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			    const struct i2c_device_id *id)
 92{
 93	struct ar1021_i2c *ar1021;
 94	struct input_dev *input;
 95	int error;
 96
 97	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 98		dev_err(&client->dev, "i2c_check_functionality error\n");
 99		return -ENXIO;
100	}
101
102	ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
103	if (!ar1021)
104		return -ENOMEM;
105
106	input = devm_input_allocate_device(&client->dev);
107	if (!input)
108		return -ENOMEM;
109
110	ar1021->client = client;
111	ar1021->input = input;
112
113	input->name = "ar1021 I2C Touchscreen";
114	input->id.bustype = BUS_I2C;
115	input->dev.parent = &client->dev;
116	input->open = ar1021_i2c_open;
117	input->close = ar1021_i2c_close;
118
119	__set_bit(INPUT_PROP_DIRECT, input->propbit);
120	input_set_capability(input, EV_KEY, BTN_TOUCH);
121	input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
122	input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
123
124	input_set_drvdata(input, ar1021);
125
126	error = devm_request_threaded_irq(&client->dev, client->irq,
127					  NULL, ar1021_i2c_irq,
128					  IRQF_ONESHOT,
129					  "ar1021_i2c", ar1021);
130	if (error) {
131		dev_err(&client->dev,
132			"Failed to enable IRQ, error: %d\n", error);
133		return error;
134	}
135
136	/* Disable the IRQ, we'll enable it in ar1021_i2c_open() */
137	disable_irq(client->irq);
138
139	error = input_register_device(ar1021->input);
140	if (error) {
141		dev_err(&client->dev,
142			"Failed to register input device, error: %d\n", error);
143		return error;
144	}
145
146	return 0;
147}
148
149static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
150{
151	struct i2c_client *client = to_i2c_client(dev);
152
153	disable_irq(client->irq);
154
155	return 0;
156}
157
158static int __maybe_unused ar1021_i2c_resume(struct device *dev)
159{
160	struct i2c_client *client = to_i2c_client(dev);
161
162	enable_irq(client->irq);
163
164	return 0;
165}
166
167static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
168
169static const struct i2c_device_id ar1021_i2c_id[] = {
170	{ "ar1021", 0 },
171	{ },
172};
173MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
174
175static const struct of_device_id ar1021_i2c_of_match[] = {
176	{ .compatible = "microchip,ar1021-i2c", },
177	{ }
178};
179MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
180
181static struct i2c_driver ar1021_i2c_driver = {
182	.driver	= {
183		.name	= "ar1021_i2c",
184		.pm	= &ar1021_i2c_pm,
185		.of_match_table = ar1021_i2c_of_match,
186	},
187
188	.probe		= ar1021_i2c_probe,
189	.id_table	= ar1021_i2c_id,
190};
191module_i2c_driver(ar1021_i2c_driver);
192
193MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
194MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
195MODULE_LICENSE("GPL");