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, u8 *version)
263 {
264 	int error;
265 	u8 val[3];
266 
267 	error = elan_i2c_read_cmd(client, ETP_I2C_SM_VERSION_CMD, val);
268 	if (error) {
269 		dev_err(&client->dev, "failed to get SM version: %d\n", error);
270 		return error;
271 	}
272 
273 	*version = val[0];
274 	return 0;
275 }
276 
277 static int elan_i2c_get_product_id(struct i2c_client *client, u8 *id)
278 {
279 	int error;
280 	u8 val[3];
281 
282 	error = elan_i2c_read_cmd(client, ETP_I2C_UNIQUEID_CMD, val);
283 	if (error) {
284 		dev_err(&client->dev, "failed to get product ID: %d\n", error);
285 		return error;
286 	}
287 
288 	*id = val[0];
289 	return 0;
290 }
291 
292 static int elan_i2c_get_checksum(struct i2c_client *client,
293 				 bool iap, u16 *csum)
294 {
295 	int error;
296 	u8 val[3];
297 
298 	error = elan_i2c_read_cmd(client,
299 				  iap ? ETP_I2C_IAP_CHECKSUM_CMD :
300 					ETP_I2C_FW_CHECKSUM_CMD,
301 				  val);
302 	if (error) {
303 		dev_err(&client->dev, "failed to get %s checksum: %d\n",
304 			iap ? "IAP" : "FW", error);
305 		return error;
306 	}
307 
308 	*csum = le16_to_cpup((__le16 *)val);
309 	return 0;
310 }
311 
312 static int elan_i2c_get_max(struct i2c_client *client,
313 			    unsigned int *max_x, unsigned int *max_y)
314 {
315 	int error;
316 	u8 val[3];
317 
318 	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_X_AXIS_CMD, val);
319 	if (error) {
320 		dev_err(&client->dev, "failed to get X dimension: %d\n", error);
321 		return error;
322 	}
323 
324 	*max_x = le16_to_cpup((__le16 *)val) & 0x0fff;
325 
326 	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_Y_AXIS_CMD, val);
327 	if (error) {
328 		dev_err(&client->dev, "failed to get Y dimension: %d\n", error);
329 		return error;
330 	}
331 
332 	*max_y = le16_to_cpup((__le16 *)val) & 0x0fff;
333 
334 	return 0;
335 }
336 
337 static int elan_i2c_get_resolution(struct i2c_client *client,
338 				   u8 *hw_res_x, u8 *hw_res_y)
339 {
340 	int error;
341 	u8 val[3];
342 
343 	error = elan_i2c_read_cmd(client, ETP_I2C_RESOLUTION_CMD, val);
344 	if (error) {
345 		dev_err(&client->dev, "failed to get resolution: %d\n", error);
346 		return error;
347 	}
348 
349 	*hw_res_x = val[0];
350 	*hw_res_y = val[1];
351 
352 	return 0;
353 }
354 
355 static int elan_i2c_get_num_traces(struct i2c_client *client,
356 				   unsigned int *x_traces,
357 				   unsigned int *y_traces)
358 {
359 	int error;
360 	u8 val[3];
361 
362 	error = elan_i2c_read_cmd(client, ETP_I2C_XY_TRACENUM_CMD, val);
363 	if (error) {
364 		dev_err(&client->dev, "failed to get trace info: %d\n", error);
365 		return error;
366 	}
367 
368 	*x_traces = val[0];
369 	*y_traces = val[1];
370 
371 	return 0;
372 }
373 
374 static int elan_i2c_get_pressure_adjustment(struct i2c_client *client,
375 					    int *adjustment)
376 {
377 	int error;
378 	u8 val[3];
379 
380 	error = elan_i2c_read_cmd(client, ETP_I2C_PRESSURE_CMD, val);
381 	if (error) {
382 		dev_err(&client->dev, "failed to get pressure format: %d\n",
383 			error);
384 		return error;
385 	}
386 
387 	if ((val[0] >> 4) & 0x1)
388 		*adjustment = 0;
389 	else
390 		*adjustment = ETP_PRESSURE_OFFSET;
391 
392 	return 0;
393 }
394 
395 static int elan_i2c_iap_get_mode(struct i2c_client *client, enum tp_mode *mode)
396 {
397 	int error;
398 	u16 constant;
399 	u8 val[3];
400 
401 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
402 	if (error) {
403 		dev_err(&client->dev,
404 			"failed to read iap control register: %d\n",
405 			error);
406 		return error;
407 	}
408 
409 	constant = le16_to_cpup((__le16 *)val);
410 	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
411 
412 	*mode = (constant & ETP_I2C_MAIN_MODE_ON) ? MAIN_MODE : IAP_MODE;
413 
414 	return 0;
415 }
416 
417 static int elan_i2c_iap_reset(struct i2c_client *client)
418 {
419 	int error;
420 
421 	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_RESET_CMD,
422 				   ETP_I2C_IAP_RESET);
423 	if (error) {
424 		dev_err(&client->dev, "cannot reset IC: %d\n", error);
425 		return error;
426 	}
427 
428 	return 0;
429 }
430 
431 static int elan_i2c_set_flash_key(struct i2c_client *client)
432 {
433 	int error;
434 
435 	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_CMD,
436 				   ETP_I2C_IAP_PASSWORD);
437 	if (error) {
438 		dev_err(&client->dev, "cannot set flash key: %d\n", error);
439 		return error;
440 	}
441 
442 	return 0;
443 }
444 
445 static int elan_i2c_prepare_fw_update(struct i2c_client *client)
446 {
447 	struct device *dev = &client->dev;
448 	int error;
449 	enum tp_mode mode;
450 	u8 val[3];
451 	u16 password;
452 
453 	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
454 	error = elan_i2c_iap_get_mode(client, &mode);
455 	if (error)
456 		return error;
457 
458 	if (mode == IAP_MODE) {
459 		/* Reset IC */
460 		error = elan_i2c_iap_reset(client);
461 		if (error)
462 			return error;
463 
464 		msleep(30);
465 	}
466 
467 	/* Set flash key*/
468 	error = elan_i2c_set_flash_key(client);
469 	if (error)
470 		return error;
471 
472 	/* Wait for F/W IAP initialization */
473 	msleep(mode == MAIN_MODE ? 100 : 30);
474 
475 	/* Check if we are in IAP mode or not */
476 	error = elan_i2c_iap_get_mode(client, &mode);
477 	if (error)
478 		return error;
479 
480 	if (mode == MAIN_MODE) {
481 		dev_err(dev, "wrong mode: %d\n", mode);
482 		return -EIO;
483 	}
484 
485 	/* Set flash key again */
486 	error = elan_i2c_set_flash_key(client);
487 	if (error)
488 		return error;
489 
490 	/* Wait for F/W IAP initialization */
491 	msleep(30);
492 
493 	/* read back to check we actually enabled successfully. */
494 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CMD, val);
495 	if (error) {
496 		dev_err(dev, "cannot read iap password: %d\n",
497 			error);
498 		return error;
499 	}
500 
501 	password = le16_to_cpup((__le16 *)val);
502 	if (password != ETP_I2C_IAP_PASSWORD) {
503 		dev_err(dev, "wrong iap password: 0x%X\n", password);
504 		return -EIO;
505 	}
506 
507 	return 0;
508 }
509 
510 static int elan_i2c_write_fw_block(struct i2c_client *client,
511 				   const u8 *page, u16 checksum, int idx)
512 {
513 	struct device *dev = &client->dev;
514 	u8 page_store[ETP_FW_PAGE_SIZE + 4];
515 	u8 val[3];
516 	u16 result;
517 	int ret, error;
518 
519 	page_store[0] = ETP_I2C_IAP_REG_L;
520 	page_store[1] = ETP_I2C_IAP_REG_H;
521 	memcpy(&page_store[2], page, ETP_FW_PAGE_SIZE);
522 	/* recode checksum at last two bytes */
523 	put_unaligned_le16(checksum, &page_store[ETP_FW_PAGE_SIZE + 2]);
524 
525 	ret = i2c_master_send(client, page_store, sizeof(page_store));
526 	if (ret != sizeof(page_store)) {
527 		error = ret < 0 ? ret : -EIO;
528 		dev_err(dev, "Failed to write page %d: %d\n", idx, error);
529 		return error;
530 	}
531 
532 	/* Wait for F/W to update one page ROM data. */
533 	msleep(20);
534 
535 	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
536 	if (error) {
537 		dev_err(dev, "Failed to read IAP write result: %d\n", error);
538 		return error;
539 	}
540 
541 	result = le16_to_cpup((__le16 *)val);
542 	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
543 		dev_err(dev, "IAP reports failed write: %04hx\n",
544 			result);
545 		return -EIO;
546 	}
547 
548 	return 0;
549 }
550 
551 static int elan_i2c_finish_fw_update(struct i2c_client *client,
552 				     struct completion *completion)
553 {
554 	struct device *dev = &client->dev;
555 	long ret;
556 	int error;
557 	int len;
558 	u8 buffer[ETP_I2C_INF_LENGTH];
559 
560 	reinit_completion(completion);
561 	enable_irq(client->irq);
562 
563 	error = elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD, ETP_I2C_RESET);
564 	if (!error)
565 		ret = wait_for_completion_interruptible_timeout(completion,
566 							msecs_to_jiffies(300));
567 	disable_irq(client->irq);
568 
569 	if (error) {
570 		dev_err(dev, "device reset failed: %d\n", error);
571 		return error;
572 	} else if (ret == 0) {
573 		dev_err(dev, "timeout waiting for device reset\n");
574 		return -ETIMEDOUT;
575 	} else if (ret < 0) {
576 		error = ret;
577 		dev_err(dev, "error waiting for device reset: %d\n", error);
578 		return error;
579 	}
580 
581 	len = i2c_master_recv(client, buffer, ETP_I2C_INF_LENGTH);
582 	if (len != ETP_I2C_INF_LENGTH) {
583 		error = len < 0 ? len : -EIO;
584 		dev_err(dev, "failed to read INT signal: %d (%d)\n",
585 			error, len);
586 		return error;
587 	}
588 
589 	return 0;
590 }
591 
592 static int elan_i2c_get_report(struct i2c_client *client, u8 *report)
593 {
594 	int len;
595 
596 	len = i2c_master_recv(client, report, ETP_I2C_REPORT_LEN);
597 	if (len < 0) {
598 		dev_err(&client->dev, "failed to read report data: %d\n", len);
599 		return len;
600 	}
601 
602 	if (len != ETP_I2C_REPORT_LEN) {
603 		dev_err(&client->dev,
604 			"wrong report length (%d vs %d expected)\n",
605 			len, ETP_I2C_REPORT_LEN);
606 		return -EIO;
607 	}
608 
609 	return 0;
610 }
611 
612 const struct elan_transport_ops elan_i2c_ops = {
613 	.initialize		= elan_i2c_initialize,
614 	.sleep_control		= elan_i2c_sleep_control,
615 	.power_control		= elan_i2c_power_control,
616 	.set_mode		= elan_i2c_set_mode,
617 
618 	.calibrate		= elan_i2c_calibrate,
619 	.calibrate_result	= elan_i2c_calibrate_result,
620 
621 	.get_baseline_data	= elan_i2c_get_baseline_data,
622 
623 	.get_version		= elan_i2c_get_version,
624 	.get_sm_version		= elan_i2c_get_sm_version,
625 	.get_product_id		= elan_i2c_get_product_id,
626 	.get_checksum		= elan_i2c_get_checksum,
627 	.get_pressure_adjustment = elan_i2c_get_pressure_adjustment,
628 
629 	.get_max		= elan_i2c_get_max,
630 	.get_resolution		= elan_i2c_get_resolution,
631 	.get_num_traces		= elan_i2c_get_num_traces,
632 
633 	.iap_get_mode		= elan_i2c_iap_get_mode,
634 	.iap_reset		= elan_i2c_iap_reset,
635 
636 	.prepare_fw_update	= elan_i2c_prepare_fw_update,
637 	.write_fw_block		= elan_i2c_write_fw_block,
638 	.finish_fw_update	= elan_i2c_finish_fw_update,
639 
640 	.get_report		= elan_i2c_get_report,
641 };
642