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 
102 /* calibration timeout definition */
103 #define ELAN_CALI_TIMEOUT_MSEC	10000
104 
105 enum elants_state {
106 	ELAN_STATE_NORMAL,
107 	ELAN_WAIT_QUEUE_HEADER,
108 	ELAN_WAIT_RECALIBRATION,
109 };
110 
111 enum elants_iap_mode {
112 	ELAN_IAP_OPERATIONAL,
113 	ELAN_IAP_RECOVERY,
114 };
115 
116 /* struct elants_data - represents state of Elan touchscreen device */
117 struct elants_data {
118 	struct i2c_client *client;
119 	struct input_dev *input;
120 
121 	u16 fw_version;
122 	u8 test_version;
123 	u8 solution_version;
124 	u8 bc_version;
125 	u8 iap_version;
126 	u16 hw_version;
127 	unsigned int x_res;	/* resolution in units/mm */
128 	unsigned int y_res;
129 	unsigned int x_max;
130 	unsigned int y_max;
131 
132 	enum elants_state state;
133 	enum elants_iap_mode iap_mode;
134 
135 	/* Guards against concurrent access to the device via sysfs */
136 	struct mutex sysfs_mutex;
137 
138 	u8 cmd_resp[HEADER_SIZE];
139 	struct completion cmd_done;
140 
141 	u8 buf[MAX_PACKET_SIZE];
142 
143 	bool wake_irq_enabled;
144 };
145 
146 static int elants_i2c_send(struct i2c_client *client,
147 			   const void *data, size_t size)
148 {
149 	int ret;
150 
151 	ret = i2c_master_send(client, data, size);
152 	if (ret == size)
153 		return 0;
154 
155 	if (ret >= 0)
156 		ret = -EIO;
157 
158 	dev_err(&client->dev, "%s failed (%*ph): %d\n",
159 		__func__, (int)size, data, ret);
160 
161 	return ret;
162 }
163 
164 static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
165 {
166 	int ret;
167 
168 	ret = i2c_master_recv(client, data, size);
169 	if (ret == size)
170 		return 0;
171 
172 	if (ret >= 0)
173 		ret = -EIO;
174 
175 	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
176 
177 	return ret;
178 }
179 
180 static int elants_i2c_execute_command(struct i2c_client *client,
181 				      const u8 *cmd, size_t cmd_size,
182 				      u8 *resp, size_t resp_size)
183 {
184 	struct i2c_msg msgs[2];
185 	int ret;
186 	u8 expected_response;
187 
188 	switch (cmd[0]) {
189 	case CMD_HEADER_READ:
190 		expected_response = CMD_HEADER_RESP;
191 		break;
192 
193 	case CMD_HEADER_6B_READ:
194 		expected_response = CMD_HEADER_6B_RESP;
195 		break;
196 
197 	default:
198 		dev_err(&client->dev, "%s: invalid command %*ph\n",
199 			__func__, (int)cmd_size, cmd);
200 		return -EINVAL;
201 	}
202 
203 	msgs[0].addr = client->addr;
204 	msgs[0].flags = client->flags & I2C_M_TEN;
205 	msgs[0].len = cmd_size;
206 	msgs[0].buf = (u8 *)cmd;
207 
208 	msgs[1].addr = client->addr;
209 	msgs[1].flags = client->flags & I2C_M_TEN;
210 	msgs[1].flags |= I2C_M_RD;
211 	msgs[1].len = resp_size;
212 	msgs[1].buf = resp;
213 
214 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
215 	if (ret < 0)
216 		return ret;
217 
218 	if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
219 		return -EIO;
220 
221 	return 0;
222 }
223 
224 static int elants_i2c_calibrate(struct elants_data *ts)
225 {
226 	struct i2c_client *client = ts->client;
227 	int ret, error;
228 	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
229 	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
230 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
231 
232 	disable_irq(client->irq);
233 
234 	ts->state = ELAN_WAIT_RECALIBRATION;
235 	reinit_completion(&ts->cmd_done);
236 
237 	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
238 	elants_i2c_send(client, rek, sizeof(rek));
239 
240 	enable_irq(client->irq);
241 
242 	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
243 				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
244 
245 	ts->state = ELAN_STATE_NORMAL;
246 
247 	if (ret <= 0) {
248 		error = ret < 0 ? ret : -ETIMEDOUT;
249 		dev_err(&client->dev,
250 			"error while waiting for calibration to complete: %d\n",
251 			error);
252 		return error;
253 	}
254 
255 	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
256 		dev_err(&client->dev,
257 			"unexpected calibration response: %*ph\n",
258 			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
259 		return -EINVAL;
260 	}
261 
262 	return 0;
263 }
264 
265 static int elants_i2c_sw_reset(struct i2c_client *client)
266 {
267 	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
268 	int error;
269 
270 	error = elants_i2c_send(client, soft_rst_cmd,
271 				sizeof(soft_rst_cmd));
272 	if (error) {
273 		dev_err(&client->dev, "software reset failed: %d\n", error);
274 		return error;
275 	}
276 
277 	/*
278 	 * We should wait at least 10 msec (but no more than 40) before
279 	 * sending fastboot or IAP command to the device.
280 	 */
281 	msleep(30);
282 
283 	return 0;
284 }
285 
286 static u16 elants_i2c_parse_version(u8 *buf)
287 {
288 	return get_unaligned_be32(buf) >> 4;
289 }
290 
291 static int elants_i2c_query_fw_id(struct elants_data *ts)
292 {
293 	struct i2c_client *client = ts->client;
294 	int error, retry_cnt;
295 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
296 	u8 resp[HEADER_SIZE];
297 
298 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
299 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
300 						   resp, sizeof(resp));
301 		if (!error) {
302 			ts->hw_version = elants_i2c_parse_version(resp);
303 			if (ts->hw_version != 0xffff)
304 				return 0;
305 		}
306 
307 		dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
308 			error, (int)sizeof(resp), resp);
309 	}
310 
311 	dev_err(&client->dev,
312 		"Failed to read fw id or fw id is invalid\n");
313 
314 	return -EINVAL;
315 }
316 
317 static int elants_i2c_query_fw_version(struct elants_data *ts)
318 {
319 	struct i2c_client *client = ts->client;
320 	int error, retry_cnt;
321 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
322 	u8 resp[HEADER_SIZE];
323 
324 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
325 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
326 						   resp, sizeof(resp));
327 		if (!error) {
328 			ts->fw_version = elants_i2c_parse_version(resp);
329 			if (ts->fw_version != 0x0000 &&
330 			    ts->fw_version != 0xffff)
331 				return 0;
332 		}
333 
334 		dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
335 			error, (int)sizeof(resp), resp);
336 	}
337 
338 	dev_err(&client->dev,
339 		"Failed to read fw version or fw version is invalid\n");
340 
341 	return -EINVAL;
342 }
343 
344 static int elants_i2c_query_test_version(struct elants_data *ts)
345 {
346 	struct i2c_client *client = ts->client;
347 	int error, retry_cnt;
348 	u16 version;
349 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
350 	u8 resp[HEADER_SIZE];
351 
352 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
353 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
354 						   resp, sizeof(resp));
355 		if (!error) {
356 			version = elants_i2c_parse_version(resp);
357 			ts->test_version = version >> 8;
358 			ts->solution_version = version & 0xff;
359 
360 			return 0;
361 		}
362 
363 		dev_dbg(&client->dev,
364 			"read test version error rc=%d, buf=%*phC\n",
365 			error, (int)sizeof(resp), resp);
366 	}
367 
368 	dev_err(&client->dev, "Failed to read test version\n");
369 
370 	return -EINVAL;
371 }
372 
373 static int elants_i2c_query_bc_version(struct elants_data *ts)
374 {
375 	struct i2c_client *client = ts->client;
376 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
377 	u8 resp[HEADER_SIZE];
378 	u16 version;
379 	int error;
380 
381 	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
382 					   resp, sizeof(resp));
383 	if (error) {
384 		dev_err(&client->dev,
385 			"read BC version error=%d, buf=%*phC\n",
386 			error, (int)sizeof(resp), resp);
387 		return error;
388 	}
389 
390 	version = elants_i2c_parse_version(resp);
391 	ts->bc_version = version >> 8;
392 	ts->iap_version = version & 0xff;
393 
394 	return 0;
395 }
396 
397 static int elants_i2c_query_ts_info(struct elants_data *ts)
398 {
399 	struct i2c_client *client = ts->client;
400 	int error;
401 	u8 resp[17];
402 	u16 phy_x, phy_y, rows, cols, osr;
403 	const u8 get_resolution_cmd[] = {
404 		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
405 	};
406 	const u8 get_osr_cmd[] = {
407 		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
408 	};
409 	const u8 get_physical_scan_cmd[] = {
410 		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
411 	};
412 	const u8 get_physical_drive_cmd[] = {
413 		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
414 	};
415 
416 	/* Get trace number */
417 	error = elants_i2c_execute_command(client,
418 					   get_resolution_cmd,
419 					   sizeof(get_resolution_cmd),
420 					   resp, sizeof(resp));
421 	if (error) {
422 		dev_err(&client->dev, "get resolution command failed: %d\n",
423 			error);
424 		return error;
425 	}
426 
427 	rows = resp[2] + resp[6] + resp[10];
428 	cols = resp[3] + resp[7] + resp[11];
429 
430 	/* Process mm_to_pixel information */
431 	error = elants_i2c_execute_command(client,
432 					   get_osr_cmd, sizeof(get_osr_cmd),
433 					   resp, sizeof(resp));
434 	if (error) {
435 		dev_err(&client->dev, "get osr command failed: %d\n",
436 			error);
437 		return error;
438 	}
439 
440 	osr = resp[3];
441 
442 	error = elants_i2c_execute_command(client,
443 					   get_physical_scan_cmd,
444 					   sizeof(get_physical_scan_cmd),
445 					   resp, sizeof(resp));
446 	if (error) {
447 		dev_err(&client->dev, "get physical scan command failed: %d\n",
448 			error);
449 		return error;
450 	}
451 
452 	phy_x = get_unaligned_be16(&resp[2]);
453 
454 	error = elants_i2c_execute_command(client,
455 					   get_physical_drive_cmd,
456 					   sizeof(get_physical_drive_cmd),
457 					   resp, sizeof(resp));
458 	if (error) {
459 		dev_err(&client->dev, "get physical drive command failed: %d\n",
460 			error);
461 		return error;
462 	}
463 
464 	phy_y = get_unaligned_be16(&resp[2]);
465 
466 	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
467 
468 	if (rows == 0 || cols == 0 || osr == 0) {
469 		dev_warn(&client->dev,
470 			 "invalid trace number data: %d, %d, %d\n",
471 			 rows, cols, osr);
472 	} else {
473 		/* translate trace number to TS resolution */
474 		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
475 		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
476 		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
477 		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
478 	}
479 
480 	return 0;
481 }
482 
483 static int elants_i2c_fastboot(struct i2c_client *client)
484 {
485 	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
486 	int error;
487 
488 	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
489 	if (error) {
490 		dev_err(&client->dev, "boot failed: %d\n", error);
491 		return error;
492 	}
493 
494 	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
495 	return 0;
496 }
497 
498 static int elants_i2c_initialize(struct elants_data *ts)
499 {
500 	struct i2c_client *client = ts->client;
501 	int error, retry_cnt;
502 	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
503 	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
504 	u8 buf[HEADER_SIZE];
505 
506 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
507 		error = elants_i2c_sw_reset(client);
508 		if (error) {
509 			/* Continue initializing if it's the last try */
510 			if (retry_cnt < MAX_RETRIES - 1)
511 				continue;
512 		}
513 
514 		error = elants_i2c_fastboot(client);
515 		if (error) {
516 			/* Continue initializing if it's the last try */
517 			if (retry_cnt < MAX_RETRIES - 1)
518 				continue;
519 		}
520 
521 		/* Wait for Hello packet */
522 		msleep(BOOT_TIME_DELAY_MS);
523 
524 		error = elants_i2c_read(client, buf, sizeof(buf));
525 		if (error) {
526 			dev_err(&client->dev,
527 				"failed to read 'hello' packet: %d\n", error);
528 		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
529 			ts->iap_mode = ELAN_IAP_OPERATIONAL;
530 			break;
531 		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
532 			/*
533 			 * Setting error code will mark device
534 			 * in recovery mode below.
535 			 */
536 			error = -EIO;
537 			break;
538 		} else {
539 			error = -EINVAL;
540 			dev_err(&client->dev,
541 				"invalid 'hello' packet: %*ph\n",
542 				(int)sizeof(buf), buf);
543 		}
544 	}
545 
546 	if (!error)
547 		error = elants_i2c_query_fw_id(ts);
548 	if (!error)
549 		error = elants_i2c_query_fw_version(ts);
550 
551 	if (error) {
552 		ts->iap_mode = ELAN_IAP_RECOVERY;
553 	} else {
554 		elants_i2c_query_test_version(ts);
555 		elants_i2c_query_bc_version(ts);
556 		elants_i2c_query_ts_info(ts);
557 	}
558 
559 	return 0;
560 }
561 
562 /*
563  * Firmware update interface.
564  */
565 
566 static int elants_i2c_fw_write_page(struct i2c_client *client,
567 				    const void *page)
568 {
569 	const u8 ack_ok[] = { 0xaa, 0xaa };
570 	u8 buf[2];
571 	int retry;
572 	int error;
573 
574 	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
575 		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
576 		if (error) {
577 			dev_err(&client->dev,
578 				"IAP Write Page failed: %d\n", error);
579 			continue;
580 		}
581 
582 		error = elants_i2c_read(client, buf, 2);
583 		if (error) {
584 			dev_err(&client->dev,
585 				"IAP Ack read failed: %d\n", error);
586 			return error;
587 		}
588 
589 		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
590 			return 0;
591 
592 		error = -EIO;
593 		dev_err(&client->dev,
594 			"IAP Get Ack Error [%02x:%02x]\n",
595 			buf[0], buf[1]);
596 	}
597 
598 	return error;
599 }
600 
601 static int elants_i2c_do_update_firmware(struct i2c_client *client,
602 					 const struct firmware *fw,
603 					 bool force)
604 {
605 	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
606 	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
607 	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
608 	const u8 close_idle[] = {0x54, 0x2c, 0x01, 0x01};
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 		/* Close idle mode */
622 		error = elants_i2c_send(client, close_idle, sizeof(close_idle));
623 		if (error)
624 			dev_err(&client->dev, "Failed close idle: %d\n", error);
625 		msleep(60);
626 		elants_i2c_sw_reset(client);
627 		msleep(20);
628 		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
629 	}
630 
631 	if (error) {
632 		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
633 		return error;
634 	}
635 
636 	msleep(20);
637 
638 	/* check IAP state */
639 	error = elants_i2c_read(client, buf, 4);
640 	if (error) {
641 		dev_err(&client->dev,
642 			"failed to read IAP acknowledgement: %d\n",
643 			error);
644 		return error;
645 	}
646 
647 	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
648 		dev_err(&client->dev,
649 			"failed to enter IAP: %*ph (expected %*ph)\n",
650 			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
651 		return -EIO;
652 	}
653 
654 	dev_info(&client->dev, "successfully entered IAP mode");
655 
656 	send_id = client->addr;
657 	error = elants_i2c_send(client, &send_id, 1);
658 	if (error) {
659 		dev_err(&client->dev, "sending dummy byte failed: %d\n",
660 			error);
661 		return error;
662 	}
663 
664 	/* Clear the last page of Master */
665 	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
666 	if (error) {
667 		dev_err(&client->dev, "clearing of the last page failed: %d\n",
668 			error);
669 		return error;
670 	}
671 
672 	error = elants_i2c_read(client, buf, 2);
673 	if (error) {
674 		dev_err(&client->dev,
675 			"failed to read ACK for clearing the last page: %d\n",
676 			error);
677 		return error;
678 	}
679 
680 	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
681 	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
682 
683 	for (page = 0; page < n_fw_pages; page++) {
684 		error = elants_i2c_fw_write_page(client,
685 					fw->data + page * ELAN_FW_PAGESIZE);
686 		if (error) {
687 			dev_err(&client->dev,
688 				"failed to write FW page %d: %d\n",
689 				page, error);
690 			return error;
691 		}
692 	}
693 
694 	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
695 	msleep(300);
696 
697 	dev_info(&client->dev, "firmware update completed\n");
698 	return 0;
699 }
700 
701 static int elants_i2c_fw_update(struct elants_data *ts)
702 {
703 	struct i2c_client *client = ts->client;
704 	const struct firmware *fw;
705 	char *fw_name;
706 	int error;
707 
708 	fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
709 	if (!fw_name)
710 		return -ENOMEM;
711 
712 	dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
713 	error = request_firmware(&fw, fw_name, &client->dev);
714 	kfree(fw_name);
715 	if (error) {
716 		dev_err(&client->dev, "failed to request firmware: %d\n",
717 			error);
718 		return error;
719 	}
720 
721 	if (fw->size % ELAN_FW_PAGESIZE) {
722 		dev_err(&client->dev, "invalid firmware length: %zu\n",
723 			fw->size);
724 		error = -EINVAL;
725 		goto out;
726 	}
727 
728 	disable_irq(client->irq);
729 
730 	error = elants_i2c_do_update_firmware(client, fw,
731 					ts->iap_mode == ELAN_IAP_RECOVERY);
732 	if (error) {
733 		dev_err(&client->dev, "firmware update failed: %d\n", error);
734 		ts->iap_mode = ELAN_IAP_RECOVERY;
735 		goto out_enable_irq;
736 	}
737 
738 	error = elants_i2c_initialize(ts);
739 	if (error) {
740 		dev_err(&client->dev,
741 			"failed to initialize device after firmware update: %d\n",
742 			error);
743 		ts->iap_mode = ELAN_IAP_RECOVERY;
744 		goto out_enable_irq;
745 	}
746 
747 	ts->iap_mode = ELAN_IAP_OPERATIONAL;
748 
749 out_enable_irq:
750 	ts->state = ELAN_STATE_NORMAL;
751 	enable_irq(client->irq);
752 	msleep(100);
753 
754 	if (!error)
755 		elants_i2c_calibrate(ts);
756 out:
757 	release_firmware(fw);
758 	return error;
759 }
760 
761 /*
762  * Event reporting.
763  */
764 
765 static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
766 {
767 	struct input_dev *input = ts->input;
768 	unsigned int n_fingers;
769 	u16 finger_state;
770 	int i;
771 
772 	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
773 	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
774 			buf[FW_POS_STATE];
775 
776 	dev_dbg(&ts->client->dev,
777 		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
778 
779 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
780 		if (finger_state & 1) {
781 			unsigned int x, y, p, w;
782 			u8 *pos;
783 
784 			pos = &buf[FW_POS_XY + i * 3];
785 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
786 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
787 			p = buf[FW_POS_PRESSURE + i];
788 			w = buf[FW_POS_WIDTH + i];
789 
790 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
791 				i, x, y, p, w);
792 
793 			input_mt_slot(input, i);
794 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
795 			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
796 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
797 			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
798 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
799 
800 			n_fingers--;
801 		}
802 
803 		finger_state >>= 1;
804 	}
805 
806 	input_mt_sync_frame(input);
807 	input_sync(input);
808 }
809 
810 static u8 elants_i2c_calculate_checksum(u8 *buf)
811 {
812 	u8 checksum = 0;
813 	u8 i;
814 
815 	for (i = 0; i < FW_POS_CHECKSUM; i++)
816 		checksum += buf[i];
817 
818 	return checksum;
819 }
820 
821 static void elants_i2c_event(struct elants_data *ts, u8 *buf)
822 {
823 	u8 checksum = elants_i2c_calculate_checksum(buf);
824 
825 	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
826 		dev_warn(&ts->client->dev,
827 			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
828 			 __func__, buf[FW_POS_HEADER],
829 			 checksum, buf[FW_POS_CHECKSUM]);
830 	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
831 		dev_warn(&ts->client->dev,
832 			 "%s: unknown packet type: %02x\n",
833 			 __func__, buf[FW_POS_HEADER]);
834 	else
835 		elants_i2c_mt_event(ts, buf);
836 }
837 
838 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
839 {
840 	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
841 	struct elants_data *ts = _dev;
842 	struct i2c_client *client = ts->client;
843 	int report_count, report_len;
844 	int i;
845 	int len;
846 
847 	len = i2c_master_recv(client, ts->buf, sizeof(ts->buf));
848 	if (len < 0) {
849 		dev_err(&client->dev, "%s: failed to read data: %d\n",
850 			__func__, len);
851 		goto out;
852 	}
853 
854 	dev_dbg(&client->dev, "%s: packet %*ph\n",
855 		__func__, HEADER_SIZE, ts->buf);
856 
857 	switch (ts->state) {
858 	case ELAN_WAIT_RECALIBRATION:
859 		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
860 			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
861 			complete(&ts->cmd_done);
862 			ts->state = ELAN_STATE_NORMAL;
863 		}
864 		break;
865 
866 	case ELAN_WAIT_QUEUE_HEADER:
867 		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
868 			break;
869 
870 		ts->state = ELAN_STATE_NORMAL;
871 		/* fall through */
872 
873 	case ELAN_STATE_NORMAL:
874 
875 		switch (ts->buf[FW_HDR_TYPE]) {
876 		case CMD_HEADER_HELLO:
877 		case CMD_HEADER_RESP:
878 		case CMD_HEADER_REK:
879 			break;
880 
881 		case QUEUE_HEADER_WAIT:
882 			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
883 				dev_err(&client->dev,
884 					"invalid wait packet %*ph\n",
885 					HEADER_SIZE, ts->buf);
886 			} else {
887 				ts->state = ELAN_WAIT_QUEUE_HEADER;
888 				udelay(30);
889 			}
890 			break;
891 
892 		case QUEUE_HEADER_SINGLE:
893 			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
894 			break;
895 
896 		case QUEUE_HEADER_NORMAL:
897 			report_count = ts->buf[FW_HDR_COUNT];
898 			if (report_count > 3) {
899 				dev_err(&client->dev,
900 					"too large report count: %*ph\n",
901 					HEADER_SIZE, ts->buf);
902 				break;
903 			}
904 
905 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
906 			if (report_len != PACKET_SIZE) {
907 				dev_err(&client->dev,
908 					"mismatching report length: %*ph\n",
909 					HEADER_SIZE, ts->buf);
910 				break;
911 			}
912 
913 			for (i = 0; i < report_count; i++) {
914 				u8 *buf = ts->buf + HEADER_SIZE +
915 							i * PACKET_SIZE;
916 				elants_i2c_event(ts, buf);
917 			}
918 			break;
919 
920 		default:
921 			dev_err(&client->dev, "unknown packet %*ph\n",
922 				HEADER_SIZE, ts->buf);
923 			break;
924 		}
925 		break;
926 	}
927 
928 out:
929 	return IRQ_HANDLED;
930 }
931 
932 /*
933  * sysfs interface
934  */
935 static ssize_t calibrate_store(struct device *dev,
936 			       struct device_attribute *attr,
937 			      const char *buf, size_t count)
938 {
939 	struct i2c_client *client = to_i2c_client(dev);
940 	struct elants_data *ts = i2c_get_clientdata(client);
941 	int error;
942 
943 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
944 	if (error)
945 		return error;
946 
947 	error = elants_i2c_calibrate(ts);
948 
949 	mutex_unlock(&ts->sysfs_mutex);
950 	return error ?: count;
951 }
952 
953 static ssize_t write_update_fw(struct device *dev,
954 			       struct device_attribute *attr,
955 			       const char *buf, size_t count)
956 {
957 	struct i2c_client *client = to_i2c_client(dev);
958 	struct elants_data *ts = i2c_get_clientdata(client);
959 	int error;
960 
961 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
962 	if (error)
963 		return error;
964 
965 	error = elants_i2c_fw_update(ts);
966 	dev_dbg(dev, "firmware update result: %d\n", error);
967 
968 	mutex_unlock(&ts->sysfs_mutex);
969 	return error ?: count;
970 }
971 
972 static ssize_t show_iap_mode(struct device *dev,
973 			     struct device_attribute *attr, char *buf)
974 {
975 	struct i2c_client *client = to_i2c_client(dev);
976 	struct elants_data *ts = i2c_get_clientdata(client);
977 
978 	return sprintf(buf, "%s\n",
979 		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
980 				"Normal" : "Recovery");
981 }
982 
983 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, calibrate_store);
984 static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
985 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
986 
987 struct elants_version_attribute {
988 	struct device_attribute dattr;
989 	size_t field_offset;
990 	size_t field_size;
991 };
992 
993 #define __ELANTS_FIELD_SIZE(_field)					\
994 	sizeof(((struct elants_data *)NULL)->_field)
995 #define __ELANTS_VERIFY_SIZE(_field)					\
996 	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
997 	 __ELANTS_FIELD_SIZE(_field))
998 #define ELANTS_VERSION_ATTR(_field)					\
999 	struct elants_version_attribute elants_ver_attr_##_field = {	\
1000 		.dattr = __ATTR(_field, S_IRUGO,			\
1001 				elants_version_attribute_show, NULL),	\
1002 		.field_offset = offsetof(struct elants_data, _field),	\
1003 		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
1004 	}
1005 
1006 static ssize_t elants_version_attribute_show(struct device *dev,
1007 					     struct device_attribute *dattr,
1008 					     char *buf)
1009 {
1010 	struct i2c_client *client = to_i2c_client(dev);
1011 	struct elants_data *ts = i2c_get_clientdata(client);
1012 	struct elants_version_attribute *attr =
1013 		container_of(dattr, struct elants_version_attribute, dattr);
1014 	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1015 	unsigned int fmt_size;
1016 	unsigned int val;
1017 
1018 	if (attr->field_size == 1) {
1019 		val = *field;
1020 		fmt_size = 2; /* 2 HEX digits */
1021 	} else {
1022 		val = *(u16 *)field;
1023 		fmt_size = 4; /* 4 HEX digits */
1024 	}
1025 
1026 	return sprintf(buf, "%0*x\n", fmt_size, val);
1027 }
1028 
1029 static ELANTS_VERSION_ATTR(fw_version);
1030 static ELANTS_VERSION_ATTR(hw_version);
1031 static ELANTS_VERSION_ATTR(test_version);
1032 static ELANTS_VERSION_ATTR(solution_version);
1033 static ELANTS_VERSION_ATTR(bc_version);
1034 static ELANTS_VERSION_ATTR(iap_version);
1035 
1036 static struct attribute *elants_attributes[] = {
1037 	&dev_attr_calibrate.attr,
1038 	&dev_attr_update_fw.attr,
1039 	&dev_attr_iap_mode.attr,
1040 
1041 	&elants_ver_attr_fw_version.dattr.attr,
1042 	&elants_ver_attr_hw_version.dattr.attr,
1043 	&elants_ver_attr_test_version.dattr.attr,
1044 	&elants_ver_attr_solution_version.dattr.attr,
1045 	&elants_ver_attr_bc_version.dattr.attr,
1046 	&elants_ver_attr_iap_version.dattr.attr,
1047 	NULL
1048 };
1049 
1050 static struct attribute_group elants_attribute_group = {
1051 	.attrs = elants_attributes,
1052 };
1053 
1054 static void elants_i2c_remove_sysfs_group(void *_data)
1055 {
1056 	struct elants_data *ts = _data;
1057 
1058 	sysfs_remove_group(&ts->client->dev.kobj, &elants_attribute_group);
1059 }
1060 
1061 static int elants_i2c_probe(struct i2c_client *client,
1062 			    const struct i2c_device_id *id)
1063 {
1064 	union i2c_smbus_data dummy;
1065 	struct elants_data *ts;
1066 	unsigned long irqflags;
1067 	int error;
1068 
1069 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1070 		dev_err(&client->dev,
1071 			"%s: i2c check functionality error\n", DEVICE_NAME);
1072 		return -ENXIO;
1073 	}
1074 
1075 	/* Make sure there is something at this address */
1076 	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1077 			I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1078 		dev_err(&client->dev, "nothing at this address\n");
1079 		return -ENXIO;
1080 	}
1081 
1082 	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1083 	if (!ts)
1084 		return -ENOMEM;
1085 
1086 	mutex_init(&ts->sysfs_mutex);
1087 	init_completion(&ts->cmd_done);
1088 
1089 	ts->client = client;
1090 	i2c_set_clientdata(client, ts);
1091 
1092 	error = elants_i2c_initialize(ts);
1093 	if (error) {
1094 		dev_err(&client->dev, "failed to initialize: %d\n", error);
1095 		return error;
1096 	}
1097 
1098 	ts->input = devm_input_allocate_device(&client->dev);
1099 	if (!ts->input) {
1100 		dev_err(&client->dev, "Failed to allocate input device\n");
1101 		return -ENOMEM;
1102 	}
1103 
1104 	ts->input->name = "Elan Touchscreen";
1105 	ts->input->id.bustype = BUS_I2C;
1106 
1107 	__set_bit(BTN_TOUCH, ts->input->keybit);
1108 	__set_bit(EV_ABS, ts->input->evbit);
1109 	__set_bit(EV_KEY, ts->input->evbit);
1110 
1111 	/* Single touch input params setup */
1112 	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1113 	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1114 	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1115 	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1116 	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1117 
1118 	/* Multitouch input params setup */
1119 	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1120 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1121 	if (error) {
1122 		dev_err(&client->dev,
1123 			"failed to initialize MT slots: %d\n", error);
1124 		return error;
1125 	}
1126 
1127 	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1128 	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1129 	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1130 	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1131 	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1132 	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1133 
1134 	input_set_drvdata(ts->input, ts);
1135 
1136 	error = input_register_device(ts->input);
1137 	if (error) {
1138 		dev_err(&client->dev,
1139 			"unable to register input device: %d\n", error);
1140 		return error;
1141 	}
1142 
1143 	/*
1144 	 * Systems using device tree should set up interrupt via DTS,
1145 	 * the rest will use the default falling edge interrupts.
1146 	 */
1147 	irqflags = client->dev.of_node ? 0 : IRQF_TRIGGER_FALLING;
1148 
1149 	error = devm_request_threaded_irq(&client->dev, client->irq,
1150 					  NULL, elants_i2c_irq,
1151 					  irqflags | IRQF_ONESHOT,
1152 					  client->name, ts);
1153 	if (error) {
1154 		dev_err(&client->dev, "Failed to register interrupt\n");
1155 		return error;
1156 	}
1157 
1158 	/*
1159 	 * Systems using device tree should set up wakeup via DTS,
1160 	 * the rest will configure device as wakeup source by default.
1161 	 */
1162 	if (!client->dev.of_node)
1163 		device_init_wakeup(&client->dev, true);
1164 
1165 	error = sysfs_create_group(&client->dev.kobj, &elants_attribute_group);
1166 	if (error) {
1167 		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1168 			error);
1169 		return error;
1170 	}
1171 
1172 	error = devm_add_action(&client->dev,
1173 				elants_i2c_remove_sysfs_group, ts);
1174 	if (error) {
1175 		elants_i2c_remove_sysfs_group(ts);
1176 		dev_err(&client->dev,
1177 			"Failed to add sysfs cleanup action: %d\n",
1178 			error);
1179 		return error;
1180 	}
1181 
1182 	return 0;
1183 }
1184 
1185 static int __maybe_unused elants_i2c_suspend(struct device *dev)
1186 {
1187 	struct i2c_client *client = to_i2c_client(dev);
1188 	struct elants_data *ts = i2c_get_clientdata(client);
1189 	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1190 	int retry_cnt;
1191 	int error;
1192 
1193 	/* Command not support in IAP recovery mode */
1194 	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1195 		return -EBUSY;
1196 
1197 	disable_irq(client->irq);
1198 
1199 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1200 		error = elants_i2c_send(client, set_sleep_cmd,
1201 					sizeof(set_sleep_cmd));
1202 		if (!error)
1203 			break;
1204 
1205 		dev_err(&client->dev, "suspend command failed: %d\n", error);
1206 	}
1207 
1208 	if (device_may_wakeup(dev))
1209 		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1210 
1211 	return 0;
1212 }
1213 
1214 static int __maybe_unused elants_i2c_resume(struct device *dev)
1215 {
1216 	struct i2c_client *client = to_i2c_client(dev);
1217 	struct elants_data *ts = i2c_get_clientdata(client);
1218 	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1219 	int retry_cnt;
1220 	int error;
1221 
1222 	if (device_may_wakeup(dev) && ts->wake_irq_enabled)
1223 		disable_irq_wake(client->irq);
1224 
1225 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1226 		error = elants_i2c_send(client, set_active_cmd,
1227 					sizeof(set_active_cmd));
1228 		if (!error)
1229 			break;
1230 
1231 		dev_err(&client->dev, "resume command failed: %d\n", error);
1232 	}
1233 
1234 	ts->state = ELAN_STATE_NORMAL;
1235 	enable_irq(client->irq);
1236 
1237 	return 0;
1238 }
1239 
1240 static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1241 			 elants_i2c_suspend, elants_i2c_resume);
1242 
1243 static const struct i2c_device_id elants_i2c_id[] = {
1244 	{ DEVICE_NAME, 0 },
1245 	{ }
1246 };
1247 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1248 
1249 #ifdef CONFIG_ACPI
1250 static const struct acpi_device_id elants_acpi_id[] = {
1251 	{ "ELAN0001", 0 },
1252 	{ }
1253 };
1254 MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1255 #endif
1256 
1257 #ifdef CONFIG_OF
1258 static const struct of_device_id elants_of_match[] = {
1259 	{ .compatible = "elan,ekth3500" },
1260 	{ /* sentinel */ }
1261 };
1262 MODULE_DEVICE_TABLE(of, elants_of_match);
1263 #endif
1264 
1265 static struct i2c_driver elants_i2c_driver = {
1266 	.probe = elants_i2c_probe,
1267 	.id_table = elants_i2c_id,
1268 	.driver = {
1269 		.name = DEVICE_NAME,
1270 		.pm = &elants_i2c_pm_ops,
1271 		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1272 		.of_match_table = of_match_ptr(elants_of_match),
1273 	},
1274 };
1275 module_i2c_driver(elants_i2c_driver);
1276 
1277 MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1278 MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1279 MODULE_VERSION(DRV_VERSION);
1280 MODULE_LICENSE("GPL");
1281