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/**
* 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>
#define USB_GPIO_DEBOUNCE_MS 20 /* ms */
struct usb_extcon_info {
struct device *dev;
struct extcon_dev *edev;
struct gpio_desc *id_gpiod;
int id_irq;
unsigned long debounce_jiffies;
struct delayed_work wq_detcable;
};
static const unsigned int usb_extcon_cable[] = {
EXTCON_USB,
EXTCON_USB_HOST,
EXTCON_NONE,
};
static void usb_extcon_detect_cable(struct work_struct *work)
{
int id;
struct usb_extcon_info *info = container_of(to_delayed_work(work),
struct usb_extcon_info,
wq_detcable);
/* check ID and update cable state */
id = gpiod_get_value_cansleep(info->id_gpiod);
if (id) {
/*
* ID = 1 means USB HOST cable detached.
* As we don't have event for USB peripheral cable attached,
* we simulate USB peripheral attach here.
*/
extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, false);
extcon_set_cable_state_(info->edev, EXTCON_USB, true);
} else {
/*
* ID = 0 means USB HOST cable attached.
* As we don't have event for USB peripheral cable detached,
* we simulate USB peripheral detach here.
*/
extcon_set_cable_state_(info->edev, EXTCON_USB, false);
extcon_set_cable_state_(info->edev, EXTCON_USB_HOST, 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(&pdev->dev, "id", GPIOD_IN);
if (IS_ERR(info->id_gpiod)) {
dev_err(dev, "failed to get ID GPIO\n");
return PTR_ERR(info->id_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;
}
ret = gpiod_set_debounce(info->id_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);
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;
}
platform_set_drvdata(pdev, info);
device_init_wakeup(dev, 1);
/* 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);
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)) {
ret = enable_irq_wake(info->id_irq);
if (ret)
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.
*/
disable_irq(info->id_irq);
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)) {
ret = disable_irq_wake(info->id_irq);
if (ret)
return ret;
}
enable_irq(info->id_irq);
if (!device_may_wakeup(dev))
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 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,
},
};
module_platform_driver(usb_extcon_driver);
MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
MODULE_DESCRIPTION("USB GPIO extcon driver");
MODULE_LICENSE("GPL v2");
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