/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* Driver for chargers which report their online status through a GPIO pin
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/power/gpio-charger.h>
struct gpio_charger {
const struct gpio_charger_platform_data *pdata;
unsigned int irq;
struct power_supply charger;
};
static irqreturn_t gpio_charger_irq(int irq, void *devid)
{
struct power_supply *charger = devid;
power_supply_changed(charger);
return IRQ_HANDLED;
}
static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
{
return container_of(psy, struct gpio_charger, charger);
}
static int gpio_charger_get_property(struct power_supply *psy,
enum power_supply_property psp, union power_supply_propval *val)
{
struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = gpio_get_value(pdata->gpio);
val->intval ^= pdata->gpio_active_low;
break;
default:
return -EINVAL;
}
return 0;
}
static enum power_supply_property gpio_charger_properties[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static int __devinit gpio_charger_probe(struct platform_device *pdev)
{
const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
struct gpio_charger *gpio_charger;
struct power_supply *charger;
int ret;
int irq;
if (!pdata) {
dev_err(&pdev->dev, "No platform data\n");
return -EINVAL;
}
if (!gpio_is_valid(pdata->gpio)) {
dev_err(&pdev->dev, "Invalid gpio pin\n");
return -EINVAL;
}
gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
if (!gpio_charger) {
dev_err(&pdev->dev, "Failed to alloc driver structure\n");
return -ENOMEM;
}
charger = &gpio_charger->charger;
charger->name = pdata->name ? pdata->name : "gpio-charger";
charger->type = pdata->type;
charger->properties = gpio_charger_properties;
charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
charger->get_property = gpio_charger_get_property;
charger->supplied_to = pdata->supplied_to;
charger->num_supplicants = pdata->num_supplicants;
ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
if (ret) {
dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
goto err_free;
}
ret = gpio_direction_input(pdata->gpio);
if (ret) {
dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
goto err_gpio_free;
}
irq = gpio_to_irq(pdata->gpio);
if (irq > 0) {
ret = request_irq(irq, gpio_charger_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
dev_name(&pdev->dev), charger);
if (ret)
dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
else
gpio_charger->irq = irq;
}
gpio_charger->pdata = pdata;
ret = power_supply_register(&pdev->dev, charger);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register power supply: %d\n", ret);
goto err_irq_free;
}
platform_set_drvdata(pdev, gpio_charger);
return 0;
err_irq_free:
if (gpio_charger->irq)
free_irq(gpio_charger->irq, charger);
err_gpio_free:
gpio_free(pdata->gpio);
err_free:
kfree(gpio_charger);
return ret;
}
static int __devexit gpio_charger_remove(struct platform_device *pdev)
{
struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
power_supply_unregister(&gpio_charger->charger);
if (gpio_charger->irq)
free_irq(gpio_charger->irq, &gpio_charger->charger);
gpio_free(gpio_charger->pdata->gpio);
platform_set_drvdata(pdev, NULL);
kfree(gpio_charger);
return 0;
}
static struct platform_driver gpio_charger_driver = {
.probe = gpio_charger_probe,
.remove = __devexit_p(gpio_charger_remove),
.driver = {
.name = "gpio-charger",
.owner = THIS_MODULE,
},
};
static int __init gpio_charger_init(void)
{
return platform_driver_register(&gpio_charger_driver);
}
module_init(gpio_charger_init);
static void __exit gpio_charger_exit(void)
{
platform_driver_unregister(&gpio_charger_driver);
}
module_exit(gpio_charger_exit);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-charger");
