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