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/slab.h>
37 #include <linux/firmware.h>
38 #include <linux/input/mt.h>
39 #include <linux/acpi.h>
40 #include <linux/of.h>
41 #include <asm/unaligned.h>
42 
43 /* Device, Driver information */
44 #define DEVICE_NAME	"elants_i2c"
45 #define DRV_VERSION	"1.0.9"
46 
47 /* Convert from rows or columns into resolution */
48 #define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
49 
50 /* FW header data */
51 #define HEADER_SIZE		4
52 #define FW_HDR_TYPE		0
53 #define FW_HDR_COUNT		1
54 #define FW_HDR_LENGTH		2
55 
56 /* Buffer mode Queue Header information */
57 #define QUEUE_HEADER_SINGLE	0x62
58 #define QUEUE_HEADER_NORMAL	0X63
59 #define QUEUE_HEADER_WAIT	0x64
60 
61 /* Command header definition */
62 #define CMD_HEADER_WRITE	0x54
63 #define CMD_HEADER_READ		0x53
64 #define CMD_HEADER_6B_READ	0x5B
65 #define CMD_HEADER_RESP		0x52
66 #define CMD_HEADER_6B_RESP	0x9B
67 #define CMD_HEADER_HELLO	0x55
68 #define CMD_HEADER_REK		0x66
69 
70 /* FW position data */
71 #define PACKET_SIZE		55
72 #define MAX_CONTACT_NUM		10
73 #define FW_POS_HEADER		0
74 #define FW_POS_STATE		1
75 #define FW_POS_TOTAL		2
76 #define FW_POS_XY		3
77 #define FW_POS_CHECKSUM		34
78 #define FW_POS_WIDTH		35
79 #define FW_POS_PRESSURE		45
80 
81 #define HEADER_REPORT_10_FINGER	0x62
82 
83 /* Header (4 bytes) plus 3 fill 10-finger packets */
84 #define MAX_PACKET_SIZE		169
85 
86 #define BOOT_TIME_DELAY_MS	50
87 
88 /* FW read command, 0x53 0x?? 0x0, 0x01 */
89 #define E_ELAN_INFO_FW_VER	0x00
90 #define E_ELAN_INFO_BC_VER	0x10
91 #define E_ELAN_INFO_TEST_VER	0xE0
92 #define E_ELAN_INFO_FW_ID	0xF0
93 #define E_INFO_OSR		0xD6
94 #define E_INFO_PHY_SCAN		0xD7
95 #define E_INFO_PHY_DRIVER	0xD8
96 
97 #define MAX_RETRIES		3
98 #define MAX_FW_UPDATE_RETRIES	30
99 
100 #define ELAN_FW_PAGESIZE	132
101 #define ELAN_FW_FILENAME	"elants_i2c.bin"
102 
103 /* calibration timeout definition */
104 #define ELAN_CALI_TIMEOUT_MSEC	10000
105 
106 enum elants_state {
107 	ELAN_STATE_NORMAL,
108 	ELAN_WAIT_QUEUE_HEADER,
109 	ELAN_WAIT_RECALIBRATION,
110 };
111 
112 enum elants_iap_mode {
113 	ELAN_IAP_OPERATIONAL,
114 	ELAN_IAP_RECOVERY,
115 };
116 
117 /* struct elants_data - represents state of Elan touchscreen device */
118 struct elants_data {
119 	struct i2c_client *client;
120 	struct input_dev *input;
121 
122 	u16 fw_version;
123 	u8 test_version;
124 	u8 solution_version;
125 	u8 bc_version;
126 	u8 iap_version;
127 	u16 hw_version;
128 	unsigned int x_res;	/* resolution in units/mm */
129 	unsigned int y_res;
130 	unsigned int x_max;
131 	unsigned int y_max;
132 
133 	enum elants_state state;
134 	enum elants_iap_mode iap_mode;
135 
136 	/* Guards against concurrent access to the device via sysfs */
137 	struct mutex sysfs_mutex;
138 
139 	u8 cmd_resp[HEADER_SIZE];
140 	struct completion cmd_done;
141 
142 	u8 buf[MAX_PACKET_SIZE];
143 
144 	bool wake_irq_enabled;
145 };
146 
147 static int elants_i2c_send(struct i2c_client *client,
148 			   const void *data, size_t size)
149 {
150 	int ret;
151 
152 	ret = i2c_master_send(client, data, size);
153 	if (ret == size)
154 		return 0;
155 
156 	if (ret >= 0)
157 		ret = -EIO;
158 
159 	dev_err(&client->dev, "%s failed (%*ph): %d\n",
160 		__func__, (int)size, data, ret);
161 
162 	return ret;
163 }
164 
165 static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
166 {
167 	int ret;
168 
169 	ret = i2c_master_recv(client, data, size);
170 	if (ret == size)
171 		return 0;
172 
173 	if (ret >= 0)
174 		ret = -EIO;
175 
176 	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
177 
178 	return ret;
179 }
180 
181 static int elants_i2c_execute_command(struct i2c_client *client,
182 				      const u8 *cmd, size_t cmd_size,
183 				      u8 *resp, size_t resp_size)
184 {
185 	struct i2c_msg msgs[2];
186 	int ret;
187 	u8 expected_response;
188 
189 	switch (cmd[0]) {
190 	case CMD_HEADER_READ:
191 		expected_response = CMD_HEADER_RESP;
192 		break;
193 
194 	case CMD_HEADER_6B_READ:
195 		expected_response = CMD_HEADER_6B_RESP;
196 		break;
197 
198 	default:
199 		dev_err(&client->dev, "%s: invalid command %*ph\n",
200 			__func__, (int)cmd_size, cmd);
201 		return -EINVAL;
202 	}
203 
204 	msgs[0].addr = client->addr;
205 	msgs[0].flags = client->flags & I2C_M_TEN;
206 	msgs[0].len = cmd_size;
207 	msgs[0].buf = (u8 *)cmd;
208 
209 	msgs[1].addr = client->addr;
210 	msgs[1].flags = client->flags & I2C_M_TEN;
211 	msgs[1].flags |= I2C_M_RD;
212 	msgs[1].len = resp_size;
213 	msgs[1].buf = resp;
214 
215 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
216 	if (ret < 0)
217 		return ret;
218 
219 	if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
220 		return -EIO;
221 
222 	return 0;
223 }
224 
225 static int elants_i2c_calibrate(struct elants_data *ts)
226 {
227 	struct i2c_client *client = ts->client;
228 	int ret, error;
229 	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
230 	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
231 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
232 
233 	disable_irq(client->irq);
234 
235 	ts->state = ELAN_WAIT_RECALIBRATION;
236 	reinit_completion(&ts->cmd_done);
237 
238 	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
239 	elants_i2c_send(client, rek, sizeof(rek));
240 
241 	enable_irq(client->irq);
242 
243 	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
244 				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
245 
246 	ts->state = ELAN_STATE_NORMAL;
247 
248 	if (ret <= 0) {
249 		error = ret < 0 ? ret : -ETIMEDOUT;
250 		dev_err(&client->dev,
251 			"error while waiting for calibration to complete: %d\n",
252 			error);
253 		return error;
254 	}
255 
256 	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
257 		dev_err(&client->dev,
258 			"unexpected calibration response: %*ph\n",
259 			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
260 		return -EINVAL;
261 	}
262 
263 	return 0;
264 }
265 
266 static int elants_i2c_sw_reset(struct i2c_client *client)
267 {
268 	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
269 	int error;
270 
271 	error = elants_i2c_send(client, soft_rst_cmd,
272 				sizeof(soft_rst_cmd));
273 	if (error) {
274 		dev_err(&client->dev, "software reset failed: %d\n", error);
275 		return error;
276 	}
277 
278 	/*
279 	 * We should wait at least 10 msec (but no more than 40) before
280 	 * sending fastboot or IAP command to the device.
281 	 */
282 	msleep(30);
283 
284 	return 0;
285 }
286 
287 static u16 elants_i2c_parse_version(u8 *buf)
288 {
289 	return get_unaligned_be32(buf) >> 4;
290 }
291 
292 static int elants_i2c_query_fw_id(struct elants_data *ts)
293 {
294 	struct i2c_client *client = ts->client;
295 	int error, retry_cnt;
296 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
297 	u8 resp[HEADER_SIZE];
298 
299 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
300 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
301 						   resp, sizeof(resp));
302 		if (!error) {
303 			ts->hw_version = elants_i2c_parse_version(resp);
304 			if (ts->hw_version != 0xffff)
305 				return 0;
306 		}
307 
308 		dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
309 			error, (int)sizeof(resp), resp);
310 	}
311 
312 	dev_err(&client->dev,
313 		"Failed to read fw id or fw id is invalid\n");
314 
315 	return -EINVAL;
316 }
317 
318 static int elants_i2c_query_fw_version(struct elants_data *ts)
319 {
320 	struct i2c_client *client = ts->client;
321 	int error, retry_cnt;
322 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
323 	u8 resp[HEADER_SIZE];
324 
325 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
326 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
327 						   resp, sizeof(resp));
328 		if (!error) {
329 			ts->fw_version = elants_i2c_parse_version(resp);
330 			if (ts->fw_version != 0x0000 &&
331 			    ts->fw_version != 0xffff)
332 				return 0;
333 		}
334 
335 		dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
336 			error, (int)sizeof(resp), resp);
337 	}
338 
339 	dev_err(&client->dev,
340 		"Failed to read fw version or fw version is invalid\n");
341 
342 	return -EINVAL;
343 }
344 
345 static int elants_i2c_query_test_version(struct elants_data *ts)
346 {
347 	struct i2c_client *client = ts->client;
348 	int error, retry_cnt;
349 	u16 version;
350 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
351 	u8 resp[HEADER_SIZE];
352 
353 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
354 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
355 						   resp, sizeof(resp));
356 		if (!error) {
357 			version = elants_i2c_parse_version(resp);
358 			ts->test_version = version >> 8;
359 			ts->solution_version = version & 0xff;
360 
361 			return 0;
362 		}
363 
364 		dev_dbg(&client->dev,
365 			"read test version error rc=%d, buf=%*phC\n",
366 			error, (int)sizeof(resp), resp);
367 	}
368 
369 	dev_err(&client->dev, "Failed to read test version\n");
370 
371 	return -EINVAL;
372 }
373 
374 static int elants_i2c_query_bc_version(struct elants_data *ts)
375 {
376 	struct i2c_client *client = ts->client;
377 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
378 	u8 resp[HEADER_SIZE];
379 	u16 version;
380 	int error;
381 
382 	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
383 					   resp, sizeof(resp));
384 	if (error) {
385 		dev_err(&client->dev,
386 			"read BC version error=%d, buf=%*phC\n",
387 			error, (int)sizeof(resp), resp);
388 		return error;
389 	}
390 
391 	version = elants_i2c_parse_version(resp);
392 	ts->bc_version = version >> 8;
393 	ts->iap_version = version & 0xff;
394 
395 	return 0;
396 }
397 
398 static int elants_i2c_query_ts_info(struct elants_data *ts)
399 {
400 	struct i2c_client *client = ts->client;
401 	int error;
402 	u8 resp[17];
403 	u16 phy_x, phy_y, rows, cols, osr;
404 	const u8 get_resolution_cmd[] = {
405 		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
406 	};
407 	const u8 get_osr_cmd[] = {
408 		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
409 	};
410 	const u8 get_physical_scan_cmd[] = {
411 		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
412 	};
413 	const u8 get_physical_drive_cmd[] = {
414 		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
415 	};
416 
417 	/* Get trace number */
418 	error = elants_i2c_execute_command(client,
419 					   get_resolution_cmd,
420 					   sizeof(get_resolution_cmd),
421 					   resp, sizeof(resp));
422 	if (error) {
423 		dev_err(&client->dev, "get resolution command failed: %d\n",
424 			error);
425 		return error;
426 	}
427 
428 	rows = resp[2] + resp[6] + resp[10];
429 	cols = resp[3] + resp[7] + resp[11];
430 
431 	/* Process mm_to_pixel information */
432 	error = elants_i2c_execute_command(client,
433 					   get_osr_cmd, sizeof(get_osr_cmd),
434 					   resp, sizeof(resp));
435 	if (error) {
436 		dev_err(&client->dev, "get osr command failed: %d\n",
437 			error);
438 		return error;
439 	}
440 
441 	osr = resp[3];
442 
443 	error = elants_i2c_execute_command(client,
444 					   get_physical_scan_cmd,
445 					   sizeof(get_physical_scan_cmd),
446 					   resp, sizeof(resp));
447 	if (error) {
448 		dev_err(&client->dev, "get physical scan command failed: %d\n",
449 			error);
450 		return error;
451 	}
452 
453 	phy_x = get_unaligned_be16(&resp[2]);
454 
455 	error = elants_i2c_execute_command(client,
456 					   get_physical_drive_cmd,
457 					   sizeof(get_physical_drive_cmd),
458 					   resp, sizeof(resp));
459 	if (error) {
460 		dev_err(&client->dev, "get physical drive command failed: %d\n",
461 			error);
462 		return error;
463 	}
464 
465 	phy_y = get_unaligned_be16(&resp[2]);
466 
467 	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
468 
469 	if (rows == 0 || cols == 0 || osr == 0) {
470 		dev_warn(&client->dev,
471 			 "invalid trace number data: %d, %d, %d\n",
472 			 rows, cols, osr);
473 	} else {
474 		/* translate trace number to TS resolution */
475 		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
476 		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
477 		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
478 		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
479 	}
480 
481 	return 0;
482 }
483 
484 static int elants_i2c_fastboot(struct i2c_client *client)
485 {
486 	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
487 	int error;
488 
489 	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
490 	if (error) {
491 		dev_err(&client->dev, "boot failed: %d\n", error);
492 		return error;
493 	}
494 
495 	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
496 	return 0;
497 }
498 
499 static int elants_i2c_initialize(struct elants_data *ts)
500 {
501 	struct i2c_client *client = ts->client;
502 	int error, retry_cnt;
503 	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
504 	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
505 	u8 buf[HEADER_SIZE];
506 
507 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
508 		error = elants_i2c_sw_reset(client);
509 		if (error) {
510 			/* Continue initializing if it's the last try */
511 			if (retry_cnt < MAX_RETRIES - 1)
512 				continue;
513 		}
514 
515 		error = elants_i2c_fastboot(client);
516 		if (error) {
517 			/* Continue initializing if it's the last try */
518 			if (retry_cnt < MAX_RETRIES - 1)
519 				continue;
520 		}
521 
522 		/* Wait for Hello packet */
523 		msleep(BOOT_TIME_DELAY_MS);
524 
525 		error = elants_i2c_read(client, buf, sizeof(buf));
526 		if (error) {
527 			dev_err(&client->dev,
528 				"failed to read 'hello' packet: %d\n", error);
529 		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
530 			ts->iap_mode = ELAN_IAP_OPERATIONAL;
531 			break;
532 		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
533 			/*
534 			 * Setting error code will mark device
535 			 * in recovery mode below.
536 			 */
537 			error = -EIO;
538 			break;
539 		} else {
540 			error = -EINVAL;
541 			dev_err(&client->dev,
542 				"invalid 'hello' packet: %*ph\n",
543 				(int)sizeof(buf), buf);
544 		}
545 	}
546 
547 	if (!error)
548 		error = elants_i2c_query_fw_id(ts);
549 	if (!error)
550 		error = elants_i2c_query_fw_version(ts);
551 
552 	if (error) {
553 		ts->iap_mode = ELAN_IAP_RECOVERY;
554 	} else {
555 		elants_i2c_query_test_version(ts);
556 		elants_i2c_query_bc_version(ts);
557 		elants_i2c_query_ts_info(ts);
558 	}
559 
560 	return 0;
561 }
562 
563 /*
564  * Firmware update interface.
565  */
566 
567 static int elants_i2c_fw_write_page(struct i2c_client *client,
568 				    const void *page)
569 {
570 	const u8 ack_ok[] = { 0xaa, 0xaa };
571 	u8 buf[2];
572 	int retry;
573 	int error;
574 
575 	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
576 		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
577 		if (error) {
578 			dev_err(&client->dev,
579 				"IAP Write Page failed: %d\n", error);
580 			continue;
581 		}
582 
583 		error = elants_i2c_read(client, buf, 2);
584 		if (error) {
585 			dev_err(&client->dev,
586 				"IAP Ack read failed: %d\n", error);
587 			return error;
588 		}
589 
590 		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
591 			return 0;
592 
593 		error = -EIO;
594 		dev_err(&client->dev,
595 			"IAP Get Ack Error [%02x:%02x]\n",
596 			buf[0], buf[1]);
597 	}
598 
599 	return error;
600 }
601 
602 static int elants_i2c_do_update_firmware(struct i2c_client *client,
603 					 const struct firmware *fw,
604 					 bool force)
605 {
606 	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
607 	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
608 	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
609 	u8 buf[HEADER_SIZE];
610 	u16 send_id;
611 	int page, n_fw_pages;
612 	int error;
613 
614 	/* Recovery mode detection! */
615 	if (force) {
616 		dev_dbg(&client->dev, "Recovery mode procedure\n");
617 		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
618 	} else {
619 		/* Start IAP Procedure */
620 		dev_dbg(&client->dev, "Normal IAP procedure\n");
621 		elants_i2c_sw_reset(client);
622 
623 		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
624 	}
625 
626 	if (error) {
627 		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
628 		return error;
629 	}
630 
631 	msleep(20);
632 
633 	/* check IAP state */
634 	error = elants_i2c_read(client, buf, 4);
635 	if (error) {
636 		dev_err(&client->dev,
637 			"failed to read IAP acknowledgement: %d\n",
638 			error);
639 		return error;
640 	}
641 
642 	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
643 		dev_err(&client->dev,
644 			"failed to enter IAP: %*ph (expected %*ph)\n",
645 			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
646 		return -EIO;
647 	}
648 
649 	dev_info(&client->dev, "successfully entered IAP mode");
650 
651 	send_id = client->addr;
652 	error = elants_i2c_send(client, &send_id, 1);
653 	if (error) {
654 		dev_err(&client->dev, "sending dummy byte failed: %d\n",
655 			error);
656 		return error;
657 	}
658 
659 	/* Clear the last page of Master */
660 	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
661 	if (error) {
662 		dev_err(&client->dev, "clearing of the last page failed: %d\n",
663 			error);
664 		return error;
665 	}
666 
667 	error = elants_i2c_read(client, buf, 2);
668 	if (error) {
669 		dev_err(&client->dev,
670 			"failed to read ACK for clearing the last page: %d\n",
671 			error);
672 		return error;
673 	}
674 
675 	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
676 	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
677 
678 	for (page = 0; page < n_fw_pages; page++) {
679 		error = elants_i2c_fw_write_page(client,
680 					fw->data + page * ELAN_FW_PAGESIZE);
681 		if (error) {
682 			dev_err(&client->dev,
683 				"failed to write FW page %d: %d\n",
684 				page, error);
685 			return error;
686 		}
687 	}
688 
689 	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
690 	msleep(300);
691 
692 	dev_info(&client->dev, "firmware update completed\n");
693 	return 0;
694 }
695 
696 static int elants_i2c_fw_update(struct elants_data *ts)
697 {
698 	struct i2c_client *client = ts->client;
699 	const struct firmware *fw;
700 	int error;
701 
702 	error = request_firmware(&fw, ELAN_FW_FILENAME, &client->dev);
703 	if (error) {
704 		dev_err(&client->dev, "failed to request firmware %s: %d\n",
705 			ELAN_FW_FILENAME, error);
706 		return error;
707 	}
708 
709 	if (fw->size % ELAN_FW_PAGESIZE) {
710 		dev_err(&client->dev, "invalid firmware length: %zu\n",
711 			fw->size);
712 		error = -EINVAL;
713 		goto out;
714 	}
715 
716 	disable_irq(client->irq);
717 
718 	error = elants_i2c_do_update_firmware(client, fw,
719 					ts->iap_mode == ELAN_IAP_RECOVERY);
720 	if (error) {
721 		dev_err(&client->dev, "firmware update failed: %d\n", error);
722 		ts->iap_mode = ELAN_IAP_RECOVERY;
723 		goto out_enable_irq;
724 	}
725 
726 	error = elants_i2c_initialize(ts);
727 	if (error) {
728 		dev_err(&client->dev,
729 			"failed to initialize device after firmware update: %d\n",
730 			error);
731 		ts->iap_mode = ELAN_IAP_RECOVERY;
732 		goto out_enable_irq;
733 	}
734 
735 	ts->iap_mode = ELAN_IAP_OPERATIONAL;
736 
737 out_enable_irq:
738 	ts->state = ELAN_STATE_NORMAL;
739 	enable_irq(client->irq);
740 	msleep(100);
741 
742 	if (!error)
743 		elants_i2c_calibrate(ts);
744 out:
745 	release_firmware(fw);
746 	return error;
747 }
748 
749 /*
750  * Event reporting.
751  */
752 
753 static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
754 {
755 	struct input_dev *input = ts->input;
756 	unsigned int n_fingers;
757 	u16 finger_state;
758 	int i;
759 
760 	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
761 	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
762 			buf[FW_POS_STATE];
763 
764 	dev_dbg(&ts->client->dev,
765 		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
766 
767 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
768 		if (finger_state & 1) {
769 			unsigned int x, y, p, w;
770 			u8 *pos;
771 
772 			pos = &buf[FW_POS_XY + i * 3];
773 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
774 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
775 			p = buf[FW_POS_PRESSURE + i];
776 			w = buf[FW_POS_WIDTH + i];
777 
778 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
779 				i, x, y, p, w);
780 
781 			input_mt_slot(input, i);
782 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
783 			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
784 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
785 			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
786 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
787 
788 			n_fingers--;
789 		}
790 
791 		finger_state >>= 1;
792 	}
793 
794 	input_mt_sync_frame(input);
795 	input_sync(input);
796 }
797 
798 static u8 elants_i2c_calculate_checksum(u8 *buf)
799 {
800 	u8 checksum = 0;
801 	u8 i;
802 
803 	for (i = 0; i < FW_POS_CHECKSUM; i++)
804 		checksum += buf[i];
805 
806 	return checksum;
807 }
808 
809 static void elants_i2c_event(struct elants_data *ts, u8 *buf)
810 {
811 	u8 checksum = elants_i2c_calculate_checksum(buf);
812 
813 	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
814 		dev_warn(&ts->client->dev,
815 			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
816 			 __func__, buf[FW_POS_HEADER],
817 			 checksum, buf[FW_POS_CHECKSUM]);
818 	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
819 		dev_warn(&ts->client->dev,
820 			 "%s: unknown packet type: %02x\n",
821 			 __func__, buf[FW_POS_HEADER]);
822 	else
823 		elants_i2c_mt_event(ts, buf);
824 }
825 
826 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
827 {
828 	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
829 	struct elants_data *ts = _dev;
830 	struct i2c_client *client = ts->client;
831 	int report_count, report_len;
832 	int i;
833 	int len;
834 
835 	len = i2c_master_recv(client, ts->buf, sizeof(ts->buf));
836 	if (len < 0) {
837 		dev_err(&client->dev, "%s: failed to read data: %d\n",
838 			__func__, len);
839 		goto out;
840 	}
841 
842 	dev_dbg(&client->dev, "%s: packet %*ph\n",
843 		__func__, HEADER_SIZE, ts->buf);
844 
845 	switch (ts->state) {
846 	case ELAN_WAIT_RECALIBRATION:
847 		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
848 			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
849 			complete(&ts->cmd_done);
850 			ts->state = ELAN_STATE_NORMAL;
851 		}
852 		break;
853 
854 	case ELAN_WAIT_QUEUE_HEADER:
855 		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
856 			break;
857 
858 		ts->state = ELAN_STATE_NORMAL;
859 		/* fall through */
860 
861 	case ELAN_STATE_NORMAL:
862 
863 		switch (ts->buf[FW_HDR_TYPE]) {
864 		case CMD_HEADER_HELLO:
865 		case CMD_HEADER_RESP:
866 		case CMD_HEADER_REK:
867 			break;
868 
869 		case QUEUE_HEADER_WAIT:
870 			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
871 				dev_err(&client->dev,
872 					"invalid wait packet %*ph\n",
873 					HEADER_SIZE, ts->buf);
874 			} else {
875 				ts->state = ELAN_WAIT_QUEUE_HEADER;
876 				udelay(30);
877 			}
878 			break;
879 
880 		case QUEUE_HEADER_SINGLE:
881 			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
882 			break;
883 
884 		case QUEUE_HEADER_NORMAL:
885 			report_count = ts->buf[FW_HDR_COUNT];
886 			if (report_count > 3) {
887 				dev_err(&client->dev,
888 					"too large report count: %*ph\n",
889 					HEADER_SIZE, ts->buf);
890 				break;
891 			}
892 
893 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
894 			if (report_len != PACKET_SIZE) {
895 				dev_err(&client->dev,
896 					"mismatching report length: %*ph\n",
897 					HEADER_SIZE, ts->buf);
898 				break;
899 			}
900 
901 			for (i = 0; i < report_count; i++) {
902 				u8 *buf = ts->buf + HEADER_SIZE +
903 							i * PACKET_SIZE;
904 				elants_i2c_event(ts, buf);
905 			}
906 			break;
907 
908 		default:
909 			dev_err(&client->dev, "unknown packet %*ph\n",
910 				HEADER_SIZE, ts->buf);
911 			break;
912 		}
913 		break;
914 	}
915 
916 out:
917 	return IRQ_HANDLED;
918 }
919 
920 /*
921  * sysfs interface
922  */
923 static ssize_t calibrate_store(struct device *dev,
924 			       struct device_attribute *attr,
925 			      const char *buf, size_t count)
926 {
927 	struct i2c_client *client = to_i2c_client(dev);
928 	struct elants_data *ts = i2c_get_clientdata(client);
929 	int error;
930 
931 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
932 	if (error)
933 		return error;
934 
935 	error = elants_i2c_calibrate(ts);
936 
937 	mutex_unlock(&ts->sysfs_mutex);
938 	return error ?: count;
939 }
940 
941 static ssize_t write_update_fw(struct device *dev,
942 			       struct device_attribute *attr,
943 			       const char *buf, size_t count)
944 {
945 	struct i2c_client *client = to_i2c_client(dev);
946 	struct elants_data *ts = i2c_get_clientdata(client);
947 	int error;
948 
949 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
950 	if (error)
951 		return error;
952 
953 	error = elants_i2c_fw_update(ts);
954 	dev_dbg(dev, "firmware update result: %d\n", error);
955 
956 	mutex_unlock(&ts->sysfs_mutex);
957 	return error ?: count;
958 }
959 
960 static ssize_t show_iap_mode(struct device *dev,
961 			     struct device_attribute *attr, char *buf)
962 {
963 	struct i2c_client *client = to_i2c_client(dev);
964 	struct elants_data *ts = i2c_get_clientdata(client);
965 
966 	return sprintf(buf, "%s\n",
967 		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
968 				"Normal" : "Recovery");
969 }
970 
971 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, calibrate_store);
972 static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
973 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
974 
975 struct elants_version_attribute {
976 	struct device_attribute dattr;
977 	size_t field_offset;
978 	size_t field_size;
979 };
980 
981 #define __ELANTS_FIELD_SIZE(_field)					\
982 	sizeof(((struct elants_data *)NULL)->_field)
983 #define __ELANTS_VERIFY_SIZE(_field)					\
984 	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
985 	 __ELANTS_FIELD_SIZE(_field))
986 #define ELANTS_VERSION_ATTR(_field)					\
987 	struct elants_version_attribute elants_ver_attr_##_field = {	\
988 		.dattr = __ATTR(_field, S_IRUGO,			\
989 				elants_version_attribute_show, NULL),	\
990 		.field_offset = offsetof(struct elants_data, _field),	\
991 		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
992 	}
993 
994 static ssize_t elants_version_attribute_show(struct device *dev,
995 					     struct device_attribute *dattr,
996 					     char *buf)
997 {
998 	struct i2c_client *client = to_i2c_client(dev);
999 	struct elants_data *ts = i2c_get_clientdata(client);
1000 	struct elants_version_attribute *attr =
1001 		container_of(dattr, struct elants_version_attribute, dattr);
1002 	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1003 	unsigned int fmt_size;
1004 	unsigned int val;
1005 
1006 	if (attr->field_size == 1) {
1007 		val = *field;
1008 		fmt_size = 2; /* 2 HEX digits */
1009 	} else {
1010 		val = *(u16 *)field;
1011 		fmt_size = 4; /* 4 HEX digits */
1012 	}
1013 
1014 	return sprintf(buf, "%0*x\n", fmt_size, val);
1015 }
1016 
1017 static ELANTS_VERSION_ATTR(fw_version);
1018 static ELANTS_VERSION_ATTR(hw_version);
1019 static ELANTS_VERSION_ATTR(test_version);
1020 static ELANTS_VERSION_ATTR(solution_version);
1021 static ELANTS_VERSION_ATTR(bc_version);
1022 static ELANTS_VERSION_ATTR(iap_version);
1023 
1024 static struct attribute *elants_attributes[] = {
1025 	&dev_attr_calibrate.attr,
1026 	&dev_attr_update_fw.attr,
1027 	&dev_attr_iap_mode.attr,
1028 
1029 	&elants_ver_attr_fw_version.dattr.attr,
1030 	&elants_ver_attr_hw_version.dattr.attr,
1031 	&elants_ver_attr_test_version.dattr.attr,
1032 	&elants_ver_attr_solution_version.dattr.attr,
1033 	&elants_ver_attr_bc_version.dattr.attr,
1034 	&elants_ver_attr_iap_version.dattr.attr,
1035 	NULL
1036 };
1037 
1038 static struct attribute_group elants_attribute_group = {
1039 	.attrs = elants_attributes,
1040 };
1041 
1042 static void elants_i2c_remove_sysfs_group(void *_data)
1043 {
1044 	struct elants_data *ts = _data;
1045 
1046 	sysfs_remove_group(&ts->client->dev.kobj, &elants_attribute_group);
1047 }
1048 
1049 static int elants_i2c_probe(struct i2c_client *client,
1050 			    const struct i2c_device_id *id)
1051 {
1052 	union i2c_smbus_data dummy;
1053 	struct elants_data *ts;
1054 	unsigned long irqflags;
1055 	int error;
1056 
1057 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1058 		dev_err(&client->dev,
1059 			"%s: i2c check functionality error\n", DEVICE_NAME);
1060 		return -ENXIO;
1061 	}
1062 
1063 	/* Make sure there is something at this address */
1064 	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1065 			I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1066 		dev_err(&client->dev, "nothing at this address\n");
1067 		return -ENXIO;
1068 	}
1069 
1070 	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1071 	if (!ts)
1072 		return -ENOMEM;
1073 
1074 	mutex_init(&ts->sysfs_mutex);
1075 	init_completion(&ts->cmd_done);
1076 
1077 	ts->client = client;
1078 	i2c_set_clientdata(client, ts);
1079 
1080 	error = elants_i2c_initialize(ts);
1081 	if (error) {
1082 		dev_err(&client->dev, "failed to initialize: %d\n", error);
1083 		return error;
1084 	}
1085 
1086 	ts->input = devm_input_allocate_device(&client->dev);
1087 	if (!ts->input) {
1088 		dev_err(&client->dev, "Failed to allocate input device\n");
1089 		return -ENOMEM;
1090 	}
1091 
1092 	ts->input->name = "Elan Touchscreen";
1093 	ts->input->id.bustype = BUS_I2C;
1094 
1095 	__set_bit(BTN_TOUCH, ts->input->keybit);
1096 	__set_bit(EV_ABS, ts->input->evbit);
1097 	__set_bit(EV_KEY, ts->input->evbit);
1098 
1099 	/* Single touch input params setup */
1100 	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1101 	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1102 	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1103 	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1104 	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1105 
1106 	/* Multitouch input params setup */
1107 	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1108 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1109 	if (error) {
1110 		dev_err(&client->dev,
1111 			"failed to initialize MT slots: %d\n", error);
1112 		return error;
1113 	}
1114 
1115 	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1116 	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1117 	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1118 	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1119 	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1120 	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1121 
1122 	input_set_drvdata(ts->input, ts);
1123 
1124 	error = input_register_device(ts->input);
1125 	if (error) {
1126 		dev_err(&client->dev,
1127 			"unable to register input device: %d\n", error);
1128 		return error;
1129 	}
1130 
1131 	/*
1132 	 * Systems using device tree should set up interrupt via DTS,
1133 	 * the rest will use the default falling edge interrupts.
1134 	 */
1135 	irqflags = client->dev.of_node ? 0 : IRQF_TRIGGER_FALLING;
1136 
1137 	error = devm_request_threaded_irq(&client->dev, client->irq,
1138 					  NULL, elants_i2c_irq,
1139 					  irqflags | IRQF_ONESHOT,
1140 					  client->name, ts);
1141 	if (error) {
1142 		dev_err(&client->dev, "Failed to register interrupt\n");
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 (!client->dev.of_node)
1151 		device_init_wakeup(&client->dev, true);
1152 
1153 	error = sysfs_create_group(&client->dev.kobj, &elants_attribute_group);
1154 	if (error) {
1155 		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1156 			error);
1157 		return error;
1158 	}
1159 
1160 	error = devm_add_action(&client->dev,
1161 				elants_i2c_remove_sysfs_group, ts);
1162 	if (error) {
1163 		elants_i2c_remove_sysfs_group(ts);
1164 		dev_err(&client->dev,
1165 			"Failed to add sysfs cleanup action: %d\n",
1166 			error);
1167 		return error;
1168 	}
1169 
1170 	return 0;
1171 }
1172 
1173 static int __maybe_unused elants_i2c_suspend(struct device *dev)
1174 {
1175 	struct i2c_client *client = to_i2c_client(dev);
1176 	struct elants_data *ts = i2c_get_clientdata(client);
1177 	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1178 	int retry_cnt;
1179 	int error;
1180 
1181 	/* Command not support in IAP recovery mode */
1182 	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1183 		return -EBUSY;
1184 
1185 	disable_irq(client->irq);
1186 
1187 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1188 		error = elants_i2c_send(client, set_sleep_cmd,
1189 					sizeof(set_sleep_cmd));
1190 		if (!error)
1191 			break;
1192 
1193 		dev_err(&client->dev, "suspend command failed: %d\n", error);
1194 	}
1195 
1196 	if (device_may_wakeup(dev))
1197 		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1198 
1199 	return 0;
1200 }
1201 
1202 static int __maybe_unused elants_i2c_resume(struct device *dev)
1203 {
1204 	struct i2c_client *client = to_i2c_client(dev);
1205 	struct elants_data *ts = i2c_get_clientdata(client);
1206 	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1207 	int retry_cnt;
1208 	int error;
1209 
1210 	if (device_may_wakeup(dev) && ts->wake_irq_enabled)
1211 		disable_irq_wake(client->irq);
1212 
1213 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1214 		error = elants_i2c_send(client, set_active_cmd,
1215 					sizeof(set_active_cmd));
1216 		if (!error)
1217 			break;
1218 
1219 		dev_err(&client->dev, "resume command failed: %d\n", error);
1220 	}
1221 
1222 	ts->state = ELAN_STATE_NORMAL;
1223 	enable_irq(client->irq);
1224 
1225 	return 0;
1226 }
1227 
1228 static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1229 			 elants_i2c_suspend, elants_i2c_resume);
1230 
1231 static const struct i2c_device_id elants_i2c_id[] = {
1232 	{ DEVICE_NAME, 0 },
1233 	{ }
1234 };
1235 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1236 
1237 #ifdef CONFIG_ACPI
1238 static const struct acpi_device_id elants_acpi_id[] = {
1239 	{ "ELAN0001", 0 },
1240 	{ }
1241 };
1242 MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1243 #endif
1244 
1245 #ifdef CONFIG_OF
1246 static const struct of_device_id elants_of_match[] = {
1247 	{ .compatible = "elan,ekth3500" },
1248 	{ /* sentinel */ }
1249 };
1250 MODULE_DEVICE_TABLE(of, elants_of_match);
1251 #endif
1252 
1253 static struct i2c_driver elants_i2c_driver = {
1254 	.probe = elants_i2c_probe,
1255 	.id_table = elants_i2c_id,
1256 	.driver = {
1257 		.name = DEVICE_NAME,
1258 		.owner = THIS_MODULE,
1259 		.pm = &elants_i2c_pm_ops,
1260 		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1261 		.of_match_table = of_match_ptr(elants_of_match),
1262 	},
1263 };
1264 module_i2c_driver(elants_i2c_driver);
1265 
1266 MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1267 MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1268 MODULE_VERSION(DRV_VERSION);
1269 MODULE_LICENSE("GPL");
1270