linux/drivers/extcon/extcon-gpio.c
Linus Walleij 8bc4810b43 extcon: gpio: Request reasonable interrupts
The only thing that makes sense is to request a falling edge interrupt
if the line is active low and a rising edge interrupt if the line is
active high, so just do that and get rid of the assignment from
platform data. The GPIO descriptor knows if the line is active high
or low.

Also make irq a local variable in probe(), it's not used anywhere else.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[cw00.choi: Fix build error of data->irq_flags]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2019-07-24 19:20:19 +09:00

173 lines
4.5 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.
* @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.
* @check_on_resume: Boolean describing whether to check the state of gpio
* while resuming from sleep.
*/
struct gpio_extcon_data {
struct extcon_dev *edev;
struct delayed_work work;
unsigned long debounce_jiffies;
struct gpio_desc *gpiod;
unsigned int extcon_id;
unsigned long debounce;
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;
unsigned long irq_flags;
int irq;
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->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);
irq = gpiod_to_irq(data->gpiod);
if (irq <= 0)
return irq;
/*
* It is unlikely that this is an acknowledged interrupt that goes
* away after handling, what we are looking for are falling edges
* if the signal is active low, and rising edges if the signal is
* active high.
*/
if (gpiod_is_active_low(data->gpiod))
irq_flags = IRQF_TRIGGER_FALLING;
else
irq_flags = IRQF_TRIGGER_RISING;
/* 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, irq,
gpio_irq_handler, 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");