1 /*
2  * Elan I2C/SMBus Touchpad driver
3  *
4  * Copyright (c) 2013 ELAN Microelectronics Corp.
5  *
6  * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
7  * Author: KT Liao <kt.liao@emc.com.tw>
8  * Version: 1.6.3
9  *
10  * Based on cyapa driver:
11  * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
12  * copyright (c) 2011-2012 Google, Inc.
13  *
14  * This program is free software; you can redistribute it and/or modify it
15  * under the terms of the GNU General Public License version 2 as published
16  * by the Free Software Foundation.
17  *
18  * Trademarks are the property of their respective owners.
19  */
20 
21 #include <linux/acpi.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/firmware.h>
25 #include <linux/i2c.h>
26 #include <linux/init.h>
27 #include <linux/input/mt.h>
28 #include <linux/interrupt.h>
29 #include <linux/irq.h>
30 #include <linux/module.h>
31 #include <linux/slab.h>
32 #include <linux/kernel.h>
33 #include <linux/sched.h>
34 #include <linux/input.h>
35 #include <linux/uaccess.h>
36 #include <linux/jiffies.h>
37 #include <linux/completion.h>
38 #include <linux/of.h>
39 #include <linux/regulator/consumer.h>
40 #include <asm/unaligned.h>
41 
42 #include "elan_i2c.h"
43 
44 #define DRIVER_NAME		"elan_i2c"
45 #define ELAN_VENDOR_ID		0x04f3
46 #define ETP_MAX_PRESSURE	255
47 #define ETP_FWIDTH_REDUCE	90
48 #define ETP_FINGER_WIDTH	15
49 #define ETP_RETRY_COUNT		3
50 
51 #define ETP_MAX_FINGERS		5
52 #define ETP_FINGER_DATA_LEN	5
53 #define ETP_REPORT_ID		0x5D
54 #define ETP_REPORT_ID_OFFSET	2
55 #define ETP_TOUCH_INFO_OFFSET	3
56 #define ETP_FINGER_DATA_OFFSET	4
57 #define ETP_HOVER_INFO_OFFSET	30
58 #define ETP_MAX_REPORT_LEN	34
59 
60 /* The main device structure */
61 struct elan_tp_data {
62 	struct i2c_client	*client;
63 	struct input_dev	*input;
64 	struct regulator	*vcc;
65 
66 	const struct elan_transport_ops *ops;
67 
68 	/* for fw update */
69 	struct completion	fw_completion;
70 	bool			in_fw_update;
71 
72 	struct mutex		sysfs_mutex;
73 
74 	unsigned int		max_x;
75 	unsigned int		max_y;
76 	unsigned int		width_x;
77 	unsigned int		width_y;
78 	unsigned int		x_res;
79 	unsigned int		y_res;
80 
81 	u8			pattern;
82 	u16			product_id;
83 	u8			fw_version;
84 	u8			sm_version;
85 	u8			iap_version;
86 	u16			fw_checksum;
87 	int			pressure_adjustment;
88 	u8			mode;
89 	u16			ic_type;
90 	u16			fw_validpage_count;
91 	u16			fw_signature_address;
92 
93 	bool			irq_wake;
94 
95 	u8			min_baseline;
96 	u8			max_baseline;
97 	bool			baseline_ready;
98 	u8			clickpad;
99 };
100 
101 static int elan_get_fwinfo(u16 ic_type, u16 *validpage_count,
102 			   u16 *signature_address)
103 {
104 	switch (ic_type) {
105 	case 0x00:
106 	case 0x06:
107 	case 0x08:
108 		*validpage_count = 512;
109 		break;
110 	case 0x03:
111 	case 0x07:
112 	case 0x09:
113 	case 0x0A:
114 	case 0x0B:
115 	case 0x0C:
116 		*validpage_count = 768;
117 		break;
118 	case 0x0D:
119 		*validpage_count = 896;
120 		break;
121 	case 0x0E:
122 		*validpage_count = 640;
123 		break;
124 	case 0x10:
125 		*validpage_count = 1024;
126 		break;
127 	default:
128 		/* unknown ic type clear value */
129 		*validpage_count = 0;
130 		*signature_address = 0;
131 		return -ENXIO;
132 	}
133 
134 	*signature_address =
135 		(*validpage_count * ETP_FW_PAGE_SIZE) - ETP_FW_SIGNATURE_SIZE;
136 
137 	return 0;
138 }
139 
140 static int elan_enable_power(struct elan_tp_data *data)
141 {
142 	int repeat = ETP_RETRY_COUNT;
143 	int error;
144 
145 	error = regulator_enable(data->vcc);
146 	if (error) {
147 		dev_err(&data->client->dev,
148 			"failed to enable regulator: %d\n", error);
149 		return error;
150 	}
151 
152 	do {
153 		error = data->ops->power_control(data->client, true);
154 		if (error >= 0)
155 			return 0;
156 
157 		msleep(30);
158 	} while (--repeat > 0);
159 
160 	dev_err(&data->client->dev, "failed to enable power: %d\n", error);
161 	return error;
162 }
163 
164 static int elan_disable_power(struct elan_tp_data *data)
165 {
166 	int repeat = ETP_RETRY_COUNT;
167 	int error;
168 
169 	do {
170 		error = data->ops->power_control(data->client, false);
171 		if (!error) {
172 			error = regulator_disable(data->vcc);
173 			if (error) {
174 				dev_err(&data->client->dev,
175 					"failed to disable regulator: %d\n",
176 					error);
177 				/* Attempt to power the chip back up */
178 				data->ops->power_control(data->client, true);
179 				break;
180 			}
181 
182 			return 0;
183 		}
184 
185 		msleep(30);
186 	} while (--repeat > 0);
187 
188 	dev_err(&data->client->dev, "failed to disable power: %d\n", error);
189 	return error;
190 }
191 
192 static int elan_sleep(struct elan_tp_data *data)
193 {
194 	int repeat = ETP_RETRY_COUNT;
195 	int error;
196 
197 	do {
198 		error = data->ops->sleep_control(data->client, true);
199 		if (!error)
200 			return 0;
201 
202 		msleep(30);
203 	} while (--repeat > 0);
204 
205 	return error;
206 }
207 
208 static int elan_query_product(struct elan_tp_data *data)
209 {
210 	int error;
211 
212 	error = data->ops->get_product_id(data->client, &data->product_id);
213 	if (error)
214 		return error;
215 
216 	error = data->ops->get_sm_version(data->client, &data->ic_type,
217 					  &data->sm_version, &data->clickpad);
218 	if (error)
219 		return error;
220 
221 	return 0;
222 }
223 
224 static int elan_check_ASUS_special_fw(struct elan_tp_data *data)
225 {
226 	if (data->ic_type == 0x0E) {
227 		switch (data->product_id) {
228 		case 0x05 ... 0x07:
229 		case 0x09:
230 		case 0x13:
231 			return true;
232 		}
233 	} else if (data->ic_type == 0x08 && data->product_id == 0x26) {
234 		/* ASUS EeeBook X205TA */
235 		return true;
236 	}
237 
238 	return false;
239 }
240 
241 static int __elan_initialize(struct elan_tp_data *data)
242 {
243 	struct i2c_client *client = data->client;
244 	bool woken_up = false;
245 	int error;
246 
247 	error = data->ops->initialize(client);
248 	if (error) {
249 		dev_err(&client->dev, "device initialize failed: %d\n", error);
250 		return error;
251 	}
252 
253 	error = elan_query_product(data);
254 	if (error)
255 		return error;
256 
257 	/*
258 	 * Some ASUS devices were shipped with firmware that requires
259 	 * touchpads to be woken up first, before attempting to switch
260 	 * them into absolute reporting mode.
261 	 */
262 	if (elan_check_ASUS_special_fw(data)) {
263 		error = data->ops->sleep_control(client, false);
264 		if (error) {
265 			dev_err(&client->dev,
266 				"failed to wake device up: %d\n", error);
267 			return error;
268 		}
269 
270 		msleep(200);
271 		woken_up = true;
272 	}
273 
274 	data->mode |= ETP_ENABLE_ABS;
275 	error = data->ops->set_mode(client, data->mode);
276 	if (error) {
277 		dev_err(&client->dev,
278 			"failed to switch to absolute mode: %d\n", error);
279 		return error;
280 	}
281 
282 	if (!woken_up) {
283 		error = data->ops->sleep_control(client, false);
284 		if (error) {
285 			dev_err(&client->dev,
286 				"failed to wake device up: %d\n", error);
287 			return error;
288 		}
289 	}
290 
291 	return 0;
292 }
293 
294 static int elan_initialize(struct elan_tp_data *data)
295 {
296 	int repeat = ETP_RETRY_COUNT;
297 	int error;
298 
299 	do {
300 		error = __elan_initialize(data);
301 		if (!error)
302 			return 0;
303 
304 		msleep(30);
305 	} while (--repeat > 0);
306 
307 	return error;
308 }
309 
310 static int elan_query_device_info(struct elan_tp_data *data)
311 {
312 	int error;
313 	u16 ic_type;
314 
315 	error = data->ops->get_version(data->client, false, &data->fw_version);
316 	if (error)
317 		return error;
318 
319 	error = data->ops->get_checksum(data->client, false,
320 					&data->fw_checksum);
321 	if (error)
322 		return error;
323 
324 	error = data->ops->get_version(data->client, true, &data->iap_version);
325 	if (error)
326 		return error;
327 
328 	error = data->ops->get_pressure_adjustment(data->client,
329 						   &data->pressure_adjustment);
330 	if (error)
331 		return error;
332 
333 	error = data->ops->get_pattern(data->client, &data->pattern);
334 	if (error)
335 		return error;
336 
337 	if (data->pattern == 0x01)
338 		ic_type = data->ic_type;
339 	else
340 		ic_type = data->iap_version;
341 
342 	error = elan_get_fwinfo(ic_type, &data->fw_validpage_count,
343 				&data->fw_signature_address);
344 	if (error)
345 		dev_warn(&data->client->dev,
346 			 "unexpected iap version %#04x (ic type: %#04x), firmware update will not work\n",
347 			 data->iap_version, data->ic_type);
348 
349 	return 0;
350 }
351 
352 static unsigned int elan_convert_resolution(u8 val)
353 {
354 	/*
355 	 * (value from firmware) * 10 + 790 = dpi
356 	 *
357 	 * We also have to convert dpi to dots/mm (*10/254 to avoid floating
358 	 * point).
359 	 */
360 
361 	return ((int)(char)val * 10 + 790) * 10 / 254;
362 }
363 
364 static int elan_query_device_parameters(struct elan_tp_data *data)
365 {
366 	unsigned int x_traces, y_traces;
367 	u8 hw_x_res, hw_y_res;
368 	int error;
369 
370 	error = data->ops->get_max(data->client, &data->max_x, &data->max_y);
371 	if (error)
372 		return error;
373 
374 	error = data->ops->get_num_traces(data->client, &x_traces, &y_traces);
375 	if (error)
376 		return error;
377 
378 	data->width_x = data->max_x / x_traces;
379 	data->width_y = data->max_y / y_traces;
380 
381 	error = data->ops->get_resolution(data->client, &hw_x_res, &hw_y_res);
382 	if (error)
383 		return error;
384 
385 	data->x_res = elan_convert_resolution(hw_x_res);
386 	data->y_res = elan_convert_resolution(hw_y_res);
387 
388 	return 0;
389 }
390 
391 /*
392  **********************************************************
393  * IAP firmware updater related routines
394  **********************************************************
395  */
396 static int elan_write_fw_block(struct elan_tp_data *data,
397 			       const u8 *page, u16 checksum, int idx)
398 {
399 	int retry = ETP_RETRY_COUNT;
400 	int error;
401 
402 	do {
403 		error = data->ops->write_fw_block(data->client,
404 						  page, checksum, idx);
405 		if (!error)
406 			return 0;
407 
408 		dev_dbg(&data->client->dev,
409 			"IAP retrying page %d (error: %d)\n", idx, error);
410 	} while (--retry > 0);
411 
412 	return error;
413 }
414 
415 static int __elan_update_firmware(struct elan_tp_data *data,
416 				  const struct firmware *fw)
417 {
418 	struct i2c_client *client = data->client;
419 	struct device *dev = &client->dev;
420 	int i, j;
421 	int error;
422 	u16 iap_start_addr;
423 	u16 boot_page_count;
424 	u16 sw_checksum = 0, fw_checksum = 0;
425 
426 	error = data->ops->prepare_fw_update(client);
427 	if (error)
428 		return error;
429 
430 	iap_start_addr = get_unaligned_le16(&fw->data[ETP_IAP_START_ADDR * 2]);
431 
432 	boot_page_count = (iap_start_addr * 2) / ETP_FW_PAGE_SIZE;
433 	for (i = boot_page_count; i < data->fw_validpage_count; i++) {
434 		u16 checksum = 0;
435 		const u8 *page = &fw->data[i * ETP_FW_PAGE_SIZE];
436 
437 		for (j = 0; j < ETP_FW_PAGE_SIZE; j += 2)
438 			checksum += ((page[j + 1] << 8) | page[j]);
439 
440 		error = elan_write_fw_block(data, page, checksum, i);
441 		if (error) {
442 			dev_err(dev, "write page %d fail: %d\n", i, error);
443 			return error;
444 		}
445 
446 		sw_checksum += checksum;
447 	}
448 
449 	/* Wait WDT reset and power on reset */
450 	msleep(600);
451 
452 	error = data->ops->finish_fw_update(client, &data->fw_completion);
453 	if (error)
454 		return error;
455 
456 	error = data->ops->get_checksum(client, true, &fw_checksum);
457 	if (error)
458 		return error;
459 
460 	if (sw_checksum != fw_checksum) {
461 		dev_err(dev, "checksum diff sw=[%04X], fw=[%04X]\n",
462 			sw_checksum, fw_checksum);
463 		return -EIO;
464 	}
465 
466 	return 0;
467 }
468 
469 static int elan_update_firmware(struct elan_tp_data *data,
470 				const struct firmware *fw)
471 {
472 	struct i2c_client *client = data->client;
473 	int retval;
474 
475 	dev_dbg(&client->dev, "Starting firmware update....\n");
476 
477 	disable_irq(client->irq);
478 	data->in_fw_update = true;
479 
480 	retval = __elan_update_firmware(data, fw);
481 	if (retval) {
482 		dev_err(&client->dev, "firmware update failed: %d\n", retval);
483 		data->ops->iap_reset(client);
484 	} else {
485 		/* Reinitialize TP after fw is updated */
486 		elan_initialize(data);
487 		elan_query_device_info(data);
488 	}
489 
490 	data->in_fw_update = false;
491 	enable_irq(client->irq);
492 
493 	return retval;
494 }
495 
496 /*
497  *******************************************************************
498  * SYSFS attributes
499  *******************************************************************
500  */
501 static ssize_t elan_sysfs_read_fw_checksum(struct device *dev,
502 					   struct device_attribute *attr,
503 					   char *buf)
504 {
505 	struct i2c_client *client = to_i2c_client(dev);
506 	struct elan_tp_data *data = i2c_get_clientdata(client);
507 
508 	return sprintf(buf, "0x%04x\n", data->fw_checksum);
509 }
510 
511 static ssize_t elan_sysfs_read_product_id(struct device *dev,
512 					 struct device_attribute *attr,
513 					 char *buf)
514 {
515 	struct i2c_client *client = to_i2c_client(dev);
516 	struct elan_tp_data *data = i2c_get_clientdata(client);
517 
518 	return sprintf(buf, ETP_PRODUCT_ID_FORMAT_STRING "\n",
519 		       data->product_id);
520 }
521 
522 static ssize_t elan_sysfs_read_fw_ver(struct device *dev,
523 				      struct device_attribute *attr,
524 				      char *buf)
525 {
526 	struct i2c_client *client = to_i2c_client(dev);
527 	struct elan_tp_data *data = i2c_get_clientdata(client);
528 
529 	return sprintf(buf, "%d.0\n", data->fw_version);
530 }
531 
532 static ssize_t elan_sysfs_read_sm_ver(struct device *dev,
533 				      struct device_attribute *attr,
534 				      char *buf)
535 {
536 	struct i2c_client *client = to_i2c_client(dev);
537 	struct elan_tp_data *data = i2c_get_clientdata(client);
538 
539 	return sprintf(buf, "%d.0\n", data->sm_version);
540 }
541 
542 static ssize_t elan_sysfs_read_iap_ver(struct device *dev,
543 				       struct device_attribute *attr,
544 				       char *buf)
545 {
546 	struct i2c_client *client = to_i2c_client(dev);
547 	struct elan_tp_data *data = i2c_get_clientdata(client);
548 
549 	return sprintf(buf, "%d.0\n", data->iap_version);
550 }
551 
552 static ssize_t elan_sysfs_update_fw(struct device *dev,
553 				    struct device_attribute *attr,
554 				    const char *buf, size_t count)
555 {
556 	struct elan_tp_data *data = dev_get_drvdata(dev);
557 	const struct firmware *fw;
558 	char *fw_name;
559 	int error;
560 	const u8 *fw_signature;
561 	static const u8 signature[] = {0xAA, 0x55, 0xCC, 0x33, 0xFF, 0xFF};
562 
563 	if (data->fw_validpage_count == 0)
564 		return -EINVAL;
565 
566 	/* Look for a firmware with the product id appended. */
567 	fw_name = kasprintf(GFP_KERNEL, ETP_FW_NAME, data->product_id);
568 	if (!fw_name) {
569 		dev_err(dev, "failed to allocate memory for firmware name\n");
570 		return -ENOMEM;
571 	}
572 
573 	dev_info(dev, "requesting fw '%s'\n", fw_name);
574 	error = request_firmware(&fw, fw_name, dev);
575 	kfree(fw_name);
576 	if (error) {
577 		dev_err(dev, "failed to request firmware: %d\n", error);
578 		return error;
579 	}
580 
581 	/* Firmware file must match signature data */
582 	fw_signature = &fw->data[data->fw_signature_address];
583 	if (memcmp(fw_signature, signature, sizeof(signature)) != 0) {
584 		dev_err(dev, "signature mismatch (expected %*ph, got %*ph)\n",
585 			(int)sizeof(signature), signature,
586 			(int)sizeof(signature), fw_signature);
587 		error = -EBADF;
588 		goto out_release_fw;
589 	}
590 
591 	error = mutex_lock_interruptible(&data->sysfs_mutex);
592 	if (error)
593 		goto out_release_fw;
594 
595 	error = elan_update_firmware(data, fw);
596 
597 	mutex_unlock(&data->sysfs_mutex);
598 
599 out_release_fw:
600 	release_firmware(fw);
601 	return error ?: count;
602 }
603 
604 static ssize_t calibrate_store(struct device *dev,
605 			       struct device_attribute *attr,
606 			       const char *buf, size_t count)
607 {
608 	struct i2c_client *client = to_i2c_client(dev);
609 	struct elan_tp_data *data = i2c_get_clientdata(client);
610 	int tries = 20;
611 	int retval;
612 	int error;
613 	u8 val[3];
614 
615 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
616 	if (retval)
617 		return retval;
618 
619 	disable_irq(client->irq);
620 
621 	data->mode |= ETP_ENABLE_CALIBRATE;
622 	retval = data->ops->set_mode(client, data->mode);
623 	if (retval) {
624 		dev_err(dev, "failed to enable calibration mode: %d\n",
625 			retval);
626 		goto out;
627 	}
628 
629 	retval = data->ops->calibrate(client);
630 	if (retval) {
631 		dev_err(dev, "failed to start calibration: %d\n",
632 			retval);
633 		goto out_disable_calibrate;
634 	}
635 
636 	val[0] = 0xff;
637 	do {
638 		/* Wait 250ms before checking if calibration has completed. */
639 		msleep(250);
640 
641 		retval = data->ops->calibrate_result(client, val);
642 		if (retval)
643 			dev_err(dev, "failed to check calibration result: %d\n",
644 				retval);
645 		else if (val[0] == 0)
646 			break; /* calibration done */
647 
648 	} while (--tries);
649 
650 	if (tries == 0) {
651 		dev_err(dev, "failed to calibrate. Timeout.\n");
652 		retval = -ETIMEDOUT;
653 	}
654 
655 out_disable_calibrate:
656 	data->mode &= ~ETP_ENABLE_CALIBRATE;
657 	error = data->ops->set_mode(data->client, data->mode);
658 	if (error) {
659 		dev_err(dev, "failed to disable calibration mode: %d\n",
660 			error);
661 		if (!retval)
662 			retval = error;
663 	}
664 out:
665 	enable_irq(client->irq);
666 	mutex_unlock(&data->sysfs_mutex);
667 	return retval ?: count;
668 }
669 
670 static ssize_t elan_sysfs_read_mode(struct device *dev,
671 				    struct device_attribute *attr,
672 				    char *buf)
673 {
674 	struct i2c_client *client = to_i2c_client(dev);
675 	struct elan_tp_data *data = i2c_get_clientdata(client);
676 	int error;
677 	enum tp_mode mode;
678 
679 	error = mutex_lock_interruptible(&data->sysfs_mutex);
680 	if (error)
681 		return error;
682 
683 	error = data->ops->iap_get_mode(data->client, &mode);
684 
685 	mutex_unlock(&data->sysfs_mutex);
686 
687 	if (error)
688 		return error;
689 
690 	return sprintf(buf, "%d\n", (int)mode);
691 }
692 
693 static DEVICE_ATTR(product_id, S_IRUGO, elan_sysfs_read_product_id, NULL);
694 static DEVICE_ATTR(firmware_version, S_IRUGO, elan_sysfs_read_fw_ver, NULL);
695 static DEVICE_ATTR(sample_version, S_IRUGO, elan_sysfs_read_sm_ver, NULL);
696 static DEVICE_ATTR(iap_version, S_IRUGO, elan_sysfs_read_iap_ver, NULL);
697 static DEVICE_ATTR(fw_checksum, S_IRUGO, elan_sysfs_read_fw_checksum, NULL);
698 static DEVICE_ATTR(mode, S_IRUGO, elan_sysfs_read_mode, NULL);
699 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, elan_sysfs_update_fw);
700 
701 static DEVICE_ATTR_WO(calibrate);
702 
703 static struct attribute *elan_sysfs_entries[] = {
704 	&dev_attr_product_id.attr,
705 	&dev_attr_firmware_version.attr,
706 	&dev_attr_sample_version.attr,
707 	&dev_attr_iap_version.attr,
708 	&dev_attr_fw_checksum.attr,
709 	&dev_attr_calibrate.attr,
710 	&dev_attr_mode.attr,
711 	&dev_attr_update_fw.attr,
712 	NULL,
713 };
714 
715 static const struct attribute_group elan_sysfs_group = {
716 	.attrs = elan_sysfs_entries,
717 };
718 
719 static ssize_t acquire_store(struct device *dev, struct device_attribute *attr,
720 			     const char *buf, size_t count)
721 {
722 	struct i2c_client *client = to_i2c_client(dev);
723 	struct elan_tp_data *data = i2c_get_clientdata(client);
724 	int error;
725 	int retval;
726 
727 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
728 	if (retval)
729 		return retval;
730 
731 	disable_irq(client->irq);
732 
733 	data->baseline_ready = false;
734 
735 	data->mode |= ETP_ENABLE_CALIBRATE;
736 	retval = data->ops->set_mode(data->client, data->mode);
737 	if (retval) {
738 		dev_err(dev, "Failed to enable calibration mode to get baseline: %d\n",
739 			retval);
740 		goto out;
741 	}
742 
743 	msleep(250);
744 
745 	retval = data->ops->get_baseline_data(data->client, true,
746 					      &data->max_baseline);
747 	if (retval) {
748 		dev_err(dev, "Failed to read max baseline form device: %d\n",
749 			retval);
750 		goto out_disable_calibrate;
751 	}
752 
753 	retval = data->ops->get_baseline_data(data->client, false,
754 					      &data->min_baseline);
755 	if (retval) {
756 		dev_err(dev, "Failed to read min baseline form device: %d\n",
757 			retval);
758 		goto out_disable_calibrate;
759 	}
760 
761 	data->baseline_ready = true;
762 
763 out_disable_calibrate:
764 	data->mode &= ~ETP_ENABLE_CALIBRATE;
765 	error = data->ops->set_mode(data->client, data->mode);
766 	if (error) {
767 		dev_err(dev, "Failed to disable calibration mode after acquiring baseline: %d\n",
768 			error);
769 		if (!retval)
770 			retval = error;
771 	}
772 out:
773 	enable_irq(client->irq);
774 	mutex_unlock(&data->sysfs_mutex);
775 	return retval ?: count;
776 }
777 
778 static ssize_t min_show(struct device *dev,
779 			struct device_attribute *attr, char *buf)
780 {
781 	struct i2c_client *client = to_i2c_client(dev);
782 	struct elan_tp_data *data = i2c_get_clientdata(client);
783 	int retval;
784 
785 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
786 	if (retval)
787 		return retval;
788 
789 	if (!data->baseline_ready) {
790 		retval = -ENODATA;
791 		goto out;
792 	}
793 
794 	retval = snprintf(buf, PAGE_SIZE, "%d", data->min_baseline);
795 
796 out:
797 	mutex_unlock(&data->sysfs_mutex);
798 	return retval;
799 }
800 
801 static ssize_t max_show(struct device *dev,
802 			struct device_attribute *attr, char *buf)
803 {
804 	struct i2c_client *client = to_i2c_client(dev);
805 	struct elan_tp_data *data = i2c_get_clientdata(client);
806 	int retval;
807 
808 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
809 	if (retval)
810 		return retval;
811 
812 	if (!data->baseline_ready) {
813 		retval = -ENODATA;
814 		goto out;
815 	}
816 
817 	retval = snprintf(buf, PAGE_SIZE, "%d", data->max_baseline);
818 
819 out:
820 	mutex_unlock(&data->sysfs_mutex);
821 	return retval;
822 }
823 
824 
825 static DEVICE_ATTR_WO(acquire);
826 static DEVICE_ATTR_RO(min);
827 static DEVICE_ATTR_RO(max);
828 
829 static struct attribute *elan_baseline_sysfs_entries[] = {
830 	&dev_attr_acquire.attr,
831 	&dev_attr_min.attr,
832 	&dev_attr_max.attr,
833 	NULL,
834 };
835 
836 static const struct attribute_group elan_baseline_sysfs_group = {
837 	.name = "baseline",
838 	.attrs = elan_baseline_sysfs_entries,
839 };
840 
841 static const struct attribute_group *elan_sysfs_groups[] = {
842 	&elan_sysfs_group,
843 	&elan_baseline_sysfs_group,
844 	NULL
845 };
846 
847 /*
848  ******************************************************************
849  * Elan isr functions
850  ******************************************************************
851  */
852 static void elan_report_contact(struct elan_tp_data *data,
853 				int contact_num, bool contact_valid,
854 				u8 *finger_data)
855 {
856 	struct input_dev *input = data->input;
857 	unsigned int pos_x, pos_y;
858 	unsigned int pressure, mk_x, mk_y;
859 	unsigned int area_x, area_y, major, minor;
860 	unsigned int scaled_pressure;
861 
862 	if (contact_valid) {
863 		pos_x = ((finger_data[0] & 0xf0) << 4) |
864 						finger_data[1];
865 		pos_y = ((finger_data[0] & 0x0f) << 8) |
866 						finger_data[2];
867 		mk_x = (finger_data[3] & 0x0f);
868 		mk_y = (finger_data[3] >> 4);
869 		pressure = finger_data[4];
870 
871 		if (pos_x > data->max_x || pos_y > data->max_y) {
872 			dev_dbg(input->dev.parent,
873 				"[%d] x=%d y=%d over max (%d, %d)",
874 				contact_num, pos_x, pos_y,
875 				data->max_x, data->max_y);
876 			return;
877 		}
878 
879 		/*
880 		 * To avoid treating large finger as palm, let's reduce the
881 		 * width x and y per trace.
882 		 */
883 		area_x = mk_x * (data->width_x - ETP_FWIDTH_REDUCE);
884 		area_y = mk_y * (data->width_y - ETP_FWIDTH_REDUCE);
885 
886 		major = max(area_x, area_y);
887 		minor = min(area_x, area_y);
888 
889 		scaled_pressure = pressure + data->pressure_adjustment;
890 
891 		if (scaled_pressure > ETP_MAX_PRESSURE)
892 			scaled_pressure = ETP_MAX_PRESSURE;
893 
894 		input_mt_slot(input, contact_num);
895 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
896 		input_report_abs(input, ABS_MT_POSITION_X, pos_x);
897 		input_report_abs(input, ABS_MT_POSITION_Y, data->max_y - pos_y);
898 		input_report_abs(input, ABS_MT_PRESSURE, scaled_pressure);
899 		input_report_abs(input, ABS_TOOL_WIDTH, mk_x);
900 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
901 		input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
902 	} else {
903 		input_mt_slot(input, contact_num);
904 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
905 	}
906 }
907 
908 static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
909 {
910 	struct input_dev *input = data->input;
911 	u8 *finger_data = &packet[ETP_FINGER_DATA_OFFSET];
912 	int i;
913 	u8 tp_info = packet[ETP_TOUCH_INFO_OFFSET];
914 	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
915 	bool contact_valid, hover_event;
916 
917 	hover_event = hover_info & 0x40;
918 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
919 		contact_valid = tp_info & (1U << (3 + i));
920 		elan_report_contact(data, i, contact_valid, finger_data);
921 
922 		if (contact_valid)
923 			finger_data += ETP_FINGER_DATA_LEN;
924 	}
925 
926 	input_report_key(input, BTN_LEFT, tp_info & 0x01);
927 	input_report_key(input, BTN_RIGHT, tp_info & 0x02);
928 	input_report_abs(input, ABS_DISTANCE, hover_event != 0);
929 	input_mt_report_pointer_emulation(input, true);
930 	input_sync(input);
931 }
932 
933 static irqreturn_t elan_isr(int irq, void *dev_id)
934 {
935 	struct elan_tp_data *data = dev_id;
936 	struct device *dev = &data->client->dev;
937 	int error;
938 	u8 report[ETP_MAX_REPORT_LEN];
939 
940 	/*
941 	 * When device is connected to i2c bus, when all IAP page writes
942 	 * complete, the driver will receive interrupt and must read
943 	 * 0000 to confirm that IAP is finished.
944 	*/
945 	if (data->in_fw_update) {
946 		complete(&data->fw_completion);
947 		goto out;
948 	}
949 
950 	error = data->ops->get_report(data->client, report);
951 	if (error)
952 		goto out;
953 
954 	if (report[ETP_REPORT_ID_OFFSET] != ETP_REPORT_ID)
955 		dev_err(dev, "invalid report id data (%x)\n",
956 			report[ETP_REPORT_ID_OFFSET]);
957 	else
958 		elan_report_absolute(data, report);
959 
960 out:
961 	return IRQ_HANDLED;
962 }
963 
964 /*
965  ******************************************************************
966  * Elan initialization functions
967  ******************************************************************
968  */
969 static int elan_setup_input_device(struct elan_tp_data *data)
970 {
971 	struct device *dev = &data->client->dev;
972 	struct input_dev *input;
973 	unsigned int max_width = max(data->width_x, data->width_y);
974 	unsigned int min_width = min(data->width_x, data->width_y);
975 	int error;
976 
977 	input = devm_input_allocate_device(dev);
978 	if (!input)
979 		return -ENOMEM;
980 
981 	input->name = "Elan Touchpad";
982 	input->id.bustype = BUS_I2C;
983 	input->id.vendor = ELAN_VENDOR_ID;
984 	input->id.product = data->product_id;
985 	input_set_drvdata(input, data);
986 
987 	error = input_mt_init_slots(input, ETP_MAX_FINGERS,
988 				    INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED);
989 	if (error) {
990 		dev_err(dev, "failed to initialize MT slots: %d\n", error);
991 		return error;
992 	}
993 
994 	__set_bit(EV_ABS, input->evbit);
995 	__set_bit(INPUT_PROP_POINTER, input->propbit);
996 	if (data->clickpad)
997 		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
998 	else
999 		__set_bit(BTN_RIGHT, input->keybit);
1000 	__set_bit(BTN_LEFT, input->keybit);
1001 
1002 	/* Set up ST parameters */
1003 	input_set_abs_params(input, ABS_X, 0, data->max_x, 0, 0);
1004 	input_set_abs_params(input, ABS_Y, 0, data->max_y, 0, 0);
1005 	input_abs_set_res(input, ABS_X, data->x_res);
1006 	input_abs_set_res(input, ABS_Y, data->y_res);
1007 	input_set_abs_params(input, ABS_PRESSURE, 0, ETP_MAX_PRESSURE, 0, 0);
1008 	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, ETP_FINGER_WIDTH, 0, 0);
1009 	input_set_abs_params(input, ABS_DISTANCE, 0, 1, 0, 0);
1010 
1011 	/* And MT parameters */
1012 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, data->max_x, 0, 0);
1013 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, data->max_y, 0, 0);
1014 	input_abs_set_res(input, ABS_MT_POSITION_X, data->x_res);
1015 	input_abs_set_res(input, ABS_MT_POSITION_Y, data->y_res);
1016 	input_set_abs_params(input, ABS_MT_PRESSURE, 0,
1017 			     ETP_MAX_PRESSURE, 0, 0);
1018 	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
1019 			     ETP_FINGER_WIDTH * max_width, 0, 0);
1020 	input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0,
1021 			     ETP_FINGER_WIDTH * min_width, 0, 0);
1022 
1023 	data->input = input;
1024 
1025 	return 0;
1026 }
1027 
1028 static void elan_disable_regulator(void *_data)
1029 {
1030 	struct elan_tp_data *data = _data;
1031 
1032 	regulator_disable(data->vcc);
1033 }
1034 
1035 static void elan_remove_sysfs_groups(void *_data)
1036 {
1037 	struct elan_tp_data *data = _data;
1038 
1039 	sysfs_remove_groups(&data->client->dev.kobj, elan_sysfs_groups);
1040 }
1041 
1042 static int elan_probe(struct i2c_client *client,
1043 		      const struct i2c_device_id *dev_id)
1044 {
1045 	const struct elan_transport_ops *transport_ops;
1046 	struct device *dev = &client->dev;
1047 	struct elan_tp_data *data;
1048 	unsigned long irqflags;
1049 	int error;
1050 
1051 	if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_I2C) &&
1052 	    i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1053 		transport_ops = &elan_i2c_ops;
1054 	} else if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) &&
1055 		   i2c_check_functionality(client->adapter,
1056 					   I2C_FUNC_SMBUS_BYTE_DATA |
1057 						I2C_FUNC_SMBUS_BLOCK_DATA |
1058 						I2C_FUNC_SMBUS_I2C_BLOCK)) {
1059 		transport_ops = &elan_smbus_ops;
1060 	} else {
1061 		dev_err(dev, "not a supported I2C/SMBus adapter\n");
1062 		return -EIO;
1063 	}
1064 
1065 	data = devm_kzalloc(dev, sizeof(struct elan_tp_data), GFP_KERNEL);
1066 	if (!data)
1067 		return -ENOMEM;
1068 
1069 	i2c_set_clientdata(client, data);
1070 
1071 	data->ops = transport_ops;
1072 	data->client = client;
1073 	init_completion(&data->fw_completion);
1074 	mutex_init(&data->sysfs_mutex);
1075 
1076 	data->vcc = devm_regulator_get(dev, "vcc");
1077 	if (IS_ERR(data->vcc)) {
1078 		error = PTR_ERR(data->vcc);
1079 		if (error != -EPROBE_DEFER)
1080 			dev_err(dev, "Failed to get 'vcc' regulator: %d\n",
1081 				error);
1082 		return error;
1083 	}
1084 
1085 	error = regulator_enable(data->vcc);
1086 	if (error) {
1087 		dev_err(dev, "Failed to enable regulator: %d\n", error);
1088 		return error;
1089 	}
1090 
1091 	error = devm_add_action(dev, elan_disable_regulator, data);
1092 	if (error) {
1093 		regulator_disable(data->vcc);
1094 		dev_err(dev, "Failed to add disable regulator action: %d\n",
1095 			error);
1096 		return error;
1097 	}
1098 
1099 	/* Make sure there is something at this address */
1100 	error = i2c_smbus_read_byte(client);
1101 	if (error < 0) {
1102 		dev_dbg(&client->dev, "nothing at this address: %d\n", error);
1103 		return -ENXIO;
1104 	}
1105 
1106 	/* Initialize the touchpad. */
1107 	error = elan_initialize(data);
1108 	if (error)
1109 		return error;
1110 
1111 	error = elan_query_device_info(data);
1112 	if (error)
1113 		return error;
1114 
1115 	error = elan_query_device_parameters(data);
1116 	if (error)
1117 		return error;
1118 
1119 	dev_info(dev,
1120 		 "Elan Touchpad: Module ID: 0x%04x, Firmware: 0x%04x, Sample: 0x%04x, IAP: 0x%04x\n",
1121 		 data->product_id,
1122 		 data->fw_version,
1123 		 data->sm_version,
1124 		 data->iap_version);
1125 
1126 	dev_dbg(dev,
1127 		"Elan Touchpad Extra Information:\n"
1128 		"    Max ABS X,Y:   %d,%d\n"
1129 		"    Width X,Y:   %d,%d\n"
1130 		"    Resolution X,Y:   %d,%d (dots/mm)\n"
1131 		"    ic type: 0x%x\n"
1132 		"    info pattern: 0x%x\n",
1133 		data->max_x, data->max_y,
1134 		data->width_x, data->width_y,
1135 		data->x_res, data->y_res,
1136 		data->ic_type, data->pattern);
1137 
1138 	/* Set up input device properties based on queried parameters. */
1139 	error = elan_setup_input_device(data);
1140 	if (error)
1141 		return error;
1142 
1143 	/*
1144 	 * Platform code (ACPI, DTS) should normally set up interrupt
1145 	 * for us, but in case it did not let's fall back to using falling
1146 	 * edge to be compatible with older Chromebooks.
1147 	 */
1148 	irqflags = irq_get_trigger_type(client->irq);
1149 	if (!irqflags)
1150 		irqflags = IRQF_TRIGGER_FALLING;
1151 
1152 	error = devm_request_threaded_irq(dev, client->irq, NULL, elan_isr,
1153 					  irqflags | IRQF_ONESHOT,
1154 					  client->name, data);
1155 	if (error) {
1156 		dev_err(dev, "cannot register irq=%d\n", client->irq);
1157 		return error;
1158 	}
1159 
1160 	error = sysfs_create_groups(&dev->kobj, elan_sysfs_groups);
1161 	if (error) {
1162 		dev_err(dev, "failed to create sysfs attributes: %d\n", error);
1163 		return error;
1164 	}
1165 
1166 	error = devm_add_action(dev, elan_remove_sysfs_groups, data);
1167 	if (error) {
1168 		elan_remove_sysfs_groups(data);
1169 		dev_err(dev, "Failed to add sysfs cleanup action: %d\n",
1170 			error);
1171 		return error;
1172 	}
1173 
1174 	error = input_register_device(data->input);
1175 	if (error) {
1176 		dev_err(dev, "failed to register input device: %d\n", error);
1177 		return error;
1178 	}
1179 
1180 	/*
1181 	 * Systems using device tree should set up wakeup via DTS,
1182 	 * the rest will configure device as wakeup source by default.
1183 	 */
1184 	if (!dev->of_node)
1185 		device_init_wakeup(dev, true);
1186 
1187 	return 0;
1188 }
1189 
1190 static int __maybe_unused elan_suspend(struct device *dev)
1191 {
1192 	struct i2c_client *client = to_i2c_client(dev);
1193 	struct elan_tp_data *data = i2c_get_clientdata(client);
1194 	int ret;
1195 
1196 	/*
1197 	 * We are taking the mutex to make sure sysfs operations are
1198 	 * complete before we attempt to bring the device into low[er]
1199 	 * power mode.
1200 	 */
1201 	ret = mutex_lock_interruptible(&data->sysfs_mutex);
1202 	if (ret)
1203 		return ret;
1204 
1205 	disable_irq(client->irq);
1206 
1207 	if (device_may_wakeup(dev)) {
1208 		ret = elan_sleep(data);
1209 		/* Enable wake from IRQ */
1210 		data->irq_wake = (enable_irq_wake(client->irq) == 0);
1211 	} else {
1212 		ret = elan_disable_power(data);
1213 	}
1214 
1215 	mutex_unlock(&data->sysfs_mutex);
1216 	return ret;
1217 }
1218 
1219 static int __maybe_unused elan_resume(struct device *dev)
1220 {
1221 	struct i2c_client *client = to_i2c_client(dev);
1222 	struct elan_tp_data *data = i2c_get_clientdata(client);
1223 	int error;
1224 
1225 	if (device_may_wakeup(dev) && data->irq_wake) {
1226 		disable_irq_wake(client->irq);
1227 		data->irq_wake = false;
1228 	}
1229 
1230 	error = elan_enable_power(data);
1231 	if (error) {
1232 		dev_err(dev, "power up when resuming failed: %d\n", error);
1233 		goto err;
1234 	}
1235 
1236 	error = elan_initialize(data);
1237 	if (error)
1238 		dev_err(dev, "initialize when resuming failed: %d\n", error);
1239 
1240 err:
1241 	enable_irq(data->client->irq);
1242 	return error;
1243 }
1244 
1245 static SIMPLE_DEV_PM_OPS(elan_pm_ops, elan_suspend, elan_resume);
1246 
1247 static const struct i2c_device_id elan_id[] = {
1248 	{ DRIVER_NAME, 0 },
1249 	{ },
1250 };
1251 MODULE_DEVICE_TABLE(i2c, elan_id);
1252 
1253 #ifdef CONFIG_ACPI
1254 static const struct acpi_device_id elan_acpi_id[] = {
1255 	{ "ELAN0000", 0 },
1256 	{ "ELAN0100", 0 },
1257 	{ "ELAN0600", 0 },
1258 	{ "ELAN0602", 0 },
1259 	{ "ELAN0605", 0 },
1260 	{ "ELAN0608", 0 },
1261 	{ "ELAN0609", 0 },
1262 	{ "ELAN060B", 0 },
1263 	{ "ELAN060C", 0 },
1264 	{ "ELAN0611", 0 },
1265 	{ "ELAN1000", 0 },
1266 	{ }
1267 };
1268 MODULE_DEVICE_TABLE(acpi, elan_acpi_id);
1269 #endif
1270 
1271 #ifdef CONFIG_OF
1272 static const struct of_device_id elan_of_match[] = {
1273 	{ .compatible = "elan,ekth3000" },
1274 	{ /* sentinel */ }
1275 };
1276 MODULE_DEVICE_TABLE(of, elan_of_match);
1277 #endif
1278 
1279 static struct i2c_driver elan_driver = {
1280 	.driver = {
1281 		.name	= DRIVER_NAME,
1282 		.pm	= &elan_pm_ops,
1283 		.acpi_match_table = ACPI_PTR(elan_acpi_id),
1284 		.of_match_table = of_match_ptr(elan_of_match),
1285 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1286 	},
1287 	.probe		= elan_probe,
1288 	.id_table	= elan_id,
1289 };
1290 
1291 module_i2c_driver(elan_driver);
1292 
1293 MODULE_AUTHOR("Duson Lin <dusonlin@emc.com.tw>");
1294 MODULE_DESCRIPTION("Elan I2C/SMBus Touchpad driver");
1295 MODULE_LICENSE("GPL");
1296