linux-imx

/**

 * 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-provider.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