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/platform_device.h>
31 #include <linux/async.h>
32 #include <linux/i2c.h>
33 #include <linux/delay.h>
34 #include <linux/uaccess.h>
35 #include <linux/buffer_head.h>
36 #include <linux/version.h>
37 #include <linux/slab.h>
38 #include <linux/firmware.h>
39 #include <linux/version.h>
40 #include <linux/input/mt.h>
41 #include <linux/acpi.h>
42 #include <linux/of.h>
43 #include <asm/unaligned.h>
44 
45 /* Device, Driver information */
46 #define DEVICE_NAME	"elants_i2c"
47 #define DRV_VERSION	"1.0.9"
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 #define ELAN_FW_FILENAME	"elants_i2c.bin"
104 
105 /* calibration timeout definition */
106 #define ELAN_CALI_TIMEOUT_MSEC	10000
107 
108 enum elants_state {
109 	ELAN_STATE_NORMAL,
110 	ELAN_WAIT_QUEUE_HEADER,
111 	ELAN_WAIT_RECALIBRATION,
112 };
113 
114 enum elants_iap_mode {
115 	ELAN_IAP_OPERATIONAL,
116 	ELAN_IAP_RECOVERY,
117 };
118 
119 /* struct elants_data - represents state of Elan touchscreen device */
120 struct elants_data {
121 	struct i2c_client *client;
122 	struct input_dev *input;
123 
124 	u16 fw_version;
125 	u8 test_version;
126 	u8 solution_version;
127 	u8 bc_version;
128 	u8 iap_version;
129 	u16 hw_version;
130 	unsigned int x_res;	/* resolution in units/mm */
131 	unsigned int y_res;
132 	unsigned int x_max;
133 	unsigned int y_max;
134 
135 	enum elants_state state;
136 	enum elants_iap_mode iap_mode;
137 
138 	/* Guards against concurrent access to the device via sysfs */
139 	struct mutex sysfs_mutex;
140 
141 	u8 cmd_resp[HEADER_SIZE];
142 	struct completion cmd_done;
143 
144 	u8 buf[MAX_PACKET_SIZE];
145 
146 	bool wake_irq_enabled;
147 };
148 
149 static int elants_i2c_send(struct i2c_client *client,
150 			   const void *data, size_t size)
151 {
152 	int ret;
153 
154 	ret = i2c_master_send(client, data, size);
155 	if (ret == size)
156 		return 0;
157 
158 	if (ret >= 0)
159 		ret = -EIO;
160 
161 	dev_err(&client->dev, "%s failed (%*ph): %d\n",
162 		__func__, (int)size, data, ret);
163 
164 	return ret;
165 }
166 
167 static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
168 {
169 	int ret;
170 
171 	ret = i2c_master_recv(client, data, size);
172 	if (ret == size)
173 		return 0;
174 
175 	if (ret >= 0)
176 		ret = -EIO;
177 
178 	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
179 
180 	return ret;
181 }
182 
183 static int elants_i2c_execute_command(struct i2c_client *client,
184 				      const u8 *cmd, size_t cmd_size,
185 				      u8 *resp, size_t resp_size)
186 {
187 	struct i2c_msg msgs[2];
188 	int ret;
189 	u8 expected_response;
190 
191 	switch (cmd[0]) {
192 	case CMD_HEADER_READ:
193 		expected_response = CMD_HEADER_RESP;
194 		break;
195 
196 	case CMD_HEADER_6B_READ:
197 		expected_response = CMD_HEADER_6B_RESP;
198 		break;
199 
200 	default:
201 		dev_err(&client->dev, "%s: invalid command %*ph\n",
202 			__func__, (int)cmd_size, cmd);
203 		return -EINVAL;
204 	}
205 
206 	msgs[0].addr = client->addr;
207 	msgs[0].flags = client->flags & I2C_M_TEN;
208 	msgs[0].len = cmd_size;
209 	msgs[0].buf = (u8 *)cmd;
210 
211 	msgs[1].addr = client->addr;
212 	msgs[1].flags = client->flags & I2C_M_TEN;
213 	msgs[1].flags |= I2C_M_RD;
214 	msgs[1].len = resp_size;
215 	msgs[1].buf = resp;
216 
217 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
218 	if (ret < 0)
219 		return ret;
220 
221 	if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
222 		return -EIO;
223 
224 	return 0;
225 }
226 
227 static int elants_i2c_calibrate(struct elants_data *ts)
228 {
229 	struct i2c_client *client = ts->client;
230 	int ret, error;
231 	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
232 	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
233 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
234 
235 	disable_irq(client->irq);
236 
237 	ts->state = ELAN_WAIT_RECALIBRATION;
238 	reinit_completion(&ts->cmd_done);
239 
240 	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
241 	elants_i2c_send(client, rek, sizeof(rek));
242 
243 	enable_irq(client->irq);
244 
245 	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
246 				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
247 
248 	ts->state = ELAN_STATE_NORMAL;
249 
250 	if (ret <= 0) {
251 		error = ret < 0 ? ret : -ETIMEDOUT;
252 		dev_err(&client->dev,
253 			"error while waiting for calibration to complete: %d\n",
254 			error);
255 		return error;
256 	}
257 
258 	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
259 		dev_err(&client->dev,
260 			"unexpected calibration response: %*ph\n",
261 			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
262 		return -EINVAL;
263 	}
264 
265 	return 0;
266 }
267 
268 static int elants_i2c_sw_reset(struct i2c_client *client)
269 {
270 	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
271 	int error;
272 
273 	error = elants_i2c_send(client, soft_rst_cmd,
274 				sizeof(soft_rst_cmd));
275 	if (error) {
276 		dev_err(&client->dev, "software reset failed: %d\n", error);
277 		return error;
278 	}
279 
280 	/*
281 	 * We should wait at least 10 msec (but no more than 40) before
282 	 * sending fastboot or IAP command to the device.
283 	 */
284 	msleep(30);
285 
286 	return 0;
287 }
288 
289 static u16 elants_i2c_parse_version(u8 *buf)
290 {
291 	return get_unaligned_be32(buf) >> 4;
292 }
293 
294 static int elants_i2c_query_fw_id(struct elants_data *ts)
295 {
296 	struct i2c_client *client = ts->client;
297 	int error, retry_cnt;
298 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
299 	u8 resp[HEADER_SIZE];
300 
301 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
302 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
303 						   resp, sizeof(resp));
304 		if (!error) {
305 			ts->hw_version = elants_i2c_parse_version(resp);
306 			if (ts->hw_version != 0xffff)
307 				return 0;
308 		}
309 
310 		dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
311 			error, (int)sizeof(resp), resp);
312 	}
313 
314 	dev_err(&client->dev,
315 		"Failed to read fw id or fw id is invalid\n");
316 
317 	return -EINVAL;
318 }
319 
320 static int elants_i2c_query_fw_version(struct elants_data *ts)
321 {
322 	struct i2c_client *client = ts->client;
323 	int error, retry_cnt;
324 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
325 	u8 resp[HEADER_SIZE];
326 
327 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
328 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
329 						   resp, sizeof(resp));
330 		if (!error) {
331 			ts->fw_version = elants_i2c_parse_version(resp);
332 			if (ts->fw_version != 0x0000 &&
333 			    ts->fw_version != 0xffff)
334 				return 0;
335 		}
336 
337 		dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
338 			error, (int)sizeof(resp), resp);
339 	}
340 
341 	dev_err(&client->dev,
342 		"Failed to read fw version or fw version is invalid\n");
343 
344 	return -EINVAL;
345 }
346 
347 static int elants_i2c_query_test_version(struct elants_data *ts)
348 {
349 	struct i2c_client *client = ts->client;
350 	int error, retry_cnt;
351 	u16 version;
352 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
353 	u8 resp[HEADER_SIZE];
354 
355 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
356 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
357 						   resp, sizeof(resp));
358 		if (!error) {
359 			version = elants_i2c_parse_version(resp);
360 			ts->test_version = version >> 8;
361 			ts->solution_version = version & 0xff;
362 
363 			return 0;
364 		}
365 
366 		dev_dbg(&client->dev,
367 			"read test version error rc=%d, buf=%*phC\n",
368 			error, (int)sizeof(resp), resp);
369 	}
370 
371 	dev_err(&client->dev, "Failed to read test version\n");
372 
373 	return -EINVAL;
374 }
375 
376 static int elants_i2c_query_bc_version(struct elants_data *ts)
377 {
378 	struct i2c_client *client = ts->client;
379 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
380 	u8 resp[HEADER_SIZE];
381 	u16 version;
382 	int error;
383 
384 	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
385 					   resp, sizeof(resp));
386 	if (error) {
387 		dev_err(&client->dev,
388 			"read BC version error=%d, buf=%*phC\n",
389 			error, (int)sizeof(resp), resp);
390 		return error;
391 	}
392 
393 	version = elants_i2c_parse_version(resp);
394 	ts->bc_version = version >> 8;
395 	ts->iap_version = version & 0xff;
396 
397 	return 0;
398 }
399 
400 static int elants_i2c_query_ts_info(struct elants_data *ts)
401 {
402 	struct i2c_client *client = ts->client;
403 	int error;
404 	u8 resp[17];
405 	u16 phy_x, phy_y, rows, cols, osr;
406 	const u8 get_resolution_cmd[] = {
407 		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
408 	};
409 	const u8 get_osr_cmd[] = {
410 		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
411 	};
412 	const u8 get_physical_scan_cmd[] = {
413 		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
414 	};
415 	const u8 get_physical_drive_cmd[] = {
416 		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
417 	};
418 
419 	/* Get trace number */
420 	error = elants_i2c_execute_command(client,
421 					   get_resolution_cmd,
422 					   sizeof(get_resolution_cmd),
423 					   resp, sizeof(resp));
424 	if (error) {
425 		dev_err(&client->dev, "get resolution command failed: %d\n",
426 			error);
427 		return error;
428 	}
429 
430 	rows = resp[2] + resp[6] + resp[10];
431 	cols = resp[3] + resp[7] + resp[11];
432 
433 	/* Process mm_to_pixel information */
434 	error = elants_i2c_execute_command(client,
435 					   get_osr_cmd, sizeof(get_osr_cmd),
436 					   resp, sizeof(resp));
437 	if (error) {
438 		dev_err(&client->dev, "get osr command failed: %d\n",
439 			error);
440 		return error;
441 	}
442 
443 	osr = resp[3];
444 
445 	error = elants_i2c_execute_command(client,
446 					   get_physical_scan_cmd,
447 					   sizeof(get_physical_scan_cmd),
448 					   resp, sizeof(resp));
449 	if (error) {
450 		dev_err(&client->dev, "get physical scan command failed: %d\n",
451 			error);
452 		return error;
453 	}
454 
455 	phy_x = get_unaligned_be16(&resp[2]);
456 
457 	error = elants_i2c_execute_command(client,
458 					   get_physical_drive_cmd,
459 					   sizeof(get_physical_drive_cmd),
460 					   resp, sizeof(resp));
461 	if (error) {
462 		dev_err(&client->dev, "get physical drive command failed: %d\n",
463 			error);
464 		return error;
465 	}
466 
467 	phy_y = get_unaligned_be16(&resp[2]);
468 
469 	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
470 
471 	if (rows == 0 || cols == 0 || osr == 0) {
472 		dev_warn(&client->dev,
473 			 "invalid trace number data: %d, %d, %d\n",
474 			 rows, cols, osr);
475 	} else {
476 		/* translate trace number to TS resolution */
477 		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
478 		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
479 		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
480 		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
481 	}
482 
483 	return 0;
484 }
485 
486 static int elants_i2c_fastboot(struct i2c_client *client)
487 {
488 	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
489 	int error;
490 
491 	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
492 	if (error) {
493 		dev_err(&client->dev, "boot failed: %d\n", error);
494 		return error;
495 	}
496 
497 	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
498 	return 0;
499 }
500 
501 static int elants_i2c_initialize(struct elants_data *ts)
502 {
503 	struct i2c_client *client = ts->client;
504 	int error, retry_cnt;
505 	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
506 	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
507 	u8 buf[HEADER_SIZE];
508 
509 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
510 		error = elants_i2c_sw_reset(client);
511 		if (error) {
512 			/* Continue initializing if it's the last try */
513 			if (retry_cnt < MAX_RETRIES - 1)
514 				continue;
515 		}
516 
517 		error = elants_i2c_fastboot(client);
518 		if (error) {
519 			/* Continue initializing if it's the last try */
520 			if (retry_cnt < MAX_RETRIES - 1)
521 				continue;
522 		}
523 
524 		/* Wait for Hello packet */
525 		msleep(BOOT_TIME_DELAY_MS);
526 
527 		error = elants_i2c_read(client, buf, sizeof(buf));
528 		if (error) {
529 			dev_err(&client->dev,
530 				"failed to read 'hello' packet: %d\n", error);
531 		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
532 			ts->iap_mode = ELAN_IAP_OPERATIONAL;
533 			break;
534 		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
535 			/*
536 			 * Setting error code will mark device
537 			 * in recovery mode below.
538 			 */
539 			error = -EIO;
540 			break;
541 		} else {
542 			error = -EINVAL;
543 			dev_err(&client->dev,
544 				"invalid 'hello' packet: %*ph\n",
545 				(int)sizeof(buf), buf);
546 		}
547 	}
548 
549 	if (!error)
550 		error = elants_i2c_query_fw_id(ts);
551 	if (!error)
552 		error = elants_i2c_query_fw_version(ts);
553 
554 	if (error) {
555 		ts->iap_mode = ELAN_IAP_RECOVERY;
556 	} else {
557 		elants_i2c_query_test_version(ts);
558 		elants_i2c_query_bc_version(ts);
559 		elants_i2c_query_ts_info(ts);
560 	}
561 
562 	return 0;
563 }
564 
565 /*
566  * Firmware update interface.
567  */
568 
569 static int elants_i2c_fw_write_page(struct i2c_client *client,
570 				    const void *page)
571 {
572 	const u8 ack_ok[] = { 0xaa, 0xaa };
573 	u8 buf[2];
574 	int retry;
575 	int error;
576 
577 	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
578 		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
579 		if (error) {
580 			dev_err(&client->dev,
581 				"IAP Write Page failed: %d\n", error);
582 			continue;
583 		}
584 
585 		error = elants_i2c_read(client, buf, 2);
586 		if (error) {
587 			dev_err(&client->dev,
588 				"IAP Ack read failed: %d\n", error);
589 			return error;
590 		}
591 
592 		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
593 			return 0;
594 
595 		error = -EIO;
596 		dev_err(&client->dev,
597 			"IAP Get Ack Error [%02x:%02x]\n",
598 			buf[0], buf[1]);
599 	}
600 
601 	return error;
602 }
603 
604 static int elants_i2c_do_update_firmware(struct i2c_client *client,
605 					 const struct firmware *fw,
606 					 bool force)
607 {
608 	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
609 	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
610 	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
611 	u8 buf[HEADER_SIZE];
612 	u16 send_id;
613 	int page, n_fw_pages;
614 	int error;
615 
616 	/* Recovery mode detection! */
617 	if (force) {
618 		dev_dbg(&client->dev, "Recovery mode procedure\n");
619 		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
620 	} else {
621 		/* Start IAP Procedure */
622 		dev_dbg(&client->dev, "Normal IAP procedure\n");
623 		elants_i2c_sw_reset(client);
624 
625 		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
626 	}
627 
628 	if (error) {
629 		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
630 		return error;
631 	}
632 
633 	msleep(20);
634 
635 	/* check IAP state */
636 	error = elants_i2c_read(client, buf, 4);
637 	if (error) {
638 		dev_err(&client->dev,
639 			"failed to read IAP acknowledgement: %d\n",
640 			error);
641 		return error;
642 	}
643 
644 	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
645 		dev_err(&client->dev,
646 			"failed to enter IAP: %*ph (expected %*ph)\n",
647 			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
648 		return -EIO;
649 	}
650 
651 	dev_info(&client->dev, "successfully entered IAP mode");
652 
653 	send_id = client->addr;
654 	error = elants_i2c_send(client, &send_id, 1);
655 	if (error) {
656 		dev_err(&client->dev, "sending dummy byte failed: %d\n",
657 			error);
658 		return error;
659 	}
660 
661 	/* Clear the last page of Master */
662 	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
663 	if (error) {
664 		dev_err(&client->dev, "clearing of the last page failed: %d\n",
665 			error);
666 		return error;
667 	}
668 
669 	error = elants_i2c_read(client, buf, 2);
670 	if (error) {
671 		dev_err(&client->dev,
672 			"failed to read ACK for clearing the last page: %d\n",
673 			error);
674 		return error;
675 	}
676 
677 	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
678 	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
679 
680 	for (page = 0; page < n_fw_pages; page++) {
681 		error = elants_i2c_fw_write_page(client,
682 					fw->data + page * ELAN_FW_PAGESIZE);
683 		if (error) {
684 			dev_err(&client->dev,
685 				"failed to write FW page %d: %d\n",
686 				page, error);
687 			return error;
688 		}
689 	}
690 
691 	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
692 	msleep(300);
693 
694 	dev_info(&client->dev, "firmware update completed\n");
695 	return 0;
696 }
697 
698 static int elants_i2c_fw_update(struct elants_data *ts)
699 {
700 	struct i2c_client *client = ts->client;
701 	const struct firmware *fw;
702 	int error;
703 
704 	error = request_firmware(&fw, ELAN_FW_FILENAME, &client->dev);
705 	if (error) {
706 		dev_err(&client->dev, "failed to request firmware %s: %d\n",
707 			ELAN_FW_FILENAME, error);
708 		return error;
709 	}
710 
711 	if (fw->size % ELAN_FW_PAGESIZE) {
712 		dev_err(&client->dev, "invalid firmware length: %zu\n",
713 			fw->size);
714 		error = -EINVAL;
715 		goto out;
716 	}
717 
718 	disable_irq(client->irq);
719 
720 	error = elants_i2c_do_update_firmware(client, fw,
721 					ts->iap_mode == ELAN_IAP_RECOVERY);
722 	if (error) {
723 		dev_err(&client->dev, "firmware update failed: %d\n", error);
724 		ts->iap_mode = ELAN_IAP_RECOVERY;
725 		goto out_enable_irq;
726 	}
727 
728 	error = elants_i2c_initialize(ts);
729 	if (error) {
730 		dev_err(&client->dev,
731 			"failed to initialize device after firmware update: %d\n",
732 			error);
733 		ts->iap_mode = ELAN_IAP_RECOVERY;
734 		goto out_enable_irq;
735 	}
736 
737 	ts->iap_mode = ELAN_IAP_OPERATIONAL;
738 
739 out_enable_irq:
740 	ts->state = ELAN_STATE_NORMAL;
741 	enable_irq(client->irq);
742 	msleep(100);
743 
744 	if (!error)
745 		elants_i2c_calibrate(ts);
746 out:
747 	release_firmware(fw);
748 	return error;
749 }
750 
751 /*
752  * Event reporting.
753  */
754 
755 static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
756 {
757 	struct input_dev *input = ts->input;
758 	unsigned int n_fingers;
759 	u16 finger_state;
760 	int i;
761 
762 	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
763 	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
764 			buf[FW_POS_STATE];
765 
766 	dev_dbg(&ts->client->dev,
767 		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
768 
769 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
770 		if (finger_state & 1) {
771 			unsigned int x, y, p, w;
772 			u8 *pos;
773 
774 			pos = &buf[FW_POS_XY + i * 3];
775 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
776 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
777 			p = buf[FW_POS_PRESSURE + i];
778 			w = buf[FW_POS_WIDTH + i];
779 
780 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
781 				i, x, y, p, w);
782 
783 			input_mt_slot(input, i);
784 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
785 			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
786 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
787 			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
788 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
789 
790 			n_fingers--;
791 		}
792 
793 		finger_state >>= 1;
794 	}
795 
796 	input_mt_sync_frame(input);
797 	input_sync(input);
798 }
799 
800 static u8 elants_i2c_calculate_checksum(u8 *buf)
801 {
802 	u8 checksum = 0;
803 	u8 i;
804 
805 	for (i = 0; i < FW_POS_CHECKSUM; i++)
806 		checksum += buf[i];
807 
808 	return checksum;
809 }
810 
811 static void elants_i2c_event(struct elants_data *ts, u8 *buf)
812 {
813 	u8 checksum = elants_i2c_calculate_checksum(buf);
814 
815 	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
816 		dev_warn(&ts->client->dev,
817 			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
818 			 __func__, buf[FW_POS_HEADER],
819 			 checksum, buf[FW_POS_CHECKSUM]);
820 	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
821 		dev_warn(&ts->client->dev,
822 			 "%s: unknown packet type: %02x\n",
823 			 __func__, buf[FW_POS_HEADER]);
824 	else
825 		elants_i2c_mt_event(ts, buf);
826 }
827 
828 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
829 {
830 	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
831 	struct elants_data *ts = _dev;
832 	struct i2c_client *client = ts->client;
833 	int report_count, report_len;
834 	int i;
835 	int len;
836 
837 	len = i2c_master_recv(client, ts->buf, sizeof(ts->buf));
838 	if (len < 0) {
839 		dev_err(&client->dev, "%s: failed to read data: %d\n",
840 			__func__, len);
841 		goto out;
842 	}
843 
844 	dev_dbg(&client->dev, "%s: packet %*ph\n",
845 		__func__, HEADER_SIZE, ts->buf);
846 
847 	switch (ts->state) {
848 	case ELAN_WAIT_RECALIBRATION:
849 		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
850 			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
851 			complete(&ts->cmd_done);
852 			ts->state = ELAN_STATE_NORMAL;
853 		}
854 		break;
855 
856 	case ELAN_WAIT_QUEUE_HEADER:
857 		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
858 			break;
859 
860 		ts->state = ELAN_STATE_NORMAL;
861 		/* fall through */
862 
863 	case ELAN_STATE_NORMAL:
864 
865 		switch (ts->buf[FW_HDR_TYPE]) {
866 		case CMD_HEADER_HELLO:
867 		case CMD_HEADER_RESP:
868 		case CMD_HEADER_REK:
869 			break;
870 
871 		case QUEUE_HEADER_WAIT:
872 			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
873 				dev_err(&client->dev,
874 					"invalid wait packet %*ph\n",
875 					HEADER_SIZE, ts->buf);
876 			} else {
877 				ts->state = ELAN_WAIT_QUEUE_HEADER;
878 				udelay(30);
879 			}
880 			break;
881 
882 		case QUEUE_HEADER_SINGLE:
883 			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
884 			break;
885 
886 		case QUEUE_HEADER_NORMAL:
887 			report_count = ts->buf[FW_HDR_COUNT];
888 			if (report_count > 3) {
889 				dev_err(&client->dev,
890 					"too large report count: %*ph\n",
891 					HEADER_SIZE, ts->buf);
892 				break;
893 			}
894 
895 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
896 			if (report_len != PACKET_SIZE) {
897 				dev_err(&client->dev,
898 					"mismatching report length: %*ph\n",
899 					HEADER_SIZE, ts->buf);
900 				break;
901 			}
902 
903 			for (i = 0; i < report_count; i++) {
904 				u8 *buf = ts->buf + HEADER_SIZE +
905 							i * PACKET_SIZE;
906 				elants_i2c_event(ts, buf);
907 			}
908 			break;
909 
910 		default:
911 			dev_err(&client->dev, "unknown packet %*ph\n",
912 				HEADER_SIZE, ts->buf);
913 			break;
914 		}
915 		break;
916 	}
917 
918 out:
919 	return IRQ_HANDLED;
920 }
921 
922 /*
923  * sysfs interface
924  */
925 static ssize_t calibrate_store(struct device *dev,
926 			       struct device_attribute *attr,
927 			      const char *buf, size_t count)
928 {
929 	struct i2c_client *client = to_i2c_client(dev);
930 	struct elants_data *ts = i2c_get_clientdata(client);
931 	int error;
932 
933 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
934 	if (error)
935 		return error;
936 
937 	error = elants_i2c_calibrate(ts);
938 
939 	mutex_unlock(&ts->sysfs_mutex);
940 	return error ?: count;
941 }
942 
943 static ssize_t write_update_fw(struct device *dev,
944 			       struct device_attribute *attr,
945 			       const char *buf, size_t count)
946 {
947 	struct i2c_client *client = to_i2c_client(dev);
948 	struct elants_data *ts = i2c_get_clientdata(client);
949 	int error;
950 
951 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
952 	if (error)
953 		return error;
954 
955 	error = elants_i2c_fw_update(ts);
956 	dev_dbg(dev, "firmware update result: %d\n", error);
957 
958 	mutex_unlock(&ts->sysfs_mutex);
959 	return error ?: count;
960 }
961 
962 static ssize_t show_iap_mode(struct device *dev,
963 			     struct device_attribute *attr, char *buf)
964 {
965 	struct i2c_client *client = to_i2c_client(dev);
966 	struct elants_data *ts = i2c_get_clientdata(client);
967 
968 	return sprintf(buf, "%s\n",
969 		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
970 				"Normal" : "Recovery");
971 }
972 
973 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, calibrate_store);
974 static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
975 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
976 
977 struct elants_version_attribute {
978 	struct device_attribute dattr;
979 	size_t field_offset;
980 	size_t field_size;
981 };
982 
983 #define __ELANTS_FIELD_SIZE(_field)					\
984 	sizeof(((struct elants_data *)NULL)->_field)
985 #define __ELANTS_VERIFY_SIZE(_field)					\
986 	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
987 	 __ELANTS_FIELD_SIZE(_field))
988 #define ELANTS_VERSION_ATTR(_field)					\
989 	struct elants_version_attribute elants_ver_attr_##_field = {	\
990 		.dattr = __ATTR(_field, S_IRUGO,			\
991 				elants_version_attribute_show, NULL),	\
992 		.field_offset = offsetof(struct elants_data, _field),	\
993 		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
994 	}
995 
996 static ssize_t elants_version_attribute_show(struct device *dev,
997 					     struct device_attribute *dattr,
998 					     char *buf)
999 {
1000 	struct i2c_client *client = to_i2c_client(dev);
1001 	struct elants_data *ts = i2c_get_clientdata(client);
1002 	struct elants_version_attribute *attr =
1003 		container_of(dattr, struct elants_version_attribute, dattr);
1004 	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1005 	unsigned int fmt_size;
1006 	unsigned int val;
1007 
1008 	if (attr->field_size == 1) {
1009 		val = *field;
1010 		fmt_size = 2; /* 2 HEX digits */
1011 	} else {
1012 		val = *(u16 *)field;
1013 		fmt_size = 4; /* 4 HEX digits */
1014 	}
1015 
1016 	return sprintf(buf, "%0*x\n", fmt_size, val);
1017 }
1018 
1019 static ELANTS_VERSION_ATTR(fw_version);
1020 static ELANTS_VERSION_ATTR(hw_version);
1021 static ELANTS_VERSION_ATTR(test_version);
1022 static ELANTS_VERSION_ATTR(solution_version);
1023 static ELANTS_VERSION_ATTR(bc_version);
1024 static ELANTS_VERSION_ATTR(iap_version);
1025 
1026 static struct attribute *elants_attributes[] = {
1027 	&dev_attr_calibrate.attr,
1028 	&dev_attr_update_fw.attr,
1029 	&dev_attr_iap_mode.attr,
1030 
1031 	&elants_ver_attr_fw_version.dattr.attr,
1032 	&elants_ver_attr_hw_version.dattr.attr,
1033 	&elants_ver_attr_test_version.dattr.attr,
1034 	&elants_ver_attr_solution_version.dattr.attr,
1035 	&elants_ver_attr_bc_version.dattr.attr,
1036 	&elants_ver_attr_iap_version.dattr.attr,
1037 	NULL
1038 };
1039 
1040 static struct attribute_group elants_attribute_group = {
1041 	.attrs = elants_attributes,
1042 };
1043 
1044 static void elants_i2c_remove_sysfs_group(void *_data)
1045 {
1046 	struct elants_data *ts = _data;
1047 
1048 	sysfs_remove_group(&ts->client->dev.kobj, &elants_attribute_group);
1049 }
1050 
1051 static int elants_i2c_probe(struct i2c_client *client,
1052 			    const struct i2c_device_id *id)
1053 {
1054 	union i2c_smbus_data dummy;
1055 	struct elants_data *ts;
1056 	unsigned long irqflags;
1057 	int error;
1058 
1059 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1060 		dev_err(&client->dev,
1061 			"%s: i2c check functionality error\n", DEVICE_NAME);
1062 		return -ENXIO;
1063 	}
1064 
1065 	/* Make sure there is something at this address */
1066 	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1067 			I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1068 		dev_err(&client->dev, "nothing at this address\n");
1069 		return -ENXIO;
1070 	}
1071 
1072 	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1073 	if (!ts)
1074 		return -ENOMEM;
1075 
1076 	mutex_init(&ts->sysfs_mutex);
1077 	init_completion(&ts->cmd_done);
1078 
1079 	ts->client = client;
1080 	i2c_set_clientdata(client, ts);
1081 
1082 	error = elants_i2c_initialize(ts);
1083 	if (error) {
1084 		dev_err(&client->dev, "failed to initialize: %d\n", error);
1085 		return error;
1086 	}
1087 
1088 	ts->input = devm_input_allocate_device(&client->dev);
1089 	if (!ts->input) {
1090 		dev_err(&client->dev, "Failed to allocate input device\n");
1091 		return -ENOMEM;
1092 	}
1093 
1094 	ts->input->name = "Elan Touchscreen";
1095 	ts->input->id.bustype = BUS_I2C;
1096 
1097 	__set_bit(BTN_TOUCH, ts->input->keybit);
1098 	__set_bit(EV_ABS, ts->input->evbit);
1099 	__set_bit(EV_KEY, ts->input->evbit);
1100 
1101 	/* Single touch input params setup */
1102 	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1103 	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1104 	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1105 	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1106 	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1107 
1108 	/* Multitouch input params setup */
1109 	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1110 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1111 	if (error) {
1112 		dev_err(&client->dev,
1113 			"failed to initialize MT slots: %d\n", error);
1114 		return error;
1115 	}
1116 
1117 	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1118 	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1119 	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1120 	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1121 	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1122 	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1123 
1124 	input_set_drvdata(ts->input, ts);
1125 
1126 	error = input_register_device(ts->input);
1127 	if (error) {
1128 		dev_err(&client->dev,
1129 			"unable to register input device: %d\n", error);
1130 		return error;
1131 	}
1132 
1133 	/*
1134 	 * Systems using device tree should set up interrupt via DTS,
1135 	 * the rest will use the default falling edge interrupts.
1136 	 */
1137 	irqflags = client->dev.of_node ? 0 : IRQF_TRIGGER_FALLING;
1138 
1139 	error = devm_request_threaded_irq(&client->dev, client->irq,
1140 					  NULL, elants_i2c_irq,
1141 					  irqflags | IRQF_ONESHOT,
1142 					  client->name, ts);
1143 	if (error) {
1144 		dev_err(&client->dev, "Failed to register interrupt\n");
1145 		return error;
1146 	}
1147 
1148 	/*
1149 	 * Systems using device tree should set up wakeup via DTS,
1150 	 * the rest will configure device as wakeup source by default.
1151 	 */
1152 	if (!client->dev.of_node)
1153 		device_init_wakeup(&client->dev, true);
1154 
1155 	error = sysfs_create_group(&client->dev.kobj, &elants_attribute_group);
1156 	if (error) {
1157 		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1158 			error);
1159 		return error;
1160 	}
1161 
1162 	error = devm_add_action(&client->dev,
1163 				elants_i2c_remove_sysfs_group, ts);
1164 	if (error) {
1165 		elants_i2c_remove_sysfs_group(ts);
1166 		dev_err(&client->dev,
1167 			"Failed to add sysfs cleanup action: %d\n",
1168 			error);
1169 		return error;
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 static int __maybe_unused elants_i2c_suspend(struct device *dev)
1176 {
1177 	struct i2c_client *client = to_i2c_client(dev);
1178 	struct elants_data *ts = i2c_get_clientdata(client);
1179 	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1180 	int retry_cnt;
1181 	int error;
1182 
1183 	/* Command not support in IAP recovery mode */
1184 	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1185 		return -EBUSY;
1186 
1187 	disable_irq(client->irq);
1188 
1189 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1190 		error = elants_i2c_send(client, set_sleep_cmd,
1191 					sizeof(set_sleep_cmd));
1192 		if (!error)
1193 			break;
1194 
1195 		dev_err(&client->dev, "suspend command failed: %d\n", error);
1196 	}
1197 
1198 	if (device_may_wakeup(dev))
1199 		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1200 
1201 	return 0;
1202 }
1203 
1204 static int __maybe_unused elants_i2c_resume(struct device *dev)
1205 {
1206 	struct i2c_client *client = to_i2c_client(dev);
1207 	struct elants_data *ts = i2c_get_clientdata(client);
1208 	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1209 	int retry_cnt;
1210 	int error;
1211 
1212 	if (device_may_wakeup(dev) && ts->wake_irq_enabled)
1213 		disable_irq_wake(client->irq);
1214 
1215 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1216 		error = elants_i2c_send(client, set_active_cmd,
1217 					sizeof(set_active_cmd));
1218 		if (!error)
1219 			break;
1220 
1221 		dev_err(&client->dev, "resume command failed: %d\n", error);
1222 	}
1223 
1224 	ts->state = ELAN_STATE_NORMAL;
1225 	enable_irq(client->irq);
1226 
1227 	return 0;
1228 }
1229 
1230 static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1231 			 elants_i2c_suspend, elants_i2c_resume);
1232 
1233 static const struct i2c_device_id elants_i2c_id[] = {
1234 	{ DEVICE_NAME, 0 },
1235 	{ }
1236 };
1237 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1238 
1239 #ifdef CONFIG_ACPI
1240 static const struct acpi_device_id elants_acpi_id[] = {
1241 	{ "ELAN0001", 0 },
1242 	{ }
1243 };
1244 MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1245 #endif
1246 
1247 #ifdef CONFIG_OF
1248 static const struct of_device_id elants_of_match[] = {
1249 	{ .compatible = "elan,ekth3500" },
1250 	{ /* sentinel */ }
1251 };
1252 MODULE_DEVICE_TABLE(of, elants_of_match);
1253 #endif
1254 
1255 static struct i2c_driver elants_i2c_driver = {
1256 	.probe = elants_i2c_probe,
1257 	.id_table = elants_i2c_id,
1258 	.driver = {
1259 		.name = DEVICE_NAME,
1260 		.owner = THIS_MODULE,
1261 		.pm = &elants_i2c_pm_ops,
1262 		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1263 		.of_match_table = of_match_ptr(elants_of_match),
1264 	},
1265 };
1266 module_i2c_driver(elants_i2c_driver);
1267 
1268 MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1269 MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1270 MODULE_VERSION(DRV_VERSION);
1271 MODULE_LICENSE("GPL");
1272