xref: /linux/drivers/input/touchscreen/cyttsp_core.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9) 
1 /*
2  * Core Source for:
3  * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
4  * For use with Cypress Txx3xx parts.
5  * Supported parts include:
6  * CY8CTST341
7  * CY8CTMA340
8  *
9  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
10  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * version 2, and only version 2, as published by the
15  * Free Software Foundation.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along
23  * with this program; if not, write to the Free Software Foundation, Inc.,
24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25  *
26  * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
27  *
28  */
29 
30 #include <linux/delay.h>
31 #include <linux/input.h>
32 #include <linux/input/mt.h>
33 #include <linux/input/touchscreen.h>
34 #include <linux/gpio.h>
35 #include <linux/interrupt.h>
36 #include <linux/slab.h>
37 #include <linux/property.h>
38 #include <linux/gpio/consumer.h>
39 
40 #include "cyttsp_core.h"
41 
42 /* Bootloader number of command keys */
43 #define CY_NUM_BL_KEYS		8
44 
45 /* helpers */
46 #define GET_NUM_TOUCHES(x)		((x) & 0x0F)
47 #define IS_LARGE_AREA(x)		(((x) & 0x10) >> 4)
48 #define IS_BAD_PKT(x)			((x) & 0x20)
49 #define IS_VALID_APP(x)			((x) & 0x01)
50 #define IS_OPERATIONAL_ERR(x)		((x) & 0x3F)
51 #define GET_HSTMODE(reg)		(((reg) & 0x70) >> 4)
52 #define GET_BOOTLOADERMODE(reg)		(((reg) & 0x10) >> 4)
53 
54 #define CY_REG_BASE			0x00
55 #define CY_REG_ACT_DIST			0x1E
56 #define CY_REG_ACT_INTRVL		0x1D
57 #define CY_REG_TCH_TMOUT		(CY_REG_ACT_INTRVL + 1)
58 #define CY_REG_LP_INTRVL		(CY_REG_TCH_TMOUT + 1)
59 #define CY_MAXZ				255
60 #define CY_DELAY_DFLT			20 /* ms */
61 #define CY_DELAY_MAX			500
62 #define CY_ACT_DIST_DFLT		0xF8
63 #define CY_ACT_DIST_MASK		0x0F
64 #define CY_HNDSHK_BIT			0x80
65 /* device mode bits */
66 #define CY_OPERATE_MODE			0x00
67 #define CY_SYSINFO_MODE			0x10
68 /* power mode select bits */
69 #define CY_SOFT_RESET_MODE		0x01 /* return to Bootloader mode */
70 #define CY_DEEP_SLEEP_MODE		0x02
71 #define CY_LOW_POWER_MODE		0x04
72 
73 /* Slots management */
74 #define CY_MAX_FINGER			4
75 #define CY_MAX_ID			16
76 
77 static const u8 bl_command[] = {
78 	0x00,			/* file offset */
79 	0xFF,			/* command */
80 	0xA5,			/* exit bootloader command */
81 	0, 1, 2, 3, 4, 5, 6, 7	/* default keys */
82 };
83 
84 static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
85 				u8 length, void *buf)
86 {
87 	int error;
88 	int tries;
89 
90 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
91 		error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
92 				length, buf);
93 		if (!error)
94 			return 0;
95 
96 		msleep(CY_DELAY_DFLT);
97 	}
98 
99 	return -EIO;
100 }
101 
102 static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
103 				 u8 length, void *buf)
104 {
105 	int error;
106 	int tries;
107 
108 	for (tries = 0; tries < CY_NUM_RETRY; tries++) {
109 		error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
110 				length, buf);
111 		if (!error)
112 			return 0;
113 
114 		msleep(CY_DELAY_DFLT);
115 	}
116 
117 	return -EIO;
118 }
119 
120 static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
121 {
122 	return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
123 }
124 
125 static int cyttsp_handshake(struct cyttsp *ts)
126 {
127 	if (ts->use_hndshk)
128 		return ttsp_send_command(ts,
129 				ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
130 
131 	return 0;
132 }
133 
134 static int cyttsp_load_bl_regs(struct cyttsp *ts)
135 {
136 	memset(&ts->bl_data, 0, sizeof(ts->bl_data));
137 	ts->bl_data.bl_status = 0x10;
138 
139 	return ttsp_read_block_data(ts, CY_REG_BASE,
140 				    sizeof(ts->bl_data), &ts->bl_data);
141 }
142 
143 static int cyttsp_exit_bl_mode(struct cyttsp *ts)
144 {
145 	int error;
146 	u8 bl_cmd[sizeof(bl_command)];
147 
148 	memcpy(bl_cmd, bl_command, sizeof(bl_command));
149 	if (ts->bl_keys)
150 		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
151 			ts->bl_keys, CY_NUM_BL_KEYS);
152 
153 	error = ttsp_write_block_data(ts, CY_REG_BASE,
154 				      sizeof(bl_cmd), bl_cmd);
155 	if (error)
156 		return error;
157 
158 	/* wait for TTSP Device to complete the operation */
159 	msleep(CY_DELAY_DFLT);
160 
161 	error = cyttsp_load_bl_regs(ts);
162 	if (error)
163 		return error;
164 
165 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
166 		return -EIO;
167 
168 	return 0;
169 }
170 
171 static int cyttsp_set_operational_mode(struct cyttsp *ts)
172 {
173 	int error;
174 
175 	error = ttsp_send_command(ts, CY_OPERATE_MODE);
176 	if (error)
177 		return error;
178 
179 	/* wait for TTSP Device to complete switch to Operational mode */
180 	error = ttsp_read_block_data(ts, CY_REG_BASE,
181 				     sizeof(ts->xy_data), &ts->xy_data);
182 	if (error)
183 		return error;
184 
185 	error = cyttsp_handshake(ts);
186 	if (error)
187 		return error;
188 
189 	return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
190 }
191 
192 static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
193 {
194 	int error;
195 
196 	memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));
197 
198 	/* switch to sysinfo mode */
199 	error = ttsp_send_command(ts, CY_SYSINFO_MODE);
200 	if (error)
201 		return error;
202 
203 	/* read sysinfo registers */
204 	msleep(CY_DELAY_DFLT);
205 	error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
206 				      &ts->sysinfo_data);
207 	if (error)
208 		return error;
209 
210 	error = cyttsp_handshake(ts);
211 	if (error)
212 		return error;
213 
214 	if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
215 		return -EIO;
216 
217 	return 0;
218 }
219 
220 static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
221 {
222 	int retval = 0;
223 
224 	if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
225 	    ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
226 	    ts->lp_intrvl != CY_LP_INTRVL_DFLT) {
227 
228 		u8 intrvl_ray[] = {
229 			ts->act_intrvl,
230 			ts->tch_tmout,
231 			ts->lp_intrvl
232 		};
233 
234 		/* set intrvl registers */
235 		retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
236 					sizeof(intrvl_ray), intrvl_ray);
237 		msleep(CY_DELAY_DFLT);
238 	}
239 
240 	return retval;
241 }
242 
243 static void cyttsp_hard_reset(struct cyttsp *ts)
244 {
245 	if (ts->reset_gpio) {
246 		gpiod_set_value_cansleep(ts->reset_gpio, 1);
247 		msleep(CY_DELAY_DFLT);
248 		gpiod_set_value_cansleep(ts->reset_gpio, 0);
249 		msleep(CY_DELAY_DFLT);
250 	}
251 }
252 
253 static int cyttsp_soft_reset(struct cyttsp *ts)
254 {
255 	unsigned long timeout;
256 	int retval;
257 
258 	/* wait for interrupt to set ready completion */
259 	reinit_completion(&ts->bl_ready);
260 	ts->state = CY_BL_STATE;
261 
262 	enable_irq(ts->irq);
263 
264 	retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
265 	if (retval)
266 		goto out;
267 
268 	timeout = wait_for_completion_timeout(&ts->bl_ready,
269 			msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
270 	retval = timeout ? 0 : -EIO;
271 
272 out:
273 	ts->state = CY_IDLE_STATE;
274 	disable_irq(ts->irq);
275 	return retval;
276 }
277 
278 static int cyttsp_act_dist_setup(struct cyttsp *ts)
279 {
280 	u8 act_dist_setup = ts->act_dist;
281 
282 	/* Init gesture; active distance setup */
283 	return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
284 				sizeof(act_dist_setup), &act_dist_setup);
285 }
286 
287 static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
288 {
289 	ids[0] = xy_data->touch12_id >> 4;
290 	ids[1] = xy_data->touch12_id & 0xF;
291 	ids[2] = xy_data->touch34_id >> 4;
292 	ids[3] = xy_data->touch34_id & 0xF;
293 }
294 
295 static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
296 					       int idx)
297 {
298 	switch (idx) {
299 	case 0:
300 		return &xy_data->tch1;
301 	case 1:
302 		return &xy_data->tch2;
303 	case 2:
304 		return &xy_data->tch3;
305 	case 3:
306 		return &xy_data->tch4;
307 	default:
308 		return NULL;
309 	}
310 }
311 
312 static void cyttsp_report_tchdata(struct cyttsp *ts)
313 {
314 	struct cyttsp_xydata *xy_data = &ts->xy_data;
315 	struct input_dev *input = ts->input;
316 	int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
317 	const struct cyttsp_tch *tch;
318 	int ids[CY_MAX_ID];
319 	int i;
320 	DECLARE_BITMAP(used, CY_MAX_ID);
321 
322 	if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
323 		/* terminate all active tracks */
324 		num_tch = 0;
325 		dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
326 	} else if (num_tch > CY_MAX_FINGER) {
327 		/* terminate all active tracks */
328 		num_tch = 0;
329 		dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
330 	} else if (IS_BAD_PKT(xy_data->tt_mode)) {
331 		/* terminate all active tracks */
332 		num_tch = 0;
333 		dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
334 	}
335 
336 	cyttsp_extract_track_ids(xy_data, ids);
337 
338 	bitmap_zero(used, CY_MAX_ID);
339 
340 	for (i = 0; i < num_tch; i++) {
341 		tch = cyttsp_get_tch(xy_data, i);
342 
343 		input_mt_slot(input, ids[i]);
344 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
345 		input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
346 		input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
347 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);
348 
349 		__set_bit(ids[i], used);
350 	}
351 
352 	for (i = 0; i < CY_MAX_ID; i++) {
353 		if (test_bit(i, used))
354 			continue;
355 
356 		input_mt_slot(input, i);
357 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
358 	}
359 
360 	input_sync(input);
361 }
362 
363 static irqreturn_t cyttsp_irq(int irq, void *handle)
364 {
365 	struct cyttsp *ts = handle;
366 	int error;
367 
368 	if (unlikely(ts->state == CY_BL_STATE)) {
369 		complete(&ts->bl_ready);
370 		goto out;
371 	}
372 
373 	/* Get touch data from CYTTSP device */
374 	error = ttsp_read_block_data(ts, CY_REG_BASE,
375 				 sizeof(struct cyttsp_xydata), &ts->xy_data);
376 	if (error)
377 		goto out;
378 
379 	/* provide flow control handshake */
380 	error = cyttsp_handshake(ts);
381 	if (error)
382 		goto out;
383 
384 	if (unlikely(ts->state == CY_IDLE_STATE))
385 		goto out;
386 
387 	if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
388 		/*
389 		 * TTSP device has reset back to bootloader mode.
390 		 * Restore to operational mode.
391 		 */
392 		error = cyttsp_exit_bl_mode(ts);
393 		if (error) {
394 			dev_err(ts->dev,
395 				"Could not return to operational mode, err: %d\n",
396 				error);
397 			ts->state = CY_IDLE_STATE;
398 		}
399 	} else {
400 		cyttsp_report_tchdata(ts);
401 	}
402 
403 out:
404 	return IRQ_HANDLED;
405 }
406 
407 static int cyttsp_power_on(struct cyttsp *ts)
408 {
409 	int error;
410 
411 	error = cyttsp_soft_reset(ts);
412 	if (error)
413 		return error;
414 
415 	error = cyttsp_load_bl_regs(ts);
416 	if (error)
417 		return error;
418 
419 	if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
420 	    IS_VALID_APP(ts->bl_data.bl_status)) {
421 		error = cyttsp_exit_bl_mode(ts);
422 		if (error)
423 			return error;
424 	}
425 
426 	if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
427 	    IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
428 		return -ENODEV;
429 	}
430 
431 	error = cyttsp_set_sysinfo_mode(ts);
432 	if (error)
433 		return error;
434 
435 	error = cyttsp_set_sysinfo_regs(ts);
436 	if (error)
437 		return error;
438 
439 	error = cyttsp_set_operational_mode(ts);
440 	if (error)
441 		return error;
442 
443 	/* init active distance */
444 	error = cyttsp_act_dist_setup(ts);
445 	if (error)
446 		return error;
447 
448 	ts->state = CY_ACTIVE_STATE;
449 
450 	return 0;
451 }
452 
453 static int cyttsp_enable(struct cyttsp *ts)
454 {
455 	int error;
456 
457 	/*
458 	 * The device firmware can wake on an I2C or SPI memory slave
459 	 * address match. So just reading a register is sufficient to
460 	 * wake up the device. The first read attempt will fail but it
461 	 * will wake it up making the second read attempt successful.
462 	 */
463 	error = ttsp_read_block_data(ts, CY_REG_BASE,
464 				     sizeof(ts->xy_data), &ts->xy_data);
465 	if (error)
466 		return error;
467 
468 	if (GET_HSTMODE(ts->xy_data.hst_mode))
469 		return -EIO;
470 
471 	enable_irq(ts->irq);
472 
473 	return 0;
474 }
475 
476 static int cyttsp_disable(struct cyttsp *ts)
477 {
478 	int error;
479 
480 	error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
481 	if (error)
482 		return error;
483 
484 	disable_irq(ts->irq);
485 
486 	return 0;
487 }
488 
489 static int __maybe_unused cyttsp_suspend(struct device *dev)
490 {
491 	struct cyttsp *ts = dev_get_drvdata(dev);
492 	int retval = 0;
493 
494 	mutex_lock(&ts->input->mutex);
495 
496 	if (ts->input->users) {
497 		retval = cyttsp_disable(ts);
498 		if (retval == 0)
499 			ts->suspended = true;
500 	}
501 
502 	mutex_unlock(&ts->input->mutex);
503 
504 	return retval;
505 }
506 
507 static int __maybe_unused cyttsp_resume(struct device *dev)
508 {
509 	struct cyttsp *ts = dev_get_drvdata(dev);
510 
511 	mutex_lock(&ts->input->mutex);
512 
513 	if (ts->input->users)
514 		cyttsp_enable(ts);
515 
516 	ts->suspended = false;
517 
518 	mutex_unlock(&ts->input->mutex);
519 
520 	return 0;
521 }
522 
523 SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
524 EXPORT_SYMBOL_GPL(cyttsp_pm_ops);
525 
526 static int cyttsp_open(struct input_dev *dev)
527 {
528 	struct cyttsp *ts = input_get_drvdata(dev);
529 	int retval = 0;
530 
531 	if (!ts->suspended)
532 		retval = cyttsp_enable(ts);
533 
534 	return retval;
535 }
536 
537 static void cyttsp_close(struct input_dev *dev)
538 {
539 	struct cyttsp *ts = input_get_drvdata(dev);
540 
541 	if (!ts->suspended)
542 		cyttsp_disable(ts);
543 }
544 
545 static int cyttsp_parse_properties(struct cyttsp *ts)
546 {
547 	struct device *dev = ts->dev;
548 	u32 dt_value;
549 	int ret;
550 
551 	ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
552 	if (!ts->bl_keys)
553 		return -ENOMEM;
554 
555 	/* Set some default values */
556 	ts->use_hndshk = false;
557 	ts->act_dist = CY_ACT_DIST_DFLT;
558 	ts->act_intrvl = CY_ACT_INTRVL_DFLT;
559 	ts->tch_tmout = CY_TCH_TMOUT_DFLT;
560 	ts->lp_intrvl = CY_LP_INTRVL_DFLT;
561 
562 	ret = device_property_read_u8_array(dev, "bootloader-key",
563 					    ts->bl_keys, CY_NUM_BL_KEYS);
564 	if (ret) {
565 		dev_err(dev,
566 			"bootloader-key property could not be retrieved\n");
567 		return ret;
568 	}
569 
570 	ts->use_hndshk = device_property_present(dev, "use-handshake");
571 
572 	if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
573 		if (dt_value > 15) {
574 			dev_err(dev, "active-distance (%u) must be [0-15]\n",
575 				dt_value);
576 			return -EINVAL;
577 		}
578 		ts->act_dist &= ~CY_ACT_DIST_MASK;
579 		ts->act_dist |= dt_value;
580 	}
581 
582 	if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
583 		if (dt_value > 255) {
584 			dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
585 				dt_value);
586 			return -EINVAL;
587 		}
588 		ts->act_intrvl = dt_value;
589 	}
590 
591 	if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
592 		if (dt_value > 2550) {
593 			dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
594 				dt_value);
595 			return -EINVAL;
596 		}
597 		/* Register value is expressed in 0.01s / bit */
598 		ts->lp_intrvl = dt_value / 10;
599 	}
600 
601 	if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
602 		if (dt_value > 2550) {
603 			dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
604 				dt_value);
605 			return -EINVAL;
606 		}
607 		/* Register value is expressed in 0.01s / bit */
608 		ts->tch_tmout = dt_value / 10;
609 	}
610 
611 	return 0;
612 }
613 
614 struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
615 			    struct device *dev, int irq, size_t xfer_buf_size)
616 {
617 	struct cyttsp *ts;
618 	struct input_dev *input_dev;
619 	int error;
620 
621 	ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
622 	if (!ts)
623 		return ERR_PTR(-ENOMEM);
624 
625 	input_dev = devm_input_allocate_device(dev);
626 	if (!input_dev)
627 		return ERR_PTR(-ENOMEM);
628 
629 	ts->dev = dev;
630 	ts->input = input_dev;
631 	ts->bus_ops = bus_ops;
632 	ts->irq = irq;
633 
634 	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
635 	if (IS_ERR(ts->reset_gpio)) {
636 		error = PTR_ERR(ts->reset_gpio);
637 		dev_err(dev, "Failed to request reset gpio, error %d\n", error);
638 		return ERR_PTR(error);
639 	}
640 
641 	error = cyttsp_parse_properties(ts);
642 	if (error)
643 		return ERR_PTR(error);
644 
645 	init_completion(&ts->bl_ready);
646 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
647 
648 	input_dev->name = "Cypress TTSP TouchScreen";
649 	input_dev->phys = ts->phys;
650 	input_dev->id.bustype = bus_ops->bustype;
651 	input_dev->dev.parent = ts->dev;
652 
653 	input_dev->open = cyttsp_open;
654 	input_dev->close = cyttsp_close;
655 
656 	input_set_drvdata(input_dev, ts);
657 
658 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
659 	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
660 	touchscreen_parse_properties(input_dev, true, NULL);
661 
662 	error = input_mt_init_slots(input_dev, CY_MAX_ID, 0);
663 	if (error) {
664 		dev_err(dev, "Unable to init MT slots.\n");
665 		return ERR_PTR(error);
666 	}
667 
668 	error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
669 					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
670 					  "cyttsp", ts);
671 	if (error) {
672 		dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
673 			ts->irq, error);
674 		return ERR_PTR(error);
675 	}
676 
677 	disable_irq(ts->irq);
678 
679 	cyttsp_hard_reset(ts);
680 
681 	error = cyttsp_power_on(ts);
682 	if (error)
683 		return ERR_PTR(error);
684 
685 	error = input_register_device(input_dev);
686 	if (error) {
687 		dev_err(ts->dev, "failed to register input device: %d\n",
688 			error);
689 		return ERR_PTR(error);
690 	}
691 
692 	return ts;
693 }
694 EXPORT_SYMBOL_GPL(cyttsp_probe);
695 
696 MODULE_LICENSE("GPL");
697 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
698 MODULE_AUTHOR("Cypress");
699