249 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			249 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
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 *  Driver for chargers which report their online status through a GPIO pin
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 *
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 *  This program is free software; you can redistribute it and/or modify it
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 *  under  the terms of the GNU General  Public License as published by the
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 *  Free Software Foundation;  either version 2 of the License, or (at your
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 *  option) any later version.
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 *
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 *  You should have received a copy of the GNU General Public License along
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 *  with this program; if not, write to the Free Software Foundation, Inc.,
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 *  675 Mass Ave, Cambridge, MA 02139, USA.
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 *
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 */
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#include <linux/device.h>
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#include <linux/gpio.h> /* For legacy platform data */
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/power_supply.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/gpio/consumer.h>
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#include <linux/power/gpio-charger.h>
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struct gpio_charger {
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	unsigned int irq;
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	bool wakeup_enabled;
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	struct power_supply *charger;
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	struct power_supply_desc charger_desc;
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	struct gpio_desc *gpiod;
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};
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static irqreturn_t gpio_charger_irq(int irq, void *devid)
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{
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	struct power_supply *charger = devid;
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	power_supply_changed(charger);
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	return IRQ_HANDLED;
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}
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static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
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{
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	return power_supply_get_drvdata(psy);
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}
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static int gpio_charger_get_property(struct power_supply *psy,
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		enum power_supply_property psp, union power_supply_propval *val)
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{
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	struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
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	switch (psp) {
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	case POWER_SUPPLY_PROP_ONLINE:
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		val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
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		break;
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	default:
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		return -EINVAL;
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	}
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	return 0;
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}
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static enum power_supply_type gpio_charger_get_type(struct device *dev)
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{
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	const char *chargetype;
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	if (!device_property_read_string(dev, "charger-type", &chargetype)) {
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		if (!strcmp("unknown", chargetype))
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			return POWER_SUPPLY_TYPE_UNKNOWN;
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		if (!strcmp("battery", chargetype))
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			return POWER_SUPPLY_TYPE_BATTERY;
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		if (!strcmp("ups", chargetype))
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			return POWER_SUPPLY_TYPE_UPS;
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		if (!strcmp("mains", chargetype))
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			return POWER_SUPPLY_TYPE_MAINS;
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		if (!strcmp("usb-sdp", chargetype))
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			return POWER_SUPPLY_TYPE_USB;
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		if (!strcmp("usb-dcp", chargetype))
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			return POWER_SUPPLY_TYPE_USB_DCP;
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		if (!strcmp("usb-cdp", chargetype))
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			return POWER_SUPPLY_TYPE_USB_CDP;
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		if (!strcmp("usb-aca", chargetype))
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			return POWER_SUPPLY_TYPE_USB_ACA;
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	}
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	dev_warn(dev, "unknown charger type %s\n", chargetype);
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	return POWER_SUPPLY_TYPE_UNKNOWN;
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}
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static enum power_supply_property gpio_charger_properties[] = {
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	POWER_SUPPLY_PROP_ONLINE,
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};
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static int gpio_charger_probe(struct platform_device *pdev)
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{
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	struct device *dev = &pdev->dev;
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	const struct gpio_charger_platform_data *pdata = dev->platform_data;
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	struct power_supply_config psy_cfg = {};
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	struct gpio_charger *gpio_charger;
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	struct power_supply_desc *charger_desc;
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	unsigned long flags;
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	int irq, ret;
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	if (!pdata && !dev->of_node) {
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		dev_err(dev, "No platform data\n");
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		return -ENOENT;
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	}
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	gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
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	if (!gpio_charger)
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		return -ENOMEM;
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	/*
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	 * This will fetch a GPIO descriptor from device tree, ACPI or
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	 * boardfile descriptor tables. It's good to try this first.
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	 */
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	gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);
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	/*
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	 * If this fails and we're not using device tree, try the
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	 * legacy platform data method.
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	 */
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	if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) {
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		/* Non-DT: use legacy GPIO numbers */
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		if (!gpio_is_valid(pdata->gpio)) {
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			dev_err(dev, "Invalid gpio pin in pdata\n");
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			return -EINVAL;
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		}
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		flags = GPIOF_IN;
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		if (pdata->gpio_active_low)
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			flags |= GPIOF_ACTIVE_LOW;
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		ret = devm_gpio_request_one(dev, pdata->gpio, flags,
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					    dev_name(dev));
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		if (ret) {
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			dev_err(dev, "Failed to request gpio pin: %d\n", ret);
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			return ret;
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		}
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		/* Then convert this to gpiod for now */
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		gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
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	} else if (IS_ERR(gpio_charger->gpiod)) {
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		/* Just try again if this happens */
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		if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
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			return -EPROBE_DEFER;
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		dev_err(dev, "error getting GPIO descriptor\n");
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		return PTR_ERR(gpio_charger->gpiod);
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	}
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	charger_desc = &gpio_charger->charger_desc;
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	charger_desc->properties = gpio_charger_properties;
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	charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
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	charger_desc->get_property = gpio_charger_get_property;
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	psy_cfg.of_node = dev->of_node;
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	psy_cfg.drv_data = gpio_charger;
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	if (pdata) {
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		charger_desc->name = pdata->name;
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		charger_desc->type = pdata->type;
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		psy_cfg.supplied_to = pdata->supplied_to;
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		psy_cfg.num_supplicants = pdata->num_supplicants;
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	} else {
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		charger_desc->name = dev->of_node->name;
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		charger_desc->type = gpio_charger_get_type(dev);
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	}
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	if (!charger_desc->name)
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		charger_desc->name = pdev->name;
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	gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
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							   &psy_cfg);
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	if (IS_ERR(gpio_charger->charger)) {
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		ret = PTR_ERR(gpio_charger->charger);
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		dev_err(dev, "Failed to register power supply: %d\n", ret);
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		return ret;
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	}
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	irq = gpiod_to_irq(gpio_charger->gpiod);
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	if (irq > 0) {
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		ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
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				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
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				dev_name(dev), gpio_charger->charger);
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		if (ret < 0)
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			dev_warn(dev, "Failed to request irq: %d\n", ret);
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		else
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			gpio_charger->irq = irq;
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	}
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	platform_set_drvdata(pdev, gpio_charger);
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	device_init_wakeup(dev, 1);
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	return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int gpio_charger_suspend(struct device *dev)
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{
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	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
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	if (device_may_wakeup(dev))
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		gpio_charger->wakeup_enabled =
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			!enable_irq_wake(gpio_charger->irq);
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	return 0;
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}
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static int gpio_charger_resume(struct device *dev)
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{
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	struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
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	if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
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		disable_irq_wake(gpio_charger->irq);
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	power_supply_changed(gpio_charger->charger);
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	return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
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		gpio_charger_suspend, gpio_charger_resume);
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static const struct of_device_id gpio_charger_match[] = {
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	{ .compatible = "gpio-charger" },
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	{ }
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};
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MODULE_DEVICE_TABLE(of, gpio_charger_match);
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static struct platform_driver gpio_charger_driver = {
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	.probe = gpio_charger_probe,
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	.driver = {
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		.name = "gpio-charger",
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		.pm = &gpio_charger_pm_ops,
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		.of_match_table = gpio_charger_match,
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	},
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};
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module_platform_driver(gpio_charger_driver);
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:gpio-charger");
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