1 // SPDX-License-Identifier: GPL-2.0-only
2
3 #include <linux/delay.h>
4 #include <linux/i2c.h>
5 #include <linux/input.h>
6 #include <linux/input/mt.h>
7 #include <linux/input/touchscreen.h>
8 #include <linux/interrupt.h>
9 #include <linux/irq.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/regulator/consumer.h>
14 #include <linux/slab.h>
15
16 /* Register Map */
17
18 #define BT541_SWRESET_CMD 0x0000
19 #define BT541_WAKEUP_CMD 0x0001
20
21 #define BT541_IDLE_CMD 0x0004
22 #define BT541_SLEEP_CMD 0x0005
23
24 #define BT541_CLEAR_INT_STATUS_CMD 0x0003
25 #define BT541_CALIBRATE_CMD 0x0006
26 #define BT541_SAVE_STATUS_CMD 0x0007
27 #define BT541_SAVE_CALIBRATION_CMD 0x0008
28 #define BT541_RECALL_FACTORY_CMD 0x000f
29
30 #define BT541_THRESHOLD 0x0020
31
32 #define BT541_LARGE_PALM_REJECT_AREA_TH 0x003F
33
34 #define BT541_DEBUG_REG 0x0115 /* 0~7 */
35
36 #define BT541_TOUCH_MODE 0x0010
37 #define BT541_CHIP_REVISION 0x0011
38 #define BT541_FIRMWARE_VERSION 0x0012
39
40 #define ZINITIX_USB_DETECT 0x116
41
42 #define BT541_MINOR_FW_VERSION 0x0121
43
44 #define BT541_VENDOR_ID 0x001C
45 #define BT541_HW_ID 0x0014
46
47 #define BT541_DATA_VERSION_REG 0x0013
48 #define BT541_SUPPORTED_FINGER_NUM 0x0015
49 #define BT541_EEPROM_INFO 0x0018
50 #define BT541_INITIAL_TOUCH_MODE 0x0019
51
52 #define BT541_TOTAL_NUMBER_OF_X 0x0060
53 #define BT541_TOTAL_NUMBER_OF_Y 0x0061
54
55 #define BT541_DELAY_RAW_FOR_HOST 0x007f
56
57 #define BT541_BUTTON_SUPPORTED_NUM 0x00B0
58 #define BT541_BUTTON_SENSITIVITY 0x00B2
59 #define BT541_DUMMY_BUTTON_SENSITIVITY 0X00C8
60
61 #define BT541_X_RESOLUTION 0x00C0
62 #define BT541_Y_RESOLUTION 0x00C1
63
64 #define BT541_POINT_STATUS_REG 0x0080
65 #define BT541_ICON_STATUS_REG 0x00AA
66
67 #define BT541_POINT_COORD_REG (BT541_POINT_STATUS_REG + 2)
68
69 #define BT541_AFE_FREQUENCY 0x0100
70 #define BT541_DND_N_COUNT 0x0122
71 #define BT541_DND_U_COUNT 0x0135
72
73 #define BT541_RAWDATA_REG 0x0200
74
75 #define BT541_EEPROM_INFO_REG 0x0018
76
77 #define BT541_INT_ENABLE_FLAG 0x00f0
78 #define BT541_PERIODICAL_INTERRUPT_INTERVAL 0x00f1
79
80 #define BT541_BTN_WIDTH 0x016d
81
82 #define BT541_CHECKSUM_RESULT 0x012c
83
84 #define BT541_INIT_FLASH 0x01d0
85 #define BT541_WRITE_FLASH 0x01d1
86 #define BT541_READ_FLASH 0x01d2
87
88 #define ZINITIX_INTERNAL_FLAG_02 0x011e
89 #define ZINITIX_INTERNAL_FLAG_03 0x011f
90
91 #define ZINITIX_I2C_CHECKSUM_WCNT 0x016a
92 #define ZINITIX_I2C_CHECKSUM_RESULT 0x016c
93
94 /* Interrupt & status register flags */
95
96 #define BIT_PT_CNT_CHANGE BIT(0)
97 #define BIT_DOWN BIT(1)
98 #define BIT_MOVE BIT(2)
99 #define BIT_UP BIT(3)
100 #define BIT_PALM BIT(4)
101 #define BIT_PALM_REJECT BIT(5)
102 #define BIT_RESERVED_0 BIT(6)
103 #define BIT_RESERVED_1 BIT(7)
104 #define BIT_WEIGHT_CHANGE BIT(8)
105 #define BIT_PT_NO_CHANGE BIT(9)
106 #define BIT_REJECT BIT(10)
107 #define BIT_PT_EXIST BIT(11)
108 #define BIT_RESERVED_2 BIT(12)
109 #define BIT_ERROR BIT(13)
110 #define BIT_DEBUG BIT(14)
111 #define BIT_ICON_EVENT BIT(15)
112
113 #define SUB_BIT_EXIST BIT(0)
114 #define SUB_BIT_DOWN BIT(1)
115 #define SUB_BIT_MOVE BIT(2)
116 #define SUB_BIT_UP BIT(3)
117 #define SUB_BIT_UPDATE BIT(4)
118 #define SUB_BIT_WAIT BIT(5)
119
120 #define DEFAULT_TOUCH_POINT_MODE 2
121 #define MAX_SUPPORTED_FINGER_NUM 5
122
123 #define CHIP_ON_DELAY 15 // ms
124 #define FIRMWARE_ON_DELAY 40 // ms
125
126 struct point_coord {
127 __le16 x;
128 __le16 y;
129 u8 width;
130 u8 sub_status;
131 // currently unused, but needed as padding:
132 u8 minor_width;
133 u8 angle;
134 };
135
136 struct touch_event {
137 __le16 status;
138 u8 finger_mask;
139 u8 time_stamp;
140 struct point_coord point_coord[MAX_SUPPORTED_FINGER_NUM];
141 };
142
143 struct bt541_ts_data {
144 struct i2c_client *client;
145 struct input_dev *input_dev;
146 struct touchscreen_properties prop;
147 struct regulator_bulk_data supplies[2];
148 u32 zinitix_mode;
149 };
150
zinitix_read_data(struct i2c_client * client,u16 reg,void * values,size_t length)151 static int zinitix_read_data(struct i2c_client *client,
152 u16 reg, void *values, size_t length)
153 {
154 __le16 reg_le = cpu_to_le16(reg);
155 int ret;
156
157 /* A single i2c_transfer() transaction does not work here. */
158 ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le));
159 if (ret != sizeof(reg_le))
160 return ret < 0 ? ret : -EIO;
161
162 ret = i2c_master_recv(client, (u8 *)values, length);
163 if (ret != length)
164 return ret < 0 ? ret : -EIO; ;
165
166 return 0;
167 }
168
zinitix_write_u16(struct i2c_client * client,u16 reg,u16 value)169 static int zinitix_write_u16(struct i2c_client *client, u16 reg, u16 value)
170 {
171 __le16 packet[2] = {cpu_to_le16(reg), cpu_to_le16(value)};
172 int ret;
173
174 ret = i2c_master_send(client, (u8 *)packet, sizeof(packet));
175 if (ret != sizeof(packet))
176 return ret < 0 ? ret : -EIO;
177
178 return 0;
179 }
180
zinitix_write_cmd(struct i2c_client * client,u16 reg)181 static int zinitix_write_cmd(struct i2c_client *client, u16 reg)
182 {
183 __le16 reg_le = cpu_to_le16(reg);
184 int ret;
185
186 ret = i2c_master_send(client, (u8 *)®_le, sizeof(reg_le));
187 if (ret != sizeof(reg_le))
188 return ret < 0 ? ret : -EIO;
189
190 return 0;
191 }
192
zinitix_init_touch(struct bt541_ts_data * bt541)193 static int zinitix_init_touch(struct bt541_ts_data *bt541)
194 {
195 struct i2c_client *client = bt541->client;
196 int i;
197 int error;
198
199 error = zinitix_write_cmd(client, BT541_SWRESET_CMD);
200 if (error) {
201 dev_err(&client->dev, "Failed to write reset command\n");
202 return error;
203 }
204
205 error = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG, 0x0);
206 if (error) {
207 dev_err(&client->dev,
208 "Failed to reset interrupt enable flag\n");
209 return error;
210 }
211
212 /* initialize */
213 error = zinitix_write_u16(client, BT541_X_RESOLUTION,
214 bt541->prop.max_x);
215 if (error)
216 return error;
217
218 error = zinitix_write_u16(client, BT541_Y_RESOLUTION,
219 bt541->prop.max_y);
220 if (error)
221 return error;
222
223 error = zinitix_write_u16(client, BT541_SUPPORTED_FINGER_NUM,
224 MAX_SUPPORTED_FINGER_NUM);
225 if (error)
226 return error;
227
228 error = zinitix_write_u16(client, BT541_INITIAL_TOUCH_MODE,
229 bt541->zinitix_mode);
230 if (error)
231 return error;
232
233 error = zinitix_write_u16(client, BT541_TOUCH_MODE,
234 bt541->zinitix_mode);
235 if (error)
236 return error;
237
238 error = zinitix_write_u16(client, BT541_INT_ENABLE_FLAG,
239 BIT_PT_CNT_CHANGE | BIT_DOWN | BIT_MOVE |
240 BIT_UP);
241 if (error)
242 return error;
243
244 /* clear queue */
245 for (i = 0; i < 10; i++) {
246 zinitix_write_cmd(client, BT541_CLEAR_INT_STATUS_CMD);
247 udelay(10);
248 }
249
250 return 0;
251 }
252
zinitix_init_regulators(struct bt541_ts_data * bt541)253 static int zinitix_init_regulators(struct bt541_ts_data *bt541)
254 {
255 struct i2c_client *client = bt541->client;
256 int error;
257
258 bt541->supplies[0].supply = "vdd";
259 bt541->supplies[1].supply = "vddo";
260 error = devm_regulator_bulk_get(&client->dev,
261 ARRAY_SIZE(bt541->supplies),
262 bt541->supplies);
263 if (error < 0) {
264 dev_err(&client->dev, "Failed to get regulators: %d\n", error);
265 return error;
266 }
267
268 return 0;
269 }
270
zinitix_send_power_on_sequence(struct bt541_ts_data * bt541)271 static int zinitix_send_power_on_sequence(struct bt541_ts_data *bt541)
272 {
273 int error;
274 struct i2c_client *client = bt541->client;
275
276 error = zinitix_write_u16(client, 0xc000, 0x0001);
277 if (error) {
278 dev_err(&client->dev,
279 "Failed to send power sequence(vendor cmd enable)\n");
280 return error;
281 }
282 udelay(10);
283
284 error = zinitix_write_cmd(client, 0xc004);
285 if (error) {
286 dev_err(&client->dev,
287 "Failed to send power sequence (intn clear)\n");
288 return error;
289 }
290 udelay(10);
291
292 error = zinitix_write_u16(client, 0xc002, 0x0001);
293 if (error) {
294 dev_err(&client->dev,
295 "Failed to send power sequence (nvm init)\n");
296 return error;
297 }
298 mdelay(2);
299
300 error = zinitix_write_u16(client, 0xc001, 0x0001);
301 if (error) {
302 dev_err(&client->dev,
303 "Failed to send power sequence (program start)\n");
304 return error;
305 }
306 msleep(FIRMWARE_ON_DELAY);
307
308 return 0;
309 }
310
zinitix_report_finger(struct bt541_ts_data * bt541,int slot,const struct point_coord * p)311 static void zinitix_report_finger(struct bt541_ts_data *bt541, int slot,
312 const struct point_coord *p)
313 {
314 u16 x, y;
315
316 if (unlikely(!(p->sub_status &
317 (SUB_BIT_UP | SUB_BIT_DOWN | SUB_BIT_MOVE)))) {
318 dev_dbg(&bt541->client->dev, "unknown finger event %#02x\n",
319 p->sub_status);
320 return;
321 }
322
323 x = le16_to_cpu(p->x);
324 y = le16_to_cpu(p->y);
325
326 input_mt_slot(bt541->input_dev, slot);
327 if (input_mt_report_slot_state(bt541->input_dev, MT_TOOL_FINGER,
328 !(p->sub_status & SUB_BIT_UP))) {
329 touchscreen_report_pos(bt541->input_dev,
330 &bt541->prop, x, y, true);
331 input_report_abs(bt541->input_dev,
332 ABS_MT_TOUCH_MAJOR, p->width);
333 dev_dbg(&bt541->client->dev, "finger %d %s (%u, %u)\n",
334 slot, p->sub_status & SUB_BIT_DOWN ? "down" : "move",
335 x, y);
336 } else {
337 dev_dbg(&bt541->client->dev, "finger %d up (%u, %u)\n",
338 slot, x, y);
339 }
340 }
341
zinitix_ts_irq_handler(int irq,void * bt541_handler)342 static irqreturn_t zinitix_ts_irq_handler(int irq, void *bt541_handler)
343 {
344 struct bt541_ts_data *bt541 = bt541_handler;
345 struct i2c_client *client = bt541->client;
346 struct touch_event touch_event;
347 unsigned long finger_mask;
348 int error;
349 int i;
350
351 memset(&touch_event, 0, sizeof(struct touch_event));
352
353 error = zinitix_read_data(bt541->client, BT541_POINT_STATUS_REG,
354 &touch_event, sizeof(struct touch_event));
355 if (error) {
356 dev_err(&client->dev, "Failed to read in touchpoint struct\n");
357 goto out;
358 }
359
360 finger_mask = touch_event.finger_mask;
361 for_each_set_bit(i, &finger_mask, MAX_SUPPORTED_FINGER_NUM) {
362 const struct point_coord *p = &touch_event.point_coord[i];
363
364 /* Only process contacts that are actually reported */
365 if (p->sub_status & SUB_BIT_EXIST)
366 zinitix_report_finger(bt541, i, p);
367 }
368
369 input_mt_sync_frame(bt541->input_dev);
370 input_sync(bt541->input_dev);
371
372 out:
373 zinitix_write_cmd(bt541->client, BT541_CLEAR_INT_STATUS_CMD);
374 return IRQ_HANDLED;
375 }
376
zinitix_start(struct bt541_ts_data * bt541)377 static int zinitix_start(struct bt541_ts_data *bt541)
378 {
379 int error;
380
381 error = regulator_bulk_enable(ARRAY_SIZE(bt541->supplies),
382 bt541->supplies);
383 if (error) {
384 dev_err(&bt541->client->dev,
385 "Failed to enable regulators: %d\n", error);
386 return error;
387 }
388
389 msleep(CHIP_ON_DELAY);
390
391 error = zinitix_send_power_on_sequence(bt541);
392 if (error) {
393 dev_err(&bt541->client->dev,
394 "Error while sending power-on sequence: %d\n", error);
395 return error;
396 }
397
398 error = zinitix_init_touch(bt541);
399 if (error) {
400 dev_err(&bt541->client->dev,
401 "Error while configuring touch IC\n");
402 return error;
403 }
404
405 enable_irq(bt541->client->irq);
406
407 return 0;
408 }
409
zinitix_stop(struct bt541_ts_data * bt541)410 static int zinitix_stop(struct bt541_ts_data *bt541)
411 {
412 int error;
413
414 disable_irq(bt541->client->irq);
415
416 error = regulator_bulk_disable(ARRAY_SIZE(bt541->supplies),
417 bt541->supplies);
418 if (error) {
419 dev_err(&bt541->client->dev,
420 "Failed to disable regulators: %d\n", error);
421 return error;
422 }
423
424 return 0;
425 }
426
zinitix_input_open(struct input_dev * dev)427 static int zinitix_input_open(struct input_dev *dev)
428 {
429 struct bt541_ts_data *bt541 = input_get_drvdata(dev);
430
431 return zinitix_start(bt541);
432 }
433
zinitix_input_close(struct input_dev * dev)434 static void zinitix_input_close(struct input_dev *dev)
435 {
436 struct bt541_ts_data *bt541 = input_get_drvdata(dev);
437
438 zinitix_stop(bt541);
439 }
440
zinitix_init_input_dev(struct bt541_ts_data * bt541)441 static int zinitix_init_input_dev(struct bt541_ts_data *bt541)
442 {
443 struct input_dev *input_dev;
444 int error;
445
446 input_dev = devm_input_allocate_device(&bt541->client->dev);
447 if (!input_dev) {
448 dev_err(&bt541->client->dev,
449 "Failed to allocate input device.");
450 return -ENOMEM;
451 }
452
453 input_set_drvdata(input_dev, bt541);
454 bt541->input_dev = input_dev;
455
456 input_dev->name = "Zinitix Capacitive TouchScreen";
457 input_dev->phys = "input/ts";
458 input_dev->id.bustype = BUS_I2C;
459 input_dev->open = zinitix_input_open;
460 input_dev->close = zinitix_input_close;
461
462 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
463 input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
464 input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
465 input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
466
467 touchscreen_parse_properties(input_dev, true, &bt541->prop);
468 if (!bt541->prop.max_x || !bt541->prop.max_y) {
469 dev_err(&bt541->client->dev,
470 "Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
471 return -EINVAL;
472 }
473
474 error = input_mt_init_slots(input_dev, MAX_SUPPORTED_FINGER_NUM,
475 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
476 if (error) {
477 dev_err(&bt541->client->dev,
478 "Failed to initialize MT slots: %d", error);
479 return error;
480 }
481
482 error = input_register_device(input_dev);
483 if (error) {
484 dev_err(&bt541->client->dev,
485 "Failed to register input device: %d", error);
486 return error;
487 }
488
489 return 0;
490 }
491
zinitix_ts_probe(struct i2c_client * client)492 static int zinitix_ts_probe(struct i2c_client *client)
493 {
494 struct bt541_ts_data *bt541;
495 int error;
496
497 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
498 dev_err(&client->dev,
499 "Failed to assert adapter's support for plain I2C.\n");
500 return -ENXIO;
501 }
502
503 bt541 = devm_kzalloc(&client->dev, sizeof(*bt541), GFP_KERNEL);
504 if (!bt541)
505 return -ENOMEM;
506
507 bt541->client = client;
508 i2c_set_clientdata(client, bt541);
509
510 error = zinitix_init_regulators(bt541);
511 if (error) {
512 dev_err(&client->dev,
513 "Failed to initialize regulators: %d\n", error);
514 return error;
515 }
516
517 error = devm_request_threaded_irq(&client->dev, client->irq,
518 NULL, zinitix_ts_irq_handler,
519 IRQF_ONESHOT,
520 client->name, bt541);
521 if (error) {
522 dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
523 return error;
524 }
525
526 error = zinitix_init_input_dev(bt541);
527 if (error) {
528 dev_err(&client->dev,
529 "Failed to initialize input device: %d\n", error);
530 return error;
531 }
532
533 error = device_property_read_u32(&client->dev, "zinitix,mode",
534 &bt541->zinitix_mode);
535 if (error < 0) {
536 /* fall back to mode 2 */
537 bt541->zinitix_mode = DEFAULT_TOUCH_POINT_MODE;
538 }
539
540 if (bt541->zinitix_mode != 2) {
541 /*
542 * If there are devices that don't support mode 2, support
543 * for other modes (0, 1) will be needed.
544 */
545 dev_err(&client->dev,
546 "Malformed zinitix,mode property, must be 2 (supplied: %d)\n",
547 bt541->zinitix_mode);
548 return -EINVAL;
549 }
550
551 irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
552
553 return 0;
554 }
555
zinitix_suspend(struct device * dev)556 static int __maybe_unused zinitix_suspend(struct device *dev)
557 {
558 struct i2c_client *client = to_i2c_client(dev);
559 struct bt541_ts_data *bt541 = i2c_get_clientdata(client);
560
561 mutex_lock(&bt541->input_dev->mutex);
562
563 if (bt541->input_dev->users)
564 zinitix_stop(bt541);
565
566 mutex_unlock(&bt541->input_dev->mutex);
567
568 return 0;
569 }
570
zinitix_resume(struct device * dev)571 static int __maybe_unused zinitix_resume(struct device *dev)
572 {
573 struct i2c_client *client = to_i2c_client(dev);
574 struct bt541_ts_data *bt541 = i2c_get_clientdata(client);
575 int ret = 0;
576
577 mutex_lock(&bt541->input_dev->mutex);
578
579 if (bt541->input_dev->users)
580 ret = zinitix_start(bt541);
581
582 mutex_unlock(&bt541->input_dev->mutex);
583
584 return ret;
585 }
586
587 static SIMPLE_DEV_PM_OPS(zinitix_pm_ops, zinitix_suspend, zinitix_resume);
588
589 #ifdef CONFIG_OF
590 static const struct of_device_id zinitix_of_match[] = {
591 { .compatible = "zinitix,bt541" },
592 { }
593 };
594 MODULE_DEVICE_TABLE(of, zinitix_of_match);
595 #endif
596
597 static struct i2c_driver zinitix_ts_driver = {
598 .probe_new = zinitix_ts_probe,
599 .driver = {
600 .name = "Zinitix-TS",
601 .pm = &zinitix_pm_ops,
602 .of_match_table = of_match_ptr(zinitix_of_match),
603 },
604 };
605 module_i2c_driver(zinitix_ts_driver);
606
607 MODULE_AUTHOR("Michael Srba <Michael.Srba@seznam.cz>");
608 MODULE_DESCRIPTION("Zinitix touchscreen driver");
609 MODULE_LICENSE("GPL v2");
610