/* * Driver for buttons on GPIO lines not capable of generating interrupts * * Copyright (C) 2007,2008 Gabor Juhos <juhosg at openwrt.org> * * This file was based on: /drivers/input/misc/cobalt_btns.c * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> * * also was based on: /drivers/input/keyboard/gpio_keys.c * Copyright 2005 Phil Blundell * * 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/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/input.h> #include <linux/input-polldev.h> #include <linux/ioport.h> #include <linux/platform_device.h> #include <linux/gpio_buttons.h> #include <asm/gpio.h> #define DRV_NAME "gpio-buttons" #define DRV_VERSION "0.1.1" #define PFX DRV_NAME ": " struct gpio_buttons_dev { struct input_polled_dev *poll_dev; struct gpio_buttons_platform_data *pdata; }; static void gpio_buttons_poll(struct input_polled_dev *dev) { struct gpio_buttons_dev *bdev = dev->private; struct gpio_buttons_platform_data *pdata = bdev->pdata; struct input_dev *input = dev->input; int i; for (i = 0; i < bdev->pdata->nbuttons; i++) { struct gpio_button *button = &pdata->buttons[i]; unsigned int type = button->type ?: EV_KEY; int state; state = gpio_get_value(button->gpio) ? 1 : 0; state ^= button->active_low; if (state) { button->count++; } else { if (button->count >= button->threshold) { input_event(input, type, button->code, 1); input_sync(input); } button->count = 0; } if (button->count == button->threshold) { input_event(input, type, button->code, 0); input_sync(input); } } } static int __devinit gpio_buttons_probe(struct platform_device *pdev) { struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data; struct gpio_buttons_dev *bdev; struct input_polled_dev *poll_dev; struct input_dev *input; int error, i; if (!pdata) return -ENXIO; bdev = kzalloc(sizeof(*bdev), GFP_KERNEL); if (!bdev) { printk(KERN_ERR DRV_NAME "no memory for device\n"); return -ENOMEM; } poll_dev = input_allocate_polled_device(); if (!poll_dev) { printk(KERN_ERR DRV_NAME "no memory for polled device\n"); error = -ENOMEM; goto err_free_bdev; } poll_dev->private = bdev; poll_dev->poll = gpio_buttons_poll; poll_dev->poll_interval = pdata->poll_interval; input = poll_dev->input; input->evbit[0] = BIT(EV_KEY); input->name = pdev->name; input->phys = "gpio-buttons/input0"; input->dev.parent = &pdev->dev; input->id.bustype = BUS_HOST; input->id.vendor = 0x0001; input->id.product = 0x0001; input->id.version = 0x0100; for (i = 0; i < pdata->nbuttons; i++) { struct gpio_button *button = &pdata->buttons[i]; unsigned int gpio = button->gpio; unsigned int type = button->type ?: EV_KEY; error = gpio_request(gpio, button->desc ? button->desc : DRV_NAME); if (error) { printk(KERN_ERR PFX "unable to claim gpio %u, " "error %d\n", gpio, error); goto err_free_gpio; } error = gpio_direction_input(gpio); if (error) { printk(KERN_ERR PFX "unable to set direction on " "gpio %u, error %d\n", gpio, error); goto err_free_gpio; } input_set_capability(input, type, button->code); button->count = 0; } bdev->poll_dev = poll_dev; bdev->pdata = pdata; platform_set_drvdata(pdev, bdev); error = input_register_polled_device(poll_dev); if (error) { printk(KERN_ERR PFX "unable to register polled device, " "error %d\n", error); goto err_free_gpio; } return 0; err_free_gpio: for (i = i - 1; i >= 0; i--) gpio_free(pdata->buttons[i].gpio); input_free_polled_device(poll_dev); err_free_bdev: kfree(bdev); platform_set_drvdata(pdev, NULL); return error; } static int __devexit gpio_buttons_remove(struct platform_device *pdev) { struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev); struct gpio_buttons_platform_data *pdata = bdev->pdata; int i; input_unregister_polled_device(bdev->poll_dev); for (i = 0; i < pdata->nbuttons; i++) gpio_free(pdata->buttons[i].gpio); input_free_polled_device(bdev->poll_dev); kfree(bdev); platform_set_drvdata(pdev, NULL); return 0; } static struct platform_driver gpio_buttons_driver = { .probe = gpio_buttons_probe, .remove = __devexit_p(gpio_buttons_remove), .driver = { .name = DRV_NAME, .owner = THIS_MODULE, }, }; static int __init gpio_buttons_init(void) { printk(KERN_INFO DRV_NAME " driver version " DRV_VERSION "\n"); return platform_driver_register(&gpio_buttons_driver); } static void __exit gpio_buttons_exit(void) { platform_driver_unregister(&gpio_buttons_driver); } module_init(gpio_buttons_init); module_exit(gpio_buttons_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>"); MODULE_VERSION(DRV_VERSION); MODULE_DESCRIPTION("Polled buttons driver for CPU GPIOs");