--- /dev/null
+/*
+ * 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");
+
projects / openwrt / openwrt.git / blobdiff