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// SPDX-License-Identifier: GPL-2.0-only
/*
* Support for the S1 button on Routerboard 532
*
* Copyright (C) 2009 Phil Sutter <n0-1@freewrt.org>
*/
#include <linux/input-polldev.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <asm/mach-rc32434/gpio.h>
#include <asm/mach-rc32434/rb.h>
#define DRV_NAME "rb532-button"
#define RB532_BTN_RATE 100 /* msec */
#define RB532_BTN_KSYM BTN_0
/* The S1 button state is provided by GPIO pin 1. But as this
* pin is also used for uart input as alternate function, the
* operational modes must be switched first:
* 1) disable uart using set_latch_u5()
* 2) turn off alternate function implicitly through
* gpio_direction_input()
* 3) read the GPIO's current value
* 4) undo step 2 by enabling alternate function (in this
* mode the GPIO direction is fixed, so no change needed)
* 5) turn on uart again
* The GPIO value occurs to be inverted, so pin high means
* button is not pressed.
*/
static bool rb532_button_pressed(void)
{
int val;
set_latch_u5(0, LO_FOFF);
gpio_direction_input(GPIO_BTN_S1);
val = gpio_get_value(GPIO_BTN_S1);
rb532_gpio_set_func(GPIO_BTN_S1);
set_latch_u5(LO_FOFF, 0);
return !val;
}
static void rb532_button_poll(struct input_polled_dev *poll_dev)
{
input_report_key(poll_dev->input, RB532_BTN_KSYM,
rb532_button_pressed());
input_sync(poll_dev->input);
}
static int rb532_button_probe(struct platform_device *pdev)
{
struct input_polled_dev *poll_dev;
int error;
poll_dev = input_allocate_polled_device();
if (!poll_dev)
return -ENOMEM;
poll_dev->poll = rb532_button_poll;
poll_dev->poll_interval = RB532_BTN_RATE;
poll_dev->input->name = "rb532 button";
poll_dev->input->phys = "rb532/button0";
poll_dev->input->id.bustype = BUS_HOST;
poll_dev->input->dev.parent = &pdev->dev;
dev_set_drvdata(&pdev->dev, poll_dev);
input_set_capability(poll_dev->input, EV_KEY, RB532_BTN_KSYM);
error = input_register_polled_device(poll_dev);
if (error) {
input_free_polled_device(poll_dev);
return error;
}
return 0;
}
static int rb532_button_remove(struct platform_device *pdev)
{
struct input_polled_dev *poll_dev = dev_get_drvdata(&pdev->dev);
input_unregister_polled_device(poll_dev);
input_free_polled_device(poll_dev);
return 0;
}
static struct platform_driver rb532_button_driver = {
.probe = rb532_button_probe,
.remove = rb532_button_remove,
.driver = {
.name = DRV_NAME,
},
};
module_platform_driver(rb532_button_driver);
MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
MODULE_ALIAS("platform:" DRV_NAME);
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