/* * 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 <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,		.owner = THIS_MODULE,	},};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);