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[3];
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[3];
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, u8 *version)
169 {
170 	int error;
171 	u8 val[3];
172 
173 	error = i2c_smbus_read_block_data(client,
174 					  ETP_SMBUS_SM_VERSION_CMD, val);
175 	if (error < 0) {
176 		dev_err(&client->dev, "failed to get SM version: %d\n", error);
177 		return error;
178 	}
179 
180 	*version = val[0]; /* XXX Why 0 and not 2 as in IAP/FW versions? */
181 	return 0;
182 }
183 
184 static int elan_smbus_get_product_id(struct i2c_client *client, u8 *id)
185 {
186 	int error;
187 	u8 val[3];
188 
189 	error = i2c_smbus_read_block_data(client,
190 					  ETP_SMBUS_UNIQUEID_CMD, val);
191 	if (error < 0) {
192 		dev_err(&client->dev, "failed to get product ID: %d\n", error);
193 		return error;
194 	}
195 
196 	*id = val[1];
197 	return 0;
198 }
199 
200 static int elan_smbus_get_checksum(struct i2c_client *client,
201 				   bool iap, u16 *csum)
202 {
203 	int error;
204 	u8 val[3];
205 
206 	error = i2c_smbus_read_block_data(client,
207 					  iap ? ETP_SMBUS_FW_CHECKSUM_CMD :
208 						ETP_SMBUS_IAP_CHECKSUM_CMD,
209 					  val);
210 	if (error < 0) {
211 		dev_err(&client->dev, "failed to get %s checksum: %d\n",
212 			iap ? "IAP" : "FW", error);
213 		return error;
214 	}
215 
216 	*csum = be16_to_cpup((__be16 *)val);
217 	return 0;
218 }
219 
220 static int elan_smbus_get_max(struct i2c_client *client,
221 			      unsigned int *max_x, unsigned int *max_y)
222 {
223 	int error;
224 	u8 val[3];
225 
226 	error = i2c_smbus_read_block_data(client, ETP_SMBUS_RANGE_CMD, val);
227 	if (error) {
228 		dev_err(&client->dev, "failed to get dimensions: %d\n", error);
229 		return error;
230 	}
231 
232 	*max_x = (0x0f & val[0]) << 8 | val[1];
233 	*max_y = (0xf0 & val[0]) << 4 | val[2];
234 
235 	return 0;
236 }
237 
238 static int elan_smbus_get_resolution(struct i2c_client *client,
239 				     u8 *hw_res_x, u8 *hw_res_y)
240 {
241 	int error;
242 	u8 val[3];
243 
244 	error = i2c_smbus_read_block_data(client,
245 					  ETP_SMBUS_RESOLUTION_CMD, val);
246 	if (error) {
247 		dev_err(&client->dev, "failed to get resolution: %d\n", error);
248 		return error;
249 	}
250 
251 	*hw_res_x = val[1] & 0x0F;
252 	*hw_res_y = (val[1] & 0xF0) >> 4;
253 
254 	return 0;
255 }
256 
257 static int elan_smbus_get_num_traces(struct i2c_client *client,
258 				     unsigned int *x_traces,
259 				     unsigned int *y_traces)
260 {
261 	int error;
262 	u8 val[3];
263 
264 	error = i2c_smbus_read_block_data(client,
265 					  ETP_SMBUS_XY_TRACENUM_CMD, val);
266 	if (error) {
267 		dev_err(&client->dev, "failed to get trace info: %d\n", error);
268 		return error;
269 	}
270 
271 	*x_traces = val[1];
272 	*y_traces = val[2];
273 
274 	return 0;
275 }
276 
277 static int elan_smbus_get_pressure_adjustment(struct i2c_client *client,
278 					      int *adjustment)
279 {
280 	*adjustment = ETP_PRESSURE_OFFSET;
281 	return 0;
282 }
283 
284 static int elan_smbus_iap_get_mode(struct i2c_client *client,
285 				   enum tp_mode *mode)
286 {
287 	int error;
288 	u16 constant;
289 	u8 val[3];
290 
291 	error = i2c_smbus_read_block_data(client, ETP_SMBUS_IAP_CTRL_CMD, val);
292 	if (error < 0) {
293 		dev_err(&client->dev, "failed to read iap ctrol register: %d\n",
294 			error);
295 		return error;
296 	}
297 
298 	constant = be16_to_cpup((__be16 *)val);
299 	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
300 
301 	*mode = (constant & ETP_SMBUS_IAP_MODE_ON) ? IAP_MODE : MAIN_MODE;
302 
303 	return 0;
304 }
305 
306 static int elan_smbus_iap_reset(struct i2c_client *client)
307 {
308 	int error;
309 
310 	error = i2c_smbus_write_byte(client, ETP_SMBUS_IAP_RESET_CMD);
311 	if (error) {
312 		dev_err(&client->dev, "cannot reset IC: %d\n", error);
313 		return error;
314 	}
315 
316 	return 0;
317 }
318 
319 static int elan_smbus_set_flash_key(struct i2c_client *client)
320 {
321 	int error;
322 	u8 cmd[4] = { 0x00, 0x0B, 0x00, 0x5A };
323 
324 	error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
325 					   sizeof(cmd), cmd);
326 	if (error) {
327 		dev_err(&client->dev, "cannot set flash key: %d\n", error);
328 		return error;
329 	}
330 
331 	return 0;
332 }
333 
334 static int elan_smbus_prepare_fw_update(struct i2c_client *client)
335 {
336 	struct device *dev = &client->dev;
337 	int len;
338 	int error;
339 	enum tp_mode mode;
340 	u8 val[3];
341 	u8 cmd[4] = {0x0F, 0x78, 0x00, 0x06};
342 	u16 password;
343 
344 	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
345 	error = elan_smbus_iap_get_mode(client, &mode);
346 	if (error)
347 		return error;
348 
349 	if (mode == MAIN_MODE) {
350 
351 		/* set flash key */
352 		error = elan_smbus_set_flash_key(client);
353 		if (error)
354 			return error;
355 
356 		/* write iap password */
357 		if (i2c_smbus_write_byte(client,
358 					 ETP_SMBUS_IAP_PASSWORD_WRITE) < 0) {
359 			dev_err(dev, "cannot write iap password\n");
360 			return -EIO;
361 		}
362 
363 		error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
364 						   sizeof(cmd), cmd);
365 		if (error) {
366 			dev_err(dev, "failed to write iap password: %d\n",
367 				error);
368 			return error;
369 		}
370 
371 		/*
372 		 * Read back password to make sure we enabled flash
373 		 * successfully.
374 		 */
375 		len = i2c_smbus_read_block_data(client,
376 						ETP_SMBUS_IAP_PASSWORD_READ,
377 						val);
378 		if (len < sizeof(u16)) {
379 			error = len < 0 ? len : -EIO;
380 			dev_err(dev, "failed to read iap password: %d\n",
381 				error);
382 			return error;
383 		}
384 
385 		password = be16_to_cpup((__be16 *)val);
386 		if (password != ETP_SMBUS_IAP_PASSWORD) {
387 			dev_err(dev, "wrong iap password = 0x%X\n", password);
388 			return -EIO;
389 		}
390 
391 		/* Wait 30ms for MAIN_MODE change to IAP_MODE */
392 		msleep(30);
393 	}
394 
395 	error = elan_smbus_set_flash_key(client);
396 	if (error)
397 		return error;
398 
399 	/* Reset IC */
400 	error = elan_smbus_iap_reset(client);
401 	if (error)
402 		return error;
403 
404 	return 0;
405 }
406 
407 
408 static int elan_smbus_write_fw_block(struct i2c_client *client,
409 				     const u8 *page, u16 checksum, int idx)
410 {
411 	struct device *dev = &client->dev;
412 	int error;
413 	u16 result;
414 	u8 val[3];
415 
416 	/*
417 	 * Due to the limitation of smbus protocol limiting
418 	 * transfer to 32 bytes at a time, we must split block
419 	 * in 2 transfers.
420 	 */
421 	error = i2c_smbus_write_block_data(client,
422 					   ETP_SMBUS_WRITE_FW_BLOCK,
423 					   ETP_FW_PAGE_SIZE / 2,
424 					   page);
425 	if (error) {
426 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
427 			idx, 1, error);
428 		return error;
429 	}
430 
431 	error = i2c_smbus_write_block_data(client,
432 					   ETP_SMBUS_WRITE_FW_BLOCK,
433 					   ETP_FW_PAGE_SIZE / 2,
434 					   page + ETP_FW_PAGE_SIZE / 2);
435 	if (error) {
436 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
437 			idx, 2, error);
438 		return error;
439 	}
440 
441 
442 	/* Wait for F/W to update one page ROM data. */
443 	usleep_range(8000, 10000);
444 
445 	error = i2c_smbus_read_block_data(client,
446 					  ETP_SMBUS_IAP_CTRL_CMD, val);
447 	if (error < 0) {
448 		dev_err(dev, "Failed to read IAP write result: %d\n",
449 			error);
450 		return error;
451 	}
452 
453 	result = be16_to_cpup((__be16 *)val);
454 	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
455 		dev_err(dev, "IAP reports failed write: %04hx\n",
456 			result);
457 		return -EIO;
458 	}
459 
460 	return 0;
461 }
462 
463 static int elan_smbus_get_report(struct i2c_client *client, u8 *report)
464 {
465 	int len;
466 
467 	len = i2c_smbus_read_block_data(client,
468 					ETP_SMBUS_PACKET_QUERY,
469 					&report[ETP_SMBUS_REPORT_OFFSET]);
470 	if (len < 0) {
471 		dev_err(&client->dev, "failed to read report data: %d\n", len);
472 		return len;
473 	}
474 
475 	if (len != ETP_SMBUS_REPORT_LEN) {
476 		dev_err(&client->dev,
477 			"wrong report length (%d vs %d expected)\n",
478 			len, ETP_SMBUS_REPORT_LEN);
479 		return -EIO;
480 	}
481 
482 	return 0;
483 }
484 
485 static int elan_smbus_finish_fw_update(struct i2c_client *client,
486 				       struct completion *fw_completion)
487 {
488 	/* No special handling unlike I2C transport */
489 	return 0;
490 }
491 
492 const struct elan_transport_ops elan_smbus_ops = {
493 	.initialize		= elan_smbus_initialize,
494 	.sleep_control		= elan_smbus_sleep_control,
495 	.power_control		= elan_smbus_power_control,
496 	.set_mode		= elan_smbus_set_mode,
497 
498 	.calibrate		= elan_smbus_calibrate,
499 	.calibrate_result	= elan_smbus_calibrate_result,
500 
501 	.get_baseline_data	= elan_smbus_get_baseline_data,
502 
503 	.get_version		= elan_smbus_get_version,
504 	.get_sm_version		= elan_smbus_get_sm_version,
505 	.get_product_id		= elan_smbus_get_product_id,
506 	.get_checksum		= elan_smbus_get_checksum,
507 	.get_pressure_adjustment = elan_smbus_get_pressure_adjustment,
508 
509 	.get_max		= elan_smbus_get_max,
510 	.get_resolution		= elan_smbus_get_resolution,
511 	.get_num_traces		= elan_smbus_get_num_traces,
512 
513 	.iap_get_mode		= elan_smbus_iap_get_mode,
514 	.iap_reset		= elan_smbus_iap_reset,
515 
516 	.prepare_fw_update	= elan_smbus_prepare_fw_update,
517 	.write_fw_block		= elan_smbus_write_fw_block,
518 	.finish_fw_update	= elan_smbus_finish_fw_update,
519 
520 	.get_report		= elan_smbus_get_report,
521 };
522