x_min ? : 0,
			pdata->x_max ? : MAX_12BIT,
			0, 0);
	input_set_abs_params(input_dev, ABS_Y,
			pdata->y_min ? : 0,
			pdata->y_max ? : MAX_12BIT,
			0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE,
			pdata->pressure_min, pdata->pressure_max, 0, 0);

	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
	if (err < 0) {
		dev_err(dev, "Failed to write %s\n", input_dev->name);
		goto err_free_mem;
	}

	revid = ad7879_read(ts, AD7879_REG_REVID);
	input_dev->id.product = (revid & 0xff);
	input_dev->id.version = revid >> 8;
	if (input_dev->id.product != devid) {
		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
			input_dev->name, devid, revid);
		err = -ENODEV;
		goto err_free_mem;
	}

	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
			AD7879_XPLUS_BIT |
			AD7879_Z2_BIT |
			AD7879_Z1_BIT |
			AD7879_TEMPMASK_BIT |
			AD7879_AUXVBATMASK_BIT |
			AD7879_GPIOALERTMASK_BIT;

	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
			AD7879_AVG(ts->averaging) |
			AD7879_MFS(ts->median) |
			AD7879_FCD(ts->first_conversion_delay);

	ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
			AD7879_ACQ(ts->acquisition_time) |
			AD7879_TMR(ts->pen_down_acc_interval);

	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
				   IRQF_TRIGGER_FALLING,
				   dev_name(dev), ts);
	if (err) {
		dev_err(dev, "irq %d busy?\n", ts->irq);
		goto err_free_mem;
	}

	__ad7879_disable(ts);

	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
	if (err)
		goto err_free_irq;

	err = ad7879_gpio_add(ts, pdata);
	if (err)
		goto err_remove_attr;

	err = input_register_device(input_dev);
	if (err)
		goto err_remove_gpio;

	return ts;

err_remove_gpio:
	ad7879_gpio_remove(ts);
err_remove_attr:
	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
err_free_irq:
	free_irq(ts->irq, ts);
err_free_mem:
	input_free_device(input_dev);
	kfree(ts);
err_out:
	return ERR_PTR(err);
}
EXPORT_SYMBOL(ad7879_probe);

void ad7879_remove(struct ad7879 *ts)
{
	ad7879_gpio_remove(ts);
	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
	free_irq(ts->irq, ts);
	input_unregister_device(ts->input);
	kfree(ts);
}
EXPORT_SYMBOL(ad7879_remove);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
MODULE_LICENSE("GPL");