424 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			424 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /*
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|  * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
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|  *
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|  * Copyright (C) 2011 Samsung Electronics
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|  * MyungJoo Ham <myungjoo.ham@samsung.com>
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|  */
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| 
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| #include <linux/gpio/consumer.h>
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| #include <linux/interrupt.h>
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| #include <linux/module.h>
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| #include <linux/of.h>
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| #include <linux/of_device.h>
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| #include <linux/slab.h>
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| #include <linux/power_supply.h>
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| #include <linux/platform_device.h>
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| 
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| struct max8903_data {
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| 	struct device *dev;
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| 	struct power_supply *psy;
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| 	struct power_supply_desc psy_desc;
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| 	/*
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| 	 * GPIOs
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| 	 * chg, flt, dcm and usus are optional.
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| 	 * dok or uok must be present.
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| 	 * If dok is present, cen must be present.
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| 	 */
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| 	struct gpio_desc *cen; /* Charger Enable input */
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| 	struct gpio_desc *dok; /* DC (Adapter) Power OK output */
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| 	struct gpio_desc *uok; /* USB Power OK output */
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| 	struct gpio_desc *chg; /* Charger status output */
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| 	struct gpio_desc *flt; /* Fault output */
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| 	struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */
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| 	struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */
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| 	bool fault;
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| 	bool usb_in;
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| 	bool ta_in;
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| };
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| 
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| static enum power_supply_property max8903_charger_props[] = {
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| 	POWER_SUPPLY_PROP_STATUS, /* Charger status output */
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| 	POWER_SUPPLY_PROP_ONLINE, /* External power source */
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| 	POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
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| };
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| 
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| static int max8903_get_property(struct power_supply *psy,
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| 		enum power_supply_property psp,
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| 		union power_supply_propval *val)
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| {
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| 	struct max8903_data *data = power_supply_get_drvdata(psy);
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| 
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| 	switch (psp) {
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| 	case POWER_SUPPLY_PROP_STATUS:
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| 		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
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| 		if (data->chg) {
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| 			if (gpiod_get_value(data->chg))
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| 				/* CHG asserted */
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| 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
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| 			else if (data->usb_in || data->ta_in)
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| 				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
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| 			else
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| 				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
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| 		}
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| 		break;
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| 	case POWER_SUPPLY_PROP_ONLINE:
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| 		val->intval = 0;
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| 		if (data->usb_in || data->ta_in)
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| 			val->intval = 1;
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| 		break;
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| 	case POWER_SUPPLY_PROP_HEALTH:
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| 		val->intval = POWER_SUPPLY_HEALTH_GOOD;
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| 		if (data->fault)
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| 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
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| 		break;
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| 	default:
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| 		return -EINVAL;
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static irqreturn_t max8903_dcin(int irq, void *_data)
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| {
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| 	struct max8903_data *data = _data;
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| 	bool ta_in;
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| 	enum power_supply_type old_type;
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| 
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| 	/*
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| 	 * This means the line is asserted.
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| 	 *
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| 	 * The signal is active low, but the inversion is handled in the GPIO
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| 	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
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| 	 * tree.
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| 	 */
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| 	ta_in = gpiod_get_value(data->dok);
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| 
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| 	if (ta_in == data->ta_in)
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| 		return IRQ_HANDLED;
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| 
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| 	data->ta_in = ta_in;
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| 
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| 	/* Set Current-Limit-Mode 1:DC 0:USB */
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| 	if (data->dcm)
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| 		gpiod_set_value(data->dcm, ta_in);
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| 
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| 	/* Charger Enable / Disable */
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| 	if (data->cen) {
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| 		int val;
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| 
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| 		if (ta_in)
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| 			/* Certainly enable if DOK is asserted */
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| 			val = 1;
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| 		else if (data->usb_in)
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| 			/* Enable if the USB charger is enabled */
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| 			val = 1;
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| 		else
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| 			/* Else default-disable */
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| 			val = 0;
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| 
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| 		gpiod_set_value(data->cen, val);
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| 	}
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| 
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| 	dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
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| 			"Connected" : "Disconnected");
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| 
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| 	old_type = data->psy_desc.type;
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| 
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| 	if (data->ta_in)
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
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| 	else if (data->usb_in)
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
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| 	else
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
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| 
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| 	if (old_type != data->psy_desc.type)
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| 		power_supply_changed(data->psy);
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static irqreturn_t max8903_usbin(int irq, void *_data)
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| {
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| 	struct max8903_data *data = _data;
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| 	bool usb_in;
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| 	enum power_supply_type old_type;
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| 
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| 	/*
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| 	 * This means the line is asserted.
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| 	 *
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| 	 * The signal is active low, but the inversion is handled in the GPIO
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| 	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
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| 	 * tree.
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| 	 */
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| 	usb_in = gpiod_get_value(data->uok);
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| 
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| 	if (usb_in == data->usb_in)
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| 		return IRQ_HANDLED;
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| 
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| 	data->usb_in = usb_in;
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| 
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| 	/* Do not touch Current-Limit-Mode */
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| 
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| 	/* Charger Enable / Disable */
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| 	if (data->cen) {
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| 		int val;
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| 
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| 		if (usb_in)
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| 			/* Certainly enable if UOK is asserted */
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| 			val = 1;
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| 		else if (data->ta_in)
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| 			/* Enable if the DC charger is enabled */
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| 			val = 1;
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| 		else
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| 			/* Else default-disable */
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| 			val = 0;
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| 
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| 		gpiod_set_value(data->cen, val);
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| 	}
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| 
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| 	dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
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| 			"Connected" : "Disconnected");
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| 
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| 	old_type = data->psy_desc.type;
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| 
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| 	if (data->ta_in)
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
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| 	else if (data->usb_in)
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
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| 	else
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| 		data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
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| 
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| 	if (old_type != data->psy_desc.type)
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| 		power_supply_changed(data->psy);
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static irqreturn_t max8903_fault(int irq, void *_data)
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| {
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| 	struct max8903_data *data = _data;
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| 	bool fault;
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| 
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| 	/*
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| 	 * This means the line is asserted.
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| 	 *
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| 	 * The signal is active low, but the inversion is handled in the GPIO
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| 	 * library as the line should be flagged GPIO_ACTIVE_LOW in the device
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| 	 * tree.
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| 	 */
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| 	fault = gpiod_get_value(data->flt);
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| 
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| 	if (fault == data->fault)
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| 		return IRQ_HANDLED;
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| 
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| 	data->fault = fault;
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| 
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| 	if (fault)
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| 		dev_err(data->dev, "Charger suffers a fault and stops.\n");
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| 	else
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| 		dev_err(data->dev, "Charger recovered from a fault.\n");
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| static int max8903_setup_gpios(struct platform_device *pdev)
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| {
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| 	struct max8903_data *data = platform_get_drvdata(pdev);
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| 	struct device *dev = &pdev->dev;
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| 	bool ta_in = false;
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| 	bool usb_in = false;
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| 	enum gpiod_flags flags;
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| 
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| 	data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN);
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| 	if (IS_ERR(data->dok))
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| 		return dev_err_probe(dev, PTR_ERR(data->dok),
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| 				     "failed to get DOK GPIO");
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| 	if (data->dok) {
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| 		gpiod_set_consumer_name(data->dok, data->psy_desc.name);
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| 		/*
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| 		 * The DC OK is pulled up to 1 and goes low when a charger
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| 		 * is plugged in (active low) but in the device tree the
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| 		 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
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| 		 * here if the DC charger is plugged in.
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| 		 */
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| 		ta_in = gpiod_get_value(data->dok);
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| 	}
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| 
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| 	data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN);
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| 	if (IS_ERR(data->uok))
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| 		return dev_err_probe(dev, PTR_ERR(data->uok),
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| 				     "failed to get UOK GPIO");
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| 	if (data->uok) {
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| 		gpiod_set_consumer_name(data->uok, data->psy_desc.name);
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| 		/*
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| 		 * The USB OK is pulled up to 1 and goes low when a USB charger
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| 		 * is plugged in (active low) but in the device tree the
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| 		 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
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| 		 * here if the USB charger is plugged in.
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| 		 */
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| 		usb_in = gpiod_get_value(data->uok);
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| 	}
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| 
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| 	/* Either DC OK or USB OK must be provided */
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| 	if (!data->dok && !data->uok) {
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| 		dev_err(dev, "no valid power source\n");
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| 		return -EINVAL;
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| 	}
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| 
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| 	/*
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| 	 * If either charger is already connected at this point,
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| 	 * assert the CEN line and enable charging from the start.
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| 	 *
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| 	 * The line is active low but also marked with GPIO_ACTIVE_LOW
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| 	 * in the device tree, so when we assert the line with
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| 	 * GPIOD_OUT_HIGH the line will be driven low.
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| 	 */
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| 	flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
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| 	/*
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| 	 * If DC OK is provided, Charger Enable CEN is compulsory
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| 	 * so this is not optional here.
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| 	 */
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| 	data->cen = devm_gpiod_get(dev, "cen", flags);
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| 	if (IS_ERR(data->cen))
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| 		return dev_err_probe(dev, PTR_ERR(data->cen),
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| 				     "failed to get CEN GPIO");
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| 	gpiod_set_consumer_name(data->cen, data->psy_desc.name);
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| 
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| 	/*
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| 	 * If the DC charger is connected, then select it.
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| 	 *
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| 	 * The DCM line should be marked GPIO_ACTIVE_HIGH in the
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| 	 * device tree. Driving it high will enable the DC charger
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| 	 * input over the USB charger input.
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| 	 */
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| 	flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
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| 	data->dcm = devm_gpiod_get_optional(dev, "dcm", flags);
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| 	if (IS_ERR(data->dcm))
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| 		return dev_err_probe(dev, PTR_ERR(data->dcm),
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| 				     "failed to get DCM GPIO");
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| 	gpiod_set_consumer_name(data->dcm, data->psy_desc.name);
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| 
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| 	data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN);
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| 	if (IS_ERR(data->chg))
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| 		return dev_err_probe(dev, PTR_ERR(data->chg),
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| 				     "failed to get CHG GPIO");
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| 	gpiod_set_consumer_name(data->chg, data->psy_desc.name);
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| 
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| 	data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN);
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| 	if (IS_ERR(data->flt))
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| 		return dev_err_probe(dev, PTR_ERR(data->flt),
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| 				     "failed to get FLT GPIO");
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| 	gpiod_set_consumer_name(data->flt, data->psy_desc.name);
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| 
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| 	data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN);
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| 	if (IS_ERR(data->usus))
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| 		return dev_err_probe(dev, PTR_ERR(data->usus),
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| 				     "failed to get USUS GPIO");
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| 	gpiod_set_consumer_name(data->usus, data->psy_desc.name);
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| 
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| 	data->fault = false;
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| 	data->ta_in = ta_in;
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| 	data->usb_in = usb_in;
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| 
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| 	return 0;
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| }
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| 
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| static int max8903_probe(struct platform_device *pdev)
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| {
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| 	struct max8903_data *data;
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| 	struct device *dev = &pdev->dev;
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| 	struct power_supply_config psy_cfg = {};
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| 	int ret = 0;
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| 
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| 	data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
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| 	if (!data)
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| 		return -ENOMEM;
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| 
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| 	data->dev = dev;
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| 	platform_set_drvdata(pdev, data);
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| 
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| 	ret = max8903_setup_gpios(pdev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	data->psy_desc.name = "max8903_charger";
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| 	data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
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| 			((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
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| 			 POWER_SUPPLY_TYPE_BATTERY);
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| 	data->psy_desc.get_property = max8903_get_property;
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| 	data->psy_desc.properties = max8903_charger_props;
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| 	data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
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| 
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| 	psy_cfg.of_node = dev->of_node;
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| 	psy_cfg.drv_data = data;
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| 
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| 	data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
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| 	if (IS_ERR(data->psy)) {
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| 		dev_err(dev, "failed: power supply register.\n");
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| 		return PTR_ERR(data->psy);
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| 	}
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| 
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| 	if (data->dok) {
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| 		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok),
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| 					NULL, max8903_dcin,
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| 					IRQF_TRIGGER_FALLING |
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| 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
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| 					"MAX8903 DC IN", data);
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| 		if (ret) {
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| 			dev_err(dev, "Cannot request irq %d for DC (%d)\n",
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| 					gpiod_to_irq(data->dok), ret);
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| 			return ret;
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| 		}
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| 	}
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| 
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| 	if (data->uok) {
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| 		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok),
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| 					NULL, max8903_usbin,
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| 					IRQF_TRIGGER_FALLING |
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| 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
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| 					"MAX8903 USB IN", data);
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| 		if (ret) {
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| 			dev_err(dev, "Cannot request irq %d for USB (%d)\n",
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| 					gpiod_to_irq(data->uok), ret);
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| 			return ret;
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| 		}
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| 	}
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| 
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| 	if (data->flt) {
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| 		ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt),
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| 					NULL, max8903_fault,
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| 					IRQF_TRIGGER_FALLING |
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| 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
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| 					"MAX8903 Fault", data);
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| 		if (ret) {
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| 			dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
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| 					gpiod_to_irq(data->flt), ret);
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| 			return ret;
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| 		}
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static const struct of_device_id max8903_match_ids[] = {
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| 	{ .compatible = "maxim,max8903", },
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| 	{ /* sentinel */ }
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| };
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| MODULE_DEVICE_TABLE(of, max8903_match_ids);
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| 
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| static struct platform_driver max8903_driver = {
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| 	.probe	= max8903_probe,
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| 	.driver = {
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| 		.name	= "max8903-charger",
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| 		.of_match_table = max8903_match_ids
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| 	},
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| };
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| 
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| module_platform_driver(max8903_driver);
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| 
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| MODULE_LICENSE("GPL");
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| MODULE_DESCRIPTION("MAX8903 Charger Driver");
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| MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
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| MODULE_ALIAS("platform:max8903-charger");
 |