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_LEN2 7
49#define ETP_SMBUS_REPORT_OFFSET 2
50#define ETP_SMBUS_HELLOPACKET_LEN 5
51#define ETP_SMBUS_IAP_PASSWORD 0x1234
52#define ETP_SMBUS_IAP_MODE_ON (1 << 6)
53
54static int elan_smbus_initialize(struct i2c_client *client)
55{
56 u8 check[ETP_SMBUS_HELLOPACKET_LEN] = { 0x55, 0x55, 0x55, 0x55, 0x55 };
57 u8 values[I2C_SMBUS_BLOCK_MAX] = {0};
58 int len, error;
59
60 /* Get hello packet */
61 len = i2c_smbus_read_block_data(client,
62 ETP_SMBUS_HELLOPACKET_CMD, values);
63 if (len != ETP_SMBUS_HELLOPACKET_LEN) {
64 dev_err(&client->dev, "hello packet length fail: %d\n", len);
65 error = len < 0 ? len : -EIO;
66 return error;
67 }
68
69 /* compare hello packet */
70 if (memcmp(p: values, q: check, ETP_SMBUS_HELLOPACKET_LEN)) {
71 dev_err(&client->dev, "hello packet fail [%*ph]\n",
72 ETP_SMBUS_HELLOPACKET_LEN, values);
73 return -ENXIO;
74 }
75
76 /* enable tp */
77 error = i2c_smbus_write_byte(client, ETP_SMBUS_ENABLE_TP);
78 if (error) {
79 dev_err(&client->dev, "failed to enable touchpad: %d\n", error);
80 return error;
81 }
82
83 return 0;
84}
85
86static int elan_smbus_set_mode(struct i2c_client *client, u8 mode)
87{
88 u8 cmd[4] = { 0x00, 0x07, 0x00, mode };
89
90 return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
91 length: sizeof(cmd), values: cmd);
92}
93
94static int elan_smbus_sleep_control(struct i2c_client *client, bool sleep)
95{
96 if (sleep)
97 return i2c_smbus_write_byte(client, ETP_SMBUS_SLEEP_CMD);
98 else
99 return 0; /* XXX should we send ETP_SMBUS_ENABLE_TP here? */
100}
101
102static int elan_smbus_power_control(struct i2c_client *client, bool enable)
103{
104 return 0; /* A no-op */
105}
106
107static int elan_smbus_calibrate(struct i2c_client *client)
108{
109 u8 cmd[4] = { 0x00, 0x08, 0x00, 0x01 };
110
111 return i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
112 length: sizeof(cmd), values: cmd);
113}
114
115static int elan_smbus_calibrate_result(struct i2c_client *client, u8 *val)
116{
117 int error;
118 u8 buf[I2C_SMBUS_BLOCK_MAX] = {0};
119
120 BUILD_BUG_ON(ETP_CALIBRATE_MAX_LEN > sizeof(buf));
121
122 error = i2c_smbus_read_block_data(client,
123 ETP_SMBUS_CALIBRATE_QUERY, values: buf);
124 if (error < 0)
125 return error;
126
127 memcpy(val, buf, ETP_CALIBRATE_MAX_LEN);
128 return 0;
129}
130
131static int elan_smbus_get_baseline_data(struct i2c_client *client,
132 bool max_baseline, u8 *value)
133{
134 int error;
135 u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
136
137 error = i2c_smbus_read_block_data(client,
138 command: max_baseline ?
139 ETP_SMBUS_MAX_BASELINE_CMD :
140 ETP_SMBUS_MIN_BASELINE_CMD,
141 values: val);
142 if (error < 0)
143 return error;
144
145 *value = be16_to_cpup(p: (__be16 *)val);
146
147 return 0;
148}
149
150static int elan_smbus_get_version(struct i2c_client *client,
151 u8 pattern, bool iap, u8 *version)
152{
153 int error;
154 u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
155
156 error = i2c_smbus_read_block_data(client,
157 command: iap ? ETP_SMBUS_IAP_VERSION_CMD :
158 ETP_SMBUS_FW_VERSION_CMD,
159 values: val);
160 if (error < 0) {
161 dev_err(&client->dev, "failed to get %s version: %d\n",
162 iap ? "IAP" : "FW", error);
163 return error;
164 }
165
166 *version = val[2];
167 return 0;
168}
169
170static int elan_smbus_get_sm_version(struct i2c_client *client, u8 pattern,
171 u16 *ic_type, u8 *version, 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, values: 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
189static 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, values: 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(p: (__be16 *)val);
202 return 0;
203}
204
205static 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 command: iap ? ETP_SMBUS_FW_CHECKSUM_CMD :
213 ETP_SMBUS_IAP_CHECKSUM_CMD,
214 values: 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(p: (__be16 *)val);
222 return 0;
223}
224
225static 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, values: 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
245static 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, values: 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
265static 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, values: 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
286static int elan_smbus_get_pressure_adjustment(struct i2c_client *client,
287 int *adjustment)
288{
289 *adjustment = ETP_PRESSURE_OFFSET;
290 return 0;
291}
292
293static 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, values: 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(p: (__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
315static 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
328static 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 length: sizeof(cmd), values: 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
343static int elan_smbus_prepare_fw_update(struct i2c_client *client, u16 ic_type,
344 u8 iap_version, u16 fw_page_size)
345{
346 struct device *dev = &client->dev;
347 int len;
348 int error;
349 enum tp_mode mode;
350 u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
351 u8 cmd[4] = {0x0F, 0x78, 0x00, 0x06};
352 u16 password;
353
354 /* Get FW in which mode (IAP_MODE/MAIN_MODE) */
355 error = elan_smbus_iap_get_mode(client, mode: &mode);
356 if (error)
357 return error;
358
359 if (mode == MAIN_MODE) {
360
361 /* set flash key */
362 error = elan_smbus_set_flash_key(client);
363 if (error)
364 return error;
365
366 /* write iap password */
367 if (i2c_smbus_write_byte(client,
368 ETP_SMBUS_IAP_PASSWORD_WRITE) < 0) {
369 dev_err(dev, "cannot write iap password\n");
370 return -EIO;
371 }
372
373 error = i2c_smbus_write_block_data(client, ETP_SMBUS_IAP_CMD,
374 length: sizeof(cmd), values: cmd);
375 if (error) {
376 dev_err(dev, "failed to write iap password: %d\n",
377 error);
378 return error;
379 }
380
381 /*
382 * Read back password to make sure we enabled flash
383 * successfully.
384 */
385 len = i2c_smbus_read_block_data(client,
386 ETP_SMBUS_IAP_PASSWORD_READ,
387 values: val);
388 if (len < (int)sizeof(u16)) {
389 error = len < 0 ? len : -EIO;
390 dev_err(dev, "failed to read iap password: %d\n",
391 error);
392 return error;
393 }
394
395 password = be16_to_cpup(p: (__be16 *)val);
396 if (password != ETP_SMBUS_IAP_PASSWORD) {
397 dev_err(dev, "wrong iap password = 0x%X\n", password);
398 return -EIO;
399 }
400
401 /* Wait 30ms for MAIN_MODE change to IAP_MODE */
402 msleep(msecs: 30);
403 }
404
405 error = elan_smbus_set_flash_key(client);
406 if (error)
407 return error;
408
409 /* Reset IC */
410 error = elan_smbus_iap_reset(client);
411 if (error)
412 return error;
413
414 return 0;
415}
416
417
418static int elan_smbus_write_fw_block(struct i2c_client *client, u16 fw_page_size,
419 const u8 *page, u16 checksum, int idx)
420{
421 struct device *dev = &client->dev;
422 int error;
423 u16 result;
424 u8 val[I2C_SMBUS_BLOCK_MAX] = {0};
425
426 /*
427 * Due to the limitation of smbus protocol limiting
428 * transfer to 32 bytes at a time, we must split block
429 * in 2 transfers.
430 */
431 error = i2c_smbus_write_block_data(client,
432 ETP_SMBUS_WRITE_FW_BLOCK,
433 length: fw_page_size / 2,
434 values: page);
435 if (error) {
436 dev_err(dev, "Failed to write page %d (part %d): %d\n",
437 idx, 1, error);
438 return error;
439 }
440
441 error = i2c_smbus_write_block_data(client,
442 ETP_SMBUS_WRITE_FW_BLOCK,
443 length: fw_page_size / 2,
444 values: page + fw_page_size / 2);
445 if (error) {
446 dev_err(dev, "Failed to write page %d (part %d): %d\n",
447 idx, 2, error);
448 return error;
449 }
450
451
452 /* Wait for F/W to update one page ROM data. */
453 usleep_range(min: 8000, max: 10000);
454
455 error = i2c_smbus_read_block_data(client,
456 ETP_SMBUS_IAP_CTRL_CMD, values: val);
457 if (error < 0) {
458 dev_err(dev, "Failed to read IAP write result: %d\n",
459 error);
460 return error;
461 }
462
463 result = be16_to_cpup(p: (__be16 *)val);
464 if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
465 dev_err(dev, "IAP reports failed write: %04hx\n",
466 result);
467 return -EIO;
468 }
469
470 return 0;
471}
472
473static int elan_smbus_get_report_features(struct i2c_client *client, u8 pattern,
474 unsigned int *features,
475 unsigned int *report_len)
476{
477 /*
478 * SMBus controllers with pattern 2 lack area info, as newer
479 * high-precision packets use that space for coordinates.
480 */
481 *features = pattern <= 0x01 ? ETP_FEATURE_REPORT_MK : 0;
482 *report_len = ETP_SMBUS_REPORT_LEN;
483 return 0;
484}
485
486static int elan_smbus_get_report(struct i2c_client *client,
487 u8 *report, unsigned int report_len)
488{
489 int len;
490
491 BUILD_BUG_ON(I2C_SMBUS_BLOCK_MAX > ETP_SMBUS_REPORT_LEN);
492
493 len = i2c_smbus_read_block_data(client,
494 ETP_SMBUS_PACKET_QUERY,
495 values: &report[ETP_SMBUS_REPORT_OFFSET]);
496 if (len < 0) {
497 dev_err(&client->dev, "failed to read report data: %d\n", len);
498 return len;
499 }
500
501 if (report[ETP_REPORT_ID_OFFSET] == ETP_TP_REPORT_ID2)
502 report_len = ETP_SMBUS_REPORT_LEN2;
503
504 if (len != report_len) {
505 dev_err(&client->dev,
506 "wrong report length (%d vs %d expected)\n",
507 len, report_len);
508 return -EIO;
509 }
510
511 return 0;
512}
513
514static int elan_smbus_finish_fw_update(struct i2c_client *client,
515 struct completion *fw_completion)
516{
517 /* No special handling unlike I2C transport */
518 return 0;
519}
520
521static int elan_smbus_get_pattern(struct i2c_client *client, u8 *pattern)
522{
523 *pattern = 0;
524 return 0;
525}
526
527const struct elan_transport_ops elan_smbus_ops = {
528 .initialize = elan_smbus_initialize,
529 .sleep_control = elan_smbus_sleep_control,
530 .power_control = elan_smbus_power_control,
531 .set_mode = elan_smbus_set_mode,
532
533 .calibrate = elan_smbus_calibrate,
534 .calibrate_result = elan_smbus_calibrate_result,
535
536 .get_baseline_data = elan_smbus_get_baseline_data,
537
538 .get_version = elan_smbus_get_version,
539 .get_sm_version = elan_smbus_get_sm_version,
540 .get_product_id = elan_smbus_get_product_id,
541 .get_checksum = elan_smbus_get_checksum,
542 .get_pressure_adjustment = elan_smbus_get_pressure_adjustment,
543
544 .get_max = elan_smbus_get_max,
545 .get_resolution = elan_smbus_get_resolution,
546 .get_num_traces = elan_smbus_get_num_traces,
547
548 .iap_get_mode = elan_smbus_iap_get_mode,
549 .iap_reset = elan_smbus_iap_reset,
550
551 .prepare_fw_update = elan_smbus_prepare_fw_update,
552 .write_fw_block = elan_smbus_write_fw_block,
553 .finish_fw_update = elan_smbus_finish_fw_update,
554
555 .get_report_features = elan_smbus_get_report_features,
556 .get_report = elan_smbus_get_report,
557 .get_pattern = elan_smbus_get_pattern,
558};
559

source code of linux/drivers/input/mouse/elan_i2c_smbus.c