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8a038b83e0
The MSB for the first byte of touch data transmission is always 1. Make it a little more obvious we're testing this bit by using BIT(7). Signed-off-by: Martin Kepplinger <martink@posteo.de> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
196 lines
4.3 KiB
C
196 lines
4.3 KiB
C
/*
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* Microchip AR1020 and AR1021 driver for I2C
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*
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* Author: Christian Gmeiner <christian.gmeiner@gmail.com>
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*
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* License: GPLv2 as published by the FSF.
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*/
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#include <linux/bitops.h>
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/of.h>
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#include <linux/i2c.h>
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#include <linux/irq.h>
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#include <linux/interrupt.h>
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#define AR1021_TOCUH_PKG_SIZE 5
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#define AR1021_MAX_X 4095
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#define AR1021_MAX_Y 4095
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#define AR1021_CMD 0x55
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#define AR1021_CMD_ENABLE_TOUCH 0x12
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struct ar1021_i2c {
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struct i2c_client *client;
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struct input_dev *input;
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u8 data[AR1021_TOCUH_PKG_SIZE];
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};
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static irqreturn_t ar1021_i2c_irq(int irq, void *dev_id)
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{
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struct ar1021_i2c *ar1021 = dev_id;
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struct input_dev *input = ar1021->input;
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u8 *data = ar1021->data;
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unsigned int x, y, button;
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int retval;
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retval = i2c_master_recv(ar1021->client,
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ar1021->data, sizeof(ar1021->data));
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if (retval != sizeof(ar1021->data))
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goto out;
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/* sync bit set ? */
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if (!(data[0] & BIT(7)))
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goto out;
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button = data[0] & BIT(0);
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x = ((data[2] & 0x1f) << 7) | (data[1] & 0x7f);
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y = ((data[4] & 0x1f) << 7) | (data[3] & 0x7f);
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input_report_abs(input, ABS_X, x);
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input_report_abs(input, ABS_Y, y);
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input_report_key(input, BTN_TOUCH, button);
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input_sync(input);
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out:
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return IRQ_HANDLED;
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}
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static int ar1021_i2c_open(struct input_dev *dev)
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{
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static const u8 cmd_enable_touch[] = {
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AR1021_CMD,
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0x01, /* number of bytes after this */
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AR1021_CMD_ENABLE_TOUCH
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};
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struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
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struct i2c_client *client = ar1021->client;
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int error;
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error = i2c_master_send(ar1021->client, cmd_enable_touch,
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sizeof(cmd_enable_touch));
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if (error < 0)
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return error;
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enable_irq(client->irq);
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return 0;
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}
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static void ar1021_i2c_close(struct input_dev *dev)
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{
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struct ar1021_i2c *ar1021 = input_get_drvdata(dev);
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struct i2c_client *client = ar1021->client;
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disable_irq(client->irq);
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}
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static int ar1021_i2c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ar1021_i2c *ar1021;
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struct input_dev *input;
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int error;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev, "i2c_check_functionality error\n");
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return -ENXIO;
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}
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ar1021 = devm_kzalloc(&client->dev, sizeof(*ar1021), GFP_KERNEL);
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if (!ar1021)
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return -ENOMEM;
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input = devm_input_allocate_device(&client->dev);
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if (!input)
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return -ENOMEM;
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ar1021->client = client;
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ar1021->input = input;
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input->name = "ar1021 I2C Touchscreen";
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input->id.bustype = BUS_I2C;
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input->dev.parent = &client->dev;
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input->open = ar1021_i2c_open;
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input->close = ar1021_i2c_close;
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input_set_capability(input, EV_KEY, BTN_TOUCH);
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input_set_abs_params(input, ABS_X, 0, AR1021_MAX_X, 0, 0);
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input_set_abs_params(input, ABS_Y, 0, AR1021_MAX_Y, 0, 0);
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input_set_drvdata(input, ar1021);
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error = devm_request_threaded_irq(&client->dev, client->irq,
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NULL, ar1021_i2c_irq,
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IRQF_ONESHOT,
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"ar1021_i2c", ar1021);
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if (error) {
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dev_err(&client->dev,
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"Failed to enable IRQ, error: %d\n", error);
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return error;
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}
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/* Disable the IRQ, we'll enable it in ar1021_i2c_open() */
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disable_irq(client->irq);
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error = input_register_device(ar1021->input);
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if (error) {
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dev_err(&client->dev,
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"Failed to register input device, error: %d\n", error);
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return error;
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}
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return 0;
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}
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static int __maybe_unused ar1021_i2c_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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disable_irq(client->irq);
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return 0;
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}
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static int __maybe_unused ar1021_i2c_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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enable_irq(client->irq);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(ar1021_i2c_pm, ar1021_i2c_suspend, ar1021_i2c_resume);
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static const struct i2c_device_id ar1021_i2c_id[] = {
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{ "ar1021", 0 },
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{ },
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};
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MODULE_DEVICE_TABLE(i2c, ar1021_i2c_id);
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static const struct of_device_id ar1021_i2c_of_match[] = {
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{ .compatible = "microchip,ar1021-i2c", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ar1021_i2c_of_match);
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static struct i2c_driver ar1021_i2c_driver = {
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.driver = {
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.name = "ar1021_i2c",
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.pm = &ar1021_i2c_pm,
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.of_match_table = ar1021_i2c_of_match,
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},
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.probe = ar1021_i2c_probe,
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.id_table = ar1021_i2c_id,
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};
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module_i2c_driver(ar1021_i2c_driver);
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MODULE_AUTHOR("Christian Gmeiner <christian.gmeiner@gmail.com>");
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MODULE_DESCRIPTION("Microchip AR1020 and AR1021 I2C Driver");
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MODULE_LICENSE("GPL");
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