summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/zet6223.c
blob: 19ffcc7b886cd4def34c45275fb4ca59413faf55 (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
/*
 * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/delay.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/module.h>
#include <linux/regulator/consumer.h>
#include <asm/unaligned.h>

#define ZET6223_MAX_FINGERS		16
#define ZET6223_MAX_PKT_SIZE		(3 + 4 * ZET6223_MAX_FINGERS)

#define ZET6223_CMD_INFO		0xB2
#define ZET6223_CMD_INFO_LENGTH		17
#define ZET6223_VALID_PACKET		0x3c

#define ZET6223_POWER_ON_DELAY_MSEC	30

struct zet6223_ts {
	struct i2c_client *client;
	struct input_dev *input;
	struct regulator *vcc;
	struct regulator *vio;
	struct touchscreen_properties prop;
	struct regulator_bulk_data supplies[2];
	u16 max_x;
	u16 max_y;
	u8 fingernum;
};

static int zet6223_start(struct input_dev *dev)
{
	struct zet6223_ts *ts = input_get_drvdata(dev);

	enable_irq(ts->client->irq);

	return 0;
}

static void zet6223_stop(struct input_dev *dev)
{
	struct zet6223_ts *ts = input_get_drvdata(dev);

	disable_irq(ts->client->irq);
}

static irqreturn_t zet6223_irq(int irq, void *dev_id)
{
	struct zet6223_ts *ts = dev_id;
	u16 finger_bits;

	/*
	 * First 3 bytes are an identifier, two bytes of finger data.
	 * X, Y data per finger is 4 bytes.
	 */
	u8 bufsize = 3 + 4 * ts->fingernum;
	u8 buf[ZET6223_MAX_PKT_SIZE];
	int i;
	int ret;
	int error;

	ret = i2c_master_recv(ts->client, buf, bufsize);
	if (ret != bufsize) {
		error = ret < 0 ? ret : -EIO;
		dev_err_ratelimited(&ts->client->dev,
				    "Error reading input data: %d\n", error);
		return IRQ_HANDLED;
	}

	if (buf[0] != ZET6223_VALID_PACKET)
		return IRQ_HANDLED;

	finger_bits = get_unaligned_be16(buf + 1);
	for (i = 0; i < ts->fingernum; i++) {
		if (!(finger_bits & BIT(15 - i)))
			continue;

		input_mt_slot(ts->input, i);
		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
		input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
				((buf[i + 3] >> 4) << 8) + buf[i + 4]);
		input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
				((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
	}

	input_mt_sync_frame(ts->input);
	input_sync(ts->input);

	return IRQ_HANDLED;
}

static void zet6223_power_off(void *_ts)
{
	struct zet6223_ts *ts = _ts;

	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
}

static int zet6223_power_on(struct zet6223_ts *ts)
{
	struct device *dev = &ts->client->dev;
	int error;

	ts->supplies[0].supply = "vio";
	ts->supplies[1].supply = "vcc";

	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
					ts->supplies);
	if (error)
		return error;

	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
	if (error)
		return error;

	msleep(ZET6223_POWER_ON_DELAY_MSEC);

	error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
	if (error) {
		dev_err(dev, "failed to install poweroff action: %d\n", error);
		return error;
	}

	return 0;
}

static int zet6223_query_device(struct zet6223_ts *ts)
{
	u8 buf[ZET6223_CMD_INFO_LENGTH];
	u8 cmd = ZET6223_CMD_INFO;
	int ret;
	int error;

	ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
	if (ret != sizeof(cmd)) {
		error = ret < 0 ? ret : -EIO;
		dev_err(&ts->client->dev,
			"touchpanel info cmd failed: %d\n", error);
		return error;
	}

	ret = i2c_master_recv(ts->client, buf, sizeof(buf));
	if (ret != sizeof(buf)) {
		error = ret < 0 ? ret : -EIO;
		dev_err(&ts->client->dev,
			"failed to retrieve touchpanel info: %d\n", error);
		return error;
	}

	ts->fingernum = buf[15] & 0x7F;
	if (ts->fingernum > ZET6223_MAX_FINGERS) {
		dev_warn(&ts->client->dev,
			 "touchpanel reports %d fingers, limiting to %d\n",
			 ts->fingernum, ZET6223_MAX_FINGERS);
		ts->fingernum = ZET6223_MAX_FINGERS;
	}

	ts->max_x = get_unaligned_le16(&buf[8]);
	ts->max_y = get_unaligned_le16(&buf[10]);

	return 0;
}

static int zet6223_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct zet6223_ts *ts;
	struct input_dev *input;
	int error;

	if (!client->irq) {
		dev_err(dev, "no irq specified\n");
		return -EINVAL;
	}

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

	ts->client = client;

	error = zet6223_power_on(ts);
	if (error)
		return error;

	error = zet6223_query_device(ts);
	if (error)
		return error;

	ts->input = input = devm_input_allocate_device(dev);
	if (!input)
		return -ENOMEM;

	input_set_drvdata(input, ts);

	input->name = client->name;
	input->id.bustype = BUS_I2C;
	input->open = zet6223_start;
	input->close = zet6223_stop;

	input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);

	touchscreen_parse_properties(input, true, &ts->prop);

	error = input_mt_init_slots(input, ts->fingernum,
				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
	if (error)
		return error;

	error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
					  IRQF_ONESHOT, client->name, ts);
	if (error) {
		dev_err(dev, "failed to request irq %d: %d\n",
			client->irq, error);
		return error;
	}

	zet6223_stop(input);

	error = input_register_device(input);
	if (error)
		return error;

	return 0;
}

static const struct of_device_id zet6223_of_match[] = {
	{ .compatible = "zeitec,zet6223" },
	{ }
};
MODULE_DEVICE_TABLE(of, zet6223_of_match);

static const struct i2c_device_id zet6223_id[] = {
	{ "zet6223", 0},
	{ }
};
MODULE_DEVICE_TABLE(i2c, zet6223_id);

static struct i2c_driver zet6223_driver = {
	.driver = {
		.name = "zet6223",
		.of_match_table = zet6223_of_match,
	},
	.probe = zet6223_probe,
	.id_table = zet6223_id
};
module_i2c_driver(zet6223_driver);

MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud