1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Elan I2C/SMBus Touchpad driver - SMBus interface
4  *
5  * Copyright (c) 2013 ELAN Microelectronics Corp.
6  *
7  * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
8  *
9  * Based on cyapa driver:
10  * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
11  * copyright (c) 2011-2012 Google, Inc.
12  *
13  * Trademarks are the property of their respective owners.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/i2c.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 
21 #include "elan_i2c.h"
22 
23 /* Elan SMbus commands */
24 #define ETP_SMBUS_IAP_CMD		0x00
25 #define ETP_SMBUS_ENABLE_TP		0x20
26 #define ETP_SMBUS_SLEEP_CMD		0x21
27 #define ETP_SMBUS_IAP_PASSWORD_WRITE	0x29
28 #define ETP_SMBUS_IAP_PASSWORD_READ	0x80
29 #define ETP_SMBUS_WRITE_FW_BLOCK	0x2A
30 #define ETP_SMBUS_IAP_RESET_CMD		0x2B
31 #define ETP_SMBUS_RANGE_CMD		0xA0
32 #define ETP_SMBUS_FW_VERSION_CMD	0xA1
33 #define ETP_SMBUS_XY_TRACENUM_CMD	0xA2
34 #define ETP_SMBUS_SM_VERSION_CMD	0xA3
35 #define ETP_SMBUS_UNIQUEID_CMD		0xA3
36 #define ETP_SMBUS_RESOLUTION_CMD	0xA4
37 #define ETP_SMBUS_HELLOPACKET_CMD	0xA7
38 #define ETP_SMBUS_PACKET_QUERY		0xA8
39 #define ETP_SMBUS_IAP_VERSION_CMD	0xAC
40 #define ETP_SMBUS_IAP_CTRL_CMD		0xAD
41 #define ETP_SMBUS_IAP_CHECKSUM_CMD	0xAE
42 #define ETP_SMBUS_FW_CHECKSUM_CMD	0xAF
43 #define ETP_SMBUS_MAX_BASELINE_CMD	0xC3
44 #define ETP_SMBUS_MIN_BASELINE_CMD	0xC4
45 #define ETP_SMBUS_CALIBRATE_QUERY	0xC5
46 
47 #define ETP_SMBUS_REPORT_LEN		32
48 #define ETP_SMBUS_REPORT_OFFSET		2
49 #define ETP_SMBUS_HELLOPACKET_LEN	5
50 #define ETP_SMBUS_IAP_PASSWORD		0x1234
51 #define ETP_SMBUS_IAP_MODE_ON		(1 << 6)
52 
53 static int elan_smbus_initialize(struct i2c_client *client)
54 {
55 	u8 check[ETP_SMBUS_HELLOPACKET_LEN] = { 0x55, 0x55, 0x55, 0x55, 0x55 };
56 	u8 values[I2C_SMBUS_BLOCK_MAX] = {0};
57 	int len, error;
58 
59 	/* Get hello packet */
60 	len = i2c_smbus_read_block_data(client,
61 					ETP_SMBUS_HELLOPACKET_CMD, values);
62 	if (len != ETP_SMBUS_HELLOPACKET_LEN) {
63 		dev_err(&client->dev, "hello packet length fail: %d\n", len);
64 		error = len < 0 ? len : -EIO;
65 		return error;
66 	}
67 
68 	/* compare hello packet */
69 	if (memcmp(values, check, ETP_SMBUS_HELLOPACKET_LEN)) {
70 		dev_err(&client->dev, "hello packet fail [%*ph]\n",
71 			ETP_SMBUS_HELLOPACKET_LEN, values);
72 		return -ENXIO;
73 	}
74 
75 	/* enable tp */
76 	error = i2c_smbus_write_byte(client, ETP_SMBUS_ENABLE_TP);
77 	if (error) {
78 		dev_err(&client->dev, "failed to enable touchpad: %d\n", error);
79 		return error;
80 	}
81 
82 	return 0;
83 }
84 
85 static int elan_smbus_set_mode(struct i2c_client *client, u8 mode)
86 {
87 	u8 cmd[4] = { 0x00, 0x07, 0x00, mode };
88 
89 	return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
90 					  sizeof(cmd), cmd);
91 }
92 
93 static int elan_smbus_sleep_control(struct i2c_client *client, bool sleep)
94 {
95 	if (sleep)
96 		return i2c_smbus_write_byte(client, ETP_SMBUS_SLEEP_CMD);
97 	else
98 		return 0; /* XXX should we send ETP_SMBUS_ENABLE_TP here? */
99 }
100 
101 static int elan_smbus_power_control(struct i2c_client *client, bool enable)
102 {
103 	return 0; /* A no-op */
104 }
105 
106 static int elan_smbus_calibrate(struct i2c_client *client)
107 {
108 	u8 cmd[4] = { 0x00, 0x08, 0x00, 0x01 };
109 
110 	return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
111 					  sizeof(cmd), cmd);
112 }
113 
114 static int elan_smbus_calibrate_result(struct i2c_client *client, u8 *val)
115 {
116 	int error;
117 	u8 buf[I2C_SMBUS_BLOCK_MAX] = {0};
118 
119 	BUILD_BUG_ON(ETP_CALIBRATE_MAX_LEN > sizeof(buf));
120 
121 	error = i2c_smbus_read_block_data(client,
122 					  ETP_SMBUS_CALIBRATE_QUERY, buf);
123 	if (error < 0)
124 		return error;
125 
126 	memcpy(val, buf, ETP_CALIBRATE_MAX_LEN);
127 	return 0;
128 }
129 
130 static int elan_smbus_get_baseline_data(struct i2c_client *client,
131 					bool max_baseline, u8 *value)
132 {
133 	int error;
134 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
135 
136 	error = i2c_smbus_read_block_data(client,
137 					  max_baseline ?
138 						ETP_SMBUS_MAX_BASELINE_CMD :
139 						ETP_SMBUS_MIN_BASELINE_CMD,
140 					  val);
141 	if (error < 0)
142 		return error;
143 
144 	*value = be16_to_cpup((__be16 *)val);
145 
146 	return 0;
147 }
148 
149 static int elan_smbus_get_version(struct i2c_client *client,
150 				  bool iap, u8 *version)
151 {
152 	int error;
153 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
154 
155 	error = i2c_smbus_read_block_data(client,
156 					  iap ? ETP_SMBUS_IAP_VERSION_CMD :
157 						ETP_SMBUS_FW_VERSION_CMD,
158 					  val);
159 	if (error < 0) {
160 		dev_err(&client->dev, "failed to get %s version: %d\n",
161 			iap ? "IAP" : "FW", error);
162 		return error;
163 	}
164 
165 	*version = val[2];
166 	return 0;
167 }
168 
169 static int elan_smbus_get_sm_version(struct i2c_client *client,
170 				     u16 *ic_type, u8 *version,
171 				     u8 *clickpad)
172 {
173 	int error;
174 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
175 
176 	error = i2c_smbus_read_block_data(client,
177 					  ETP_SMBUS_SM_VERSION_CMD, val);
178 	if (error < 0) {
179 		dev_err(&client->dev, "failed to get SM version: %d\n", error);
180 		return error;
181 	}
182 
183 	*version = val[0];
184 	*ic_type = val[1];
185 	*clickpad = val[0] & 0x10;
186 	return 0;
187 }
188 
189 static int elan_smbus_get_product_id(struct i2c_client *client, u16 *id)
190 {
191 	int error;
192 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
193 
194 	error = i2c_smbus_read_block_data(client,
195 					  ETP_SMBUS_UNIQUEID_CMD, val);
196 	if (error < 0) {
197 		dev_err(&client->dev, "failed to get product ID: %d\n", error);
198 		return error;
199 	}
200 
201 	*id = be16_to_cpup((__be16 *)val);
202 	return 0;
203 }
204 
205 static int elan_smbus_get_checksum(struct i2c_client *client,
206 				   bool iap, u16 *csum)
207 {
208 	int error;
209 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
210 
211 	error = i2c_smbus_read_block_data(client,
212 					  iap ? ETP_SMBUS_FW_CHECKSUM_CMD :
213 						ETP_SMBUS_IAP_CHECKSUM_CMD,
214 					  val);
215 	if (error < 0) {
216 		dev_err(&client->dev, "failed to get %s checksum: %d\n",
217 			iap ? "IAP" : "FW", error);
218 		return error;
219 	}
220 
221 	*csum = be16_to_cpup((__be16 *)val);
222 	return 0;
223 }
224 
225 static int elan_smbus_get_max(struct i2c_client *client,
226 			      unsigned int *max_x, unsigned int *max_y)
227 {
228 	int ret;
229 	int error;
230 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
231 
232 	ret = i2c_smbus_read_block_data(client, ETP_SMBUS_RANGE_CMD, val);
233 	if (ret != 3) {
234 		error = ret < 0 ? ret : -EIO;
235 		dev_err(&client->dev, "failed to get dimensions: %d\n", error);
236 		return error;
237 	}
238 
239 	*max_x = (0x0f & val[0]) << 8 | val[1];
240 	*max_y = (0xf0 & val[0]) << 4 | val[2];
241 
242 	return 0;
243 }
244 
245 static int elan_smbus_get_resolution(struct i2c_client *client,
246 				     u8 *hw_res_x, u8 *hw_res_y)
247 {
248 	int ret;
249 	int error;
250 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
251 
252 	ret = i2c_smbus_read_block_data(client, ETP_SMBUS_RESOLUTION_CMD, val);
253 	if (ret != 3) {
254 		error = ret < 0 ? ret : -EIO;
255 		dev_err(&client->dev, "failed to get resolution: %d\n", error);
256 		return error;
257 	}
258 
259 	*hw_res_x = val[1] & 0x0F;
260 	*hw_res_y = (val[1] & 0xF0) >> 4;
261 
262 	return 0;
263 }
264 
265 static int elan_smbus_get_num_traces(struct i2c_client *client,
266 				     unsigned int *x_traces,
267 				     unsigned int *y_traces)
268 {
269 	int ret;
270 	int error;
271 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
272 
273 	ret = i2c_smbus_read_block_data(client, ETP_SMBUS_XY_TRACENUM_CMD, val);
274 	if (ret != 3) {
275 		error = ret < 0 ? ret : -EIO;
276 		dev_err(&client->dev, "failed to get trace info: %d\n", error);
277 		return error;
278 	}
279 
280 	*x_traces = val[1];
281 	*y_traces = val[2];
282 
283 	return 0;
284 }
285 
286 static int elan_smbus_get_pressure_adjustment(struct i2c_client *client,
287 					      int *adjustment)
288 {
289 	*adjustment = ETP_PRESSURE_OFFSET;
290 	return 0;
291 }
292 
293 static int elan_smbus_iap_get_mode(struct i2c_client *client,
294 				   enum tp_mode *mode)
295 {
296 	int error;
297 	u16 constant;
298 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
299 
300 	error = i2c_smbus_read_block_data(client, ETP_SMBUS_IAP_CTRL_CMD, val);
301 	if (error < 0) {
302 		dev_err(&client->dev, "failed to read iap ctrol register: %d\n",
303 			error);
304 		return error;
305 	}
306 
307 	constant = be16_to_cpup((__be16 *)val);
308 	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
309 
310 	*mode = (constant & ETP_SMBUS_IAP_MODE_ON) ? IAP_MODE : MAIN_MODE;
311 
312 	return 0;
313 }
314 
315 static int elan_smbus_iap_reset(struct i2c_client *client)
316 {
317 	int error;
318 
319 	error = i2c_smbus_write_byte(client, ETP_SMBUS_IAP_RESET_CMD);
320 	if (error) {
321 		dev_err(&client->dev, "cannot reset IC: %d\n", error);
322 		return error;
323 	}
324 
325 	return 0;
326 }
327 
328 static int elan_smbus_set_flash_key(struct i2c_client *client)
329 {
330 	int error;
331 	u8 cmd[4] = { 0x00, 0x0B, 0x00, 0x5A };
332 
333 	error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
334 					   sizeof(cmd), cmd);
335 	if (error) {
336 		dev_err(&client->dev, "cannot set flash key: %d\n", error);
337 		return error;
338 	}
339 
340 	return 0;
341 }
342 
343 static int elan_smbus_prepare_fw_update(struct i2c_client *client)
344 {
345 	struct device *dev = &client->dev;
346 	int len;
347 	int error;
348 	enum tp_mode mode;
349 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
350 	u8 cmd[4] = {0x0F, 0x78, 0x00, 0x06};
351 	u16 password;
352 
353 	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
354 	error = elan_smbus_iap_get_mode(client, &mode);
355 	if (error)
356 		return error;
357 
358 	if (mode == MAIN_MODE) {
359 
360 		/* set flash key */
361 		error = elan_smbus_set_flash_key(client);
362 		if (error)
363 			return error;
364 
365 		/* write iap password */
366 		if (i2c_smbus_write_byte(client,
367 					 ETP_SMBUS_IAP_PASSWORD_WRITE) < 0) {
368 			dev_err(dev, "cannot write iap password\n");
369 			return -EIO;
370 		}
371 
372 		error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
373 						   sizeof(cmd), cmd);
374 		if (error) {
375 			dev_err(dev, "failed to write iap password: %d\n",
376 				error);
377 			return error;
378 		}
379 
380 		/*
381 		 * Read back password to make sure we enabled flash
382 		 * successfully.
383 		 */
384 		len = i2c_smbus_read_block_data(client,
385 						ETP_SMBUS_IAP_PASSWORD_READ,
386 						val);
387 		if (len < (int)sizeof(u16)) {
388 			error = len < 0 ? len : -EIO;
389 			dev_err(dev, "failed to read iap password: %d\n",
390 				error);
391 			return error;
392 		}
393 
394 		password = be16_to_cpup((__be16 *)val);
395 		if (password != ETP_SMBUS_IAP_PASSWORD) {
396 			dev_err(dev, "wrong iap password = 0x%X\n", password);
397 			return -EIO;
398 		}
399 
400 		/* Wait 30ms for MAIN_MODE change to IAP_MODE */
401 		msleep(30);
402 	}
403 
404 	error = elan_smbus_set_flash_key(client);
405 	if (error)
406 		return error;
407 
408 	/* Reset IC */
409 	error = elan_smbus_iap_reset(client);
410 	if (error)
411 		return error;
412 
413 	return 0;
414 }
415 
416 
417 static int elan_smbus_write_fw_block(struct i2c_client *client,
418 				     const u8 *page, u16 checksum, int idx)
419 {
420 	struct device *dev = &client->dev;
421 	int error;
422 	u16 result;
423 	u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
424 
425 	/*
426 	 * Due to the limitation of smbus protocol limiting
427 	 * transfer to 32 bytes at a time, we must split block
428 	 * in 2 transfers.
429 	 */
430 	error = i2c_smbus_write_block_data(client,
431 					   ETP_SMBUS_WRITE_FW_BLOCK,
432 					   ETP_FW_PAGE_SIZE / 2,
433 					   page);
434 	if (error) {
435 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
436 			idx, 1, error);
437 		return error;
438 	}
439 
440 	error = i2c_smbus_write_block_data(client,
441 					   ETP_SMBUS_WRITE_FW_BLOCK,
442 					   ETP_FW_PAGE_SIZE / 2,
443 					   page + ETP_FW_PAGE_SIZE / 2);
444 	if (error) {
445 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
446 			idx, 2, error);
447 		return error;
448 	}
449 
450 
451 	/* Wait for F/W to update one page ROM data. */
452 	usleep_range(8000, 10000);
453 
454 	error = i2c_smbus_read_block_data(client,
455 					  ETP_SMBUS_IAP_CTRL_CMD, val);
456 	if (error < 0) {
457 		dev_err(dev, "Failed to read IAP write result: %d\n",
458 			error);
459 		return error;
460 	}
461 
462 	result = be16_to_cpup((__be16 *)val);
463 	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
464 		dev_err(dev, "IAP reports failed write: %04hx\n",
465 			result);
466 		return -EIO;
467 	}
468 
469 	return 0;
470 }
471 
472 static int elan_smbus_get_report(struct i2c_client *client, u8 *report)
473 {
474 	int len;
475 
476 	BUILD_BUG_ON(I2C_SMBUS_BLOCK_MAX > ETP_SMBUS_REPORT_LEN);
477 
478 	len = i2c_smbus_read_block_data(client,
479 					ETP_SMBUS_PACKET_QUERY,
480 					&report[ETP_SMBUS_REPORT_OFFSET]);
481 	if (len < 0) {
482 		dev_err(&client->dev, "failed to read report data: %d\n", len);
483 		return len;
484 	}
485 
486 	if (len != ETP_SMBUS_REPORT_LEN) {
487 		dev_err(&client->dev,
488 			"wrong report length (%d vs %d expected)\n",
489 			len, ETP_SMBUS_REPORT_LEN);
490 		return -EIO;
491 	}
492 
493 	return 0;
494 }
495 
496 static int elan_smbus_finish_fw_update(struct i2c_client *client,
497 				       struct completion *fw_completion)
498 {
499 	/* No special handling unlike I2C transport */
500 	return 0;
501 }
502 
503 static int elan_smbus_get_pattern(struct i2c_client *client, u8 *pattern)
504 {
505 	*pattern = 0;
506 	return 0;
507 }
508 
509 const struct elan_transport_ops elan_smbus_ops = {
510 	.initialize		= elan_smbus_initialize,
511 	.sleep_control		= elan_smbus_sleep_control,
512 	.power_control		= elan_smbus_power_control,
513 	.set_mode		= elan_smbus_set_mode,
514 
515 	.calibrate		= elan_smbus_calibrate,
516 	.calibrate_result	= elan_smbus_calibrate_result,
517 
518 	.get_baseline_data	= elan_smbus_get_baseline_data,
519 
520 	.get_version		= elan_smbus_get_version,
521 	.get_sm_version		= elan_smbus_get_sm_version,
522 	.get_product_id		= elan_smbus_get_product_id,
523 	.get_checksum		= elan_smbus_get_checksum,
524 	.get_pressure_adjustment = elan_smbus_get_pressure_adjustment,
525 
526 	.get_max		= elan_smbus_get_max,
527 	.get_resolution		= elan_smbus_get_resolution,
528 	.get_num_traces		= elan_smbus_get_num_traces,
529 
530 	.iap_get_mode		= elan_smbus_iap_get_mode,
531 	.iap_reset		= elan_smbus_iap_reset,
532 
533 	.prepare_fw_update	= elan_smbus_prepare_fw_update,
534 	.write_fw_block		= elan_smbus_write_fw_block,
535 	.finish_fw_update	= elan_smbus_finish_fw_update,
536 
537 	.get_report		= elan_smbus_get_report,
538 	.get_pattern		= elan_smbus_get_pattern,
539 };
540