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 */
157struct 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
171static 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
186static 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
236static 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
261static 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
393static void bu21013_power_off(void *_ts)
394{
395	struct bu21013_ts *ts = _ts;
396
397	regulator_disable(ts->regulator);
398}
399
400static void bu21013_disable_chip(void *_ts)
401{
402	struct bu21013_ts *ts = _ts;
403
404	gpiod_set_value(ts->cs_gpiod, 0);
405}
406
407static 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
544static 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
553static 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
568static 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
597static DEFINE_SIMPLE_DEV_PM_OPS(bu21013_dev_pm_ops, bu21013_suspend, bu21013_resume);
598
599static const struct i2c_device_id bu21013_id[] = {
600	{ DRIVER_TP, 0 },
601	{ }
602};
603MODULE_DEVICE_TABLE(i2c, bu21013_id);
604
605static 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
615module_i2c_driver(bu21013_driver);
616
617MODULE_LICENSE("GPL v2");
618MODULE_AUTHOR("Naveen Kumar G <naveen.gaddipati@stericsson.com>");
619MODULE_DESCRIPTION("bu21013 touch screen controller driver");
620