gpio_mouse.c
/*
* Driver for simulating a mouse on GPIO lines.
*
* Copyright (C) 2007 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/input-polldev.h>
#include <linux/gpio_mouse.h>
#include <asm/gpio.h>
/*
* Timer function which is run every scan_ms ms when the device is opened.
* The dev input varaible is set to the the input_dev pointer.
*/
static void gpio_mouse_scan(struct input_polled_dev *dev)
{
struct gpio_mouse_platform_data *gpio = dev->private;
struct input_dev *input = dev->input;
int x, y;
if (gpio->bleft >= 0)
input_report_key(input, BTN_LEFT,
gpio_get_value(gpio->bleft) ^ gpio->polarity);
if (gpio->bmiddle >= 0)
input_report_key(input, BTN_MIDDLE,
gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
if (gpio->bright >= 0)
input_report_key(input, BTN_RIGHT,
gpio_get_value(gpio->bright) ^ gpio->polarity);
x = (gpio_get_value(gpio->right) ^ gpio->polarity)
- (gpio_get_value(gpio->left) ^ gpio->polarity);
y = (gpio_get_value(gpio->down) ^ gpio->polarity)
- (gpio_get_value(gpio->up) ^ gpio->polarity);
input_report_rel(input, REL_X, x);
input_report_rel(input, REL_Y, y);
input_sync(input);
}
static int __init gpio_mouse_probe(struct platform_device *pdev)
{
struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
struct input_polled_dev *input_poll;
struct input_dev *input;
int pin, i;
int error;
if (!pdata) {
dev_err(&pdev->dev, "no platform data\n");
error = -ENXIO;
goto out;
}
if (pdata->scan_ms < 0) {
dev_err(&pdev->dev, "invalid scan time\n");
error = -EINVAL;
goto out;
}
for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
pin = pdata->pins[i];
if (pin < 0) {
if (i <= GPIO_MOUSE_PIN_RIGHT) {
/* Mouse direction is required. */
dev_err(&pdev->dev,
"missing GPIO for directions\n");
error = -EINVAL;
goto out_free_gpios;
}
if (i == GPIO_MOUSE_PIN_BLEFT)
dev_dbg(&pdev->dev, "no left button defined\n");
} else {
error = gpio_request(pin, "gpio_mouse");
if (error) {
dev_err(&pdev->dev, "fail %d pin (%d idx)\n",
pin, i);
goto out_free_gpios;
}
gpio_direction_input(pin);
}
}
input_poll = input_allocate_polled_device();
if (!input_poll) {
dev_err(&pdev->dev, "not enough memory for input device\n");
error = -ENOMEM;
goto out_free_gpios;
}
platform_set_drvdata(pdev, input_poll);
/* set input-polldev handlers */
input_poll->private = pdata;
input_poll->poll = gpio_mouse_scan;
input_poll->poll_interval = pdata->scan_ms;
input = input_poll->input;
input->name = pdev->name;
input->id.bustype = BUS_HOST;
input->dev.parent = &pdev->dev;
input_set_capability(input, EV_REL, REL_X);
input_set_capability(input, EV_REL, REL_Y);
if (pdata->bleft >= 0)
input_set_capability(input, EV_KEY, BTN_LEFT);
if (pdata->bmiddle >= 0)
input_set_capability(input, EV_KEY, BTN_MIDDLE);
if (pdata->bright >= 0)
input_set_capability(input, EV_KEY, BTN_RIGHT);
error = input_register_polled_device(input_poll);
if (error) {
dev_err(&pdev->dev, "could not register input device\n");
goto out_free_polldev;
}
dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
pdata->scan_ms,
pdata->bleft < 0 ? "" : "left ",
pdata->bmiddle < 0 ? "" : "middle ",
pdata->bright < 0 ? "" : "right");
return 0;
out_free_polldev:
input_free_polled_device(input_poll);
platform_set_drvdata(pdev, NULL);
out_free_gpios:
while (--i >= 0) {
pin = pdata->pins[i];
if (pin)
gpio_free(pin);
}
out:
return error;
}
static int __devexit gpio_mouse_remove(struct platform_device *pdev)
{
struct input_polled_dev *input = platform_get_drvdata(pdev);
struct gpio_mouse_platform_data *pdata = input->private;
int pin, i;
input_unregister_polled_device(input);
input_free_polled_device(input);
for (i = 0; i < GPIO_MOUSE_PIN_MAX; i++) {
pin = pdata->pins[i];
if (pin >= 0)
gpio_free(pin);
}
platform_set_drvdata(pdev, NULL);
return 0;
}
struct platform_driver gpio_mouse_device_driver = {
.remove = __devexit_p(gpio_mouse_remove),
.driver = {
.name = "gpio_mouse",
}
};
static int __init gpio_mouse_init(void)
{
return platform_driver_probe(&gpio_mouse_device_driver,
gpio_mouse_probe);
}
module_init(gpio_mouse_init);
static void __exit gpio_mouse_exit(void)
{
platform_driver_unregister(&gpio_mouse_device_driver);
}
module_exit(gpio_mouse_exit);
MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
MODULE_DESCRIPTION("GPIO mouse driver");
MODULE_LICENSE("GPL");