256 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			256 lines
		
	
	
		
			6.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /*
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|  * Copyright (c) 2016, Prodys S.L.
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|  *
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|  * This adds support for sbs-charger compilant chips as defined here:
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|  * http://sbs-forum.org/specs/sbc110.pdf
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|  *
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|  * Implemetation based on sbs-battery.c
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|  */
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| 
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| #include <linux/init.h>
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| #include <linux/module.h>
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| #include <linux/kernel.h>
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| #include <linux/err.h>
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| #include <linux/power_supply.h>
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| #include <linux/i2c.h>
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| #include <linux/slab.h>
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| #include <linux/interrupt.h>
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| #include <linux/regmap.h>
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| #include <linux/bitops.h>
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| #include <linux/devm-helpers.h>
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| 
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| #define SBS_CHARGER_REG_SPEC_INFO		0x11
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| #define SBS_CHARGER_REG_STATUS			0x13
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| #define SBS_CHARGER_REG_ALARM_WARNING		0x16
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| 
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| #define SBS_CHARGER_STATUS_CHARGE_INHIBITED	BIT(0)
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| #define SBS_CHARGER_STATUS_RES_COLD		BIT(9)
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| #define SBS_CHARGER_STATUS_RES_HOT		BIT(10)
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| #define SBS_CHARGER_STATUS_BATTERY_PRESENT	BIT(14)
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| #define SBS_CHARGER_STATUS_AC_PRESENT		BIT(15)
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| 
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| #define SBS_CHARGER_POLL_TIME			500
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| 
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| struct sbs_info {
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| 	struct i2c_client		*client;
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| 	struct power_supply		*power_supply;
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| 	struct regmap			*regmap;
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| 	struct delayed_work		work;
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| 	unsigned int			last_state;
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| };
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| 
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| static int sbs_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 sbs_info *chip = power_supply_get_drvdata(psy);
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| 	unsigned int reg;
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| 
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| 	reg = chip->last_state;
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| 
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| 	switch (psp) {
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| 	case POWER_SUPPLY_PROP_PRESENT:
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| 		val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT);
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| 		break;
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| 
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| 	case POWER_SUPPLY_PROP_ONLINE:
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| 		val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT);
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| 		break;
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| 
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| 	case POWER_SUPPLY_PROP_STATUS:
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| 		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
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| 
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| 		if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT))
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| 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
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| 		else if (reg & SBS_CHARGER_STATUS_AC_PRESENT &&
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| 			 !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED))
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| 			val->intval = POWER_SUPPLY_STATUS_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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| 
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| 	case POWER_SUPPLY_PROP_HEALTH:
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| 		if (reg & SBS_CHARGER_STATUS_RES_COLD)
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| 			val->intval = POWER_SUPPLY_HEALTH_COLD;
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| 		if (reg & SBS_CHARGER_STATUS_RES_HOT)
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| 			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
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| 		else
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| 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
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| 
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| 		break;
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| 
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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 int sbs_check_state(struct sbs_info *chip)
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| {
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| 	unsigned int reg;
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| 	int ret;
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| 
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| 	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®);
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| 	if (!ret && reg != chip->last_state) {
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| 		chip->last_state = reg;
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| 		power_supply_changed(chip->power_supply);
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| 		return 1;
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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 void sbs_delayed_work(struct work_struct *work)
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| {
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| 	struct sbs_info *chip = container_of(work, struct sbs_info, work.work);
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| 
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| 	sbs_check_state(chip);
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| 
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| 	schedule_delayed_work(&chip->work,
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| 			      msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
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| }
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| 
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| static irqreturn_t sbs_irq_thread(int irq, void *data)
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| {
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| 	struct sbs_info *chip = data;
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| 	int ret;
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| 
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| 	ret = sbs_check_state(chip);
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| 
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| 	return ret ? IRQ_HANDLED : IRQ_NONE;
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| }
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| 
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| static enum power_supply_property sbs_properties[] = {
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| 	POWER_SUPPLY_PROP_STATUS,
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| 	POWER_SUPPLY_PROP_PRESENT,
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| 	POWER_SUPPLY_PROP_ONLINE,
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| 	POWER_SUPPLY_PROP_HEALTH,
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| };
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| 
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| static bool sbs_readable_reg(struct device *dev, unsigned int reg)
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| {
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| 	return reg >= SBS_CHARGER_REG_SPEC_INFO;
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| }
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| 
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| static bool sbs_volatile_reg(struct device *dev, unsigned int reg)
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| {
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| 	switch (reg) {
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| 	case SBS_CHARGER_REG_STATUS:
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| 		return true;
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| 	}
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| 
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| 	return false;
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| }
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| 
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| static const struct regmap_config sbs_regmap = {
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| 	.reg_bits	= 8,
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| 	.val_bits	= 16,
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| 	.max_register	= SBS_CHARGER_REG_ALARM_WARNING,
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| 	.readable_reg	= sbs_readable_reg,
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| 	.volatile_reg	= sbs_volatile_reg,
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| 	.val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */
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| };
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| 
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| static const struct power_supply_desc sbs_desc = {
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| 	.name = "sbs-charger",
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| 	.type = POWER_SUPPLY_TYPE_MAINS,
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| 	.properties = sbs_properties,
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| 	.num_properties = ARRAY_SIZE(sbs_properties),
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| 	.get_property = sbs_get_property,
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| };
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| 
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| static int sbs_probe(struct i2c_client *client,
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| 		     const struct i2c_device_id *id)
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| {
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| 	struct power_supply_config psy_cfg = {};
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| 	struct sbs_info *chip;
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| 	int ret, val;
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| 
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| 	chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
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| 	if (!chip)
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| 		return -ENOMEM;
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| 
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| 	chip->client = client;
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| 	psy_cfg.of_node = client->dev.of_node;
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| 	psy_cfg.drv_data = chip;
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| 
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| 	i2c_set_clientdata(client, chip);
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| 
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| 	chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap);
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| 	if (IS_ERR(chip->regmap))
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| 		return PTR_ERR(chip->regmap);
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| 
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| 	/*
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| 	 * Before we register, we need to make sure we can actually talk
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| 	 * to the battery.
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| 	 */
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| 	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val);
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| 	if (ret)
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| 		return dev_err_probe(&client->dev, ret, "Failed to get device status\n");
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| 	chip->last_state = val;
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| 
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| 	chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, &psy_cfg);
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| 	if (IS_ERR(chip->power_supply))
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| 		return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply),
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| 				     "Failed to register power supply\n");
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| 
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| 	/*
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| 	 * The sbs-charger spec doesn't impose the use of an interrupt. So in
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| 	 * the case it wasn't provided we use polling in order get the charger's
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| 	 * status.
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| 	 */
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| 	if (client->irq) {
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| 		ret = devm_request_threaded_irq(&client->dev, client->irq,
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| 					NULL, sbs_irq_thread,
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| 					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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| 					dev_name(&client->dev), chip);
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| 		if (ret)
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| 			return dev_err_probe(&client->dev, ret, "Failed to request irq\n");
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| 	} else {
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| 		ret = devm_delayed_work_autocancel(&client->dev, &chip->work,
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| 						   sbs_delayed_work);
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| 		if (ret)
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| 			return dev_err_probe(&client->dev, ret,
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| 					     "Failed to init work for polling\n");
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| 
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| 		schedule_delayed_work(&chip->work,
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| 				      msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
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| 	}
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| 
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| 	dev_info(&client->dev,
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| 		 "%s: smart charger device registered\n", client->name);
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| 
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| 	return 0;
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| }
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| 
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| #ifdef CONFIG_OF
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| static const struct of_device_id sbs_dt_ids[] = {
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| 	{ .compatible = "sbs,sbs-charger" },
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| 	{ },
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| };
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| MODULE_DEVICE_TABLE(of, sbs_dt_ids);
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| #endif
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| 
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| static const struct i2c_device_id sbs_id[] = {
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| 	{ "sbs-charger", 0 },
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| 	{ }
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| };
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| MODULE_DEVICE_TABLE(i2c, sbs_id);
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| 
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| static struct i2c_driver sbs_driver = {
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| 	.probe		= sbs_probe,
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| 	.id_table	= sbs_id,
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| 	.driver = {
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| 		.name	= "sbs-charger",
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| 		.of_match_table = of_match_ptr(sbs_dt_ids),
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| 	},
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| };
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| module_i2c_driver(sbs_driver);
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| 
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| MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
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| MODULE_DESCRIPTION("SBS smart charger driver");
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| MODULE_LICENSE("GPL v2");
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