linux/drivers/extcon/extcon-usb-gpio.c
Roger Quadros 92b7cb5dc8 extcon: palmas: Support GPIO based USB ID detection
Some palmas based chip variants do not have OTG based ID logic.
For these variants we rely on GPIO based USB ID detection.

These chips do have VBUS comparator for VBUS detection so we
continue to use the old way of detecting VBUS.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2015-08-10 21:26:25 +09:00

224 lines
5.4 KiB
C

/**
* 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);
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");