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
105enum elants_state {
106	ELAN_STATE_NORMAL,
107	ELAN_WAIT_QUEUE_HEADER,
108	ELAN_WAIT_RECALIBRATION,
109};
110
111enum elants_iap_mode {
112	ELAN_IAP_OPERATIONAL,
113	ELAN_IAP_RECOVERY,
114};
115
116/* struct elants_data - represents state of Elan touchscreen device */
117struct 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
146static 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
164static 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
180static 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
224static 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
265static 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
286static u16 elants_i2c_parse_version(u8 *buf)
287{
288	return get_unaligned_be32(buf) >> 4;
289}
290
291static 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
317static 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
344static 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
373static 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
397static 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
483static 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
498static 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
566static 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
601static 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	u8 buf[HEADER_SIZE];
609	u16 send_id;
610	int page, n_fw_pages;
611	int error;
612
613	/* Recovery mode detection! */
614	if (force) {
615		dev_dbg(&client->dev, "Recovery mode procedure\n");
616		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
617	} else {
618		/* Start IAP Procedure */
619		dev_dbg(&client->dev, "Normal IAP procedure\n");
620		elants_i2c_sw_reset(client);
621
622		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
623	}
624
625	if (error) {
626		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
627		return error;
628	}
629
630	msleep(20);
631
632	/* check IAP state */
633	error = elants_i2c_read(client, buf, 4);
634	if (error) {
635		dev_err(&client->dev,
636			"failed to read IAP acknowledgement: %d\n",
637			error);
638		return error;
639	}
640
641	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
642		dev_err(&client->dev,
643			"failed to enter IAP: %*ph (expected %*ph)\n",
644			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
645		return -EIO;
646	}
647
648	dev_info(&client->dev, "successfully entered IAP mode");
649
650	send_id = client->addr;
651	error = elants_i2c_send(client, &send_id, 1);
652	if (error) {
653		dev_err(&client->dev, "sending dummy byte failed: %d\n",
654			error);
655		return error;
656	}
657
658	/* Clear the last page of Master */
659	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
660	if (error) {
661		dev_err(&client->dev, "clearing of the last page failed: %d\n",
662			error);
663		return error;
664	}
665
666	error = elants_i2c_read(client, buf, 2);
667	if (error) {
668		dev_err(&client->dev,
669			"failed to read ACK for clearing the last page: %d\n",
670			error);
671		return error;
672	}
673
674	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
675	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
676
677	for (page = 0; page < n_fw_pages; page++) {
678		error = elants_i2c_fw_write_page(client,
679					fw->data + page * ELAN_FW_PAGESIZE);
680		if (error) {
681			dev_err(&client->dev,
682				"failed to write FW page %d: %d\n",
683				page, error);
684			return error;
685		}
686	}
687
688	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
689	msleep(300);
690
691	dev_info(&client->dev, "firmware update completed\n");
692	return 0;
693}
694
695static int elants_i2c_fw_update(struct elants_data *ts)
696{
697	struct i2c_client *client = ts->client;
698	const struct firmware *fw;
699	char *fw_name;
700	int error;
701
702	fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
703	if (!fw_name)
704		return -ENOMEM;
705
706	dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
707	error = request_firmware(&fw, fw_name, &client->dev);
708	kfree(fw_name);
709	if (error) {
710		dev_err(&client->dev, "failed to request firmware: %d\n",
711			error);
712		return error;
713	}
714
715	if (fw->size % ELAN_FW_PAGESIZE) {
716		dev_err(&client->dev, "invalid firmware length: %zu\n",
717			fw->size);
718		error = -EINVAL;
719		goto out;
720	}
721
722	disable_irq(client->irq);
723
724	error = elants_i2c_do_update_firmware(client, fw,
725					ts->iap_mode == ELAN_IAP_RECOVERY);
726	if (error) {
727		dev_err(&client->dev, "firmware update failed: %d\n", error);
728		ts->iap_mode = ELAN_IAP_RECOVERY;
729		goto out_enable_irq;
730	}
731
732	error = elants_i2c_initialize(ts);
733	if (error) {
734		dev_err(&client->dev,
735			"failed to initialize device after firmware update: %d\n",
736			error);
737		ts->iap_mode = ELAN_IAP_RECOVERY;
738		goto out_enable_irq;
739	}
740
741	ts->iap_mode = ELAN_IAP_OPERATIONAL;
742
743out_enable_irq:
744	ts->state = ELAN_STATE_NORMAL;
745	enable_irq(client->irq);
746	msleep(100);
747
748	if (!error)
749		elants_i2c_calibrate(ts);
750out:
751	release_firmware(fw);
752	return error;
753}
754
755/*
756 * Event reporting.
757 */
758
759static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
760{
761	struct input_dev *input = ts->input;
762	unsigned int n_fingers;
763	u16 finger_state;
764	int i;
765
766	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
767	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
768			buf[FW_POS_STATE];
769
770	dev_dbg(&ts->client->dev,
771		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
772
773	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
774		if (finger_state & 1) {
775			unsigned int x, y, p, w;
776			u8 *pos;
777
778			pos = &buf[FW_POS_XY + i * 3];
779			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
780			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
781			p = buf[FW_POS_PRESSURE + i];
782			w = buf[FW_POS_WIDTH + i];
783
784			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
785				i, x, y, p, w);
786
787			input_mt_slot(input, i);
788			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
789			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
790			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
791			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
792			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
793
794			n_fingers--;
795		}
796
797		finger_state >>= 1;
798	}
799
800	input_mt_sync_frame(input);
801	input_sync(input);
802}
803
804static u8 elants_i2c_calculate_checksum(u8 *buf)
805{
806	u8 checksum = 0;
807	u8 i;
808
809	for (i = 0; i < FW_POS_CHECKSUM; i++)
810		checksum += buf[i];
811
812	return checksum;
813}
814
815static void elants_i2c_event(struct elants_data *ts, u8 *buf)
816{
817	u8 checksum = elants_i2c_calculate_checksum(buf);
818
819	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
820		dev_warn(&ts->client->dev,
821			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
822			 __func__, buf[FW_POS_HEADER],
823			 checksum, buf[FW_POS_CHECKSUM]);
824	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
825		dev_warn(&ts->client->dev,
826			 "%s: unknown packet type: %02x\n",
827			 __func__, buf[FW_POS_HEADER]);
828	else
829		elants_i2c_mt_event(ts, buf);
830}
831
832static irqreturn_t elants_i2c_irq(int irq, void *_dev)
833{
834	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
835	struct elants_data *ts = _dev;
836	struct i2c_client *client = ts->client;
837	int report_count, report_len;
838	int i;
839	int len;
840
841	len = i2c_master_recv(client, ts->buf, sizeof(ts->buf));
842	if (len < 0) {
843		dev_err(&client->dev, "%s: failed to read data: %d\n",
844			__func__, len);
845		goto out;
846	}
847
848	dev_dbg(&client->dev, "%s: packet %*ph\n",
849		__func__, HEADER_SIZE, ts->buf);
850
851	switch (ts->state) {
852	case ELAN_WAIT_RECALIBRATION:
853		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
854			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
855			complete(&ts->cmd_done);
856			ts->state = ELAN_STATE_NORMAL;
857		}
858		break;
859
860	case ELAN_WAIT_QUEUE_HEADER:
861		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
862			break;
863
864		ts->state = ELAN_STATE_NORMAL;
865		/* fall through */
866
867	case ELAN_STATE_NORMAL:
868
869		switch (ts->buf[FW_HDR_TYPE]) {
870		case CMD_HEADER_HELLO:
871		case CMD_HEADER_RESP:
872		case CMD_HEADER_REK:
873			break;
874
875		case QUEUE_HEADER_WAIT:
876			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
877				dev_err(&client->dev,
878					"invalid wait packet %*ph\n",
879					HEADER_SIZE, ts->buf);
880			} else {
881				ts->state = ELAN_WAIT_QUEUE_HEADER;
882				udelay(30);
883			}
884			break;
885
886		case QUEUE_HEADER_SINGLE:
887			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
888			break;
889
890		case QUEUE_HEADER_NORMAL:
891			report_count = ts->buf[FW_HDR_COUNT];
892			if (report_count > 3) {
893				dev_err(&client->dev,
894					"too large report count: %*ph\n",
895					HEADER_SIZE, ts->buf);
896				break;
897			}
898
899			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
900			if (report_len != PACKET_SIZE) {
901				dev_err(&client->dev,
902					"mismatching report length: %*ph\n",
903					HEADER_SIZE, ts->buf);
904				break;
905			}
906
907			for (i = 0; i < report_count; i++) {
908				u8 *buf = ts->buf + HEADER_SIZE +
909							i * PACKET_SIZE;
910				elants_i2c_event(ts, buf);
911			}
912			break;
913
914		default:
915			dev_err(&client->dev, "unknown packet %*ph\n",
916				HEADER_SIZE, ts->buf);
917			break;
918		}
919		break;
920	}
921
922out:
923	return IRQ_HANDLED;
924}
925
926/*
927 * sysfs interface
928 */
929static ssize_t calibrate_store(struct device *dev,
930			       struct device_attribute *attr,
931			      const char *buf, size_t count)
932{
933	struct i2c_client *client = to_i2c_client(dev);
934	struct elants_data *ts = i2c_get_clientdata(client);
935	int error;
936
937	error = mutex_lock_interruptible(&ts->sysfs_mutex);
938	if (error)
939		return error;
940
941	error = elants_i2c_calibrate(ts);
942
943	mutex_unlock(&ts->sysfs_mutex);
944	return error ?: count;
945}
946
947static ssize_t write_update_fw(struct device *dev,
948			       struct device_attribute *attr,
949			       const char *buf, size_t count)
950{
951	struct i2c_client *client = to_i2c_client(dev);
952	struct elants_data *ts = i2c_get_clientdata(client);
953	int error;
954
955	error = mutex_lock_interruptible(&ts->sysfs_mutex);
956	if (error)
957		return error;
958
959	error = elants_i2c_fw_update(ts);
960	dev_dbg(dev, "firmware update result: %d\n", error);
961
962	mutex_unlock(&ts->sysfs_mutex);
963	return error ?: count;
964}
965
966static ssize_t show_iap_mode(struct device *dev,
967			     struct device_attribute *attr, char *buf)
968{
969	struct i2c_client *client = to_i2c_client(dev);
970	struct elants_data *ts = i2c_get_clientdata(client);
971
972	return sprintf(buf, "%s\n",
973		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
974				"Normal" : "Recovery");
975}
976
977static DEVICE_ATTR(calibrate, S_IWUSR, NULL, calibrate_store);
978static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
979static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
980
981struct elants_version_attribute {
982	struct device_attribute dattr;
983	size_t field_offset;
984	size_t field_size;
985};
986
987#define __ELANTS_FIELD_SIZE(_field)					\
988	sizeof(((struct elants_data *)NULL)->_field)
989#define __ELANTS_VERIFY_SIZE(_field)					\
990	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
991	 __ELANTS_FIELD_SIZE(_field))
992#define ELANTS_VERSION_ATTR(_field)					\
993	struct elants_version_attribute elants_ver_attr_##_field = {	\
994		.dattr = __ATTR(_field, S_IRUGO,			\
995				elants_version_attribute_show, NULL),	\
996		.field_offset = offsetof(struct elants_data, _field),	\
997		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
998	}
999
1000static ssize_t elants_version_attribute_show(struct device *dev,
1001					     struct device_attribute *dattr,
1002					     char *buf)
1003{
1004	struct i2c_client *client = to_i2c_client(dev);
1005	struct elants_data *ts = i2c_get_clientdata(client);
1006	struct elants_version_attribute *attr =
1007		container_of(dattr, struct elants_version_attribute, dattr);
1008	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1009	unsigned int fmt_size;
1010	unsigned int val;
1011
1012	if (attr->field_size == 1) {
1013		val = *field;
1014		fmt_size = 2; /* 2 HEX digits */
1015	} else {
1016		val = *(u16 *)field;
1017		fmt_size = 4; /* 4 HEX digits */
1018	}
1019
1020	return sprintf(buf, "%0*x\n", fmt_size, val);
1021}
1022
1023static ELANTS_VERSION_ATTR(fw_version);
1024static ELANTS_VERSION_ATTR(hw_version);
1025static ELANTS_VERSION_ATTR(test_version);
1026static ELANTS_VERSION_ATTR(solution_version);
1027static ELANTS_VERSION_ATTR(bc_version);
1028static ELANTS_VERSION_ATTR(iap_version);
1029
1030static struct attribute *elants_attributes[] = {
1031	&dev_attr_calibrate.attr,
1032	&dev_attr_update_fw.attr,
1033	&dev_attr_iap_mode.attr,
1034
1035	&elants_ver_attr_fw_version.dattr.attr,
1036	&elants_ver_attr_hw_version.dattr.attr,
1037	&elants_ver_attr_test_version.dattr.attr,
1038	&elants_ver_attr_solution_version.dattr.attr,
1039	&elants_ver_attr_bc_version.dattr.attr,
1040	&elants_ver_attr_iap_version.dattr.attr,
1041	NULL
1042};
1043
1044static struct attribute_group elants_attribute_group = {
1045	.attrs = elants_attributes,
1046};
1047
1048static void elants_i2c_remove_sysfs_group(void *_data)
1049{
1050	struct elants_data *ts = _data;
1051
1052	sysfs_remove_group(&ts->client->dev.kobj, &elants_attribute_group);
1053}
1054
1055static int elants_i2c_probe(struct i2c_client *client,
1056			    const struct i2c_device_id *id)
1057{
1058	union i2c_smbus_data dummy;
1059	struct elants_data *ts;
1060	unsigned long irqflags;
1061	int error;
1062
1063	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1064		dev_err(&client->dev,
1065			"%s: i2c check functionality error\n", DEVICE_NAME);
1066		return -ENXIO;
1067	}
1068
1069	/* Make sure there is something at this address */
1070	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1071			I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1072		dev_err(&client->dev, "nothing at this address\n");
1073		return -ENXIO;
1074	}
1075
1076	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1077	if (!ts)
1078		return -ENOMEM;
1079
1080	mutex_init(&ts->sysfs_mutex);
1081	init_completion(&ts->cmd_done);
1082
1083	ts->client = client;
1084	i2c_set_clientdata(client, ts);
1085
1086	error = elants_i2c_initialize(ts);
1087	if (error) {
1088		dev_err(&client->dev, "failed to initialize: %d\n", error);
1089		return error;
1090	}
1091
1092	ts->input = devm_input_allocate_device(&client->dev);
1093	if (!ts->input) {
1094		dev_err(&client->dev, "Failed to allocate input device\n");
1095		return -ENOMEM;
1096	}
1097
1098	ts->input->name = "Elan Touchscreen";
1099	ts->input->id.bustype = BUS_I2C;
1100
1101	__set_bit(BTN_TOUCH, ts->input->keybit);
1102	__set_bit(EV_ABS, ts->input->evbit);
1103	__set_bit(EV_KEY, ts->input->evbit);
1104
1105	/* Single touch input params setup */
1106	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1107	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1108	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1109	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1110	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1111
1112	/* Multitouch input params setup */
1113	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1114				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1115	if (error) {
1116		dev_err(&client->dev,
1117			"failed to initialize MT slots: %d\n", error);
1118		return error;
1119	}
1120
1121	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1122	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1123	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1124	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1125	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1126	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1127
1128	input_set_drvdata(ts->input, ts);
1129
1130	error = input_register_device(ts->input);
1131	if (error) {
1132		dev_err(&client->dev,
1133			"unable to register input device: %d\n", error);
1134		return error;
1135	}
1136
1137	/*
1138	 * Systems using device tree should set up interrupt via DTS,
1139	 * the rest will use the default falling edge interrupts.
1140	 */
1141	irqflags = client->dev.of_node ? 0 : IRQF_TRIGGER_FALLING;
1142
1143	error = devm_request_threaded_irq(&client->dev, client->irq,
1144					  NULL, elants_i2c_irq,
1145					  irqflags | IRQF_ONESHOT,
1146					  client->name, ts);
1147	if (error) {
1148		dev_err(&client->dev, "Failed to register interrupt\n");
1149		return error;
1150	}
1151
1152	/*
1153	 * Systems using device tree should set up wakeup via DTS,
1154	 * the rest will configure device as wakeup source by default.
1155	 */
1156	if (!client->dev.of_node)
1157		device_init_wakeup(&client->dev, true);
1158
1159	error = sysfs_create_group(&client->dev.kobj, &elants_attribute_group);
1160	if (error) {
1161		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1162			error);
1163		return error;
1164	}
1165
1166	error = devm_add_action(&client->dev,
1167				elants_i2c_remove_sysfs_group, ts);
1168	if (error) {
1169		elants_i2c_remove_sysfs_group(ts);
1170		dev_err(&client->dev,
1171			"Failed to add sysfs cleanup action: %d\n",
1172			error);
1173		return error;
1174	}
1175
1176	return 0;
1177}
1178
1179static int __maybe_unused elants_i2c_suspend(struct device *dev)
1180{
1181	struct i2c_client *client = to_i2c_client(dev);
1182	struct elants_data *ts = i2c_get_clientdata(client);
1183	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1184	int retry_cnt;
1185	int error;
1186
1187	/* Command not support in IAP recovery mode */
1188	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1189		return -EBUSY;
1190
1191	disable_irq(client->irq);
1192
1193	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1194		error = elants_i2c_send(client, set_sleep_cmd,
1195					sizeof(set_sleep_cmd));
1196		if (!error)
1197			break;
1198
1199		dev_err(&client->dev, "suspend command failed: %d\n", error);
1200	}
1201
1202	if (device_may_wakeup(dev))
1203		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1204
1205	return 0;
1206}
1207
1208static int __maybe_unused elants_i2c_resume(struct device *dev)
1209{
1210	struct i2c_client *client = to_i2c_client(dev);
1211	struct elants_data *ts = i2c_get_clientdata(client);
1212	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1213	int retry_cnt;
1214	int error;
1215
1216	if (device_may_wakeup(dev) && ts->wake_irq_enabled)
1217		disable_irq_wake(client->irq);
1218
1219	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1220		error = elants_i2c_send(client, set_active_cmd,
1221					sizeof(set_active_cmd));
1222		if (!error)
1223			break;
1224
1225		dev_err(&client->dev, "resume command failed: %d\n", error);
1226	}
1227
1228	ts->state = ELAN_STATE_NORMAL;
1229	enable_irq(client->irq);
1230
1231	return 0;
1232}
1233
1234static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1235			 elants_i2c_suspend, elants_i2c_resume);
1236
1237static const struct i2c_device_id elants_i2c_id[] = {
1238	{ DEVICE_NAME, 0 },
1239	{ }
1240};
1241MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1242
1243#ifdef CONFIG_ACPI
1244static const struct acpi_device_id elants_acpi_id[] = {
1245	{ "ELAN0001", 0 },
1246	{ }
1247};
1248MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1249#endif
1250
1251#ifdef CONFIG_OF
1252static const struct of_device_id elants_of_match[] = {
1253	{ .compatible = "elan,ekth3500" },
1254	{ /* sentinel */ }
1255};
1256MODULE_DEVICE_TABLE(of, elants_of_match);
1257#endif
1258
1259static struct i2c_driver elants_i2c_driver = {
1260	.probe = elants_i2c_probe,
1261	.id_table = elants_i2c_id,
1262	.driver = {
1263		.name = DEVICE_NAME,
1264		.owner = THIS_MODULE,
1265		.pm = &elants_i2c_pm_ops,
1266		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1267		.of_match_table = of_match_ptr(elants_of_match),
1268	},
1269};
1270module_i2c_driver(elants_i2c_driver);
1271
1272MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1273MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1274MODULE_VERSION(DRV_VERSION);
1275MODULE_LICENSE("GPL");
1276