1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) ST-Ericsson SA 2010
4 * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
5 */
6
7 #include <linux/bitops.h>
8 #include <linux/delay.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/i2c.h>
11 #include <linux/input.h>
12 #include <linux/input/mt.h>
13 #include <linux/input/touchscreen.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/property.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21
22 #define MAX_FINGERS 2
23 #define RESET_DELAY 30
24 #define PENUP_TIMEOUT (10)
25 #define DELTA_MIN 16
26 #define MASK_BITS 0x03
27 #define SHIFT_8 8
28 #define SHIFT_2 2
29 #define LENGTH_OF_BUFFER 11
30 #define I2C_RETRY_COUNT 5
31
32 #define BU21013_SENSORS_BTN_0_7_REG 0x70
33 #define BU21013_SENSORS_BTN_8_15_REG 0x71
34 #define BU21013_SENSORS_BTN_16_23_REG 0x72
35 #define BU21013_X1_POS_MSB_REG 0x73
36 #define BU21013_X1_POS_LSB_REG 0x74
37 #define BU21013_Y1_POS_MSB_REG 0x75
38 #define BU21013_Y1_POS_LSB_REG 0x76
39 #define BU21013_X2_POS_MSB_REG 0x77
40 #define BU21013_X2_POS_LSB_REG 0x78
41 #define BU21013_Y2_POS_MSB_REG 0x79
42 #define BU21013_Y2_POS_LSB_REG 0x7A
43 #define BU21013_INT_CLR_REG 0xE8
44 #define BU21013_INT_MODE_REG 0xE9
45 #define BU21013_GAIN_REG 0xEA
46 #define BU21013_OFFSET_MODE_REG 0xEB
47 #define BU21013_XY_EDGE_REG 0xEC
48 #define BU21013_RESET_REG 0xED
49 #define BU21013_CALIB_REG 0xEE
50 #define BU21013_DONE_REG 0xEF
51 #define BU21013_SENSOR_0_7_REG 0xF0
52 #define BU21013_SENSOR_8_15_REG 0xF1
53 #define BU21013_SENSOR_16_23_REG 0xF2
54 #define BU21013_POS_MODE1_REG 0xF3
55 #define BU21013_POS_MODE2_REG 0xF4
56 #define BU21013_CLK_MODE_REG 0xF5
57 #define BU21013_IDLE_REG 0xFA
58 #define BU21013_FILTER_REG 0xFB
59 #define BU21013_TH_ON_REG 0xFC
60 #define BU21013_TH_OFF_REG 0xFD
61
62
63 #define BU21013_RESET_ENABLE 0x01
64
65 #define BU21013_SENSORS_EN_0_7 0x3F
66 #define BU21013_SENSORS_EN_8_15 0xFC
67 #define BU21013_SENSORS_EN_16_23 0x1F
68
69 #define BU21013_POS_MODE1_0 0x02
70 #define BU21013_POS_MODE1_1 0x04
71 #define BU21013_POS_MODE1_2 0x08
72
73 #define BU21013_POS_MODE2_ZERO 0x01
74 #define BU21013_POS_MODE2_AVG1 0x02
75 #define BU21013_POS_MODE2_AVG2 0x04
76 #define BU21013_POS_MODE2_EN_XY 0x08
77 #define BU21013_POS_MODE2_EN_RAW 0x10
78 #define BU21013_POS_MODE2_MULTI 0x80
79
80 #define BU21013_CLK_MODE_DIV 0x01
81 #define BU21013_CLK_MODE_EXT 0x02
82 #define BU21013_CLK_MODE_CALIB 0x80
83
84 #define BU21013_IDLET_0 0x01
85 #define BU21013_IDLET_1 0x02
86 #define BU21013_IDLET_2 0x04
87 #define BU21013_IDLET_3 0x08
88 #define BU21013_IDLE_INTERMIT_EN 0x10
89
90 #define BU21013_DELTA_0_6 0x7F
91 #define BU21013_FILTER_EN 0x80
92
93 #define BU21013_INT_MODE_LEVEL 0x00
94 #define BU21013_INT_MODE_EDGE 0x01
95
96 #define BU21013_GAIN_0 0x01
97 #define BU21013_GAIN_1 0x02
98 #define BU21013_GAIN_2 0x04
99
100 #define BU21013_OFFSET_MODE_DEFAULT 0x00
101 #define BU21013_OFFSET_MODE_MOVE 0x01
102 #define BU21013_OFFSET_MODE_DISABLE 0x02
103
104 #define BU21013_TH_ON_0 0x01
105 #define BU21013_TH_ON_1 0x02
106 #define BU21013_TH_ON_2 0x04
107 #define BU21013_TH_ON_3 0x08
108 #define BU21013_TH_ON_4 0x10
109 #define BU21013_TH_ON_5 0x20
110 #define BU21013_TH_ON_6 0x40
111 #define BU21013_TH_ON_7 0x80
112 #define BU21013_TH_ON_MAX 0xFF
113
114 #define BU21013_TH_OFF_0 0x01
115 #define BU21013_TH_OFF_1 0x02
116 #define BU21013_TH_OFF_2 0x04
117 #define BU21013_TH_OFF_3 0x08
118 #define BU21013_TH_OFF_4 0x10
119 #define BU21013_TH_OFF_5 0x20
120 #define BU21013_TH_OFF_6 0x40
121 #define BU21013_TH_OFF_7 0x80
122 #define BU21013_TH_OFF_MAX 0xFF
123
124 #define BU21013_X_EDGE_0 0x01
125 #define BU21013_X_EDGE_1 0x02
126 #define BU21013_X_EDGE_2 0x04
127 #define BU21013_X_EDGE_3 0x08
128 #define BU21013_Y_EDGE_0 0x10
129 #define BU21013_Y_EDGE_1 0x20
130 #define BU21013_Y_EDGE_2 0x40
131 #define BU21013_Y_EDGE_3 0x80
132
133 #define BU21013_DONE 0x01
134 #define BU21013_NUMBER_OF_X_SENSORS (6)
135 #define BU21013_NUMBER_OF_Y_SENSORS (11)
136
137 #define DRIVER_TP "bu21013_tp"
138
139 /**
140 * struct bu21013_ts - touch panel data structure
141 * @client: pointer to the i2c client
142 * @in_dev: pointer to the input device structure
143 * @props: the device coordinate transformation properties
144 * @regulator: pointer to the Regulator used for touch screen
145 * @cs_gpiod: chip select GPIO line
146 * @int_gpiod: touch interrupt GPIO line
147 * @touch_x_max: maximum X coordinate reported by the device
148 * @touch_y_max: maximum Y coordinate reported by the device
149 * @x_flip: indicates that the driver should invert X coordinate before
150 * reporting
151 * @y_flip: indicates that the driver should invert Y coordinate before
152 * reporting
153 * @touch_stopped: touch stop flag
154 *
155 * Touch panel device data structure
156 */
157 struct bu21013_ts {
158 struct i2c_client *client;
159 struct input_dev *in_dev;
160 struct touchscreen_properties props;
161 struct regulator *regulator;
162 struct gpio_desc *cs_gpiod;
163 struct gpio_desc *int_gpiod;
164 u32 touch_x_max;
165 u32 touch_y_max;
166 bool x_flip;
167 bool y_flip;
168 bool touch_stopped;
169 };
170
bu21013_read_block_data(struct bu21013_ts * ts,u8 * buf)171 static int bu21013_read_block_data(struct bu21013_ts *ts, u8 *buf)
172 {
173 int ret, i;
174
175 for (i = 0; i < I2C_RETRY_COUNT; i++) {
176 ret = i2c_smbus_read_i2c_block_data(ts->client,
177 BU21013_SENSORS_BTN_0_7_REG,
178 LENGTH_OF_BUFFER, buf);
179 if (ret == LENGTH_OF_BUFFER)
180 return 0;
181 }
182
183 return -EINVAL;
184 }
185
bu21013_do_touch_report(struct bu21013_ts * ts)186 static int bu21013_do_touch_report(struct bu21013_ts *ts)
187 {
188 struct input_dev *input = ts->in_dev;
189 struct input_mt_pos pos[MAX_FINGERS];
190 int slots[MAX_FINGERS];
191 u8 buf[LENGTH_OF_BUFFER];
192 bool has_x_sensors, has_y_sensors;
193 int finger_down_count = 0;
194 int i;
195
196 if (bu21013_read_block_data(ts, buf) < 0)
197 return -EINVAL;
198
199 has_x_sensors = hweight32(buf[0] & BU21013_SENSORS_EN_0_7);
200 has_y_sensors = hweight32(((buf[1] & BU21013_SENSORS_EN_8_15) |
201 ((buf[2] & BU21013_SENSORS_EN_16_23) << SHIFT_8)) >> SHIFT_2);
202 if (!has_x_sensors || !has_y_sensors)
203 return 0;
204
205 for (i = 0; i < MAX_FINGERS; i++) {
206 const u8 *data = &buf[4 * i + 3];
207 unsigned int x, y;
208
209 x = data[0] << SHIFT_2 | (data[1] & MASK_BITS);
210 y = data[2] << SHIFT_2 | (data[3] & MASK_BITS);
211 if (x != 0 && y != 0)
212 touchscreen_set_mt_pos(&pos[finger_down_count++],
213 &ts->props, x, y);
214 }
215
216 if (finger_down_count == 2 &&
217 (abs(pos[0].x - pos[1].x) < DELTA_MIN ||
218 abs(pos[0].y - pos[1].y) < DELTA_MIN)) {
219 return 0;
220 }
221
222 input_mt_assign_slots(input, slots, pos, finger_down_count, DELTA_MIN);
223 for (i = 0; i < finger_down_count; i++) {
224 input_mt_slot(input, slots[i]);
225 input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
226 input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
227 input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
228 }
229
230 input_mt_sync_frame(input);
231 input_sync(input);
232
233 return 0;
234 }
235
bu21013_gpio_irq(int irq,void * device_data)236 static irqreturn_t bu21013_gpio_irq(int irq, void *device_data)
237 {
238 struct bu21013_ts *ts = device_data;
239 int keep_polling;
240 int error;
241
242 do {
243 error = bu21013_do_touch_report(ts);
244 if (error) {
245 dev_err(&ts->client->dev, "%s failed\n", __func__);
246 break;
247 }
248
249 if (unlikely(ts->touch_stopped))
250 break;
251
252 keep_polling = ts->int_gpiod ?
253 gpiod_get_value(ts->int_gpiod) : false;
254 if (keep_polling)
255 usleep_range(2000, 2500);
256 } while (keep_polling);
257
258 return IRQ_HANDLED;
259 }
260
bu21013_init_chip(struct bu21013_ts * ts)261 static int bu21013_init_chip(struct bu21013_ts *ts)
262 {
263 struct i2c_client *client = ts->client;
264 int error;
265
266 error = i2c_smbus_write_byte_data(client, BU21013_RESET_REG,
267 BU21013_RESET_ENABLE);
268 if (error) {
269 dev_err(&client->dev, "BU21013_RESET reg write failed\n");
270 return error;
271 }
272 msleep(RESET_DELAY);
273
274 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_0_7_REG,
275 BU21013_SENSORS_EN_0_7);
276 if (error) {
277 dev_err(&client->dev, "BU21013_SENSOR_0_7 reg write failed\n");
278 return error;
279 }
280
281 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_8_15_REG,
282 BU21013_SENSORS_EN_8_15);
283 if (error) {
284 dev_err(&client->dev, "BU21013_SENSOR_8_15 reg write failed\n");
285 return error;
286 }
287
288 error = i2c_smbus_write_byte_data(client, BU21013_SENSOR_16_23_REG,
289 BU21013_SENSORS_EN_16_23);
290 if (error) {
291 dev_err(&client->dev, "BU21013_SENSOR_16_23 reg write failed\n");
292 return error;
293 }
294
295 error = i2c_smbus_write_byte_data(client, BU21013_POS_MODE1_REG,
296 BU21013_POS_MODE1_0 |
297 BU21013_POS_MODE1_1);
298 if (error) {
299 dev_err(&client->dev, "BU21013_POS_MODE1 reg write failed\n");
300 return error;
301 }
302
303 error = i2c_smbus_write_byte_data(client, BU21013_POS_MODE2_REG,
304 BU21013_POS_MODE2_ZERO |
305 BU21013_POS_MODE2_AVG1 |
306 BU21013_POS_MODE2_AVG2 |
307 BU21013_POS_MODE2_EN_RAW |
308 BU21013_POS_MODE2_MULTI);
309 if (error) {
310 dev_err(&client->dev, "BU21013_POS_MODE2 reg write failed\n");
311 return error;
312 }
313
314 error = i2c_smbus_write_byte_data(client, BU21013_CLK_MODE_REG,
315 BU21013_CLK_MODE_DIV |
316 BU21013_CLK_MODE_CALIB);
317 if (error) {
318 dev_err(&client->dev, "BU21013_CLK_MODE reg write failed\n");
319 return error;
320 }
321
322 error = i2c_smbus_write_byte_data(client, BU21013_IDLE_REG,
323 BU21013_IDLET_0 |
324 BU21013_IDLE_INTERMIT_EN);
325 if (error) {
326 dev_err(&client->dev, "BU21013_IDLE reg write failed\n");
327 return error;
328 }
329
330 error = i2c_smbus_write_byte_data(client, BU21013_INT_MODE_REG,
331 BU21013_INT_MODE_LEVEL);
332 if (error) {
333 dev_err(&client->dev, "BU21013_INT_MODE reg write failed\n");
334 return error;
335 }
336
337 error = i2c_smbus_write_byte_data(client, BU21013_FILTER_REG,
338 BU21013_DELTA_0_6 |
339 BU21013_FILTER_EN);
340 if (error) {
341 dev_err(&client->dev, "BU21013_FILTER reg write failed\n");
342 return error;
343 }
344
345 error = i2c_smbus_write_byte_data(client, BU21013_TH_ON_REG,
346 BU21013_TH_ON_5);
347 if (error) {
348 dev_err(&client->dev, "BU21013_TH_ON reg write failed\n");
349 return error;
350 }
351
352 error = i2c_smbus_write_byte_data(client, BU21013_TH_OFF_REG,
353 BU21013_TH_OFF_4 | BU21013_TH_OFF_3);
354 if (error) {
355 dev_err(&client->dev, "BU21013_TH_OFF reg write failed\n");
356 return error;
357 }
358
359 error = i2c_smbus_write_byte_data(client, BU21013_GAIN_REG,
360 BU21013_GAIN_0 | BU21013_GAIN_1);
361 if (error) {
362 dev_err(&client->dev, "BU21013_GAIN reg write failed\n");
363 return error;
364 }
365
366 error = i2c_smbus_write_byte_data(client, BU21013_OFFSET_MODE_REG,
367 BU21013_OFFSET_MODE_DEFAULT);
368 if (error) {
369 dev_err(&client->dev, "BU21013_OFFSET_MODE reg write failed\n");
370 return error;
371 }
372
373 error = i2c_smbus_write_byte_data(client, BU21013_XY_EDGE_REG,
374 BU21013_X_EDGE_0 |
375 BU21013_X_EDGE_2 |
376 BU21013_Y_EDGE_1 |
377 BU21013_Y_EDGE_3);
378 if (error) {
379 dev_err(&client->dev, "BU21013_XY_EDGE reg write failed\n");
380 return error;
381 }
382
383 error = i2c_smbus_write_byte_data(client, BU21013_DONE_REG,
384 BU21013_DONE);
385 if (error) {
386 dev_err(&client->dev, "BU21013_REG_DONE reg write failed\n");
387 return error;
388 }
389
390 return 0;
391 }
392
bu21013_power_off(void * _ts)393 static void bu21013_power_off(void *_ts)
394 {
395 struct bu21013_ts *ts = _ts;
396
397 regulator_disable(ts->regulator);
398 }
399
bu21013_disable_chip(void * _ts)400 static void bu21013_disable_chip(void *_ts)
401 {
402 struct bu21013_ts *ts = _ts;
403
404 gpiod_set_value(ts->cs_gpiod, 0);
405 }
406
bu21013_probe(struct i2c_client * client)407 static int bu21013_probe(struct i2c_client *client)
408 {
409 struct bu21013_ts *ts;
410 struct input_dev *in_dev;
411 struct input_absinfo *info;
412 u32 max_x = 0, max_y = 0;
413 struct device *dev = &client->dev;
414 int error;
415
416 if (!i2c_check_functionality(client->adapter,
417 I2C_FUNC_SMBUS_BYTE_DATA)) {
418 dev_err(dev, "i2c smbus byte data not supported\n");
419 return -EIO;
420 }
421
422 if (!client->irq) {
423 dev_err(dev, "No IRQ set up\n");
424 return -EINVAL;
425 }
426
427 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
428 if (!ts)
429 return -ENOMEM;
430
431 ts->client = client;
432
433 ts->x_flip = device_property_read_bool(dev, "rohm,flip-x");
434 ts->y_flip = device_property_read_bool(dev, "rohm,flip-y");
435
436 in_dev = devm_input_allocate_device(dev);
437 if (!in_dev) {
438 dev_err(dev, "device memory alloc failed\n");
439 return -ENOMEM;
440 }
441 ts->in_dev = in_dev;
442 input_set_drvdata(in_dev, ts);
443
444 /* register the device to input subsystem */
445 in_dev->name = DRIVER_TP;
446 in_dev->id.bustype = BUS_I2C;
447
448 device_property_read_u32(dev, "rohm,touch-max-x", &max_x);
449 device_property_read_u32(dev, "rohm,touch-max-y", &max_y);
450
451 input_set_abs_params(in_dev, ABS_MT_POSITION_X, 0, max_x, 0, 0);
452 input_set_abs_params(in_dev, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
453
454 touchscreen_parse_properties(in_dev, true, &ts->props);
455
456 /* Adjust for the legacy "flip" properties, if present */
457 if (!ts->props.invert_x &&
458 device_property_read_bool(dev, "rohm,flip-x")) {
459 info = &in_dev->absinfo[ABS_MT_POSITION_X];
460 info->maximum -= info->minimum;
461 info->minimum = 0;
462 }
463
464 if (!ts->props.invert_y &&
465 device_property_read_bool(dev, "rohm,flip-y")) {
466 info = &in_dev->absinfo[ABS_MT_POSITION_Y];
467 info->maximum -= info->minimum;
468 info->minimum = 0;
469 }
470
471 error = input_mt_init_slots(in_dev, MAX_FINGERS,
472 INPUT_MT_DIRECT | INPUT_MT_TRACK |
473 INPUT_MT_DROP_UNUSED);
474 if (error) {
475 dev_err(dev, "failed to initialize MT slots");
476 return error;
477 }
478
479 ts->regulator = devm_regulator_get(dev, "avdd");
480 if (IS_ERR(ts->regulator)) {
481 dev_err(dev, "regulator_get failed\n");
482 return PTR_ERR(ts->regulator);
483 }
484
485 error = regulator_enable(ts->regulator);
486 if (error) {
487 dev_err(dev, "regulator enable failed\n");
488 return error;
489 }
490
491 error = devm_add_action_or_reset(dev, bu21013_power_off, ts);
492 if (error) {
493 dev_err(dev, "failed to install power off handler\n");
494 return error;
495 }
496
497 /* Named "CS" on the chip, DT binding is "reset" */
498 ts->cs_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
499 if (IS_ERR(ts->cs_gpiod))
500 return dev_err_probe(dev, PTR_ERR(ts->cs_gpiod), "failed to get CS GPIO\n");
501
502 gpiod_set_consumer_name(ts->cs_gpiod, "BU21013 CS");
503
504 error = devm_add_action_or_reset(dev, bu21013_disable_chip, ts);
505 if (error) {
506 dev_err(dev, "failed to install chip disable handler\n");
507 return error;
508 }
509
510 /* Named "INT" on the chip, DT binding is "touch" */
511 ts->int_gpiod = devm_gpiod_get_optional(dev, "touch", GPIOD_IN);
512 error = PTR_ERR_OR_ZERO(ts->int_gpiod);
513 if (error)
514 return dev_err_probe(dev, error, "failed to get INT GPIO\n");
515
516 if (ts->int_gpiod)
517 gpiod_set_consumer_name(ts->int_gpiod, "BU21013 INT");
518
519 /* configure the touch panel controller */
520 error = bu21013_init_chip(ts);
521 if (error) {
522 dev_err(dev, "error in bu21013 config\n");
523 return error;
524 }
525
526 error = devm_request_threaded_irq(dev, client->irq, NULL, bu21013_gpio_irq,
527 IRQF_ONESHOT, DRIVER_TP, ts);
528 if (error) {
529 dev_err(dev, "request irq %d failed\n", client->irq);
530 return error;
531 }
532
533 error = input_register_device(in_dev);
534 if (error) {
535 dev_err(dev, "failed to register input device\n");
536 return error;
537 }
538
539 i2c_set_clientdata(client, ts);
540
541 return 0;
542 }
543
bu21013_remove(struct i2c_client * client)544 static void bu21013_remove(struct i2c_client *client)
545 {
546 struct bu21013_ts *ts = i2c_get_clientdata(client);
547
548 /* Make sure IRQ will exit quickly even if there is contact */
549 ts->touch_stopped = true;
550 /* The resources will be freed by devm */
551 }
552
bu21013_suspend(struct device * dev)553 static int bu21013_suspend(struct device *dev)
554 {
555 struct i2c_client *client = to_i2c_client(dev);
556 struct bu21013_ts *ts = i2c_get_clientdata(client);
557
558 ts->touch_stopped = true;
559 mb();
560 disable_irq(client->irq);
561
562 if (!device_may_wakeup(&client->dev))
563 regulator_disable(ts->regulator);
564
565 return 0;
566 }
567
bu21013_resume(struct device * dev)568 static int bu21013_resume(struct device *dev)
569 {
570 struct i2c_client *client = to_i2c_client(dev);
571 struct bu21013_ts *ts = i2c_get_clientdata(client);
572 int error;
573
574 if (!device_may_wakeup(&client->dev)) {
575 error = regulator_enable(ts->regulator);
576 if (error) {
577 dev_err(&client->dev,
578 "failed to re-enable regulator when resuming\n");
579 return error;
580 }
581
582 error = bu21013_init_chip(ts);
583 if (error) {
584 dev_err(&client->dev,
585 "failed to reinitialize chip when resuming\n");
586 return error;
587 }
588 }
589
590 ts->touch_stopped = false;
591 mb();
592 enable_irq(client->irq);
593
594 return 0;
595 }
596
597 static DEFINE_SIMPLE_DEV_PM_OPS(bu21013_dev_pm_ops, bu21013_suspend, bu21013_resume);
598
599 static const struct i2c_device_id bu21013_id[] = {
600 { DRIVER_TP },
601 { }
602 };
603 MODULE_DEVICE_TABLE(i2c, bu21013_id);
604
605 static struct i2c_driver bu21013_driver = {
606 .driver = {
607 .name = DRIVER_TP,
608 .pm = pm_sleep_ptr(&bu21013_dev_pm_ops),
609 },
610 .probe = bu21013_probe,
611 .remove = bu21013_remove,
612 .id_table = bu21013_id,
613 };
614
615 module_i2c_driver(bu21013_driver);
616
617 MODULE_LICENSE("GPL v2");
618 MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
619 MODULE_DESCRIPTION("bu21013 touch screen controller driver");
620