/* * 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);