power: axp288_charger: axp288 charger driver

This patch adds new power supply charger driver support
for X-Power AXP288 PMIC integrated charger.

This driver interfaces with the axp20x mfd driver as a cell
and listens to extcon cable events for setting up charging.

Signed-off-by: Ramakrishna Pallala <[e-mail]>
Acked-by: Lee Jones <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/Kconfig

···
 	  This driver can also be built as a module. If so, the module will be
 	  called da9150-charger.
 
+config AXP288_CHARGER
+	tristate "X-Powers AXP288 Charger"
+	depends on MFD_AXP20X && EXTCON_AXP288
+	help
+	  Say yes here to have support X-Power AXP288 power management IC (PMIC)
+	  integrated charger.
+
 config AXP288_FUEL_GAUGE
 	tristate "X-Powers AXP288 Fuel Gauge"
 	depends on MFD_AXP20X && IIO

drivers/power/Makefile

···
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_POWER_RESET)	+= reset/
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
+obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o

drivers/power/axp288_charger.c

···
+/*
+ * axp288_charger.c - X-power AXP288 PMIC Charger driver
+ *
+ * Copyright (C) 2014 Intel Corporation
+ * Author: Ramakrishna Pallala <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/usb/otg.h>
+#include <linux/notifier.h>
+#include <linux/power_supply.h>
+#include <linux/notifier.h>
+#include <linux/property.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/extcon.h>
+
+#define PS_STAT_VBUS_TRIGGER		(1 << 0)
+#define PS_STAT_BAT_CHRG_DIR		(1 << 2)
+#define PS_STAT_VBAT_ABOVE_VHOLD	(1 << 3)
+#define PS_STAT_VBUS_VALID		(1 << 4)
+#define PS_STAT_VBUS_PRESENT		(1 << 5)
+
+#define CHRG_STAT_BAT_SAFE_MODE		(1 << 3)
+#define CHRG_STAT_BAT_VALID		(1 << 4)
+#define CHRG_STAT_BAT_PRESENT		(1 << 5)
+#define CHRG_STAT_CHARGING		(1 << 6)
+#define CHRG_STAT_PMIC_OTP		(1 << 7)
+
+#define VBUS_ISPOUT_CUR_LIM_MASK	0x03
+#define VBUS_ISPOUT_CUR_LIM_BIT_POS	0
+#define VBUS_ISPOUT_CUR_LIM_900MA	0x0	/* 900mA */
+#define VBUS_ISPOUT_CUR_LIM_1500MA	0x1	/* 1500mA */
+#define VBUS_ISPOUT_CUR_LIM_2000MA	0x2	/* 2000mA */
+#define VBUS_ISPOUT_CUR_NO_LIM		0x3	/* 2500mA */
+#define VBUS_ISPOUT_VHOLD_SET_MASK	0x31
+#define VBUS_ISPOUT_VHOLD_SET_BIT_POS	0x3
+#define VBUS_ISPOUT_VHOLD_SET_OFFSET	4000	/* 4000mV */
+#define VBUS_ISPOUT_VHOLD_SET_LSB_RES	100	/* 100mV */
+#define VBUS_ISPOUT_VHOLD_SET_4300MV	0x3	/* 4300mV */
+#define VBUS_ISPOUT_VBUS_PATH_DIS	(1 << 7)
+
+#define CHRG_CCCV_CC_MASK		0xf		/* 4 bits */
+#define CHRG_CCCV_CC_BIT_POS		0
+#define CHRG_CCCV_CC_OFFSET		200		/* 200mA */
+#define CHRG_CCCV_CC_LSB_RES		200		/* 200mA */
+#define CHRG_CCCV_ITERM_20P		(1 << 4)	/* 20% of CC */
+#define CHRG_CCCV_CV_MASK		0x60		/* 2 bits */
+#define CHRG_CCCV_CV_BIT_POS		5
+#define CHRG_CCCV_CV_4100MV		0x0		/* 4.10V */
+#define CHRG_CCCV_CV_4150MV		0x1		/* 4.15V */
+#define CHRG_CCCV_CV_4200MV		0x2		/* 4.20V */
+#define CHRG_CCCV_CV_4350MV		0x3		/* 4.35V */
+#define CHRG_CCCV_CHG_EN		(1 << 7)
+
+#define CNTL2_CC_TIMEOUT_MASK		0x3	/* 2 bits */
+#define CNTL2_CC_TIMEOUT_OFFSET		6	/* 6 Hrs */
+#define CNTL2_CC_TIMEOUT_LSB_RES	2	/* 2 Hrs */
+#define CNTL2_CC_TIMEOUT_12HRS		0x3	/* 12 Hrs */
+#define CNTL2_CHGLED_TYPEB		(1 << 4)
+#define CNTL2_CHG_OUT_TURNON		(1 << 5)
+#define CNTL2_PC_TIMEOUT_MASK		0xC0
+#define CNTL2_PC_TIMEOUT_OFFSET		40	/* 40 mins */
+#define CNTL2_PC_TIMEOUT_LSB_RES	10	/* 10 mins */
+#define CNTL2_PC_TIMEOUT_70MINS		0x3
+
+#define CHRG_ILIM_TEMP_LOOP_EN		(1 << 3)
+#define CHRG_VBUS_ILIM_MASK		0xf0
+#define CHRG_VBUS_ILIM_BIT_POS		4
+#define CHRG_VBUS_ILIM_100MA		0x0	/* 100mA */
+#define CHRG_VBUS_ILIM_500MA		0x1	/* 500mA */
+#define CHRG_VBUS_ILIM_900MA		0x2	/* 900mA */
+#define CHRG_VBUS_ILIM_1500MA		0x3	/* 1500mA */
+#define CHRG_VBUS_ILIM_2000MA		0x4	/* 2000mA */
+#define CHRG_VBUS_ILIM_2500MA		0x5	/* 2500mA */
+#define CHRG_VBUS_ILIM_3000MA		0x6	/* 3000mA */
+
+#define CHRG_VLTFC_0C			0xA5	/* 0 DegC */
+#define CHRG_VHTFC_45C			0x1F	/* 45 DegC */
+
+#define BAT_IRQ_CFG_CHRG_DONE		(1 << 2)
+#define BAT_IRQ_CFG_CHRG_START		(1 << 3)
+#define BAT_IRQ_CFG_BAT_SAFE_EXIT	(1 << 4)
+#define BAT_IRQ_CFG_BAT_SAFE_ENTER	(1 << 5)
+#define BAT_IRQ_CFG_BAT_DISCON		(1 << 6)
+#define BAT_IRQ_CFG_BAT_CONN		(1 << 7)
+#define BAT_IRQ_CFG_BAT_MASK		0xFC
+
+#define TEMP_IRQ_CFG_QCBTU		(1 << 4)
+#define TEMP_IRQ_CFG_CBTU		(1 << 5)
+#define TEMP_IRQ_CFG_QCBTO		(1 << 6)
+#define TEMP_IRQ_CFG_CBTO		(1 << 7)
+#define TEMP_IRQ_CFG_MASK		0xF0
+
+#define FG_CNTL_OCV_ADJ_EN		(1 << 3)
+
+#define CV_4100MV			4100	/* 4100mV */
+#define CV_4150MV			4150	/* 4150mV */
+#define CV_4200MV			4200	/* 4200mV */
+#define CV_4350MV			4350	/* 4350mV */
+
+#define CC_200MA			200	/*  200mA */
+#define CC_600MA			600	/*  600mA */
+#define CC_800MA			800	/*  800mA */
+#define CC_1000MA			1000	/* 1000mA */
+#define CC_1600MA			1600	/* 1600mA */
+#define CC_2000MA			2000	/* 2000mA */
+
+#define ILIM_100MA			100	/* 100mA */
+#define ILIM_500MA			500	/* 500mA */
+#define ILIM_900MA			900	/* 900mA */
+#define ILIM_1500MA			1500	/* 1500mA */
+#define ILIM_2000MA			2000	/* 2000mA */
+#define ILIM_2500MA			2500	/* 2500mA */
+#define ILIM_3000MA			3000	/* 3000mA */
+
+#define AXP288_EXTCON_DEV_NAME		"axp288_extcon"
+
+#define AXP288_EXTCON_SLOW_CHARGER		"SLOW-CHARGER"
+#define AXP288_EXTCON_DOWNSTREAM_CHARGER	"CHARGE-DOWNSTREAM"
+#define AXP288_EXTCON_FAST_CHARGER		"FAST-CHARGER"
+
+enum {
+	VBUS_OV_IRQ = 0,
+	CHARGE_DONE_IRQ,
+	CHARGE_CHARGING_IRQ,
+	BAT_SAFE_QUIT_IRQ,
+	BAT_SAFE_ENTER_IRQ,
+	QCBTU_IRQ,
+	CBTU_IRQ,
+	QCBTO_IRQ,
+	CBTO_IRQ,
+	CHRG_INTR_END,
+};
+
+struct axp288_chrg_info {
+	struct platform_device *pdev;
+	struct axp20x_chrg_pdata *pdata;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *regmap_irqc;
+	int irq[CHRG_INTR_END];
+	struct power_supply *psy_usb;
+	struct mutex lock;
+
+	/* OTG/Host mode */
+	struct {
+		struct work_struct work;
+		struct extcon_specific_cable_nb cable;
+		struct notifier_block id_nb;
+		bool id_short;
+	} otg;
+
+	/* SDP/CDP/DCP USB charging cable notifications */
+	struct {
+		struct extcon_dev *edev;
+		bool connected;
+		enum power_supply_type chg_type;
+		struct notifier_block nb;
+		struct work_struct work;
+	} cable;
+
+	int health;
+	int inlmt;
+	int cc;
+	int cv;
+	int max_cc;
+	int max_cv;
+	bool online;
+	bool present;
+	bool enable_charger;
+	bool is_charger_enabled;
+};
+
+static inline int axp288_charger_set_cc(struct axp288_chrg_info *info, int cc)
+{
+	u8 reg_val;
+	int ret;
+
+	if (cc < CHRG_CCCV_CC_OFFSET)
+		cc = CHRG_CCCV_CC_OFFSET;
+	else if (cc > info->max_cc)
+		cc = info->max_cc;
+
+	reg_val = (cc - CHRG_CCCV_CC_OFFSET) / CHRG_CCCV_CC_LSB_RES;
+	cc = (reg_val * CHRG_CCCV_CC_LSB_RES) + CHRG_CCCV_CC_OFFSET;
+	reg_val = reg_val << CHRG_CCCV_CC_BIT_POS;
+
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_CHRG_CTRL1,
+				CHRG_CCCV_CC_MASK, reg_val);
+	if (ret >= 0)
+		info->cc = cc;
+
+	return ret;
+}
+
+static inline int axp288_charger_set_cv(struct axp288_chrg_info *info, int cv)
+{
+	u8 reg_val;
+	int ret;
+
+	if (cv <= CV_4100MV) {
+		reg_val = CHRG_CCCV_CV_4100MV;
+		cv = CV_4100MV;
+	} else if (cv <= CV_4150MV) {
+		reg_val = CHRG_CCCV_CV_4150MV;
+		cv = CV_4150MV;
+	} else if (cv <= CV_4200MV) {
+		reg_val = CHRG_CCCV_CV_4200MV;
+		cv = CV_4200MV;
+	} else {
+		reg_val = CHRG_CCCV_CV_4350MV;
+		cv = CV_4350MV;
+	}
+
+	reg_val = reg_val << CHRG_CCCV_CV_BIT_POS;
+
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_CHRG_CTRL1,
+				CHRG_CCCV_CV_MASK, reg_val);
+
+	if (ret >= 0)
+		info->cv = cv;
+
+	return ret;
+}
+
+static inline int axp288_charger_set_vbus_inlmt(struct axp288_chrg_info *info,
+					   int inlmt)
+{
+	int ret;
+	unsigned int val;
+	u8 reg_val;
+
+	/* Read in limit register */
+	ret = regmap_read(info->regmap, AXP20X_CHRG_BAK_CTRL, &val);
+	if (ret < 0)
+		goto set_inlmt_fail;
+
+	if (inlmt <= ILIM_100MA) {
+		reg_val = CHRG_VBUS_ILIM_100MA;
+		inlmt = ILIM_100MA;
+	} else if (inlmt <= ILIM_500MA) {
+		reg_val = CHRG_VBUS_ILIM_500MA;
+		inlmt = ILIM_500MA;
+	} else if (inlmt <= ILIM_900MA) {
+		reg_val = CHRG_VBUS_ILIM_900MA;
+		inlmt = ILIM_900MA;
+	} else if (inlmt <= ILIM_1500MA) {
+		reg_val = CHRG_VBUS_ILIM_1500MA;
+		inlmt = ILIM_1500MA;
+	} else if (inlmt <= ILIM_2000MA) {
+		reg_val = CHRG_VBUS_ILIM_2000MA;
+		inlmt = ILIM_2000MA;
+	} else if (inlmt <= ILIM_2500MA) {
+		reg_val = CHRG_VBUS_ILIM_2500MA;
+		inlmt = ILIM_2500MA;
+	} else {
+		reg_val = CHRG_VBUS_ILIM_3000MA;
+		inlmt = ILIM_3000MA;
+	}
+
+	reg_val = (val & ~CHRG_VBUS_ILIM_MASK)
+			| (reg_val << CHRG_VBUS_ILIM_BIT_POS);
+	ret = regmap_write(info->regmap, AXP20X_CHRG_BAK_CTRL, reg_val);
+	if (ret >= 0)
+		info->inlmt = inlmt;
+	else
+		dev_err(&info->pdev->dev, "charger BAK control %d\n", ret);
+
+
+set_inlmt_fail:
+	return ret;
+}
+
+static int axp288_charger_vbus_path_select(struct axp288_chrg_info *info,
+								bool enable)
+{
+	int ret;
+
+	if (enable)
+		ret = regmap_update_bits(info->regmap, AXP20X_VBUS_IPSOUT_MGMT,
+					VBUS_ISPOUT_VBUS_PATH_DIS, 0);
+	else
+		ret = regmap_update_bits(info->regmap, AXP20X_VBUS_IPSOUT_MGMT,
+			VBUS_ISPOUT_VBUS_PATH_DIS, VBUS_ISPOUT_VBUS_PATH_DIS);
+
+	if (ret < 0)
+		dev_err(&info->pdev->dev, "axp288 vbus path select %d\n", ret);
+
+
+	return ret;
+}
+
+static int axp288_charger_enable_charger(struct axp288_chrg_info *info,
+								bool enable)
+{
+	int ret;
+
+	if (enable)
+		ret = regmap_update_bits(info->regmap, AXP20X_CHRG_CTRL1,
+				CHRG_CCCV_CHG_EN, CHRG_CCCV_CHG_EN);
+	else
+		ret = regmap_update_bits(info->regmap, AXP20X_CHRG_CTRL1,
+				CHRG_CCCV_CHG_EN, 0);
+	if (ret < 0)
+		dev_err(&info->pdev->dev, "axp288 enable charger %d\n", ret);
+	else
+		info->is_charger_enabled = enable;
+
+	return ret;
+}
+
+static int axp288_charger_is_present(struct axp288_chrg_info *info)
+{
+	int ret, present = 0;
+	unsigned int val;
+
+	ret = regmap_read(info->regmap, AXP20X_PWR_INPUT_STATUS, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val & PS_STAT_VBUS_PRESENT)
+		present = 1;
+	return present;
+}
+
+static int axp288_charger_is_online(struct axp288_chrg_info *info)
+{
+	int ret, online = 0;
+	unsigned int val;
+
+	ret = regmap_read(info->regmap, AXP20X_PWR_INPUT_STATUS, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val & PS_STAT_VBUS_VALID)
+		online = 1;
+	return online;
+}
+
+static int axp288_get_charger_health(struct axp288_chrg_info *info)
+{
+	int ret, pwr_stat, chrg_stat;
+	int health = POWER_SUPPLY_HEALTH_UNKNOWN;
+	unsigned int val;
+
+	ret = regmap_read(info->regmap, AXP20X_PWR_INPUT_STATUS, &val);
+	if ((ret < 0) || !(val & PS_STAT_VBUS_PRESENT))
+		goto health_read_fail;
+	else
+		pwr_stat = val;
+
+	ret = regmap_read(info->regmap, AXP20X_PWR_OP_MODE, &val);
+	if (ret < 0)
+		goto health_read_fail;
+	else
+		chrg_stat = val;
+
+	if (!(pwr_stat & PS_STAT_VBUS_VALID))
+		health = POWER_SUPPLY_HEALTH_DEAD;
+	else if (chrg_stat & CHRG_STAT_PMIC_OTP)
+		health = POWER_SUPPLY_HEALTH_OVERHEAT;
+	else if (chrg_stat & CHRG_STAT_BAT_SAFE_MODE)
+		health = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+	else
+		health = POWER_SUPPLY_HEALTH_GOOD;
+
+health_read_fail:
+	return health;
+}
+
+static int axp288_charger_usb_set_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    const union power_supply_propval *val)
+{
+	struct axp288_chrg_info *info = power_supply_get_drvdata(psy);
+	int ret = 0;
+	int scaled_val;
+
+	mutex_lock(&info->lock);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		scaled_val = min(val->intval, info->max_cc);
+		scaled_val = DIV_ROUND_CLOSEST(scaled_val, 1000);
+		ret = axp288_charger_set_cc(info, scaled_val);
+		if (ret < 0)
+			dev_warn(&info->pdev->dev, "set charge current failed\n");
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		scaled_val = min(val->intval, info->max_cv);
+		scaled_val = DIV_ROUND_CLOSEST(scaled_val, 1000);
+		ret = axp288_charger_set_cv(info, scaled_val);
+		if (ret < 0)
+			dev_warn(&info->pdev->dev, "set charge voltage failed\n");
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	mutex_unlock(&info->lock);
+	return ret;
+}
+
+static int axp288_charger_usb_get_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct axp288_chrg_info *info = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	mutex_lock(&info->lock);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		/* Check for OTG case first */
+		if (info->otg.id_short) {
+			val->intval = 0;
+			break;
+		}
+		ret = axp288_charger_is_present(info);
+		if (ret < 0)
+			goto psy_get_prop_fail;
+		info->present = ret;
+		val->intval = info->present;
+		break;
+	case POWER_SUPPLY_PROP_ONLINE:
+		/* Check for OTG case first */
+		if (info->otg.id_short) {
+			val->intval = 0;
+			break;
+		}
+		ret = axp288_charger_is_online(info);
+		if (ret < 0)
+			goto psy_get_prop_fail;
+		info->online = ret;
+		val->intval = info->online;
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		val->intval = axp288_get_charger_health(info);
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		val->intval = info->cc * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		val->intval = info->max_cc * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		val->intval = info->cv * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		val->intval = info->max_cv * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT:
+		val->intval = info->inlmt * 1000;
+		break;
+	default:
+		ret = -EINVAL;
+		goto psy_get_prop_fail;
+	}
+
+psy_get_prop_fail:
+	mutex_unlock(&info->lock);
+	return ret;
+}
+
+static int axp288_charger_property_is_writeable(struct power_supply *psy,
+		enum power_supply_property psp)
+{
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		ret = 1;
+		break;
+	default:
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property axp288_usb_props[] = {
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_TYPE,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
+};
+
+static const struct power_supply_desc axp288_charger_desc = {
+	.name			= "axp288_charger",
+	.type			= POWER_SUPPLY_TYPE_USB,
+	.properties		= axp288_usb_props,
+	.num_properties		= ARRAY_SIZE(axp288_usb_props),
+	.get_property		= axp288_charger_usb_get_property,
+	.set_property		= axp288_charger_usb_set_property,
+	.property_is_writeable	= axp288_charger_property_is_writeable,
+};
+
+static irqreturn_t axp288_charger_irq_thread_handler(int irq, void *dev)
+{
+	struct axp288_chrg_info *info = dev;
+	int i;
+
+	for (i = 0; i < CHRG_INTR_END; i++) {
+		if (info->irq[i] == irq)
+			break;
+	}
+
+	if (i >= CHRG_INTR_END) {
+		dev_warn(&info->pdev->dev, "spurious interrupt!!\n");
+		return IRQ_NONE;
+	}
+
+	switch (i) {
+	case VBUS_OV_IRQ:
+		dev_dbg(&info->pdev->dev, "VBUS Over Voltage INTR\n");
+		break;
+	case CHARGE_DONE_IRQ:
+		dev_dbg(&info->pdev->dev, "Charging Done INTR\n");
+		break;
+	case CHARGE_CHARGING_IRQ:
+		dev_dbg(&info->pdev->dev, "Start Charging IRQ\n");
+		break;
+	case BAT_SAFE_QUIT_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Quit Safe Mode(restart timer) Charging IRQ\n");
+		break;
+	case BAT_SAFE_ENTER_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Enter Safe Mode(timer expire) Charging IRQ\n");
+		break;
+	case QCBTU_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Quit Battery Under Temperature(CHRG) INTR\n");
+		break;
+	case CBTU_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Hit Battery Under Temperature(CHRG) INTR\n");
+		break;
+	case QCBTO_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Quit Battery Over Temperature(CHRG) INTR\n");
+		break;
+	case CBTO_IRQ:
+		dev_dbg(&info->pdev->dev,
+			"Hit Battery Over Temperature(CHRG) INTR\n");
+		break;
+	default:
+		dev_warn(&info->pdev->dev, "Spurious Interrupt!!!\n");
+		goto out;
+	}
+
+	power_supply_changed(info->psy_usb);
+out:
+	return IRQ_HANDLED;
+}
+
+static void axp288_charger_extcon_evt_worker(struct work_struct *work)
+{
+	struct axp288_chrg_info *info =
+	    container_of(work, struct axp288_chrg_info, cable.work);
+	int ret, current_limit;
+	bool changed = false;
+	struct extcon_dev *edev = info->cable.edev;
+	bool old_connected = info->cable.connected;
+
+	/* Determine cable/charger type */
+	if (extcon_get_cable_state(edev, AXP288_EXTCON_SLOW_CHARGER) > 0) {
+		dev_dbg(&info->pdev->dev, "USB SDP charger  is connected");
+		info->cable.connected = true;
+		info->cable.chg_type = POWER_SUPPLY_TYPE_USB;
+	} else if (extcon_get_cable_state(edev,
+				AXP288_EXTCON_DOWNSTREAM_CHARGER) > 0) {
+		dev_dbg(&info->pdev->dev, "USB CDP charger is connected");
+		info->cable.connected = true;
+		info->cable.chg_type = POWER_SUPPLY_TYPE_USB_CDP;
+	} else if (extcon_get_cable_state(edev,
+					AXP288_EXTCON_FAST_CHARGER) > 0) {
+		dev_dbg(&info->pdev->dev, "USB DCP charger is connected");
+		info->cable.connected = true;
+		info->cable.chg_type = POWER_SUPPLY_TYPE_USB_DCP;
+	} else {
+		if (old_connected)
+			dev_dbg(&info->pdev->dev, "USB charger disconnected");
+		info->cable.connected = false;
+		info->cable.chg_type = POWER_SUPPLY_TYPE_USB;
+	}
+
+	/* Cable status changed */
+	if (old_connected != info->cable.connected)
+		changed = true;
+
+	if (!changed)
+		return;
+
+	mutex_lock(&info->lock);
+
+	if (info->is_charger_enabled && !info->cable.connected) {
+		info->enable_charger = false;
+		ret = axp288_charger_enable_charger(info, info->enable_charger);
+		if (ret < 0)
+			dev_err(&info->pdev->dev,
+				"cannot disable charger (%d)", ret);
+
+	} else if (!info->is_charger_enabled && info->cable.connected) {
+		switch (info->cable.chg_type) {
+		case POWER_SUPPLY_TYPE_USB:
+			current_limit = ILIM_500MA;
+			break;
+		case POWER_SUPPLY_TYPE_USB_CDP:
+			current_limit = ILIM_1500MA;
+			break;
+		case POWER_SUPPLY_TYPE_USB_DCP:
+			current_limit = ILIM_2000MA;
+			break;
+		default:
+			/* Unknown */
+			current_limit = 0;
+			break;
+		}
+
+		/* Set vbus current limit first, then enable charger */
+		ret = axp288_charger_set_vbus_inlmt(info, current_limit);
+		if (ret < 0) {
+			dev_err(&info->pdev->dev,
+				"error setting current limit (%d)", ret);
+		} else {
+			info->enable_charger = (current_limit > 0);
+			ret = axp288_charger_enable_charger(info,
+							info->enable_charger);
+			if (ret < 0)
+				dev_err(&info->pdev->dev,
+					"cannot enable charger (%d)", ret);
+		}
+	}
+
+	if (changed)
+		info->health = axp288_get_charger_health(info);
+
+	mutex_unlock(&info->lock);
+
+	if (changed)
+		power_supply_changed(info->psy_usb);
+}
+
+static int axp288_charger_handle_cable_evt(struct notifier_block *nb,
+					  unsigned long event, void *param)
+{
+	struct axp288_chrg_info *info =
+	    container_of(nb, struct axp288_chrg_info, cable.nb);
+
+	schedule_work(&info->cable.work);
+
+	return NOTIFY_OK;
+}
+
+static void axp288_charger_otg_evt_worker(struct work_struct *work)
+{
+	struct axp288_chrg_info *info =
+	    container_of(work, struct axp288_chrg_info, otg.work);
+	int ret;
+
+	/* Disable VBUS path before enabling the 5V boost */
+	ret = axp288_charger_vbus_path_select(info, !info->otg.id_short);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "vbus path disable failed\n");
+}
+
+static int axp288_charger_handle_otg_evt(struct notifier_block *nb,
+				   unsigned long event, void *param)
+{
+	struct axp288_chrg_info *info =
+	    container_of(nb, struct axp288_chrg_info, otg.id_nb);
+	struct extcon_dev *edev = param;
+	int usb_host = extcon_get_cable_state(edev, "USB-Host");
+
+	dev_dbg(&info->pdev->dev, "external connector USB-Host is %s\n",
+				usb_host ? "attached" : "detached");
+
+	/*
+	 * Set usb_id_short flag to avoid running charger detection logic
+	 * in case usb host.
+	 */
+	info->otg.id_short = usb_host;
+	schedule_work(&info->otg.work);
+
+	return NOTIFY_OK;
+}
+
+static void charger_init_hw_regs(struct axp288_chrg_info *info)
+{
+	int ret, cc, cv;
+	unsigned int val;
+
+	/* Program temperature thresholds */
+	ret = regmap_write(info->regmap, AXP20X_V_LTF_CHRG, CHRG_VLTFC_0C);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+							AXP20X_V_LTF_CHRG, ret);
+
+	ret = regmap_write(info->regmap, AXP20X_V_HTF_CHRG, CHRG_VHTFC_45C);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+							AXP20X_V_HTF_CHRG, ret);
+
+	/* Do not turn-off charger o/p after charge cycle ends */
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_CHRG_CTRL2,
+				CNTL2_CHG_OUT_TURNON, 1);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+						AXP20X_CHRG_CTRL2, ret);
+
+	/* Enable interrupts */
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_IRQ2_EN,
+				BAT_IRQ_CFG_BAT_MASK, 1);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+						AXP20X_IRQ2_EN, ret);
+
+	ret = regmap_update_bits(info->regmap, AXP20X_IRQ3_EN,
+				TEMP_IRQ_CFG_MASK, 1);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+						AXP20X_IRQ3_EN, ret);
+
+	/* Setup ending condition for charging to be 10% of I(chrg) */
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_CHRG_CTRL1,
+				CHRG_CCCV_ITERM_20P, 0);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+						AXP20X_CHRG_CTRL1, ret);
+
+	/* Disable OCV-SOC curve calibration */
+	ret = regmap_update_bits(info->regmap,
+				AXP20X_CC_CTRL,
+				FG_CNTL_OCV_ADJ_EN, 0);
+	if (ret < 0)
+		dev_warn(&info->pdev->dev, "register(%x) write error(%d)\n",
+						AXP20X_CC_CTRL, ret);
+
+	/* Init charging current and voltage */
+	info->max_cc = info->pdata->max_cc;
+	info->max_cv = info->pdata->max_cv;
+
+	/* Read current charge voltage and current limit */
+	ret = regmap_read(info->regmap, AXP20X_CHRG_CTRL1, &val);
+	if (ret < 0) {
+		/* Assume default if cannot read */
+		info->cc = info->pdata->def_cc;
+		info->cv = info->pdata->def_cv;
+	} else {
+		/* Determine charge voltage */
+		cv = (val & CHRG_CCCV_CV_MASK) >> CHRG_CCCV_CV_BIT_POS;
+		switch (cv) {
+		case CHRG_CCCV_CV_4100MV:
+			info->cv = CV_4100MV;
+			break;
+		case CHRG_CCCV_CV_4150MV:
+			info->cv = CV_4150MV;
+			break;
+		case CHRG_CCCV_CV_4200MV:
+			info->cv = CV_4200MV;
+			break;
+		case CHRG_CCCV_CV_4350MV:
+			info->cv = CV_4350MV;
+			break;
+		default:
+			info->cv = INT_MAX;
+			break;
+		}
+
+		/* Determine charge current limit */
+		cc = (ret & CHRG_CCCV_CC_MASK) >> CHRG_CCCV_CC_BIT_POS;
+		cc = (cc * CHRG_CCCV_CC_LSB_RES) + CHRG_CCCV_CC_OFFSET;
+		info->cc = cc;
+
+		/* Program default charging voltage and current */
+		cc = min(info->pdata->def_cc, info->max_cc);
+		cv = min(info->pdata->def_cv, info->max_cv);
+
+		ret = axp288_charger_set_cc(info, cc);
+		if (ret < 0)
+			dev_warn(&info->pdev->dev,
+					"error(%d) in setting CC\n", ret);
+
+		ret = axp288_charger_set_cv(info, cv);
+		if (ret < 0)
+			dev_warn(&info->pdev->dev,
+					"error(%d) in setting CV\n", ret);
+	}
+}
+
+static int axp288_charger_probe(struct platform_device *pdev)
+{
+	int ret, i, pirq;
+	struct axp288_chrg_info *info;
+	struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+	struct power_supply_config charger_cfg = {};
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->pdev = pdev;
+	info->regmap = axp20x->regmap;
+	info->regmap_irqc = axp20x->regmap_irqc;
+	info->pdata = pdev->dev.platform_data;
+
+	if (!info->pdata) {
+		/* Try ACPI provided pdata via device properties */
+		if (!device_property_present(&pdev->dev,
+						"axp288_charger_data\n"))
+			dev_err(&pdev->dev, "failed to get platform data\n");
+		return -ENODEV;
+	}
+
+	info->cable.edev = extcon_get_extcon_dev(AXP288_EXTCON_DEV_NAME);
+	if (info->cable.edev == NULL) {
+		dev_dbg(&pdev->dev, "%s is not ready, probe deferred\n",
+			AXP288_EXTCON_DEV_NAME);
+		return -EPROBE_DEFER;
+	}
+
+	/* Register for extcon notification */
+	INIT_WORK(&info->cable.work, axp288_charger_extcon_evt_worker);
+	info->cable.nb.notifier_call = axp288_charger_handle_cable_evt;
+	ret = extcon_register_notifier(info->cable.edev, &info->cable.nb);
+	if (ret) {
+		dev_err(&info->pdev->dev,
+			"failed to register extcon notifier %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, info);
+	mutex_init(&info->lock);
+
+	/* Register with power supply class */
+	charger_cfg.drv_data = info;
+	info->psy_usb = power_supply_register(&pdev->dev, &axp288_charger_desc,
+						&charger_cfg);
+	if (IS_ERR(info->psy_usb)) {
+		dev_err(&pdev->dev, "failed to register power supply charger\n");
+		ret = PTR_ERR(info->psy_usb);
+		goto psy_reg_failed;
+	}
+
+	/* Register for OTG notification */
+	INIT_WORK(&info->otg.work, axp288_charger_otg_evt_worker);
+	info->otg.id_nb.notifier_call = axp288_charger_handle_otg_evt;
+	ret = extcon_register_interest(&info->otg.cable, NULL, "USB-Host",
+				       &info->otg.id_nb);
+	if (ret)
+		dev_warn(&pdev->dev, "failed to register otg notifier\n");
+
+	if (info->otg.cable.edev)
+		info->otg.id_short = extcon_get_cable_state(
+					info->otg.cable.edev, "USB-Host");
+
+	/* Register charger interrupts */
+	for (i = 0; i < CHRG_INTR_END; i++) {
+		pirq = platform_get_irq(info->pdev, i);
+		info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
+		if (info->irq[i] < 0) {
+			dev_warn(&info->pdev->dev,
+				"failed to get virtual interrupt=%d\n", pirq);
+			ret = info->irq[i];
+			goto intr_reg_failed;
+		}
+		ret = devm_request_threaded_irq(&info->pdev->dev, info->irq[i],
+					NULL, axp288_charger_irq_thread_handler,
+					IRQF_ONESHOT, info->pdev->name, info);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to request interrupt=%d\n",
+								info->irq[i]);
+			goto intr_reg_failed;
+		}
+	}
+
+	charger_init_hw_regs(info);
+
+	return 0;
+
+intr_reg_failed:
+	if (info->otg.cable.edev)
+		extcon_unregister_interest(&info->otg.cable);
+	power_supply_unregister(info->psy_usb);
+psy_reg_failed:
+	extcon_unregister_notifier(info->cable.edev, &info->cable.nb);
+	return ret;
+}
+
+static int axp288_charger_remove(struct platform_device *pdev)
+{
+	struct axp288_chrg_info *info =  dev_get_drvdata(&pdev->dev);
+
+	if (info->otg.cable.edev)
+		extcon_unregister_interest(&info->otg.cable);
+
+	extcon_unregister_notifier(info->cable.edev, &info->cable.nb);
+	power_supply_unregister(info->psy_usb);
+
+	return 0;
+}
+
+static struct platform_driver axp288_charger_driver = {
+	.probe = axp288_charger_probe,
+	.remove = axp288_charger_remove,
+	.driver = {
+		.name = "axp288_charger",
+	},
+};
+
+module_platform_driver(axp288_charger_driver);
+
+MODULE_AUTHOR("Ramakrishna Pallala <[e-mail]>");
+MODULE_DESCRIPTION("X-power AXP288 Charger Driver");
+MODULE_LICENSE("GPL v2");

include/linux/mfd/axp20x.h

···
 	int thermistor_curve[MAX_THERM_CURVE_SIZE][2];
 };
 
+struct axp20x_chrg_pdata {
+	int max_cc;
+	int max_cv;
+	int def_cc;
+	int def_cv;
+};
+
 #endif /* __LINUX_MFD_AXP20X_H */