1 /*
2  * Elan Microelectronics touch panels with I2C interface
3  *
4  * Copyright (C) 2014 Elan Microelectronics Corporation.
5  * Scott Liu <scott.liu@emc.com.tw>
6  *
7  * This code is partly based on hid-multitouch.c:
8  *
9  *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
10  *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
11  *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
12  *
13  *
14  * This code is partly based on i2c-hid.c:
15  *
16  * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
17  * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
18  * Copyright (c) 2012 Red Hat, Inc
19  */
20 
21 /*
22  * This software is licensed under the terms of the GNU General Public
23  * License version 2, as published by the Free Software Foundation, and
24  * may be copied, distributed, and modified under those terms.
25  */
26 
27 #include <linux/module.h>
28 #include <linux/input.h>
29 #include <linux/interrupt.h>
30 #include <linux/irq.h>
31 #include <linux/platform_device.h>
32 #include <linux/async.h>
33 #include <linux/i2c.h>
34 #include <linux/delay.h>
35 #include <linux/uaccess.h>
36 #include <linux/buffer_head.h>
37 #include <linux/slab.h>
38 #include <linux/firmware.h>
39 #include <linux/input/mt.h>
40 #include <linux/acpi.h>
41 #include <linux/of.h>
42 #include <linux/gpio/consumer.h>
43 #include <linux/regulator/consumer.h>
44 #include <asm/unaligned.h>
45 
46 /* Device, Driver information */
47 #define DEVICE_NAME	"elants_i2c"
48 
49 /* Convert from rows or columns into resolution */
50 #define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
51 
52 /* FW header data */
53 #define HEADER_SIZE		4
54 #define FW_HDR_TYPE		0
55 #define FW_HDR_COUNT		1
56 #define FW_HDR_LENGTH		2
57 
58 /* Buffer mode Queue Header information */
59 #define QUEUE_HEADER_SINGLE	0x62
60 #define QUEUE_HEADER_NORMAL	0X63
61 #define QUEUE_HEADER_WAIT	0x64
62 
63 /* Command header definition */
64 #define CMD_HEADER_WRITE	0x54
65 #define CMD_HEADER_READ		0x53
66 #define CMD_HEADER_6B_READ	0x5B
67 #define CMD_HEADER_RESP		0x52
68 #define CMD_HEADER_6B_RESP	0x9B
69 #define CMD_HEADER_HELLO	0x55
70 #define CMD_HEADER_REK		0x66
71 
72 /* FW position data */
73 #define PACKET_SIZE		55
74 #define MAX_CONTACT_NUM		10
75 #define FW_POS_HEADER		0
76 #define FW_POS_STATE		1
77 #define FW_POS_TOTAL		2
78 #define FW_POS_XY		3
79 #define FW_POS_CHECKSUM		34
80 #define FW_POS_WIDTH		35
81 #define FW_POS_PRESSURE		45
82 
83 #define HEADER_REPORT_10_FINGER	0x62
84 
85 /* Header (4 bytes) plus 3 fill 10-finger packets */
86 #define MAX_PACKET_SIZE		169
87 
88 #define BOOT_TIME_DELAY_MS	50
89 
90 /* FW read command, 0x53 0x?? 0x0, 0x01 */
91 #define E_ELAN_INFO_FW_VER	0x00
92 #define E_ELAN_INFO_BC_VER	0x10
93 #define E_ELAN_INFO_TEST_VER	0xE0
94 #define E_ELAN_INFO_FW_ID	0xF0
95 #define E_INFO_OSR		0xD6
96 #define E_INFO_PHY_SCAN		0xD7
97 #define E_INFO_PHY_DRIVER	0xD8
98 
99 #define MAX_RETRIES		3
100 #define MAX_FW_UPDATE_RETRIES	30
101 
102 #define ELAN_FW_PAGESIZE	132
103 
104 /* calibration timeout definition */
105 #define ELAN_CALI_TIMEOUT_MSEC	12000
106 
107 #define ELAN_POWERON_DELAY_USEC	500
108 #define ELAN_RESET_DELAY_MSEC	20
109 
110 enum elants_state {
111 	ELAN_STATE_NORMAL,
112 	ELAN_WAIT_QUEUE_HEADER,
113 	ELAN_WAIT_RECALIBRATION,
114 };
115 
116 enum elants_iap_mode {
117 	ELAN_IAP_OPERATIONAL,
118 	ELAN_IAP_RECOVERY,
119 };
120 
121 /* struct elants_data - represents state of Elan touchscreen device */
122 struct elants_data {
123 	struct i2c_client *client;
124 	struct input_dev *input;
125 
126 	struct regulator *vcc33;
127 	struct regulator *vccio;
128 	struct gpio_desc *reset_gpio;
129 
130 	u16 fw_version;
131 	u8 test_version;
132 	u8 solution_version;
133 	u8 bc_version;
134 	u8 iap_version;
135 	u16 hw_version;
136 	unsigned int x_res;	/* resolution in units/mm */
137 	unsigned int y_res;
138 	unsigned int x_max;
139 	unsigned int y_max;
140 
141 	enum elants_state state;
142 	enum elants_iap_mode iap_mode;
143 
144 	/* Guards against concurrent access to the device via sysfs */
145 	struct mutex sysfs_mutex;
146 
147 	u8 cmd_resp[HEADER_SIZE];
148 	struct completion cmd_done;
149 
150 	bool wake_irq_enabled;
151 	bool keep_power_in_suspend;
152 
153 	/* Must be last to be used for DMA operations */
154 	u8 buf[MAX_PACKET_SIZE] ____cacheline_aligned;
155 };
156 
157 static int elants_i2c_send(struct i2c_client *client,
158 			   const void *data, size_t size)
159 {
160 	int ret;
161 
162 	ret = i2c_master_send(client, data, size);
163 	if (ret == size)
164 		return 0;
165 
166 	if (ret >= 0)
167 		ret = -EIO;
168 
169 	dev_err(&client->dev, "%s failed (%*ph): %d\n",
170 		__func__, (int)size, data, ret);
171 
172 	return ret;
173 }
174 
175 static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
176 {
177 	int ret;
178 
179 	ret = i2c_master_recv(client, data, size);
180 	if (ret == size)
181 		return 0;
182 
183 	if (ret >= 0)
184 		ret = -EIO;
185 
186 	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
187 
188 	return ret;
189 }
190 
191 static int elants_i2c_execute_command(struct i2c_client *client,
192 				      const u8 *cmd, size_t cmd_size,
193 				      u8 *resp, size_t resp_size)
194 {
195 	struct i2c_msg msgs[2];
196 	int ret;
197 	u8 expected_response;
198 
199 	switch (cmd[0]) {
200 	case CMD_HEADER_READ:
201 		expected_response = CMD_HEADER_RESP;
202 		break;
203 
204 	case CMD_HEADER_6B_READ:
205 		expected_response = CMD_HEADER_6B_RESP;
206 		break;
207 
208 	default:
209 		dev_err(&client->dev, "%s: invalid command %*ph\n",
210 			__func__, (int)cmd_size, cmd);
211 		return -EINVAL;
212 	}
213 
214 	msgs[0].addr = client->addr;
215 	msgs[0].flags = client->flags & I2C_M_TEN;
216 	msgs[0].len = cmd_size;
217 	msgs[0].buf = (u8 *)cmd;
218 
219 	msgs[1].addr = client->addr;
220 	msgs[1].flags = client->flags & I2C_M_TEN;
221 	msgs[1].flags |= I2C_M_RD;
222 	msgs[1].len = resp_size;
223 	msgs[1].buf = resp;
224 
225 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
226 	if (ret < 0)
227 		return ret;
228 
229 	if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
230 		return -EIO;
231 
232 	return 0;
233 }
234 
235 static int elants_i2c_calibrate(struct elants_data *ts)
236 {
237 	struct i2c_client *client = ts->client;
238 	int ret, error;
239 	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
240 	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
241 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
242 
243 	disable_irq(client->irq);
244 
245 	ts->state = ELAN_WAIT_RECALIBRATION;
246 	reinit_completion(&ts->cmd_done);
247 
248 	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
249 	elants_i2c_send(client, rek, sizeof(rek));
250 
251 	enable_irq(client->irq);
252 
253 	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
254 				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
255 
256 	ts->state = ELAN_STATE_NORMAL;
257 
258 	if (ret <= 0) {
259 		error = ret < 0 ? ret : -ETIMEDOUT;
260 		dev_err(&client->dev,
261 			"error while waiting for calibration to complete: %d\n",
262 			error);
263 		return error;
264 	}
265 
266 	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
267 		dev_err(&client->dev,
268 			"unexpected calibration response: %*ph\n",
269 			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
270 		return -EINVAL;
271 	}
272 
273 	return 0;
274 }
275 
276 static int elants_i2c_sw_reset(struct i2c_client *client)
277 {
278 	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
279 	int error;
280 
281 	error = elants_i2c_send(client, soft_rst_cmd,
282 				sizeof(soft_rst_cmd));
283 	if (error) {
284 		dev_err(&client->dev, "software reset failed: %d\n", error);
285 		return error;
286 	}
287 
288 	/*
289 	 * We should wait at least 10 msec (but no more than 40) before
290 	 * sending fastboot or IAP command to the device.
291 	 */
292 	msleep(30);
293 
294 	return 0;
295 }
296 
297 static u16 elants_i2c_parse_version(u8 *buf)
298 {
299 	return get_unaligned_be32(buf) >> 4;
300 }
301 
302 static int elants_i2c_query_hw_version(struct elants_data *ts)
303 {
304 	struct i2c_client *client = ts->client;
305 	int error, retry_cnt;
306 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
307 	u8 resp[HEADER_SIZE];
308 
309 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
310 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
311 						   resp, sizeof(resp));
312 		if (!error) {
313 			ts->hw_version = elants_i2c_parse_version(resp);
314 			if (ts->hw_version != 0xffff)
315 				return 0;
316 		}
317 
318 		dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
319 			error, (int)sizeof(resp), resp);
320 	}
321 
322 	if (error) {
323 		dev_err(&client->dev,
324 			"Failed to read fw id: %d\n", error);
325 		return error;
326 	}
327 
328 	dev_err(&client->dev, "Invalid fw id: %#04x\n", ts->hw_version);
329 
330 	return -EINVAL;
331 }
332 
333 static int elants_i2c_query_fw_version(struct elants_data *ts)
334 {
335 	struct i2c_client *client = ts->client;
336 	int error, retry_cnt;
337 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
338 	u8 resp[HEADER_SIZE];
339 
340 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
341 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
342 						   resp, sizeof(resp));
343 		if (!error) {
344 			ts->fw_version = elants_i2c_parse_version(resp);
345 			if (ts->fw_version != 0x0000 &&
346 			    ts->fw_version != 0xffff)
347 				return 0;
348 		}
349 
350 		dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
351 			error, (int)sizeof(resp), resp);
352 	}
353 
354 	dev_err(&client->dev,
355 		"Failed to read fw version or fw version is invalid\n");
356 
357 	return -EINVAL;
358 }
359 
360 static int elants_i2c_query_test_version(struct elants_data *ts)
361 {
362 	struct i2c_client *client = ts->client;
363 	int error, retry_cnt;
364 	u16 version;
365 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
366 	u8 resp[HEADER_SIZE];
367 
368 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
369 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
370 						   resp, sizeof(resp));
371 		if (!error) {
372 			version = elants_i2c_parse_version(resp);
373 			ts->test_version = version >> 8;
374 			ts->solution_version = version & 0xff;
375 
376 			return 0;
377 		}
378 
379 		dev_dbg(&client->dev,
380 			"read test version error rc=%d, buf=%*phC\n",
381 			error, (int)sizeof(resp), resp);
382 	}
383 
384 	dev_err(&client->dev, "Failed to read test version\n");
385 
386 	return -EINVAL;
387 }
388 
389 static int elants_i2c_query_bc_version(struct elants_data *ts)
390 {
391 	struct i2c_client *client = ts->client;
392 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
393 	u8 resp[HEADER_SIZE];
394 	u16 version;
395 	int error;
396 
397 	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
398 					   resp, sizeof(resp));
399 	if (error) {
400 		dev_err(&client->dev,
401 			"read BC version error=%d, buf=%*phC\n",
402 			error, (int)sizeof(resp), resp);
403 		return error;
404 	}
405 
406 	version = elants_i2c_parse_version(resp);
407 	ts->bc_version = version >> 8;
408 	ts->iap_version = version & 0xff;
409 
410 	return 0;
411 }
412 
413 static int elants_i2c_query_ts_info(struct elants_data *ts)
414 {
415 	struct i2c_client *client = ts->client;
416 	int error;
417 	u8 resp[17];
418 	u16 phy_x, phy_y, rows, cols, osr;
419 	const u8 get_resolution_cmd[] = {
420 		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
421 	};
422 	const u8 get_osr_cmd[] = {
423 		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
424 	};
425 	const u8 get_physical_scan_cmd[] = {
426 		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
427 	};
428 	const u8 get_physical_drive_cmd[] = {
429 		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
430 	};
431 
432 	/* Get trace number */
433 	error = elants_i2c_execute_command(client,
434 					   get_resolution_cmd,
435 					   sizeof(get_resolution_cmd),
436 					   resp, sizeof(resp));
437 	if (error) {
438 		dev_err(&client->dev, "get resolution command failed: %d\n",
439 			error);
440 		return error;
441 	}
442 
443 	rows = resp[2] + resp[6] + resp[10];
444 	cols = resp[3] + resp[7] + resp[11];
445 
446 	/* Process mm_to_pixel information */
447 	error = elants_i2c_execute_command(client,
448 					   get_osr_cmd, sizeof(get_osr_cmd),
449 					   resp, sizeof(resp));
450 	if (error) {
451 		dev_err(&client->dev, "get osr command failed: %d\n",
452 			error);
453 		return error;
454 	}
455 
456 	osr = resp[3];
457 
458 	error = elants_i2c_execute_command(client,
459 					   get_physical_scan_cmd,
460 					   sizeof(get_physical_scan_cmd),
461 					   resp, sizeof(resp));
462 	if (error) {
463 		dev_err(&client->dev, "get physical scan command failed: %d\n",
464 			error);
465 		return error;
466 	}
467 
468 	phy_x = get_unaligned_be16(&resp[2]);
469 
470 	error = elants_i2c_execute_command(client,
471 					   get_physical_drive_cmd,
472 					   sizeof(get_physical_drive_cmd),
473 					   resp, sizeof(resp));
474 	if (error) {
475 		dev_err(&client->dev, "get physical drive command failed: %d\n",
476 			error);
477 		return error;
478 	}
479 
480 	phy_y = get_unaligned_be16(&resp[2]);
481 
482 	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
483 
484 	if (rows == 0 || cols == 0 || osr == 0) {
485 		dev_warn(&client->dev,
486 			 "invalid trace number data: %d, %d, %d\n",
487 			 rows, cols, osr);
488 	} else {
489 		/* translate trace number to TS resolution */
490 		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
491 		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
492 		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
493 		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
494 	}
495 
496 	return 0;
497 }
498 
499 static int elants_i2c_fastboot(struct i2c_client *client)
500 {
501 	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
502 	int error;
503 
504 	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
505 	if (error) {
506 		dev_err(&client->dev, "boot failed: %d\n", error);
507 		return error;
508 	}
509 
510 	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
511 	return 0;
512 }
513 
514 static int elants_i2c_initialize(struct elants_data *ts)
515 {
516 	struct i2c_client *client = ts->client;
517 	int error, error2, retry_cnt;
518 	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
519 	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
520 	u8 buf[HEADER_SIZE];
521 
522 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
523 		error = elants_i2c_sw_reset(client);
524 		if (error) {
525 			/* Continue initializing if it's the last try */
526 			if (retry_cnt < MAX_RETRIES - 1)
527 				continue;
528 		}
529 
530 		error = elants_i2c_fastboot(client);
531 		if (error) {
532 			/* Continue initializing if it's the last try */
533 			if (retry_cnt < MAX_RETRIES - 1)
534 				continue;
535 		}
536 
537 		/* Wait for Hello packet */
538 		msleep(BOOT_TIME_DELAY_MS);
539 
540 		error = elants_i2c_read(client, buf, sizeof(buf));
541 		if (error) {
542 			dev_err(&client->dev,
543 				"failed to read 'hello' packet: %d\n", error);
544 		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
545 			ts->iap_mode = ELAN_IAP_OPERATIONAL;
546 			break;
547 		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
548 			/*
549 			 * Setting error code will mark device
550 			 * in recovery mode below.
551 			 */
552 			error = -EIO;
553 			break;
554 		} else {
555 			error = -EINVAL;
556 			dev_err(&client->dev,
557 				"invalid 'hello' packet: %*ph\n",
558 				(int)sizeof(buf), buf);
559 		}
560 	}
561 
562 	/* hw version is available even if device in recovery state */
563 	error2 = elants_i2c_query_hw_version(ts);
564 	if (!error)
565 		error = error2;
566 
567 	if (!error)
568 		error = elants_i2c_query_fw_version(ts);
569 	if (!error)
570 		error = elants_i2c_query_test_version(ts);
571 	if (!error)
572 		error = elants_i2c_query_bc_version(ts);
573 	if (!error)
574 		error = elants_i2c_query_ts_info(ts);
575 
576 	if (error)
577 		ts->iap_mode = ELAN_IAP_RECOVERY;
578 
579 	return 0;
580 }
581 
582 /*
583  * Firmware update interface.
584  */
585 
586 static int elants_i2c_fw_write_page(struct i2c_client *client,
587 				    const void *page)
588 {
589 	const u8 ack_ok[] = { 0xaa, 0xaa };
590 	u8 buf[2];
591 	int retry;
592 	int error;
593 
594 	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
595 		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
596 		if (error) {
597 			dev_err(&client->dev,
598 				"IAP Write Page failed: %d\n", error);
599 			continue;
600 		}
601 
602 		error = elants_i2c_read(client, buf, 2);
603 		if (error) {
604 			dev_err(&client->dev,
605 				"IAP Ack read failed: %d\n", error);
606 			return error;
607 		}
608 
609 		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
610 			return 0;
611 
612 		error = -EIO;
613 		dev_err(&client->dev,
614 			"IAP Get Ack Error [%02x:%02x]\n",
615 			buf[0], buf[1]);
616 	}
617 
618 	return error;
619 }
620 
621 static int elants_i2c_do_update_firmware(struct i2c_client *client,
622 					 const struct firmware *fw,
623 					 bool force)
624 {
625 	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
626 	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
627 	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
628 	const u8 close_idle[] = {0x54, 0x2c, 0x01, 0x01};
629 	u8 buf[HEADER_SIZE];
630 	u16 send_id;
631 	int page, n_fw_pages;
632 	int error;
633 
634 	/* Recovery mode detection! */
635 	if (force) {
636 		dev_dbg(&client->dev, "Recovery mode procedure\n");
637 		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
638 	} else {
639 		/* Start IAP Procedure */
640 		dev_dbg(&client->dev, "Normal IAP procedure\n");
641 		/* Close idle mode */
642 		error = elants_i2c_send(client, close_idle, sizeof(close_idle));
643 		if (error)
644 			dev_err(&client->dev, "Failed close idle: %d\n", error);
645 		msleep(60);
646 		elants_i2c_sw_reset(client);
647 		msleep(20);
648 		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
649 	}
650 
651 	if (error) {
652 		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
653 		return error;
654 	}
655 
656 	msleep(20);
657 
658 	/* check IAP state */
659 	error = elants_i2c_read(client, buf, 4);
660 	if (error) {
661 		dev_err(&client->dev,
662 			"failed to read IAP acknowledgement: %d\n",
663 			error);
664 		return error;
665 	}
666 
667 	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
668 		dev_err(&client->dev,
669 			"failed to enter IAP: %*ph (expected %*ph)\n",
670 			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
671 		return -EIO;
672 	}
673 
674 	dev_info(&client->dev, "successfully entered IAP mode");
675 
676 	send_id = client->addr;
677 	error = elants_i2c_send(client, &send_id, 1);
678 	if (error) {
679 		dev_err(&client->dev, "sending dummy byte failed: %d\n",
680 			error);
681 		return error;
682 	}
683 
684 	/* Clear the last page of Master */
685 	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
686 	if (error) {
687 		dev_err(&client->dev, "clearing of the last page failed: %d\n",
688 			error);
689 		return error;
690 	}
691 
692 	error = elants_i2c_read(client, buf, 2);
693 	if (error) {
694 		dev_err(&client->dev,
695 			"failed to read ACK for clearing the last page: %d\n",
696 			error);
697 		return error;
698 	}
699 
700 	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
701 	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
702 
703 	for (page = 0; page < n_fw_pages; page++) {
704 		error = elants_i2c_fw_write_page(client,
705 					fw->data + page * ELAN_FW_PAGESIZE);
706 		if (error) {
707 			dev_err(&client->dev,
708 				"failed to write FW page %d: %d\n",
709 				page, error);
710 			return error;
711 		}
712 	}
713 
714 	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
715 	msleep(300);
716 
717 	dev_info(&client->dev, "firmware update completed\n");
718 	return 0;
719 }
720 
721 static int elants_i2c_fw_update(struct elants_data *ts)
722 {
723 	struct i2c_client *client = ts->client;
724 	const struct firmware *fw;
725 	char *fw_name;
726 	int error;
727 
728 	fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
729 	if (!fw_name)
730 		return -ENOMEM;
731 
732 	dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
733 	error = request_firmware(&fw, fw_name, &client->dev);
734 	kfree(fw_name);
735 	if (error) {
736 		dev_err(&client->dev, "failed to request firmware: %d\n",
737 			error);
738 		return error;
739 	}
740 
741 	if (fw->size % ELAN_FW_PAGESIZE) {
742 		dev_err(&client->dev, "invalid firmware length: %zu\n",
743 			fw->size);
744 		error = -EINVAL;
745 		goto out;
746 	}
747 
748 	disable_irq(client->irq);
749 
750 	error = elants_i2c_do_update_firmware(client, fw,
751 					ts->iap_mode == ELAN_IAP_RECOVERY);
752 	if (error) {
753 		dev_err(&client->dev, "firmware update failed: %d\n", error);
754 		ts->iap_mode = ELAN_IAP_RECOVERY;
755 		goto out_enable_irq;
756 	}
757 
758 	error = elants_i2c_initialize(ts);
759 	if (error) {
760 		dev_err(&client->dev,
761 			"failed to initialize device after firmware update: %d\n",
762 			error);
763 		ts->iap_mode = ELAN_IAP_RECOVERY;
764 		goto out_enable_irq;
765 	}
766 
767 	ts->iap_mode = ELAN_IAP_OPERATIONAL;
768 
769 out_enable_irq:
770 	ts->state = ELAN_STATE_NORMAL;
771 	enable_irq(client->irq);
772 	msleep(100);
773 
774 	if (!error)
775 		elants_i2c_calibrate(ts);
776 out:
777 	release_firmware(fw);
778 	return error;
779 }
780 
781 /*
782  * Event reporting.
783  */
784 
785 static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
786 {
787 	struct input_dev *input = ts->input;
788 	unsigned int n_fingers;
789 	u16 finger_state;
790 	int i;
791 
792 	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
793 	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
794 			buf[FW_POS_STATE];
795 
796 	dev_dbg(&ts->client->dev,
797 		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
798 
799 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
800 		if (finger_state & 1) {
801 			unsigned int x, y, p, w;
802 			u8 *pos;
803 
804 			pos = &buf[FW_POS_XY + i * 3];
805 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
806 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
807 			p = buf[FW_POS_PRESSURE + i];
808 			w = buf[FW_POS_WIDTH + i];
809 
810 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
811 				i, x, y, p, w);
812 
813 			input_mt_slot(input, i);
814 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
815 			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
816 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
817 			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
818 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
819 
820 			n_fingers--;
821 		}
822 
823 		finger_state >>= 1;
824 	}
825 
826 	input_mt_sync_frame(input);
827 	input_sync(input);
828 }
829 
830 static u8 elants_i2c_calculate_checksum(u8 *buf)
831 {
832 	u8 checksum = 0;
833 	u8 i;
834 
835 	for (i = 0; i < FW_POS_CHECKSUM; i++)
836 		checksum += buf[i];
837 
838 	return checksum;
839 }
840 
841 static void elants_i2c_event(struct elants_data *ts, u8 *buf)
842 {
843 	u8 checksum = elants_i2c_calculate_checksum(buf);
844 
845 	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
846 		dev_warn(&ts->client->dev,
847 			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
848 			 __func__, buf[FW_POS_HEADER],
849 			 checksum, buf[FW_POS_CHECKSUM]);
850 	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
851 		dev_warn(&ts->client->dev,
852 			 "%s: unknown packet type: %02x\n",
853 			 __func__, buf[FW_POS_HEADER]);
854 	else
855 		elants_i2c_mt_event(ts, buf);
856 }
857 
858 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
859 {
860 	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
861 	struct elants_data *ts = _dev;
862 	struct i2c_client *client = ts->client;
863 	int report_count, report_len;
864 	int i;
865 	int len;
866 
867 	len = i2c_master_recv_dmasafe(client, ts->buf, sizeof(ts->buf));
868 	if (len < 0) {
869 		dev_err(&client->dev, "%s: failed to read data: %d\n",
870 			__func__, len);
871 		goto out;
872 	}
873 
874 	dev_dbg(&client->dev, "%s: packet %*ph\n",
875 		__func__, HEADER_SIZE, ts->buf);
876 
877 	switch (ts->state) {
878 	case ELAN_WAIT_RECALIBRATION:
879 		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
880 			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
881 			complete(&ts->cmd_done);
882 			ts->state = ELAN_STATE_NORMAL;
883 		}
884 		break;
885 
886 	case ELAN_WAIT_QUEUE_HEADER:
887 		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
888 			break;
889 
890 		ts->state = ELAN_STATE_NORMAL;
891 		/* fall through */
892 
893 	case ELAN_STATE_NORMAL:
894 
895 		switch (ts->buf[FW_HDR_TYPE]) {
896 		case CMD_HEADER_HELLO:
897 		case CMD_HEADER_RESP:
898 		case CMD_HEADER_REK:
899 			break;
900 
901 		case QUEUE_HEADER_WAIT:
902 			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
903 				dev_err(&client->dev,
904 					"invalid wait packet %*ph\n",
905 					HEADER_SIZE, ts->buf);
906 			} else {
907 				ts->state = ELAN_WAIT_QUEUE_HEADER;
908 				udelay(30);
909 			}
910 			break;
911 
912 		case QUEUE_HEADER_SINGLE:
913 			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
914 			break;
915 
916 		case QUEUE_HEADER_NORMAL:
917 			report_count = ts->buf[FW_HDR_COUNT];
918 			if (report_count == 0 || report_count > 3) {
919 				dev_err(&client->dev,
920 					"bad report count: %*ph\n",
921 					HEADER_SIZE, ts->buf);
922 				break;
923 			}
924 
925 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
926 			if (report_len != PACKET_SIZE) {
927 				dev_err(&client->dev,
928 					"mismatching report length: %*ph\n",
929 					HEADER_SIZE, ts->buf);
930 				break;
931 			}
932 
933 			for (i = 0; i < report_count; i++) {
934 				u8 *buf = ts->buf + HEADER_SIZE +
935 							i * PACKET_SIZE;
936 				elants_i2c_event(ts, buf);
937 			}
938 			break;
939 
940 		default:
941 			dev_err(&client->dev, "unknown packet %*ph\n",
942 				HEADER_SIZE, ts->buf);
943 			break;
944 		}
945 		break;
946 	}
947 
948 out:
949 	return IRQ_HANDLED;
950 }
951 
952 /*
953  * sysfs interface
954  */
955 static ssize_t calibrate_store(struct device *dev,
956 			       struct device_attribute *attr,
957 			      const char *buf, size_t count)
958 {
959 	struct i2c_client *client = to_i2c_client(dev);
960 	struct elants_data *ts = i2c_get_clientdata(client);
961 	int error;
962 
963 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
964 	if (error)
965 		return error;
966 
967 	error = elants_i2c_calibrate(ts);
968 
969 	mutex_unlock(&ts->sysfs_mutex);
970 	return error ?: count;
971 }
972 
973 static ssize_t write_update_fw(struct device *dev,
974 			       struct device_attribute *attr,
975 			       const char *buf, size_t count)
976 {
977 	struct i2c_client *client = to_i2c_client(dev);
978 	struct elants_data *ts = i2c_get_clientdata(client);
979 	int error;
980 
981 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
982 	if (error)
983 		return error;
984 
985 	error = elants_i2c_fw_update(ts);
986 	dev_dbg(dev, "firmware update result: %d\n", error);
987 
988 	mutex_unlock(&ts->sysfs_mutex);
989 	return error ?: count;
990 }
991 
992 static ssize_t show_iap_mode(struct device *dev,
993 			     struct device_attribute *attr, char *buf)
994 {
995 	struct i2c_client *client = to_i2c_client(dev);
996 	struct elants_data *ts = i2c_get_clientdata(client);
997 
998 	return sprintf(buf, "%s\n",
999 		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
1000 				"Normal" : "Recovery");
1001 }
1002 
1003 static DEVICE_ATTR_WO(calibrate);
1004 static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
1005 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
1006 
1007 struct elants_version_attribute {
1008 	struct device_attribute dattr;
1009 	size_t field_offset;
1010 	size_t field_size;
1011 };
1012 
1013 #define __ELANTS_FIELD_SIZE(_field)					\
1014 	sizeof(((struct elants_data *)NULL)->_field)
1015 #define __ELANTS_VERIFY_SIZE(_field)					\
1016 	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
1017 	 __ELANTS_FIELD_SIZE(_field))
1018 #define ELANTS_VERSION_ATTR(_field)					\
1019 	struct elants_version_attribute elants_ver_attr_##_field = {	\
1020 		.dattr = __ATTR(_field, S_IRUGO,			\
1021 				elants_version_attribute_show, NULL),	\
1022 		.field_offset = offsetof(struct elants_data, _field),	\
1023 		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
1024 	}
1025 
1026 static ssize_t elants_version_attribute_show(struct device *dev,
1027 					     struct device_attribute *dattr,
1028 					     char *buf)
1029 {
1030 	struct i2c_client *client = to_i2c_client(dev);
1031 	struct elants_data *ts = i2c_get_clientdata(client);
1032 	struct elants_version_attribute *attr =
1033 		container_of(dattr, struct elants_version_attribute, dattr);
1034 	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1035 	unsigned int fmt_size;
1036 	unsigned int val;
1037 
1038 	if (attr->field_size == 1) {
1039 		val = *field;
1040 		fmt_size = 2; /* 2 HEX digits */
1041 	} else {
1042 		val = *(u16 *)field;
1043 		fmt_size = 4; /* 4 HEX digits */
1044 	}
1045 
1046 	return sprintf(buf, "%0*x\n", fmt_size, val);
1047 }
1048 
1049 static ELANTS_VERSION_ATTR(fw_version);
1050 static ELANTS_VERSION_ATTR(hw_version);
1051 static ELANTS_VERSION_ATTR(test_version);
1052 static ELANTS_VERSION_ATTR(solution_version);
1053 static ELANTS_VERSION_ATTR(bc_version);
1054 static ELANTS_VERSION_ATTR(iap_version);
1055 
1056 static struct attribute *elants_attributes[] = {
1057 	&dev_attr_calibrate.attr,
1058 	&dev_attr_update_fw.attr,
1059 	&dev_attr_iap_mode.attr,
1060 
1061 	&elants_ver_attr_fw_version.dattr.attr,
1062 	&elants_ver_attr_hw_version.dattr.attr,
1063 	&elants_ver_attr_test_version.dattr.attr,
1064 	&elants_ver_attr_solution_version.dattr.attr,
1065 	&elants_ver_attr_bc_version.dattr.attr,
1066 	&elants_ver_attr_iap_version.dattr.attr,
1067 	NULL
1068 };
1069 
1070 static const struct attribute_group elants_attribute_group = {
1071 	.attrs = elants_attributes,
1072 };
1073 
1074 static int elants_i2c_power_on(struct elants_data *ts)
1075 {
1076 	int error;
1077 
1078 	/*
1079 	 * If we do not have reset gpio assume platform firmware
1080 	 * controls regulators and does power them on for us.
1081 	 */
1082 	if (IS_ERR_OR_NULL(ts->reset_gpio))
1083 		return 0;
1084 
1085 	gpiod_set_value_cansleep(ts->reset_gpio, 1);
1086 
1087 	error = regulator_enable(ts->vcc33);
1088 	if (error) {
1089 		dev_err(&ts->client->dev,
1090 			"failed to enable vcc33 regulator: %d\n",
1091 			error);
1092 		goto release_reset_gpio;
1093 	}
1094 
1095 	error = regulator_enable(ts->vccio);
1096 	if (error) {
1097 		dev_err(&ts->client->dev,
1098 			"failed to enable vccio regulator: %d\n",
1099 			error);
1100 		regulator_disable(ts->vcc33);
1101 		goto release_reset_gpio;
1102 	}
1103 
1104 	/*
1105 	 * We need to wait a bit after powering on controller before
1106 	 * we are allowed to release reset GPIO.
1107 	 */
1108 	udelay(ELAN_POWERON_DELAY_USEC);
1109 
1110 release_reset_gpio:
1111 	gpiod_set_value_cansleep(ts->reset_gpio, 0);
1112 	if (error)
1113 		return error;
1114 
1115 	msleep(ELAN_RESET_DELAY_MSEC);
1116 
1117 	return 0;
1118 }
1119 
1120 static void elants_i2c_power_off(void *_data)
1121 {
1122 	struct elants_data *ts = _data;
1123 
1124 	if (!IS_ERR_OR_NULL(ts->reset_gpio)) {
1125 		/*
1126 		 * Activate reset gpio to prevent leakage through the
1127 		 * pin once we shut off power to the controller.
1128 		 */
1129 		gpiod_set_value_cansleep(ts->reset_gpio, 1);
1130 		regulator_disable(ts->vccio);
1131 		regulator_disable(ts->vcc33);
1132 	}
1133 }
1134 
1135 static int elants_i2c_probe(struct i2c_client *client,
1136 			    const struct i2c_device_id *id)
1137 {
1138 	union i2c_smbus_data dummy;
1139 	struct elants_data *ts;
1140 	unsigned long irqflags;
1141 	int error;
1142 
1143 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1144 		dev_err(&client->dev,
1145 			"%s: i2c check functionality error\n", DEVICE_NAME);
1146 		return -ENXIO;
1147 	}
1148 
1149 	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1150 	if (!ts)
1151 		return -ENOMEM;
1152 
1153 	mutex_init(&ts->sysfs_mutex);
1154 	init_completion(&ts->cmd_done);
1155 
1156 	ts->client = client;
1157 	i2c_set_clientdata(client, ts);
1158 
1159 	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
1160 	if (IS_ERR(ts->vcc33)) {
1161 		error = PTR_ERR(ts->vcc33);
1162 		if (error != -EPROBE_DEFER)
1163 			dev_err(&client->dev,
1164 				"Failed to get 'vcc33' regulator: %d\n",
1165 				error);
1166 		return error;
1167 	}
1168 
1169 	ts->vccio = devm_regulator_get(&client->dev, "vccio");
1170 	if (IS_ERR(ts->vccio)) {
1171 		error = PTR_ERR(ts->vccio);
1172 		if (error != -EPROBE_DEFER)
1173 			dev_err(&client->dev,
1174 				"Failed to get 'vccio' regulator: %d\n",
1175 				error);
1176 		return error;
1177 	}
1178 
1179 	ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW);
1180 	if (IS_ERR(ts->reset_gpio)) {
1181 		error = PTR_ERR(ts->reset_gpio);
1182 
1183 		if (error == -EPROBE_DEFER)
1184 			return error;
1185 
1186 		if (error != -ENOENT && error != -ENOSYS) {
1187 			dev_err(&client->dev,
1188 				"failed to get reset gpio: %d\n",
1189 				error);
1190 			return error;
1191 		}
1192 
1193 		ts->keep_power_in_suspend = true;
1194 	}
1195 
1196 	error = elants_i2c_power_on(ts);
1197 	if (error)
1198 		return error;
1199 
1200 	error = devm_add_action(&client->dev, elants_i2c_power_off, ts);
1201 	if (error) {
1202 		dev_err(&client->dev,
1203 			"failed to install power off action: %d\n", error);
1204 		elants_i2c_power_off(ts);
1205 		return error;
1206 	}
1207 
1208 	/* Make sure there is something at this address */
1209 	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1210 			   I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1211 		dev_err(&client->dev, "nothing at this address\n");
1212 		return -ENXIO;
1213 	}
1214 
1215 	error = elants_i2c_initialize(ts);
1216 	if (error) {
1217 		dev_err(&client->dev, "failed to initialize: %d\n", error);
1218 		return error;
1219 	}
1220 
1221 	ts->input = devm_input_allocate_device(&client->dev);
1222 	if (!ts->input) {
1223 		dev_err(&client->dev, "Failed to allocate input device\n");
1224 		return -ENOMEM;
1225 	}
1226 
1227 	ts->input->name = "Elan Touchscreen";
1228 	ts->input->id.bustype = BUS_I2C;
1229 
1230 	__set_bit(BTN_TOUCH, ts->input->keybit);
1231 	__set_bit(EV_ABS, ts->input->evbit);
1232 	__set_bit(EV_KEY, ts->input->evbit);
1233 
1234 	/* Single touch input params setup */
1235 	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1236 	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1237 	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1238 	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1239 	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1240 
1241 	/* Multitouch input params setup */
1242 	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1243 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1244 	if (error) {
1245 		dev_err(&client->dev,
1246 			"failed to initialize MT slots: %d\n", error);
1247 		return error;
1248 	}
1249 
1250 	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1251 	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1252 	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1253 	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1254 	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1255 	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1256 
1257 	error = input_register_device(ts->input);
1258 	if (error) {
1259 		dev_err(&client->dev,
1260 			"unable to register input device: %d\n", error);
1261 		return error;
1262 	}
1263 
1264 	/*
1265 	 * Platform code (ACPI, DTS) should normally set up interrupt
1266 	 * for us, but in case it did not let's fall back to using falling
1267 	 * edge to be compatible with older Chromebooks.
1268 	 */
1269 	irqflags = irq_get_trigger_type(client->irq);
1270 	if (!irqflags)
1271 		irqflags = IRQF_TRIGGER_FALLING;
1272 
1273 	error = devm_request_threaded_irq(&client->dev, client->irq,
1274 					  NULL, elants_i2c_irq,
1275 					  irqflags | IRQF_ONESHOT,
1276 					  client->name, ts);
1277 	if (error) {
1278 		dev_err(&client->dev, "Failed to register interrupt\n");
1279 		return error;
1280 	}
1281 
1282 	/*
1283 	 * Systems using device tree should set up wakeup via DTS,
1284 	 * the rest will configure device as wakeup source by default.
1285 	 */
1286 	if (!client->dev.of_node)
1287 		device_init_wakeup(&client->dev, true);
1288 
1289 	error = devm_device_add_group(&client->dev, &elants_attribute_group);
1290 	if (error) {
1291 		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1292 			error);
1293 		return error;
1294 	}
1295 
1296 	return 0;
1297 }
1298 
1299 static int __maybe_unused elants_i2c_suspend(struct device *dev)
1300 {
1301 	struct i2c_client *client = to_i2c_client(dev);
1302 	struct elants_data *ts = i2c_get_clientdata(client);
1303 	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1304 	int retry_cnt;
1305 	int error;
1306 
1307 	/* Command not support in IAP recovery mode */
1308 	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1309 		return -EBUSY;
1310 
1311 	disable_irq(client->irq);
1312 
1313 	if (device_may_wakeup(dev)) {
1314 		/*
1315 		 * The device will automatically enter idle mode
1316 		 * that has reduced power consumption.
1317 		 */
1318 		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1319 	} else if (ts->keep_power_in_suspend) {
1320 		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1321 			error = elants_i2c_send(client, set_sleep_cmd,
1322 						sizeof(set_sleep_cmd));
1323 			if (!error)
1324 				break;
1325 
1326 			dev_err(&client->dev,
1327 				"suspend command failed: %d\n", error);
1328 		}
1329 	} else {
1330 		elants_i2c_power_off(ts);
1331 	}
1332 
1333 	return 0;
1334 }
1335 
1336 static int __maybe_unused elants_i2c_resume(struct device *dev)
1337 {
1338 	struct i2c_client *client = to_i2c_client(dev);
1339 	struct elants_data *ts = i2c_get_clientdata(client);
1340 	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1341 	int retry_cnt;
1342 	int error;
1343 
1344 	if (device_may_wakeup(dev)) {
1345 		if (ts->wake_irq_enabled)
1346 			disable_irq_wake(client->irq);
1347 		elants_i2c_sw_reset(client);
1348 	} else if (ts->keep_power_in_suspend) {
1349 		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1350 			error = elants_i2c_send(client, set_active_cmd,
1351 						sizeof(set_active_cmd));
1352 			if (!error)
1353 				break;
1354 
1355 			dev_err(&client->dev,
1356 				"resume command failed: %d\n", error);
1357 		}
1358 	} else {
1359 		elants_i2c_power_on(ts);
1360 		elants_i2c_initialize(ts);
1361 	}
1362 
1363 	ts->state = ELAN_STATE_NORMAL;
1364 	enable_irq(client->irq);
1365 
1366 	return 0;
1367 }
1368 
1369 static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1370 			 elants_i2c_suspend, elants_i2c_resume);
1371 
1372 static const struct i2c_device_id elants_i2c_id[] = {
1373 	{ DEVICE_NAME, 0 },
1374 	{ }
1375 };
1376 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1377 
1378 #ifdef CONFIG_ACPI
1379 static const struct acpi_device_id elants_acpi_id[] = {
1380 	{ "ELAN0001", 0 },
1381 	{ }
1382 };
1383 MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1384 #endif
1385 
1386 #ifdef CONFIG_OF
1387 static const struct of_device_id elants_of_match[] = {
1388 	{ .compatible = "elan,ekth3500" },
1389 	{ /* sentinel */ }
1390 };
1391 MODULE_DEVICE_TABLE(of, elants_of_match);
1392 #endif
1393 
1394 static struct i2c_driver elants_i2c_driver = {
1395 	.probe = elants_i2c_probe,
1396 	.id_table = elants_i2c_id,
1397 	.driver = {
1398 		.name = DEVICE_NAME,
1399 		.pm = &elants_i2c_pm_ops,
1400 		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1401 		.of_match_table = of_match_ptr(elants_of_match),
1402 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1403 	},
1404 };
1405 module_i2c_driver(elants_i2c_driver);
1406 
1407 MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1408 MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1409 MODULE_LICENSE("GPL");
1410