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[2] = value;
266 		wrbuf[3] = wrbuf[0] ^ wrbuf[1] ^ wrbuf[2];
267 		return edt_ft5x06_ts_readwrite(tsdata->client, 4,
268 					wrbuf, 0, NULL);
269 	case M09:
270 		wrbuf[0] = addr;
271 		wrbuf[1] = value;
272 
273 		return edt_ft5x06_ts_readwrite(tsdata->client, 2,
274 					wrbuf, 0, NULL);
275 
276 	default:
277 		return -EINVAL;
278 	}
279 }
280 
281 static int edt_ft5x06_register_read(struct edt_ft5x06_ts_data *tsdata,
282 				    u8 addr)
283 {
284 	u8 wrbuf[2], rdbuf[2];
285 	int error;
286 
287 	switch (tsdata->version) {
288 	case M06:
289 		wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
290 		wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
291 		wrbuf[1] |= tsdata->factory_mode ? 0x80 : 0x40;
292 
293 		error = edt_ft5x06_ts_readwrite(tsdata->client, 2, wrbuf, 2,
294 						rdbuf);
295 		if (error)
296 			return error;
297 
298 		if ((wrbuf[0] ^ wrbuf[1] ^ rdbuf[0]) != rdbuf[1]) {
299 			dev_err(&tsdata->client->dev,
300 				"crc error: 0x%02x expected, got 0x%02x\n",
301 				wrbuf[0] ^ wrbuf[1] ^ rdbuf[0],
302 				rdbuf[1]);
303 			return -EIO;
304 		}
305 		break;
306 
307 	case M09:
308 		wrbuf[0] = addr;
309 		error = edt_ft5x06_ts_readwrite(tsdata->client, 1,
310 						wrbuf, 1, rdbuf);
311 		if (error)
312 			return error;
313 		break;
314 
315 	default:
316 		return -EINVAL;
317 	}
318 
319 	return rdbuf[0];
320 }
321 
322 struct edt_ft5x06_attribute {
323 	struct device_attribute dattr;
324 	size_t field_offset;
325 	u8 limit_low;
326 	u8 limit_high;
327 	u8 addr_m06;
328 	u8 addr_m09;
329 };
330 
331 #define EDT_ATTR(_field, _mode, _addr_m06, _addr_m09,			\
332 		_limit_low, _limit_high)				\
333 	struct edt_ft5x06_attribute edt_ft5x06_attr_##_field = {	\
334 		.dattr = __ATTR(_field, _mode,				\
335 				edt_ft5x06_setting_show,		\
336 				edt_ft5x06_setting_store),		\
337 		.field_offset = offsetof(struct edt_ft5x06_ts_data, _field), \
338 		.addr_m06 = _addr_m06,					\
339 		.addr_m09 = _addr_m09,					\
340 		.limit_low = _limit_low,				\
341 		.limit_high = _limit_high,				\
342 	}
343 
344 static ssize_t edt_ft5x06_setting_show(struct device *dev,
345 				       struct device_attribute *dattr,
346 				       char *buf)
347 {
348 	struct i2c_client *client = to_i2c_client(dev);
349 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
350 	struct edt_ft5x06_attribute *attr =
351 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
352 	u8 *field = (u8 *)tsdata + attr->field_offset;
353 	int val;
354 	size_t count = 0;
355 	int error = 0;
356 	u8 addr;
357 
358 	mutex_lock(&tsdata->mutex);
359 
360 	if (tsdata->factory_mode) {
361 		error = -EIO;
362 		goto out;
363 	}
364 
365 	switch (tsdata->version) {
366 	case M06:
367 		addr = attr->addr_m06;
368 		break;
369 
370 	case M09:
371 		addr = attr->addr_m09;
372 		break;
373 
374 	default:
375 		error = -ENODEV;
376 		goto out;
377 	}
378 
379 	if (addr != NO_REGISTER) {
380 		val = edt_ft5x06_register_read(tsdata, addr);
381 		if (val < 0) {
382 			error = val;
383 			dev_err(&tsdata->client->dev,
384 				"Failed to fetch attribute %s, error %d\n",
385 				dattr->attr.name, error);
386 			goto out;
387 		}
388 	} else {
389 		val = *field;
390 	}
391 
392 	if (val != *field) {
393 		dev_warn(&tsdata->client->dev,
394 			 "%s: read (%d) and stored value (%d) differ\n",
395 			 dattr->attr.name, val, *field);
396 		*field = val;
397 	}
398 
399 	count = scnprintf(buf, PAGE_SIZE, "%d\n", val);
400 out:
401 	mutex_unlock(&tsdata->mutex);
402 	return error ?: count;
403 }
404 
405 static ssize_t edt_ft5x06_setting_store(struct device *dev,
406 					struct device_attribute *dattr,
407 					const char *buf, size_t count)
408 {
409 	struct i2c_client *client = to_i2c_client(dev);
410 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
411 	struct edt_ft5x06_attribute *attr =
412 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
413 	u8 *field = (u8 *)tsdata + attr->field_offset;
414 	unsigned int val;
415 	int error;
416 	u8 addr;
417 
418 	mutex_lock(&tsdata->mutex);
419 
420 	if (tsdata->factory_mode) {
421 		error = -EIO;
422 		goto out;
423 	}
424 
425 	error = kstrtouint(buf, 0, &val);
426 	if (error)
427 		goto out;
428 
429 	if (val < attr->limit_low || val > attr->limit_high) {
430 		error = -ERANGE;
431 		goto out;
432 	}
433 
434 	switch (tsdata->version) {
435 	case M06:
436 		addr = attr->addr_m06;
437 		break;
438 
439 	case M09:
440 		addr = attr->addr_m09;
441 		break;
442 
443 	default:
444 		error = -ENODEV;
445 		goto out;
446 	}
447 
448 	if (addr != NO_REGISTER) {
449 		error = edt_ft5x06_register_write(tsdata, addr, val);
450 		if (error) {
451 			dev_err(&tsdata->client->dev,
452 				"Failed to update attribute %s, error: %d\n",
453 				dattr->attr.name, error);
454 			goto out;
455 		}
456 	}
457 	*field = val;
458 
459 out:
460 	mutex_unlock(&tsdata->mutex);
461 	return error ?: count;
462 }
463 
464 static EDT_ATTR(gain, S_IWUSR | S_IRUGO, WORK_REGISTER_GAIN,
465 		M09_REGISTER_GAIN, 0, 31);
466 static EDT_ATTR(offset, S_IWUSR | S_IRUGO, WORK_REGISTER_OFFSET,
467 		M09_REGISTER_OFFSET, 0, 31);
468 static EDT_ATTR(threshold, S_IWUSR | S_IRUGO, WORK_REGISTER_THRESHOLD,
469 		M09_REGISTER_THRESHOLD, 20, 80);
470 static EDT_ATTR(report_rate, S_IWUSR | S_IRUGO, WORK_REGISTER_REPORT_RATE,
471 		NO_REGISTER, 3, 14);
472 
473 static struct attribute *edt_ft5x06_attrs[] = {
474 	&edt_ft5x06_attr_gain.dattr.attr,
475 	&edt_ft5x06_attr_offset.dattr.attr,
476 	&edt_ft5x06_attr_threshold.dattr.attr,
477 	&edt_ft5x06_attr_report_rate.dattr.attr,
478 	NULL
479 };
480 
481 static const struct attribute_group edt_ft5x06_attr_group = {
482 	.attrs = edt_ft5x06_attrs,
483 };
484 
485 #ifdef CONFIG_DEBUG_FS
486 static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
487 {
488 	struct i2c_client *client = tsdata->client;
489 	int retries = EDT_SWITCH_MODE_RETRIES;
490 	int ret;
491 	int error;
492 
493 	disable_irq(client->irq);
494 
495 	if (!tsdata->raw_buffer) {
496 		tsdata->raw_bufsize = tsdata->num_x * tsdata->num_y *
497 				      sizeof(u16);
498 		tsdata->raw_buffer = kzalloc(tsdata->raw_bufsize, GFP_KERNEL);
499 		if (!tsdata->raw_buffer) {
500 			error = -ENOMEM;
501 			goto err_out;
502 		}
503 	}
504 
505 	/* mode register is 0x3c when in the work mode */
506 	if (tsdata->version == M09)
507 		goto m09_out;
508 
509 	error = edt_ft5x06_register_write(tsdata, WORK_REGISTER_OPMODE, 0x03);
510 	if (error) {
511 		dev_err(&client->dev,
512 			"failed to switch to factory mode, error %d\n", error);
513 		goto err_out;
514 	}
515 
516 	tsdata->factory_mode = true;
517 	do {
518 		mdelay(EDT_SWITCH_MODE_DELAY);
519 		/* mode register is 0x01 when in factory mode */
520 		ret = edt_ft5x06_register_read(tsdata, FACTORY_REGISTER_OPMODE);
521 		if (ret == 0x03)
522 			break;
523 	} while (--retries > 0);
524 
525 	if (retries == 0) {
526 		dev_err(&client->dev, "not in factory mode after %dms.\n",
527 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
528 		error = -EIO;
529 		goto err_out;
530 	}
531 
532 	return 0;
533 
534 err_out:
535 	kfree(tsdata->raw_buffer);
536 	tsdata->raw_buffer = NULL;
537 	tsdata->factory_mode = false;
538 	enable_irq(client->irq);
539 
540 	return error;
541 
542 m09_out:
543 	dev_err(&client->dev, "No factory mode support for M09\n");
544 	return -EINVAL;
545 
546 }
547 
548 static int edt_ft5x06_work_mode(struct edt_ft5x06_ts_data *tsdata)
549 {
550 	struct i2c_client *client = tsdata->client;
551 	int retries = EDT_SWITCH_MODE_RETRIES;
552 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
553 	int ret;
554 	int error;
555 
556 	/* mode register is 0x01 when in the factory mode */
557 	error = edt_ft5x06_register_write(tsdata, FACTORY_REGISTER_OPMODE, 0x1);
558 	if (error) {
559 		dev_err(&client->dev,
560 			"failed to switch to work mode, error: %d\n", error);
561 		return error;
562 	}
563 
564 	tsdata->factory_mode = false;
565 
566 	do {
567 		mdelay(EDT_SWITCH_MODE_DELAY);
568 		/* mode register is 0x01 when in factory mode */
569 		ret = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OPMODE);
570 		if (ret == 0x01)
571 			break;
572 	} while (--retries > 0);
573 
574 	if (retries == 0) {
575 		dev_err(&client->dev, "not in work mode after %dms.\n",
576 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
577 		tsdata->factory_mode = true;
578 		return -EIO;
579 	}
580 
581 	kfree(tsdata->raw_buffer);
582 	tsdata->raw_buffer = NULL;
583 
584 	/* restore parameters */
585 	edt_ft5x06_register_write(tsdata, reg_addr->reg_threshold,
586 				  tsdata->threshold);
587 	edt_ft5x06_register_write(tsdata, reg_addr->reg_gain,
588 				  tsdata->gain);
589 	edt_ft5x06_register_write(tsdata, reg_addr->reg_offset,
590 				  tsdata->offset);
591 	if (reg_addr->reg_report_rate)
592 		edt_ft5x06_register_write(tsdata, reg_addr->reg_report_rate,
593 				  tsdata->report_rate);
594 
595 	enable_irq(client->irq);
596 
597 	return 0;
598 }
599 
600 static int edt_ft5x06_debugfs_mode_get(void *data, u64 *mode)
601 {
602 	struct edt_ft5x06_ts_data *tsdata = data;
603 
604 	*mode = tsdata->factory_mode;
605 
606 	return 0;
607 };
608 
609 static int edt_ft5x06_debugfs_mode_set(void *data, u64 mode)
610 {
611 	struct edt_ft5x06_ts_data *tsdata = data;
612 	int retval = 0;
613 
614 	if (mode > 1)
615 		return -ERANGE;
616 
617 	mutex_lock(&tsdata->mutex);
618 
619 	if (mode != tsdata->factory_mode) {
620 		retval = mode ? edt_ft5x06_factory_mode(tsdata) :
621 				edt_ft5x06_work_mode(tsdata);
622 	}
623 
624 	mutex_unlock(&tsdata->mutex);
625 
626 	return retval;
627 };
628 
629 DEFINE_SIMPLE_ATTRIBUTE(debugfs_mode_fops, edt_ft5x06_debugfs_mode_get,
630 			edt_ft5x06_debugfs_mode_set, "%llu\n");
631 
632 static ssize_t edt_ft5x06_debugfs_raw_data_read(struct file *file,
633 				char __user *buf, size_t count, loff_t *off)
634 {
635 	struct edt_ft5x06_ts_data *tsdata = file->private_data;
636 	struct i2c_client *client = tsdata->client;
637 	int retries  = EDT_RAW_DATA_RETRIES;
638 	int val, i, error;
639 	size_t read = 0;
640 	int colbytes;
641 	char wrbuf[3];
642 	u8 *rdbuf;
643 
644 	if (*off < 0 || *off >= tsdata->raw_bufsize)
645 		return 0;
646 
647 	mutex_lock(&tsdata->mutex);
648 
649 	if (!tsdata->factory_mode || !tsdata->raw_buffer) {
650 		error = -EIO;
651 		goto out;
652 	}
653 
654 	error = edt_ft5x06_register_write(tsdata, 0x08, 0x01);
655 	if (error) {
656 		dev_dbg(&client->dev,
657 			"failed to write 0x08 register, error %d\n", error);
658 		goto out;
659 	}
660 
661 	do {
662 		msleep(EDT_RAW_DATA_DELAY);
663 		val = edt_ft5x06_register_read(tsdata, 0x08);
664 		if (val < 1)
665 			break;
666 	} while (--retries > 0);
667 
668 	if (val < 0) {
669 		error = val;
670 		dev_dbg(&client->dev,
671 			"failed to read 0x08 register, error %d\n", error);
672 		goto out;
673 	}
674 
675 	if (retries == 0) {
676 		dev_dbg(&client->dev,
677 			"timed out waiting for register to settle\n");
678 		error = -ETIMEDOUT;
679 		goto out;
680 	}
681 
682 	rdbuf = tsdata->raw_buffer;
683 	colbytes = tsdata->num_y * sizeof(u16);
684 
685 	wrbuf[0] = 0xf5;
686 	wrbuf[1] = 0x0e;
687 	for (i = 0; i < tsdata->num_x; i++) {
688 		wrbuf[2] = i;  /* column index */
689 		error = edt_ft5x06_ts_readwrite(tsdata->client,
690 						sizeof(wrbuf), wrbuf,
691 						colbytes, rdbuf);
692 		if (error)
693 			goto out;
694 
695 		rdbuf += colbytes;
696 	}
697 
698 	read = min_t(size_t, count, tsdata->raw_bufsize - *off);
699 	if (copy_to_user(buf, tsdata->raw_buffer + *off, read)) {
700 		error = -EFAULT;
701 		goto out;
702 	}
703 
704 	*off += read;
705 out:
706 	mutex_unlock(&tsdata->mutex);
707 	return error ?: read;
708 };
709 
710 static const struct file_operations debugfs_raw_data_fops = {
711 	.open = simple_open,
712 	.read = edt_ft5x06_debugfs_raw_data_read,
713 };
714 
715 static void
716 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
717 			      const char *debugfs_name)
718 {
719 	tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
720 	if (!tsdata->debug_dir)
721 		return;
722 
723 	debugfs_create_u16("num_x", S_IRUSR, tsdata->debug_dir, &tsdata->num_x);
724 	debugfs_create_u16("num_y", S_IRUSR, tsdata->debug_dir, &tsdata->num_y);
725 
726 	debugfs_create_file("mode", S_IRUSR | S_IWUSR,
727 			    tsdata->debug_dir, tsdata, &debugfs_mode_fops);
728 	debugfs_create_file("raw_data", S_IRUSR,
729 			    tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
730 }
731 
732 static void
733 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
734 {
735 	debugfs_remove_recursive(tsdata->debug_dir);
736 	kfree(tsdata->raw_buffer);
737 }
738 
739 #else
740 
741 static inline void
742 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
743 			      const char *debugfs_name)
744 {
745 }
746 
747 static inline void
748 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
749 {
750 }
751 
752 #endif /* CONFIG_DEBUGFS */
753 
754 static int edt_ft5x06_ts_reset(struct i2c_client *client,
755 			struct edt_ft5x06_ts_data *tsdata)
756 {
757 	int error;
758 
759 	if (gpio_is_valid(tsdata->wake_pin)) {
760 		error = devm_gpio_request_one(&client->dev,
761 					tsdata->wake_pin, GPIOF_OUT_INIT_LOW,
762 					"edt-ft5x06 wake");
763 		if (error) {
764 			dev_err(&client->dev,
765 				"Failed to request GPIO %d as wake pin, error %d\n",
766 				tsdata->wake_pin, error);
767 			return error;
768 		}
769 
770 		msleep(5);
771 		gpio_set_value(tsdata->wake_pin, 1);
772 	}
773 	if (gpio_is_valid(tsdata->reset_pin)) {
774 		/* this pulls reset down, enabling the low active reset */
775 		error = devm_gpio_request_one(&client->dev,
776 					tsdata->reset_pin, GPIOF_OUT_INIT_LOW,
777 					"edt-ft5x06 reset");
778 		if (error) {
779 			dev_err(&client->dev,
780 				"Failed to request GPIO %d as reset pin, error %d\n",
781 				tsdata->reset_pin, error);
782 			return error;
783 		}
784 
785 		msleep(5);
786 		gpio_set_value(tsdata->reset_pin, 1);
787 		msleep(300);
788 	}
789 
790 	return 0;
791 }
792 
793 static int edt_ft5x06_ts_identify(struct i2c_client *client,
794 					struct edt_ft5x06_ts_data *tsdata,
795 					char *fw_version)
796 {
797 	u8 rdbuf[EDT_NAME_LEN];
798 	char *p;
799 	int error;
800 	char *model_name = tsdata->name;
801 
802 	/* see what we find if we assume it is a M06 *
803 	 * if we get less than EDT_NAME_LEN, we don't want
804 	 * to have garbage in there
805 	 */
806 	memset(rdbuf, 0, sizeof(rdbuf));
807 	error = edt_ft5x06_ts_readwrite(client, 1, "\xbb",
808 					EDT_NAME_LEN - 1, rdbuf);
809 	if (error)
810 		return error;
811 
812 	/* if we find something consistent, stay with that assumption
813 	 * at least M09 won't send 3 bytes here
814 	 */
815 	if (!(strnicmp(rdbuf + 1, "EP0", 3))) {
816 		tsdata->version = M06;
817 
818 		/* remove last '$' end marker */
819 		rdbuf[EDT_NAME_LEN - 1] = '\0';
820 		if (rdbuf[EDT_NAME_LEN - 2] == '$')
821 			rdbuf[EDT_NAME_LEN - 2] = '\0';
822 
823 		/* look for Model/Version separator */
824 		p = strchr(rdbuf, '*');
825 		if (p)
826 			*p++ = '\0';
827 		strlcpy(model_name, rdbuf + 1, EDT_NAME_LEN);
828 		strlcpy(fw_version, p ? p : "", EDT_NAME_LEN);
829 	} else {
830 		/* since there are only two versions around (M06, M09) */
831 		tsdata->version = M09;
832 
833 		error = edt_ft5x06_ts_readwrite(client, 1, "\xA6",
834 						2, rdbuf);
835 		if (error)
836 			return error;
837 
838 		strlcpy(fw_version, rdbuf, 2);
839 
840 		error = edt_ft5x06_ts_readwrite(client, 1, "\xA8",
841 						1, rdbuf);
842 		if (error)
843 			return error;
844 
845 		snprintf(model_name, EDT_NAME_LEN, "EP0%i%i0M09",
846 			rdbuf[0] >> 4, rdbuf[0] & 0x0F);
847 	}
848 
849 	return 0;
850 }
851 
852 #define EDT_ATTR_CHECKSET(name, reg) \
853 	if (pdata->name >= edt_ft5x06_attr_##name.limit_low &&		\
854 	    pdata->name <= edt_ft5x06_attr_##name.limit_high)		\
855 		edt_ft5x06_register_write(tsdata, reg, pdata->name)
856 
857 #define EDT_GET_PROP(name, reg) {				\
858 	u32 val;						\
859 	if (of_property_read_u32(np, #name, &val) == 0)		\
860 		edt_ft5x06_register_write(tsdata, reg, val);	\
861 }
862 
863 static void edt_ft5x06_ts_get_dt_defaults(struct device_node *np,
864 					struct edt_ft5x06_ts_data *tsdata)
865 {
866 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
867 
868 	EDT_GET_PROP(threshold, reg_addr->reg_threshold);
869 	EDT_GET_PROP(gain, reg_addr->reg_gain);
870 	EDT_GET_PROP(offset, reg_addr->reg_offset);
871 }
872 
873 static void
874 edt_ft5x06_ts_get_defaults(struct edt_ft5x06_ts_data *tsdata,
875 			   const struct edt_ft5x06_platform_data *pdata)
876 {
877 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
878 
879 	if (!pdata->use_parameters)
880 		return;
881 
882 	/* pick up defaults from the platform data */
883 	EDT_ATTR_CHECKSET(threshold, reg_addr->reg_threshold);
884 	EDT_ATTR_CHECKSET(gain, reg_addr->reg_gain);
885 	EDT_ATTR_CHECKSET(offset, reg_addr->reg_offset);
886 	if (reg_addr->reg_report_rate != NO_REGISTER)
887 		EDT_ATTR_CHECKSET(report_rate, reg_addr->reg_report_rate);
888 }
889 
890 static void
891 edt_ft5x06_ts_get_parameters(struct edt_ft5x06_ts_data *tsdata)
892 {
893 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
894 
895 	tsdata->threshold = edt_ft5x06_register_read(tsdata,
896 						     reg_addr->reg_threshold);
897 	tsdata->gain = edt_ft5x06_register_read(tsdata, reg_addr->reg_gain);
898 	tsdata->offset = edt_ft5x06_register_read(tsdata, reg_addr->reg_offset);
899 	if (reg_addr->reg_report_rate != NO_REGISTER)
900 		tsdata->report_rate = edt_ft5x06_register_read(tsdata,
901 						reg_addr->reg_report_rate);
902 	tsdata->num_x = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_x);
903 	tsdata->num_y = edt_ft5x06_register_read(tsdata, reg_addr->reg_num_y);
904 }
905 
906 static void
907 edt_ft5x06_ts_set_regs(struct edt_ft5x06_ts_data *tsdata)
908 {
909 	struct edt_reg_addr *reg_addr = &tsdata->reg_addr;
910 
911 	switch (tsdata->version) {
912 	case M06:
913 		reg_addr->reg_threshold = WORK_REGISTER_THRESHOLD;
914 		reg_addr->reg_report_rate = WORK_REGISTER_REPORT_RATE;
915 		reg_addr->reg_gain = WORK_REGISTER_GAIN;
916 		reg_addr->reg_offset = WORK_REGISTER_OFFSET;
917 		reg_addr->reg_num_x = WORK_REGISTER_NUM_X;
918 		reg_addr->reg_num_y = WORK_REGISTER_NUM_Y;
919 		break;
920 
921 	case M09:
922 		reg_addr->reg_threshold = M09_REGISTER_THRESHOLD;
923 		reg_addr->reg_gain = M09_REGISTER_GAIN;
924 		reg_addr->reg_offset = M09_REGISTER_OFFSET;
925 		reg_addr->reg_num_x = M09_REGISTER_NUM_X;
926 		reg_addr->reg_num_y = M09_REGISTER_NUM_Y;
927 		break;
928 	}
929 }
930 
931 #ifdef CONFIG_OF
932 static int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
933 				struct edt_ft5x06_ts_data *tsdata)
934 {
935 	struct device_node *np = dev->of_node;
936 
937 	/*
938 	 * irq_pin is not needed for DT setup.
939 	 * irq is associated via 'interrupts' property in DT
940 	 */
941 	tsdata->irq_pin = -EINVAL;
942 	tsdata->reset_pin = of_get_named_gpio(np, "reset-gpios", 0);
943 	tsdata->wake_pin = of_get_named_gpio(np, "wake-gpios", 0);
944 
945 	return 0;
946 }
947 #else
948 static inline int edt_ft5x06_i2c_ts_probe_dt(struct device *dev,
949 					struct edt_ft5x06_ts_data *tsdata)
950 {
951 	return -ENODEV;
952 }
953 #endif
954 
955 static int edt_ft5x06_ts_probe(struct i2c_client *client,
956 					 const struct i2c_device_id *id)
957 {
958 	const struct edt_ft5x06_platform_data *pdata =
959 						dev_get_platdata(&client->dev);
960 	struct edt_ft5x06_ts_data *tsdata;
961 	struct input_dev *input;
962 	int error;
963 	char fw_version[EDT_NAME_LEN];
964 
965 	dev_dbg(&client->dev, "probing for EDT FT5x06 I2C\n");
966 
967 	tsdata = devm_kzalloc(&client->dev, sizeof(*tsdata), GFP_KERNEL);
968 	if (!tsdata) {
969 		dev_err(&client->dev, "failed to allocate driver data.\n");
970 		return -ENOMEM;
971 	}
972 
973 	if (!pdata) {
974 		error = edt_ft5x06_i2c_ts_probe_dt(&client->dev, tsdata);
975 		if (error) {
976 			dev_err(&client->dev,
977 				"DT probe failed and no platform data present\n");
978 			return error;
979 		}
980 	} else {
981 		tsdata->reset_pin = pdata->reset_pin;
982 		tsdata->irq_pin = pdata->irq_pin;
983 		tsdata->wake_pin = -EINVAL;
984 	}
985 
986 	error = edt_ft5x06_ts_reset(client, tsdata);
987 	if (error)
988 		return error;
989 
990 	if (gpio_is_valid(tsdata->irq_pin)) {
991 		error = devm_gpio_request_one(&client->dev, tsdata->irq_pin,
992 					GPIOF_IN, "edt-ft5x06 irq");
993 		if (error) {
994 			dev_err(&client->dev,
995 				"Failed to request GPIO %d, error %d\n",
996 				tsdata->irq_pin, error);
997 			return error;
998 		}
999 	}
1000 
1001 	input = devm_input_allocate_device(&client->dev);
1002 	if (!input) {
1003 		dev_err(&client->dev, "failed to allocate input device.\n");
1004 		return -ENOMEM;
1005 	}
1006 
1007 	mutex_init(&tsdata->mutex);
1008 	tsdata->client = client;
1009 	tsdata->input = input;
1010 	tsdata->factory_mode = false;
1011 
1012 	error = edt_ft5x06_ts_identify(client, tsdata, fw_version);
1013 	if (error) {
1014 		dev_err(&client->dev, "touchscreen probe failed\n");
1015 		return error;
1016 	}
1017 
1018 	edt_ft5x06_ts_set_regs(tsdata);
1019 
1020 	if (!pdata)
1021 		edt_ft5x06_ts_get_dt_defaults(client->dev.of_node, tsdata);
1022 	else
1023 		edt_ft5x06_ts_get_defaults(tsdata, pdata);
1024 
1025 	edt_ft5x06_ts_get_parameters(tsdata);
1026 
1027 	dev_dbg(&client->dev,
1028 		"Model \"%s\", Rev. \"%s\", %dx%d sensors\n",
1029 		tsdata->name, fw_version, tsdata->num_x, tsdata->num_y);
1030 
1031 	input->name = tsdata->name;
1032 	input->id.bustype = BUS_I2C;
1033 	input->dev.parent = &client->dev;
1034 
1035 	__set_bit(EV_SYN, input->evbit);
1036 	__set_bit(EV_KEY, input->evbit);
1037 	__set_bit(EV_ABS, input->evbit);
1038 	__set_bit(BTN_TOUCH, input->keybit);
1039 	input_set_abs_params(input, ABS_X, 0, tsdata->num_x * 64 - 1, 0, 0);
1040 	input_set_abs_params(input, ABS_Y, 0, tsdata->num_y * 64 - 1, 0, 0);
1041 	input_set_abs_params(input, ABS_MT_POSITION_X,
1042 			     0, tsdata->num_x * 64 - 1, 0, 0);
1043 	input_set_abs_params(input, ABS_MT_POSITION_Y,
1044 			     0, tsdata->num_y * 64 - 1, 0, 0);
1045 	error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, 0);
1046 	if (error) {
1047 		dev_err(&client->dev, "Unable to init MT slots.\n");
1048 		return error;
1049 	}
1050 
1051 	input_set_drvdata(input, tsdata);
1052 	i2c_set_clientdata(client, tsdata);
1053 
1054 	error = devm_request_threaded_irq(&client->dev, client->irq, NULL,
1055 					edt_ft5x06_ts_isr,
1056 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
1057 					client->name, tsdata);
1058 	if (error) {
1059 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
1060 		return error;
1061 	}
1062 
1063 	error = sysfs_create_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1064 	if (error)
1065 		return error;
1066 
1067 	error = input_register_device(input);
1068 	if (error)
1069 		goto err_remove_attrs;
1070 
1071 	edt_ft5x06_ts_prepare_debugfs(tsdata, dev_driver_string(&client->dev));
1072 	device_init_wakeup(&client->dev, 1);
1073 
1074 	dev_dbg(&client->dev,
1075 		"EDT FT5x06 initialized: IRQ %d, WAKE pin %d, Reset pin %d.\n",
1076 		client->irq, tsdata->wake_pin, tsdata->reset_pin);
1077 
1078 	return 0;
1079 
1080 err_remove_attrs:
1081 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1082 	return error;
1083 }
1084 
1085 static int edt_ft5x06_ts_remove(struct i2c_client *client)
1086 {
1087 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
1088 
1089 	edt_ft5x06_ts_teardown_debugfs(tsdata);
1090 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
1091 
1092 	return 0;
1093 }
1094 
1095 #ifdef CONFIG_PM_SLEEP
1096 static int edt_ft5x06_ts_suspend(struct device *dev)
1097 {
1098 	struct i2c_client *client = to_i2c_client(dev);
1099 
1100 	if (device_may_wakeup(dev))
1101 		enable_irq_wake(client->irq);
1102 
1103 	return 0;
1104 }
1105 
1106 static int edt_ft5x06_ts_resume(struct device *dev)
1107 {
1108 	struct i2c_client *client = to_i2c_client(dev);
1109 
1110 	if (device_may_wakeup(dev))
1111 		disable_irq_wake(client->irq);
1112 
1113 	return 0;
1114 }
1115 #endif
1116 
1117 static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
1118 			 edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
1119 
1120 static const struct i2c_device_id edt_ft5x06_ts_id[] = {
1121 	{ "edt-ft5x06", 0, },
1122 	{ /* sentinel */ }
1123 };
1124 MODULE_DEVICE_TABLE(i2c, edt_ft5x06_ts_id);
1125 
1126 #ifdef CONFIG_OF
1127 static const struct of_device_id edt_ft5x06_of_match[] = {
1128 	{ .compatible = "edt,edt-ft5206", },
1129 	{ .compatible = "edt,edt-ft5306", },
1130 	{ .compatible = "edt,edt-ft5406", },
1131 	{ /* sentinel */ }
1132 };
1133 MODULE_DEVICE_TABLE(of, edt_ft5x06_of_match);
1134 #endif
1135 
1136 static struct i2c_driver edt_ft5x06_ts_driver = {
1137 	.driver = {
1138 		.owner = THIS_MODULE,
1139 		.name = "edt_ft5x06",
1140 		.of_match_table = of_match_ptr(edt_ft5x06_of_match),
1141 		.pm = &edt_ft5x06_ts_pm_ops,
1142 	},
1143 	.id_table = edt_ft5x06_ts_id,
1144 	.probe    = edt_ft5x06_ts_probe,
1145 	.remove   = edt_ft5x06_ts_remove,
1146 };
1147 
1148 module_i2c_driver(edt_ft5x06_ts_driver);
1149 
1150 MODULE_AUTHOR("Simon Budig <simon.budig@kernelconcepts.de>");
1151 MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
1152 MODULE_LICENSE("GPL");
1153