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@@ -0,0 +1,206 @@
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+/*
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+ * Driver for buttons on GPIO lines not capable of generating interrupts
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+ *
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+ * Copyright (C) 2007,2008 Gabor Juhos <juhosg at openwrt.org>
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+ *
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+ * This file was based on: /drivers/input/misc/cobalt_btns.c
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+ * Copyright (C) 2007 Yoichi Yuasa <[email protected]>
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+ *
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+ * also was based on: /drivers/input/keyboard/gpio_keys.c
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+ * Copyright 2005 Phil Blundell
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License version 2 as
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+ * published by the Free Software Foundation.
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+ *
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+ */
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+
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+#include <linux/init.h>
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+#include <linux/input-polldev.h>
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+#include <linux/ioport.h>
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+#include <linux/module.h>
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+#include <linux/platform_device.h>
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+
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+#include <linux/gpio_buttons.h>
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+
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+#include <asm/gpio.h>
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+
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+#define DRV_NAME "gpio-buttons"
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+#define DRV_VERSION "0.1.0"
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+#define PFX DRV_NAME ": "
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+
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+struct gpio_buttons_dev {
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+ struct input_polled_dev *poll_dev;
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+ struct gpio_buttons_platform_data *pdata;
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+};
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+
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+static void gpio_buttons_poll(struct input_polled_dev *dev)
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+{
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+ struct gpio_buttons_dev *bdev = dev->private;
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+ struct gpio_buttons_platform_data *pdata = bdev->pdata;
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+ struct input_dev *input = dev->input;
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+ int i;
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+
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+ for (i = 0; i < bdev->pdata->nbuttons; i++) {
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+ struct gpio_button *button = &pdata->buttons[i];
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+ unsigned int type = button->type ?: EV_KEY;
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+ int state;
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+
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+ state = gpio_get_value(button->gpio) ? 1 : 0;
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+ state ^= button->active_low;
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+
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+ if (state) {
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+ button->count++;
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+ } else {
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+ if (button->count >= button->threshold) {
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+ input_event(input, type, button->code, 1);
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+ input_sync(input);
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+ }
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+ button->count = 0;
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+ }
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+
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+ if (button->count == button->threshold) {
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+ input_event(input, type, button->code, 0);
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+ input_sync(input);
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+ }
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+ }
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+}
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+
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+static int __devinit gpio_buttons_probe(struct platform_device *pdev)
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+{
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+ struct gpio_buttons_platform_data *pdata = pdev->dev.platform_data;
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+ struct gpio_buttons_dev *bdev;
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+ struct input_polled_dev *poll_dev;
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+ struct input_dev *input;
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+ int error, i;
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+
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+
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+ if (!pdata)
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+ return -ENXIO;
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+
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+ bdev = kzalloc(sizeof(*bdev), GFP_KERNEL);
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+ if (!bdev) {
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+ pr_err(DRV_NAME "no memory for device\n");
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+ return -ENOMEM;
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+ }
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+
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+ poll_dev = input_allocate_polled_device();
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+ if (!poll_dev) {
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+ pr_err(DRV_NAME "no memory for polled device\n");
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+ error = -ENOMEM;
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+ goto err_free_bdev;
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+ }
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+
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+ poll_dev->private = bdev;
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+ poll_dev->poll = gpio_buttons_poll;
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+ poll_dev->poll_interval = pdata->poll_interval;
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+
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+ input = poll_dev->input;
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+
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+ input->evbit[0] = BIT_MASK(EV_KEY);
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+ input->name = pdev->name;
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+ input->phys = "gpio-buttons/input0";
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+ input->dev.parent = &pdev->dev;
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+
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+ input->id.bustype = BUS_HOST;
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+ input->id.vendor = 0x0001;
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+ input->id.product = 0x0001;
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+ input->id.version = 0x0100;
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+
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+ for (i = 0; i < pdata->nbuttons; i++) {
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+ struct gpio_button *button = &pdata->buttons[i];
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+ unsigned int gpio = button->gpio;
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+ unsigned int type = button->type ?: EV_KEY;
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+
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+ error = gpio_request(gpio, button->desc ?
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+ button->desc : DRV_NAME);
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+ if (error) {
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+ pr_err(PFX "unable to claim gpio %u, error %d\n",
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+ gpio, error);
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+ goto err_free_gpio;
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+ }
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+
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+ error = gpio_direction_input(gpio);
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+ if (error) {
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+ pr_err(PFX "unable to set direction on gpio %u, "
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+ "error %d\n", gpio, error);
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+ goto err_free_gpio;
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+ }
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+
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+ input_set_capability(input, type, button->code);
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+ button->count = 0;
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+ }
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+
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+ bdev->poll_dev = poll_dev;
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+ bdev->pdata = pdata;
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+ platform_set_drvdata(pdev, bdev);
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+
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+ error = input_register_polled_device(poll_dev);
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+ if (error) {
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+ pr_err(PFX "unable to register polled device, error %d\n",
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+ error);
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+ goto err_free_gpio;
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+ }
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+
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+ return 0;
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+
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+err_free_gpio:
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+ for (i = i - 1; i >= 0; i--)
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+ gpio_free(pdata->buttons[i].gpio);
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+
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+ input_free_polled_device(poll_dev);
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+
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+err_free_bdev:
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+ kfree(bdev);
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+err:
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+ platform_set_drvdata(pdev, NULL);
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+ return error;
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+}
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+
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+static int __devexit gpio_buttons_remove(struct platform_device *pdev)
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+{
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+ struct gpio_buttons_dev *bdev = platform_get_drvdata(pdev);
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+ struct gpio_buttons_platform_data *pdata = bdev->pdata;
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+ int i;
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+
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+ input_unregister_polled_device(bdev->poll_dev);
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+
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+ for (i = 0; i < pdata->nbuttons; i++)
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+ gpio_free(pdata->buttons[i].gpio);
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+
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+ input_free_polled_device(bdev->poll_dev);
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+
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+ kfree(bdev);
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+ platform_set_drvdata(pdev, NULL);
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+
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+ return 0;
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+}
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+
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+static struct platform_driver gpio_buttons_driver = {
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+ .probe = gpio_buttons_probe,
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+ .remove = __devexit_p(gpio_buttons_remove),
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+ .driver = {
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+ .name = DRV_NAME,
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+ .owner = THIS_MODULE,
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+ },
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+};
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+
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+static int __init gpio_buttons_init(void)
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+{
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+ pr_info(DRV_NAME " driver version " DRV_VERSION "\n");
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+ return platform_driver_register(&gpio_buttons_driver);
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+}
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+
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+static void __exit gpio_buttons_exit(void)
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+{
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+ platform_driver_unregister(&gpio_buttons_driver);
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+}
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+
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+module_init(gpio_buttons_init);
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+module_exit(gpio_buttons_exit);
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+
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+MODULE_LICENSE("GPL");
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+MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
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+MODULE_VERSION(DRV_VERSION);
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+MODULE_DESCRIPTION("Polled buttons driver for CPU GPIOs");
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+
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Gabor Juhos