drivers/extcon/extcon-usb-gpio.c - arm/linux - Git at Google

 /**
  * drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
  *
  * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
  * Author: Roger Quadros <rogerq@ti.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * 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/extcon.h>
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/pinctrl/consumer.h>

 #define USB_GPIO_DEBOUNCE_MS	20	/* ms */

 struct usb_extcon_info {
 	struct device *dev;
 	struct extcon_dev *edev;

 	struct gpio_desc *id_gpiod;
 	struct gpio_desc *vbus_gpiod;
 	int id_irq;
 	int vbus_irq;

 	unsigned long debounce_jiffies;
 	struct delayed_work wq_detcable;
 };

 static const unsigned int usb_extcon_cable[] = {
 	EXTCON_USB,
 	EXTCON_USB_HOST,
 	EXTCON_NONE,
 };

 /*
  * "USB" = VBUS and "USB-HOST" = !ID, so we have:
  * Both "USB" and "USB-HOST" can't be set as active at the
  * same time so if "USB-HOST" is active (i.e. ID is 0)  we keep "USB" inactive
  * even if VBUS is on.
  *
  *  State              |    ID   |   VBUS
  * ----------------------------------------
  *  [1] USB            |    H    |    H
  *  [2] none           |    H    |    L
  *  [3] USB-HOST       |    L    |    H
  *  [4] USB-HOST       |    L    |    L
  *
  * In case we have only one of these signals:
  * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
  * - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
 */
 static void usb_extcon_detect_cable(struct work_struct *work)
 {
 	int id, vbus;
 	struct usb_extcon_info *info = container_of(to_delayed_work(work),
 						    struct usb_extcon_info,
 						    wq_detcable);

 	/* check ID and VBUS and update cable state */
 	id = info->id_gpiod ?
 		gpiod_get_value_cansleep(info->id_gpiod) : 1;
 	vbus = info->vbus_gpiod ?
 		gpiod_get_value_cansleep(info->vbus_gpiod) : id;

 	/* at first we clean states which are no longer active */
 	if (id)
 		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
 	if (!vbus)
 		extcon_set_state_sync(info->edev, EXTCON_USB, false);

 	if (!id) {
 		extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
 	} else {
 		if (vbus)
 			extcon_set_state_sync(info->edev, EXTCON_USB, true);
 	}
 }

 static irqreturn_t usb_irq_handler(int irq, void *dev_id)
 {
 	struct usb_extcon_info *info = dev_id;

 	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
 			   info->debounce_jiffies);

 	return IRQ_HANDLED;
 }

 static int usb_extcon_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct usb_extcon_info *info;
 	int ret;

 	if (!np)
 		return -EINVAL;

 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;

 	info->dev = dev;
 	info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
 	info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
 						   GPIOD_IN);

 	if (!info->id_gpiod && !info->vbus_gpiod) {
 		dev_err(dev, "failed to get gpios\n");
 		return -ENODEV;
 	}

 	if (IS_ERR(info->id_gpiod))
 		return PTR_ERR(info->id_gpiod);

 	if (IS_ERR(info->vbus_gpiod))
 		return PTR_ERR(info->vbus_gpiod);

 	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
 	if (IS_ERR(info->edev)) {
 		dev_err(dev, "failed to allocate extcon device\n");
 		return -ENOMEM;
 	}

 	ret = devm_extcon_dev_register(dev, info->edev);
 	if (ret < 0) {
 		dev_err(dev, "failed to register extcon device\n");
 		return ret;
 	}

 	if (info->id_gpiod)
 		ret = gpiod_set_debounce(info->id_gpiod,
 					 USB_GPIO_DEBOUNCE_MS * 1000);
 	if (!ret && info->vbus_gpiod)
 		ret = gpiod_set_debounce(info->vbus_gpiod,
 					 USB_GPIO_DEBOUNCE_MS * 1000);

 	if (ret < 0)
 		info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);

 	INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);

 	if (info->id_gpiod) {
 		info->id_irq = gpiod_to_irq(info->id_gpiod);
 		if (info->id_irq < 0) {
 			dev_err(dev, "failed to get ID IRQ\n");
 			return info->id_irq;
 		}

 		ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
 						usb_irq_handler,
 						IRQF_TRIGGER_RISING |
 						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 						pdev->name, info);
 		if (ret < 0) {
 			dev_err(dev, "failed to request handler for ID IRQ\n");
 			return ret;
 		}
 	}

 	if (info->vbus_gpiod) {
 		info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
 		if (info->vbus_irq < 0) {
 			dev_err(dev, "failed to get VBUS IRQ\n");
 			return info->vbus_irq;
 		}

 		ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
 						usb_irq_handler,
 						IRQF_TRIGGER_RISING |
 						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 						pdev->name, info);
 		if (ret < 0) {
 			dev_err(dev, "failed to request handler for VBUS IRQ\n");
 			return ret;
 		}
 	}

 	platform_set_drvdata(pdev, info);
 	device_set_wakeup_capable(&pdev->dev, true);

 	/* Perform initial detection */
 	usb_extcon_detect_cable(&info->wq_detcable.work);

 	return 0;
 }

 static int usb_extcon_remove(struct platform_device *pdev)
 {
 	struct usb_extcon_info *info = platform_get_drvdata(pdev);

 	cancel_delayed_work_sync(&info->wq_detcable);
 	device_init_wakeup(&pdev->dev, false);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int usb_extcon_suspend(struct device *dev)
 {
 	struct usb_extcon_info *info = dev_get_drvdata(dev);
 	int ret = 0;

 	if (device_may_wakeup(dev)) {
 		if (info->id_gpiod) {
 			ret = enable_irq_wake(info->id_irq);
 			if (ret)
 				return ret;
 		}
 		if (info->vbus_gpiod) {
 			ret = enable_irq_wake(info->vbus_irq);
 			if (ret) {
 				if (info->id_gpiod)
 					disable_irq_wake(info->id_irq);

 				return ret;
 			}
 		}
 	}

 	/*
 	 * We don't want to process any IRQs after this point
 	 * as GPIOs used behind I2C subsystem might not be
 	 * accessible until resume completes. So disable IRQ.
 	 */
 	if (info->id_gpiod)
 		disable_irq(info->id_irq);
 	if (info->vbus_gpiod)
 		disable_irq(info->vbus_irq);

 	if (!device_may_wakeup(dev))
 		pinctrl_pm_select_sleep_state(dev);

 	return ret;
 }

 static int usb_extcon_resume(struct device *dev)
 {
 	struct usb_extcon_info *info = dev_get_drvdata(dev);
 	int ret = 0;

 	if (!device_may_wakeup(dev))
 		pinctrl_pm_select_default_state(dev);

 	if (device_may_wakeup(dev)) {
 		if (info->id_gpiod) {
 			ret = disable_irq_wake(info->id_irq);
 			if (ret)
 				return ret;
 		}
 		if (info->vbus_gpiod) {
 			ret = disable_irq_wake(info->vbus_irq);
 			if (ret) {
 				if (info->id_gpiod)
 					enable_irq_wake(info->id_irq);

 				return ret;
 			}
 		}
 	}

 	if (info->id_gpiod)
 		enable_irq(info->id_irq);
 	if (info->vbus_gpiod)
 		enable_irq(info->vbus_irq);

 	queue_delayed_work(system_power_efficient_wq,
 			   &info->wq_detcable, 0);

 	return ret;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
 			 usb_extcon_suspend, usb_extcon_resume);

 static const struct of_device_id usb_extcon_dt_match[] = {
 	{ .compatible = "linux,extcon-usb-gpio", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);

 static const struct platform_device_id usb_extcon_platform_ids[] = {
 	{ .name = "extcon-usb-gpio", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);

 static struct platform_driver usb_extcon_driver = {
 	.probe		= usb_extcon_probe,
 	.remove		= usb_extcon_remove,
 	.driver		= {
 		.name	= "extcon-usb-gpio",
 		.pm	= &usb_extcon_pm_ops,
 		.of_match_table = usb_extcon_dt_match,
 	},
 	.id_table = usb_extcon_platform_ids,
 };

 module_platform_driver(usb_extcon_driver);

 MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
 MODULE_DESCRIPTION("USB GPIO extcon driver");
 MODULE_LICENSE("GPL v2");
	/**
	* drivers/extcon/extcon-usb-gpio.c - USB GPIO extcon driver
	*
	* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
	* Author: Roger Quadros <rogerq@ti.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* 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/extcon.h>
	#include <linux/gpio.h>
	#include <linux/gpio/consumer.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_gpio.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/workqueue.h>
	#include <linux/pinctrl/consumer.h>

	#define USB_GPIO_DEBOUNCE_MS 20 /* ms */

	struct usb_extcon_info {
	struct device *dev;
	struct extcon_dev *edev;

	struct gpio_desc *id_gpiod;
	struct gpio_desc *vbus_gpiod;
	int id_irq;
	int vbus_irq;

	unsigned long debounce_jiffies;
	struct delayed_work wq_detcable;
	};

	static const unsigned int usb_extcon_cable[] = {
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_NONE,
	};

	/*
	* "USB" = VBUS and "USB-HOST" = !ID, so we have:
	* Both "USB" and "USB-HOST" can't be set as active at the
	* same time so if "USB-HOST" is active (i.e. ID is 0) we keep "USB" inactive
	* even if VBUS is on.
	*
	* State \| ID \| VBUS
	* ----------------------------------------
	* [1] USB \| H \| H
	* [2] none \| H \| L
	* [3] USB-HOST \| L \| H
	* [4] USB-HOST \| L \| L
	*
	* In case we have only one of these signals:
	* - VBUS only - we want to distinguish between [1] and [2], so ID is always 1.
	* - ID only - we want to distinguish between [1] and [4], so VBUS = ID.
	*/
	static void usb_extcon_detect_cable(struct work_struct *work)
	{
	int id, vbus;
	struct usb_extcon_info *info = container_of(to_delayed_work(work),
	struct usb_extcon_info,
	wq_detcable);

	/* check ID and VBUS and update cable state */
	id = info->id_gpiod ?
	gpiod_get_value_cansleep(info->id_gpiod) : 1;
	vbus = info->vbus_gpiod ?
	gpiod_get_value_cansleep(info->vbus_gpiod) : id;

	/* at first we clean states which are no longer active */
	if (id)
	extcon_set_state_sync(info->edev, EXTCON_USB_HOST, false);
	if (!vbus)
	extcon_set_state_sync(info->edev, EXTCON_USB, false);

	if (!id) {
	extcon_set_state_sync(info->edev, EXTCON_USB_HOST, true);
	} else {
	if (vbus)
	extcon_set_state_sync(info->edev, EXTCON_USB, true);
	}
	}

	static irqreturn_t usb_irq_handler(int irq, void *dev_id)
	{
	struct usb_extcon_info *info = dev_id;

	queue_delayed_work(system_power_efficient_wq, &info->wq_detcable,
	info->debounce_jiffies);

	return IRQ_HANDLED;
	}

	static int usb_extcon_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct usb_extcon_info *info;
	int ret;

	if (!np)
	return -EINVAL;

	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
	return -ENOMEM;

	info->dev = dev;
	info->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id", GPIOD_IN);
	info->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
	GPIOD_IN);

	if (!info->id_gpiod && !info->vbus_gpiod) {
	dev_err(dev, "failed to get gpios\n");
	return -ENODEV;
	}

	if (IS_ERR(info->id_gpiod))
	return PTR_ERR(info->id_gpiod);

	if (IS_ERR(info->vbus_gpiod))
	return PTR_ERR(info->vbus_gpiod);

	info->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
	if (IS_ERR(info->edev)) {
	dev_err(dev, "failed to allocate extcon device\n");
	return -ENOMEM;
	}

	ret = devm_extcon_dev_register(dev, info->edev);
	if (ret < 0) {
	dev_err(dev, "failed to register extcon device\n");
	return ret;
	}

	if (info->id_gpiod)
	ret = gpiod_set_debounce(info->id_gpiod,
	USB_GPIO_DEBOUNCE_MS * 1000);
	if (!ret && info->vbus_gpiod)
	ret = gpiod_set_debounce(info->vbus_gpiod,
	USB_GPIO_DEBOUNCE_MS * 1000);

	if (ret < 0)
	info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEBOUNCE_MS);

	INIT_DELAYED_WORK(&info->wq_detcable, usb_extcon_detect_cable);

	if (info->id_gpiod) {
	info->id_irq = gpiod_to_irq(info->id_gpiod);
	if (info->id_irq < 0) {
	dev_err(dev, "failed to get ID IRQ\n");
	return info->id_irq;
	}

	ret = devm_request_threaded_irq(dev, info->id_irq, NULL,
	usb_irq_handler,
	IRQF_TRIGGER_RISING \|
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	pdev->name, info);
	if (ret < 0) {
	dev_err(dev, "failed to request handler for ID IRQ\n");
	return ret;
	}
	}

	if (info->vbus_gpiod) {
	info->vbus_irq = gpiod_to_irq(info->vbus_gpiod);
	if (info->vbus_irq < 0) {
	dev_err(dev, "failed to get VBUS IRQ\n");
	return info->vbus_irq;
	}

	ret = devm_request_threaded_irq(dev, info->vbus_irq, NULL,
	usb_irq_handler,
	IRQF_TRIGGER_RISING \|
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	pdev->name, info);
	if (ret < 0) {
	dev_err(dev, "failed to request handler for VBUS IRQ\n");
	return ret;
	}
	}

	platform_set_drvdata(pdev, info);
	device_set_wakeup_capable(&pdev->dev, true);

	/* Perform initial detection */
	usb_extcon_detect_cable(&info->wq_detcable.work);

	return 0;
	}

	static int usb_extcon_remove(struct platform_device *pdev)
	{
	struct usb_extcon_info *info = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&info->wq_detcable);
	device_init_wakeup(&pdev->dev, false);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int usb_extcon_suspend(struct device *dev)
	{
	struct usb_extcon_info *info = dev_get_drvdata(dev);
	int ret = 0;

	if (device_may_wakeup(dev)) {
	if (info->id_gpiod) {
	ret = enable_irq_wake(info->id_irq);
	if (ret)
	return ret;
	}
	if (info->vbus_gpiod) {
	ret = enable_irq_wake(info->vbus_irq);
	if (ret) {
	if (info->id_gpiod)
	disable_irq_wake(info->id_irq);

	return ret;
	}
	}
	}

	/*
	* We don't want to process any IRQs after this point
	* as GPIOs used behind I2C subsystem might not be
	* accessible until resume completes. So disable IRQ.
	*/
	if (info->id_gpiod)
	disable_irq(info->id_irq);
	if (info->vbus_gpiod)
	disable_irq(info->vbus_irq);

	if (!device_may_wakeup(dev))
	pinctrl_pm_select_sleep_state(dev);

	return ret;
	}

	static int usb_extcon_resume(struct device *dev)
	{
	struct usb_extcon_info *info = dev_get_drvdata(dev);
	int ret = 0;

	if (!device_may_wakeup(dev))
	pinctrl_pm_select_default_state(dev);

	if (device_may_wakeup(dev)) {
	if (info->id_gpiod) {
	ret = disable_irq_wake(info->id_irq);
	if (ret)
	return ret;
	}
	if (info->vbus_gpiod) {
	ret = disable_irq_wake(info->vbus_irq);
	if (ret) {
	if (info->id_gpiod)
	enable_irq_wake(info->id_irq);

	return ret;
	}
	}
	}

	if (info->id_gpiod)
	enable_irq(info->id_irq);
	if (info->vbus_gpiod)
	enable_irq(info->vbus_irq);

	queue_delayed_work(system_power_efficient_wq,
	&info->wq_detcable, 0);

	return ret;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(usb_extcon_pm_ops,
	usb_extcon_suspend, usb_extcon_resume);

	static const struct of_device_id usb_extcon_dt_match[] = {
	{ .compatible = "linux,extcon-usb-gpio", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, usb_extcon_dt_match);

	static const struct platform_device_id usb_extcon_platform_ids[] = {
	{ .name = "extcon-usb-gpio", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(platform, usb_extcon_platform_ids);

	static struct platform_driver usb_extcon_driver = {
	.probe = usb_extcon_probe,
	.remove = usb_extcon_remove,
	.driver = {
	.name = "extcon-usb-gpio",
	.pm = &usb_extcon_pm_ops,
	.of_match_table = usb_extcon_dt_match,
	},
	.id_table = usb_extcon_platform_ids,
	};

	module_platform_driver(usb_extcon_driver);

	MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
	MODULE_DESCRIPTION("USB GPIO extcon driver");
	MODULE_LICENSE("GPL v2");