164 lines
4.3 KiB
C
164 lines
4.3 KiB
C
// 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/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.
|
|
* @irq: Interrupt line for the external connector.
|
|
* @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.
|
|
* @irq_flags: IRQ Flags (e.g., IRQF_TRIGGER_LOW).
|
|
* @check_on_resume: Boolean describing whether to check the state of gpio
|
|
* while resuming from sleep.
|
|
*/
|
|
struct gpio_extcon_data {
|
|
struct extcon_dev *edev;
|
|
int irq;
|
|
struct delayed_work work;
|
|
unsigned long debounce_jiffies;
|
|
struct gpio_desc *gpiod;
|
|
unsigned int extcon_id;
|
|
unsigned long debounce;
|
|
unsigned long irq_flags;
|
|
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;
|
|
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->irq_flags || 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);
|
|
data->irq = gpiod_to_irq(data->gpiod);
|
|
if (data->irq <= 0)
|
|
return data->irq;
|
|
|
|
/* 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;
|
|
|
|
INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
|
|
|
|
/*
|
|
* Request the interrupt of gpio to detect whether external connector
|
|
* is attached or detached.
|
|
*/
|
|
ret = devm_request_any_context_irq(dev, data->irq,
|
|
gpio_irq_handler, data->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;
|
|
}
|
|
|
|
static int gpio_extcon_remove(struct platform_device *pdev)
|
|
{
|
|
struct gpio_extcon_data *data = platform_get_drvdata(pdev);
|
|
|
|
cancel_delayed_work_sync(&data->work);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static 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,
|
|
.remove = gpio_extcon_remove,
|
|
.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");
|