summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/msg2638.c
blob: 4c0816b09d332ef29b49c143af54af95a8a3f8a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for MStar msg2638 touchscreens
 *
 * Copyright (c) 2021 Vincent Knecht <vincent.knecht@mailoo.org>
 *
 * Checksum and IRQ handler based on mstar_drv_common.c and
 * mstar_drv_mutual_fw_control.c
 * Copyright (c) 2006-2012 MStar Semiconductor, Inc.
 *
 * Driver structure based on zinitix.c by Michael Srba <Michael.Srba@seznam.cz>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

#define MODE_DATA_RAW			0x5A

#define MSG2138_MAX_FINGERS		2
#define MSG2638_MAX_FINGERS		5

#define MAX_BUTTONS			4

#define CHIP_ON_DELAY_MS		15
#define FIRMWARE_ON_DELAY_MS		50
#define RESET_DELAY_MIN_US		10000
#define RESET_DELAY_MAX_US		11000

struct msg_chip_data {
	irq_handler_t irq_handler;
	unsigned int max_fingers;
};

struct msg2138_packet {
	u8	xy_hi; /* higher bits of x and y coordinates */
	u8	x_low;
	u8	y_low;
};

struct msg2138_touch_event {
	u8	magic;
	struct	msg2138_packet pkt[MSG2138_MAX_FINGERS];
	u8	checksum;
};

struct msg2638_packet {
	u8	xy_hi; /* higher bits of x and y coordinates */
	u8	x_low;
	u8	y_low;
	u8	pressure;
};

struct msg2638_touch_event {
	u8	mode;
	struct	msg2638_packet pkt[MSG2638_MAX_FINGERS];
	u8	proximity;
	u8	checksum;
};

struct msg2638_ts_data {
	struct i2c_client *client;
	struct input_dev *input_dev;
	struct touchscreen_properties prop;
	struct regulator_bulk_data supplies[2];
	struct gpio_desc *reset_gpiod;
	int max_fingers;
	u32 keycodes[MAX_BUTTONS];
	int num_keycodes;
};

static u8 msg2638_checksum(u8 *data, u32 length)
{
	s32 sum = 0;
	u32 i;

	for (i = 0; i < length; i++)
		sum += data[i];

	return (u8)((-sum) & 0xFF);
}

static void msg2138_report_keys(struct msg2638_ts_data *msg2638, u8 keys)
{
	int i;

	/* keys can be 0x00 or 0xff when all keys have been released */
	if (keys == 0xff)
		keys = 0;

	for (i = 0; i < msg2638->num_keycodes; ++i)
		input_report_key(msg2638->input_dev, msg2638->keycodes[i],
				 keys & BIT(i));
}

static irqreturn_t msg2138_ts_irq_handler(int irq, void *msg2638_handler)
{
	struct msg2638_ts_data *msg2638 = msg2638_handler;
	struct i2c_client *client = msg2638->client;
	struct input_dev *input = msg2638->input_dev;
	struct msg2138_touch_event touch_event;
	u32 len = sizeof(touch_event);
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags	= I2C_M_RD,
			.len	= sizeof(touch_event),
			.buf	= (u8 *)&touch_event,
		},
	};
	struct msg2138_packet *p0, *p1;
	u16 x, y, delta_x, delta_y;
	int ret;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(&client->dev,
			"Failed I2C transfer in irq handler: %d\n",
			ret < 0 ? ret : -EIO);
		goto out;
	}

	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
						touch_event.checksum) {
		dev_err(&client->dev, "Failed checksum!\n");
		goto out;
	}

	p0 = &touch_event.pkt[0];
	p1 = &touch_event.pkt[1];

	/* Ignore non-pressed finger data, but check for key code */
	if (p0->xy_hi == 0xFF && p0->x_low == 0xFF && p0->y_low == 0xFF) {
		if (p1->xy_hi == 0xFF && p1->y_low == 0xFF)
			msg2138_report_keys(msg2638, p1->x_low);
		goto report;
	}

	x = ((p0->xy_hi & 0xF0) << 4) | p0->x_low;
	y = ((p0->xy_hi & 0x0F) << 8) | p0->y_low;

	input_mt_slot(input, 0);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

	/* Ignore non-pressed finger data */
	if (p1->xy_hi == 0xFF && p1->x_low == 0xFF && p1->y_low == 0xFF)
		goto report;

	/* Second finger is reported as a delta position */
	delta_x = ((p1->xy_hi & 0xF0) << 4) | p1->x_low;
	delta_y = ((p1->xy_hi & 0x0F) << 8) | p1->y_low;

	/* Ignore second finger if both deltas equal 0 */
	if (delta_x == 0 && delta_y == 0)
		goto report;

	x += delta_x;
	y += delta_y;

	input_mt_slot(input, 1);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
	touchscreen_report_pos(input, &msg2638->prop, x, y, true);

report:
	input_mt_sync_frame(msg2638->input_dev);
	input_sync(msg2638->input_dev);

out:
	return IRQ_HANDLED;
}

static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)
{
	struct msg2638_ts_data *msg2638 = msg2638_handler;
	struct i2c_client *client = msg2638->client;
	struct input_dev *input = msg2638->input_dev;
	struct msg2638_touch_event touch_event;
	u32 len = sizeof(touch_event);
	struct i2c_msg msg[] = {
		{
			.addr	= client->addr,
			.flags	= I2C_M_RD,
			.len	= sizeof(touch_event),
			.buf	= (u8 *)&touch_event,
		},
	};
	struct msg2638_packet *p;
	u16 x, y;
	int ret;
	int i;

	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	if (ret != ARRAY_SIZE(msg)) {
		dev_err(&client->dev,
			"Failed I2C transfer in irq handler: %d\n",
			ret < 0 ? ret : -EIO);
		goto out;
	}

	if (touch_event.mode != MODE_DATA_RAW)
		goto out;

	if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
						touch_event.checksum) {
		dev_err(&client->dev, "Failed checksum!\n");
		goto out;
	}

	for (i = 0; i < msg2638->max_fingers; i++) {
		p = &touch_event.pkt[i];

		/* Ignore non-pressed finger data */
		if (p->xy_hi == 0xFF && p->x_low == 0xFF && p->y_low == 0xFF)
			continue;

		x = (((p->xy_hi & 0xF0) << 4) | p->x_low);
		y = (((p->xy_hi & 0x0F) << 8) | p->y_low);

		input_mt_slot(input, i);
		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
		touchscreen_report_pos(input, &msg2638->prop, x, y, true);
	}

	input_mt_sync_frame(msg2638->input_dev);
	input_sync(msg2638->input_dev);

out:
	return IRQ_HANDLED;
}

static void msg2638_reset(struct msg2638_ts_data *msg2638)
{
	gpiod_set_value_cansleep(msg2638->reset_gpiod, 1);
	usleep_range(RESET_DELAY_MIN_US, RESET_DELAY_MAX_US);
	gpiod_set_value_cansleep(msg2638->reset_gpiod, 0);
	msleep(FIRMWARE_ON_DELAY_MS);
}

static int msg2638_start(struct msg2638_ts_data *msg2638)
{
	int error;

	error = regulator_bulk_enable(ARRAY_SIZE(msg2638->supplies),
				      msg2638->supplies);
	if (error) {
		dev_err(&msg2638->client->dev,
			"Failed to enable regulators: %d\n", error);
		return error;
	}

	msleep(CHIP_ON_DELAY_MS);

	msg2638_reset(msg2638);

	enable_irq(msg2638->client->irq);

	return 0;
}

static int msg2638_stop(struct msg2638_ts_data *msg2638)
{
	int error;

	disable_irq(msg2638->client->irq);

	error = regulator_bulk_disable(ARRAY_SIZE(msg2638->supplies),
				       msg2638->supplies);
	if (error) {
		dev_err(&msg2638->client->dev,
			"Failed to disable regulators: %d\n", error);
		return error;
	}

	return 0;
}

static int msg2638_input_open(struct input_dev *dev)
{
	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

	return msg2638_start(msg2638);
}

static void msg2638_input_close(struct input_dev *dev)
{
	struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);

	msg2638_stop(msg2638);
}

static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
{
	struct device *dev = &msg2638->client->dev;
	struct input_dev *input_dev;
	int error;
	int i;

	input_dev = devm_input_allocate_device(dev);
	if (!input_dev) {
		dev_err(dev, "Failed to allocate input device.\n");
		return -ENOMEM;
	}

	input_set_drvdata(input_dev, msg2638);
	msg2638->input_dev = input_dev;

	input_dev->name = "MStar TouchScreen";
	input_dev->phys = "input/ts";
	input_dev->id.bustype = BUS_I2C;
	input_dev->open = msg2638_input_open;
	input_dev->close = msg2638_input_close;

	if (msg2638->num_keycodes) {
		input_dev->keycode = msg2638->keycodes;
		input_dev->keycodemax = msg2638->num_keycodes;
		input_dev->keycodesize = sizeof(msg2638->keycodes[0]);
		for (i = 0; i < msg2638->num_keycodes; i++)
			input_set_capability(input_dev,
					     EV_KEY, msg2638->keycodes[i]);
	}

	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
	input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);

	touchscreen_parse_properties(input_dev, true, &msg2638->prop);
	if (!msg2638->prop.max_x || !msg2638->prop.max_y) {
		dev_err(dev, "touchscreen-size-x and/or touchscreen-size-y not set in properties\n");
		return -EINVAL;
	}

	error = input_mt_init_slots(input_dev, msg2638->max_fingers,
				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
	if (error) {
		dev_err(dev, "Failed to initialize MT slots: %d\n", error);
		return error;
	}

	error = input_register_device(input_dev);
	if (error) {
		dev_err(dev, "Failed to register input device: %d\n", error);
		return error;
	}

	return 0;
}

static int msg2638_ts_probe(struct i2c_client *client)
{
	const struct msg_chip_data *chip_data;
	struct device *dev = &client->dev;
	struct msg2638_ts_data *msg2638;
	int error;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(dev, "Failed to assert adapter's support for plain I2C.\n");
		return -ENXIO;
	}

	msg2638 = devm_kzalloc(dev, sizeof(*msg2638), GFP_KERNEL);
	if (!msg2638)
		return -ENOMEM;

	msg2638->client = client;
	i2c_set_clientdata(client, msg2638);

	chip_data = device_get_match_data(&client->dev);
	if (!chip_data || !chip_data->max_fingers) {
		dev_err(dev, "Invalid or missing chip data\n");
		return -EINVAL;
	}

	msg2638->max_fingers = chip_data->max_fingers;

	msg2638->supplies[0].supply = "vdd";
	msg2638->supplies[1].supply = "vddio";
	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(msg2638->supplies),
					msg2638->supplies);
	if (error) {
		dev_err(dev, "Failed to get regulators: %d\n", error);
		return error;
	}

	msg2638->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(msg2638->reset_gpiod)) {
		error = PTR_ERR(msg2638->reset_gpiod);
		dev_err(dev, "Failed to request reset GPIO: %d\n", error);
		return error;
	}

	msg2638->num_keycodes = device_property_count_u32(dev,
							  "linux,keycodes");
	if (msg2638->num_keycodes == -EINVAL) {
		msg2638->num_keycodes = 0;
	} else if (msg2638->num_keycodes < 0) {
		dev_err(dev, "Unable to parse linux,keycodes property: %d\n",
			msg2638->num_keycodes);
		return msg2638->num_keycodes;
	} else if (msg2638->num_keycodes > ARRAY_SIZE(msg2638->keycodes)) {
		dev_warn(dev, "Found %d linux,keycodes but max is %zd, ignoring the rest\n",
			 msg2638->num_keycodes, ARRAY_SIZE(msg2638->keycodes));
		msg2638->num_keycodes = ARRAY_SIZE(msg2638->keycodes);
	}

	if (msg2638->num_keycodes > 0) {
		error = device_property_read_u32_array(dev, "linux,keycodes",
						       msg2638->keycodes,
						       msg2638->num_keycodes);
		if (error) {
			dev_err(dev, "Unable to read linux,keycodes values: %d\n",
				error);
			return error;
		}
	}

	error = devm_request_threaded_irq(dev, client->irq,
					  NULL, chip_data->irq_handler,
					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
					  client->name, msg2638);
	if (error) {
		dev_err(dev, "Failed to request IRQ: %d\n", error);
		return error;
	}

	error = msg2638_init_input_dev(msg2638);
	if (error) {
		dev_err(dev, "Failed to initialize input device: %d\n", error);
		return error;
	}

	return 0;
}

static int __maybe_unused msg2638_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);

	mutex_lock(&msg2638->input_dev->mutex);

	if (input_device_enabled(msg2638->input_dev))
		msg2638_stop(msg2638);

	mutex_unlock(&msg2638->input_dev->mutex);

	return 0;
}

static int __maybe_unused msg2638_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
	int ret = 0;

	mutex_lock(&msg2638->input_dev->mutex);

	if (input_device_enabled(msg2638->input_dev))
		ret = msg2638_start(msg2638);

	mutex_unlock(&msg2638->input_dev->mutex);

	return ret;
}

static SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);

static const struct msg_chip_data msg2138_data = {
	.irq_handler = msg2138_ts_irq_handler,
	.max_fingers = MSG2138_MAX_FINGERS,
};

static const struct msg_chip_data msg2638_data = {
	.irq_handler = msg2638_ts_irq_handler,
	.max_fingers = MSG2638_MAX_FINGERS,
};

static const struct of_device_id msg2638_of_match[] = {
	{ .compatible = "mstar,msg2138", .data = &msg2138_data },
	{ .compatible = "mstar,msg2638", .data = &msg2638_data },
	{ }
};
MODULE_DEVICE_TABLE(of, msg2638_of_match);

static struct i2c_driver msg2638_ts_driver = {
	.probe_new = msg2638_ts_probe,
	.driver = {
		.name = "MStar-TS",
		.pm = &msg2638_pm_ops,
		.of_match_table = msg2638_of_match,
	},
};
module_i2c_driver(msg2638_ts_driver);

MODULE_AUTHOR("Vincent Knecht <vincent.knecht@mailoo.org>");
MODULE_DESCRIPTION("MStar MSG2638 touchscreen driver");
MODULE_LICENSE("GPL v2");