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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Elan Microelectronics touch panels with I2C interface
4  *
5  * Copyright (C) 2014 Elan Microelectronics Corporation.
6  * Scott Liu <scott.liu@emc.com.tw>
7  *
8  * This code is partly based on hid-multitouch.c:
9  *
10  *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
11  *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
12  *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
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 #include <linux/module.h>
23 #include <linux/input.h>
24 #include <linux/interrupt.h>
25 #include <linux/irq.h>
26 #include <linux/platform_device.h>
27 #include <linux/async.h>
28 #include <linux/i2c.h>
29 #include <linux/delay.h>
30 #include <linux/uaccess.h>
31 #include <linux/buffer_head.h>
32 #include <linux/slab.h>
33 #include <linux/firmware.h>
34 #include <linux/input/mt.h>
35 #include <linux/acpi.h>
36 #include <linux/of.h>
37 #include <linux/gpio/consumer.h>
38 #include <linux/regulator/consumer.h>
39 #include <linux/uuid.h>
40 #include <asm/unaligned.h>
41 
42 /* Device, Driver information */
43 #define DEVICE_NAME	"elants_i2c"
44 
45 /* Convert from rows or columns into resolution */
46 #define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
47 
48 /* FW header data */
49 #define HEADER_SIZE		4
50 #define FW_HDR_TYPE		0
51 #define FW_HDR_COUNT		1
52 #define FW_HDR_LENGTH		2
53 
54 /* Buffer mode Queue Header information */
55 #define QUEUE_HEADER_SINGLE	0x62
56 #define QUEUE_HEADER_NORMAL	0X63
57 #define QUEUE_HEADER_WAIT	0x64
58 
59 /* Command header definition */
60 #define CMD_HEADER_WRITE	0x54
61 #define CMD_HEADER_READ		0x53
62 #define CMD_HEADER_6B_READ	0x5B
63 #define CMD_HEADER_RESP		0x52
64 #define CMD_HEADER_6B_RESP	0x9B
65 #define CMD_HEADER_HELLO	0x55
66 #define CMD_HEADER_REK		0x66
67 
68 /* FW position data */
69 #define PACKET_SIZE		55
70 #define MAX_CONTACT_NUM		10
71 #define FW_POS_HEADER		0
72 #define FW_POS_STATE		1
73 #define FW_POS_TOTAL		2
74 #define FW_POS_XY		3
75 #define FW_POS_CHECKSUM		34
76 #define FW_POS_WIDTH		35
77 #define FW_POS_PRESSURE		45
78 
79 #define HEADER_REPORT_10_FINGER	0x62
80 
81 /* Header (4 bytes) plus 3 fill 10-finger packets */
82 #define MAX_PACKET_SIZE		169
83 
84 #define BOOT_TIME_DELAY_MS	50
85 
86 /* FW read command, 0x53 0x?? 0x0, 0x01 */
87 #define E_ELAN_INFO_FW_VER	0x00
88 #define E_ELAN_INFO_BC_VER	0x10
89 #define E_ELAN_INFO_TEST_VER	0xE0
90 #define E_ELAN_INFO_FW_ID	0xF0
91 #define E_INFO_OSR		0xD6
92 #define E_INFO_PHY_SCAN		0xD7
93 #define E_INFO_PHY_DRIVER	0xD8
94 
95 #define MAX_RETRIES		3
96 #define MAX_FW_UPDATE_RETRIES	30
97 
98 #define ELAN_FW_PAGESIZE	132
99 
100 /* calibration timeout definition */
101 #define ELAN_CALI_TIMEOUT_MSEC	12000
102 
103 #define ELAN_POWERON_DELAY_USEC	500
104 #define ELAN_RESET_DELAY_MSEC	20
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 	struct regulator *vcc33;
123 	struct regulator *vccio;
124 	struct gpio_desc *reset_gpio;
125 
126 	u16 fw_version;
127 	u8 test_version;
128 	u8 solution_version;
129 	u8 bc_version;
130 	u8 iap_version;
131 	u16 hw_version;
132 	unsigned int x_res;	/* resolution in units/mm */
133 	unsigned int y_res;
134 	unsigned int x_max;
135 	unsigned int y_max;
136 
137 	enum elants_state state;
138 	enum elants_iap_mode iap_mode;
139 
140 	/* Guards against concurrent access to the device via sysfs */
141 	struct mutex sysfs_mutex;
142 
143 	u8 cmd_resp[HEADER_SIZE];
144 	struct completion cmd_done;
145 
146 	bool wake_irq_enabled;
147 	bool keep_power_in_suspend;
148 
149 	/* Must be last to be used for DMA operations */
150 	u8 buf[MAX_PACKET_SIZE] ____cacheline_aligned;
151 };
152 
elants_i2c_send(struct i2c_client * client,const void * data,size_t size)153 static int elants_i2c_send(struct i2c_client *client,
154 			   const void *data, size_t size)
155 {
156 	int ret;
157 
158 	ret = i2c_master_send(client, data, size);
159 	if (ret == size)
160 		return 0;
161 
162 	if (ret >= 0)
163 		ret = -EIO;
164 
165 	dev_err(&client->dev, "%s failed (%*ph): %d\n",
166 		__func__, (int)size, data, ret);
167 
168 	return ret;
169 }
170 
elants_i2c_read(struct i2c_client * client,void * data,size_t size)171 static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
172 {
173 	int ret;
174 
175 	ret = i2c_master_recv(client, data, size);
176 	if (ret == size)
177 		return 0;
178 
179 	if (ret >= 0)
180 		ret = -EIO;
181 
182 	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
183 
184 	return ret;
185 }
186 
elants_i2c_execute_command(struct i2c_client * client,const u8 * cmd,size_t cmd_size,u8 * resp,size_t resp_size)187 static int elants_i2c_execute_command(struct i2c_client *client,
188 				      const u8 *cmd, size_t cmd_size,
189 				      u8 *resp, size_t resp_size)
190 {
191 	struct i2c_msg msgs[2];
192 	int ret;
193 	u8 expected_response;
194 
195 	switch (cmd[0]) {
196 	case CMD_HEADER_READ:
197 		expected_response = CMD_HEADER_RESP;
198 		break;
199 
200 	case CMD_HEADER_6B_READ:
201 		expected_response = CMD_HEADER_6B_RESP;
202 		break;
203 
204 	default:
205 		dev_err(&client->dev, "%s: invalid command %*ph\n",
206 			__func__, (int)cmd_size, cmd);
207 		return -EINVAL;
208 	}
209 
210 	msgs[0].addr = client->addr;
211 	msgs[0].flags = client->flags & I2C_M_TEN;
212 	msgs[0].len = cmd_size;
213 	msgs[0].buf = (u8 *)cmd;
214 
215 	msgs[1].addr = client->addr;
216 	msgs[1].flags = client->flags & I2C_M_TEN;
217 	msgs[1].flags |= I2C_M_RD;
218 	msgs[1].len = resp_size;
219 	msgs[1].buf = resp;
220 
221 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
222 	if (ret < 0)
223 		return ret;
224 
225 	if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
226 		return -EIO;
227 
228 	return 0;
229 }
230 
elants_i2c_calibrate(struct elants_data * ts)231 static int elants_i2c_calibrate(struct elants_data *ts)
232 {
233 	struct i2c_client *client = ts->client;
234 	int ret, error;
235 	static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
236 	static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
237 	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
238 
239 	disable_irq(client->irq);
240 
241 	ts->state = ELAN_WAIT_RECALIBRATION;
242 	reinit_completion(&ts->cmd_done);
243 
244 	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
245 	elants_i2c_send(client, rek, sizeof(rek));
246 
247 	enable_irq(client->irq);
248 
249 	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
250 				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
251 
252 	ts->state = ELAN_STATE_NORMAL;
253 
254 	if (ret <= 0) {
255 		error = ret < 0 ? ret : -ETIMEDOUT;
256 		dev_err(&client->dev,
257 			"error while waiting for calibration to complete: %d\n",
258 			error);
259 		return error;
260 	}
261 
262 	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
263 		dev_err(&client->dev,
264 			"unexpected calibration response: %*ph\n",
265 			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
266 		return -EINVAL;
267 	}
268 
269 	return 0;
270 }
271 
elants_i2c_sw_reset(struct i2c_client * client)272 static int elants_i2c_sw_reset(struct i2c_client *client)
273 {
274 	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
275 	int error;
276 
277 	error = elants_i2c_send(client, soft_rst_cmd,
278 				sizeof(soft_rst_cmd));
279 	if (error) {
280 		dev_err(&client->dev, "software reset failed: %d\n", error);
281 		return error;
282 	}
283 
284 	/*
285 	 * We should wait at least 10 msec (but no more than 40) before
286 	 * sending fastboot or IAP command to the device.
287 	 */
288 	msleep(30);
289 
290 	return 0;
291 }
292 
elants_i2c_parse_version(u8 * buf)293 static u16 elants_i2c_parse_version(u8 *buf)
294 {
295 	return get_unaligned_be32(buf) >> 4;
296 }
297 
elants_i2c_query_hw_version(struct elants_data * ts)298 static int elants_i2c_query_hw_version(struct elants_data *ts)
299 {
300 	struct i2c_client *client = ts->client;
301 	int error, retry_cnt;
302 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
303 	u8 resp[HEADER_SIZE];
304 
305 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
306 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
307 						   resp, sizeof(resp));
308 		if (!error) {
309 			ts->hw_version = elants_i2c_parse_version(resp);
310 			if (ts->hw_version != 0xffff)
311 				return 0;
312 		}
313 
314 		dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
315 			error, (int)sizeof(resp), resp);
316 	}
317 
318 	if (error) {
319 		dev_err(&client->dev,
320 			"Failed to read fw id: %d\n", error);
321 		return error;
322 	}
323 
324 	dev_err(&client->dev, "Invalid fw id: %#04x\n", ts->hw_version);
325 
326 	return -EINVAL;
327 }
328 
elants_i2c_query_fw_version(struct elants_data * ts)329 static int elants_i2c_query_fw_version(struct elants_data *ts)
330 {
331 	struct i2c_client *client = ts->client;
332 	int error, retry_cnt;
333 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
334 	u8 resp[HEADER_SIZE];
335 
336 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
337 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
338 						   resp, sizeof(resp));
339 		if (!error) {
340 			ts->fw_version = elants_i2c_parse_version(resp);
341 			if (ts->fw_version != 0x0000 &&
342 			    ts->fw_version != 0xffff)
343 				return 0;
344 		}
345 
346 		dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
347 			error, (int)sizeof(resp), resp);
348 	}
349 
350 	dev_err(&client->dev,
351 		"Failed to read fw version or fw version is invalid\n");
352 
353 	return -EINVAL;
354 }
355 
elants_i2c_query_test_version(struct elants_data * ts)356 static int elants_i2c_query_test_version(struct elants_data *ts)
357 {
358 	struct i2c_client *client = ts->client;
359 	int error, retry_cnt;
360 	u16 version;
361 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
362 	u8 resp[HEADER_SIZE];
363 
364 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
365 		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
366 						   resp, sizeof(resp));
367 		if (!error) {
368 			version = elants_i2c_parse_version(resp);
369 			ts->test_version = version >> 8;
370 			ts->solution_version = version & 0xff;
371 
372 			return 0;
373 		}
374 
375 		dev_dbg(&client->dev,
376 			"read test version error rc=%d, buf=%*phC\n",
377 			error, (int)sizeof(resp), resp);
378 	}
379 
380 	dev_err(&client->dev, "Failed to read test version\n");
381 
382 	return -EINVAL;
383 }
384 
elants_i2c_query_bc_version(struct elants_data * ts)385 static int elants_i2c_query_bc_version(struct elants_data *ts)
386 {
387 	struct i2c_client *client = ts->client;
388 	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
389 	u8 resp[HEADER_SIZE];
390 	u16 version;
391 	int error;
392 
393 	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
394 					   resp, sizeof(resp));
395 	if (error) {
396 		dev_err(&client->dev,
397 			"read BC version error=%d, buf=%*phC\n",
398 			error, (int)sizeof(resp), resp);
399 		return error;
400 	}
401 
402 	version = elants_i2c_parse_version(resp);
403 	ts->bc_version = version >> 8;
404 	ts->iap_version = version & 0xff;
405 
406 	return 0;
407 }
408 
elants_i2c_query_ts_info(struct elants_data * ts)409 static int elants_i2c_query_ts_info(struct elants_data *ts)
410 {
411 	struct i2c_client *client = ts->client;
412 	int error;
413 	u8 resp[17];
414 	u16 phy_x, phy_y, rows, cols, osr;
415 	const u8 get_resolution_cmd[] = {
416 		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
417 	};
418 	const u8 get_osr_cmd[] = {
419 		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
420 	};
421 	const u8 get_physical_scan_cmd[] = {
422 		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
423 	};
424 	const u8 get_physical_drive_cmd[] = {
425 		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
426 	};
427 
428 	/* Get trace number */
429 	error = elants_i2c_execute_command(client,
430 					   get_resolution_cmd,
431 					   sizeof(get_resolution_cmd),
432 					   resp, sizeof(resp));
433 	if (error) {
434 		dev_err(&client->dev, "get resolution command failed: %d\n",
435 			error);
436 		return error;
437 	}
438 
439 	rows = resp[2] + resp[6] + resp[10];
440 	cols = resp[3] + resp[7] + resp[11];
441 
442 	/* Process mm_to_pixel information */
443 	error = elants_i2c_execute_command(client,
444 					   get_osr_cmd, sizeof(get_osr_cmd),
445 					   resp, sizeof(resp));
446 	if (error) {
447 		dev_err(&client->dev, "get osr command failed: %d\n",
448 			error);
449 		return error;
450 	}
451 
452 	osr = resp[3];
453 
454 	error = elants_i2c_execute_command(client,
455 					   get_physical_scan_cmd,
456 					   sizeof(get_physical_scan_cmd),
457 					   resp, sizeof(resp));
458 	if (error) {
459 		dev_err(&client->dev, "get physical scan command failed: %d\n",
460 			error);
461 		return error;
462 	}
463 
464 	phy_x = get_unaligned_be16(&resp[2]);
465 
466 	error = elants_i2c_execute_command(client,
467 					   get_physical_drive_cmd,
468 					   sizeof(get_physical_drive_cmd),
469 					   resp, sizeof(resp));
470 	if (error) {
471 		dev_err(&client->dev, "get physical drive command failed: %d\n",
472 			error);
473 		return error;
474 	}
475 
476 	phy_y = get_unaligned_be16(&resp[2]);
477 
478 	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
479 
480 	if (rows == 0 || cols == 0 || osr == 0) {
481 		dev_warn(&client->dev,
482 			 "invalid trace number data: %d, %d, %d\n",
483 			 rows, cols, osr);
484 	} else {
485 		/* translate trace number to TS resolution */
486 		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
487 		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
488 		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
489 		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
490 	}
491 
492 	return 0;
493 }
494 
elants_i2c_fastboot(struct i2c_client * client)495 static int elants_i2c_fastboot(struct i2c_client *client)
496 {
497 	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
498 	int error;
499 
500 	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
501 	if (error) {
502 		dev_err(&client->dev, "boot failed: %d\n", error);
503 		return error;
504 	}
505 
506 	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
507 	return 0;
508 }
509 
elants_i2c_initialize(struct elants_data * ts)510 static int elants_i2c_initialize(struct elants_data *ts)
511 {
512 	struct i2c_client *client = ts->client;
513 	int error, error2, retry_cnt;
514 	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
515 	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
516 	u8 buf[HEADER_SIZE];
517 
518 	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
519 		error = elants_i2c_sw_reset(client);
520 		if (error) {
521 			/* Continue initializing if it's the last try */
522 			if (retry_cnt < MAX_RETRIES - 1)
523 				continue;
524 		}
525 
526 		error = elants_i2c_fastboot(client);
527 		if (error) {
528 			/* Continue initializing if it's the last try */
529 			if (retry_cnt < MAX_RETRIES - 1)
530 				continue;
531 		}
532 
533 		/* Wait for Hello packet */
534 		msleep(BOOT_TIME_DELAY_MS);
535 
536 		error = elants_i2c_read(client, buf, sizeof(buf));
537 		if (error) {
538 			dev_err(&client->dev,
539 				"failed to read 'hello' packet: %d\n", error);
540 		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
541 			ts->iap_mode = ELAN_IAP_OPERATIONAL;
542 			break;
543 		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
544 			/*
545 			 * Setting error code will mark device
546 			 * in recovery mode below.
547 			 */
548 			error = -EIO;
549 			break;
550 		} else {
551 			error = -EINVAL;
552 			dev_err(&client->dev,
553 				"invalid 'hello' packet: %*ph\n",
554 				(int)sizeof(buf), buf);
555 		}
556 	}
557 
558 	/* hw version is available even if device in recovery state */
559 	error2 = elants_i2c_query_hw_version(ts);
560 	if (!error)
561 		error = error2;
562 
563 	if (!error)
564 		error = elants_i2c_query_fw_version(ts);
565 	if (!error)
566 		error = elants_i2c_query_test_version(ts);
567 	if (!error)
568 		error = elants_i2c_query_bc_version(ts);
569 	if (!error)
570 		error = elants_i2c_query_ts_info(ts);
571 
572 	if (error)
573 		ts->iap_mode = ELAN_IAP_RECOVERY;
574 
575 	return 0;
576 }
577 
578 /*
579  * Firmware update interface.
580  */
581 
elants_i2c_fw_write_page(struct i2c_client * client,const void * page)582 static int elants_i2c_fw_write_page(struct i2c_client *client,
583 				    const void *page)
584 {
585 	const u8 ack_ok[] = { 0xaa, 0xaa };
586 	u8 buf[2];
587 	int retry;
588 	int error;
589 
590 	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
591 		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
592 		if (error) {
593 			dev_err(&client->dev,
594 				"IAP Write Page failed: %d\n", error);
595 			continue;
596 		}
597 
598 		error = elants_i2c_read(client, buf, 2);
599 		if (error) {
600 			dev_err(&client->dev,
601 				"IAP Ack read failed: %d\n", error);
602 			return error;
603 		}
604 
605 		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
606 			return 0;
607 
608 		error = -EIO;
609 		dev_err(&client->dev,
610 			"IAP Get Ack Error [%02x:%02x]\n",
611 			buf[0], buf[1]);
612 	}
613 
614 	return error;
615 }
616 
elants_i2c_do_update_firmware(struct i2c_client * client,const struct firmware * fw,bool force)617 static int elants_i2c_do_update_firmware(struct i2c_client *client,
618 					 const struct firmware *fw,
619 					 bool force)
620 {
621 	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
622 	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
623 	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
624 	const u8 close_idle[] = {0x54, 0x2c, 0x01, 0x01};
625 	u8 buf[HEADER_SIZE];
626 	u16 send_id;
627 	int page, n_fw_pages;
628 	int error;
629 
630 	/* Recovery mode detection! */
631 	if (force) {
632 		dev_dbg(&client->dev, "Recovery mode procedure\n");
633 		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
634 	} else {
635 		/* Start IAP Procedure */
636 		dev_dbg(&client->dev, "Normal IAP procedure\n");
637 		/* Close idle mode */
638 		error = elants_i2c_send(client, close_idle, sizeof(close_idle));
639 		if (error)
640 			dev_err(&client->dev, "Failed close idle: %d\n", error);
641 		msleep(60);
642 		elants_i2c_sw_reset(client);
643 		msleep(20);
644 		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
645 	}
646 
647 	if (error) {
648 		dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
649 		return error;
650 	}
651 
652 	msleep(20);
653 
654 	/* check IAP state */
655 	error = elants_i2c_read(client, buf, 4);
656 	if (error) {
657 		dev_err(&client->dev,
658 			"failed to read IAP acknowledgement: %d\n",
659 			error);
660 		return error;
661 	}
662 
663 	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
664 		dev_err(&client->dev,
665 			"failed to enter IAP: %*ph (expected %*ph)\n",
666 			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
667 		return -EIO;
668 	}
669 
670 	dev_info(&client->dev, "successfully entered IAP mode");
671 
672 	send_id = client->addr;
673 	error = elants_i2c_send(client, &send_id, 1);
674 	if (error) {
675 		dev_err(&client->dev, "sending dummy byte failed: %d\n",
676 			error);
677 		return error;
678 	}
679 
680 	/* Clear the last page of Master */
681 	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
682 	if (error) {
683 		dev_err(&client->dev, "clearing of the last page failed: %d\n",
684 			error);
685 		return error;
686 	}
687 
688 	error = elants_i2c_read(client, buf, 2);
689 	if (error) {
690 		dev_err(&client->dev,
691 			"failed to read ACK for clearing the last page: %d\n",
692 			error);
693 		return error;
694 	}
695 
696 	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
697 	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
698 
699 	for (page = 0; page < n_fw_pages; page++) {
700 		error = elants_i2c_fw_write_page(client,
701 					fw->data + page * ELAN_FW_PAGESIZE);
702 		if (error) {
703 			dev_err(&client->dev,
704 				"failed to write FW page %d: %d\n",
705 				page, error);
706 			return error;
707 		}
708 	}
709 
710 	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
711 	msleep(300);
712 
713 	dev_info(&client->dev, "firmware update completed\n");
714 	return 0;
715 }
716 
elants_i2c_fw_update(struct elants_data * ts)717 static int elants_i2c_fw_update(struct elants_data *ts)
718 {
719 	struct i2c_client *client = ts->client;
720 	const struct firmware *fw;
721 	char *fw_name;
722 	int error;
723 
724 	fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
725 	if (!fw_name)
726 		return -ENOMEM;
727 
728 	dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
729 	error = request_firmware(&fw, fw_name, &client->dev);
730 	kfree(fw_name);
731 	if (error) {
732 		dev_err(&client->dev, "failed to request firmware: %d\n",
733 			error);
734 		return error;
735 	}
736 
737 	if (fw->size % ELAN_FW_PAGESIZE) {
738 		dev_err(&client->dev, "invalid firmware length: %zu\n",
739 			fw->size);
740 		error = -EINVAL;
741 		goto out;
742 	}
743 
744 	disable_irq(client->irq);
745 
746 	error = elants_i2c_do_update_firmware(client, fw,
747 					ts->iap_mode == ELAN_IAP_RECOVERY);
748 	if (error) {
749 		dev_err(&client->dev, "firmware update failed: %d\n", error);
750 		ts->iap_mode = ELAN_IAP_RECOVERY;
751 		goto out_enable_irq;
752 	}
753 
754 	error = elants_i2c_initialize(ts);
755 	if (error) {
756 		dev_err(&client->dev,
757 			"failed to initialize device after firmware update: %d\n",
758 			error);
759 		ts->iap_mode = ELAN_IAP_RECOVERY;
760 		goto out_enable_irq;
761 	}
762 
763 	ts->iap_mode = ELAN_IAP_OPERATIONAL;
764 
765 out_enable_irq:
766 	ts->state = ELAN_STATE_NORMAL;
767 	enable_irq(client->irq);
768 	msleep(100);
769 
770 	if (!error)
771 		elants_i2c_calibrate(ts);
772 out:
773 	release_firmware(fw);
774 	return error;
775 }
776 
777 /*
778  * Event reporting.
779  */
780 
elants_i2c_mt_event(struct elants_data * ts,u8 * buf)781 static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
782 {
783 	struct input_dev *input = ts->input;
784 	unsigned int n_fingers;
785 	u16 finger_state;
786 	int i;
787 
788 	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
789 	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
790 			buf[FW_POS_STATE];
791 
792 	dev_dbg(&ts->client->dev,
793 		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
794 
795 	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
796 		if (finger_state & 1) {
797 			unsigned int x, y, p, w;
798 			u8 *pos;
799 
800 			pos = &buf[FW_POS_XY + i * 3];
801 			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
802 			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
803 			p = buf[FW_POS_PRESSURE + i];
804 			w = buf[FW_POS_WIDTH + i];
805 
806 			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
807 				i, x, y, p, w);
808 
809 			input_mt_slot(input, i);
810 			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
811 			input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
812 			input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
813 			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
814 			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
815 
816 			n_fingers--;
817 		}
818 
819 		finger_state >>= 1;
820 	}
821 
822 	input_mt_sync_frame(input);
823 	input_sync(input);
824 }
825 
elants_i2c_calculate_checksum(u8 * buf)826 static u8 elants_i2c_calculate_checksum(u8 *buf)
827 {
828 	u8 checksum = 0;
829 	u8 i;
830 
831 	for (i = 0; i < FW_POS_CHECKSUM; i++)
832 		checksum += buf[i];
833 
834 	return checksum;
835 }
836 
elants_i2c_event(struct elants_data * ts,u8 * buf)837 static void elants_i2c_event(struct elants_data *ts, u8 *buf)
838 {
839 	u8 checksum = elants_i2c_calculate_checksum(buf);
840 
841 	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
842 		dev_warn(&ts->client->dev,
843 			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
844 			 __func__, buf[FW_POS_HEADER],
845 			 checksum, buf[FW_POS_CHECKSUM]);
846 	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
847 		dev_warn(&ts->client->dev,
848 			 "%s: unknown packet type: %02x\n",
849 			 __func__, buf[FW_POS_HEADER]);
850 	else
851 		elants_i2c_mt_event(ts, buf);
852 }
853 
elants_i2c_irq(int irq,void * _dev)854 static irqreturn_t elants_i2c_irq(int irq, void *_dev)
855 {
856 	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
857 	struct elants_data *ts = _dev;
858 	struct i2c_client *client = ts->client;
859 	int report_count, report_len;
860 	int i;
861 	int len;
862 
863 	len = i2c_master_recv_dmasafe(client, ts->buf, sizeof(ts->buf));
864 	if (len < 0) {
865 		dev_err(&client->dev, "%s: failed to read data: %d\n",
866 			__func__, len);
867 		goto out;
868 	}
869 
870 	dev_dbg(&client->dev, "%s: packet %*ph\n",
871 		__func__, HEADER_SIZE, ts->buf);
872 
873 	switch (ts->state) {
874 	case ELAN_WAIT_RECALIBRATION:
875 		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
876 			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
877 			complete(&ts->cmd_done);
878 			ts->state = ELAN_STATE_NORMAL;
879 		}
880 		break;
881 
882 	case ELAN_WAIT_QUEUE_HEADER:
883 		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
884 			break;
885 
886 		ts->state = ELAN_STATE_NORMAL;
887 		/* fall through */
888 
889 	case ELAN_STATE_NORMAL:
890 
891 		switch (ts->buf[FW_HDR_TYPE]) {
892 		case CMD_HEADER_HELLO:
893 		case CMD_HEADER_RESP:
894 		case CMD_HEADER_REK:
895 			break;
896 
897 		case QUEUE_HEADER_WAIT:
898 			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
899 				dev_err(&client->dev,
900 					"invalid wait packet %*ph\n",
901 					HEADER_SIZE, ts->buf);
902 			} else {
903 				ts->state = ELAN_WAIT_QUEUE_HEADER;
904 				udelay(30);
905 			}
906 			break;
907 
908 		case QUEUE_HEADER_SINGLE:
909 			elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
910 			break;
911 
912 		case QUEUE_HEADER_NORMAL:
913 			report_count = ts->buf[FW_HDR_COUNT];
914 			if (report_count == 0 || report_count > 3) {
915 				dev_err(&client->dev,
916 					"bad report count: %*ph\n",
917 					HEADER_SIZE, ts->buf);
918 				break;
919 			}
920 
921 			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
922 			if (report_len != PACKET_SIZE) {
923 				dev_err(&client->dev,
924 					"mismatching report length: %*ph\n",
925 					HEADER_SIZE, ts->buf);
926 				break;
927 			}
928 
929 			for (i = 0; i < report_count; i++) {
930 				u8 *buf = ts->buf + HEADER_SIZE +
931 							i * PACKET_SIZE;
932 				elants_i2c_event(ts, buf);
933 			}
934 			break;
935 
936 		default:
937 			dev_err(&client->dev, "unknown packet %*ph\n",
938 				HEADER_SIZE, ts->buf);
939 			break;
940 		}
941 		break;
942 	}
943 
944 out:
945 	return IRQ_HANDLED;
946 }
947 
948 /*
949  * sysfs interface
950  */
calibrate_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)951 static ssize_t calibrate_store(struct device *dev,
952 			       struct device_attribute *attr,
953 			      const char *buf, size_t count)
954 {
955 	struct i2c_client *client = to_i2c_client(dev);
956 	struct elants_data *ts = i2c_get_clientdata(client);
957 	int error;
958 
959 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
960 	if (error)
961 		return error;
962 
963 	error = elants_i2c_calibrate(ts);
964 
965 	mutex_unlock(&ts->sysfs_mutex);
966 	return error ?: count;
967 }
968 
write_update_fw(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)969 static ssize_t write_update_fw(struct device *dev,
970 			       struct device_attribute *attr,
971 			       const char *buf, size_t count)
972 {
973 	struct i2c_client *client = to_i2c_client(dev);
974 	struct elants_data *ts = i2c_get_clientdata(client);
975 	int error;
976 
977 	error = mutex_lock_interruptible(&ts->sysfs_mutex);
978 	if (error)
979 		return error;
980 
981 	error = elants_i2c_fw_update(ts);
982 	dev_dbg(dev, "firmware update result: %d\n", error);
983 
984 	mutex_unlock(&ts->sysfs_mutex);
985 	return error ?: count;
986 }
987 
show_iap_mode(struct device * dev,struct device_attribute * attr,char * buf)988 static ssize_t show_iap_mode(struct device *dev,
989 			     struct device_attribute *attr, char *buf)
990 {
991 	struct i2c_client *client = to_i2c_client(dev);
992 	struct elants_data *ts = i2c_get_clientdata(client);
993 
994 	return sprintf(buf, "%s\n",
995 		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
996 				"Normal" : "Recovery");
997 }
998 
999 static DEVICE_ATTR_WO(calibrate);
1000 static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
1001 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
1002 
1003 struct elants_version_attribute {
1004 	struct device_attribute dattr;
1005 	size_t field_offset;
1006 	size_t field_size;
1007 };
1008 
1009 #define __ELANTS_FIELD_SIZE(_field)					\
1010 	sizeof(((struct elants_data *)NULL)->_field)
1011 #define __ELANTS_VERIFY_SIZE(_field)					\
1012 	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
1013 	 __ELANTS_FIELD_SIZE(_field))
1014 #define ELANTS_VERSION_ATTR(_field)					\
1015 	struct elants_version_attribute elants_ver_attr_##_field = {	\
1016 		.dattr = __ATTR(_field, S_IRUGO,			\
1017 				elants_version_attribute_show, NULL),	\
1018 		.field_offset = offsetof(struct elants_data, _field),	\
1019 		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
1020 	}
1021 
elants_version_attribute_show(struct device * dev,struct device_attribute * dattr,char * buf)1022 static ssize_t elants_version_attribute_show(struct device *dev,
1023 					     struct device_attribute *dattr,
1024 					     char *buf)
1025 {
1026 	struct i2c_client *client = to_i2c_client(dev);
1027 	struct elants_data *ts = i2c_get_clientdata(client);
1028 	struct elants_version_attribute *attr =
1029 		container_of(dattr, struct elants_version_attribute, dattr);
1030 	u8 *field = (u8 *)((char *)ts + attr->field_offset);
1031 	unsigned int fmt_size;
1032 	unsigned int val;
1033 
1034 	if (attr->field_size == 1) {
1035 		val = *field;
1036 		fmt_size = 2; /* 2 HEX digits */
1037 	} else {
1038 		val = *(u16 *)field;
1039 		fmt_size = 4; /* 4 HEX digits */
1040 	}
1041 
1042 	return sprintf(buf, "%0*x\n", fmt_size, val);
1043 }
1044 
1045 static ELANTS_VERSION_ATTR(fw_version);
1046 static ELANTS_VERSION_ATTR(hw_version);
1047 static ELANTS_VERSION_ATTR(test_version);
1048 static ELANTS_VERSION_ATTR(solution_version);
1049 static ELANTS_VERSION_ATTR(bc_version);
1050 static ELANTS_VERSION_ATTR(iap_version);
1051 
1052 static struct attribute *elants_attributes[] = {
1053 	&dev_attr_calibrate.attr,
1054 	&dev_attr_update_fw.attr,
1055 	&dev_attr_iap_mode.attr,
1056 
1057 	&elants_ver_attr_fw_version.dattr.attr,
1058 	&elants_ver_attr_hw_version.dattr.attr,
1059 	&elants_ver_attr_test_version.dattr.attr,
1060 	&elants_ver_attr_solution_version.dattr.attr,
1061 	&elants_ver_attr_bc_version.dattr.attr,
1062 	&elants_ver_attr_iap_version.dattr.attr,
1063 	NULL
1064 };
1065 
1066 static const struct attribute_group elants_attribute_group = {
1067 	.attrs = elants_attributes,
1068 };
1069 
elants_i2c_power_on(struct elants_data * ts)1070 static int elants_i2c_power_on(struct elants_data *ts)
1071 {
1072 	int error;
1073 
1074 	/*
1075 	 * If we do not have reset gpio assume platform firmware
1076 	 * controls regulators and does power them on for us.
1077 	 */
1078 	if (IS_ERR_OR_NULL(ts->reset_gpio))
1079 		return 0;
1080 
1081 	error = regulator_enable(ts->vcc33);
1082 	if (error) {
1083 		dev_err(&ts->client->dev,
1084 			"failed to enable vcc33 regulator: %d\n",
1085 			error);
1086 		return error;
1087 	}
1088 
1089 	error = regulator_enable(ts->vccio);
1090 	if (error) {
1091 		dev_err(&ts->client->dev,
1092 			"failed to enable vccio regulator: %d\n",
1093 			error);
1094 		regulator_disable(ts->vcc33);
1095 		return error;
1096 	}
1097 
1098 	/*
1099 	 * We need to wait a bit after powering on controller before
1100 	 * we are allowed to release reset GPIO.
1101 	 */
1102 	udelay(ELAN_POWERON_DELAY_USEC);
1103 
1104 	gpiod_set_value_cansleep(ts->reset_gpio, 0);
1105 	if (error)
1106 		return error;
1107 
1108 	msleep(ELAN_RESET_DELAY_MSEC);
1109 
1110 	return 0;
1111 }
1112 
elants_i2c_power_off(void * _data)1113 static void elants_i2c_power_off(void *_data)
1114 {
1115 	struct elants_data *ts = _data;
1116 
1117 	if (!IS_ERR_OR_NULL(ts->reset_gpio)) {
1118 		/*
1119 		 * Activate reset gpio to prevent leakage through the
1120 		 * pin once we shut off power to the controller.
1121 		 */
1122 		gpiod_set_value_cansleep(ts->reset_gpio, 1);
1123 		regulator_disable(ts->vccio);
1124 		regulator_disable(ts->vcc33);
1125 	}
1126 }
1127 
1128 #ifdef CONFIG_ACPI
1129 static const struct acpi_device_id i2c_hid_ids[] = {
1130 	{"ACPI0C50", 0 },
1131 	{"PNP0C50", 0 },
1132 	{ },
1133 };
1134 
1135 static const guid_t i2c_hid_guid =
1136 	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
1137 		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
1138 
elants_acpi_is_hid_device(struct device * dev)1139 static bool elants_acpi_is_hid_device(struct device *dev)
1140 {
1141 	acpi_handle handle = ACPI_HANDLE(dev);
1142 	union acpi_object *obj;
1143 
1144 	if (acpi_match_device_ids(ACPI_COMPANION(dev), i2c_hid_ids))
1145 		return false;
1146 
1147 	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, ACPI_TYPE_INTEGER);
1148 	if (obj) {
1149 		ACPI_FREE(obj);
1150 		return true;
1151 	}
1152 
1153 	return false;
1154 }
1155 #else
elants_acpi_is_hid_device(struct device * dev)1156 static bool elants_acpi_is_hid_device(struct device *dev)
1157 {
1158 	return false;
1159 }
1160 #endif
1161 
elants_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)1162 static int elants_i2c_probe(struct i2c_client *client,
1163 			    const struct i2c_device_id *id)
1164 {
1165 	union i2c_smbus_data dummy;
1166 	struct elants_data *ts;
1167 	unsigned long irqflags;
1168 	int error;
1169 
1170 	/* Don't bind to i2c-hid compatible devices, these are handled by the i2c-hid drv. */
1171 	if (elants_acpi_is_hid_device(&client->dev)) {
1172 		dev_warn(&client->dev, "This device appears to be an I2C-HID device, not binding\n");
1173 		return -ENODEV;
1174 	}
1175 
1176 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1177 		dev_err(&client->dev, "I2C check functionality error\n");
1178 		return -ENXIO;
1179 	}
1180 
1181 	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1182 	if (!ts)
1183 		return -ENOMEM;
1184 
1185 	mutex_init(&ts->sysfs_mutex);
1186 	init_completion(&ts->cmd_done);
1187 
1188 	ts->client = client;
1189 	i2c_set_clientdata(client, ts);
1190 
1191 	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
1192 	if (IS_ERR(ts->vcc33)) {
1193 		error = PTR_ERR(ts->vcc33);
1194 		if (error != -EPROBE_DEFER)
1195 			dev_err(&client->dev,
1196 				"Failed to get 'vcc33' regulator: %d\n",
1197 				error);
1198 		return error;
1199 	}
1200 
1201 	ts->vccio = devm_regulator_get(&client->dev, "vccio");
1202 	if (IS_ERR(ts->vccio)) {
1203 		error = PTR_ERR(ts->vccio);
1204 		if (error != -EPROBE_DEFER)
1205 			dev_err(&client->dev,
1206 				"Failed to get 'vccio' regulator: %d\n",
1207 				error);
1208 		return error;
1209 	}
1210 
1211 	ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
1212 	if (IS_ERR(ts->reset_gpio)) {
1213 		error = PTR_ERR(ts->reset_gpio);
1214 
1215 		if (error == -EPROBE_DEFER)
1216 			return error;
1217 
1218 		if (error != -ENOENT && error != -ENOSYS) {
1219 			dev_err(&client->dev,
1220 				"failed to get reset gpio: %d\n",
1221 				error);
1222 			return error;
1223 		}
1224 
1225 		ts->keep_power_in_suspend = true;
1226 	}
1227 
1228 	error = elants_i2c_power_on(ts);
1229 	if (error)
1230 		return error;
1231 
1232 	error = devm_add_action(&client->dev, elants_i2c_power_off, ts);
1233 	if (error) {
1234 		dev_err(&client->dev,
1235 			"failed to install power off action: %d\n", error);
1236 		elants_i2c_power_off(ts);
1237 		return error;
1238 	}
1239 
1240 	/* Make sure there is something at this address */
1241 	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1242 			   I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1243 		dev_err(&client->dev, "nothing at this address\n");
1244 		return -ENXIO;
1245 	}
1246 
1247 	error = elants_i2c_initialize(ts);
1248 	if (error) {
1249 		dev_err(&client->dev, "failed to initialize: %d\n", error);
1250 		return error;
1251 	}
1252 
1253 	ts->input = devm_input_allocate_device(&client->dev);
1254 	if (!ts->input) {
1255 		dev_err(&client->dev, "Failed to allocate input device\n");
1256 		return -ENOMEM;
1257 	}
1258 
1259 	ts->input->name = "Elan Touchscreen";
1260 	ts->input->id.bustype = BUS_I2C;
1261 
1262 	__set_bit(BTN_TOUCH, ts->input->keybit);
1263 	__set_bit(EV_ABS, ts->input->evbit);
1264 	__set_bit(EV_KEY, ts->input->evbit);
1265 
1266 	/* Single touch input params setup */
1267 	input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1268 	input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1269 	input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1270 	input_abs_set_res(ts->input, ABS_X, ts->x_res);
1271 	input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1272 
1273 	/* Multitouch input params setup */
1274 	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1275 				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1276 	if (error) {
1277 		dev_err(&client->dev,
1278 			"failed to initialize MT slots: %d\n", error);
1279 		return error;
1280 	}
1281 
1282 	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1283 	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1284 	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1285 	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1286 	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1287 	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1288 
1289 	error = input_register_device(ts->input);
1290 	if (error) {
1291 		dev_err(&client->dev,
1292 			"unable to register input device: %d\n", error);
1293 		return error;
1294 	}
1295 
1296 	/*
1297 	 * Platform code (ACPI, DTS) should normally set up interrupt
1298 	 * for us, but in case it did not let's fall back to using falling
1299 	 * edge to be compatible with older Chromebooks.
1300 	 */
1301 	irqflags = irq_get_trigger_type(client->irq);
1302 	if (!irqflags)
1303 		irqflags = IRQF_TRIGGER_FALLING;
1304 
1305 	error = devm_request_threaded_irq(&client->dev, client->irq,
1306 					  NULL, elants_i2c_irq,
1307 					  irqflags | IRQF_ONESHOT,
1308 					  client->name, ts);
1309 	if (error) {
1310 		dev_err(&client->dev, "Failed to register interrupt\n");
1311 		return error;
1312 	}
1313 
1314 	/*
1315 	 * Systems using device tree should set up wakeup via DTS,
1316 	 * the rest will configure device as wakeup source by default.
1317 	 */
1318 	if (!client->dev.of_node)
1319 		device_init_wakeup(&client->dev, true);
1320 
1321 	error = devm_device_add_group(&client->dev, &elants_attribute_group);
1322 	if (error) {
1323 		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1324 			error);
1325 		return error;
1326 	}
1327 
1328 	return 0;
1329 }
1330 
elants_i2c_suspend(struct device * dev)1331 static int __maybe_unused elants_i2c_suspend(struct device *dev)
1332 {
1333 	struct i2c_client *client = to_i2c_client(dev);
1334 	struct elants_data *ts = i2c_get_clientdata(client);
1335 	const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1336 	int retry_cnt;
1337 	int error;
1338 
1339 	/* Command not support in IAP recovery mode */
1340 	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1341 		return -EBUSY;
1342 
1343 	disable_irq(client->irq);
1344 
1345 	if (device_may_wakeup(dev)) {
1346 		/*
1347 		 * The device will automatically enter idle mode
1348 		 * that has reduced power consumption.
1349 		 */
1350 		ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1351 	} else if (ts->keep_power_in_suspend) {
1352 		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1353 			error = elants_i2c_send(client, set_sleep_cmd,
1354 						sizeof(set_sleep_cmd));
1355 			if (!error)
1356 				break;
1357 
1358 			dev_err(&client->dev,
1359 				"suspend command failed: %d\n", error);
1360 		}
1361 	} else {
1362 		elants_i2c_power_off(ts);
1363 	}
1364 
1365 	return 0;
1366 }
1367 
elants_i2c_resume(struct device * dev)1368 static int __maybe_unused elants_i2c_resume(struct device *dev)
1369 {
1370 	struct i2c_client *client = to_i2c_client(dev);
1371 	struct elants_data *ts = i2c_get_clientdata(client);
1372 	const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1373 	int retry_cnt;
1374 	int error;
1375 
1376 	if (device_may_wakeup(dev)) {
1377 		if (ts->wake_irq_enabled)
1378 			disable_irq_wake(client->irq);
1379 		elants_i2c_sw_reset(client);
1380 	} else if (ts->keep_power_in_suspend) {
1381 		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1382 			error = elants_i2c_send(client, set_active_cmd,
1383 						sizeof(set_active_cmd));
1384 			if (!error)
1385 				break;
1386 
1387 			dev_err(&client->dev,
1388 				"resume command failed: %d\n", error);
1389 		}
1390 	} else {
1391 		elants_i2c_power_on(ts);
1392 		elants_i2c_initialize(ts);
1393 	}
1394 
1395 	ts->state = ELAN_STATE_NORMAL;
1396 	enable_irq(client->irq);
1397 
1398 	return 0;
1399 }
1400 
1401 static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1402 			 elants_i2c_suspend, elants_i2c_resume);
1403 
1404 static const struct i2c_device_id elants_i2c_id[] = {
1405 	{ DEVICE_NAME, 0 },
1406 	{ }
1407 };
1408 MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1409 
1410 #ifdef CONFIG_ACPI
1411 static const struct acpi_device_id elants_acpi_id[] = {
1412 	{ "ELAN0001", 0 },
1413 	{ }
1414 };
1415 MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1416 #endif
1417 
1418 #ifdef CONFIG_OF
1419 static const struct of_device_id elants_of_match[] = {
1420 	{ .compatible = "elan,ekth3500" },
1421 	{ /* sentinel */ }
1422 };
1423 MODULE_DEVICE_TABLE(of, elants_of_match);
1424 #endif
1425 
1426 static struct i2c_driver elants_i2c_driver = {
1427 	.probe = elants_i2c_probe,
1428 	.id_table = elants_i2c_id,
1429 	.driver = {
1430 		.name = DEVICE_NAME,
1431 		.pm = &elants_i2c_pm_ops,
1432 		.acpi_match_table = ACPI_PTR(elants_acpi_id),
1433 		.of_match_table = of_match_ptr(elants_of_match),
1434 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1435 	},
1436 };
1437 module_i2c_driver(elants_i2c_driver);
1438 
1439 MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1440 MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1441 MODULE_LICENSE("GPL");
1442