1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Elan I2C/SMBus Touchpad driver
4  *
5  * Copyright (c) 2013 ELAN Microelectronics Corp.
6  *
7  * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
8  * Author: KT Liao <kt.liao@emc.com.tw>
9  * Version: 1.6.3
10  *
11  * Based on cyapa driver:
12  * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
13  * copyright (c) 2011-2012 Google, Inc.
14  *
15  * Trademarks are the property of their respective owners.
16  */
17 
18 #include <linux/acpi.h>
19 #include <linux/delay.h>
20 #include <linux/device.h>
21 #include <linux/firmware.h>
22 #include <linux/i2c.h>
23 #include <linux/init.h>
24 #include <linux/input/mt.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/kernel.h>
30 #include <linux/sched.h>
31 #include <linux/input.h>
32 #include <linux/uaccess.h>
33 #include <linux/jiffies.h>
34 #include <linux/completion.h>
35 #include <linux/of.h>
36 #include <linux/property.h>
37 #include <linux/input/elan-i2c-ids.h>
38 #include <linux/regulator/consumer.h>
39 #include <asm/unaligned.h>
40 
41 #include "elan_i2c.h"
42 
43 #define DRIVER_NAME		"elan_i2c"
44 #define ELAN_VENDOR_ID		0x04f3
45 #define ETP_MAX_PRESSURE	255
46 #define ETP_FWIDTH_REDUCE	90
47 #define ETP_FINGER_WIDTH	15
48 #define ETP_RETRY_COUNT		3
49 
50 #define ETP_MAX_FINGERS		5
51 #define ETP_FINGER_DATA_LEN	5
52 #define ETP_REPORT_ID		0x5D
53 #define ETP_TP_REPORT_ID	0x5E
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 input_dev	*tp_input; /* trackpoint input node */
65 	struct regulator	*vcc;
66 
67 	const struct elan_transport_ops *ops;
68 
69 	/* for fw update */
70 	struct completion	fw_completion;
71 	bool			in_fw_update;
72 
73 	struct mutex		sysfs_mutex;
74 
75 	unsigned int		max_x;
76 	unsigned int		max_y;
77 	unsigned int		width_x;
78 	unsigned int		width_y;
79 	unsigned int		x_res;
80 	unsigned int		y_res;
81 
82 	u8			pattern;
83 	u16			product_id;
84 	u8			fw_version;
85 	u8			sm_version;
86 	u8			iap_version;
87 	u16			fw_checksum;
88 	int			pressure_adjustment;
89 	u8			mode;
90 	u16			ic_type;
91 	u16			fw_validpage_count;
92 	u16			fw_signature_address;
93 
94 	bool			irq_wake;
95 
96 	u8			min_baseline;
97 	u8			max_baseline;
98 	bool			baseline_ready;
99 	u8			clickpad;
100 	bool			middle_button;
101 };
102 
103 static int elan_get_fwinfo(u16 ic_type, u16 *validpage_count,
104 			   u16 *signature_address)
105 {
106 	switch (ic_type) {
107 	case 0x00:
108 	case 0x06:
109 	case 0x08:
110 		*validpage_count = 512;
111 		break;
112 	case 0x03:
113 	case 0x07:
114 	case 0x09:
115 	case 0x0A:
116 	case 0x0B:
117 	case 0x0C:
118 		*validpage_count = 768;
119 		break;
120 	case 0x0D:
121 		*validpage_count = 896;
122 		break;
123 	case 0x0E:
124 		*validpage_count = 640;
125 		break;
126 	case 0x10:
127 		*validpage_count = 1024;
128 		break;
129 	default:
130 		/* unknown ic type clear value */
131 		*validpage_count = 0;
132 		*signature_address = 0;
133 		return -ENXIO;
134 	}
135 
136 	*signature_address =
137 		(*validpage_count * ETP_FW_PAGE_SIZE) - ETP_FW_SIGNATURE_SIZE;
138 
139 	return 0;
140 }
141 
142 static int elan_enable_power(struct elan_tp_data *data)
143 {
144 	int repeat = ETP_RETRY_COUNT;
145 	int error;
146 
147 	error = regulator_enable(data->vcc);
148 	if (error) {
149 		dev_err(&data->client->dev,
150 			"failed to enable regulator: %d\n", error);
151 		return error;
152 	}
153 
154 	do {
155 		error = data->ops->power_control(data->client, true);
156 		if (error >= 0)
157 			return 0;
158 
159 		msleep(30);
160 	} while (--repeat > 0);
161 
162 	dev_err(&data->client->dev, "failed to enable power: %d\n", error);
163 	return error;
164 }
165 
166 static int elan_disable_power(struct elan_tp_data *data)
167 {
168 	int repeat = ETP_RETRY_COUNT;
169 	int error;
170 
171 	do {
172 		error = data->ops->power_control(data->client, false);
173 		if (!error) {
174 			error = regulator_disable(data->vcc);
175 			if (error) {
176 				dev_err(&data->client->dev,
177 					"failed to disable regulator: %d\n",
178 					error);
179 				/* Attempt to power the chip back up */
180 				data->ops->power_control(data->client, true);
181 				break;
182 			}
183 
184 			return 0;
185 		}
186 
187 		msleep(30);
188 	} while (--repeat > 0);
189 
190 	dev_err(&data->client->dev, "failed to disable power: %d\n", error);
191 	return error;
192 }
193 
194 static int elan_sleep(struct elan_tp_data *data)
195 {
196 	int repeat = ETP_RETRY_COUNT;
197 	int error;
198 
199 	do {
200 		error = data->ops->sleep_control(data->client, true);
201 		if (!error)
202 			return 0;
203 
204 		msleep(30);
205 	} while (--repeat > 0);
206 
207 	return error;
208 }
209 
210 static int elan_query_product(struct elan_tp_data *data)
211 {
212 	int error;
213 
214 	error = data->ops->get_product_id(data->client, &data->product_id);
215 	if (error)
216 		return error;
217 
218 	error = data->ops->get_sm_version(data->client, &data->ic_type,
219 					  &data->sm_version, &data->clickpad);
220 	if (error)
221 		return error;
222 
223 	return 0;
224 }
225 
226 static int elan_check_ASUS_special_fw(struct elan_tp_data *data)
227 {
228 	if (data->ic_type == 0x0E) {
229 		switch (data->product_id) {
230 		case 0x05 ... 0x07:
231 		case 0x09:
232 		case 0x13:
233 			return true;
234 		}
235 	} else if (data->ic_type == 0x08 && data->product_id == 0x26) {
236 		/* ASUS EeeBook X205TA */
237 		return true;
238 	}
239 
240 	return false;
241 }
242 
243 static int __elan_initialize(struct elan_tp_data *data)
244 {
245 	struct i2c_client *client = data->client;
246 	bool woken_up = false;
247 	int error;
248 
249 	error = data->ops->initialize(client);
250 	if (error) {
251 		dev_err(&client->dev, "device initialize failed: %d\n", error);
252 		return error;
253 	}
254 
255 	error = elan_query_product(data);
256 	if (error)
257 		return error;
258 
259 	/*
260 	 * Some ASUS devices were shipped with firmware that requires
261 	 * touchpads to be woken up first, before attempting to switch
262 	 * them into absolute reporting mode.
263 	 */
264 	if (elan_check_ASUS_special_fw(data)) {
265 		error = data->ops->sleep_control(client, false);
266 		if (error) {
267 			dev_err(&client->dev,
268 				"failed to wake device up: %d\n", error);
269 			return error;
270 		}
271 
272 		msleep(200);
273 		woken_up = true;
274 	}
275 
276 	data->mode |= ETP_ENABLE_ABS;
277 	error = data->ops->set_mode(client, data->mode);
278 	if (error) {
279 		dev_err(&client->dev,
280 			"failed to switch to absolute mode: %d\n", error);
281 		return error;
282 	}
283 
284 	if (!woken_up) {
285 		error = data->ops->sleep_control(client, false);
286 		if (error) {
287 			dev_err(&client->dev,
288 				"failed to wake device up: %d\n", error);
289 			return error;
290 		}
291 	}
292 
293 	return 0;
294 }
295 
296 static int elan_initialize(struct elan_tp_data *data)
297 {
298 	int repeat = ETP_RETRY_COUNT;
299 	int error;
300 
301 	do {
302 		error = __elan_initialize(data);
303 		if (!error)
304 			return 0;
305 
306 		msleep(30);
307 	} while (--repeat > 0);
308 
309 	return error;
310 }
311 
312 static int elan_query_device_info(struct elan_tp_data *data)
313 {
314 	int error;
315 	u16 ic_type;
316 
317 	error = data->ops->get_version(data->client, false, &data->fw_version);
318 	if (error)
319 		return error;
320 
321 	error = data->ops->get_checksum(data->client, false,
322 					&data->fw_checksum);
323 	if (error)
324 		return error;
325 
326 	error = data->ops->get_version(data->client, true, &data->iap_version);
327 	if (error)
328 		return error;
329 
330 	error = data->ops->get_pressure_adjustment(data->client,
331 						   &data->pressure_adjustment);
332 	if (error)
333 		return error;
334 
335 	error = data->ops->get_pattern(data->client, &data->pattern);
336 	if (error)
337 		return error;
338 
339 	if (data->pattern == 0x01)
340 		ic_type = data->ic_type;
341 	else
342 		ic_type = data->iap_version;
343 
344 	error = elan_get_fwinfo(ic_type, &data->fw_validpage_count,
345 				&data->fw_signature_address);
346 	if (error)
347 		dev_warn(&data->client->dev,
348 			 "unexpected iap version %#04x (ic type: %#04x), firmware update will not work\n",
349 			 data->iap_version, data->ic_type);
350 
351 	return 0;
352 }
353 
354 static unsigned int elan_convert_resolution(u8 val)
355 {
356 	/*
357 	 * (value from firmware) * 10 + 790 = dpi
358 	 *
359 	 * We also have to convert dpi to dots/mm (*10/254 to avoid floating
360 	 * point).
361 	 */
362 
363 	return ((int)(char)val * 10 + 790) * 10 / 254;
364 }
365 
366 static int elan_query_device_parameters(struct elan_tp_data *data)
367 {
368 	struct i2c_client *client = data->client;
369 	unsigned int x_traces, y_traces;
370 	u32 x_mm, y_mm;
371 	u8 hw_x_res, hw_y_res;
372 	int error;
373 
374 	if (device_property_read_u32(&client->dev,
375 				     "touchscreen-size-x", &data->max_x) ||
376 	    device_property_read_u32(&client->dev,
377 				     "touchscreen-size-y", &data->max_y)) {
378 		error = data->ops->get_max(data->client,
379 					   &data->max_x,
380 					   &data->max_y);
381 		if (error)
382 			return error;
383 	} else {
384 		/* size is the maximum + 1 */
385 		--data->max_x;
386 		--data->max_y;
387 	}
388 
389 	if (device_property_read_u32(&client->dev,
390 				     "elan,x_traces",
391 				     &x_traces) ||
392 	    device_property_read_u32(&client->dev,
393 				     "elan,y_traces",
394 				     &y_traces)) {
395 		error = data->ops->get_num_traces(data->client,
396 						  &x_traces, &y_traces);
397 		if (error)
398 			return error;
399 	}
400 	data->width_x = data->max_x / x_traces;
401 	data->width_y = data->max_y / y_traces;
402 
403 	if (device_property_read_u32(&client->dev,
404 				     "touchscreen-x-mm", &x_mm) ||
405 	    device_property_read_u32(&client->dev,
406 				     "touchscreen-y-mm", &y_mm)) {
407 		error = data->ops->get_resolution(data->client,
408 						  &hw_x_res, &hw_y_res);
409 		if (error)
410 			return error;
411 
412 		data->x_res = elan_convert_resolution(hw_x_res);
413 		data->y_res = elan_convert_resolution(hw_y_res);
414 	} else {
415 		data->x_res = (data->max_x + 1) / x_mm;
416 		data->y_res = (data->max_y + 1) / y_mm;
417 	}
418 
419 	if (device_property_read_bool(&client->dev, "elan,clickpad"))
420 		data->clickpad = 1;
421 
422 	if (device_property_read_bool(&client->dev, "elan,middle-button"))
423 		data->middle_button = true;
424 
425 	return 0;
426 }
427 
428 /*
429  **********************************************************
430  * IAP firmware updater related routines
431  **********************************************************
432  */
433 static int elan_write_fw_block(struct elan_tp_data *data,
434 			       const u8 *page, u16 checksum, int idx)
435 {
436 	int retry = ETP_RETRY_COUNT;
437 	int error;
438 
439 	do {
440 		error = data->ops->write_fw_block(data->client,
441 						  page, checksum, idx);
442 		if (!error)
443 			return 0;
444 
445 		dev_dbg(&data->client->dev,
446 			"IAP retrying page %d (error: %d)\n", idx, error);
447 	} while (--retry > 0);
448 
449 	return error;
450 }
451 
452 static int __elan_update_firmware(struct elan_tp_data *data,
453 				  const struct firmware *fw)
454 {
455 	struct i2c_client *client = data->client;
456 	struct device *dev = &client->dev;
457 	int i, j;
458 	int error;
459 	u16 iap_start_addr;
460 	u16 boot_page_count;
461 	u16 sw_checksum = 0, fw_checksum = 0;
462 
463 	error = data->ops->prepare_fw_update(client);
464 	if (error)
465 		return error;
466 
467 	iap_start_addr = get_unaligned_le16(&fw->data[ETP_IAP_START_ADDR * 2]);
468 
469 	boot_page_count = (iap_start_addr * 2) / ETP_FW_PAGE_SIZE;
470 	for (i = boot_page_count; i < data->fw_validpage_count; i++) {
471 		u16 checksum = 0;
472 		const u8 *page = &fw->data[i * ETP_FW_PAGE_SIZE];
473 
474 		for (j = 0; j < ETP_FW_PAGE_SIZE; j += 2)
475 			checksum += ((page[j + 1] << 8) | page[j]);
476 
477 		error = elan_write_fw_block(data, page, checksum, i);
478 		if (error) {
479 			dev_err(dev, "write page %d fail: %d\n", i, error);
480 			return error;
481 		}
482 
483 		sw_checksum += checksum;
484 	}
485 
486 	/* Wait WDT reset and power on reset */
487 	msleep(600);
488 
489 	error = data->ops->finish_fw_update(client, &data->fw_completion);
490 	if (error)
491 		return error;
492 
493 	error = data->ops->get_checksum(client, true, &fw_checksum);
494 	if (error)
495 		return error;
496 
497 	if (sw_checksum != fw_checksum) {
498 		dev_err(dev, "checksum diff sw=[%04X], fw=[%04X]\n",
499 			sw_checksum, fw_checksum);
500 		return -EIO;
501 	}
502 
503 	return 0;
504 }
505 
506 static int elan_update_firmware(struct elan_tp_data *data,
507 				const struct firmware *fw)
508 {
509 	struct i2c_client *client = data->client;
510 	int retval;
511 
512 	dev_dbg(&client->dev, "Starting firmware update....\n");
513 
514 	disable_irq(client->irq);
515 	data->in_fw_update = true;
516 
517 	retval = __elan_update_firmware(data, fw);
518 	if (retval) {
519 		dev_err(&client->dev, "firmware update failed: %d\n", retval);
520 		data->ops->iap_reset(client);
521 	} else {
522 		/* Reinitialize TP after fw is updated */
523 		elan_initialize(data);
524 		elan_query_device_info(data);
525 	}
526 
527 	data->in_fw_update = false;
528 	enable_irq(client->irq);
529 
530 	return retval;
531 }
532 
533 /*
534  *******************************************************************
535  * SYSFS attributes
536  *******************************************************************
537  */
538 static ssize_t elan_sysfs_read_fw_checksum(struct device *dev,
539 					   struct device_attribute *attr,
540 					   char *buf)
541 {
542 	struct i2c_client *client = to_i2c_client(dev);
543 	struct elan_tp_data *data = i2c_get_clientdata(client);
544 
545 	return sprintf(buf, "0x%04x\n", data->fw_checksum);
546 }
547 
548 static ssize_t elan_sysfs_read_product_id(struct device *dev,
549 					 struct device_attribute *attr,
550 					 char *buf)
551 {
552 	struct i2c_client *client = to_i2c_client(dev);
553 	struct elan_tp_data *data = i2c_get_clientdata(client);
554 
555 	return sprintf(buf, ETP_PRODUCT_ID_FORMAT_STRING "\n",
556 		       data->product_id);
557 }
558 
559 static ssize_t elan_sysfs_read_fw_ver(struct device *dev,
560 				      struct device_attribute *attr,
561 				      char *buf)
562 {
563 	struct i2c_client *client = to_i2c_client(dev);
564 	struct elan_tp_data *data = i2c_get_clientdata(client);
565 
566 	return sprintf(buf, "%d.0\n", data->fw_version);
567 }
568 
569 static ssize_t elan_sysfs_read_sm_ver(struct device *dev,
570 				      struct device_attribute *attr,
571 				      char *buf)
572 {
573 	struct i2c_client *client = to_i2c_client(dev);
574 	struct elan_tp_data *data = i2c_get_clientdata(client);
575 
576 	return sprintf(buf, "%d.0\n", data->sm_version);
577 }
578 
579 static ssize_t elan_sysfs_read_iap_ver(struct device *dev,
580 				       struct device_attribute *attr,
581 				       char *buf)
582 {
583 	struct i2c_client *client = to_i2c_client(dev);
584 	struct elan_tp_data *data = i2c_get_clientdata(client);
585 
586 	return sprintf(buf, "%d.0\n", data->iap_version);
587 }
588 
589 static ssize_t elan_sysfs_update_fw(struct device *dev,
590 				    struct device_attribute *attr,
591 				    const char *buf, size_t count)
592 {
593 	struct elan_tp_data *data = dev_get_drvdata(dev);
594 	const struct firmware *fw;
595 	char *fw_name;
596 	int error;
597 	const u8 *fw_signature;
598 	static const u8 signature[] = {0xAA, 0x55, 0xCC, 0x33, 0xFF, 0xFF};
599 
600 	if (data->fw_validpage_count == 0)
601 		return -EINVAL;
602 
603 	/* Look for a firmware with the product id appended. */
604 	fw_name = kasprintf(GFP_KERNEL, ETP_FW_NAME, data->product_id);
605 	if (!fw_name) {
606 		dev_err(dev, "failed to allocate memory for firmware name\n");
607 		return -ENOMEM;
608 	}
609 
610 	dev_info(dev, "requesting fw '%s'\n", fw_name);
611 	error = request_firmware(&fw, fw_name, dev);
612 	kfree(fw_name);
613 	if (error) {
614 		dev_err(dev, "failed to request firmware: %d\n", error);
615 		return error;
616 	}
617 
618 	/* Firmware file must match signature data */
619 	fw_signature = &fw->data[data->fw_signature_address];
620 	if (memcmp(fw_signature, signature, sizeof(signature)) != 0) {
621 		dev_err(dev, "signature mismatch (expected %*ph, got %*ph)\n",
622 			(int)sizeof(signature), signature,
623 			(int)sizeof(signature), fw_signature);
624 		error = -EBADF;
625 		goto out_release_fw;
626 	}
627 
628 	error = mutex_lock_interruptible(&data->sysfs_mutex);
629 	if (error)
630 		goto out_release_fw;
631 
632 	error = elan_update_firmware(data, fw);
633 
634 	mutex_unlock(&data->sysfs_mutex);
635 
636 out_release_fw:
637 	release_firmware(fw);
638 	return error ?: count;
639 }
640 
641 static ssize_t calibrate_store(struct device *dev,
642 			       struct device_attribute *attr,
643 			       const char *buf, size_t count)
644 {
645 	struct i2c_client *client = to_i2c_client(dev);
646 	struct elan_tp_data *data = i2c_get_clientdata(client);
647 	int tries = 20;
648 	int retval;
649 	int error;
650 	u8 val[ETP_CALIBRATE_MAX_LEN];
651 
652 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
653 	if (retval)
654 		return retval;
655 
656 	disable_irq(client->irq);
657 
658 	data->mode |= ETP_ENABLE_CALIBRATE;
659 	retval = data->ops->set_mode(client, data->mode);
660 	if (retval) {
661 		dev_err(dev, "failed to enable calibration mode: %d\n",
662 			retval);
663 		goto out;
664 	}
665 
666 	retval = data->ops->calibrate(client);
667 	if (retval) {
668 		dev_err(dev, "failed to start calibration: %d\n",
669 			retval);
670 		goto out_disable_calibrate;
671 	}
672 
673 	val[0] = 0xff;
674 	do {
675 		/* Wait 250ms before checking if calibration has completed. */
676 		msleep(250);
677 
678 		retval = data->ops->calibrate_result(client, val);
679 		if (retval)
680 			dev_err(dev, "failed to check calibration result: %d\n",
681 				retval);
682 		else if (val[0] == 0)
683 			break; /* calibration done */
684 
685 	} while (--tries);
686 
687 	if (tries == 0) {
688 		dev_err(dev, "failed to calibrate. Timeout.\n");
689 		retval = -ETIMEDOUT;
690 	}
691 
692 out_disable_calibrate:
693 	data->mode &= ~ETP_ENABLE_CALIBRATE;
694 	error = data->ops->set_mode(data->client, data->mode);
695 	if (error) {
696 		dev_err(dev, "failed to disable calibration mode: %d\n",
697 			error);
698 		if (!retval)
699 			retval = error;
700 	}
701 out:
702 	enable_irq(client->irq);
703 	mutex_unlock(&data->sysfs_mutex);
704 	return retval ?: count;
705 }
706 
707 static ssize_t elan_sysfs_read_mode(struct device *dev,
708 				    struct device_attribute *attr,
709 				    char *buf)
710 {
711 	struct i2c_client *client = to_i2c_client(dev);
712 	struct elan_tp_data *data = i2c_get_clientdata(client);
713 	int error;
714 	enum tp_mode mode;
715 
716 	error = mutex_lock_interruptible(&data->sysfs_mutex);
717 	if (error)
718 		return error;
719 
720 	error = data->ops->iap_get_mode(data->client, &mode);
721 
722 	mutex_unlock(&data->sysfs_mutex);
723 
724 	if (error)
725 		return error;
726 
727 	return sprintf(buf, "%d\n", (int)mode);
728 }
729 
730 static DEVICE_ATTR(product_id, S_IRUGO, elan_sysfs_read_product_id, NULL);
731 static DEVICE_ATTR(firmware_version, S_IRUGO, elan_sysfs_read_fw_ver, NULL);
732 static DEVICE_ATTR(sample_version, S_IRUGO, elan_sysfs_read_sm_ver, NULL);
733 static DEVICE_ATTR(iap_version, S_IRUGO, elan_sysfs_read_iap_ver, NULL);
734 static DEVICE_ATTR(fw_checksum, S_IRUGO, elan_sysfs_read_fw_checksum, NULL);
735 static DEVICE_ATTR(mode, S_IRUGO, elan_sysfs_read_mode, NULL);
736 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, elan_sysfs_update_fw);
737 
738 static DEVICE_ATTR_WO(calibrate);
739 
740 static struct attribute *elan_sysfs_entries[] = {
741 	&dev_attr_product_id.attr,
742 	&dev_attr_firmware_version.attr,
743 	&dev_attr_sample_version.attr,
744 	&dev_attr_iap_version.attr,
745 	&dev_attr_fw_checksum.attr,
746 	&dev_attr_calibrate.attr,
747 	&dev_attr_mode.attr,
748 	&dev_attr_update_fw.attr,
749 	NULL,
750 };
751 
752 static const struct attribute_group elan_sysfs_group = {
753 	.attrs = elan_sysfs_entries,
754 };
755 
756 static ssize_t acquire_store(struct device *dev, struct device_attribute *attr,
757 			     const char *buf, size_t count)
758 {
759 	struct i2c_client *client = to_i2c_client(dev);
760 	struct elan_tp_data *data = i2c_get_clientdata(client);
761 	int error;
762 	int retval;
763 
764 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
765 	if (retval)
766 		return retval;
767 
768 	disable_irq(client->irq);
769 
770 	data->baseline_ready = false;
771 
772 	data->mode |= ETP_ENABLE_CALIBRATE;
773 	retval = data->ops->set_mode(data->client, data->mode);
774 	if (retval) {
775 		dev_err(dev, "Failed to enable calibration mode to get baseline: %d\n",
776 			retval);
777 		goto out;
778 	}
779 
780 	msleep(250);
781 
782 	retval = data->ops->get_baseline_data(data->client, true,
783 					      &data->max_baseline);
784 	if (retval) {
785 		dev_err(dev, "Failed to read max baseline form device: %d\n",
786 			retval);
787 		goto out_disable_calibrate;
788 	}
789 
790 	retval = data->ops->get_baseline_data(data->client, false,
791 					      &data->min_baseline);
792 	if (retval) {
793 		dev_err(dev, "Failed to read min baseline form device: %d\n",
794 			retval);
795 		goto out_disable_calibrate;
796 	}
797 
798 	data->baseline_ready = true;
799 
800 out_disable_calibrate:
801 	data->mode &= ~ETP_ENABLE_CALIBRATE;
802 	error = data->ops->set_mode(data->client, data->mode);
803 	if (error) {
804 		dev_err(dev, "Failed to disable calibration mode after acquiring baseline: %d\n",
805 			error);
806 		if (!retval)
807 			retval = error;
808 	}
809 out:
810 	enable_irq(client->irq);
811 	mutex_unlock(&data->sysfs_mutex);
812 	return retval ?: count;
813 }
814 
815 static ssize_t min_show(struct device *dev,
816 			struct device_attribute *attr, char *buf)
817 {
818 	struct i2c_client *client = to_i2c_client(dev);
819 	struct elan_tp_data *data = i2c_get_clientdata(client);
820 	int retval;
821 
822 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
823 	if (retval)
824 		return retval;
825 
826 	if (!data->baseline_ready) {
827 		retval = -ENODATA;
828 		goto out;
829 	}
830 
831 	retval = snprintf(buf, PAGE_SIZE, "%d", data->min_baseline);
832 
833 out:
834 	mutex_unlock(&data->sysfs_mutex);
835 	return retval;
836 }
837 
838 static ssize_t max_show(struct device *dev,
839 			struct device_attribute *attr, char *buf)
840 {
841 	struct i2c_client *client = to_i2c_client(dev);
842 	struct elan_tp_data *data = i2c_get_clientdata(client);
843 	int retval;
844 
845 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
846 	if (retval)
847 		return retval;
848 
849 	if (!data->baseline_ready) {
850 		retval = -ENODATA;
851 		goto out;
852 	}
853 
854 	retval = snprintf(buf, PAGE_SIZE, "%d", data->max_baseline);
855 
856 out:
857 	mutex_unlock(&data->sysfs_mutex);
858 	return retval;
859 }
860 
861 
862 static DEVICE_ATTR_WO(acquire);
863 static DEVICE_ATTR_RO(min);
864 static DEVICE_ATTR_RO(max);
865 
866 static struct attribute *elan_baseline_sysfs_entries[] = {
867 	&dev_attr_acquire.attr,
868 	&dev_attr_min.attr,
869 	&dev_attr_max.attr,
870 	NULL,
871 };
872 
873 static const struct attribute_group elan_baseline_sysfs_group = {
874 	.name = "baseline",
875 	.attrs = elan_baseline_sysfs_entries,
876 };
877 
878 static const struct attribute_group *elan_sysfs_groups[] = {
879 	&elan_sysfs_group,
880 	&elan_baseline_sysfs_group,
881 	NULL
882 };
883 
884 /*
885  ******************************************************************
886  * Elan isr functions
887  ******************************************************************
888  */
889 static void elan_report_contact(struct elan_tp_data *data,
890 				int contact_num, bool contact_valid,
891 				u8 *finger_data)
892 {
893 	struct input_dev *input = data->input;
894 	unsigned int pos_x, pos_y;
895 	unsigned int pressure, mk_x, mk_y;
896 	unsigned int area_x, area_y, major, minor;
897 	unsigned int scaled_pressure;
898 
899 	if (contact_valid) {
900 		pos_x = ((finger_data[0] & 0xf0) << 4) |
901 						finger_data[1];
902 		pos_y = ((finger_data[0] & 0x0f) << 8) |
903 						finger_data[2];
904 		mk_x = (finger_data[3] & 0x0f);
905 		mk_y = (finger_data[3] >> 4);
906 		pressure = finger_data[4];
907 
908 		if (pos_x > data->max_x || pos_y > data->max_y) {
909 			dev_dbg(input->dev.parent,
910 				"[%d] x=%d y=%d over max (%d, %d)",
911 				contact_num, pos_x, pos_y,
912 				data->max_x, data->max_y);
913 			return;
914 		}
915 
916 		/*
917 		 * To avoid treating large finger as palm, let's reduce the
918 		 * width x and y per trace.
919 		 */
920 		area_x = mk_x * (data->width_x - ETP_FWIDTH_REDUCE);
921 		area_y = mk_y * (data->width_y - ETP_FWIDTH_REDUCE);
922 
923 		major = max(area_x, area_y);
924 		minor = min(area_x, area_y);
925 
926 		scaled_pressure = pressure + data->pressure_adjustment;
927 
928 		if (scaled_pressure > ETP_MAX_PRESSURE)
929 			scaled_pressure = ETP_MAX_PRESSURE;
930 
931 		input_mt_slot(input, contact_num);
932 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
933 		input_report_abs(input, ABS_MT_POSITION_X, pos_x);
934 		input_report_abs(input, ABS_MT_POSITION_Y, data->max_y - pos_y);
935 		input_report_abs(input, ABS_MT_PRESSURE, scaled_pressure);
936 		input_report_abs(input, ABS_TOOL_WIDTH, mk_x);
937 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
938 		input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
939 	} else {
940 		input_mt_slot(input, contact_num);
941 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
942 	}
943 }
944 
945 static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
946 {
947 	struct input_dev *input = data->input;
948 	u8 *finger_data = &packet[ETP_FINGER_DATA_OFFSET];
949 	int i;
950 	u8 tp_info = packet[ETP_TOUCH_INFO_OFFSET];
951 	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
952 	bool contact_valid, hover_event;
953 
954 	hover_event = hover_info & 0x40;
955 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
956 		contact_valid = tp_info & (1U << (3 + i));
957 		elan_report_contact(data, i, contact_valid, finger_data);
958 
959 		if (contact_valid)
960 			finger_data += ETP_FINGER_DATA_LEN;
961 	}
962 
963 	input_report_key(input, BTN_LEFT,   tp_info & BIT(0));
964 	input_report_key(input, BTN_MIDDLE, tp_info & BIT(2));
965 	input_report_key(input, BTN_RIGHT,  tp_info & BIT(1));
966 	input_report_abs(input, ABS_DISTANCE, hover_event != 0);
967 	input_mt_report_pointer_emulation(input, true);
968 	input_sync(input);
969 }
970 
971 static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
972 {
973 	struct input_dev *input = data->tp_input;
974 	u8 *packet = &report[ETP_REPORT_ID_OFFSET + 1];
975 	int x, y;
976 
977 	if (!data->tp_input) {
978 		dev_warn_once(&data->client->dev,
979 			      "received a trackpoint report while no trackpoint device has been created. Please report upstream.\n");
980 		return;
981 	}
982 
983 	input_report_key(input, BTN_LEFT, packet[0] & 0x01);
984 	input_report_key(input, BTN_RIGHT, packet[0] & 0x02);
985 	input_report_key(input, BTN_MIDDLE, packet[0] & 0x04);
986 
987 	if ((packet[3] & 0x0F) == 0x06) {
988 		x = packet[4] - (int)((packet[1] ^ 0x80) << 1);
989 		y = (int)((packet[2] ^ 0x80) << 1) - packet[5];
990 
991 		input_report_rel(input, REL_X, x);
992 		input_report_rel(input, REL_Y, y);
993 	}
994 
995 	input_sync(input);
996 }
997 
998 static irqreturn_t elan_isr(int irq, void *dev_id)
999 {
1000 	struct elan_tp_data *data = dev_id;
1001 	struct device *dev = &data->client->dev;
1002 	int error;
1003 	u8 report[ETP_MAX_REPORT_LEN];
1004 
1005 	/*
1006 	 * When device is connected to i2c bus, when all IAP page writes
1007 	 * complete, the driver will receive interrupt and must read
1008 	 * 0000 to confirm that IAP is finished.
1009 	*/
1010 	if (data->in_fw_update) {
1011 		complete(&data->fw_completion);
1012 		goto out;
1013 	}
1014 
1015 	error = data->ops->get_report(data->client, report);
1016 	if (error)
1017 		goto out;
1018 
1019 	pm_wakeup_event(dev, 0);
1020 
1021 	switch (report[ETP_REPORT_ID_OFFSET]) {
1022 	case ETP_REPORT_ID:
1023 		elan_report_absolute(data, report);
1024 		break;
1025 	case ETP_TP_REPORT_ID:
1026 		elan_report_trackpoint(data, report);
1027 		break;
1028 	default:
1029 		dev_err(dev, "invalid report id data (%x)\n",
1030 			report[ETP_REPORT_ID_OFFSET]);
1031 	}
1032 
1033 out:
1034 	return IRQ_HANDLED;
1035 }
1036 
1037 /*
1038  ******************************************************************
1039  * Elan initialization functions
1040  ******************************************************************
1041  */
1042 
1043 static int elan_setup_trackpoint_input_device(struct elan_tp_data *data)
1044 {
1045 	struct device *dev = &data->client->dev;
1046 	struct input_dev *input;
1047 
1048 	input = devm_input_allocate_device(dev);
1049 	if (!input)
1050 		return -ENOMEM;
1051 
1052 	input->name = "Elan TrackPoint";
1053 	input->id.bustype = BUS_I2C;
1054 	input->id.vendor = ELAN_VENDOR_ID;
1055 	input->id.product = data->product_id;
1056 	input_set_drvdata(input, data);
1057 
1058 	input_set_capability(input, EV_REL, REL_X);
1059 	input_set_capability(input, EV_REL, REL_Y);
1060 	input_set_capability(input, EV_KEY, BTN_LEFT);
1061 	input_set_capability(input, EV_KEY, BTN_RIGHT);
1062 	input_set_capability(input, EV_KEY, BTN_MIDDLE);
1063 
1064 	__set_bit(INPUT_PROP_POINTER, input->propbit);
1065 	__set_bit(INPUT_PROP_POINTING_STICK, input->propbit);
1066 
1067 	data->tp_input = input;
1068 
1069 	return 0;
1070 }
1071 
1072 static int elan_setup_input_device(struct elan_tp_data *data)
1073 {
1074 	struct device *dev = &data->client->dev;
1075 	struct input_dev *input;
1076 	unsigned int max_width = max(data->width_x, data->width_y);
1077 	unsigned int min_width = min(data->width_x, data->width_y);
1078 	int error;
1079 
1080 	input = devm_input_allocate_device(dev);
1081 	if (!input)
1082 		return -ENOMEM;
1083 
1084 	input->name = "Elan Touchpad";
1085 	input->id.bustype = BUS_I2C;
1086 	input->id.vendor = ELAN_VENDOR_ID;
1087 	input->id.product = data->product_id;
1088 	input_set_drvdata(input, data);
1089 
1090 	error = input_mt_init_slots(input, ETP_MAX_FINGERS,
1091 				    INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED);
1092 	if (error) {
1093 		dev_err(dev, "failed to initialize MT slots: %d\n", error);
1094 		return error;
1095 	}
1096 
1097 	__set_bit(EV_ABS, input->evbit);
1098 	__set_bit(INPUT_PROP_POINTER, input->propbit);
1099 	if (data->clickpad) {
1100 		__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
1101 	} else {
1102 		__set_bit(BTN_RIGHT, input->keybit);
1103 		if (data->middle_button)
1104 			__set_bit(BTN_MIDDLE, input->keybit);
1105 	}
1106 	__set_bit(BTN_LEFT, input->keybit);
1107 
1108 	/* Set up ST parameters */
1109 	input_set_abs_params(input, ABS_X, 0, data->max_x, 0, 0);
1110 	input_set_abs_params(input, ABS_Y, 0, data->max_y, 0, 0);
1111 	input_abs_set_res(input, ABS_X, data->x_res);
1112 	input_abs_set_res(input, ABS_Y, data->y_res);
1113 	input_set_abs_params(input, ABS_PRESSURE, 0, ETP_MAX_PRESSURE, 0, 0);
1114 	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, ETP_FINGER_WIDTH, 0, 0);
1115 	input_set_abs_params(input, ABS_DISTANCE, 0, 1, 0, 0);
1116 
1117 	/* And MT parameters */
1118 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, data->max_x, 0, 0);
1119 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, data->max_y, 0, 0);
1120 	input_abs_set_res(input, ABS_MT_POSITION_X, data->x_res);
1121 	input_abs_set_res(input, ABS_MT_POSITION_Y, data->y_res);
1122 	input_set_abs_params(input, ABS_MT_PRESSURE, 0,
1123 			     ETP_MAX_PRESSURE, 0, 0);
1124 	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
1125 			     ETP_FINGER_WIDTH * max_width, 0, 0);
1126 	input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0,
1127 			     ETP_FINGER_WIDTH * min_width, 0, 0);
1128 
1129 	data->input = input;
1130 
1131 	return 0;
1132 }
1133 
1134 static void elan_disable_regulator(void *_data)
1135 {
1136 	struct elan_tp_data *data = _data;
1137 
1138 	regulator_disable(data->vcc);
1139 }
1140 
1141 static void elan_remove_sysfs_groups(void *_data)
1142 {
1143 	struct elan_tp_data *data = _data;
1144 
1145 	sysfs_remove_groups(&data->client->dev.kobj, elan_sysfs_groups);
1146 }
1147 
1148 static int elan_probe(struct i2c_client *client,
1149 		      const struct i2c_device_id *dev_id)
1150 {
1151 	const struct elan_transport_ops *transport_ops;
1152 	struct device *dev = &client->dev;
1153 	struct elan_tp_data *data;
1154 	unsigned long irqflags;
1155 	int error;
1156 
1157 	if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_I2C) &&
1158 	    i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1159 		transport_ops = &elan_i2c_ops;
1160 	} else if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) &&
1161 		   i2c_check_functionality(client->adapter,
1162 					   I2C_FUNC_SMBUS_BYTE_DATA |
1163 						I2C_FUNC_SMBUS_BLOCK_DATA |
1164 						I2C_FUNC_SMBUS_I2C_BLOCK)) {
1165 		transport_ops = &elan_smbus_ops;
1166 	} else {
1167 		dev_err(dev, "not a supported I2C/SMBus adapter\n");
1168 		return -EIO;
1169 	}
1170 
1171 	data = devm_kzalloc(dev, sizeof(struct elan_tp_data), GFP_KERNEL);
1172 	if (!data)
1173 		return -ENOMEM;
1174 
1175 	i2c_set_clientdata(client, data);
1176 
1177 	data->ops = transport_ops;
1178 	data->client = client;
1179 	init_completion(&data->fw_completion);
1180 	mutex_init(&data->sysfs_mutex);
1181 
1182 	data->vcc = devm_regulator_get(dev, "vcc");
1183 	if (IS_ERR(data->vcc)) {
1184 		error = PTR_ERR(data->vcc);
1185 		if (error != -EPROBE_DEFER)
1186 			dev_err(dev, "Failed to get 'vcc' regulator: %d\n",
1187 				error);
1188 		return error;
1189 	}
1190 
1191 	error = regulator_enable(data->vcc);
1192 	if (error) {
1193 		dev_err(dev, "Failed to enable regulator: %d\n", error);
1194 		return error;
1195 	}
1196 
1197 	error = devm_add_action(dev, elan_disable_regulator, data);
1198 	if (error) {
1199 		regulator_disable(data->vcc);
1200 		dev_err(dev, "Failed to add disable regulator action: %d\n",
1201 			error);
1202 		return error;
1203 	}
1204 
1205 	/* Make sure there is something at this address */
1206 	error = i2c_smbus_read_byte(client);
1207 	if (error < 0) {
1208 		dev_dbg(&client->dev, "nothing at this address: %d\n", error);
1209 		return -ENXIO;
1210 	}
1211 
1212 	/* Initialize the touchpad. */
1213 	error = elan_initialize(data);
1214 	if (error)
1215 		return error;
1216 
1217 	error = elan_query_device_info(data);
1218 	if (error)
1219 		return error;
1220 
1221 	error = elan_query_device_parameters(data);
1222 	if (error)
1223 		return error;
1224 
1225 	dev_info(dev,
1226 		 "Elan Touchpad: Module ID: 0x%04x, Firmware: 0x%04x, Sample: 0x%04x, IAP: 0x%04x\n",
1227 		 data->product_id,
1228 		 data->fw_version,
1229 		 data->sm_version,
1230 		 data->iap_version);
1231 
1232 	dev_dbg(dev,
1233 		"Elan Touchpad Extra Information:\n"
1234 		"    Max ABS X,Y:   %d,%d\n"
1235 		"    Width X,Y:   %d,%d\n"
1236 		"    Resolution X,Y:   %d,%d (dots/mm)\n"
1237 		"    ic type: 0x%x\n"
1238 		"    info pattern: 0x%x\n",
1239 		data->max_x, data->max_y,
1240 		data->width_x, data->width_y,
1241 		data->x_res, data->y_res,
1242 		data->ic_type, data->pattern);
1243 
1244 	/* Set up input device properties based on queried parameters. */
1245 	error = elan_setup_input_device(data);
1246 	if (error)
1247 		return error;
1248 
1249 	if (device_property_read_bool(&client->dev, "elan,trackpoint")) {
1250 		error = elan_setup_trackpoint_input_device(data);
1251 		if (error)
1252 			return error;
1253 	}
1254 
1255 	/*
1256 	 * Platform code (ACPI, DTS) should normally set up interrupt
1257 	 * for us, but in case it did not let's fall back to using falling
1258 	 * edge to be compatible with older Chromebooks.
1259 	 */
1260 	irqflags = irq_get_trigger_type(client->irq);
1261 	if (!irqflags)
1262 		irqflags = IRQF_TRIGGER_FALLING;
1263 
1264 	error = devm_request_threaded_irq(dev, client->irq, NULL, elan_isr,
1265 					  irqflags | IRQF_ONESHOT,
1266 					  client->name, data);
1267 	if (error) {
1268 		dev_err(dev, "cannot register irq=%d\n", client->irq);
1269 		return error;
1270 	}
1271 
1272 	error = sysfs_create_groups(&dev->kobj, elan_sysfs_groups);
1273 	if (error) {
1274 		dev_err(dev, "failed to create sysfs attributes: %d\n", error);
1275 		return error;
1276 	}
1277 
1278 	error = devm_add_action(dev, elan_remove_sysfs_groups, data);
1279 	if (error) {
1280 		elan_remove_sysfs_groups(data);
1281 		dev_err(dev, "Failed to add sysfs cleanup action: %d\n",
1282 			error);
1283 		return error;
1284 	}
1285 
1286 	error = input_register_device(data->input);
1287 	if (error) {
1288 		dev_err(dev, "failed to register input device: %d\n", error);
1289 		return error;
1290 	}
1291 
1292 	if (data->tp_input) {
1293 		error = input_register_device(data->tp_input);
1294 		if (error) {
1295 			dev_err(&client->dev,
1296 				"failed to register TrackPoint input device: %d\n",
1297 				error);
1298 			return error;
1299 		}
1300 	}
1301 
1302 	/*
1303 	 * Systems using device tree should set up wakeup via DTS,
1304 	 * the rest will configure device as wakeup source by default.
1305 	 */
1306 	if (!dev->of_node)
1307 		device_init_wakeup(dev, true);
1308 
1309 	return 0;
1310 }
1311 
1312 static int __maybe_unused elan_suspend(struct device *dev)
1313 {
1314 	struct i2c_client *client = to_i2c_client(dev);
1315 	struct elan_tp_data *data = i2c_get_clientdata(client);
1316 	int ret;
1317 
1318 	/*
1319 	 * We are taking the mutex to make sure sysfs operations are
1320 	 * complete before we attempt to bring the device into low[er]
1321 	 * power mode.
1322 	 */
1323 	ret = mutex_lock_interruptible(&data->sysfs_mutex);
1324 	if (ret)
1325 		return ret;
1326 
1327 	disable_irq(client->irq);
1328 
1329 	if (device_may_wakeup(dev)) {
1330 		ret = elan_sleep(data);
1331 		/* Enable wake from IRQ */
1332 		data->irq_wake = (enable_irq_wake(client->irq) == 0);
1333 	} else {
1334 		ret = elan_disable_power(data);
1335 	}
1336 
1337 	mutex_unlock(&data->sysfs_mutex);
1338 	return ret;
1339 }
1340 
1341 static int __maybe_unused elan_resume(struct device *dev)
1342 {
1343 	struct i2c_client *client = to_i2c_client(dev);
1344 	struct elan_tp_data *data = i2c_get_clientdata(client);
1345 	int error;
1346 
1347 	if (device_may_wakeup(dev) && data->irq_wake) {
1348 		disable_irq_wake(client->irq);
1349 		data->irq_wake = false;
1350 	}
1351 
1352 	error = elan_enable_power(data);
1353 	if (error) {
1354 		dev_err(dev, "power up when resuming failed: %d\n", error);
1355 		goto err;
1356 	}
1357 
1358 	error = elan_initialize(data);
1359 	if (error)
1360 		dev_err(dev, "initialize when resuming failed: %d\n", error);
1361 
1362 err:
1363 	enable_irq(data->client->irq);
1364 	return error;
1365 }
1366 
1367 static SIMPLE_DEV_PM_OPS(elan_pm_ops, elan_suspend, elan_resume);
1368 
1369 static const struct i2c_device_id elan_id[] = {
1370 	{ DRIVER_NAME, 0 },
1371 	{ },
1372 };
1373 MODULE_DEVICE_TABLE(i2c, elan_id);
1374 
1375 #ifdef CONFIG_ACPI
1376 MODULE_DEVICE_TABLE(acpi, elan_acpi_id);
1377 #endif
1378 
1379 #ifdef CONFIG_OF
1380 static const struct of_device_id elan_of_match[] = {
1381 	{ .compatible = "elan,ekth3000" },
1382 	{ /* sentinel */ }
1383 };
1384 MODULE_DEVICE_TABLE(of, elan_of_match);
1385 #endif
1386 
1387 static struct i2c_driver elan_driver = {
1388 	.driver = {
1389 		.name	= DRIVER_NAME,
1390 		.pm	= &elan_pm_ops,
1391 		.acpi_match_table = ACPI_PTR(elan_acpi_id),
1392 		.of_match_table = of_match_ptr(elan_of_match),
1393 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1394 	},
1395 	.probe		= elan_probe,
1396 	.id_table	= elan_id,
1397 };
1398 
1399 module_i2c_driver(elan_driver);
1400 
1401 MODULE_AUTHOR("Duson Lin <dusonlin@emc.com.tw>");
1402 MODULE_DESCRIPTION("Elan I2C/SMBus Touchpad driver");
1403 MODULE_LICENSE("GPL");
1404