xref: /linux/drivers/input/touchscreen/edt-ft5x06.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * Copyright (C) 2012 Simon Budig, <simon.budig@kernelconcepts.de>
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this library; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
16  */
17 
18 /*
19  * This is a driver for the EDT "Polytouch" family of touch controllers
20  * based on the FocalTech FT5x06 line of chips.
21  *
22  * Development of this driver has been sponsored by Glyn:
23  *    http://www.glyn.com/Products/Displays
24  */
25 
26 #include <linux/module.h>
27 #include <linux/ratelimit.h>
28 #include <linux/interrupt.h>
29 #include <linux/input.h>
30 #include <linux/i2c.h>
31 #include <linux/uaccess.h>
32 #include <linux/delay.h>
33 #include <linux/debugfs.h>
34 #include <linux/slab.h>
35 #include <linux/gpio.h>
36 #include <linux/input/mt.h>
37 #include <linux/input/edt-ft5x06.h>
38 
39 #define MAX_SUPPORT_POINTS		5
40 
41 #define WORK_REGISTER_THRESHOLD		0x00
42 #define WORK_REGISTER_REPORT_RATE	0x08
43 #define WORK_REGISTER_GAIN		0x30
44 #define WORK_REGISTER_OFFSET		0x31
45 #define WORK_REGISTER_NUM_X		0x33
46 #define WORK_REGISTER_NUM_Y		0x34
47 
48 #define WORK_REGISTER_OPMODE		0x3c
49 #define FACTORY_REGISTER_OPMODE		0x01
50 
51 #define TOUCH_EVENT_DOWN		0x00
52 #define TOUCH_EVENT_UP			0x01
53 #define TOUCH_EVENT_ON			0x02
54 #define TOUCH_EVENT_RESERVED		0x03
55 
56 #define EDT_NAME_LEN			23
57 #define EDT_SWITCH_MODE_RETRIES		10
58 #define EDT_SWITCH_MODE_DELAY		5 /* msec */
59 #define EDT_RAW_DATA_RETRIES		100
60 #define EDT_RAW_DATA_DELAY		1 /* msec */
61 
62 struct edt_ft5x06_ts_data {
63 	struct i2c_client *client;
64 	struct input_dev *input;
65 	u16 num_x;
66 	u16 num_y;
67 
68 #if defined(CONFIG_DEBUG_FS)
69 	struct dentry *debug_dir;
70 	u8 *raw_buffer;
71 	size_t raw_bufsize;
72 #endif
73 
74 	struct mutex mutex;
75 	bool factory_mode;
76 	int threshold;
77 	int gain;
78 	int offset;
79 	int report_rate;
80 
81 	char name[EDT_NAME_LEN];
82 };
83 
84 static int edt_ft5x06_ts_readwrite(struct i2c_client *client,
85 				   u16 wr_len, u8 *wr_buf,
86 				   u16 rd_len, u8 *rd_buf)
87 {
88 	struct i2c_msg wrmsg[2];
89 	int i = 0;
90 	int ret;
91 
92 	if (wr_len) {
93 		wrmsg[i].addr  = client->addr;
94 		wrmsg[i].flags = 0;
95 		wrmsg[i].len = wr_len;
96 		wrmsg[i].buf = wr_buf;
97 		i++;
98 	}
99 	if (rd_len) {
100 		wrmsg[i].addr  = client->addr;
101 		wrmsg[i].flags = I2C_M_RD;
102 		wrmsg[i].len = rd_len;
103 		wrmsg[i].buf = rd_buf;
104 		i++;
105 	}
106 
107 	ret = i2c_transfer(client->adapter, wrmsg, i);
108 	if (ret < 0)
109 		return ret;
110 	if (ret != i)
111 		return -EIO;
112 
113 	return 0;
114 }
115 
116 static bool edt_ft5x06_ts_check_crc(struct edt_ft5x06_ts_data *tsdata,
117 				    u8 *buf, int buflen)
118 {
119 	int i;
120 	u8 crc = 0;
121 
122 	for (i = 0; i < buflen - 1; i++)
123 		crc ^= buf[i];
124 
125 	if (crc != buf[buflen-1]) {
126 		dev_err_ratelimited(&tsdata->client->dev,
127 				    "crc error: 0x%02x expected, got 0x%02x\n",
128 				    crc, buf[buflen-1]);
129 		return false;
130 	}
131 
132 	return true;
133 }
134 
135 static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
136 {
137 	struct edt_ft5x06_ts_data *tsdata = dev_id;
138 	struct device *dev = &tsdata->client->dev;
139 	u8 cmd = 0xf9;
140 	u8 rdbuf[26];
141 	int i, type, x, y, id;
142 	int error;
143 
144 	memset(rdbuf, 0, sizeof(rdbuf));
145 
146 	error = edt_ft5x06_ts_readwrite(tsdata->client,
147 					sizeof(cmd), &cmd,
148 					sizeof(rdbuf), rdbuf);
149 	if (error) {
150 		dev_err_ratelimited(dev, "Unable to fetch data, error: %d\n",
151 				    error);
152 		goto out;
153 	}
154 
155 	if (rdbuf[0] != 0xaa || rdbuf[1] != 0xaa || rdbuf[2] != 26) {
156 		dev_err_ratelimited(dev, "Unexpected header: %02x%02x%02x!\n",
157 				    rdbuf[0], rdbuf[1], rdbuf[2]);
158 		goto out;
159 	}
160 
161 	if (!edt_ft5x06_ts_check_crc(tsdata, rdbuf, 26))
162 		goto out;
163 
164 	for (i = 0; i < MAX_SUPPORT_POINTS; i++) {
165 		u8 *buf = &rdbuf[i * 4 + 5];
166 		bool down;
167 
168 		type = buf[0] >> 6;
169 		/* ignore Reserved events */
170 		if (type == TOUCH_EVENT_RESERVED)
171 			continue;
172 
173 		x = ((buf[0] << 8) | buf[1]) & 0x0fff;
174 		y = ((buf[2] << 8) | buf[3]) & 0x0fff;
175 		id = (buf[2] >> 4) & 0x0f;
176 		down = (type != TOUCH_EVENT_UP);
177 
178 		input_mt_slot(tsdata->input, id);
179 		input_mt_report_slot_state(tsdata->input, MT_TOOL_FINGER, down);
180 
181 		if (!down)
182 			continue;
183 
184 		input_report_abs(tsdata->input, ABS_MT_POSITION_X, x);
185 		input_report_abs(tsdata->input, ABS_MT_POSITION_Y, y);
186 	}
187 
188 	input_mt_report_pointer_emulation(tsdata->input, true);
189 	input_sync(tsdata->input);
190 
191 out:
192 	return IRQ_HANDLED;
193 }
194 
195 static int edt_ft5x06_register_write(struct edt_ft5x06_ts_data *tsdata,
196 				     u8 addr, u8 value)
197 {
198 	u8 wrbuf[4];
199 
200 	wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
201 	wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
202 	wrbuf[2] = value;
203 	wrbuf[3] = wrbuf[0] ^ wrbuf[1] ^ wrbuf[2];
204 
205 	return edt_ft5x06_ts_readwrite(tsdata->client, 4, wrbuf, 0, NULL);
206 }
207 
208 static int edt_ft5x06_register_read(struct edt_ft5x06_ts_data *tsdata,
209 				    u8 addr)
210 {
211 	u8 wrbuf[2], rdbuf[2];
212 	int error;
213 
214 	wrbuf[0] = tsdata->factory_mode ? 0xf3 : 0xfc;
215 	wrbuf[1] = tsdata->factory_mode ? addr & 0x7f : addr & 0x3f;
216 	wrbuf[1] |= tsdata->factory_mode ? 0x80 : 0x40;
217 
218 	error = edt_ft5x06_ts_readwrite(tsdata->client, 2, wrbuf, 2, rdbuf);
219 	if (error)
220 		return error;
221 
222 	if ((wrbuf[0] ^ wrbuf[1] ^ rdbuf[0]) != rdbuf[1]) {
223 		dev_err(&tsdata->client->dev,
224 			"crc error: 0x%02x expected, got 0x%02x\n",
225 			wrbuf[0] ^ wrbuf[1] ^ rdbuf[0], rdbuf[1]);
226 		return -EIO;
227 	}
228 
229 	return rdbuf[0];
230 }
231 
232 struct edt_ft5x06_attribute {
233 	struct device_attribute dattr;
234 	size_t field_offset;
235 	u8 limit_low;
236 	u8 limit_high;
237 	u8 addr;
238 };
239 
240 #define EDT_ATTR(_field, _mode, _addr, _limit_low, _limit_high)		\
241 	struct edt_ft5x06_attribute edt_ft5x06_attr_##_field = {	\
242 		.dattr = __ATTR(_field, _mode,				\
243 				edt_ft5x06_setting_show,		\
244 				edt_ft5x06_setting_store),		\
245 		.field_offset =						\
246 			offsetof(struct edt_ft5x06_ts_data, _field),	\
247 		.limit_low = _limit_low,				\
248 		.limit_high = _limit_high,				\
249 		.addr = _addr,						\
250 	}
251 
252 static ssize_t edt_ft5x06_setting_show(struct device *dev,
253 				       struct device_attribute *dattr,
254 				       char *buf)
255 {
256 	struct i2c_client *client = to_i2c_client(dev);
257 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
258 	struct edt_ft5x06_attribute *attr =
259 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
260 	u8 *field = (u8 *)((char *)tsdata + attr->field_offset);
261 	int val;
262 	size_t count = 0;
263 	int error = 0;
264 
265 	mutex_lock(&tsdata->mutex);
266 
267 	if (tsdata->factory_mode) {
268 		error = -EIO;
269 		goto out;
270 	}
271 
272 	val = edt_ft5x06_register_read(tsdata, attr->addr);
273 	if (val < 0) {
274 		error = val;
275 		dev_err(&tsdata->client->dev,
276 			"Failed to fetch attribute %s, error %d\n",
277 			dattr->attr.name, error);
278 		goto out;
279 	}
280 
281 	if (val != *field) {
282 		dev_warn(&tsdata->client->dev,
283 			 "%s: read (%d) and stored value (%d) differ\n",
284 			 dattr->attr.name, val, *field);
285 		*field = val;
286 	}
287 
288 	count = scnprintf(buf, PAGE_SIZE, "%d\n", val);
289 out:
290 	mutex_unlock(&tsdata->mutex);
291 	return error ?: count;
292 }
293 
294 static ssize_t edt_ft5x06_setting_store(struct device *dev,
295 					struct device_attribute *dattr,
296 					const char *buf, size_t count)
297 {
298 	struct i2c_client *client = to_i2c_client(dev);
299 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
300 	struct edt_ft5x06_attribute *attr =
301 			container_of(dattr, struct edt_ft5x06_attribute, dattr);
302 	u8 *field = (u8 *)((char *)tsdata + attr->field_offset);
303 	unsigned int val;
304 	int error;
305 
306 	mutex_lock(&tsdata->mutex);
307 
308 	if (tsdata->factory_mode) {
309 		error = -EIO;
310 		goto out;
311 	}
312 
313 	error = kstrtouint(buf, 0, &val);
314 	if (error)
315 		goto out;
316 
317 	if (val < attr->limit_low || val > attr->limit_high) {
318 		error = -ERANGE;
319 		goto out;
320 	}
321 
322 	error = edt_ft5x06_register_write(tsdata, attr->addr, val);
323 	if (error) {
324 		dev_err(&tsdata->client->dev,
325 			"Failed to update attribute %s, error: %d\n",
326 			dattr->attr.name, error);
327 		goto out;
328 	}
329 
330 	*field = val;
331 
332 out:
333 	mutex_unlock(&tsdata->mutex);
334 	return error ?: count;
335 }
336 
337 static EDT_ATTR(gain, S_IWUSR | S_IRUGO, WORK_REGISTER_GAIN, 0, 31);
338 static EDT_ATTR(offset, S_IWUSR | S_IRUGO, WORK_REGISTER_OFFSET, 0, 31);
339 static EDT_ATTR(threshold, S_IWUSR | S_IRUGO,
340 		WORK_REGISTER_THRESHOLD, 20, 80);
341 static EDT_ATTR(report_rate, S_IWUSR | S_IRUGO,
342 		WORK_REGISTER_REPORT_RATE, 3, 14);
343 
344 static struct attribute *edt_ft5x06_attrs[] = {
345 	&edt_ft5x06_attr_gain.dattr.attr,
346 	&edt_ft5x06_attr_offset.dattr.attr,
347 	&edt_ft5x06_attr_threshold.dattr.attr,
348 	&edt_ft5x06_attr_report_rate.dattr.attr,
349 	NULL
350 };
351 
352 static const struct attribute_group edt_ft5x06_attr_group = {
353 	.attrs = edt_ft5x06_attrs,
354 };
355 
356 #ifdef CONFIG_DEBUG_FS
357 static int edt_ft5x06_factory_mode(struct edt_ft5x06_ts_data *tsdata)
358 {
359 	struct i2c_client *client = tsdata->client;
360 	int retries = EDT_SWITCH_MODE_RETRIES;
361 	int ret;
362 	int error;
363 
364 	disable_irq(client->irq);
365 
366 	if (!tsdata->raw_buffer) {
367 		tsdata->raw_bufsize = tsdata->num_x * tsdata->num_y *
368 				      sizeof(u16);
369 		tsdata->raw_buffer = kzalloc(tsdata->raw_bufsize, GFP_KERNEL);
370 		if (!tsdata->raw_buffer) {
371 			error = -ENOMEM;
372 			goto err_out;
373 		}
374 	}
375 
376 	/* mode register is 0x3c when in the work mode */
377 	error = edt_ft5x06_register_write(tsdata, WORK_REGISTER_OPMODE, 0x03);
378 	if (error) {
379 		dev_err(&client->dev,
380 			"failed to switch to factory mode, error %d\n", error);
381 		goto err_out;
382 	}
383 
384 	tsdata->factory_mode = true;
385 	do {
386 		mdelay(EDT_SWITCH_MODE_DELAY);
387 		/* mode register is 0x01 when in factory mode */
388 		ret = edt_ft5x06_register_read(tsdata, FACTORY_REGISTER_OPMODE);
389 		if (ret == 0x03)
390 			break;
391 	} while (--retries > 0);
392 
393 	if (retries == 0) {
394 		dev_err(&client->dev, "not in factory mode after %dms.\n",
395 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
396 		error = -EIO;
397 		goto err_out;
398 	}
399 
400 	return 0;
401 
402 err_out:
403 	kfree(tsdata->raw_buffer);
404 	tsdata->raw_buffer = NULL;
405 	tsdata->factory_mode = false;
406 	enable_irq(client->irq);
407 
408 	return error;
409 }
410 
411 static int edt_ft5x06_work_mode(struct edt_ft5x06_ts_data *tsdata)
412 {
413 	struct i2c_client *client = tsdata->client;
414 	int retries = EDT_SWITCH_MODE_RETRIES;
415 	int ret;
416 	int error;
417 
418 	/* mode register is 0x01 when in the factory mode */
419 	error = edt_ft5x06_register_write(tsdata, FACTORY_REGISTER_OPMODE, 0x1);
420 	if (error) {
421 		dev_err(&client->dev,
422 			"failed to switch to work mode, error: %d\n", error);
423 		return error;
424 	}
425 
426 	tsdata->factory_mode = false;
427 
428 	do {
429 		mdelay(EDT_SWITCH_MODE_DELAY);
430 		/* mode register is 0x01 when in factory mode */
431 		ret = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OPMODE);
432 		if (ret == 0x01)
433 			break;
434 	} while (--retries > 0);
435 
436 	if (retries == 0) {
437 		dev_err(&client->dev, "not in work mode after %dms.\n",
438 			EDT_SWITCH_MODE_RETRIES * EDT_SWITCH_MODE_DELAY);
439 		tsdata->factory_mode = true;
440 		return -EIO;
441 	}
442 
443 	kfree(tsdata->raw_buffer);
444 	tsdata->raw_buffer = NULL;
445 
446 	/* restore parameters */
447 	edt_ft5x06_register_write(tsdata, WORK_REGISTER_THRESHOLD,
448 				  tsdata->threshold);
449 	edt_ft5x06_register_write(tsdata, WORK_REGISTER_GAIN,
450 				  tsdata->gain);
451 	edt_ft5x06_register_write(tsdata, WORK_REGISTER_OFFSET,
452 				  tsdata->offset);
453 	edt_ft5x06_register_write(tsdata, WORK_REGISTER_REPORT_RATE,
454 				  tsdata->report_rate);
455 
456 	enable_irq(client->irq);
457 
458 	return 0;
459 }
460 
461 static int edt_ft5x06_debugfs_mode_get(void *data, u64 *mode)
462 {
463 	struct edt_ft5x06_ts_data *tsdata = data;
464 
465 	*mode = tsdata->factory_mode;
466 
467 	return 0;
468 };
469 
470 static int edt_ft5x06_debugfs_mode_set(void *data, u64 mode)
471 {
472 	struct edt_ft5x06_ts_data *tsdata = data;
473 	int retval = 0;
474 
475 	if (mode > 1)
476 		return -ERANGE;
477 
478 	mutex_lock(&tsdata->mutex);
479 
480 	if (mode != tsdata->factory_mode) {
481 		retval = mode ? edt_ft5x06_factory_mode(tsdata) :
482 			        edt_ft5x06_work_mode(tsdata);
483 	}
484 
485 	mutex_unlock(&tsdata->mutex);
486 
487 	return retval;
488 };
489 
490 DEFINE_SIMPLE_ATTRIBUTE(debugfs_mode_fops, edt_ft5x06_debugfs_mode_get,
491 			edt_ft5x06_debugfs_mode_set, "%llu\n");
492 
493 static ssize_t edt_ft5x06_debugfs_raw_data_read(struct file *file,
494 				char __user *buf, size_t count, loff_t *off)
495 {
496 	struct edt_ft5x06_ts_data *tsdata = file->private_data;
497 	struct i2c_client *client = tsdata->client;
498 	int retries  = EDT_RAW_DATA_RETRIES;
499 	int val, i, error;
500 	size_t read = 0;
501 	int colbytes;
502 	char wrbuf[3];
503 	u8 *rdbuf;
504 
505 	if (*off < 0 || *off >= tsdata->raw_bufsize)
506 		return 0;
507 
508 	mutex_lock(&tsdata->mutex);
509 
510 	if (!tsdata->factory_mode || !tsdata->raw_buffer) {
511 		error = -EIO;
512 		goto out;
513 	}
514 
515 	error = edt_ft5x06_register_write(tsdata, 0x08, 0x01);
516 	if (error) {
517 		dev_dbg(&client->dev,
518 			"failed to write 0x08 register, error %d\n", error);
519 		goto out;
520 	}
521 
522 	do {
523 		msleep(EDT_RAW_DATA_DELAY);
524 		val = edt_ft5x06_register_read(tsdata, 0x08);
525 		if (val < 1)
526 			break;
527 	} while (--retries > 0);
528 
529 	if (val < 0) {
530 		error = val;
531 		dev_dbg(&client->dev,
532 			"failed to read 0x08 register, error %d\n", error);
533 		goto out;
534 	}
535 
536 	if (retries == 0) {
537 		dev_dbg(&client->dev,
538 			"timed out waiting for register to settle\n");
539 		error = -ETIMEDOUT;
540 		goto out;
541 	}
542 
543 	rdbuf = tsdata->raw_buffer;
544 	colbytes = tsdata->num_y * sizeof(u16);
545 
546 	wrbuf[0] = 0xf5;
547 	wrbuf[1] = 0x0e;
548 	for (i = 0; i < tsdata->num_x; i++) {
549 		wrbuf[2] = i;  /* column index */
550 		error = edt_ft5x06_ts_readwrite(tsdata->client,
551 						sizeof(wrbuf), wrbuf,
552 						colbytes, rdbuf);
553 		if (error)
554 			goto out;
555 
556 		rdbuf += colbytes;
557 	}
558 
559 	read = min_t(size_t, count, tsdata->raw_bufsize - *off);
560 	if (copy_to_user(buf, tsdata->raw_buffer + *off, read)) {
561 		error = -EFAULT;
562 		goto out;
563 	}
564 
565 	*off += read;
566 out:
567 	mutex_unlock(&tsdata->mutex);
568 	return error ?: read;
569 };
570 
571 
572 static const struct file_operations debugfs_raw_data_fops = {
573 	.open = simple_open,
574 	.read = edt_ft5x06_debugfs_raw_data_read,
575 };
576 
577 static void
578 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
579 			      const char *debugfs_name)
580 {
581 	tsdata->debug_dir = debugfs_create_dir(debugfs_name, NULL);
582 	if (!tsdata->debug_dir)
583 		return;
584 
585 	debugfs_create_u16("num_x", S_IRUSR, tsdata->debug_dir, &tsdata->num_x);
586 	debugfs_create_u16("num_y", S_IRUSR, tsdata->debug_dir, &tsdata->num_y);
587 
588 	debugfs_create_file("mode", S_IRUSR | S_IWUSR,
589 			    tsdata->debug_dir, tsdata, &debugfs_mode_fops);
590 	debugfs_create_file("raw_data", S_IRUSR,
591 			    tsdata->debug_dir, tsdata, &debugfs_raw_data_fops);
592 }
593 
594 static void
595 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
596 {
597 	if (tsdata->debug_dir)
598 		debugfs_remove_recursive(tsdata->debug_dir);
599 	kfree(tsdata->raw_buffer);
600 }
601 
602 #else
603 
604 static inline void
605 edt_ft5x06_ts_prepare_debugfs(struct edt_ft5x06_ts_data *tsdata,
606 			      const char *debugfs_name)
607 {
608 }
609 
610 static inline void
611 edt_ft5x06_ts_teardown_debugfs(struct edt_ft5x06_ts_data *tsdata)
612 {
613 }
614 
615 #endif /* CONFIG_DEBUGFS */
616 
617 
618 
619 static int edt_ft5x06_ts_reset(struct i2c_client *client,
620 					 int reset_pin)
621 {
622 	int error;
623 
624 	if (gpio_is_valid(reset_pin)) {
625 		/* this pulls reset down, enabling the low active reset */
626 		error = gpio_request_one(reset_pin, GPIOF_OUT_INIT_LOW,
627 					 "edt-ft5x06 reset");
628 		if (error) {
629 			dev_err(&client->dev,
630 				"Failed to request GPIO %d as reset pin, error %d\n",
631 				reset_pin, error);
632 			return error;
633 		}
634 
635 		mdelay(50);
636 		gpio_set_value(reset_pin, 1);
637 		mdelay(100);
638 	}
639 
640 	return 0;
641 }
642 
643 static int edt_ft5x06_ts_identify(struct i2c_client *client,
644 					    char *model_name,
645 					    char *fw_version)
646 {
647 	u8 rdbuf[EDT_NAME_LEN];
648 	char *p;
649 	int error;
650 
651 	error = edt_ft5x06_ts_readwrite(client, 1, "\xbb",
652 					EDT_NAME_LEN - 1, rdbuf);
653 	if (error)
654 		return error;
655 
656 	/* remove last '$' end marker */
657 	rdbuf[EDT_NAME_LEN - 1] = '\0';
658 	if (rdbuf[EDT_NAME_LEN - 2] == '$')
659 		rdbuf[EDT_NAME_LEN - 2] = '\0';
660 
661 	/* look for Model/Version separator */
662 	p = strchr(rdbuf, '*');
663 	if (p)
664 		*p++ = '\0';
665 
666 	strlcpy(model_name, rdbuf + 1, EDT_NAME_LEN);
667 	strlcpy(fw_version, p ? p : "", EDT_NAME_LEN);
668 
669 	return 0;
670 }
671 
672 #define EDT_ATTR_CHECKSET(name, reg) \
673 	if (pdata->name >= edt_ft5x06_attr_##name.limit_low &&		\
674 	    pdata->name <= edt_ft5x06_attr_##name.limit_high)		\
675 		edt_ft5x06_register_write(tsdata, reg, pdata->name)
676 
677 static void
678 edt_ft5x06_ts_get_defaults(struct edt_ft5x06_ts_data *tsdata,
679 			   const struct edt_ft5x06_platform_data *pdata)
680 {
681 	if (!pdata->use_parameters)
682 		return;
683 
684 	/* pick up defaults from the platform data */
685 	EDT_ATTR_CHECKSET(threshold, WORK_REGISTER_THRESHOLD);
686 	EDT_ATTR_CHECKSET(gain, WORK_REGISTER_GAIN);
687 	EDT_ATTR_CHECKSET(offset, WORK_REGISTER_OFFSET);
688 	EDT_ATTR_CHECKSET(report_rate, WORK_REGISTER_REPORT_RATE);
689 }
690 
691 static void
692 edt_ft5x06_ts_get_parameters(struct edt_ft5x06_ts_data *tsdata)
693 {
694 	tsdata->threshold = edt_ft5x06_register_read(tsdata,
695 						     WORK_REGISTER_THRESHOLD);
696 	tsdata->gain = edt_ft5x06_register_read(tsdata, WORK_REGISTER_GAIN);
697 	tsdata->offset = edt_ft5x06_register_read(tsdata, WORK_REGISTER_OFFSET);
698 	tsdata->report_rate = edt_ft5x06_register_read(tsdata,
699 						WORK_REGISTER_REPORT_RATE);
700 	tsdata->num_x = edt_ft5x06_register_read(tsdata, WORK_REGISTER_NUM_X);
701 	tsdata->num_y = edt_ft5x06_register_read(tsdata, WORK_REGISTER_NUM_Y);
702 }
703 
704 static int edt_ft5x06_ts_probe(struct i2c_client *client,
705 					 const struct i2c_device_id *id)
706 {
707 	const struct edt_ft5x06_platform_data *pdata =
708 						client->dev.platform_data;
709 	struct edt_ft5x06_ts_data *tsdata;
710 	struct input_dev *input;
711 	int error;
712 	char fw_version[EDT_NAME_LEN];
713 
714 	dev_dbg(&client->dev, "probing for EDT FT5x06 I2C\n");
715 
716 	if (!pdata) {
717 		dev_err(&client->dev, "no platform data?\n");
718 		return -EINVAL;
719 	}
720 
721 	error = edt_ft5x06_ts_reset(client, pdata->reset_pin);
722 	if (error)
723 		return error;
724 
725 	if (gpio_is_valid(pdata->irq_pin)) {
726 		error = gpio_request_one(pdata->irq_pin,
727 					 GPIOF_IN, "edt-ft5x06 irq");
728 		if (error) {
729 			dev_err(&client->dev,
730 				"Failed to request GPIO %d, error %d\n",
731 				pdata->irq_pin, error);
732 			return error;
733 		}
734 	}
735 
736 	tsdata = kzalloc(sizeof(*tsdata), GFP_KERNEL);
737 	input = input_allocate_device();
738 	if (!tsdata || !input) {
739 		dev_err(&client->dev, "failed to allocate driver data.\n");
740 		error = -ENOMEM;
741 		goto err_free_mem;
742 	}
743 
744 	mutex_init(&tsdata->mutex);
745 	tsdata->client = client;
746 	tsdata->input = input;
747 	tsdata->factory_mode = false;
748 
749 	error = edt_ft5x06_ts_identify(client, tsdata->name, fw_version);
750 	if (error) {
751 		dev_err(&client->dev, "touchscreen probe failed\n");
752 		goto err_free_mem;
753 	}
754 
755 	edt_ft5x06_ts_get_defaults(tsdata, pdata);
756 	edt_ft5x06_ts_get_parameters(tsdata);
757 
758 	dev_dbg(&client->dev,
759 		"Model \"%s\", Rev. \"%s\", %dx%d sensors\n",
760 		tsdata->name, fw_version, tsdata->num_x, tsdata->num_y);
761 
762 	input->name = tsdata->name;
763 	input->id.bustype = BUS_I2C;
764 	input->dev.parent = &client->dev;
765 
766 	__set_bit(EV_SYN, input->evbit);
767 	__set_bit(EV_KEY, input->evbit);
768 	__set_bit(EV_ABS, input->evbit);
769 	__set_bit(BTN_TOUCH, input->keybit);
770 	input_set_abs_params(input, ABS_X, 0, tsdata->num_x * 64 - 1, 0, 0);
771 	input_set_abs_params(input, ABS_Y, 0, tsdata->num_y * 64 - 1, 0, 0);
772 	input_set_abs_params(input, ABS_MT_POSITION_X,
773 			     0, tsdata->num_x * 64 - 1, 0, 0);
774 	input_set_abs_params(input, ABS_MT_POSITION_Y,
775 			     0, tsdata->num_y * 64 - 1, 0, 0);
776 	error = input_mt_init_slots(input, MAX_SUPPORT_POINTS, 0);
777 	if (error) {
778 		dev_err(&client->dev, "Unable to init MT slots.\n");
779 		goto err_free_mem;
780 	}
781 
782 	input_set_drvdata(input, tsdata);
783 	i2c_set_clientdata(client, tsdata);
784 
785 	error = request_threaded_irq(client->irq, NULL, edt_ft5x06_ts_isr,
786 				     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
787 				     client->name, tsdata);
788 	if (error) {
789 		dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
790 		goto err_free_mem;
791 	}
792 
793 	error = sysfs_create_group(&client->dev.kobj, &edt_ft5x06_attr_group);
794 	if (error)
795 		goto err_free_irq;
796 
797 	error = input_register_device(input);
798 	if (error)
799 		goto err_remove_attrs;
800 
801 	edt_ft5x06_ts_prepare_debugfs(tsdata, dev_driver_string(&client->dev));
802 	device_init_wakeup(&client->dev, 1);
803 
804 	dev_dbg(&client->dev,
805 		"EDT FT5x06 initialized: IRQ pin %d, Reset pin %d.\n",
806 		pdata->irq_pin, pdata->reset_pin);
807 
808 	return 0;
809 
810 err_remove_attrs:
811 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
812 err_free_irq:
813 	free_irq(client->irq, tsdata);
814 err_free_mem:
815 	input_free_device(input);
816 	kfree(tsdata);
817 
818 	if (gpio_is_valid(pdata->irq_pin))
819 		gpio_free(pdata->irq_pin);
820 
821 	return error;
822 }
823 
824 static int edt_ft5x06_ts_remove(struct i2c_client *client)
825 {
826 	const struct edt_ft5x06_platform_data *pdata =
827 						dev_get_platdata(&client->dev);
828 	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
829 
830 	edt_ft5x06_ts_teardown_debugfs(tsdata);
831 	sysfs_remove_group(&client->dev.kobj, &edt_ft5x06_attr_group);
832 
833 	free_irq(client->irq, tsdata);
834 	input_unregister_device(tsdata->input);
835 
836 	if (gpio_is_valid(pdata->irq_pin))
837 		gpio_free(pdata->irq_pin);
838 	if (gpio_is_valid(pdata->reset_pin))
839 		gpio_free(pdata->reset_pin);
840 
841 	kfree(tsdata);
842 
843 	return 0;
844 }
845 
846 #ifdef CONFIG_PM_SLEEP
847 static int edt_ft5x06_ts_suspend(struct device *dev)
848 {
849 	struct i2c_client *client = to_i2c_client(dev);
850 
851 	if (device_may_wakeup(dev))
852 		enable_irq_wake(client->irq);
853 
854 	return 0;
855 }
856 
857 static int edt_ft5x06_ts_resume(struct device *dev)
858 {
859 	struct i2c_client *client = to_i2c_client(dev);
860 
861 	if (device_may_wakeup(dev))
862 		disable_irq_wake(client->irq);
863 
864 	return 0;
865 }
866 #endif
867 
868 static SIMPLE_DEV_PM_OPS(edt_ft5x06_ts_pm_ops,
869 			 edt_ft5x06_ts_suspend, edt_ft5x06_ts_resume);
870 
871 static const struct i2c_device_id edt_ft5x06_ts_id[] = {
872 	{ "edt-ft5x06", 0 },
873 	{ }
874 };
875 MODULE_DEVICE_TABLE(i2c, edt_ft5x06_ts_id);
876 
877 static struct i2c_driver edt_ft5x06_ts_driver = {
878 	.driver = {
879 		.owner = THIS_MODULE,
880 		.name = "edt_ft5x06",
881 		.pm = &edt_ft5x06_ts_pm_ops,
882 	},
883 	.id_table = edt_ft5x06_ts_id,
884 	.probe    = edt_ft5x06_ts_probe,
885 	.remove   = edt_ft5x06_ts_remove,
886 };
887 
888 module_i2c_driver(edt_ft5x06_ts_driver);
889 
890 MODULE_AUTHOR("Simon Budig <simon.budig@kernelconcepts.de>");
891 MODULE_DESCRIPTION("EDT FT5x06 I2C Touchscreen Driver");
892 MODULE_LICENSE("GPL");
893