// SPDX-License-Identifier: GPL-2.0-only/* * 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) */ #include <linux/devm-helpers.h>#include <linux/extcon-provider.h>#include <linux/gpio/consumer.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/platform_device.h>#include <linux/slab.h>#include <linux/workqueue.h> /** * struct gpio_extcon_data - A simple GPIO-controlled extcon device state container. * @edev:		Extcon device. * @work:		Work fired by the interrupt. * @debounce_jiffies:	Number of jiffies to wait for the GPIO to stabilize, from the debounce *			value. * @gpiod:		GPIO descriptor for this external connector. * @extcon_id:		The unique id of specific external connector. * @debounce:		Debounce time for GPIO IRQ in ms. * @check_on_resume:	Boolean describing whether to check the state of gpio *			while resuming from sleep. */struct gpio_extcon_data {	struct extcon_dev *edev;	struct delayed_work work;	unsigned long debounce_jiffies;	struct gpio_desc *gpiod;	unsigned int extcon_id;	unsigned long debounce;	bool check_on_resume;}; 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 = gpiod_get_value_cansleep(data->gpiod);	extcon_set_state_sync(data->edev, data->extcon_id, state);} static irqreturn_t gpio_irq_handler(int irq, void *dev_id){	struct gpio_extcon_data *data = dev_id; 	queue_delayed_work(system_power_efficient_wq, &data->work,			      data->debounce_jiffies);	return IRQ_HANDLED;} static int gpio_extcon_probe(struct platform_device *pdev){	struct gpio_extcon_data *data;	struct device *dev = &pdev->dev;	unsigned long irq_flags;	int irq;	int ret; 	data = devm_kzalloc(dev, sizeof(struct gpio_extcon_data), GFP_KERNEL);	if (!data)		return -ENOMEM; 	/*	 * FIXME: extcon_id represents the unique identifier of external	 * connectors such as EXTCON_USB, EXTCON_DISP_HDMI and so on. extcon_id	 * is necessary to register the extcon device. But, it's not yet	 * developed to get the extcon id from device-tree or others.	 * On later, it have to be solved.	 */	if (data->extcon_id > EXTCON_NONE)		return -EINVAL; 	data->gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);	if (IS_ERR(data->gpiod))		return PTR_ERR(data->gpiod);	irq = gpiod_to_irq(data->gpiod);	if (irq <= 0)		return irq; 	/*	 * It is unlikely that this is an acknowledged interrupt that goes	 * away after handling, what we are looking for are falling edges	 * if the signal is active low, and rising edges if the signal is	 * active high.	 */	if (gpiod_is_active_low(data->gpiod))		irq_flags = IRQF_TRIGGER_FALLING;	else		irq_flags = IRQF_TRIGGER_RISING; 	/* Allocate the memory of extcon devie and register extcon device */	data->edev = devm_extcon_dev_allocate(dev, &data->extcon_id);	if (IS_ERR(data->edev)) {		dev_err(dev, "failed to allocate extcon device\n");		return -ENOMEM;	} 	ret = devm_extcon_dev_register(dev, data->edev);	if (ret < 0)		return ret; 	ret = devm_delayed_work_autocancel(dev, &data->work, gpio_extcon_work);	if (ret)		return ret; 	/*	 * Request the interrupt of gpio to detect whether external connector	 * is attached or detached.	 */	ret = devm_request_any_context_irq(dev, irq,					gpio_irq_handler, irq_flags,					pdev->name, data);	if (ret < 0)		return ret; 	platform_set_drvdata(pdev, data);	/* Perform initial detection */	gpio_extcon_work(&data->work.work); 	return 0;} #ifdef CONFIG_PM_SLEEPstatic int gpio_extcon_resume(struct device *dev){	struct gpio_extcon_data *data; 	data = dev_get_drvdata(dev);	if (data->check_on_resume)		queue_delayed_work(system_power_efficient_wq,			&data->work, data->debounce_jiffies); 	return 0;}#endif static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume); static struct platform_driver gpio_extcon_driver = {	.probe		= gpio_extcon_probe,	.driver		= {		.name	= "extcon-gpio",		.pm	= &gpio_extcon_pm_ops,	},}; module_platform_driver(gpio_extcon_driver); MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");MODULE_DESCRIPTION("GPIO extcon driver");MODULE_LICENSE("GPL");