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] - 1;
272 	*y_traces = val[2] - 1;
273 
274 	return 0;
275 }
276 
277 static int elan_smbus_iap_get_mode(struct i2c_client *client,
278 				   enum tp_mode *mode)
279 {
280 	int error;
281 	u16 constant;
282 	u8 val[3];
283 
284 	error = i2c_smbus_read_block_data(client, ETP_SMBUS_IAP_CTRL_CMD, val);
285 	if (error < 0) {
286 		dev_err(&client->dev, "failed to read iap ctrol register: %d\n",
287 			error);
288 		return error;
289 	}
290 
291 	constant = be16_to_cpup((__be16 *)val);
292 	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
293 
294 	*mode = (constant & ETP_SMBUS_IAP_MODE_ON) ? IAP_MODE : MAIN_MODE;
295 
296 	return 0;
297 }
298 
299 static int elan_smbus_iap_reset(struct i2c_client *client)
300 {
301 	int error;
302 
303 	error = i2c_smbus_write_byte(client, ETP_SMBUS_IAP_RESET_CMD);
304 	if (error) {
305 		dev_err(&client->dev, "cannot reset IC: %d\n", error);
306 		return error;
307 	}
308 
309 	return 0;
310 }
311 
312 static int elan_smbus_set_flash_key(struct i2c_client *client)
313 {
314 	int error;
315 	u8 cmd[4] = { 0x00, 0x0B, 0x00, 0x5A };
316 
317 	error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
318 					   sizeof(cmd), cmd);
319 	if (error) {
320 		dev_err(&client->dev, "cannot set flash key: %d\n", error);
321 		return error;
322 	}
323 
324 	return 0;
325 }
326 
327 static int elan_smbus_prepare_fw_update(struct i2c_client *client)
328 {
329 	struct device *dev = &client->dev;
330 	int len;
331 	int error;
332 	enum tp_mode mode;
333 	u8 val[3];
334 	u8 cmd[4] = {0x0F, 0x78, 0x00, 0x06};
335 	u16 password;
336 
337 	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
338 	error = elan_smbus_iap_get_mode(client, &mode);
339 	if (error)
340 		return error;
341 
342 	if (mode == MAIN_MODE) {
343 
344 		/* set flash key */
345 		error = elan_smbus_set_flash_key(client);
346 		if (error)
347 			return error;
348 
349 		/* write iap password */
350 		if (i2c_smbus_write_byte(client,
351 					 ETP_SMBUS_IAP_PASSWORD_WRITE) < 0) {
352 			dev_err(dev, "cannot write iap password\n");
353 			return -EIO;
354 		}
355 
356 		error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
357 						   sizeof(cmd), cmd);
358 		if (error) {
359 			dev_err(dev, "failed to write iap password: %d\n",
360 				error);
361 			return error;
362 		}
363 
364 		/*
365 		 * Read back password to make sure we enabled flash
366 		 * successfully.
367 		 */
368 		len = i2c_smbus_read_block_data(client,
369 						ETP_SMBUS_IAP_PASSWORD_READ,
370 						val);
371 		if (len < sizeof(u16)) {
372 			error = len < 0 ? len : -EIO;
373 			dev_err(dev, "failed to read iap password: %d\n",
374 				error);
375 			return error;
376 		}
377 
378 		password = be16_to_cpup((__be16 *)val);
379 		if (password != ETP_SMBUS_IAP_PASSWORD) {
380 			dev_err(dev, "wrong iap password = 0x%X\n", password);
381 			return -EIO;
382 		}
383 
384 		/* Wait 30ms for MAIN_MODE change to IAP_MODE */
385 		msleep(30);
386 	}
387 
388 	error = elan_smbus_set_flash_key(client);
389 	if (error)
390 		return error;
391 
392 	/* Reset IC */
393 	error = elan_smbus_iap_reset(client);
394 	if (error)
395 		return error;
396 
397 	return 0;
398 }
399 
400 
401 static int elan_smbus_write_fw_block(struct i2c_client *client,
402 				     const u8 *page, u16 checksum, int idx)
403 {
404 	struct device *dev = &client->dev;
405 	int error;
406 	u16 result;
407 	u8 val[3];
408 
409 	/*
410 	 * Due to the limitation of smbus protocol limiting
411 	 * transfer to 32 bytes at a time, we must split block
412 	 * in 2 transfers.
413 	 */
414 	error = i2c_smbus_write_block_data(client,
415 					   ETP_SMBUS_WRITE_FW_BLOCK,
416 					   ETP_FW_PAGE_SIZE / 2,
417 					   page);
418 	if (error) {
419 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
420 			idx, 1, error);
421 		return error;
422 	}
423 
424 	error = i2c_smbus_write_block_data(client,
425 					   ETP_SMBUS_WRITE_FW_BLOCK,
426 					   ETP_FW_PAGE_SIZE / 2,
427 					   page + ETP_FW_PAGE_SIZE / 2);
428 	if (error) {
429 		dev_err(dev, "Failed to write page %d (part %d): %d\n",
430 			idx, 2, error);
431 		return error;
432 	}
433 
434 
435 	/* Wait for F/W to update one page ROM data. */
436 	usleep_range(8000, 10000);
437 
438 	error = i2c_smbus_read_block_data(client,
439 					  ETP_SMBUS_IAP_CTRL_CMD, val);
440 	if (error < 0) {
441 		dev_err(dev, "Failed to read IAP write result: %d\n",
442 			error);
443 		return error;
444 	}
445 
446 	result = be16_to_cpup((__be16 *)val);
447 	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
448 		dev_err(dev, "IAP reports failed write: %04hx\n",
449 			result);
450 		return -EIO;
451 	}
452 
453 	return 0;
454 }
455 
456 static int elan_smbus_get_report(struct i2c_client *client, u8 *report)
457 {
458 	int len;
459 
460 	len = i2c_smbus_read_block_data(client,
461 					ETP_SMBUS_PACKET_QUERY,
462 					&report[ETP_SMBUS_REPORT_OFFSET]);
463 	if (len < 0) {
464 		dev_err(&client->dev, "failed to read report data: %d\n", len);
465 		return len;
466 	}
467 
468 	if (len != ETP_SMBUS_REPORT_LEN) {
469 		dev_err(&client->dev,
470 			"wrong report length (%d vs %d expected)\n",
471 			len, ETP_SMBUS_REPORT_LEN);
472 		return -EIO;
473 	}
474 
475 	return 0;
476 }
477 
478 static int elan_smbus_finish_fw_update(struct i2c_client *client,
479 				       struct completion *fw_completion)
480 {
481 	/* No special handling unlike I2C transport */
482 	return 0;
483 }
484 
485 const struct elan_transport_ops elan_smbus_ops = {
486 	.initialize		= elan_smbus_initialize,
487 	.sleep_control		= elan_smbus_sleep_control,
488 	.power_control		= elan_smbus_power_control,
489 	.set_mode		= elan_smbus_set_mode,
490 
491 	.calibrate		= elan_smbus_calibrate,
492 	.calibrate_result	= elan_smbus_calibrate_result,
493 
494 	.get_baseline_data	= elan_smbus_get_baseline_data,
495 
496 	.get_version		= elan_smbus_get_version,
497 	.get_sm_version		= elan_smbus_get_sm_version,
498 	.get_product_id		= elan_smbus_get_product_id,
499 	.get_checksum		= elan_smbus_get_checksum,
500 
501 	.get_max		= elan_smbus_get_max,
502 	.get_resolution		= elan_smbus_get_resolution,
503 	.get_num_traces		= elan_smbus_get_num_traces,
504 
505 	.iap_get_mode		= elan_smbus_iap_get_mode,
506 	.iap_reset		= elan_smbus_iap_reset,
507 
508 	.prepare_fw_update	= elan_smbus_prepare_fw_update,
509 	.write_fw_block		= elan_smbus_write_fw_block,
510 	.finish_fw_update	= elan_smbus_finish_fw_update,
511 
512 	.get_report		= elan_smbus_get_report,
513 };
514