Commit be48308a authored by MyungJoo Ham's avatar MyungJoo Ham Committed by Greg Kroah-Hartman

Extcon: support generic GPIO extcon driver

The generic GPIO extcon driver (an external connector device based on
GPIO control) and imported from Android kernel.

switch: switch class and GPIO drivers. (splitted)
Author: Mike Lockwood <lockwood@android.com>

switch: gpio: Don't call request_irq with interrupts disabled
Author: Arve Hjønnevåg <arve@android.com>

switch_gpio: Add missing #include <linux/interrupt.h>
Author: Mike Lockwood <lockwood@android.com>
Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>

--
Changed from v7:
- Style updates mentioned by Stephen Boyd and Mark Brown
Changed from v5:
- Splitted at v5 from the main extcon patch.
- Added debounce time for irq handlers.
- Use request_any_context_irq instead of request_irq
- User needs to specify irq flags for GPIO interrupts (was fixed to
IRQF_TRIGGER_LOW before)
- Use module_platform_driver().
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent de55d871
......@@ -14,4 +14,11 @@ if EXTCON
comment "Extcon Device Drivers"
config EXTCON_GPIO
tristate "GPIO extcon support"
depends on GENERIC_GPIO
help
Say Y here to enable GPIO based extcon support. Note that GPIO
extcon supports single state per extcon instance.
endif # MULTISTATE_SWITCH
......@@ -3,3 +3,4 @@
#
obj-$(CONFIG_EXTCON) += extcon_class.o
obj-$(CONFIG_EXTCON_GPIO) += extcon_gpio.o
/*
* drivers/extcon/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)
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/extcon.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/extcon.h>
#include <linux/extcon/extcon_gpio.h>
struct gpio_extcon_data {
struct extcon_dev edev;
unsigned gpio;
const char *state_on;
const char *state_off;
int irq;
struct delayed_work work;
unsigned long debounce_jiffies;
};
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 = gpio_get_value(data->gpio);
extcon_set_state(&data->edev, state);
}
static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
{
struct gpio_extcon_data *extcon_data = dev_id;
schedule_delayed_work(&extcon_data->work,
extcon_data->debounce_jiffies);
return IRQ_HANDLED;
}
static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
{
struct gpio_extcon_data *extcon_data =
container_of(edev, struct gpio_extcon_data, edev);
const char *state;
if (extcon_get_state(edev))
state = extcon_data->state_on;
else
state = extcon_data->state_off;
if (state)
return sprintf(buf, "%s\n", state);
return -EINVAL;
}
static int __devinit gpio_extcon_probe(struct platform_device *pdev)
{
struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
struct gpio_extcon_data *extcon_data;
int ret = 0;
if (!pdata)
return -EBUSY;
if (!pdata->irq_flags) {
dev_err(&pdev->dev, "IRQ flag is not specified.\n");
return -EINVAL;
}
extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
GFP_KERNEL);
if (!extcon_data)
return -ENOMEM;
extcon_data->edev.name = pdata->name;
extcon_data->gpio = pdata->gpio;
extcon_data->state_on = pdata->state_on;
extcon_data->state_off = pdata->state_off;
if (pdata->state_on && pdata->state_off)
extcon_data->edev.print_state = extcon_gpio_print_state;
extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
if (ret < 0)
goto err_extcon_dev_register;
ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name);
if (ret < 0)
goto err_request_gpio;
INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
extcon_data->irq = gpio_to_irq(extcon_data->gpio);
if (extcon_data->irq < 0) {
ret = extcon_data->irq;
goto err_detect_irq_num_failed;
}
ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
pdata->irq_flags, pdev->name,
extcon_data);
if (ret < 0)
goto err_request_irq;
/* Perform initial detection */
gpio_extcon_work(&extcon_data->work.work);
return 0;
err_request_irq:
err_detect_irq_num_failed:
gpio_free(extcon_data->gpio);
err_request_gpio:
extcon_dev_unregister(&extcon_data->edev);
err_extcon_dev_register:
devm_kfree(&pdev->dev, extcon_data);
return ret;
}
static int __devexit gpio_extcon_remove(struct platform_device *pdev)
{
struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&extcon_data->work);
gpio_free(extcon_data->gpio);
extcon_dev_unregister(&extcon_data->edev);
devm_kfree(&pdev->dev, extcon_data);
return 0;
}
static struct platform_driver gpio_extcon = {
.probe = gpio_extcon_probe,
.remove = __devexit_p(gpio_extcon_remove),
.driver = {
.name = "extcon-gpio",
.owner = THIS_MODULE,
},
};
module_platform_driver(gpio_extcon);
MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("GPIO extcon driver");
MODULE_LICENSE("GPL");
/*
* External connector (extcon) class generic GPIO driver
*
* Copyright (C) 2012 Samsung Electronics
* Author: MyungJoo Ham <myungjoo.ham@samsung.com>
*
* based on switch class driver
* Copyright (C) 2008 Google, Inc.
* Author: Mike Lockwood <lockwood@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#ifndef __EXTCON_GPIO_H__
#define __EXTCON_GPIO_H__ __FILE__
#include <linux/extcon.h>
/**
* struct gpio_extcon_platform_data - A simple GPIO-controlled extcon device.
* @name The name of this GPIO extcon device.
* @gpio Corresponding GPIO.
* @debounce Debounce time for GPIO IRQ in ms.
* @irq_flags IRQ Flags (e.g., IRQF_TRIGGER_LOW).
* @state_on print_state is overriden with state_on if attached. If Null,
* default method of extcon class is used.
* @state_off print_state is overriden with state_on if dettached. If Null,
* default method of extcon class is used.
*
* Note that in order for state_on or state_off to be valid, both state_on
* and state_off should be not NULL. If at least one of them is NULL,
* the print_state is not overriden.
*/
struct gpio_extcon_platform_data {
const char *name;
unsigned gpio;
unsigned long debounce;
unsigned long irq_flags;
/* if NULL, "0" or "1" will be printed */
const char *state_on;
const char *state_off;
};
#endif /* __EXTCON_GPIO_H__ */
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