1 /*
2  * AD7879/AD7889 based touchscreen and GPIO driver
3  *
4  * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  *
8  * History:
9  * Copyright (c) 2005 David Brownell
10  * Copyright (c) 2006 Nokia Corporation
11  * Various changes: Imre Deak <imre.deak@nokia.com>
12  *
13  * Using code from:
14  *  - corgi_ts.c
15  *	Copyright (C) 2004-2005 Richard Purdie
16  *  - omap_ts.[hc], ads7846.h, ts_osk.c
17  *	Copyright (C) 2002 MontaVista Software
18  *	Copyright (C) 2004 Texas Instruments
19  *	Copyright (C) 2005 Dirk Behme
20  *  - ad7877.c
21  *	Copyright (C) 2006-2008 Analog Devices Inc.
22  */
23 
24 #include <linux/device.h>
25 #include <linux/delay.h>
26 #include <linux/input.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h>
29 #include <linux/slab.h>
30 #include <linux/spi/spi.h>
31 #include <linux/i2c.h>
32 #include <linux/gpio.h>
33 
34 #include <linux/input/touchscreen.h>
35 #include <linux/platform_data/ad7879.h>
36 #include <linux/module.h>
37 #include "ad7879.h"
38 
39 #define AD7879_REG_ZEROS		0
40 #define AD7879_REG_CTRL1		1
41 #define AD7879_REG_CTRL2		2
42 #define AD7879_REG_CTRL3		3
43 #define AD7879_REG_AUX1HIGH		4
44 #define AD7879_REG_AUX1LOW		5
45 #define AD7879_REG_TEMP1HIGH		6
46 #define AD7879_REG_TEMP1LOW		7
47 #define AD7879_REG_XPLUS		8
48 #define AD7879_REG_YPLUS		9
49 #define AD7879_REG_Z1			10
50 #define AD7879_REG_Z2			11
51 #define AD7879_REG_AUXVBAT		12
52 #define AD7879_REG_TEMP			13
53 #define AD7879_REG_REVID		14
54 
55 /* Control REG 1 */
56 #define AD7879_TMR(x)			((x & 0xFF) << 0)
57 #define AD7879_ACQ(x)			((x & 0x3) << 8)
58 #define AD7879_MODE_NOC			(0 << 10)	/* Do not convert */
59 #define AD7879_MODE_SCC			(1 << 10)	/* Single channel conversion */
60 #define AD7879_MODE_SEQ0		(2 << 10)	/* Sequence 0 in Slave Mode */
61 #define AD7879_MODE_SEQ1		(3 << 10)	/* Sequence 1 in Master Mode */
62 #define AD7879_MODE_INT			(1 << 15)	/* PENIRQ disabled INT enabled */
63 
64 /* Control REG 2 */
65 #define AD7879_FCD(x)			((x & 0x3) << 0)
66 #define AD7879_RESET			(1 << 4)
67 #define AD7879_MFS(x)			((x & 0x3) << 5)
68 #define AD7879_AVG(x)			((x & 0x3) << 7)
69 #define	AD7879_SER			(1 << 9)	/* non-differential */
70 #define	AD7879_DFR			(0 << 9)	/* differential */
71 #define AD7879_GPIOPOL			(1 << 10)
72 #define AD7879_GPIODIR			(1 << 11)
73 #define AD7879_GPIO_DATA		(1 << 12)
74 #define AD7879_GPIO_EN			(1 << 13)
75 #define AD7879_PM(x)			((x & 0x3) << 14)
76 #define AD7879_PM_SHUTDOWN		(0)
77 #define AD7879_PM_DYN			(1)
78 #define AD7879_PM_FULLON		(2)
79 
80 /* Control REG 3 */
81 #define AD7879_TEMPMASK_BIT		(1<<15)
82 #define AD7879_AUXVBATMASK_BIT		(1<<14)
83 #define AD7879_INTMODE_BIT		(1<<13)
84 #define AD7879_GPIOALERTMASK_BIT	(1<<12)
85 #define AD7879_AUXLOW_BIT		(1<<11)
86 #define AD7879_AUXHIGH_BIT		(1<<10)
87 #define AD7879_TEMPLOW_BIT		(1<<9)
88 #define AD7879_TEMPHIGH_BIT		(1<<8)
89 #define AD7879_YPLUS_BIT		(1<<7)
90 #define AD7879_XPLUS_BIT		(1<<6)
91 #define AD7879_Z1_BIT			(1<<5)
92 #define AD7879_Z2_BIT			(1<<4)
93 #define AD7879_AUX_BIT			(1<<3)
94 #define AD7879_VBAT_BIT			(1<<2)
95 #define AD7879_TEMP_BIT			(1<<1)
96 
97 enum {
98 	AD7879_SEQ_YPOS  = 0,
99 	AD7879_SEQ_XPOS  = 1,
100 	AD7879_SEQ_Z1    = 2,
101 	AD7879_SEQ_Z2    = 3,
102 	AD7879_NR_SENSE  = 4,
103 };
104 
105 #define	MAX_12BIT			((1<<12)-1)
106 #define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)
107 
108 struct ad7879 {
109 	const struct ad7879_bus_ops *bops;
110 
111 	struct device		*dev;
112 	struct input_dev	*input;
113 	struct timer_list	timer;
114 #ifdef CONFIG_GPIOLIB
115 	struct gpio_chip	gc;
116 	struct mutex		mutex;
117 #endif
118 	unsigned int		irq;
119 	bool			disabled;	/* P: input->mutex */
120 	bool			suspended;	/* P: input->mutex */
121 	bool			swap_xy;
122 	u16			conversion_data[AD7879_NR_SENSE];
123 	char			phys[32];
124 	u8			first_conversion_delay;
125 	u8			acquisition_time;
126 	u8			averaging;
127 	u8			pen_down_acc_interval;
128 	u8			median;
129 	u16			x_plate_ohms;
130 	u16			cmd_crtl1;
131 	u16			cmd_crtl2;
132 	u16			cmd_crtl3;
133 	int			x;
134 	int			y;
135 	int			Rt;
136 };
137 
138 static int ad7879_read(struct ad7879 *ts, u8 reg)
139 {
140 	return ts->bops->read(ts->dev, reg);
141 }
142 
143 static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
144 {
145 	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
146 }
147 
148 static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
149 {
150 	return ts->bops->write(ts->dev, reg, val);
151 }
152 
153 static int ad7879_report(struct ad7879 *ts)
154 {
155 	struct input_dev *input_dev = ts->input;
156 	unsigned Rt;
157 	u16 x, y, z1, z2;
158 
159 	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
160 	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
161 	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
162 	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
163 
164 	if (ts->swap_xy)
165 		swap(x, y);
166 
167 	/*
168 	 * The samples processed here are already preprocessed by the AD7879.
169 	 * The preprocessing function consists of a median and an averaging
170 	 * filter.  The combination of these two techniques provides a robust
171 	 * solution, discarding the spurious noise in the signal and keeping
172 	 * only the data of interest.  The size of both filters is
173 	 * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
174 	 * Other user-programmable conversion controls include variable
175 	 * acquisition time, and first conversion delay. Up to 16 averages can
176 	 * be taken per conversion.
177 	 */
178 
179 	if (likely(x && z1)) {
180 		/* compute touch pressure resistance using equation #1 */
181 		Rt = (z2 - z1) * x * ts->x_plate_ohms;
182 		Rt /= z1;
183 		Rt = (Rt + 2047) >> 12;
184 
185 		/*
186 		 * Sample found inconsistent, pressure is beyond
187 		 * the maximum. Don't report it to user space.
188 		 */
189 		if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
190 			return -EINVAL;
191 
192 		/*
193 		 * Note that we delay reporting events by one sample.
194 		 * This is done to avoid reporting last sample of the
195 		 * touch sequence, which may be incomplete if finger
196 		 * leaves the surface before last reading is taken.
197 		 */
198 		if (timer_pending(&ts->timer)) {
199 			/* Touch continues */
200 			input_report_key(input_dev, BTN_TOUCH, 1);
201 			input_report_abs(input_dev, ABS_X, ts->x);
202 			input_report_abs(input_dev, ABS_Y, ts->y);
203 			input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
204 			input_sync(input_dev);
205 		}
206 
207 		ts->x = x;
208 		ts->y = y;
209 		ts->Rt = Rt;
210 
211 		return 0;
212 	}
213 
214 	return -EINVAL;
215 }
216 
217 static void ad7879_ts_event_release(struct ad7879 *ts)
218 {
219 	struct input_dev *input_dev = ts->input;
220 
221 	input_report_abs(input_dev, ABS_PRESSURE, 0);
222 	input_report_key(input_dev, BTN_TOUCH, 0);
223 	input_sync(input_dev);
224 }
225 
226 static void ad7879_timer(unsigned long handle)
227 {
228 	struct ad7879 *ts = (void *)handle;
229 
230 	ad7879_ts_event_release(ts);
231 }
232 
233 static irqreturn_t ad7879_irq(int irq, void *handle)
234 {
235 	struct ad7879 *ts = handle;
236 
237 	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
238 
239 	if (!ad7879_report(ts))
240 		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
241 
242 	return IRQ_HANDLED;
243 }
244 
245 static void __ad7879_enable(struct ad7879 *ts)
246 {
247 	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
248 	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
249 	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
250 
251 	enable_irq(ts->irq);
252 }
253 
254 static void __ad7879_disable(struct ad7879 *ts)
255 {
256 	u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
257 		AD7879_PM(AD7879_PM_SHUTDOWN);
258 	disable_irq(ts->irq);
259 
260 	if (del_timer_sync(&ts->timer))
261 		ad7879_ts_event_release(ts);
262 
263 	ad7879_write(ts, AD7879_REG_CTRL2, reg);
264 }
265 
266 
267 static int ad7879_open(struct input_dev *input)
268 {
269 	struct ad7879 *ts = input_get_drvdata(input);
270 
271 	/* protected by input->mutex */
272 	if (!ts->disabled && !ts->suspended)
273 		__ad7879_enable(ts);
274 
275 	return 0;
276 }
277 
278 static void ad7879_close(struct input_dev* input)
279 {
280 	struct ad7879 *ts = input_get_drvdata(input);
281 
282 	/* protected by input->mutex */
283 	if (!ts->disabled && !ts->suspended)
284 		__ad7879_disable(ts);
285 }
286 
287 static int __maybe_unused ad7879_suspend(struct device *dev)
288 {
289 	struct ad7879 *ts = dev_get_drvdata(dev);
290 
291 	mutex_lock(&ts->input->mutex);
292 
293 	if (!ts->suspended && !ts->disabled && ts->input->users)
294 		__ad7879_disable(ts);
295 
296 	ts->suspended = true;
297 
298 	mutex_unlock(&ts->input->mutex);
299 
300 	return 0;
301 }
302 
303 static int __maybe_unused ad7879_resume(struct device *dev)
304 {
305 	struct ad7879 *ts = dev_get_drvdata(dev);
306 
307 	mutex_lock(&ts->input->mutex);
308 
309 	if (ts->suspended && !ts->disabled && ts->input->users)
310 		__ad7879_enable(ts);
311 
312 	ts->suspended = false;
313 
314 	mutex_unlock(&ts->input->mutex);
315 
316 	return 0;
317 }
318 
319 SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
320 EXPORT_SYMBOL(ad7879_pm_ops);
321 
322 static void ad7879_toggle(struct ad7879 *ts, bool disable)
323 {
324 	mutex_lock(&ts->input->mutex);
325 
326 	if (!ts->suspended && ts->input->users != 0) {
327 
328 		if (disable) {
329 			if (ts->disabled)
330 				__ad7879_enable(ts);
331 		} else {
332 			if (!ts->disabled)
333 				__ad7879_disable(ts);
334 		}
335 	}
336 
337 	ts->disabled = disable;
338 
339 	mutex_unlock(&ts->input->mutex);
340 }
341 
342 static ssize_t ad7879_disable_show(struct device *dev,
343 				     struct device_attribute *attr, char *buf)
344 {
345 	struct ad7879 *ts = dev_get_drvdata(dev);
346 
347 	return sprintf(buf, "%u\n", ts->disabled);
348 }
349 
350 static ssize_t ad7879_disable_store(struct device *dev,
351 				     struct device_attribute *attr,
352 				     const char *buf, size_t count)
353 {
354 	struct ad7879 *ts = dev_get_drvdata(dev);
355 	unsigned int val;
356 	int error;
357 
358 	error = kstrtouint(buf, 10, &val);
359 	if (error)
360 		return error;
361 
362 	ad7879_toggle(ts, val);
363 
364 	return count;
365 }
366 
367 static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
368 
369 static struct attribute *ad7879_attributes[] = {
370 	&dev_attr_disable.attr,
371 	NULL
372 };
373 
374 static const struct attribute_group ad7879_attr_group = {
375 	.attrs = ad7879_attributes,
376 };
377 
378 #ifdef CONFIG_GPIOLIB
379 static int ad7879_gpio_direction_input(struct gpio_chip *chip,
380 					unsigned gpio)
381 {
382 	struct ad7879 *ts = gpiochip_get_data(chip);
383 	int err;
384 
385 	mutex_lock(&ts->mutex);
386 	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
387 	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
388 	mutex_unlock(&ts->mutex);
389 
390 	return err;
391 }
392 
393 static int ad7879_gpio_direction_output(struct gpio_chip *chip,
394 					unsigned gpio, int level)
395 {
396 	struct ad7879 *ts = gpiochip_get_data(chip);
397 	int err;
398 
399 	mutex_lock(&ts->mutex);
400 	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
401 	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
402 	if (level)
403 		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
404 	else
405 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
406 
407 	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
408 	mutex_unlock(&ts->mutex);
409 
410 	return err;
411 }
412 
413 static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
414 {
415 	struct ad7879 *ts = gpiochip_get_data(chip);
416 	u16 val;
417 
418 	mutex_lock(&ts->mutex);
419 	val = ad7879_read(ts, AD7879_REG_CTRL2);
420 	mutex_unlock(&ts->mutex);
421 
422 	return !!(val & AD7879_GPIO_DATA);
423 }
424 
425 static void ad7879_gpio_set_value(struct gpio_chip *chip,
426 				  unsigned gpio, int value)
427 {
428 	struct ad7879 *ts = gpiochip_get_data(chip);
429 
430 	mutex_lock(&ts->mutex);
431 	if (value)
432 		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
433 	else
434 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
435 
436 	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
437 	mutex_unlock(&ts->mutex);
438 }
439 
440 static int ad7879_gpio_add(struct ad7879 *ts,
441 			   const struct ad7879_platform_data *pdata)
442 {
443 	int ret = 0;
444 
445 	mutex_init(&ts->mutex);
446 
447 	if (pdata->gpio_export) {
448 		ts->gc.direction_input = ad7879_gpio_direction_input;
449 		ts->gc.direction_output = ad7879_gpio_direction_output;
450 		ts->gc.get = ad7879_gpio_get_value;
451 		ts->gc.set = ad7879_gpio_set_value;
452 		ts->gc.can_sleep = 1;
453 		ts->gc.base = pdata->gpio_base;
454 		ts->gc.ngpio = 1;
455 		ts->gc.label = "AD7879-GPIO";
456 		ts->gc.owner = THIS_MODULE;
457 		ts->gc.parent = ts->dev;
458 
459 		ret = gpiochip_add_data(&ts->gc, ts);
460 		if (ret)
461 			dev_err(ts->dev, "failed to register gpio %d\n",
462 				ts->gc.base);
463 	}
464 
465 	return ret;
466 }
467 
468 static void ad7879_gpio_remove(struct ad7879 *ts)
469 {
470 	const struct ad7879_platform_data *pdata = dev_get_platdata(ts->dev);
471 
472 	if (pdata && pdata->gpio_export)
473 		gpiochip_remove(&ts->gc);
474 
475 }
476 #else
477 static inline int ad7879_gpio_add(struct ad7879 *ts,
478 				  const struct ad7879_platform_data *pdata)
479 {
480 	return 0;
481 }
482 
483 static inline void ad7879_gpio_remove(struct ad7879 *ts)
484 {
485 }
486 #endif
487 
488 static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
489 {
490 	int err;
491 	u32 tmp;
492 
493 	err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
494 	if (err) {
495 		dev_err(dev, "failed to get resistance-plate-x property\n");
496 		return err;
497 	}
498 	ts->x_plate_ohms = (u16)tmp;
499 
500 	device_property_read_u8(dev, "adi,first-conversion-delay",
501 				&ts->first_conversion_delay);
502 	device_property_read_u8(dev, "adi,acquisition-time",
503 				&ts->acquisition_time);
504 	device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
505 	device_property_read_u8(dev, "adi,averaging", &ts->averaging);
506 	device_property_read_u8(dev, "adi,conversion-interval",
507 				&ts->pen_down_acc_interval);
508 
509 	ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
510 
511 	return 0;
512 }
513 
514 struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
515 			    const struct ad7879_bus_ops *bops)
516 {
517 	struct ad7879_platform_data *pdata = dev_get_platdata(dev);
518 	struct ad7879 *ts;
519 	struct input_dev *input_dev;
520 	int err;
521 	u16 revid;
522 
523 	if (!irq) {
524 		dev_err(dev, "No IRQ specified\n");
525 		return ERR_PTR(-EINVAL);
526 	}
527 
528 	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
529 	if (!ts)
530 		return ERR_PTR(-ENOMEM);
531 
532 	if (pdata) {
533 		/* Platform data use swapped axis (backward compatibility) */
534 		ts->swap_xy = !pdata->swap_xy;
535 
536 		ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
537 
538 		ts->first_conversion_delay = pdata->first_conversion_delay;
539 		ts->acquisition_time = pdata->acquisition_time;
540 		ts->averaging = pdata->averaging;
541 		ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
542 		ts->median = pdata->median;
543 	} else if (dev->of_node) {
544 		ad7879_parse_dt(dev, ts);
545 	} else {
546 		dev_err(dev, "No platform data\n");
547 		return ERR_PTR(-EINVAL);
548 	}
549 
550 	input_dev = devm_input_allocate_device(dev);
551 	if (!input_dev) {
552 		dev_err(dev, "Failed to allocate input device\n");
553 		return ERR_PTR(-ENOMEM);
554 	}
555 
556 	ts->bops = bops;
557 	ts->dev = dev;
558 	ts->input = input_dev;
559 	ts->irq = irq;
560 
561 	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
562 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
563 
564 	input_dev->name = "AD7879 Touchscreen";
565 	input_dev->phys = ts->phys;
566 	input_dev->dev.parent = dev;
567 	input_dev->id.bustype = bops->bustype;
568 
569 	input_dev->open = ad7879_open;
570 	input_dev->close = ad7879_close;
571 
572 	input_set_drvdata(input_dev, ts);
573 
574 	__set_bit(EV_ABS, input_dev->evbit);
575 	__set_bit(ABS_X, input_dev->absbit);
576 	__set_bit(ABS_Y, input_dev->absbit);
577 	__set_bit(ABS_PRESSURE, input_dev->absbit);
578 
579 	__set_bit(EV_KEY, input_dev->evbit);
580 	__set_bit(BTN_TOUCH, input_dev->keybit);
581 
582 	if (pdata) {
583 		input_set_abs_params(input_dev, ABS_X,
584 				pdata->x_min ? : 0,
585 				pdata->x_max ? : MAX_12BIT,
586 				0, 0);
587 		input_set_abs_params(input_dev, ABS_Y,
588 				pdata->y_min ? : 0,
589 				pdata->y_max ? : MAX_12BIT,
590 				0, 0);
591 		input_set_abs_params(input_dev, ABS_PRESSURE,
592 				pdata->pressure_min,
593 				pdata->pressure_max ? : ~0,
594 				0, 0);
595 	} else {
596 		input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
597 		input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
598 		touchscreen_parse_properties(input_dev, false, NULL);
599 		if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
600 			dev_err(dev, "Touchscreen pressure is not specified\n");
601 			return ERR_PTR(-EINVAL);
602 		}
603 	}
604 
605 	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
606 	if (err < 0) {
607 		dev_err(dev, "Failed to write %s\n", input_dev->name);
608 		return ERR_PTR(err);
609 	}
610 
611 	revid = ad7879_read(ts, AD7879_REG_REVID);
612 	input_dev->id.product = (revid & 0xff);
613 	input_dev->id.version = revid >> 8;
614 	if (input_dev->id.product != devid) {
615 		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
616 			input_dev->name, devid, revid);
617 		return ERR_PTR(-ENODEV);
618 	}
619 
620 	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
621 			AD7879_XPLUS_BIT |
622 			AD7879_Z2_BIT |
623 			AD7879_Z1_BIT |
624 			AD7879_TEMPMASK_BIT |
625 			AD7879_AUXVBATMASK_BIT |
626 			AD7879_GPIOALERTMASK_BIT;
627 
628 	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
629 			AD7879_AVG(ts->averaging) |
630 			AD7879_MFS(ts->median) |
631 			AD7879_FCD(ts->first_conversion_delay);
632 
633 	ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
634 			AD7879_ACQ(ts->acquisition_time) |
635 			AD7879_TMR(ts->pen_down_acc_interval);
636 
637 	err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
638 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
639 					dev_name(dev), ts);
640 	if (err) {
641 		dev_err(dev, "Failed to request IRQ: %d\n", err);
642 		return ERR_PTR(err);
643 	}
644 
645 	__ad7879_disable(ts);
646 
647 	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
648 	if (err)
649 		goto err_out;
650 
651 	if (pdata) {
652 		err = ad7879_gpio_add(ts, pdata);
653 		if (err)
654 			goto err_remove_attr;
655 	}
656 
657 	err = input_register_device(input_dev);
658 	if (err)
659 		goto err_remove_gpio;
660 
661 	return ts;
662 
663 err_remove_gpio:
664 	ad7879_gpio_remove(ts);
665 err_remove_attr:
666 	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
667 err_out:
668 	return ERR_PTR(err);
669 }
670 EXPORT_SYMBOL(ad7879_probe);
671 
672 void ad7879_remove(struct ad7879 *ts)
673 {
674 	ad7879_gpio_remove(ts);
675 	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
676 }
677 EXPORT_SYMBOL(ad7879_remove);
678 
679 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
680 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
681 MODULE_LICENSE("GPL");
682