Extcon: support generic GPIO extcon driver (be48308a) · Commits · 戴 / test

drivers/extcon/Kconfig

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		@@ -14,4 +14,11 @@ if EXTCON

		comment "Extcon Device Drivers"

		config EXTCON_GPIO
		tristate "GPIO extcon support"
		depends on GENERIC_GPIO
		help
		Say Y here to enable GPIO based extcon support. Note that GPIO
		extcon supports single state per extcon instance.

		endif # MULTISTATE_SWITCH

drivers/extcon/Makefile

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		@@ -3,3 +3,4 @@
		#

		obj-$(CONFIG_EXTCON) += extcon_class.o
		obj-$(CONFIG_EXTCON_GPIO) += extcon_gpio.o

drivers/extcon/extcon_gpio.c

0 → 100644

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Original line number	Diff line number	Diff line
		/*
		* drivers/extcon/extcon_gpio.c
		*
		* Single-state GPIO extcon driver based on extcon class
		*
		* Copyright (C) 2008 Google, Inc.
		* Author: Mike Lockwood <lockwood@android.com>
		*
		* Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
		* (originally switch class is supported)
		*
		* This software is licensed under the terms of the GNU General Public
		* License version 2, as published by the Free Software Foundation, and
		* may be copied, distributed, and modified under those terms.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		*/

		#include <linux/module.h>
		#include <linux/kernel.h>
		#include <linux/init.h>
		#include <linux/interrupt.h>
		#include <linux/platform_device.h>
		#include <linux/slab.h>
		#include <linux/extcon.h>
		#include <linux/workqueue.h>
		#include <linux/gpio.h>
		#include <linux/extcon.h>
		#include <linux/extcon/extcon_gpio.h>

		struct gpio_extcon_data {
		struct extcon_dev edev;
		unsigned gpio;
		const char *state_on;
		const char *state_off;
		int irq;
		struct delayed_work work;
		unsigned long debounce_jiffies;
		};

		static void gpio_extcon_work(struct work_struct *work)
		{
		int state;
		struct gpio_extcon_data *data =
		container_of(to_delayed_work(work), struct gpio_extcon_data,
		work);

		state = gpio_get_value(data->gpio);
		extcon_set_state(&data->edev, state);
		}

		static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
		{
		struct gpio_extcon_data *extcon_data = dev_id;

		schedule_delayed_work(&extcon_data->work,
		extcon_data->debounce_jiffies);
		return IRQ_HANDLED;
		}

		static ssize_t extcon_gpio_print_state(struct extcon_dev edev, char buf)
		{
		struct gpio_extcon_data *extcon_data =
		container_of(edev, struct gpio_extcon_data, edev);
		const char *state;
		if (extcon_get_state(edev))
		state = extcon_data->state_on;
		else
		state = extcon_data->state_off;

		if (state)
		return sprintf(buf, "%s\n", state);
		return -EINVAL;
		}

		static int __devinit gpio_extcon_probe(struct platform_device *pdev)
		{
		struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
		struct gpio_extcon_data *extcon_data;
		int ret = 0;

		if (!pdata)
		return -EBUSY;
		if (!pdata->irq_flags) {
		dev_err(&pdev->dev, "IRQ flag is not specified.\n");
		return -EINVAL;
		}

		extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
		GFP_KERNEL);
		if (!extcon_data)
		return -ENOMEM;

		extcon_data->edev.name = pdata->name;
		extcon_data->gpio = pdata->gpio;
		extcon_data->state_on = pdata->state_on;
		extcon_data->state_off = pdata->state_off;
		if (pdata->state_on && pdata->state_off)
		extcon_data->edev.print_state = extcon_gpio_print_state;
		extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);

		ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
		if (ret < 0)
		goto err_extcon_dev_register;

		ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name);
		if (ret < 0)
		goto err_request_gpio;

		INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);

		extcon_data->irq = gpio_to_irq(extcon_data->gpio);
		if (extcon_data->irq < 0) {
		ret = extcon_data->irq;
		goto err_detect_irq_num_failed;
		}

		ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
		pdata->irq_flags, pdev->name,
		extcon_data);
		if (ret < 0)
		goto err_request_irq;

		/* Perform initial detection */
		gpio_extcon_work(&extcon_data->work.work);

		return 0;

		err_request_irq:
		err_detect_irq_num_failed:
		gpio_free(extcon_data->gpio);
		err_request_gpio:
		extcon_dev_unregister(&extcon_data->edev);
		err_extcon_dev_register:
		devm_kfree(&pdev->dev, extcon_data);

		return ret;
		}

		static int __devexit gpio_extcon_remove(struct platform_device *pdev)
		{
		struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);

		cancel_delayed_work_sync(&extcon_data->work);
		gpio_free(extcon_data->gpio);
		extcon_dev_unregister(&extcon_data->edev);
		devm_kfree(&pdev->dev, extcon_data);

		return 0;
		}

		static struct platform_driver gpio_extcon = {
		.probe = gpio_extcon_probe,
		.remove = __devexit_p(gpio_extcon_remove),
		.driver = {
		.name = "extcon-gpio",
		.owner = THIS_MODULE,
		},
		};

		module_platform_driver(gpio_extcon);

		MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
		MODULE_DESCRIPTION("GPIO extcon driver");
		MODULE_LICENSE("GPL");

include/linux/extcon/extcon_gpio.h

0 → 100644

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		/*
		* External connector (extcon) class generic GPIO driver
		*
		* Copyright (C) 2012 Samsung Electronics
		* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
		*
		* based on switch class driver
		* Copyright (C) 2008 Google, Inc.
		* Author: Mike Lockwood <lockwood@android.com>
		*
		* This software is licensed under the terms of the GNU General Public
		* License version 2, as published by the Free Software Foundation, and
		* may be copied, distributed, and modified under those terms.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		*/
		#ifndef __EXTCON_GPIO_H__
		#define __EXTCON_GPIO_H__ __FILE__

		#include <linux/extcon.h>

		/**
		* struct gpio_extcon_platform_data - A simple GPIO-controlled extcon device.
		* @name The name of this GPIO extcon device.
		* @gpio Corresponding GPIO.
		* @debounce Debounce time for GPIO IRQ in ms.
		* @irq_flags IRQ Flags (e.g., IRQF_TRIGGER_LOW).
		* @state_on print_state is overriden with state_on if attached. If Null,
		* default method of extcon class is used.
		* @state_off print_state is overriden with state_on if dettached. If Null,
		* default method of extcon class is used.
		*
		* Note that in order for state_on or state_off to be valid, both state_on
		* and state_off should be not NULL. If at least one of them is NULL,
		* the print_state is not overriden.
		*/
		struct gpio_extcon_platform_data {
		const char *name;
		unsigned gpio;
		unsigned long debounce;
		unsigned long irq_flags;

		/* if NULL, "0" or "1" will be printed */
		const char *state_on;
		const char *state_off;
		};

		#endif /* __EXTCON_GPIO_H__ */

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