1 /*
2  * Elan I2C/SMBus Touchpad driver - I2C interface
3  *
4  * Copyright (c) 2013 ELAN Microelectronics Corp.
5  *
6  * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
7  *
8  * Based on cyapa driver:
9  * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
10  * copyright (c) 2011-2012 Google, Inc.
11  *
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU General Public License version 2 as published
14  * by the Free Software Foundation.
15  *
16  * Trademarks are the property of their respective owners.
17  */
18 
19 #include <linux/completion.h>
20 #include <linux/delay.h>
21 #include <linux/i2c.h>
22 #include <linux/interrupt.h>
23 #include <linux/jiffies.h>
24 #include <linux/kernel.h>
25 #include <linux/sched.h>
26 #include <asm/unaligned.h>
27 
28 #include "elan_i2c.h"
29 
30 /* Elan i2c commands */
31 #define ETP_I2C_RESET			0x0100
32 #define ETP_I2C_WAKE_UP			0x0800
33 #define ETP_I2C_SLEEP			0x0801
34 #define ETP_I2C_DESC_CMD		0x0001
35 #define ETP_I2C_REPORT_DESC_CMD		0x0002
36 #define ETP_I2C_STAND_CMD		0x0005
37 #define ETP_I2C_UNIQUEID_CMD		0x0101
38 #define ETP_I2C_FW_VERSION_CMD		0x0102
39 #define ETP_I2C_SM_VERSION_CMD		0x0103
40 #define ETP_I2C_XY_TRACENUM_CMD		0x0105
41 #define ETP_I2C_MAX_X_AXIS_CMD		0x0106
42 #define ETP_I2C_MAX_Y_AXIS_CMD		0x0107
43 #define ETP_I2C_RESOLUTION_CMD		0x0108
44 #define ETP_I2C_PRESSURE_CMD		0x010A
45 #define ETP_I2C_IAP_VERSION_CMD		0x0110
46 #define ETP_I2C_SET_CMD			0x0300
47 #define ETP_I2C_POWER_CMD		0x0307
48 #define ETP_I2C_FW_CHECKSUM_CMD		0x030F
49 #define ETP_I2C_IAP_CTRL_CMD		0x0310
50 #define ETP_I2C_IAP_CMD			0x0311
51 #define ETP_I2C_IAP_RESET_CMD		0x0314
52 #define ETP_I2C_IAP_CHECKSUM_CMD	0x0315
53 #define ETP_I2C_CALIBRATE_CMD		0x0316
54 #define ETP_I2C_MAX_BASELINE_CMD	0x0317
55 #define ETP_I2C_MIN_BASELINE_CMD	0x0318
56 
57 #define ETP_I2C_REPORT_LEN		34
58 #define ETP_I2C_DESC_LENGTH		30
59 #define ETP_I2C_REPORT_DESC_LENGTH	158
60 #define ETP_I2C_INF_LENGTH		2
61 #define ETP_I2C_IAP_PASSWORD		0x1EA5
62 #define ETP_I2C_IAP_RESET		0xF0F0
63 #define ETP_I2C_MAIN_MODE_ON		(1 << 9)
64 #define ETP_I2C_IAP_REG_L		0x01
65 #define ETP_I2C_IAP_REG_H		0x06
66 
67 static int elan_i2c_read_block(struct i2c_client *client,
68 			       u16 reg, u8 *val, u16 len)
69 {
70 	__le16 buf[] = {
71 		cpu_to_le16(reg),
72 	};
73 	struct i2c_msg msgs[] = {
74 		{
75 			.addr = client->addr,
76 			.flags = client->flags & I2C_M_TEN,
77 			.len = sizeof(buf),
78 			.buf = (u8 *)buf,
79 		},
80 		{
81 			.addr = client->addr,
82 			.flags = (client->flags & I2C_M_TEN) | I2C_M_RD,
83 			.len = len,
84 			.buf = val,
85 		}
86 	};
87 	int ret;
88 
89 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
90 	return ret == ARRAY_SIZE(msgs) ? 0 : (ret < 0 ? ret : -EIO);
91 }
92 
93 static int elan_i2c_read_cmd(struct i2c_client *client, u16 reg, u8 *val)
94 {
95 	int retval;
96 
97 	retval = elan_i2c_read_block(client, reg, val, ETP_I2C_INF_LENGTH);
98 	if (retval < 0) {
99 		dev_err(&client->dev, "reading cmd (0x%04x) fail.\n", reg);
100 		return retval;
101 	}
102 
103 	return 0;
104 }
105 
106 static int elan_i2c_write_cmd(struct i2c_client *client, u16 reg, u16 cmd)
107 {
108 	__le16 buf[] = {
109 		cpu_to_le16(reg),
110 		cpu_to_le16(cmd),
111 	};
112 	struct i2c_msg msg = {
113 		.addr = client->addr,
114 		.flags = client->flags & I2C_M_TEN,
115 		.len = sizeof(buf),
116 		.buf = (u8 *)buf,
117 	};
118 	int ret;
119 
120 	ret = i2c_transfer(client->adapter, &msg, 1);
121 	if (ret != 1) {
122 		if (ret >= 0)
123 			ret = -EIO;
124 		dev_err(&client->dev, "writing cmd (0x%04x) failed: %d\n",
125 			reg, ret);
126 		return ret;
127 	}
128 
129 	return 0;
130 }
131 
132 static int elan_i2c_initialize(struct i2c_client *client)
133 {
134 	struct device *dev = &client->dev;
135 	int error;
136 	u8 val[256];
137 
138 	error = elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD, ETP_I2C_RESET);
139 	if (error) {
140 		dev_err(dev, "device reset failed: %d\n", error);
141 		return error;
142 	}
143 
144 	/* Wait for the device to reset */
145 	msleep(100);
146 
147 	/* get reset acknowledgement 0000 */
148 	error = i2c_master_recv(client, val, ETP_I2C_INF_LENGTH);
149 	if (error < 0) {
150 		dev_err(dev, "failed to read reset response: %d\n", error);
151 		return error;
152 	}
153 
154 	error = elan_i2c_read_block(client, ETP_I2C_DESC_CMD,
155 				    val, ETP_I2C_DESC_LENGTH);
156 	if (error) {
157 		dev_err(dev, "cannot get device descriptor: %d\n", error);
158 		return error;
159 	}
160 
161 	error = elan_i2c_read_block(client, ETP_I2C_REPORT_DESC_CMD,
162 				    val, ETP_I2C_REPORT_DESC_LENGTH);
163 	if (error) {
164 		dev_err(dev, "fetching report descriptor failed.: %d\n", error);
165 		return error;
166 	}
167 
168 	return 0;
169 }
170 
171 static int elan_i2c_sleep_control(struct i2c_client *client, bool sleep)
172 {
173 	return elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD,
174 				  sleep ? ETP_I2C_SLEEP : ETP_I2C_WAKE_UP);
175 }
176 
177 static int elan_i2c_power_control(struct i2c_client *client, bool enable)
178 {
179 	u8 val[2];
180 	u16 reg;
181 	int error;
182 
183 	error = elan_i2c_read_cmd(client, ETP_I2C_POWER_CMD, val);
184 	if (error) {
185 		dev_err(&client->dev,
186 			"failed to read current power state: %d\n",
187 			error);
188 		return error;
189 	}
190 
191 	reg = le16_to_cpup((__le16 *)val);
192 	if (enable)
193 		reg &= ~ETP_DISABLE_POWER;
194 	else
195 		reg |= ETP_DISABLE_POWER;
196 
197 	error = elan_i2c_write_cmd(client, ETP_I2C_POWER_CMD, reg);
198 	if (error) {
199 		dev_err(&client->dev,
200 			"failed to write current power state: %d\n",
201 			error);
202 		return error;
203 	}
204 
205 	return 0;
206 }
207 
208 static int elan_i2c_set_mode(struct i2c_client *client, u8 mode)
209 {
210 	return elan_i2c_write_cmd(client, ETP_I2C_SET_CMD, mode);
211 }
212 
213 
214 static int elan_i2c_calibrate(struct i2c_client *client)
215 {
216 	return elan_i2c_write_cmd(client, ETP_I2C_CALIBRATE_CMD, 1);
217 }
218 
219 static int elan_i2c_calibrate_result(struct i2c_client *client, u8 *val)
220 {
221 	return elan_i2c_read_block(client, ETP_I2C_CALIBRATE_CMD, val, 1);
222 }
223 
224 static int elan_i2c_get_baseline_data(struct i2c_client *client,
225 				      bool max_baseline, u8 *value)
226 {
227 	int error;
228 	u8 val[3];
229 
230 	error = elan_i2c_read_cmd(client,
231 				  max_baseline ? ETP_I2C_MAX_BASELINE_CMD :
232 						 ETP_I2C_MIN_BASELINE_CMD,
233 				  val);
234 	if (error)
235 		return error;
236 
237 	*value = le16_to_cpup((__le16 *)val);
238 
239 	return 0;
240 }
241 
242 static int elan_i2c_get_version(struct i2c_client *client,
243 				bool iap, u8 *version)
244 {
245 	int error;
246 	u8 val[3];
247 
248 	error = elan_i2c_read_cmd(client,
249 				  iap ? ETP_I2C_IAP_VERSION_CMD :
250 					ETP_I2C_FW_VERSION_CMD,
251 				  val);
252 	if (error) {
253 		dev_err(&client->dev, "failed to get %s version: %d\n",
254 			iap ? "IAP" : "FW", error);
255 		return error;
256 	}
257 
258 	*version = val[0];
259 	return 0;
260 }
261 
262 static int elan_i2c_get_sm_version(struct i2c_client *client,
263 				   u8 *ic_type, u8 *version)
264 {
265 	int error;
266 	u8 val[3];
267 
268 	error = elan_i2c_read_cmd(client, ETP_I2C_SM_VERSION_CMD, val);
269 	if (error) {
270 		dev_err(&client->dev, "failed to get SM version: %d\n", error);
271 		return error;
272 	}
273 
274 	*version = val[0];
275 	*ic_type = val[1];
276 	return 0;
277 }
278 
279 static int elan_i2c_get_product_id(struct i2c_client *client, u16 *id)
280 {
281 	int error;
282 	u8 val[3];
283 
284 	error = elan_i2c_read_cmd(client, ETP_I2C_UNIQUEID_CMD, val);
285 	if (error) {
286 		dev_err(&client->dev, "failed to get product ID: %d\n", error);
287 		return error;
288 	}
289 
290 	*id = le16_to_cpup((__le16 *)val);
291 	return 0;
292 }
293 
294 static int elan_i2c_get_checksum(struct i2c_client *client,
295 				 bool iap, u16 *csum)
296 {
297 	int error;
298 	u8 val[3];
299 
300 	error = elan_i2c_read_cmd(client,
301 				  iap ? ETP_I2C_IAP_CHECKSUM_CMD :
302 					ETP_I2C_FW_CHECKSUM_CMD,
303 				  val);
304 	if (error) {
305 		dev_err(&client->dev, "failed to get %s checksum: %d\n",
306 			iap ? "IAP" : "FW", error);
307 		return error;
308 	}
309 
310 	*csum = le16_to_cpup((__le16 *)val);
311 	return 0;
312 }
313 
314 static int elan_i2c_get_max(struct i2c_client *client,
315 			    unsigned int *max_x, unsigned int *max_y)
316 {
317 	int error;
318 	u8 val[3];
319 
320 	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_X_AXIS_CMD, val);
321 	if (error) {
322 		dev_err(&client->dev, "failed to get X dimension: %d\n", error);
323 		return error;
324 	}
325 
326 	*max_x = le16_to_cpup((__le16 *)val) & 0x0fff;
327 
328 	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_Y_AXIS_CMD, val);
329 	if (error) {
330 		dev_err(&client->dev, "failed to get Y dimension: %d\n", error);
331 		return error;
332 	}
333 
334 	*max_y = le16_to_cpup((__le16 *)val) & 0x0fff;
335 
336 	return 0;
337 }
338 
339 static int elan_i2c_get_resolution(struct i2c_client *client,
340 				   u8 *hw_res_x, u8 *hw_res_y)
341 {
342 	int error;
343 	u8 val[3];
344 
345 	error = elan_i2c_read_cmd(client, ETP_I2C_RESOLUTION_CMD, val);
346 	if (error) {
347 		dev_err(&client->dev, "failed to get resolution: %d\n", error);
348 		return error;
349 	}
350 
351 	*hw_res_x = val[0];
352 	*hw_res_y = val[1];
353 
354 	return 0;
355 }
356 
357 static int elan_i2c_get_num_traces(struct i2c_client *client,
358 				   unsigned int *x_traces,
359 				   unsigned int *y_traces)
360 {
361 	int error;
362 	u8 val[3];
363 
364 	error = elan_i2c_read_cmd(client, ETP_I2C_XY_TRACENUM_CMD, val);
365 	if (error) {
366 		dev_err(&client->dev, "failed to get trace info: %d\n", error);
367 		return error;
368 	}
369 
370 	*x_traces = val[0];
371 	*y_traces = val[1];
372 
373 	return 0;
374 }
375 
376 static int elan_i2c_get_pressure_adjustment(struct i2c_client *client,
377 					    int *adjustment)
378 {
379 	int error;
380 	u8 val[3];
381 
382 	error = elan_i2c_read_cmd(client, ETP_I2C_PRESSURE_CMD, val);
383 	if (error) {
384 		dev_err(&client->dev, "failed to get pressure format: %d\n",
385 			error);
386 		return error;
387 	}
388 
389 	if ((val[0] >> 4) & 0x1)
390 		*adjustment = 0;
391 	else
392 		*adjustment = ETP_PRESSURE_OFFSET;
393 
394 	return 0;
395 }
396 
397 static int elan_i2c_iap_get_mode(struct i2c_client *client, enum tp_mode *mode)
398 {
399 	int error;
400 	u16 constant;
401 	u8 val[3];
402 
403 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
404 	if (error) {
405 		dev_err(&client->dev,
406 			"failed to read iap control register: %d\n",
407 			error);
408 		return error;
409 	}
410 
411 	constant = le16_to_cpup((__le16 *)val);
412 	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
413 
414 	*mode = (constant & ETP_I2C_MAIN_MODE_ON) ? MAIN_MODE : IAP_MODE;
415 
416 	return 0;
417 }
418 
419 static int elan_i2c_iap_reset(struct i2c_client *client)
420 {
421 	int error;
422 
423 	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_RESET_CMD,
424 				   ETP_I2C_IAP_RESET);
425 	if (error) {
426 		dev_err(&client->dev, "cannot reset IC: %d\n", error);
427 		return error;
428 	}
429 
430 	return 0;
431 }
432 
433 static int elan_i2c_set_flash_key(struct i2c_client *client)
434 {
435 	int error;
436 
437 	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_CMD,
438 				   ETP_I2C_IAP_PASSWORD);
439 	if (error) {
440 		dev_err(&client->dev, "cannot set flash key: %d\n", error);
441 		return error;
442 	}
443 
444 	return 0;
445 }
446 
447 static int elan_i2c_prepare_fw_update(struct i2c_client *client)
448 {
449 	struct device *dev = &client->dev;
450 	int error;
451 	enum tp_mode mode;
452 	u8 val[3];
453 	u16 password;
454 
455 	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
456 	error = elan_i2c_iap_get_mode(client, &mode);
457 	if (error)
458 		return error;
459 
460 	if (mode == IAP_MODE) {
461 		/* Reset IC */
462 		error = elan_i2c_iap_reset(client);
463 		if (error)
464 			return error;
465 
466 		msleep(30);
467 	}
468 
469 	/* Set flash key*/
470 	error = elan_i2c_set_flash_key(client);
471 	if (error)
472 		return error;
473 
474 	/* Wait for F/W IAP initialization */
475 	msleep(mode == MAIN_MODE ? 100 : 30);
476 
477 	/* Check if we are in IAP mode or not */
478 	error = elan_i2c_iap_get_mode(client, &mode);
479 	if (error)
480 		return error;
481 
482 	if (mode == MAIN_MODE) {
483 		dev_err(dev, "wrong mode: %d\n", mode);
484 		return -EIO;
485 	}
486 
487 	/* Set flash key again */
488 	error = elan_i2c_set_flash_key(client);
489 	if (error)
490 		return error;
491 
492 	/* Wait for F/W IAP initialization */
493 	msleep(30);
494 
495 	/* read back to check we actually enabled successfully. */
496 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CMD, val);
497 	if (error) {
498 		dev_err(dev, "cannot read iap password: %d\n",
499 			error);
500 		return error;
501 	}
502 
503 	password = le16_to_cpup((__le16 *)val);
504 	if (password != ETP_I2C_IAP_PASSWORD) {
505 		dev_err(dev, "wrong iap password: 0x%X\n", password);
506 		return -EIO;
507 	}
508 
509 	return 0;
510 }
511 
512 static int elan_i2c_write_fw_block(struct i2c_client *client,
513 				   const u8 *page, u16 checksum, int idx)
514 {
515 	struct device *dev = &client->dev;
516 	u8 page_store[ETP_FW_PAGE_SIZE + 4];
517 	u8 val[3];
518 	u16 result;
519 	int ret, error;
520 
521 	page_store[0] = ETP_I2C_IAP_REG_L;
522 	page_store[1] = ETP_I2C_IAP_REG_H;
523 	memcpy(&page_store[2], page, ETP_FW_PAGE_SIZE);
524 	/* recode checksum at last two bytes */
525 	put_unaligned_le16(checksum, &page_store[ETP_FW_PAGE_SIZE + 2]);
526 
527 	ret = i2c_master_send(client, page_store, sizeof(page_store));
528 	if (ret != sizeof(page_store)) {
529 		error = ret < 0 ? ret : -EIO;
530 		dev_err(dev, "Failed to write page %d: %d\n", idx, error);
531 		return error;
532 	}
533 
534 	/* Wait for F/W to update one page ROM data. */
535 	msleep(20);
536 
537 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
538 	if (error) {
539 		dev_err(dev, "Failed to read IAP write result: %d\n", error);
540 		return error;
541 	}
542 
543 	result = le16_to_cpup((__le16 *)val);
544 	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
545 		dev_err(dev, "IAP reports failed write: %04hx\n",
546 			result);
547 		return -EIO;
548 	}
549 
550 	return 0;
551 }
552 
553 static int elan_i2c_finish_fw_update(struct i2c_client *client,
554 				     struct completion *completion)
555 {
556 	struct device *dev = &client->dev;
557 	long ret;
558 	int error;
559 	int len;
560 	u8 buffer[ETP_I2C_INF_LENGTH];
561 
562 	reinit_completion(completion);
563 	enable_irq(client->irq);
564 
565 	error = elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD, ETP_I2C_RESET);
566 	if (!error)
567 		ret = wait_for_completion_interruptible_timeout(completion,
568 							msecs_to_jiffies(300));
569 	disable_irq(client->irq);
570 
571 	if (error) {
572 		dev_err(dev, "device reset failed: %d\n", error);
573 		return error;
574 	} else if (ret == 0) {
575 		dev_err(dev, "timeout waiting for device reset\n");
576 		return -ETIMEDOUT;
577 	} else if (ret < 0) {
578 		error = ret;
579 		dev_err(dev, "error waiting for device reset: %d\n", error);
580 		return error;
581 	}
582 
583 	len = i2c_master_recv(client, buffer, ETP_I2C_INF_LENGTH);
584 	if (len != ETP_I2C_INF_LENGTH) {
585 		error = len < 0 ? len : -EIO;
586 		dev_err(dev, "failed to read INT signal: %d (%d)\n",
587 			error, len);
588 		return error;
589 	}
590 
591 	return 0;
592 }
593 
594 static int elan_i2c_get_report(struct i2c_client *client, u8 *report)
595 {
596 	int len;
597 
598 	len = i2c_master_recv(client, report, ETP_I2C_REPORT_LEN);
599 	if (len < 0) {
600 		dev_err(&client->dev, "failed to read report data: %d\n", len);
601 		return len;
602 	}
603 
604 	if (len != ETP_I2C_REPORT_LEN) {
605 		dev_err(&client->dev,
606 			"wrong report length (%d vs %d expected)\n",
607 			len, ETP_I2C_REPORT_LEN);
608 		return -EIO;
609 	}
610 
611 	return 0;
612 }
613 
614 const struct elan_transport_ops elan_i2c_ops = {
615 	.initialize		= elan_i2c_initialize,
616 	.sleep_control		= elan_i2c_sleep_control,
617 	.power_control		= elan_i2c_power_control,
618 	.set_mode		= elan_i2c_set_mode,
619 
620 	.calibrate		= elan_i2c_calibrate,
621 	.calibrate_result	= elan_i2c_calibrate_result,
622 
623 	.get_baseline_data	= elan_i2c_get_baseline_data,
624 
625 	.get_version		= elan_i2c_get_version,
626 	.get_sm_version		= elan_i2c_get_sm_version,
627 	.get_product_id		= elan_i2c_get_product_id,
628 	.get_checksum		= elan_i2c_get_checksum,
629 	.get_pressure_adjustment = elan_i2c_get_pressure_adjustment,
630 
631 	.get_max		= elan_i2c_get_max,
632 	.get_resolution		= elan_i2c_get_resolution,
633 	.get_num_traces		= elan_i2c_get_num_traces,
634 
635 	.iap_get_mode		= elan_i2c_iap_get_mode,
636 	.iap_reset		= elan_i2c_iap_reset,
637 
638 	.prepare_fw_update	= elan_i2c_prepare_fw_update,
639 	.write_fw_block		= elan_i2c_write_fw_block,
640 	.finish_fw_update	= elan_i2c_finish_fw_update,
641 
642 	.get_report		= elan_i2c_get_report,
643 };
644