1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Microchip AR1020 and AR1021 driver for I2C
4 *
5 * Author: Christian Gmeiner <christian.gmeiner@gmail.com>
6 */
7
8#include <linux/bitops.h>
9#include <linux/module.h>
10#include <linux/input.h>
11#include <linux/of.h>
12#include <linux/i2c.h>
13#include <linux/irq.h>
14#include <linux/interrupt.h>
15
16#define AR1021_TOUCH_PKG_SIZE	5
17
18#define AR1021_MAX_X	4095
19#define AR1021_MAX_Y	4095
20
21#define AR1021_CMD	0x55
22
23#define AR1021_CMD_ENABLE_TOUCH		0x12
24
25struct ar1021_i2c {
26	struct i2c_client *client;
27	struct input_dev *input;
28	u8 data[AR1021_TOUCH_PKG_SIZE];
29};
30
31static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
32{
33	struct ar1021_i2c *ar1021 = dev_id;
34	struct input_dev *input = ar1021->input;
35	u8 *data = ar1021->data;
36	unsigned int x, y, button;
37	int retval;
38
39	retval = i2c_master_recv(ar1021->client,
40				 ar1021->data, sizeof(ar1021->data));
41	if (retval != sizeof(ar1021->data))
42		goto out;
43
44	/* sync bit set ? */
45	if (!(data[0] & BIT(7)))
46		goto out;
47
48	button = data[0] & BIT(0);
49	x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
50	y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
51
52	input_report_abs(input, ABS_X, x);
53	input_report_abs(input, ABS_Y, y);
54	input_report_key(input, BTN_TOUCH, button);
55	input_sync(input);
56
57out:
58	return IRQ_HANDLED;
59}
60
61static int ar1021_i2c_open(struct input_dev *dev)
62{
63	static const u8 cmd_enable_touch[] = {
64		AR1021_CMD,
65		0x01, /* number of bytes after this */
66		AR1021_CMD_ENABLE_TOUCH
67	};
68	struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
69	struct i2c_client *client = ar1021->client;
70	int error;
71
72	error = i2c_master_send(ar1021->client, cmd_enable_touch,
73				sizeof(cmd_enable_touch));
74	if (error < 0)
75		return error;
76
77	enable_irq(client->irq);
78
79	return 0;
80}
81
82static void ar1021_i2c_close(struct input_dev *dev)
83{
84	struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
85	struct i2c_client *client = ar1021->client;
86
87	disable_irq(client->irq);
88}
89
90static int ar1021_i2c_probe(struct i2c_client *client)
91{
92	struct ar1021_i2c *ar1021;
93	struct input_dev *input;
94	int error;
95
96	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
97		dev_err(&client->dev, "i2c_check_functionality error\n");
98		return -ENXIO;
99	}
100
101	ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
102	if (!ar1021)
103		return -ENOMEM;
104
105	input = devm_input_allocate_device(&client->dev);
106	if (!input)
107		return -ENOMEM;
108
109	ar1021->client = client;
110	ar1021->input = input;
111
112	input->name = "ar1021 I2C Touchscreen";
113	input->id.bustype = BUS_I2C;
114	input->dev.parent = &client->dev;
115	input->open = ar1021_i2c_open;
116	input->close = ar1021_i2c_close;
117
118	__set_bit(INPUT_PROP_DIRECT, input->propbit);
119	input_set_capability(input, EV_KEY, BTN_TOUCH);
120	input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
121	input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
122
123	input_set_drvdata(input, ar1021);
124
125	error = devm_request_threaded_irq(&client->dev, client->irq,
126					  NULL, ar1021_i2c_irq,
127					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
128					  "ar1021_i2c", ar1021);
129	if (error) {
130		dev_err(&client->dev,
131			"Failed to enable IRQ, error: %d\n", error);
132		return error;
133	}
134
135	error = input_register_device(ar1021->input);
136	if (error) {
137		dev_err(&client->dev,
138			"Failed to register input device, error: %d\n", error);
139		return error;
140	}
141
142	return 0;
143}
144
145static int ar1021_i2c_suspend(struct device *dev)
146{
147	struct i2c_client *client = to_i2c_client(dev);
148
149	disable_irq(client->irq);
150
151	return 0;
152}
153
154static int ar1021_i2c_resume(struct device *dev)
155{
156	struct i2c_client *client = to_i2c_client(dev);
157
158	enable_irq(client->irq);
159
160	return 0;
161}
162
163static DEFINE_SIMPLE_DEV_PM_OPS(ar1021_i2c_pm,
164				ar1021_i2c_suspend, ar1021_i2c_resume);
165
166static const struct i2c_device_id ar1021_i2c_id[] = {
167	{ "ar1021", 0 },
168	{ },
169};
170MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
171
172static const struct of_device_id ar1021_i2c_of_match[] = {
173	{ .compatible = "microchip,ar1021-i2c", },
174	{ }
175};
176MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
177
178static struct i2c_driver ar1021_i2c_driver = {
179	.driver	= {
180		.name	= "ar1021_i2c",
181		.pm	= pm_sleep_ptr(&ar1021_i2c_pm),
182		.of_match_table = ar1021_i2c_of_match,
183	},
184
185	.probe		= ar1021_i2c_probe,
186	.id_table	= ar1021_i2c_id,
187};
188module_i2c_driver(ar1021_i2c_driver);
189
190MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
191MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
192MODULE_LICENSE("GPL");
193