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/*
* 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> /* For legacy platform data */
#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/of.h>
#include <linux/gpio/consumer.h>
#include <linux/power/gpio-charger.h>
struct gpio_charger {
const struct gpio_charger_platform_data *pdata;
unsigned int irq;
bool wakeup_enabled;
struct power_supply *charger;
struct power_supply_desc charger_desc;
struct gpio_desc *gpiod;
};
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 power_supply_get_drvdata(psy);
}
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);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
break;
default:
return -EINVAL;
}
return 0;
}
static enum power_supply_property gpio_charger_properties[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static
struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
{
struct device_node *np = dev->of_node;
struct gpio_charger_platform_data *pdata;
const char *chargetype;
int ret;
if (!np)
return ERR_PTR(-ENOENT);
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->name = np->name;
pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
ret = of_property_read_string(np, "charger-type", &chargetype);
if (ret >= 0) {
if (!strncmp("unknown", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
else if (!strncmp("battery", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_BATTERY;
else if (!strncmp("ups", chargetype, 3))
pdata->type = POWER_SUPPLY_TYPE_UPS;
else if (!strncmp("mains", chargetype, 5))
pdata->type = POWER_SUPPLY_TYPE_MAINS;
else if (!strncmp("usb-sdp", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_USB;
else if (!strncmp("usb-dcp", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
else if (!strncmp("usb-cdp", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
else if (!strncmp("usb-aca", chargetype, 7))
pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
else
dev_warn(dev, "unknown charger type %s\n", chargetype);
}
return pdata;
}
static int gpio_charger_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct gpio_charger_platform_data *pdata = dev->platform_data;
struct power_supply_config psy_cfg = {};
struct gpio_charger *gpio_charger;
struct power_supply_desc *charger_desc;
unsigned long flags;
int irq, ret;
if (!pdata) {
pdata = gpio_charger_parse_dt(dev);
if (IS_ERR(pdata)) {
ret = PTR_ERR(pdata);
if (ret != -EPROBE_DEFER)
dev_err(dev, "No platform data\n");
return ret;
}
}
gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
if (!gpio_charger)
return -ENOMEM;
/*
* This will fetch a GPIO descriptor from device tree, ACPI or
* boardfile descriptor tables. It's good to try this first.
*/
gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);
/*
* If this fails and we're not using device tree, try the
* legacy platform data method.
*/
if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) {
/* Non-DT: use legacy GPIO numbers */
if (!gpio_is_valid(pdata->gpio)) {
dev_err(dev, "Invalid gpio pin in pdata\n");
return -EINVAL;
}
flags = GPIOF_IN;
if (pdata->gpio_active_low)
flags |= GPIOF_ACTIVE_LOW;
ret = devm_gpio_request_one(dev, pdata->gpio, flags,
dev_name(dev));
if (ret) {
dev_err(dev, "Failed to request gpio pin: %d\n", ret);
return ret;
}
/* Then convert this to gpiod for now */
gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
} else if (IS_ERR(gpio_charger->gpiod)) {
/* Just try again if this happens */
if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_err(dev, "error getting GPIO descriptor\n");
return PTR_ERR(gpio_charger->gpiod);
}
charger_desc = &gpio_charger->charger_desc;
charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
charger_desc->type = pdata->type;
charger_desc->properties = gpio_charger_properties;
charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
charger_desc->get_property = gpio_charger_get_property;
psy_cfg.supplied_to = pdata->supplied_to;
psy_cfg.num_supplicants = pdata->num_supplicants;
psy_cfg.of_node = dev->of_node;
psy_cfg.drv_data = gpio_charger;
gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
&psy_cfg);
if (IS_ERR(gpio_charger->charger)) {
ret = PTR_ERR(gpio_charger->charger);
dev_err(dev, "Failed to register power supply: %d\n", ret);
return ret;
}
irq = gpiod_to_irq(gpio_charger->gpiod);
if (irq > 0) {
ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
dev_name(dev), gpio_charger->charger);
if (ret < 0)
dev_warn(dev, "Failed to request irq: %d\n", ret);
else
gpio_charger->irq = irq;
}
platform_set_drvdata(pdev, gpio_charger);
device_init_wakeup(dev, 1);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int gpio_charger_suspend(struct device *dev)
{
struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
gpio_charger->wakeup_enabled =
!enable_irq_wake(gpio_charger->irq);
return 0;
}
static int gpio_charger_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
disable_irq_wake(gpio_charger->irq);
power_supply_changed(gpio_charger->charger);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
gpio_charger_suspend, gpio_charger_resume);
static const struct of_device_id gpio_charger_match[] = {
{ .compatible = "gpio-charger" },
{ }
};
MODULE_DEVICE_TABLE(of, gpio_charger_match);
static struct platform_driver gpio_charger_driver = {
.probe = gpio_charger_probe,
.driver = {
.name = "gpio-charger",
.pm = &gpio_charger_pm_ops,
.of_match_table = gpio_charger_match,
},
};
module_platform_driver(gpio_charger_driver);
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");
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