The existing gpio-keys driver can be usable only for GPIO lines with interrupt support. Several devices have buttons connected to a GPIO line which is not capable to generate interrupts. This patch adds a new input driver using the generic GPIO layer and the input-polldev to support such buttons. [Ben Gardiner <bengardiner@nanometrics.ca: fold code to use more of the original gpio_keys infrastructure; cleanups and other improvements.] Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca> Tested-by: Ben Gardiner <bengardiner@nanometrics.ca> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>tirimbino
Gabor Juhos
14 years ago
committed by
Dmitry Torokhov
parent
8ed9e0e1b6
commit
0e7d0c860a
@ -0,0 +1,261 @@ |
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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) 2007-2010 Gabor Juhos <juhosg@openwrt.org> |
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* Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com> |
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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 <yoichi_yuasa@tripeaks.co.jp> |
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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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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/init.h> |
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#include <linux/slab.h> |
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#include <linux/input.h> |
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#include <linux/input-polldev.h> |
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#include <linux/ioport.h> |
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#include <linux/platform_device.h> |
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#include <linux/gpio.h> |
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#include <linux/gpio_keys.h> |
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#define DRV_NAME "gpio-keys-polled" |
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struct gpio_keys_button_data { |
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int last_state; |
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int count; |
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int threshold; |
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int can_sleep; |
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}; |
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struct gpio_keys_polled_dev { |
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struct input_polled_dev *poll_dev; |
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struct device *dev; |
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struct gpio_keys_platform_data *pdata; |
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struct gpio_keys_button_data data[0]; |
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}; |
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static void gpio_keys_polled_check_state(struct input_dev *input, |
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struct gpio_keys_button *button, |
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struct gpio_keys_button_data *bdata) |
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{ |
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int state; |
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if (bdata->can_sleep) |
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state = !!gpio_get_value_cansleep(button->gpio); |
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else |
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state = !!gpio_get_value(button->gpio); |
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if (state != bdata->last_state) { |
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unsigned int type = button->type ?: EV_KEY; |
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input_event(input, type, button->code, |
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!!(state ^ button->active_low)); |
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input_sync(input); |
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bdata->count = 0; |
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bdata->last_state = state; |
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} |
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} |
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static void gpio_keys_polled_poll(struct input_polled_dev *dev) |
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{ |
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struct gpio_keys_polled_dev *bdev = dev->private; |
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struct gpio_keys_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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for (i = 0; i < bdev->pdata->nbuttons; i++) { |
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struct gpio_keys_button_data *bdata = &bdev->data[i]; |
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if (bdata->count < bdata->threshold) |
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bdata->count++; |
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else |
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gpio_keys_polled_check_state(input, &pdata->buttons[i], |
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bdata); |
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} |
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} |
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static void gpio_keys_polled_open(struct input_polled_dev *dev) |
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{ |
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struct gpio_keys_polled_dev *bdev = dev->private; |
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struct gpio_keys_platform_data *pdata = bdev->pdata; |
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if (pdata->enable) |
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pdata->enable(bdev->dev); |
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} |
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static void gpio_keys_polled_close(struct input_polled_dev *dev) |
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{ |
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struct gpio_keys_polled_dev *bdev = dev->private; |
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struct gpio_keys_platform_data *pdata = bdev->pdata; |
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if (pdata->disable) |
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pdata->disable(bdev->dev); |
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} |
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static int __devinit gpio_keys_polled_probe(struct platform_device *pdev) |
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{ |
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struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; |
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struct device *dev = &pdev->dev; |
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struct gpio_keys_polled_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; |
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int i; |
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if (!pdata || !pdata->poll_interval) |
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return -EINVAL; |
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bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) + |
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pdata->nbuttons * sizeof(struct gpio_keys_button_data), |
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GFP_KERNEL); |
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if (!bdev) { |
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dev_err(dev, "no memory for private data\n"); |
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return -ENOMEM; |
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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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dev_err(dev, "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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poll_dev->private = bdev; |
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poll_dev->poll = gpio_keys_polled_poll; |
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poll_dev->poll_interval = pdata->poll_interval; |
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poll_dev->open = gpio_keys_polled_open; |
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poll_dev->close = gpio_keys_polled_close; |
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input = poll_dev->input; |
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input->evbit[0] = BIT(EV_KEY); |
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input->name = pdev->name; |
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input->phys = DRV_NAME"/input0"; |
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input->dev.parent = &pdev->dev; |
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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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for (i = 0; i < pdata->nbuttons; i++) { |
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struct gpio_keys_button *button = &pdata->buttons[i]; |
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struct gpio_keys_button_data *bdata = &bdev->data[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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if (button->wakeup) { |
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dev_err(dev, DRV_NAME " does not support wakeup\n"); |
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error = -EINVAL; |
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goto err_free_gpio; |
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} |
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error = gpio_request(gpio, |
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button->desc ? button->desc : DRV_NAME); |
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if (error) { |
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dev_err(dev, "unable to claim gpio %u, err=%d\n", |
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gpio, error); |
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goto err_free_gpio; |
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} |
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error = gpio_direction_input(gpio); |
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if (error) { |
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dev_err(dev, |
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"unable to set direction on gpio %u, err=%d\n", |
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gpio, error); |
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goto err_free_gpio; |
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} |
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bdata->can_sleep = gpio_cansleep(gpio); |
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bdata->last_state = -1; |
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bdata->threshold = DIV_ROUND_UP(button->debounce_interval, |
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pdata->poll_interval); |
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input_set_capability(input, type, button->code); |
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} |
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bdev->poll_dev = poll_dev; |
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bdev->dev = dev; |
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bdev->pdata = pdata; |
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platform_set_drvdata(pdev, bdev); |
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error = input_register_polled_device(poll_dev); |
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if (error) { |
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dev_err(dev, "unable to register polled device, err=%d\n", |
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error); |
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goto err_free_gpio; |
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} |
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/* report initial state of the buttons */ |
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for (i = 0; i < pdata->nbuttons; i++) |
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gpio_keys_polled_check_state(input, &pdata->buttons[i], |
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&bdev->data[i]); |
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return 0; |
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err_free_gpio: |
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while (--i >= 0) |
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gpio_free(pdata->buttons[i].gpio); |
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input_free_polled_device(poll_dev); |
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err_free_bdev: |
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kfree(bdev); |
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platform_set_drvdata(pdev, NULL); |
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return error; |
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} |
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static int __devexit gpio_keys_polled_remove(struct platform_device *pdev) |
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{ |
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struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev); |
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struct gpio_keys_platform_data *pdata = bdev->pdata; |
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int i; |
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input_unregister_polled_device(bdev->poll_dev); |
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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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input_free_polled_device(bdev->poll_dev); |
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kfree(bdev); |
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platform_set_drvdata(pdev, NULL); |
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return 0; |
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} |
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static struct platform_driver gpio_keys_polled_driver = { |
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.probe = gpio_keys_polled_probe, |
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.remove = __devexit_p(gpio_keys_polled_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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static int __init gpio_keys_polled_init(void) |
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{ |
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return platform_driver_register(&gpio_keys_polled_driver); |
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} |
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static void __exit gpio_keys_polled_exit(void) |
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{ |
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platform_driver_unregister(&gpio_keys_polled_driver); |
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} |
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module_init(gpio_keys_polled_init); |
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module_exit(gpio_keys_polled_exit); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); |
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MODULE_DESCRIPTION("Polled GPIO Buttons driver"); |
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MODULE_ALIAS("platform:" DRV_NAME); |
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