xref: /openbmc/linux/drivers/input/touchscreen/edt-ft5x06.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
1 /*
2  * Copyright (C) 2012 Simon Budig, <simon.budig@kernelconcepts.de>
3  * Daniel Wagener <daniel.wagener@kernelconcepts.de> (M09 firmware support)
4  * Lothar Waßmann <LW@KARO-electronics.de> (DT support)
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 
20 /*
21  * This is a driver for the EDT "Polytouch" family of touch controllers
22  * based on the FocalTech FT5x06 line of chips.
23  *
24  * Development of this driver has been sponsored by Glyn:
25  *    http://www.glyn.com/Products/Displays
26  */
27 
28 #include <linux/module.h>
29 #include <linux/ratelimit.h>
30 #include <linux/interrupt.h>
31 #include <linux/input.h>
32 #include <linux/i2c.h>
33 #include <linux/uaccess.h>
34 #include <linux/delay.h>
35 #include <linux/debugfs.h>
36 #include <linux/slab.h>
37 #include <linux/gpio.h>
38 #include <linux/of_gpio.h>
39 #include <linux/input/mt.h>
40 #include <linux/input/edt-ft5x06.h>
41 
42 #define MAX_SUPPORT_POINTS		5
43 
44 #define WORK_REGISTER_THRESHOLD		0x00
45 #define WORK_REGISTER_REPORT_RATE	0x08
46 #define WORK_REGISTER_GAIN		0x30
47 #define WORK_REGISTER_OFFSET		0x31
48 #define WORK_REGISTER_NUM_X		0x33
49 #define WORK_REGISTER_NUM_Y		0x34
50 
51 #define M09_REGISTER_THRESHOLD		0x80
52 #define M09_REGISTER_GAIN		0x92
53 #define M09_REGISTER_OFFSET		0x93
54 #define M09_REGISTER_NUM_X		0x94
55 #define M09_REGISTER_NUM_Y		0x95
56 
57 #define NO_REGISTER			0xff
58 
59 #define WORK_REGISTER_OPMODE		0x3c
60 #define FACTORY_REGISTER_OPMODE		0x01
61 
62 #define TOUCH_EVENT_DOWN		0x00
63 #define TOUCH_EVENT_UP			0x01
64 #define TOUCH_EVENT_ON			0x02
65 #define TOUCH_EVENT_RESERVED		0x03
66 
67 #define EDT_NAME_LEN			23
68 #define EDT_SWITCH_MODE_RETRIES		10
69 #define EDT_SWITCH_MODE_DELAY		5 /* msec */
70 #define EDT_RAW_DATA_RETRIES		100
71 #define EDT_RAW_DATA_DELAY		1 /* msec */
72 
73 enum edt_ver {
74 	M06,
75 	M09,
76 };
77 
78 struct edt_reg_addr {
79 	int reg_threshold;
80 	int reg_report_rate;
81 	int reg_gain;
82 	int reg_offset;
83 	int reg_num_x;
84 	int reg_num_y;
85 };
86 
87 struct edt_ft5x06_ts_data {
88 	struct i2c_client *client;
89 	struct input_dev *input;
90 	u16 num_x;
91 	u16 num_y;
92 
93 	int reset_pin;
94 	int irq_pin;
95 	int wake_pin;
96 
97 #if defined(CONFIG_DEBUG_FS)
98 	struct dentry *debug_dir;
99 	u8 *raw_buffer;
100 	size_t raw_bufsize;
101 #endif
102 
103 	struct mutex mutex;
104 	bool factory_mode;
105 	int threshold;
106 	int gain;
107 	int offset;
108 	int report_rate;
109 
110 	char name[EDT_NAME_LEN];
111 
112 	struct edt_reg_addr reg_addr;
113 	enum edt_ver version;
114 };
115 
116 static int edt_ft5x06_ts_readwrite(struct i2c_client *client,
117 				   u16 wr_len, u8 *wr_buf,
118 				   u16 rd_len, u8 *rd_buf)
119 {
120 	struct i2c_msg wrmsg[2];
121 	int i = 0;
122 	int ret;
123 
124 	if (wr_len) {
125 		wrmsg[i].addr  = client->addr;
126 		wrmsg[i].flags = 0;
127 		wrmsg[i].len = wr_len;
128 		wrmsg[i].buf = wr_buf;
129 		i++;
130 	}
131 	if (rd_len) {
132 		wrmsg[i].addr  = client->addr;
133 		wrmsg[i].flags = I2C_M_RD;
134 		wrmsg[i].len = rd_len;
135 		wrmsg[i].buf = rd_buf;
136 		i++;
137 	}
138 
139 	ret = i2c_transfer(client->adapter, wrmsg, i);
140 	if (ret < 0)
141 		return ret;
142 	if (ret != i)
143 		return -EIO;
144 
145 	return 0;
146 }
147 
148 static bool edt_ft5x06_ts_check_crc(struct edt_ft5x06_ts_data *tsdata,
149 				    u8 *buf, int buflen)
150 {
151 	int i;
152 	u8 crc = 0;
153 
154 	for (i = 0; i < buflen - 1; i++)
155 		crc ^= buf[i];
156 
157 	if (crc != buf[buflen-1]) {
158 		dev_err_ratelimited(&tsdata->client->dev,
159 				    "crc error: 0x%02x expected, got 0x%02x\n",
160 				    crc, buf[buflen-1]);
161 		return false;
162 	}
163 
164 	return true;
165 }
166 
167 static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
168 {
169 	struct edt_ft5x06_ts_data *tsdata = dev_id;
170 	struct device *dev = &tsdata->client->dev;
171 	u8 cmd;
172 	u8 rdbuf[29];
173 	int i, type, x, y, id;
174 	int offset, tplen, datalen;
175 	int error;
176 
177 	switch (tsdata->version) {
178 	case M06:
179 		cmd = 0xf9; /* tell the controller to send touch data */
180 		offset = 5; /* where the actual touch data starts */
181 		tplen = 4;  /* data comes in so called frames */
182 		datalen = 26; /* how much bytes to listen for */
183 		break;
184 
185 	case M09:
186 		cmd = 0x02;
187 		offset = 1;
188 		tplen = 6;
189 		datalen = 29;
190 		break;
191 
192 	default:
193 		goto out;
194 	}
195 
196 	memset(rdbuf, 0, sizeof(rdbuf));
197 
198 	error = edt_ft5x06_ts_readwrite(tsdata->client,
199 					sizeof(cmd), &cmd,
200 					datalen, rdbuf);
201 	if (error) {
202 		dev_err_ratelimited(dev, "Unable to fetch data, error: %d\n",
203 				    error);
204 		goto out;
205 	}
206 
207 	/* M09 does not send header or CRC */
208 	if (tsdata->version == M06) {
209 		if (rdbuf[0] != 0xaa || rdbuf[1] != 0xaa ||
210 			rdbuf[2] != datalen) {
211 			dev_err_ratelimited(dev,
212 					"Unexpected header: %02x%02x%02x!\n",
213 					rdbuf[0], rdbuf[1], rdbuf[2]);
214 			goto out;
215 		}
216 
217 		if (!edt_ft5x06_ts_check_crc(tsdata, rdbuf, datalen))
218 			goto out;
219 	}
220 
221 	for (i = 0; i < MAX_SUPPORT_POINTS; i++) {
222 		u8 *buf = &rdbuf[i * tplen + offset];
223 		bool down;
224 
225 		type = buf[0] >> 6;
226 		/* ignore Reserved events */
227 		if (type == TOUCH_EVENT_RESERVED)
228 			continue;
229 
230 		/* M06 sometimes sends bogus coordinates in TOUCH_DOWN */
231 		if (tsdata->version == M06 && type == TOUCH_EVENT_DOWN)
232 			continue;
233 
234 		x = ((buf[0] << 8) | buf[1]) & 0x0fff;
235 		y = ((buf[2] << 8) | buf[3]) & 0x0fff;
236 		id = (buf[2] >> 4) & 0x0f;
237 		down = type != TOUCH_EVENT_UP;
238 
239 		input_mt_slot(tsdata->input, id);
240 		input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER, down);
241 
242 		if (!down)
243 			continue;
244 
245 		input_report_abs(tsdata->input, ABS_MT_POSITION_X, x);
246 		input_report_abs(tsdata->input, ABS_MT_POSITION_Y, y);
247 	}
248 
249 	input_mt_report_pointer_emulation(tsdata->input, true);
250 	input_sync(tsdata->input);
251 
252 out:
253 	return IRQ_HANDLED;
254 }
255 
256 static int edt_ft5x06_register_write(struct edt_ft5x06_ts_data *tsdata,
257 				     u8 addr, u8 value)
258 {
259 	u8 wrbuf[4];
260 
261 	switch (tsdata->version) {
262 	case M06:
263 		wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
264 		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
265 		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
266 		wrbuf[2] = value;
267 		wrbuf[3] = wrbuf[0] ^ wrbuf[1] ^ wrbuf[2];
268 		return edt_ft5x06_ts_readwrite(tsdata->client, 4,
269 					wrbuf, 0, NULL);
270 	case M09:
271 		wrbuf[0] = addr;
272 		wrbuf[1] = value;
273 
274 		return edt_ft5x06_ts_readwrite(tsdata->client, 3,
275 					wrbuf, 0, NULL);
276 
277 	default:
278 		return -EINVAL;
279 	}
280 }
281 
282 static int edt_ft5x06_register_read(struct edt_ft5x06_ts_data *tsdata,
283 				    u8 addr)
284 {
285 	u8 wrbuf[2], rdbuf[2];
286 	int error;
287 
288 	switch (tsdata->version) {
289 	case M06:
290 		wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
291 		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
292 		wrbuf[1] |= tsdata->factory_mode ? 0x80 : 0x40;
293 
294 		error = edt_ft5x06_ts_readwrite(tsdata->client, 2, wrbuf, 2,
295 						rdbuf);
296 		if (error)
297 			return error;
298 
299 		if ((wrbuf[0] ^ wrbuf[1] ^ rdbuf[0]) != rdbuf[1]) {
300 			dev_err(&tsdata->client->dev,
301 				"crc error: 0x%02x expected, got 0x%02x\n",
302 				wrbuf[0] ^ wrbuf[1] ^ rdbuf[0],
303 				rdbuf[1]);
304 			return -EIO;
305 		}
306 		break;
307 
308 	case M09:
309 		wrbuf[0] = addr;
310 		error = edt_ft5x06_ts_readwrite(tsdata->client, 1,
311 						wrbuf, 1, rdbuf);
312 		if (error)
313 			return error;
314 		break;
315 
316 	default:
317 		return -EINVAL;
318 	}
319 
320 	return rdbuf[0];
321 }
322 
323 struct edt_ft5x06_attribute {
324 	struct device_attribute dattr;
325 	size_t field_offset;
326 	u8 limit_low;
327 	u8 limit_high;
328 	u8 addr_m06;
329 	u8 addr_m09;
330 };
331 
332 #define EDT_ATTR(_field, _mode, _addr_m06, _addr_m09,			\
333 		_limit_low, _limit_high)				\
334 	struct edt_ft5x06_attribute edt_ft5x06_attr_##_field = {	\
335 		.dattr = __ATTR(_field, _mode,				\
336 				edt_ft5x06_setting_show,		\
337 				edt_ft5x06_setting_store),		\
338 		.field_offset = offsetof(struct edt_ft5x06_ts_data, _field), \
339 		.addr_m06 = _addr_m06,					\
340 		.addr_m09 = _addr_m09,					\
341 		.limit_low = _limit_low,				\
342 		.limit_high = _limit_high,				\
343 	}
344 
345 static ssize_t edt_ft5x06_setting_show(struct device *dev,
346 				       struct device_attribute *dattr,
347 				       char *buf)
348 {
349 	struct i2c_client *client = to_i2c_client(dev);
350 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
351 	struct edt_ft5x06_attribute *attr =
352 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
353 	u8 *field = (u8 *)tsdata + attr->field_offset;
354 	int val;
355 	size_t count = 0;
356 	int error = 0;
357 	u8 addr;
358 
359 	mutex_lock(&tsdata->mutex);
360 
361 	if (tsdata->factory_mode) {
362 		error = -EIO;
363 		goto out;
364 	}
365 
366 	switch (tsdata->version) {
367 	case M06:
368 		addr = attr->addr_m06;
369 		break;
370 
371 	case M09:
372 		addr = attr->addr_m09;
373 		break;
374 
375 	default:
376 		error = -ENODEV;
377 		goto out;
378 	}
379 
380 	if (addr != NO_REGISTER) {
381 		val = edt_ft5x06_register_read(tsdata, addr);
382 		if (val < 0) {
383 			error = val;
384 			dev_err(&tsdata->client->dev,
385 				"Failed to fetch attribute %s, error %d\n",
386 				dattr->attr.name, error);
387 			goto out;
388 		}
389 	} else {
390 		val = *field;
391 	}
392 
393 	if (val != *field) {
394 		dev_warn(&tsdata->client->dev,
395 			 "%s: read (%d) and stored value (%d) differ\n",
396 			 dattr->attr.name, val, *field);
397 		*field = val;
398 	}
399 
400 	count = scnprintf(buf, PAGE_SIZE, "%d\n", val);
401 out:
402 	mutex_unlock(&tsdata->mutex);
403 	return error ?: count;
404 }
405 
406 static ssize_t edt_ft5x06_setting_store(struct device *dev,
407 					struct device_attribute *dattr,
408 					const char *buf, size_t count)
409 {
410 	struct i2c_client *client = to_i2c_client(dev);
411 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
412 	struct edt_ft5x06_attribute *attr =
413 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
414 	u8 *field = (u8 *)tsdata + attr->field_offset;
415 	unsigned int val;
416 	int error;
417 	u8 addr;
418 
419 	mutex_lock(&tsdata->mutex);
420 
421 	if (tsdata->factory_mode) {
422 		error = -EIO;
423 		goto out;
424 	}
425 
426 	error = kstrtouint(buf, 0, &val);
427 	if (error)
428 		goto out;
429 
430 	if (val < attr->limit_low || val > attr->limit_high) {
431 		error = -ERANGE;
432 		goto out;
433 	}
434 
435 	switch (tsdata->version) {
436 	case M06:
437 		addr = attr->addr_m06;
438 		break;
439 
440 	case M09:
441 		addr = attr->addr_m09;
442 		break;
443 
444 	default:
445 		error = -ENODEV;
446 		goto out;
447 	}
448 
449 	if (addr != NO_REGISTER) {
450 		error = edt_ft5x06_register_write(tsdata, addr, val);
451 		if (error) {
452 			dev_err(&tsdata->client->dev,
453 				"Failed to update attribute %s, error: %d\n",
454 				dattr->attr.name, error);
455 			goto out;
456 		}
457 	}
458 	*field = val;
459 
460 out:
461 	mutex_unlock(&tsdata->mutex);
462 	return error ?: count;
463 }
464 
465 static EDT_ATTR(gain, S_IWUSR | S_IRUGO, WORK_REGISTER_GAIN,
466 		M09_REGISTER_GAIN, 0, 31);
467 static EDT_ATTR(offset, S_IWUSR | S_IRUGO, WORK_REGISTER_OFFSET,
468 		M09_REGISTER_OFFSET, 0, 31);
469 static EDT_ATTR(threshold, S_IWUSR | S_IRUGO, WORK_REGISTER_THRESHOLD,
470 		M09_REGISTER_THRESHOLD, 20, 80);
471 static EDT_ATTR(report_rate, S_IWUSR | S_IRUGO, WORK_REGISTER_REPORT_RATE,
472 		NO_REGISTER, 3, 14);
473 
474 static struct attribute *edt_ft5x06_attrs[] = {
475 	&edt_ft5x06_attr_gain.dattr.attr,
476 	&edt_ft5x06_attr_offset.dattr.attr,
477 	&edt_ft5x06_attr_threshold.dattr.attr,
478 	&edt_ft5x06_attr_report_rate.dattr.attr,
479 	NULL
480 };
481 
482 static const struct attribute_group edt_ft5x06_attr_group = {
483 	.attrs = edt_ft5x06_attrs,
484 };
485 
486 #ifdef CONFIG_DEBUG_FS
487 static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
488 {
489 	struct i2c_client *client = tsdata->client;
490 	int retries = EDT_SWITCH_MODE_RETRIES;
491 	int ret;
492 	int error;
493 
494 	disable_irq(client->irq);
495 
496 	if (!tsdata->raw_buffer) {
497 		tsdata->raw_bufsize = tsdata->num_x * tsdata->num_y *
498 				      sizeof(u16);
499 		tsdata->raw_buffer = kzalloc(tsdata->raw_bufsize, GFP_KERNEL);
500 		if (!tsdata->raw_buffer) {
501 			error = -ENOMEM;
502 			goto err_out;
503 		}
504 	}
505 
506 	/* mode register is 0x3c when in the work mode */
507 	if (tsdata->version == M09)
508 		goto m09_out;
509 
510 	error = edt_ft5x06_register_write(tsdata, WORK_REGISTER_OPMODE, 0x03);
511 	if (error) {
512 		dev_err(&client->dev,
513 			"failed to switch to factory mode, error %d\n", error);
514 		goto err_out;
515 	}
516 
517 	tsdata->factory_mode = true;
518 	do {
519 		mdelay(EDT_SWITCH_MODE_DELAY);
520 		/* mode register is 0x01 when in factory mode */
521 		ret = edt_ft5x06_register_read(tsdata, FACTORY_REGISTER_OPMODE);
522 		if (ret == 0x03)
523 			break;
524 	} while (--retries > 0);
525 
526 	if (retries == 0) {
527 		dev_err(&client->dev, "not in factory mode after %dms.\n",
528 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
529 		error = -EIO;
530 		goto err_out;
531 	}
532 
533 	return 0;
534 
535 err_out:
536 	kfree(tsdata->raw_buffer);
537 	tsdata->raw_buffer = NULL;
538 	tsdata->factory_mode = false;
539 	enable_irq(client->irq);
540 
541 	return error;
542 
543 m09_out:
544 	dev_err(&client->dev, "No factory mode support for M09\n");
545 	return -EINVAL;
546 
547 }
548 
549 static int edt_ft5x06_work_mode(struct edt_ft5x06_ts_data *tsdata)
550 {
551 	struct i2c_client *client = tsdata->client;
552 	int retries = EDT_SWITCH_MODE_RETRIES;
553 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
554 	int ret;
555 	int error;
556 
557 	/* mode register is 0x01 when in the factory mode */
558 	error = edt_ft5x06_register_write(tsdata, FACTORY_REGISTER_OPMODE, 0x1);
559 	if (error) {
560 		dev_err(&client->dev,
561 			"failed to switch to work mode, error: %d\n", error);
562 		return error;
563 	}
564 
565 	tsdata->factory_mode = false;
566 
567 	do {
568 		mdelay(EDT_SWITCH_MODE_DELAY);
569 		/* mode register is 0x01 when in factory mode */
570 		ret = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OPMODE);
571 		if (ret == 0x01)
572 			break;
573 	} while (--retries > 0);
574 
575 	if (retries == 0) {
576 		dev_err(&client->dev, "not in work mode after %dms.\n",
577 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
578 		tsdata->factory_mode = true;
579 		return -EIO;
580 	}
581 
582 	kfree(tsdata->raw_buffer);
583 	tsdata->raw_buffer = NULL;
584 
585 	/* restore parameters */
586 	edt_ft5x06_register_write(tsdata, reg_addr->reg_threshold,
587 				  tsdata->threshold);
588 	edt_ft5x06_register_write(tsdata, reg_addr->reg_gain,
589 				  tsdata->gain);
590 	edt_ft5x06_register_write(tsdata, reg_addr->reg_offset,
591 				  tsdata->offset);
592 	if (reg_addr->reg_report_rate)
593 		edt_ft5x06_register_write(tsdata, reg_addr->reg_report_rate,
594 				  tsdata->report_rate);
595 
596 	enable_irq(client->irq);
597 
598 	return 0;
599 }
600 
601 static int edt_ft5x06_debugfs_mode_get(void *data, u64 *mode)
602 {
603 	struct edt_ft5x06_ts_data *tsdata = data;
604 
605 	*mode = tsdata->factory_mode;
606 
607 	return 0;
608 };
609 
610 static int edt_ft5x06_debugfs_mode_set(void *data, u64 mode)
611 {
612 	struct edt_ft5x06_ts_data *tsdata = data;
613 	int retval = 0;
614 
615 	if (mode > 1)
616 		return -ERANGE;
617 
618 	mutex_lock(&tsdata->mutex);
619 
620 	if (mode != tsdata->factory_mode) {
621 		retval = mode ? edt_ft5x06_factory_mode(tsdata) :
622 				edt_ft5x06_work_mode(tsdata);
623 	}
624 
625 	mutex_unlock(&tsdata->mutex);
626 
627 	return retval;
628 };
629 
630 DEFINE_SIMPLE_ATTRIBUTE(debugfs_mode_fops, edt_ft5x06_debugfs_mode_get,
631 			edt_ft5x06_debugfs_mode_set, "%llu\n");
632 
633 static ssize_t edt_ft5x06_debugfs_raw_data_read(struct file *file,
634 				char __user *buf, size_t count, loff_t *off)
635 {
636 	struct edt_ft5x06_ts_data *tsdata = file->private_data;
637 	struct i2c_client *client = tsdata->client;
638 	int retries  = EDT_RAW_DATA_RETRIES;
639 	int val, i, error;
640 	size_t read = 0;
641 	int colbytes;
642 	char wrbuf[3];
643 	u8 *rdbuf;
644 
645 	if (*off < 0 || *off >= tsdata->raw_bufsize)
646 		return 0;
647 
648 	mutex_lock(&tsdata->mutex);
649 
650 	if (!tsdata->factory_mode || !tsdata->raw_buffer) {
651 		error = -EIO;
652 		goto out;
653 	}
654 
655 	error = edt_ft5x06_register_write(tsdata, 0x08, 0x01);
656 	if (error) {
657 		dev_dbg(&client->dev,
658 			"failed to write 0x08 register, error %d\n", error);
659 		goto out;
660 	}
661 
662 	do {
663 		msleep(EDT_RAW_DATA_DELAY);
664 		val = edt_ft5x06_register_read(tsdata, 0x08);
665 		if (val < 1)
666 			break;
667 	} while (--retries > 0);
668 
669 	if (val < 0) {
670 		error = val;
671 		dev_dbg(&client->dev,
672 			"failed to read 0x08 register, error %d\n", error);
673 		goto out;
674 	}
675 
676 	if (retries == 0) {
677 		dev_dbg(&client->dev,
678 			"timed out waiting for register to settle\n");
679 		error = -ETIMEDOUT;
680 		goto out;
681 	}
682 
683 	rdbuf = tsdata->raw_buffer;
684 	colbytes = tsdata->num_y * sizeof(u16);
685 
686 	wrbuf[0] = 0xf5;
687 	wrbuf[1] = 0x0e;
688 	for (i = 0; i < tsdata->num_x; i++) {
689 		wrbuf[2] = i;  /* column index */
690 		error = edt_ft5x06_ts_readwrite(tsdata->client,
691 						sizeof(wrbuf), wrbuf,
692 						colbytes, rdbuf);
693 		if (error)
694 			goto out;
695 
696 		rdbuf += colbytes;
697 	}
698 
699 	read = min_t(size_t, count, tsdata->raw_bufsize - *off);
700 	if (copy_to_user(buf, tsdata->raw_buffer + *off, read)) {
701 		error = -EFAULT;
702 		goto out;
703 	}
704 
705 	*off += read;
706 out:
707 	mutex_unlock(&tsdata->mutex);
708 	return error ?: read;
709 };
710 
711 static const struct file_operations debugfs_raw_data_fops = {
712 	.open = simple_open,
713 	.read = edt_ft5x06_debugfs_raw_data_read,
714 };
715 
716 static void
717 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
718 			      const char *debugfs_name)
719 {
720 	tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
721 	if (!tsdata->debug_dir)
722 		return;
723 
724 	debugfs_create_u16("num_x", S_IRUSR, tsdata->debug_dir, &tsdata->num_x);
725 	debugfs_create_u16("num_y", S_IRUSR, tsdata->debug_dir, &tsdata->num_y);
726 
727 	debugfs_create_file("mode", S_IRUSR | S_IWUSR,
728 			    tsdata->debug_dir, tsdata, &debugfs_mode_fops);
729 	debugfs_create_file("raw_data", S_IRUSR,
730 			    tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
731 }
732 
733 static void
734 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
735 {
736 	if (tsdata->debug_dir)
737 		debugfs_remove_recursive(tsdata->debug_dir);
738 	kfree(tsdata->raw_buffer);
739 }
740 
741 #else
742 
743 static inline void
744 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
745 			      const char *debugfs_name)
746 {
747 }
748 
749 static inline void
750 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
751 {
752 }
753 
754 #endif /* CONFIG_DEBUGFS */
755 
756 static int edt_ft5x06_ts_reset(struct i2c_client *client,
757 			struct edt_ft5x06_ts_data *tsdata)
758 {
759 	int error;
760 
761 	if (gpio_is_valid(tsdata->wake_pin)) {
762 		error = devm_gpio_request_one(&client->dev,
763 					tsdata->wake_pin, GPIOF_OUT_INIT_LOW,
764 					"edt-ft5x06 wake");
765 		if (error) {
766 			dev_err(&client->dev,
767 				"Failed to request GPIO %d as wake pin, error %d\n",
768 				tsdata->wake_pin, error);
769 			return error;
770 		}
771 
772 		msleep(5);
773 		gpio_set_value(tsdata->wake_pin, 1);
774 	}
775 	if (gpio_is_valid(tsdata->reset_pin)) {
776 		/* this pulls reset down, enabling the low active reset */
777 		error = devm_gpio_request_one(&client->dev,
778 					tsdata->reset_pin, GPIOF_OUT_INIT_LOW,
779 					"edt-ft5x06 reset");
780 		if (error) {
781 			dev_err(&client->dev,
782 				"Failed to request GPIO %d as reset pin, error %d\n",
783 				tsdata->reset_pin, error);
784 			return error;
785 		}
786 
787 		msleep(5);
788 		gpio_set_value(tsdata->reset_pin, 1);
789 		msleep(300);
790 	}
791 
792 	return 0;
793 }
794 
795 static int edt_ft5x06_ts_identify(struct i2c_client *client,
796 					struct edt_ft5x06_ts_data *tsdata,
797 					char *fw_version)
798 {
799 	u8 rdbuf[EDT_NAME_LEN];
800 	char *p;
801 	int error;
802 	char *model_name = tsdata->name;
803 
804 	/* see what we find if we assume it is a M06 *
805 	 * if we get less than EDT_NAME_LEN, we don't want
806 	 * to have garbage in there
807 	 */
808 	memset(rdbuf, 0, sizeof(rdbuf));
809 	error = edt_ft5x06_ts_readwrite(client, 1, "\xbb",
810 					EDT_NAME_LEN - 1, rdbuf);
811 	if (error)
812 		return error;
813 
814 	/* if we find something consistent, stay with that assumption
815 	 * at least M09 won't send 3 bytes here
816 	 */
817 	if (!(strnicmp(rdbuf + 1, "EP0", 3))) {
818 		tsdata->version = M06;
819 
820 		/* remove last '$' end marker */
821 		rdbuf[EDT_NAME_LEN - 1] = '\0';
822 		if (rdbuf[EDT_NAME_LEN - 2] == '$')
823 			rdbuf[EDT_NAME_LEN - 2] = '\0';
824 
825 		/* look for Model/Version separator */
826 		p = strchr(rdbuf, '*');
827 		if (p)
828 			*p++ = '\0';
829 		strlcpy(model_name, rdbuf + 1, EDT_NAME_LEN);
830 		strlcpy(fw_version, p ? p : "", EDT_NAME_LEN);
831 	} else {
832 		/* since there are only two versions around (M06, M09) */
833 		tsdata->version = M09;
834 
835 		error = edt_ft5x06_ts_readwrite(client, 1, "\xA6",
836 						2, rdbuf);
837 		if (error)
838 			return error;
839 
840 		strlcpy(fw_version, rdbuf, 2);
841 
842 		error = edt_ft5x06_ts_readwrite(client, 1, "\xA8",
843 						1, rdbuf);
844 		if (error)
845 			return error;
846 
847 		snprintf(model_name, EDT_NAME_LEN, "EP0%i%i0M09",
848 			rdbuf[0] >> 4, rdbuf[0] & 0x0F);
849 	}
850 
851 	return 0;
852 }
853 
854 #define EDT_ATTR_CHECKSET(name, reg) \
855 	if (pdata->name >= edt_ft5x06_attr_##name.limit_low &&		\
856 	    pdata->name <= edt_ft5x06_attr_##name.limit_high)		\
857 		edt_ft5x06_register_write(tsdata, reg, pdata->name)
858 
859 #define EDT_GET_PROP(name, reg) {				\
860 	u32 val;						\
861 	if (of_property_read_u32(np, #name, &val) == 0)		\
862 		edt_ft5x06_register_write(tsdata, reg, val);	\
863 }
864 
865 static void edt_ft5x06_ts_get_dt_defaults(struct device_node *np,
866 					struct edt_ft5x06_ts_data *tsdata)
867 {
868 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
869 
870 	EDT_GET_PROP(threshold, reg_addr->reg_threshold);
871 	EDT_GET_PROP(gain, reg_addr->reg_gain);
872 	EDT_GET_PROP(offset, reg_addr->reg_offset);
873 }
874 
875 static void
876 edt_ft5x06_ts_get_defaults(struct edt_ft5x06_ts_data *tsdata,
877 			   const struct edt_ft5x06_platform_data *pdata)
878 {
879 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
880 
881 	if (!pdata->use_parameters)
882 		return;
883 
884 	/* pick up defaults from the platform data */
885 	EDT_ATTR_CHECKSET(threshold, reg_addr->reg_threshold);
886 	EDT_ATTR_CHECKSET(gain, reg_addr->reg_gain);
887 	EDT_ATTR_CHECKSET(offset, reg_addr->reg_offset);
888 	if (reg_addr->reg_report_rate != NO_REGISTER)
889 		EDT_ATTR_CHECKSET(report_rate, reg_addr->reg_report_rate);
890 }
891 
892 static void
893 edt_ft5x06_ts_get_parameters(struct edt_ft5x06_ts_data *tsdata)
894 {
895 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
896 
897 	tsdata->threshold = edt_ft5x06_register_read(tsdata,
898 						     reg_addr->reg_threshold);
899 	tsdata->gain = edt_ft5x06_register_read(tsdata, reg_addr->reg_gain);
900 	tsdata->offset = edt_ft5x06_register_read(tsdata, reg_addr->reg_offset);
901 	if (reg_addr->reg_report_rate != NO_REGISTER)
902 		tsdata->report_rate = edt_ft5x06_register_read(tsdata,
903 						reg_addr->reg_report_rate);
904 	tsdata->num_x = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_x);
905 	tsdata->num_y = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_y);
906 }
907 
908 static void
909 edt_ft5x06_ts_set_regs(struct edt_ft5x06_ts_data *tsdata)
910 {
911 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
912 
913 	switch (tsdata->version) {
914 	case M06:
915 		reg_addr->reg_threshold = WORK_REGISTER_THRESHOLD;
916 		reg_addr->reg_report_rate = WORK_REGISTER_REPORT_RATE;
917 		reg_addr->reg_gain = WORK_REGISTER_GAIN;
918 		reg_addr->reg_offset = WORK_REGISTER_OFFSET;
919 		reg_addr->reg_num_x = WORK_REGISTER_NUM_X;
920 		reg_addr->reg_num_y = WORK_REGISTER_NUM_Y;
921 		break;
922 
923 	case M09:
924 		reg_addr->reg_threshold = M09_REGISTER_THRESHOLD;
925 		reg_addr->reg_gain = M09_REGISTER_GAIN;
926 		reg_addr->reg_offset = M09_REGISTER_OFFSET;
927 		reg_addr->reg_num_x = M09_REGISTER_NUM_X;
928 		reg_addr->reg_num_y = M09_REGISTER_NUM_Y;
929 		break;
930 	}
931 }
932 
933 #ifdef CONFIG_OF
934 static int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
935 				struct edt_ft5x06_ts_data *tsdata)
936 {
937 	struct device_node *np = dev->of_node;
938 
939 	/*
940 	 * irq_pin is not needed for DT setup.
941 	 * irq is associated via 'interrupts' property in DT
942 	 */
943 	tsdata->irq_pin = -EINVAL;
944 	tsdata->reset_pin = of_get_named_gpio(np, "reset-gpios", 0);
945 	tsdata->wake_pin = of_get_named_gpio(np, "wake-gpios", 0);
946 
947 	return 0;
948 }
949 #else
950 static inline int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
951 					struct edt_ft5x06_ts_data *tsdata)
952 {
953 	return -ENODEV;
954 }
955 #endif
956 
957 static int edt_ft5x06_ts_probe(struct i2c_client *client,
958 					 const struct i2c_device_id *id)
959 {
960 	const struct edt_ft5x06_platform_data *pdata =
961 						dev_get_platdata(&client->dev);
962 	struct edt_ft5x06_ts_data *tsdata;
963 	struct input_dev *input;
964 	int error;
965 	char fw_version[EDT_NAME_LEN];
966 
967 	dev_dbg(&client->dev, "probing for EDT FT5x06 I2C\n");
968 
969 	tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
970 	if (!tsdata) {
971 		dev_err(&client->dev, "failed to allocate driver data.\n");
972 		return -ENOMEM;
973 	}
974 
975 	if (!pdata) {
976 		error = edt_ft5x06_i2c_ts_probe_dt(&client->dev, tsdata);
977 		if (error) {
978 			dev_err(&client->dev,
979 				"DT probe failed and no platform data present\n");
980 			return error;
981 		}
982 	} else {
983 		tsdata->reset_pin = pdata->reset_pin;
984 		tsdata->irq_pin = pdata->irq_pin;
985 		tsdata->wake_pin = -EINVAL;
986 	}
987 
988 	error = edt_ft5x06_ts_reset(client, tsdata);
989 	if (error)
990 		return error;
991 
992 	if (gpio_is_valid(tsdata->irq_pin)) {
993 		error = devm_gpio_request_one(&client->dev, tsdata->irq_pin,
994 					GPIOF_IN, "edt-ft5x06 irq");
995 		if (error) {
996 			dev_err(&client->dev,
997 				"Failed to request GPIO %d, error %d\n",
998 				tsdata->irq_pin, error);
999 			return error;
1000 		}
1001 	}
1002 
1003 	input = devm_input_allocate_device(&client->dev);
1004 	if (!input) {
1005 		dev_err(&client->dev, "failed to allocate input device.\n");
1006 		return -ENOMEM;
1007 	}
1008 
1009 	mutex_init(&tsdata->mutex);
1010 	tsdata->client = client;
1011 	tsdata->input = input;
1012 	tsdata->factory_mode = false;
1013 
1014 	error = edt_ft5x06_ts_identify(client, tsdata, fw_version);
1015 	if (error) {
1016 		dev_err(&client->dev, "touchscreen probe failed\n");
1017 		return error;
1018 	}
1019 
1020 	edt_ft5x06_ts_set_regs(tsdata);
1021 
1022 	if (!pdata)
1023 		edt_ft5x06_ts_get_dt_defaults(client->dev.of_node, tsdata);
1024 	else
1025 		edt_ft5x06_ts_get_defaults(tsdata, pdata);
1026 
1027 	edt_ft5x06_ts_get_parameters(tsdata);
1028 
1029 	dev_dbg(&client->dev,
1030 		"Model \"%s\", Rev. \"%s\", %dx%d sensors\n",
1031 		tsdata->name, fw_version, tsdata->num_x, tsdata->num_y);
1032 
1033 	input->name = tsdata->name;
1034 	input->id.bustype = BUS_I2C;
1035 	input->dev.parent = &client->dev;
1036 
1037 	__set_bit(EV_SYN, input->evbit);
1038 	__set_bit(EV_KEY, input->evbit);
1039 	__set_bit(EV_ABS, input->evbit);
1040 	__set_bit(BTN_TOUCH, input->keybit);
1041 	input_set_abs_params(input, ABS_X, 0, tsdata->num_x * 64 - 1, 0, 0);
1042 	input_set_abs_params(input, ABS_Y, 0, tsdata->num_y * 64 - 1, 0, 0);
1043 	input_set_abs_params(input, ABS_MT_POSITION_X,
1044 			     0, tsdata->num_x * 64 - 1, 0, 0);
1045 	input_set_abs_params(input, ABS_MT_POSITION_Y,
1046 			     0, tsdata->num_y * 64 - 1, 0, 0);
1047 	error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, 0);
1048 	if (error) {
1049 		dev_err(&client->dev, "Unable to init MT slots.\n");
1050 		return error;
1051 	}
1052 
1053 	input_set_drvdata(input, tsdata);
1054 	i2c_set_clientdata(client, tsdata);
1055 
1056 	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
1057 					edt_ft5x06_ts_isr,
1058 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1059 					client->name, tsdata);
1060 	if (error) {
1061 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
1062 		return error;
1063 	}
1064 
1065 	error = sysfs_create_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1066 	if (error)
1067 		return error;
1068 
1069 	error = input_register_device(input);
1070 	if (error)
1071 		goto err_remove_attrs;
1072 
1073 	edt_ft5x06_ts_prepare_debugfs(tsdata, dev_driver_string(&client->dev));
1074 	device_init_wakeup(&client->dev, 1);
1075 
1076 	dev_dbg(&client->dev,
1077 		"EDT FT5x06 initialized: IRQ %d, WAKE pin %d, Reset pin %d.\n",
1078 		client->irq, tsdata->wake_pin, tsdata->reset_pin);
1079 
1080 	return 0;
1081 
1082 err_remove_attrs:
1083 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1084 	return error;
1085 }
1086 
1087 static int edt_ft5x06_ts_remove(struct i2c_client *client)
1088 {
1089 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
1090 
1091 	edt_ft5x06_ts_teardown_debugfs(tsdata);
1092 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1093 
1094 	return 0;
1095 }
1096 
1097 #ifdef CONFIG_PM_SLEEP
1098 static int edt_ft5x06_ts_suspend(struct device *dev)
1099 {
1100 	struct i2c_client *client = to_i2c_client(dev);
1101 
1102 	if (device_may_wakeup(dev))
1103 		enable_irq_wake(client->irq);
1104 
1105 	return 0;
1106 }
1107 
1108 static int edt_ft5x06_ts_resume(struct device *dev)
1109 {
1110 	struct i2c_client *client = to_i2c_client(dev);
1111 
1112 	if (device_may_wakeup(dev))
1113 		disable_irq_wake(client->irq);
1114 
1115 	return 0;
1116 }
1117 #endif
1118 
1119 static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
1120 			 edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
1121 
1122 static const struct i2c_device_id edt_ft5x06_ts_id[] = {
1123 	{ "edt-ft5x06", 0, },
1124 	{ /* sentinel */ }
1125 };
1126 MODULE_DEVICE_TABLE(i2c, edt_ft5x06_ts_id);
1127 
1128 #ifdef CONFIG_OF
1129 static const struct of_device_id edt_ft5x06_of_match[] = {
1130 	{ .compatible = "edt,edt-ft5206", },
1131 	{ .compatible = "edt,edt-ft5306", },
1132 	{ .compatible = "edt,edt-ft5406", },
1133 	{ /* sentinel */ }
1134 };
1135 MODULE_DEVICE_TABLE(of, edt_ft5x06_of_match);
1136 #endif
1137 
1138 static struct i2c_driver edt_ft5x06_ts_driver = {
1139 	.driver = {
1140 		.owner = THIS_MODULE,
1141 		.name = "edt_ft5x06",
1142 		.of_match_table = of_match_ptr(edt_ft5x06_of_match),
1143 		.pm = &edt_ft5x06_ts_pm_ops,
1144 	},
1145 	.id_table = edt_ft5x06_ts_id,
1146 	.probe    = edt_ft5x06_ts_probe,
1147 	.remove   = edt_ft5x06_ts_remove,
1148 };
1149 
1150 module_i2c_driver(edt_ft5x06_ts_driver);
1151 
1152 MODULE_AUTHOR("Simon Budig <simon.budig@kernelconcepts.de>");
1153 MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
1154 MODULE_LICENSE("GPL");
1155