166 lines
4.2 KiB
C
166 lines
4.2 KiB
C
/*
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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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return ret;
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ret = devm_gpio_request_one(&pdev->dev, extcon_data->gpio, GPIOF_DIR_IN,
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pdev->name);
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if (ret < 0)
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goto err;
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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;
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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;
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platform_set_drvdata(pdev, extcon_data);
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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:
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extcon_dev_unregister(&extcon_data->edev);
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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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free_irq(extcon_data->irq, extcon_data);
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extcon_dev_unregister(&extcon_data->edev);
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return 0;
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}
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static struct platform_driver gpio_extcon_driver = {
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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_driver);
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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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