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/*
* Microchip AR1020 and AR1021 driver for I2C
*
* Author: Christian Gmeiner <christian.gmeiner@gmail.com>
*
* License: GPLv2 as published by the FSF.
*/
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/of.h>
#include <linux/i2c.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#define AR1021_TOCUH_PKG_SIZE 5
#define AR1021_MAX_X 4095
#define AR1021_MAX_Y 4095
#define AR1021_CMD 0x55
#define AR1021_CMD_ENABLE_TOUCH 0x12
struct ar1021_i2c {
struct i2c_client *client;
struct input_dev *input;
u8 data[AR1021_TOCUH_PKG_SIZE];
};
static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
{
struct ar1021_i2c *ar1021 = dev_id;
struct input_dev *input = ar1021->input;
u8 *data = ar1021->data;
unsigned int x, y, button;
int retval;
retval = i2c_master_recv(ar1021->client,
ar1021->data, sizeof(ar1021->data));
if (retval != sizeof(ar1021->data))
goto out;
/* sync bit set ? */
if (!(data[0] & BIT(7)))
goto out;
button = data[0] & BIT(0);
x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
input_report_abs(input, ABS_X, x);
input_report_abs(input, ABS_Y, y);
input_report_key(input, BTN_TOUCH, button);
input_sync(input);
out:
return IRQ_HANDLED;
}
static int ar1021_i2c_open(struct input_dev *dev)
{
static const u8 cmd_enable_touch[] = {
AR1021_CMD,
0x01, /* number of bytes after this */
AR1021_CMD_ENABLE_TOUCH
};
struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
struct i2c_client *client = ar1021->client;
int error;
error = i2c_master_send(ar1021->client, cmd_enable_touch,
sizeof(cmd_enable_touch));
if (error < 0)
return error;
enable_irq(client->irq);
return 0;
}
static void ar1021_i2c_close(struct input_dev *dev)
{
struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
struct i2c_client *client = ar1021->client;
disable_irq(client->irq);
}
static int ar1021_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ar1021_i2c *ar1021;
struct input_dev *input;
int error;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev, "i2c_check_functionality error\n");
return -ENXIO;
}
ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
if (!ar1021)
return -ENOMEM;
input = devm_input_allocate_device(&client->dev);
if (!input)
return -ENOMEM;
ar1021->client = client;
ar1021->input = input;
input->name = "ar1021 I2C Touchscreen";
input->id.bustype = BUS_I2C;
input->dev.parent = &client->dev;
input->open = ar1021_i2c_open;
input->close = ar1021_i2c_close;
input_set_capability(input, EV_KEY, BTN_TOUCH);
input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
input_set_drvdata(input, ar1021);
error = devm_request_threaded_irq(&client->dev, client->irq,
NULL, ar1021_i2c_irq,
IRQF_ONESHOT,
"ar1021_i2c", ar1021);
if (error) {
dev_err(&client->dev,
"Failed to enable IRQ, error: %d\n", error);
return error;
}
/* Disable the IRQ, we'll enable it in ar1021_i2c_open() */
disable_irq(client->irq);
error = input_register_device(ar1021->input);
if (error) {
dev_err(&client->dev,
"Failed to register input device, error: %d\n", error);
return error;
}
return 0;
}
static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
disable_irq(client->irq);
return 0;
}
static int __maybe_unused ar1021_i2c_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
enable_irq(client->irq);
return 0;
}
static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
static const struct i2c_device_id ar1021_i2c_id[] = {
{ "ar1021", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
static const struct of_device_id ar1021_i2c_of_match[] = {
{ .compatible = "microchip,ar1021-i2c", },
{ }
};
MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
static struct i2c_driver ar1021_i2c_driver = {
.driver = {
.name = "ar1021_i2c",
.pm = &ar1021_i2c_pm,
.of_match_table = ar1021_i2c_of_match,
},
.probe = ar1021_i2c_probe,
.id_table = ar1021_i2c_id,
};
module_i2c_driver(ar1021_i2c_driver);
MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
MODULE_LICENSE("GPL");
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