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: 1.6.2
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/module.h>
30 #include <linux/slab.h>
31 #include <linux/kernel.h>
32 #include <linux/sched.h>
33 #include <linux/input.h>
34 #include <linux/uaccess.h>
35 #include <linux/jiffies.h>
36 #include <linux/completion.h>
37 #include <linux/of.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_DRIVER_VERSION	"1.6.2"
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 	u16			product_id;
82 	u8			fw_version;
83 	u8			sm_version;
84 	u8			iap_version;
85 	u16			fw_checksum;
86 	int			pressure_adjustment;
87 	u8			mode;
88 	u8			ic_type;
89 	u16			fw_validpage_count;
90 	u16			fw_signature_address;
91 
92 	bool			irq_wake;
93 
94 	u8			min_baseline;
95 	u8			max_baseline;
96 	bool			baseline_ready;
97 };
98 
99 static int elan_get_fwinfo(u8 iap_version, u16 *validpage_count,
100 			   u16 *signature_address)
101 {
102 	switch (iap_version) {
103 	case 0x00:
104 	case 0x06:
105 	case 0x08:
106 		*validpage_count = 512;
107 		break;
108 	case 0x03:
109 	case 0x07:
110 	case 0x09:
111 	case 0x0A:
112 	case 0x0B:
113 	case 0x0C:
114 		*validpage_count = 768;
115 		break;
116 	case 0x0D:
117 		*validpage_count = 896;
118 		break;
119 	case 0x0E:
120 		*validpage_count = 640;
121 		break;
122 	default:
123 		/* unknown ic type clear value */
124 		*validpage_count = 0;
125 		*signature_address = 0;
126 		return -ENXIO;
127 	}
128 
129 	*signature_address =
130 		(*validpage_count * ETP_FW_PAGE_SIZE) - ETP_FW_SIGNATURE_SIZE;
131 
132 	return 0;
133 }
134 
135 static int elan_enable_power(struct elan_tp_data *data)
136 {
137 	int repeat = ETP_RETRY_COUNT;
138 	int error;
139 
140 	error = regulator_enable(data->vcc);
141 	if (error) {
142 		dev_err(&data->client->dev,
143 			"failed to enable regulator: %d\n", error);
144 		return error;
145 	}
146 
147 	do {
148 		error = data->ops->power_control(data->client, true);
149 		if (error >= 0)
150 			return 0;
151 
152 		msleep(30);
153 	} while (--repeat > 0);
154 
155 	dev_err(&data->client->dev, "failed to enable power: %d\n", error);
156 	return error;
157 }
158 
159 static int elan_disable_power(struct elan_tp_data *data)
160 {
161 	int repeat = ETP_RETRY_COUNT;
162 	int error;
163 
164 	do {
165 		error = data->ops->power_control(data->client, false);
166 		if (!error) {
167 			error = regulator_disable(data->vcc);
168 			if (error) {
169 				dev_err(&data->client->dev,
170 					"failed to disable regulator: %d\n",
171 					error);
172 				/* Attempt to power the chip back up */
173 				data->ops->power_control(data->client, true);
174 				break;
175 			}
176 
177 			return 0;
178 		}
179 
180 		msleep(30);
181 	} while (--repeat > 0);
182 
183 	dev_err(&data->client->dev, "failed to disable power: %d\n", error);
184 	return error;
185 }
186 
187 static int elan_sleep(struct elan_tp_data *data)
188 {
189 	int repeat = ETP_RETRY_COUNT;
190 	int error;
191 
192 	do {
193 		error = data->ops->sleep_control(data->client, true);
194 		if (!error)
195 			return 0;
196 
197 		msleep(30);
198 	} while (--repeat > 0);
199 
200 	return error;
201 }
202 
203 static int elan_query_product(struct elan_tp_data *data)
204 {
205 	int error;
206 
207 	error = data->ops->get_product_id(data->client, &data->product_id);
208 	if (error)
209 		return error;
210 
211 	error = data->ops->get_sm_version(data->client, &data->ic_type,
212 					  &data->sm_version);
213 	if (error)
214 		return error;
215 
216 	return 0;
217 }
218 
219 static int elan_check_ASUS_special_fw(struct elan_tp_data *data)
220 {
221 	if (data->ic_type != 0x0E)
222 		return false;
223 
224 	switch (data->product_id) {
225 	case 0x05 ... 0x07:
226 	case 0x09:
227 	case 0x13:
228 		return true;
229 	default:
230 		return false;
231 	}
232 }
233 
234 static int __elan_initialize(struct elan_tp_data *data)
235 {
236 	struct i2c_client *client = data->client;
237 	bool woken_up = false;
238 	int error;
239 
240 	error = data->ops->initialize(client);
241 	if (error) {
242 		dev_err(&client->dev, "device initialize failed: %d\n", error);
243 		return error;
244 	}
245 
246 	error = elan_query_product(data);
247 	if (error)
248 		return error;
249 
250 	/*
251 	 * Some ASUS devices were shipped with firmware that requires
252 	 * touchpads to be woken up first, before attempting to switch
253 	 * them into absolute reporting mode.
254 	 */
255 	if (elan_check_ASUS_special_fw(data)) {
256 		error = data->ops->sleep_control(client, false);
257 		if (error) {
258 			dev_err(&client->dev,
259 				"failed to wake device up: %d\n", error);
260 			return error;
261 		}
262 
263 		msleep(200);
264 		woken_up = true;
265 	}
266 
267 	data->mode |= ETP_ENABLE_ABS;
268 	error = data->ops->set_mode(client, data->mode);
269 	if (error) {
270 		dev_err(&client->dev,
271 			"failed to switch to absolute mode: %d\n", error);
272 		return error;
273 	}
274 
275 	if (!woken_up) {
276 		error = data->ops->sleep_control(client, false);
277 		if (error) {
278 			dev_err(&client->dev,
279 				"failed to wake device up: %d\n", error);
280 			return error;
281 		}
282 	}
283 
284 	return 0;
285 }
286 
287 static int elan_initialize(struct elan_tp_data *data)
288 {
289 	int repeat = ETP_RETRY_COUNT;
290 	int error;
291 
292 	do {
293 		error = __elan_initialize(data);
294 		if (!error)
295 			return 0;
296 
297 		msleep(30);
298 	} while (--repeat > 0);
299 
300 	return error;
301 }
302 
303 static int elan_query_device_info(struct elan_tp_data *data)
304 {
305 	int error;
306 
307 	error = data->ops->get_version(data->client, false, &data->fw_version);
308 	if (error)
309 		return error;
310 
311 	error = data->ops->get_checksum(data->client, false,
312 					&data->fw_checksum);
313 	if (error)
314 		return error;
315 
316 	error = data->ops->get_version(data->client, true, &data->iap_version);
317 	if (error)
318 		return error;
319 
320 	error = data->ops->get_pressure_adjustment(data->client,
321 						   &data->pressure_adjustment);
322 	if (error)
323 		return error;
324 
325 	error = elan_get_fwinfo(data->iap_version, &data->fw_validpage_count,
326 				&data->fw_signature_address);
327 	if (error)
328 		dev_warn(&data->client->dev,
329 			 "unexpected iap version %#04x (ic type: %#04x), firmware update will not work\n",
330 			 data->iap_version, data->ic_type);
331 
332 	return 0;
333 }
334 
335 static unsigned int elan_convert_resolution(u8 val)
336 {
337 	/*
338 	 * (value from firmware) * 10 + 790 = dpi
339 	 *
340 	 * We also have to convert dpi to dots/mm (*10/254 to avoid floating
341 	 * point).
342 	 */
343 
344 	return ((int)(char)val * 10 + 790) * 10 / 254;
345 }
346 
347 static int elan_query_device_parameters(struct elan_tp_data *data)
348 {
349 	unsigned int x_traces, y_traces;
350 	u8 hw_x_res, hw_y_res;
351 	int error;
352 
353 	error = data->ops->get_max(data->client, &data->max_x, &data->max_y);
354 	if (error)
355 		return error;
356 
357 	error = data->ops->get_num_traces(data->client, &x_traces, &y_traces);
358 	if (error)
359 		return error;
360 
361 	data->width_x = data->max_x / x_traces;
362 	data->width_y = data->max_y / y_traces;
363 
364 	error = data->ops->get_resolution(data->client, &hw_x_res, &hw_y_res);
365 	if (error)
366 		return error;
367 
368 	data->x_res = elan_convert_resolution(hw_x_res);
369 	data->y_res = elan_convert_resolution(hw_y_res);
370 
371 	return 0;
372 }
373 
374 /*
375  **********************************************************
376  * IAP firmware updater related routines
377  **********************************************************
378  */
379 static int elan_write_fw_block(struct elan_tp_data *data,
380 			       const u8 *page, u16 checksum, int idx)
381 {
382 	int retry = ETP_RETRY_COUNT;
383 	int error;
384 
385 	do {
386 		error = data->ops->write_fw_block(data->client,
387 						  page, checksum, idx);
388 		if (!error)
389 			return 0;
390 
391 		dev_dbg(&data->client->dev,
392 			"IAP retrying page %d (error: %d)\n", idx, error);
393 	} while (--retry > 0);
394 
395 	return error;
396 }
397 
398 static int __elan_update_firmware(struct elan_tp_data *data,
399 				  const struct firmware *fw)
400 {
401 	struct i2c_client *client = data->client;
402 	struct device *dev = &client->dev;
403 	int i, j;
404 	int error;
405 	u16 iap_start_addr;
406 	u16 boot_page_count;
407 	u16 sw_checksum = 0, fw_checksum = 0;
408 
409 	error = data->ops->prepare_fw_update(client);
410 	if (error)
411 		return error;
412 
413 	iap_start_addr = get_unaligned_le16(&fw->data[ETP_IAP_START_ADDR * 2]);
414 
415 	boot_page_count = (iap_start_addr * 2) / ETP_FW_PAGE_SIZE;
416 	for (i = boot_page_count; i < data->fw_validpage_count; i++) {
417 		u16 checksum = 0;
418 		const u8 *page = &fw->data[i * ETP_FW_PAGE_SIZE];
419 
420 		for (j = 0; j < ETP_FW_PAGE_SIZE; j += 2)
421 			checksum += ((page[j + 1] << 8) | page[j]);
422 
423 		error = elan_write_fw_block(data, page, checksum, i);
424 		if (error) {
425 			dev_err(dev, "write page %d fail: %d\n", i, error);
426 			return error;
427 		}
428 
429 		sw_checksum += checksum;
430 	}
431 
432 	/* Wait WDT reset and power on reset */
433 	msleep(600);
434 
435 	error = data->ops->finish_fw_update(client, &data->fw_completion);
436 	if (error)
437 		return error;
438 
439 	error = data->ops->get_checksum(client, true, &fw_checksum);
440 	if (error)
441 		return error;
442 
443 	if (sw_checksum != fw_checksum) {
444 		dev_err(dev, "checksum diff sw=[%04X], fw=[%04X]\n",
445 			sw_checksum, fw_checksum);
446 		return -EIO;
447 	}
448 
449 	return 0;
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 	int retval;
457 
458 	dev_dbg(&client->dev, "Starting firmware update....\n");
459 
460 	disable_irq(client->irq);
461 	data->in_fw_update = true;
462 
463 	retval = __elan_update_firmware(data, fw);
464 	if (retval) {
465 		dev_err(&client->dev, "firmware update failed: %d\n", retval);
466 		data->ops->iap_reset(client);
467 	} else {
468 		/* Reinitialize TP after fw is updated */
469 		elan_initialize(data);
470 		elan_query_device_info(data);
471 	}
472 
473 	data->in_fw_update = false;
474 	enable_irq(client->irq);
475 
476 	return retval;
477 }
478 
479 /*
480  *******************************************************************
481  * SYSFS attributes
482  *******************************************************************
483  */
484 static ssize_t elan_sysfs_read_fw_checksum(struct device *dev,
485 					   struct device_attribute *attr,
486 					   char *buf)
487 {
488 	struct i2c_client *client = to_i2c_client(dev);
489 	struct elan_tp_data *data = i2c_get_clientdata(client);
490 
491 	return sprintf(buf, "0x%04x\n", data->fw_checksum);
492 }
493 
494 static ssize_t elan_sysfs_read_product_id(struct device *dev,
495 					 struct device_attribute *attr,
496 					 char *buf)
497 {
498 	struct i2c_client *client = to_i2c_client(dev);
499 	struct elan_tp_data *data = i2c_get_clientdata(client);
500 
501 	return sprintf(buf, ETP_PRODUCT_ID_FORMAT_STRING "\n",
502 		       data->product_id);
503 }
504 
505 static ssize_t elan_sysfs_read_fw_ver(struct device *dev,
506 				      struct device_attribute *attr,
507 				      char *buf)
508 {
509 	struct i2c_client *client = to_i2c_client(dev);
510 	struct elan_tp_data *data = i2c_get_clientdata(client);
511 
512 	return sprintf(buf, "%d.0\n", data->fw_version);
513 }
514 
515 static ssize_t elan_sysfs_read_sm_ver(struct device *dev,
516 				      struct device_attribute *attr,
517 				      char *buf)
518 {
519 	struct i2c_client *client = to_i2c_client(dev);
520 	struct elan_tp_data *data = i2c_get_clientdata(client);
521 
522 	return sprintf(buf, "%d.0\n", data->sm_version);
523 }
524 
525 static ssize_t elan_sysfs_read_iap_ver(struct device *dev,
526 				       struct device_attribute *attr,
527 				       char *buf)
528 {
529 	struct i2c_client *client = to_i2c_client(dev);
530 	struct elan_tp_data *data = i2c_get_clientdata(client);
531 
532 	return sprintf(buf, "%d.0\n", data->iap_version);
533 }
534 
535 static ssize_t elan_sysfs_update_fw(struct device *dev,
536 				    struct device_attribute *attr,
537 				    const char *buf, size_t count)
538 {
539 	struct elan_tp_data *data = dev_get_drvdata(dev);
540 	const struct firmware *fw;
541 	char *fw_name;
542 	int error;
543 	const u8 *fw_signature;
544 	static const u8 signature[] = {0xAA, 0x55, 0xCC, 0x33, 0xFF, 0xFF};
545 
546 	if (data->fw_validpage_count == 0)
547 		return -EINVAL;
548 
549 	/* Look for a firmware with the product id appended. */
550 	fw_name = kasprintf(GFP_KERNEL, ETP_FW_NAME, data->product_id);
551 	if (!fw_name) {
552 		dev_err(dev, "failed to allocate memory for firmware name\n");
553 		return -ENOMEM;
554 	}
555 
556 	dev_info(dev, "requesting fw '%s'\n", fw_name);
557 	error = request_firmware(&fw, fw_name, dev);
558 	kfree(fw_name);
559 	if (error) {
560 		dev_err(dev, "failed to request firmware: %d\n", error);
561 		return error;
562 	}
563 
564 	/* Firmware file must match signature data */
565 	fw_signature = &fw->data[data->fw_signature_address];
566 	if (memcmp(fw_signature, signature, sizeof(signature)) != 0) {
567 		dev_err(dev, "signature mismatch (expected %*ph, got %*ph)\n",
568 			(int)sizeof(signature), signature,
569 			(int)sizeof(signature), fw_signature);
570 		error = -EBADF;
571 		goto out_release_fw;
572 	}
573 
574 	error = mutex_lock_interruptible(&data->sysfs_mutex);
575 	if (error)
576 		goto out_release_fw;
577 
578 	error = elan_update_firmware(data, fw);
579 
580 	mutex_unlock(&data->sysfs_mutex);
581 
582 out_release_fw:
583 	release_firmware(fw);
584 	return error ?: count;
585 }
586 
587 static ssize_t calibrate_store(struct device *dev,
588 			       struct device_attribute *attr,
589 			       const char *buf, size_t count)
590 {
591 	struct i2c_client *client = to_i2c_client(dev);
592 	struct elan_tp_data *data = i2c_get_clientdata(client);
593 	int tries = 20;
594 	int retval;
595 	int error;
596 	u8 val[3];
597 
598 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
599 	if (retval)
600 		return retval;
601 
602 	disable_irq(client->irq);
603 
604 	data->mode |= ETP_ENABLE_CALIBRATE;
605 	retval = data->ops->set_mode(client, data->mode);
606 	if (retval) {
607 		dev_err(dev, "failed to enable calibration mode: %d\n",
608 			retval);
609 		goto out;
610 	}
611 
612 	retval = data->ops->calibrate(client);
613 	if (retval) {
614 		dev_err(dev, "failed to start calibration: %d\n",
615 			retval);
616 		goto out_disable_calibrate;
617 	}
618 
619 	val[0] = 0xff;
620 	do {
621 		/* Wait 250ms before checking if calibration has completed. */
622 		msleep(250);
623 
624 		retval = data->ops->calibrate_result(client, val);
625 		if (retval)
626 			dev_err(dev, "failed to check calibration result: %d\n",
627 				retval);
628 		else if (val[0] == 0)
629 			break; /* calibration done */
630 
631 	} while (--tries);
632 
633 	if (tries == 0) {
634 		dev_err(dev, "failed to calibrate. Timeout.\n");
635 		retval = -ETIMEDOUT;
636 	}
637 
638 out_disable_calibrate:
639 	data->mode &= ~ETP_ENABLE_CALIBRATE;
640 	error = data->ops->set_mode(data->client, data->mode);
641 	if (error) {
642 		dev_err(dev, "failed to disable calibration mode: %d\n",
643 			error);
644 		if (!retval)
645 			retval = error;
646 	}
647 out:
648 	enable_irq(client->irq);
649 	mutex_unlock(&data->sysfs_mutex);
650 	return retval ?: count;
651 }
652 
653 static ssize_t elan_sysfs_read_mode(struct device *dev,
654 				    struct device_attribute *attr,
655 				    char *buf)
656 {
657 	struct i2c_client *client = to_i2c_client(dev);
658 	struct elan_tp_data *data = i2c_get_clientdata(client);
659 	int error;
660 	enum tp_mode mode;
661 
662 	error = mutex_lock_interruptible(&data->sysfs_mutex);
663 	if (error)
664 		return error;
665 
666 	error = data->ops->iap_get_mode(data->client, &mode);
667 
668 	mutex_unlock(&data->sysfs_mutex);
669 
670 	if (error)
671 		return error;
672 
673 	return sprintf(buf, "%d\n", (int)mode);
674 }
675 
676 static DEVICE_ATTR(product_id, S_IRUGO, elan_sysfs_read_product_id, NULL);
677 static DEVICE_ATTR(firmware_version, S_IRUGO, elan_sysfs_read_fw_ver, NULL);
678 static DEVICE_ATTR(sample_version, S_IRUGO, elan_sysfs_read_sm_ver, NULL);
679 static DEVICE_ATTR(iap_version, S_IRUGO, elan_sysfs_read_iap_ver, NULL);
680 static DEVICE_ATTR(fw_checksum, S_IRUGO, elan_sysfs_read_fw_checksum, NULL);
681 static DEVICE_ATTR(mode, S_IRUGO, elan_sysfs_read_mode, NULL);
682 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, elan_sysfs_update_fw);
683 
684 static DEVICE_ATTR_WO(calibrate);
685 
686 static struct attribute *elan_sysfs_entries[] = {
687 	&dev_attr_product_id.attr,
688 	&dev_attr_firmware_version.attr,
689 	&dev_attr_sample_version.attr,
690 	&dev_attr_iap_version.attr,
691 	&dev_attr_fw_checksum.attr,
692 	&dev_attr_calibrate.attr,
693 	&dev_attr_mode.attr,
694 	&dev_attr_update_fw.attr,
695 	NULL,
696 };
697 
698 static const struct attribute_group elan_sysfs_group = {
699 	.attrs = elan_sysfs_entries,
700 };
701 
702 static ssize_t acquire_store(struct device *dev, struct device_attribute *attr,
703 			     const char *buf, size_t count)
704 {
705 	struct i2c_client *client = to_i2c_client(dev);
706 	struct elan_tp_data *data = i2c_get_clientdata(client);
707 	int error;
708 	int retval;
709 
710 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
711 	if (retval)
712 		return retval;
713 
714 	disable_irq(client->irq);
715 
716 	data->baseline_ready = false;
717 
718 	data->mode |= ETP_ENABLE_CALIBRATE;
719 	retval = data->ops->set_mode(data->client, data->mode);
720 	if (retval) {
721 		dev_err(dev, "Failed to enable calibration mode to get baseline: %d\n",
722 			retval);
723 		goto out;
724 	}
725 
726 	msleep(250);
727 
728 	retval = data->ops->get_baseline_data(data->client, true,
729 					      &data->max_baseline);
730 	if (retval) {
731 		dev_err(dev, "Failed to read max baseline form device: %d\n",
732 			retval);
733 		goto out_disable_calibrate;
734 	}
735 
736 	retval = data->ops->get_baseline_data(data->client, false,
737 					      &data->min_baseline);
738 	if (retval) {
739 		dev_err(dev, "Failed to read min baseline form device: %d\n",
740 			retval);
741 		goto out_disable_calibrate;
742 	}
743 
744 	data->baseline_ready = true;
745 
746 out_disable_calibrate:
747 	data->mode &= ~ETP_ENABLE_CALIBRATE;
748 	error = data->ops->set_mode(data->client, data->mode);
749 	if (error) {
750 		dev_err(dev, "Failed to disable calibration mode after acquiring baseline: %d\n",
751 			error);
752 		if (!retval)
753 			retval = error;
754 	}
755 out:
756 	enable_irq(client->irq);
757 	mutex_unlock(&data->sysfs_mutex);
758 	return retval ?: count;
759 }
760 
761 static ssize_t min_show(struct device *dev,
762 			struct device_attribute *attr, char *buf)
763 {
764 	struct i2c_client *client = to_i2c_client(dev);
765 	struct elan_tp_data *data = i2c_get_clientdata(client);
766 	int retval;
767 
768 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
769 	if (retval)
770 		return retval;
771 
772 	if (!data->baseline_ready) {
773 		retval = -ENODATA;
774 		goto out;
775 	}
776 
777 	retval = snprintf(buf, PAGE_SIZE, "%d", data->min_baseline);
778 
779 out:
780 	mutex_unlock(&data->sysfs_mutex);
781 	return retval;
782 }
783 
784 static ssize_t max_show(struct device *dev,
785 			struct device_attribute *attr, char *buf)
786 {
787 	struct i2c_client *client = to_i2c_client(dev);
788 	struct elan_tp_data *data = i2c_get_clientdata(client);
789 	int retval;
790 
791 	retval = mutex_lock_interruptible(&data->sysfs_mutex);
792 	if (retval)
793 		return retval;
794 
795 	if (!data->baseline_ready) {
796 		retval = -ENODATA;
797 		goto out;
798 	}
799 
800 	retval = snprintf(buf, PAGE_SIZE, "%d", data->max_baseline);
801 
802 out:
803 	mutex_unlock(&data->sysfs_mutex);
804 	return retval;
805 }
806 
807 
808 static DEVICE_ATTR_WO(acquire);
809 static DEVICE_ATTR_RO(min);
810 static DEVICE_ATTR_RO(max);
811 
812 static struct attribute *elan_baseline_sysfs_entries[] = {
813 	&dev_attr_acquire.attr,
814 	&dev_attr_min.attr,
815 	&dev_attr_max.attr,
816 	NULL,
817 };
818 
819 static const struct attribute_group elan_baseline_sysfs_group = {
820 	.name = "baseline",
821 	.attrs = elan_baseline_sysfs_entries,
822 };
823 
824 static const struct attribute_group *elan_sysfs_groups[] = {
825 	&elan_sysfs_group,
826 	&elan_baseline_sysfs_group,
827 	NULL
828 };
829 
830 /*
831  ******************************************************************
832  * Elan isr functions
833  ******************************************************************
834  */
835 static void elan_report_contact(struct elan_tp_data *data,
836 				int contact_num, bool contact_valid,
837 				u8 *finger_data)
838 {
839 	struct input_dev *input = data->input;
840 	unsigned int pos_x, pos_y;
841 	unsigned int pressure, mk_x, mk_y;
842 	unsigned int area_x, area_y, major, minor;
843 	unsigned int scaled_pressure;
844 
845 	if (contact_valid) {
846 		pos_x = ((finger_data[0] & 0xf0) << 4) |
847 						finger_data[1];
848 		pos_y = ((finger_data[0] & 0x0f) << 8) |
849 						finger_data[2];
850 		mk_x = (finger_data[3] & 0x0f);
851 		mk_y = (finger_data[3] >> 4);
852 		pressure = finger_data[4];
853 
854 		if (pos_x > data->max_x || pos_y > data->max_y) {
855 			dev_dbg(input->dev.parent,
856 				"[%d] x=%d y=%d over max (%d, %d)",
857 				contact_num, pos_x, pos_y,
858 				data->max_x, data->max_y);
859 			return;
860 		}
861 
862 		/*
863 		 * To avoid treating large finger as palm, let's reduce the
864 		 * width x and y per trace.
865 		 */
866 		area_x = mk_x * (data->width_x - ETP_FWIDTH_REDUCE);
867 		area_y = mk_y * (data->width_y - ETP_FWIDTH_REDUCE);
868 
869 		major = max(area_x, area_y);
870 		minor = min(area_x, area_y);
871 
872 		scaled_pressure = pressure + data->pressure_adjustment;
873 
874 		if (scaled_pressure > ETP_MAX_PRESSURE)
875 			scaled_pressure = ETP_MAX_PRESSURE;
876 
877 		input_mt_slot(input, contact_num);
878 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
879 		input_report_abs(input, ABS_MT_POSITION_X, pos_x);
880 		input_report_abs(input, ABS_MT_POSITION_Y, data->max_y - pos_y);
881 		input_report_abs(input, ABS_MT_PRESSURE, scaled_pressure);
882 		input_report_abs(input, ABS_TOOL_WIDTH, mk_x);
883 		input_report_abs(input, ABS_MT_TOUCH_MAJOR, major);
884 		input_report_abs(input, ABS_MT_TOUCH_MINOR, minor);
885 	} else {
886 		input_mt_slot(input, contact_num);
887 		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
888 	}
889 }
890 
891 static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
892 {
893 	struct input_dev *input = data->input;
894 	u8 *finger_data = &packet[ETP_FINGER_DATA_OFFSET];
895 	int i;
896 	u8 tp_info = packet[ETP_TOUCH_INFO_OFFSET];
897 	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
898 	bool contact_valid, hover_event;
899 
900 	hover_event = hover_info & 0x40;
901 	for (i = 0; i < ETP_MAX_FINGERS; i++) {
902 		contact_valid = tp_info & (1U << (3 + i));
903 		elan_report_contact(data, i, contact_valid, finger_data);
904 
905 		if (contact_valid)
906 			finger_data += ETP_FINGER_DATA_LEN;
907 	}
908 
909 	input_report_key(input, BTN_LEFT, tp_info & 0x01);
910 	input_report_abs(input, ABS_DISTANCE, hover_event != 0);
911 	input_mt_report_pointer_emulation(input, true);
912 	input_sync(input);
913 }
914 
915 static irqreturn_t elan_isr(int irq, void *dev_id)
916 {
917 	struct elan_tp_data *data = dev_id;
918 	struct device *dev = &data->client->dev;
919 	int error;
920 	u8 report[ETP_MAX_REPORT_LEN];
921 
922 	/*
923 	 * When device is connected to i2c bus, when all IAP page writes
924 	 * complete, the driver will receive interrupt and must read
925 	 * 0000 to confirm that IAP is finished.
926 	*/
927 	if (data->in_fw_update) {
928 		complete(&data->fw_completion);
929 		goto out;
930 	}
931 
932 	error = data->ops->get_report(data->client, report);
933 	if (error)
934 		goto out;
935 
936 	if (report[ETP_REPORT_ID_OFFSET] != ETP_REPORT_ID)
937 		dev_err(dev, "invalid report id data (%x)\n",
938 			report[ETP_REPORT_ID_OFFSET]);
939 	else
940 		elan_report_absolute(data, report);
941 
942 out:
943 	return IRQ_HANDLED;
944 }
945 
946 /*
947  ******************************************************************
948  * Elan initialization functions
949  ******************************************************************
950  */
951 static int elan_setup_input_device(struct elan_tp_data *data)
952 {
953 	struct device *dev = &data->client->dev;
954 	struct input_dev *input;
955 	unsigned int max_width = max(data->width_x, data->width_y);
956 	unsigned int min_width = min(data->width_x, data->width_y);
957 	int error;
958 
959 	input = devm_input_allocate_device(dev);
960 	if (!input)
961 		return -ENOMEM;
962 
963 	input->name = "Elan Touchpad";
964 	input->id.bustype = BUS_I2C;
965 	input->id.vendor = ELAN_VENDOR_ID;
966 	input->id.product = data->product_id;
967 	input_set_drvdata(input, data);
968 
969 	error = input_mt_init_slots(input, ETP_MAX_FINGERS,
970 				    INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED);
971 	if (error) {
972 		dev_err(dev, "failed to initialize MT slots: %d\n", error);
973 		return error;
974 	}
975 
976 	__set_bit(EV_ABS, input->evbit);
977 	__set_bit(INPUT_PROP_POINTER, input->propbit);
978 	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
979 	__set_bit(BTN_LEFT, input->keybit);
980 
981 	/* Set up ST parameters */
982 	input_set_abs_params(input, ABS_X, 0, data->max_x, 0, 0);
983 	input_set_abs_params(input, ABS_Y, 0, data->max_y, 0, 0);
984 	input_abs_set_res(input, ABS_X, data->x_res);
985 	input_abs_set_res(input, ABS_Y, data->y_res);
986 	input_set_abs_params(input, ABS_PRESSURE, 0, ETP_MAX_PRESSURE, 0, 0);
987 	input_set_abs_params(input, ABS_TOOL_WIDTH, 0, ETP_FINGER_WIDTH, 0, 0);
988 	input_set_abs_params(input, ABS_DISTANCE, 0, 1, 0, 0);
989 
990 	/* And MT parameters */
991 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, data->max_x, 0, 0);
992 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, data->max_y, 0, 0);
993 	input_abs_set_res(input, ABS_MT_POSITION_X, data->x_res);
994 	input_abs_set_res(input, ABS_MT_POSITION_Y, data->y_res);
995 	input_set_abs_params(input, ABS_MT_PRESSURE, 0,
996 			     ETP_MAX_PRESSURE, 0, 0);
997 	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0,
998 			     ETP_FINGER_WIDTH * max_width, 0, 0);
999 	input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0,
1000 			     ETP_FINGER_WIDTH * min_width, 0, 0);
1001 
1002 	data->input = input;
1003 
1004 	return 0;
1005 }
1006 
1007 static void elan_disable_regulator(void *_data)
1008 {
1009 	struct elan_tp_data *data = _data;
1010 
1011 	regulator_disable(data->vcc);
1012 }
1013 
1014 static void elan_remove_sysfs_groups(void *_data)
1015 {
1016 	struct elan_tp_data *data = _data;
1017 
1018 	sysfs_remove_groups(&data->client->dev.kobj, elan_sysfs_groups);
1019 }
1020 
1021 static int elan_probe(struct i2c_client *client,
1022 		      const struct i2c_device_id *dev_id)
1023 {
1024 	const struct elan_transport_ops *transport_ops;
1025 	struct device *dev = &client->dev;
1026 	struct elan_tp_data *data;
1027 	unsigned long irqflags;
1028 	int error;
1029 
1030 	if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_I2C) &&
1031 	    i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1032 		transport_ops = &elan_i2c_ops;
1033 	} else if (IS_ENABLED(CONFIG_MOUSE_ELAN_I2C_SMBUS) &&
1034 		   i2c_check_functionality(client->adapter,
1035 					   I2C_FUNC_SMBUS_BYTE_DATA |
1036 						I2C_FUNC_SMBUS_BLOCK_DATA |
1037 						I2C_FUNC_SMBUS_I2C_BLOCK)) {
1038 		transport_ops = &elan_smbus_ops;
1039 	} else {
1040 		dev_err(dev, "not a supported I2C/SMBus adapter\n");
1041 		return -EIO;
1042 	}
1043 
1044 	data = devm_kzalloc(dev, sizeof(struct elan_tp_data), GFP_KERNEL);
1045 	if (!data)
1046 		return -ENOMEM;
1047 
1048 	i2c_set_clientdata(client, data);
1049 
1050 	data->ops = transport_ops;
1051 	data->client = client;
1052 	init_completion(&data->fw_completion);
1053 	mutex_init(&data->sysfs_mutex);
1054 
1055 	data->vcc = devm_regulator_get(dev, "vcc");
1056 	if (IS_ERR(data->vcc)) {
1057 		error = PTR_ERR(data->vcc);
1058 		if (error != -EPROBE_DEFER)
1059 			dev_err(dev, "Failed to get 'vcc' regulator: %d\n",
1060 				error);
1061 		return error;
1062 	}
1063 
1064 	error = regulator_enable(data->vcc);
1065 	if (error) {
1066 		dev_err(dev, "Failed to enable regulator: %d\n", error);
1067 		return error;
1068 	}
1069 
1070 	error = devm_add_action(dev, elan_disable_regulator, data);
1071 	if (error) {
1072 		regulator_disable(data->vcc);
1073 		dev_err(dev, "Failed to add disable regulator action: %d\n",
1074 			error);
1075 		return error;
1076 	}
1077 
1078 	/* Initialize the touchpad. */
1079 	error = elan_initialize(data);
1080 	if (error)
1081 		return error;
1082 
1083 	error = elan_query_device_info(data);
1084 	if (error)
1085 		return error;
1086 
1087 	error = elan_query_device_parameters(data);
1088 	if (error)
1089 		return error;
1090 
1091 	dev_info(dev,
1092 		 "Elan Touchpad: Module ID: 0x%04x, Firmware: 0x%04x, Sample: 0x%04x, IAP: 0x%04x\n",
1093 		 data->product_id,
1094 		 data->fw_version,
1095 		 data->sm_version,
1096 		 data->iap_version);
1097 
1098 	dev_dbg(dev,
1099 		"Elan Touchpad Extra Information:\n"
1100 		"    Max ABS X,Y:   %d,%d\n"
1101 		"    Width X,Y:   %d,%d\n"
1102 		"    Resolution X,Y:   %d,%d (dots/mm)\n",
1103 		data->max_x, data->max_y,
1104 		data->width_x, data->width_y,
1105 		data->x_res, data->y_res);
1106 
1107 	/* Set up input device properties based on queried parameters. */
1108 	error = elan_setup_input_device(data);
1109 	if (error)
1110 		return error;
1111 
1112 	/*
1113 	 * Systems using device tree should set up interrupt via DTS,
1114 	 * the rest will use the default falling edge interrupts.
1115 	 */
1116 	irqflags = dev->of_node ? 0 : IRQF_TRIGGER_FALLING;
1117 
1118 	error = devm_request_threaded_irq(dev, client->irq, NULL, elan_isr,
1119 					  irqflags | IRQF_ONESHOT,
1120 					  client->name, data);
1121 	if (error) {
1122 		dev_err(dev, "cannot register irq=%d\n", client->irq);
1123 		return error;
1124 	}
1125 
1126 	error = sysfs_create_groups(&dev->kobj, elan_sysfs_groups);
1127 	if (error) {
1128 		dev_err(dev, "failed to create sysfs attributes: %d\n", error);
1129 		return error;
1130 	}
1131 
1132 	error = devm_add_action(dev, elan_remove_sysfs_groups, data);
1133 	if (error) {
1134 		elan_remove_sysfs_groups(data);
1135 		dev_err(dev, "Failed to add sysfs cleanup action: %d\n",
1136 			error);
1137 		return error;
1138 	}
1139 
1140 	error = input_register_device(data->input);
1141 	if (error) {
1142 		dev_err(dev, "failed to register input device: %d\n", error);
1143 		return error;
1144 	}
1145 
1146 	/*
1147 	 * Systems using device tree should set up wakeup via DTS,
1148 	 * the rest will configure device as wakeup source by default.
1149 	 */
1150 	if (!dev->of_node)
1151 		device_init_wakeup(dev, true);
1152 
1153 	return 0;
1154 }
1155 
1156 static int __maybe_unused elan_suspend(struct device *dev)
1157 {
1158 	struct i2c_client *client = to_i2c_client(dev);
1159 	struct elan_tp_data *data = i2c_get_clientdata(client);
1160 	int ret;
1161 
1162 	/*
1163 	 * We are taking the mutex to make sure sysfs operations are
1164 	 * complete before we attempt to bring the device into low[er]
1165 	 * power mode.
1166 	 */
1167 	ret = mutex_lock_interruptible(&data->sysfs_mutex);
1168 	if (ret)
1169 		return ret;
1170 
1171 	disable_irq(client->irq);
1172 
1173 	if (device_may_wakeup(dev)) {
1174 		ret = elan_sleep(data);
1175 		/* Enable wake from IRQ */
1176 		data->irq_wake = (enable_irq_wake(client->irq) == 0);
1177 	} else {
1178 		ret = elan_disable_power(data);
1179 	}
1180 
1181 	mutex_unlock(&data->sysfs_mutex);
1182 	return ret;
1183 }
1184 
1185 static int __maybe_unused elan_resume(struct device *dev)
1186 {
1187 	struct i2c_client *client = to_i2c_client(dev);
1188 	struct elan_tp_data *data = i2c_get_clientdata(client);
1189 	int error;
1190 
1191 	if (device_may_wakeup(dev) && data->irq_wake) {
1192 		disable_irq_wake(client->irq);
1193 		data->irq_wake = false;
1194 	}
1195 
1196 	error = elan_enable_power(data);
1197 	if (error) {
1198 		dev_err(dev, "power up when resuming failed: %d\n", error);
1199 		goto err;
1200 	}
1201 
1202 	error = elan_initialize(data);
1203 	if (error)
1204 		dev_err(dev, "initialize when resuming failed: %d\n", error);
1205 
1206 err:
1207 	enable_irq(data->client->irq);
1208 	return error;
1209 }
1210 
1211 static SIMPLE_DEV_PM_OPS(elan_pm_ops, elan_suspend, elan_resume);
1212 
1213 static const struct i2c_device_id elan_id[] = {
1214 	{ DRIVER_NAME, 0 },
1215 	{ },
1216 };
1217 MODULE_DEVICE_TABLE(i2c, elan_id);
1218 
1219 #ifdef CONFIG_ACPI
1220 static const struct acpi_device_id elan_acpi_id[] = {
1221 	{ "ELAN0000", 0 },
1222 	{ "ELAN0100", 0 },
1223 	{ "ELAN0600", 0 },
1224 	{ "ELAN0605", 0 },
1225 	{ "ELAN1000", 0 },
1226 	{ }
1227 };
1228 MODULE_DEVICE_TABLE(acpi, elan_acpi_id);
1229 #endif
1230 
1231 #ifdef CONFIG_OF
1232 static const struct of_device_id elan_of_match[] = {
1233 	{ .compatible = "elan,ekth3000" },
1234 	{ /* sentinel */ }
1235 };
1236 MODULE_DEVICE_TABLE(of, elan_of_match);
1237 #endif
1238 
1239 static struct i2c_driver elan_driver = {
1240 	.driver = {
1241 		.name	= DRIVER_NAME,
1242 		.pm	= &elan_pm_ops,
1243 		.acpi_match_table = ACPI_PTR(elan_acpi_id),
1244 		.of_match_table = of_match_ptr(elan_of_match),
1245 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1246 	},
1247 	.probe		= elan_probe,
1248 	.id_table	= elan_id,
1249 };
1250 
1251 module_i2c_driver(elan_driver);
1252 
1253 MODULE_AUTHOR("Duson Lin <dusonlin@emc.com.tw>");
1254 MODULE_DESCRIPTION("Elan I2C/SMBus Touchpad driver");
1255 MODULE_LICENSE("GPL");
1256 MODULE_VERSION(ELAN_DRIVER_VERSION);
1257