1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for AUO in-cell touchscreens
4 *
5 * Copyright (c) 2011 Heiko Stuebner <heiko@sntech.de>
6 *
7 * loosely based on auo_touch.c from Dell Streak vendor-kernel
8 *
9 * Copyright (c) 2008 QUALCOMM Incorporated.
10 * Copyright (c) 2008 QUALCOMM USA, INC.
11 */
12
13#include <linux/err.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/slab.h>
18#include <linux/input.h>
19#include <linux/jiffies.h>
20#include <linux/i2c.h>
21#include <linux/mutex.h>
22#include <linux/delay.h>
23#include <linux/gpio/consumer.h>
24#include <linux/of.h>
25#include <linux/property.h>
26
27/*
28 * Coordinate calculation:
29 * X1 = X1_LSB + X1_MSB*256
30 * Y1 = Y1_LSB + Y1_MSB*256
31 * X2 = X2_LSB + X2_MSB*256
32 * Y2 = Y2_LSB + Y2_MSB*256
33 */
34#define AUO_PIXCIR_REG_X1_LSB		0x00
35#define AUO_PIXCIR_REG_X1_MSB		0x01
36#define AUO_PIXCIR_REG_Y1_LSB		0x02
37#define AUO_PIXCIR_REG_Y1_MSB		0x03
38#define AUO_PIXCIR_REG_X2_LSB		0x04
39#define AUO_PIXCIR_REG_X2_MSB		0x05
40#define AUO_PIXCIR_REG_Y2_LSB		0x06
41#define AUO_PIXCIR_REG_Y2_MSB		0x07
42
43#define AUO_PIXCIR_REG_STRENGTH		0x0d
44#define AUO_PIXCIR_REG_STRENGTH_X1_LSB	0x0e
45#define AUO_PIXCIR_REG_STRENGTH_X1_MSB	0x0f
46
47#define AUO_PIXCIR_REG_RAW_DATA_X	0x2b
48#define AUO_PIXCIR_REG_RAW_DATA_Y	0x4f
49
50#define AUO_PIXCIR_REG_X_SENSITIVITY	0x6f
51#define AUO_PIXCIR_REG_Y_SENSITIVITY	0x70
52#define AUO_PIXCIR_REG_INT_SETTING	0x71
53#define AUO_PIXCIR_REG_INT_WIDTH	0x72
54#define AUO_PIXCIR_REG_POWER_MODE	0x73
55
56#define AUO_PIXCIR_REG_VERSION		0x77
57#define AUO_PIXCIR_REG_CALIBRATE	0x78
58
59#define AUO_PIXCIR_REG_TOUCHAREA_X1	0x1e
60#define AUO_PIXCIR_REG_TOUCHAREA_Y1	0x1f
61#define AUO_PIXCIR_REG_TOUCHAREA_X2	0x20
62#define AUO_PIXCIR_REG_TOUCHAREA_Y2	0x21
63
64#define AUO_PIXCIR_REG_EEPROM_CALIB_X	0x42
65#define AUO_PIXCIR_REG_EEPROM_CALIB_Y	0xad
66
67#define AUO_PIXCIR_INT_TPNUM_MASK	0xe0
68#define AUO_PIXCIR_INT_TPNUM_SHIFT	5
69#define AUO_PIXCIR_INT_RELEASE		(1 << 4)
70#define AUO_PIXCIR_INT_ENABLE		(1 << 3)
71#define AUO_PIXCIR_INT_POL_HIGH		(1 << 2)
72
73/*
74 * Interrupt modes:
75 * periodical:		interrupt is asserted periodicaly
76 * compare coordinates:	interrupt is asserted when coordinates change
77 * indicate touch:	interrupt is asserted during touch
78 */
79#define AUO_PIXCIR_INT_PERIODICAL	0x00
80#define AUO_PIXCIR_INT_COMP_COORD	0x01
81#define AUO_PIXCIR_INT_TOUCH_IND	0x02
82#define AUO_PIXCIR_INT_MODE_MASK	0x03
83
84/*
85 * Power modes:
86 * active:	scan speed 60Hz
87 * sleep:	scan speed 10Hz can be auto-activated, wakeup on 1st touch
88 * deep sleep:	scan speed 1Hz can only be entered or left manually.
89 */
90#define AUO_PIXCIR_POWER_ACTIVE		0x00
91#define AUO_PIXCIR_POWER_SLEEP		0x01
92#define AUO_PIXCIR_POWER_DEEP_SLEEP	0x02
93#define AUO_PIXCIR_POWER_MASK		0x03
94
95#define AUO_PIXCIR_POWER_ALLOW_SLEEP	(1 << 2)
96#define AUO_PIXCIR_POWER_IDLE_TIME(ms)	((ms & 0xf) << 4)
97
98#define AUO_PIXCIR_CALIBRATE		0x03
99
100#define AUO_PIXCIR_EEPROM_CALIB_X_LEN	62
101#define AUO_PIXCIR_EEPROM_CALIB_Y_LEN	36
102
103#define AUO_PIXCIR_RAW_DATA_X_LEN	18
104#define AUO_PIXCIR_RAW_DATA_Y_LEN	11
105
106#define AUO_PIXCIR_STRENGTH_ENABLE	(1 << 0)
107
108/* Touchscreen absolute values */
109#define AUO_PIXCIR_REPORT_POINTS	2
110#define AUO_PIXCIR_MAX_AREA		0xff
111#define AUO_PIXCIR_PENUP_TIMEOUT_MS	10
112
113struct auo_pixcir_ts {
114	struct i2c_client	*client;
115	struct input_dev	*input;
116	struct gpio_desc	*gpio_int;
117	struct gpio_desc	*gpio_rst;
118	char			phys[32];
119
120	unsigned int		x_max;
121	unsigned int		y_max;
122
123	/* special handling for touch_indicate interrupt mode */
124	bool			touch_ind_mode;
125
126	wait_queue_head_t	wait;
127	bool			stopped;
128};
129
130struct auo_point_t {
131	int	coord_x;
132	int	coord_y;
133	int	area_major;
134	int	area_minor;
135	int	orientation;
136};
137
138static int auo_pixcir_collect_data(struct auo_pixcir_ts *ts,
139				   struct auo_point_t *point)
140{
141	struct i2c_client *client = ts->client;
142	uint8_t raw_coord[8];
143	uint8_t raw_area[4];
144	int i, ret;
145
146	/* touch coordinates */
147	ret = i2c_smbus_read_i2c_block_data(client, AUO_PIXCIR_REG_X1_LSB,
148					    8, raw_coord);
149	if (ret < 0) {
150		dev_err(&client->dev, "failed to read coordinate, %d\n", ret);
151		return ret;
152	}
153
154	/* touch area */
155	ret = i2c_smbus_read_i2c_block_data(client, AUO_PIXCIR_REG_TOUCHAREA_X1,
156					    4, raw_area);
157	if (ret < 0) {
158		dev_err(&client->dev, "could not read touch area, %d\n", ret);
159		return ret;
160	}
161
162	for (i = 0; i < AUO_PIXCIR_REPORT_POINTS; i++) {
163		point[i].coord_x =
164			raw_coord[4 * i + 1] << 8 | raw_coord[4 * i];
165		point[i].coord_y =
166			raw_coord[4 * i + 3] << 8 | raw_coord[4 * i + 2];
167
168		if (point[i].coord_x > ts->x_max ||
169		    point[i].coord_y > ts->y_max) {
170			dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
171				point[i].coord_x, point[i].coord_y);
172			point[i].coord_x = point[i].coord_y = 0;
173		}
174
175		/* determine touch major, minor and orientation */
176		point[i].area_major = max(raw_area[2 * i], raw_area[2 * i + 1]);
177		point[i].area_minor = min(raw_area[2 * i], raw_area[2 * i + 1]);
178		point[i].orientation = raw_area[2 * i] > raw_area[2 * i + 1];
179	}
180
181	return 0;
182}
183
184static irqreturn_t auo_pixcir_interrupt(int irq, void *dev_id)
185{
186	struct auo_pixcir_ts *ts = dev_id;
187	struct auo_point_t point[AUO_PIXCIR_REPORT_POINTS];
188	int i;
189	int ret;
190	int fingers = 0;
191	int abs = -1;
192
193	while (!ts->stopped) {
194
195		/* check for up event in touch touch_ind_mode */
196		if (ts->touch_ind_mode) {
197			if (gpiod_get_value_cansleep(ts->gpio_int) == 0) {
198				input_mt_sync(ts->input);
199				input_report_key(ts->input, BTN_TOUCH, 0);
200				input_sync(ts->input);
201				break;
202			}
203		}
204
205		ret = auo_pixcir_collect_data(ts, point);
206		if (ret < 0) {
207			/* we want to loop only in touch_ind_mode */
208			if (!ts->touch_ind_mode)
209				break;
210
211			wait_event_timeout(ts->wait, ts->stopped,
212				msecs_to_jiffies(AUO_PIXCIR_PENUP_TIMEOUT_MS));
213			continue;
214		}
215
216		for (i = 0; i < AUO_PIXCIR_REPORT_POINTS; i++) {
217			if (point[i].coord_x > 0 || point[i].coord_y > 0) {
218				input_report_abs(ts->input, ABS_MT_POSITION_X,
219						 point[i].coord_x);
220				input_report_abs(ts->input, ABS_MT_POSITION_Y,
221						 point[i].coord_y);
222				input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
223						 point[i].area_major);
224				input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
225						 point[i].area_minor);
226				input_report_abs(ts->input, ABS_MT_ORIENTATION,
227						 point[i].orientation);
228				input_mt_sync(ts->input);
229
230				/* use first finger as source for singletouch */
231				if (fingers == 0)
232					abs = i;
233
234				/* number of touch points could also be queried
235				 * via i2c but would require an additional call
236				 */
237				fingers++;
238			}
239		}
240
241		input_report_key(ts->input, BTN_TOUCH, fingers > 0);
242
243		if (abs > -1) {
244			input_report_abs(ts->input, ABS_X, point[abs].coord_x);
245			input_report_abs(ts->input, ABS_Y, point[abs].coord_y);
246		}
247
248		input_sync(ts->input);
249
250		/* we want to loop only in touch_ind_mode */
251		if (!ts->touch_ind_mode)
252			break;
253
254		wait_event_timeout(ts->wait, ts->stopped,
255				 msecs_to_jiffies(AUO_PIXCIR_PENUP_TIMEOUT_MS));
256	}
257
258	return IRQ_HANDLED;
259}
260
261/*
262 * Set the power mode of the device.
263 * Valid modes are
264 * - AUO_PIXCIR_POWER_ACTIVE
265 * - AUO_PIXCIR_POWER_SLEEP - automatically left on first touch
266 * - AUO_PIXCIR_POWER_DEEP_SLEEP
267 */
268static int auo_pixcir_power_mode(struct auo_pixcir_ts *ts, int mode)
269{
270	struct i2c_client *client = ts->client;
271	int ret;
272
273	ret = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_POWER_MODE);
274	if (ret < 0) {
275		dev_err(&client->dev, "unable to read reg %Xh, %d\n",
276			AUO_PIXCIR_REG_POWER_MODE, ret);
277		return ret;
278	}
279
280	ret &= ~AUO_PIXCIR_POWER_MASK;
281	ret |= mode;
282
283	ret = i2c_smbus_write_byte_data(client, AUO_PIXCIR_REG_POWER_MODE, ret);
284	if (ret) {
285		dev_err(&client->dev, "unable to write reg %Xh, %d\n",
286			AUO_PIXCIR_REG_POWER_MODE, ret);
287		return ret;
288	}
289
290	return 0;
291}
292
293static int auo_pixcir_int_config(struct auo_pixcir_ts *ts, int int_setting)
294{
295	struct i2c_client *client = ts->client;
296	int ret;
297
298	ret = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_INT_SETTING);
299	if (ret < 0) {
300		dev_err(&client->dev, "unable to read reg %Xh, %d\n",
301			AUO_PIXCIR_REG_INT_SETTING, ret);
302		return ret;
303	}
304
305	ret &= ~AUO_PIXCIR_INT_MODE_MASK;
306	ret |= int_setting;
307	ret |= AUO_PIXCIR_INT_POL_HIGH; /* always use high for interrupts */
308
309	ret = i2c_smbus_write_byte_data(client, AUO_PIXCIR_REG_INT_SETTING,
310					ret);
311	if (ret < 0) {
312		dev_err(&client->dev, "unable to write reg %Xh, %d\n",
313			AUO_PIXCIR_REG_INT_SETTING, ret);
314		return ret;
315	}
316
317	ts->touch_ind_mode = int_setting == AUO_PIXCIR_INT_TOUCH_IND;
318
319	return 0;
320}
321
322/* control the generation of interrupts on the device side */
323static int auo_pixcir_int_toggle(struct auo_pixcir_ts *ts, bool enable)
324{
325	struct i2c_client *client = ts->client;
326	int ret;
327
328	ret = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_INT_SETTING);
329	if (ret < 0) {
330		dev_err(&client->dev, "unable to read reg %Xh, %d\n",
331			AUO_PIXCIR_REG_INT_SETTING, ret);
332		return ret;
333	}
334
335	if (enable)
336		ret |= AUO_PIXCIR_INT_ENABLE;
337	else
338		ret &= ~AUO_PIXCIR_INT_ENABLE;
339
340	ret = i2c_smbus_write_byte_data(client, AUO_PIXCIR_REG_INT_SETTING,
341					ret);
342	if (ret < 0) {
343		dev_err(&client->dev, "unable to write reg %Xh, %d\n",
344			AUO_PIXCIR_REG_INT_SETTING, ret);
345		return ret;
346	}
347
348	return 0;
349}
350
351static int auo_pixcir_start(struct auo_pixcir_ts *ts)
352{
353	struct i2c_client *client = ts->client;
354	int ret;
355
356	ret = auo_pixcir_power_mode(ts, AUO_PIXCIR_POWER_ACTIVE);
357	if (ret < 0) {
358		dev_err(&client->dev, "could not set power mode, %d\n",
359			ret);
360		return ret;
361	}
362
363	ts->stopped = false;
364	mb();
365	enable_irq(client->irq);
366
367	ret = auo_pixcir_int_toggle(ts, 1);
368	if (ret < 0) {
369		dev_err(&client->dev, "could not enable interrupt, %d\n",
370			ret);
371		disable_irq(client->irq);
372		return ret;
373	}
374
375	return 0;
376}
377
378static int auo_pixcir_stop(struct auo_pixcir_ts *ts)
379{
380	struct i2c_client *client = ts->client;
381	int ret;
382
383	ret = auo_pixcir_int_toggle(ts, 0);
384	if (ret < 0) {
385		dev_err(&client->dev, "could not disable interrupt, %d\n",
386			ret);
387		return ret;
388	}
389
390	/* disable receiving of interrupts */
391	disable_irq(client->irq);
392	ts->stopped = true;
393	mb();
394	wake_up(&ts->wait);
395
396	return auo_pixcir_power_mode(ts, AUO_PIXCIR_POWER_DEEP_SLEEP);
397}
398
399static int auo_pixcir_input_open(struct input_dev *dev)
400{
401	struct auo_pixcir_ts *ts = input_get_drvdata(dev);
402
403	return auo_pixcir_start(ts);
404}
405
406static void auo_pixcir_input_close(struct input_dev *dev)
407{
408	struct auo_pixcir_ts *ts = input_get_drvdata(dev);
409
410	auo_pixcir_stop(ts);
411}
412
413static int auo_pixcir_suspend(struct device *dev)
414{
415	struct i2c_client *client = to_i2c_client(dev);
416	struct auo_pixcir_ts *ts = i2c_get_clientdata(client);
417	struct input_dev *input = ts->input;
418	int ret = 0;
419
420	mutex_lock(&input->mutex);
421
422	/* when configured as wakeup source, device should always wake system
423	 * therefore start device if necessary
424	 */
425	if (device_may_wakeup(&client->dev)) {
426		/* need to start device if not open, to be wakeup source */
427		if (!input_device_enabled(input)) {
428			ret = auo_pixcir_start(ts);
429			if (ret)
430				goto unlock;
431		}
432
433		enable_irq_wake(client->irq);
434		ret = auo_pixcir_power_mode(ts, AUO_PIXCIR_POWER_SLEEP);
435	} else if (input_device_enabled(input)) {
436		ret = auo_pixcir_stop(ts);
437	}
438
439unlock:
440	mutex_unlock(&input->mutex);
441
442	return ret;
443}
444
445static int auo_pixcir_resume(struct device *dev)
446{
447	struct i2c_client *client = to_i2c_client(dev);
448	struct auo_pixcir_ts *ts = i2c_get_clientdata(client);
449	struct input_dev *input = ts->input;
450	int ret = 0;
451
452	mutex_lock(&input->mutex);
453
454	if (device_may_wakeup(&client->dev)) {
455		disable_irq_wake(client->irq);
456
457		/* need to stop device if it was not open on suspend */
458		if (!input_device_enabled(input)) {
459			ret = auo_pixcir_stop(ts);
460			if (ret)
461				goto unlock;
462		}
463
464		/* device wakes automatically from SLEEP */
465	} else if (input_device_enabled(input)) {
466		ret = auo_pixcir_start(ts);
467	}
468
469unlock:
470	mutex_unlock(&input->mutex);
471
472	return ret;
473}
474
475static DEFINE_SIMPLE_DEV_PM_OPS(auo_pixcir_pm_ops,
476				auo_pixcir_suspend, auo_pixcir_resume);
477
478static void auo_pixcir_reset(void *data)
479{
480	struct auo_pixcir_ts *ts = data;
481
482	gpiod_set_value_cansleep(ts->gpio_rst, 1);
483}
484
485static int auo_pixcir_probe(struct i2c_client *client)
486{
487	struct auo_pixcir_ts *ts;
488	struct input_dev *input_dev;
489	int version;
490	int error;
491
492	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
493	if (!ts)
494		return -ENOMEM;
495
496	input_dev = devm_input_allocate_device(&client->dev);
497	if (!input_dev) {
498		dev_err(&client->dev, "could not allocate input device\n");
499		return -ENOMEM;
500	}
501
502	ts->client = client;
503	ts->input = input_dev;
504	ts->touch_ind_mode = 0;
505	ts->stopped = true;
506	init_waitqueue_head(&ts->wait);
507
508	snprintf(ts->phys, sizeof(ts->phys),
509		 "%s/input0", dev_name(&client->dev));
510
511	if (device_property_read_u32(&client->dev, "x-size", &ts->x_max)) {
512		dev_err(&client->dev, "failed to get x-size property\n");
513		return -EINVAL;
514	}
515
516	if (device_property_read_u32(&client->dev, "y-size", &ts->y_max)) {
517		dev_err(&client->dev, "failed to get y-size property\n");
518		return -EINVAL;
519	}
520
521	input_dev->name = "AUO-Pixcir touchscreen";
522	input_dev->phys = ts->phys;
523	input_dev->id.bustype = BUS_I2C;
524
525	input_dev->open = auo_pixcir_input_open;
526	input_dev->close = auo_pixcir_input_close;
527
528	__set_bit(EV_ABS, input_dev->evbit);
529	__set_bit(EV_KEY, input_dev->evbit);
530
531	__set_bit(BTN_TOUCH, input_dev->keybit);
532
533	/* For single touch */
534	input_set_abs_params(input_dev, ABS_X, 0, ts->x_max, 0, 0);
535	input_set_abs_params(input_dev, ABS_Y, 0, ts->y_max, 0, 0);
536
537	/* For multi touch */
538	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
539	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
540	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
541			     0, AUO_PIXCIR_MAX_AREA, 0, 0);
542	input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
543			     0, AUO_PIXCIR_MAX_AREA, 0, 0);
544	input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
545
546	input_set_drvdata(ts->input, ts);
547
548	ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0, GPIOD_IN);
549	error = PTR_ERR_OR_ZERO(ts->gpio_int);
550	if (error) {
551		dev_err(&client->dev,
552			"request of int gpio failed: %d\n", error);
553		return error;
554	}
555
556	gpiod_set_consumer_name(ts->gpio_int, "auo_pixcir_ts_int");
557
558	/* Take the chip out of reset */
559	ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1,
560					    GPIOD_OUT_LOW);
561	error = PTR_ERR_OR_ZERO(ts->gpio_rst);
562	if (error) {
563		dev_err(&client->dev,
564			"request of reset gpio failed: %d\n", error);
565		return error;
566	}
567
568	gpiod_set_consumer_name(ts->gpio_rst, "auo_pixcir_ts_rst");
569
570	error = devm_add_action_or_reset(&client->dev, auo_pixcir_reset, ts);
571	if (error) {
572		dev_err(&client->dev, "failed to register reset action, %d\n",
573			error);
574		return error;
575	}
576
577	msleep(200);
578
579	version = i2c_smbus_read_byte_data(client, AUO_PIXCIR_REG_VERSION);
580	if (version < 0) {
581		error = version;
582		return error;
583	}
584
585	dev_info(&client->dev, "firmware version 0x%X\n", version);
586
587	/* default to asserting the interrupt when the screen is touched */
588	error = auo_pixcir_int_config(ts, AUO_PIXCIR_INT_TOUCH_IND);
589	if (error)
590		return error;
591
592	error = devm_request_threaded_irq(&client->dev, client->irq,
593					  NULL, auo_pixcir_interrupt,
594					  IRQF_ONESHOT,
595					  input_dev->name, ts);
596	if (error) {
597		dev_err(&client->dev, "irq %d requested failed, %d\n",
598			client->irq, error);
599		return error;
600	}
601
602	/* stop device and put it into deep sleep until it is opened */
603	error = auo_pixcir_stop(ts);
604	if (error)
605		return error;
606
607	error = input_register_device(input_dev);
608	if (error) {
609		dev_err(&client->dev, "could not register input device, %d\n",
610			error);
611		return error;
612	}
613
614	i2c_set_clientdata(client, ts);
615
616	return 0;
617}
618
619static const struct i2c_device_id auo_pixcir_idtable[] = {
620	{ "auo_pixcir_ts", 0 },
621	{ }
622};
623MODULE_DEVICE_TABLE(i2c, auo_pixcir_idtable);
624
625#ifdef CONFIG_OF
626static const struct of_device_id auo_pixcir_ts_dt_idtable[] = {
627	{ .compatible = "auo,auo_pixcir_ts" },
628	{},
629};
630MODULE_DEVICE_TABLE(of, auo_pixcir_ts_dt_idtable);
631#endif
632
633static struct i2c_driver auo_pixcir_driver = {
634	.driver = {
635		.name	= "auo_pixcir_ts",
636		.pm	= pm_sleep_ptr(&auo_pixcir_pm_ops),
637		.of_match_table	= of_match_ptr(auo_pixcir_ts_dt_idtable),
638	},
639	.probe		= auo_pixcir_probe,
640	.id_table	= auo_pixcir_idtable,
641};
642
643module_i2c_driver(auo_pixcir_driver);
644
645MODULE_DESCRIPTION("AUO-PIXCIR touchscreen driver");
646MODULE_LICENSE("GPL v2");
647MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
648