Extcon: support generic GPIO extcon driver
The generic GPIO extcon driver (an external connector device based on GPIO control) and imported from Android kernel. switch: switch class and GPIO drivers. (splitted) Author: Mike Lockwood <lockwood@android.com> switch: gpio: Don't call request_irq with interrupts disabled Author: Arve Hjønnevåg <arve@android.com> switch_gpio: Add missing #include <linux/interrupt.h> Author: Mike Lockwood <lockwood@android.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> -- Changed from v7: - Style updates mentioned by Stephen Boyd and Mark Brown Changed from v5: - Splitted at v5 from the main extcon patch. - Added debounce time for irq handlers. - Use request_any_context_irq instead of request_irq - User needs to specify irq flags for GPIO interrupts (was fixed to IRQF_TRIGGER_LOW before) - Use module_platform_driver(). Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>hifive-unleashed-5.1
MyungJoo Ham
Greg Kroah-Hartman
parent
de55d8716a
commit
be48308a24
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@ -14,4 +14,11 @@ if EXTCON
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comment "Extcon Device Drivers"
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config EXTCON_GPIO
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tristate "GPIO extcon support"
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depends on GENERIC_GPIO
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help
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Say Y here to enable GPIO based extcon support. Note that GPIO
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extcon supports single state per extcon instance.
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endif # MULTISTATE_SWITCH
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@ -3,3 +3,4 @@
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#
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obj-$(CONFIG_EXTCON) += extcon_class.o
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obj-$(CONFIG_EXTCON_GPIO) += extcon_gpio.o
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@ -0,0 +1,169 @@
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/*
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* drivers/extcon/extcon_gpio.c
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*
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* Single-state GPIO extcon driver based on extcon class
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*
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* Copyright (C) 2008 Google, Inc.
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* Author: Mike Lockwood <lockwood@android.com>
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*
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* Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
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* (originally switch class is supported)
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/extcon.h>
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#include <linux/workqueue.h>
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#include <linux/gpio.h>
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#include <linux/extcon.h>
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#include <linux/extcon/extcon_gpio.h>
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struct gpio_extcon_data {
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struct extcon_dev edev;
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unsigned gpio;
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const char *state_on;
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const char *state_off;
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int irq;
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struct delayed_work work;
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unsigned long debounce_jiffies;
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};
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static void gpio_extcon_work(struct work_struct *work)
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{
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int state;
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struct gpio_extcon_data *data =
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container_of(to_delayed_work(work), struct gpio_extcon_data,
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work);
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state = gpio_get_value(data->gpio);
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extcon_set_state(&data->edev, state);
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}
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static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
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{
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struct gpio_extcon_data *extcon_data = dev_id;
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schedule_delayed_work(&extcon_data->work,
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extcon_data->debounce_jiffies);
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return IRQ_HANDLED;
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}
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static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
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{
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struct gpio_extcon_data *extcon_data =
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container_of(edev, struct gpio_extcon_data, edev);
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const char *state;
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if (extcon_get_state(edev))
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state = extcon_data->state_on;
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else
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state = extcon_data->state_off;
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if (state)
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return sprintf(buf, "%s\n", state);
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return -EINVAL;
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}
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static int __devinit gpio_extcon_probe(struct platform_device *pdev)
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{
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struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
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struct gpio_extcon_data *extcon_data;
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int ret = 0;
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if (!pdata)
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return -EBUSY;
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if (!pdata->irq_flags) {
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dev_err(&pdev->dev, "IRQ flag is not specified.\n");
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return -EINVAL;
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}
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extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
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GFP_KERNEL);
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if (!extcon_data)
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return -ENOMEM;
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extcon_data->edev.name = pdata->name;
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extcon_data->gpio = pdata->gpio;
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extcon_data->state_on = pdata->state_on;
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extcon_data->state_off = pdata->state_off;
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if (pdata->state_on && pdata->state_off)
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extcon_data->edev.print_state = extcon_gpio_print_state;
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extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
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ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
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if (ret < 0)
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goto err_extcon_dev_register;
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ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name);
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if (ret < 0)
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goto err_request_gpio;
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INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
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extcon_data->irq = gpio_to_irq(extcon_data->gpio);
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if (extcon_data->irq < 0) {
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ret = extcon_data->irq;
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goto err_detect_irq_num_failed;
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}
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ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
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pdata->irq_flags, pdev->name,
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extcon_data);
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if (ret < 0)
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goto err_request_irq;
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/* Perform initial detection */
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gpio_extcon_work(&extcon_data->work.work);
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return 0;
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err_request_irq:
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err_detect_irq_num_failed:
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gpio_free(extcon_data->gpio);
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err_request_gpio:
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extcon_dev_unregister(&extcon_data->edev);
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err_extcon_dev_register:
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devm_kfree(&pdev->dev, extcon_data);
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return ret;
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}
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static int __devexit gpio_extcon_remove(struct platform_device *pdev)
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{
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struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
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cancel_delayed_work_sync(&extcon_data->work);
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gpio_free(extcon_data->gpio);
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extcon_dev_unregister(&extcon_data->edev);
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devm_kfree(&pdev->dev, extcon_data);
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return 0;
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}
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static struct platform_driver gpio_extcon = {
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.probe = gpio_extcon_probe,
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.remove = __devexit_p(gpio_extcon_remove),
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.driver = {
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.name = "extcon-gpio",
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.owner = THIS_MODULE,
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},
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};
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module_platform_driver(gpio_extcon);
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MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
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MODULE_DESCRIPTION("GPIO extcon driver");
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MODULE_LICENSE("GPL");
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@ -0,0 +1,52 @@
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/*
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* External connector (extcon) class generic GPIO driver
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*
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* Copyright (C) 2012 Samsung Electronics
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* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
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*
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* based on switch class driver
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* Copyright (C) 2008 Google, Inc.
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* Author: Mike Lockwood <lockwood@android.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#ifndef __EXTCON_GPIO_H__
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#define __EXTCON_GPIO_H__ __FILE__
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#include <linux/extcon.h>
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/**
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* struct gpio_extcon_platform_data - A simple GPIO-controlled extcon device.
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* @name The name of this GPIO extcon device.
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* @gpio Corresponding GPIO.
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* @debounce Debounce time for GPIO IRQ in ms.
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* @irq_flags IRQ Flags (e.g., IRQF_TRIGGER_LOW).
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* @state_on print_state is overriden with state_on if attached. If Null,
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* default method of extcon class is used.
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* @state_off print_state is overriden with state_on if dettached. If Null,
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* default method of extcon class is used.
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*
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* Note that in order for state_on or state_off to be valid, both state_on
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* and state_off should be not NULL. If at least one of them is NULL,
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* the print_state is not overriden.
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*/
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struct gpio_extcon_platform_data {
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const char *name;
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unsigned gpio;
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unsigned long debounce;
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unsigned long irq_flags;
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/* if NULL, "0" or "1" will be printed */
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const char *state_on;
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const char *state_off;
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};
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#endif /* __EXTCON_GPIO_H__ */
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