power: max77693: Add charger driver for Maxim 77693

Add new driver for Maxim 77693 switch-mode charger (part of max77693
MFD driver) providing power supply class information to userspace.

The charger has +20V tolerant input. Current input can be set from 0 to
2.58 A. The charger can deliver up to 2.1 A to the battery or 3.5 A to
the system (when supplying additional current from battery to system).

The driver is configured through DTS (battery and system related
settings) and sysfs entries (timers and top-off charging threshold).

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

3 files changed, 765 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index da6981f92697..110d4bc03483 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -332,6 +332,12 @@ config CHARGER_MAX14577
           Say Y to enable support for the battery charger control sysfs and
           platform data of MAX14577/77836 MUICs.
 
+config CHARGER_MAX77693
+        tristate "Maxim MAX77693 battery charger driver"
+        depends on MFD_MAX77693
+        help
+          Say Y to enable support for the Maxim MAX77693 battery charger.
+
 config CHARGER_MAX8997
         tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
         depends on MFD_MAX8997 && REGULATOR_MAX8997
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b83a0c749781..31216cb7e8a1 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_CHARGER_LP8788)	+= lp8788-charger.o
 obj-$(CONFIG_CHARGER_GPIO)      += gpio-charger.o
 obj-$(CONFIG_CHARGER_MANAGER)   += charger-manager.o
 obj-$(CONFIG_CHARGER_MAX14577)  += max14577_charger.o
+obj-$(CONFIG_CHARGER_MAX77693)  += max77693_charger.o
 obj-$(CONFIG_CHARGER_MAX8997)   += max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)   += max8998_charger.o
 obj-$(CONFIG_CHARGER_BQ2415X)   += bq2415x_charger.o
diff --git a/drivers/power/max77693_charger.c b/drivers/power/max77693_charger.c
new file mode 100644
index 000000000000..56cf2177aad4
--- /dev/null
+++ b/drivers/power/max77693_charger.c
@@ -0,0 +1,758 @@
+/*
+ * max77693_charger.c - Battery charger driver for the Maxim 77693
+ *
+ * Copyright (C) 2014 Samsung Electronics
+ * Krzysztof Kozlowski <k.kozlowski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/mfd/max77693.h>
+#include <linux/mfd/max77693-private.h>
+
+static const char *max77693_charger_name                = "max77693-charger";
+static const char *max77693_charger_model               = "MAX77693";
+static const char *max77693_charger_manufacturer        = "Maxim Integrated";
+
+struct max77693_charger {
+        struct device           *dev;
+        struct max77693_dev     *max77693;
+        struct power_supply     charger;
+
+        u32 constant_volt;
+        u32 min_system_volt;
+        u32 thermal_regulation_temp;
+        u32 batttery_overcurrent;
+        u32 charge_input_threshold_volt;
+};
+
+static int max77693_get_charger_state(struct regmap *regmap)
+{
+        int state;
+        unsigned int data;
+
+        if (regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data) < 0)
+                return POWER_SUPPLY_STATUS_UNKNOWN;
+
+        data &= CHG_DETAILS_01_CHG_MASK;
+        data >>= CHG_DETAILS_01_CHG_SHIFT;
+
+        switch (data) {
+        case MAX77693_CHARGING_PREQUALIFICATION:
+        case MAX77693_CHARGING_FAST_CONST_CURRENT:
+        case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
+        case MAX77693_CHARGING_TOP_OFF:
+        /* In high temp the charging current is reduced, but still charging */
+        case MAX77693_CHARGING_HIGH_TEMP:
+                state = POWER_SUPPLY_STATUS_CHARGING;
+                break;
+        case MAX77693_CHARGING_DONE:
+                state = POWER_SUPPLY_STATUS_FULL;
+                break;
+        case MAX77693_CHARGING_TIMER_EXPIRED:
+        case MAX77693_CHARGING_THERMISTOR_SUSPEND:
+                state = POWER_SUPPLY_STATUS_NOT_CHARGING;
+                break;
+        case MAX77693_CHARGING_OFF:
+        case MAX77693_CHARGING_OVER_TEMP:
+        case MAX77693_CHARGING_WATCHDOG_EXPIRED:
+                state = POWER_SUPPLY_STATUS_DISCHARGING;
+                break;
+        case MAX77693_CHARGING_RESERVED:
+        default:
+                state = POWER_SUPPLY_STATUS_UNKNOWN;
+        }
+
+        return state;
+}
+
+static int max77693_get_charge_type(struct regmap *regmap)
+{
+        int state;
+        unsigned int data;
+
+        if (regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data) < 0)
+                return POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+
+        data &= CHG_DETAILS_01_CHG_MASK;
+        data >>= CHG_DETAILS_01_CHG_SHIFT;
+
+        switch (data) {
+        case MAX77693_CHARGING_PREQUALIFICATION:
+        /*
+         * Top-off: trickle or fast? In top-off the current varies between
+         * 100 and 250 mA. It is higher than prequalification current.
+         */
+        case MAX77693_CHARGING_TOP_OFF:
+                state = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+                break;
+        case MAX77693_CHARGING_FAST_CONST_CURRENT:
+        case MAX77693_CHARGING_FAST_CONST_VOLTAGE:
+        /* In high temp the charging current is reduced, but still charging */
+        case MAX77693_CHARGING_HIGH_TEMP:
+                state = POWER_SUPPLY_CHARGE_TYPE_FAST;
+                break;
+        case MAX77693_CHARGING_DONE:
+        case MAX77693_CHARGING_TIMER_EXPIRED:
+        case MAX77693_CHARGING_THERMISTOR_SUSPEND:
+        case MAX77693_CHARGING_OFF:
+        case MAX77693_CHARGING_OVER_TEMP:
+        case MAX77693_CHARGING_WATCHDOG_EXPIRED:
+                state = POWER_SUPPLY_CHARGE_TYPE_NONE;
+                break;
+        case MAX77693_CHARGING_RESERVED:
+        default:
+                state = POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+        }
+
+        return state;
+}
+
+/*
+ * Supported health statuses:
+ *  - POWER_SUPPLY_HEALTH_DEAD
+ *  - POWER_SUPPLY_HEALTH_GOOD
+ *  - POWER_SUPPLY_HEALTH_OVERVOLTAGE
+ *  - POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE
+ *  - POWER_SUPPLY_HEALTH_UNKNOWN
+ *  - POWER_SUPPLY_HEALTH_UNSPEC_FAILURE
+ */
+static int max77693_get_battery_health(struct regmap *regmap)
+{
+        int state;
+        unsigned int data;
+
+        if (regmap_read(regmap, MAX77693_CHG_REG_CHG_DETAILS_01, &data) < 0)
+                return POWER_SUPPLY_HEALTH_UNKNOWN;
+
+        data &= CHG_DETAILS_01_BAT_MASK;
+        data >>= CHG_DETAILS_01_BAT_SHIFT;
+
+        switch (data) {
+        case MAX77693_BATTERY_NOBAT:
+                state = POWER_SUPPLY_HEALTH_DEAD;
+                break;
+        case MAX77693_BATTERY_PREQUALIFICATION:
+        case MAX77693_BATTERY_GOOD:
+        case MAX77693_BATTERY_LOWVOLTAGE:
+                state = POWER_SUPPLY_HEALTH_GOOD;
+                break;
+        case MAX77693_BATTERY_TIMER_EXPIRED:
+                /*
+                 * Took longer to charge than expected, charging suspended.
+                 * Damaged battery?
+                 */
+                state = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+                break;
+        case MAX77693_BATTERY_OVERVOLTAGE:
+                state = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+                break;
+        case MAX77693_BATTERY_OVERCURRENT:
+                state = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+                break;
+        case MAX77693_BATTERY_RESERVED:
+        default:
+                state = POWER_SUPPLY_HEALTH_UNKNOWN;
+                break;
+        }
+
+        return state;
+}
+
+static int max77693_get_present(struct regmap *regmap)
+{
+        unsigned int data;
+
+        /*
+         * Read CHG_INT_OK register. High DETBAT bit here should be
+         * equal to value 0x0 in CHG_DETAILS_01/BAT field.
+         */
+        regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
+        if (data & CHG_INT_OK_DETBAT_MASK)
+                return 0;
+        return 1;
+}
+
+static int max77693_get_online(struct regmap *regmap)
+{
+        unsigned int data;
+
+        regmap_read(regmap, MAX77693_CHG_REG_CHG_INT_OK, &data);
+        if (data & CHG_INT_OK_CHGIN_MASK)
+                return 1;
+        return 0;
+}
+
+static enum power_supply_property max77693_charger_props[] = {
+        POWER_SUPPLY_PROP_STATUS,
+        POWER_SUPPLY_PROP_CHARGE_TYPE,
+        POWER_SUPPLY_PROP_HEALTH,
+        POWER_SUPPLY_PROP_PRESENT,
+        POWER_SUPPLY_PROP_ONLINE,
+        POWER_SUPPLY_PROP_MODEL_NAME,
+        POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static int max77693_charger_get_property(struct power_supply *psy,
+                            enum power_supply_property psp,
+                            union power_supply_propval *val)
+{
+        struct max77693_charger *chg = container_of(psy,
+                                                  struct max77693_charger,
+                                                  charger);
+        struct regmap *regmap = chg->max77693->regmap;
+        int ret = 0;
+
+        switch (psp) {
+        case POWER_SUPPLY_PROP_STATUS:
+                val->intval = max77693_get_charger_state(regmap);
+                break;
+        case POWER_SUPPLY_PROP_CHARGE_TYPE:
+                val->intval = max77693_get_charge_type(regmap);
+                break;
+        case POWER_SUPPLY_PROP_HEALTH:
+                val->intval = max77693_get_battery_health(regmap);
+                break;
+        case POWER_SUPPLY_PROP_PRESENT:
+                val->intval = max77693_get_present(regmap);
+                break;
+        case POWER_SUPPLY_PROP_ONLINE:
+                val->intval = max77693_get_online(regmap);
+                break;
+        case POWER_SUPPLY_PROP_MODEL_NAME:
+                val->strval = max77693_charger_model;
+                break;
+        case POWER_SUPPLY_PROP_MANUFACTURER:
+                val->strval = max77693_charger_manufacturer;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return ret;
+}
+
+static ssize_t device_attr_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count,
+                int (*fn)(struct max77693_charger *, unsigned long))
+{
+        struct max77693_charger *chg = dev_get_drvdata(dev);
+        unsigned long val;
+        int ret;
+
+        ret = kstrtoul(buf, 10, &val);
+        if (ret)
+                return ret;
+
+        ret = fn(chg, val);
+        if (ret)
+                return ret;
+
+        return count;
+}
+
+static ssize_t fast_charge_timer_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct max77693_charger *chg = dev_get_drvdata(dev);
+        unsigned int data, val;
+        int ret;
+
+        ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_01,
+                        &data);
+        if (ret < 0)
+                return ret;
+
+        data &= CHG_CNFG_01_FCHGTIME_MASK;
+        data >>= CHG_CNFG_01_FCHGTIME_SHIFT;
+        switch (data) {
+        case 0x1 ... 0x7:
+                /* Starting from 4 hours, step by 2 hours */
+                val = 4 + (data - 1) * 2;
+                break;
+        case 0x0:
+        default:
+                val = 0;
+                break;
+        }
+
+        return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static int max77693_set_fast_charge_timer(struct max77693_charger *chg,
+                unsigned long hours)
+{
+        unsigned int data;
+
+        /*
+         * 0x00 - disable
+         * 0x01 - 4h
+         * 0x02 - 6h
+         * ...
+         * 0x07 - 16h
+         * Round down odd values.
+         */
+        switch (hours) {
+        case 4 ... 16:
+                data = (hours - 4) / 2 + 1;
+                break;
+        case 0:
+                /* Disable */
+                data = 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+        data <<= CHG_CNFG_01_FCHGTIME_SHIFT;
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_01,
+                        CHG_CNFG_01_FCHGTIME_MASK, data);
+}
+
+static ssize_t fast_charge_timer_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count)
+{
+        return device_attr_store(dev, attr, buf, count,
+                        max77693_set_fast_charge_timer);
+}
+
+static ssize_t top_off_threshold_current_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct max77693_charger *chg = dev_get_drvdata(dev);
+        unsigned int data, val;
+        int ret;
+
+        ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
+                        &data);
+        if (ret < 0)
+                return ret;
+
+        data &= CHG_CNFG_03_TOITH_MASK;
+        data >>= CHG_CNFG_03_TOITH_SHIFT;
+
+        if (data <= 0x04)
+                val = 100000 + data * 25000;
+        else
+                val = data * 50000;
+
+        return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static int max77693_set_top_off_threshold_current(struct max77693_charger *chg,
+                unsigned long uamp)
+{
+        unsigned int data;
+
+        if (uamp < 100000 || uamp > 350000)
+                return -EINVAL;
+
+        if (uamp <= 200000)
+                data = (uamp - 100000) / 25000;
+        else
+                /* (200000, 350000> */
+                data = uamp / 50000;
+
+        data <<= CHG_CNFG_03_TOITH_SHIFT;
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_03,
+                        CHG_CNFG_03_TOITH_MASK, data);
+}
+
+static ssize_t top_off_threshold_current_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count)
+{
+        return device_attr_store(dev, attr, buf, count,
+                        max77693_set_top_off_threshold_current);
+}
+
+static ssize_t top_off_timer_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct max77693_charger *chg = dev_get_drvdata(dev);
+        unsigned int data, val;
+        int ret;
+
+        ret = regmap_read(chg->max77693->regmap, MAX77693_CHG_REG_CHG_CNFG_03,
+                        &data);
+        if (ret < 0)
+                return ret;
+
+        data &= CHG_CNFG_03_TOTIME_MASK;
+        data >>= CHG_CNFG_03_TOTIME_SHIFT;
+
+        val = data * 10;
+
+        return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static int max77693_set_top_off_timer(struct max77693_charger *chg,
+                unsigned long minutes)
+{
+        unsigned int data;
+
+        if (minutes > 70)
+                return -EINVAL;
+
+        data = minutes / 10;
+        data <<= CHG_CNFG_03_TOTIME_SHIFT;
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_03,
+                        CHG_CNFG_03_TOTIME_MASK, data);
+}
+
+static ssize_t top_off_timer_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t count)
+{
+        return device_attr_store(dev, attr, buf, count,
+                        max77693_set_top_off_timer);
+}
+
+static DEVICE_ATTR_RW(fast_charge_timer);
+static DEVICE_ATTR_RW(top_off_threshold_current);
+static DEVICE_ATTR_RW(top_off_timer);
+
+static int max77693_set_constant_volt(struct max77693_charger *chg,
+                unsigned int uvolt)
+{
+        unsigned int data;
+
+        /*
+         * 0x00 - 3.650 V
+         * 0x01 - 3.675 V
+         * ...
+         * 0x1b - 4.325 V
+         * 0x1c - 4.340 V
+         * 0x1d - 4.350 V
+         * 0x1e - 4.375 V
+         * 0x1f - 4.400 V
+         */
+        if (uvolt >= 3650000 && uvolt < 4340000)
+                data = (uvolt - 3650000) / 25000;
+        else if (uvolt >= 4340000 && uvolt < 4350000)
+                data = 0x1c;
+        else if (uvolt >= 4350000 && uvolt <= 4400000)
+                data = 0x1d + (uvolt - 4350000) / 25000;
+        else {
+                dev_err(chg->dev, "Wrong value for charging constant voltage\n");
+                return -EINVAL;
+        }
+
+        data <<= CHG_CNFG_04_CHGCVPRM_SHIFT;
+
+        dev_dbg(chg->dev, "Charging constant voltage: %u (0x%x)\n", uvolt,
+                        data);
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_04,
+                        CHG_CNFG_04_CHGCVPRM_MASK, data);
+}
+
+static int max77693_set_min_system_volt(struct max77693_charger *chg,
+                unsigned int uvolt)
+{
+        unsigned int data;
+
+        if (uvolt < 3000000 || uvolt > 3700000) {
+                dev_err(chg->dev, "Wrong value for minimum system regulation voltage\n");
+                return -EINVAL;
+        }
+
+        data = (uvolt - 3000000) / 100000;
+
+        data <<= CHG_CNFG_04_MINVSYS_SHIFT;
+
+        dev_dbg(chg->dev, "Minimum system regulation voltage: %u (0x%x)\n",
+                        uvolt, data);
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_04,
+                        CHG_CNFG_04_MINVSYS_MASK, data);
+}
+
+static int max77693_set_thermal_regulation_temp(struct max77693_charger *chg,
+                unsigned int cels)
+{
+        unsigned int data;
+
+        switch (cels) {
+        case 70:
+        case 85:
+        case 100:
+        case 115:
+                data = (cels - 70) / 15;
+                break;
+        default:
+                dev_err(chg->dev, "Wrong value for thermal regulation loop temperature\n");
+                return -EINVAL;
+        }
+
+        data <<= CHG_CNFG_07_REGTEMP_SHIFT;
+
+        dev_dbg(chg->dev, "Thermal regulation loop temperature: %u (0x%x)\n",
+                        cels, data);
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_07,
+                        CHG_CNFG_07_REGTEMP_MASK, data);
+}
+
+static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
+                unsigned int uamp)
+{
+        unsigned int data;
+
+        if (uamp && (uamp < 2000000 || uamp > 3500000)) {
+                dev_err(chg->dev, "Wrong value for battery overcurrent\n");
+                return -EINVAL;
+        }
+
+        if (uamp)
+                data = ((uamp - 2000000) / 250000) + 1;
+        else
+                data = 0; /* disable */
+
+        data <<= CHG_CNFG_12_B2SOVRC_SHIFT;
+
+        dev_dbg(chg->dev, "Battery overcurrent: %u (0x%x)\n", uamp, data);
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_12,
+                        CHG_CNFG_12_B2SOVRC_MASK, data);
+}
+
+static int max77693_set_charge_input_threshold_volt(struct max77693_charger *chg,
+                unsigned int uvolt)
+{
+        unsigned int data;
+
+        switch (uvolt) {
+        case 4300000:
+                data = 0x0;
+                break;
+        case 4700000:
+        case 4800000:
+        case 4900000:
+                data = (uvolt - 4700000) / 100000;
+        default:
+                dev_err(chg->dev, "Wrong value for charge input voltage regulation threshold\n");
+                return -EINVAL;
+        }
+
+        data <<= CHG_CNFG_12_VCHGINREG_SHIFT;
+
+        dev_dbg(chg->dev, "Charge input voltage regulation threshold: %u (0x%x)\n",
+                        uvolt, data);
+
+        return regmap_update_bits(chg->max77693->regmap,
+                        MAX77693_CHG_REG_CHG_CNFG_12,
+                        CHG_CNFG_12_VCHGINREG_MASK, data);
+}
+
+/*
+ * Sets charger registers to proper and safe default values.
+ */
+static int max77693_reg_init(struct max77693_charger *chg)
+{
+        int ret;
+        unsigned int data;
+
+        /* Unlock charger register protection */
+        data = (0x3 << CHG_CNFG_06_CHGPROT_SHIFT);
+        ret = regmap_update_bits(chg->max77693->regmap,
+                                MAX77693_CHG_REG_CHG_CNFG_06,
+                                CHG_CNFG_06_CHGPROT_MASK, data);
+        if (ret) {
+                dev_err(chg->dev, "Error unlocking registers: %d\n", ret);
+                return ret;
+        }
+
+        ret = max77693_set_fast_charge_timer(chg, DEFAULT_FAST_CHARGE_TIMER);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_top_off_threshold_current(chg,
+                        DEFAULT_TOP_OFF_THRESHOLD_CURRENT);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_top_off_timer(chg, DEFAULT_TOP_OFF_TIMER);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_constant_volt(chg, chg->constant_volt);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_min_system_volt(chg, chg->min_system_volt);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_thermal_regulation_temp(chg,
+                        chg->thermal_regulation_temp);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_batttery_overcurrent(chg, chg->batttery_overcurrent);
+        if (ret)
+                return ret;
+
+        ret = max77693_set_charge_input_threshold_volt(chg,
+                        chg->charge_input_threshold_volt);
+        if (ret)
+                return ret;
+
+        return 0;
+}
+
+#ifdef CONFIG_OF
+static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
+{
+        struct device_node *np = dev->of_node;
+
+        if (!np) {
+                dev_err(dev, "no charger OF node\n");
+                return -EINVAL;
+        }
+
+        if (of_property_read_u32(np, "maxim,constant-microvolt",
+                        &chg->constant_volt))
+                chg->constant_volt = DEFAULT_CONSTANT_VOLT;
+
+        if (of_property_read_u32(np, "maxim,min-system-microvolt",
+                        &chg->min_system_volt))
+                chg->min_system_volt = DEFAULT_MIN_SYSTEM_VOLT;
+
+        if (of_property_read_u32(np, "maxim,thermal-regulation-celsius",
+                        &chg->thermal_regulation_temp))
+                chg->thermal_regulation_temp = DEFAULT_THERMAL_REGULATION_TEMP;
+
+        if (of_property_read_u32(np, "maxim,battery-overcurrent-microamp",
+                        &chg->batttery_overcurrent))
+                chg->batttery_overcurrent = DEFAULT_BATTERY_OVERCURRENT;
+
+        if (of_property_read_u32(np, "maxim,charge-input-threshold-microvolt",
+                        &chg->charge_input_threshold_volt))
+                chg->charge_input_threshold_volt =
+                        DEFAULT_CHARGER_INPUT_THRESHOLD_VOLT;
+
+        return 0;
+}
+#else /* CONFIG_OF */
+static int max77693_dt_init(struct device *dev, struct max77693_charger *chg)
+{
+        return 0;
+}
+#endif /* CONFIG_OF */
+
+static int max77693_charger_probe(struct platform_device *pdev)
+{
+        struct max77693_charger *chg;
+        struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
+        int ret;
+
+        chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
+        if (!chg)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, chg);
+        chg->dev = &pdev->dev;
+        chg->max77693 = max77693;
+
+        ret = max77693_dt_init(&pdev->dev, chg);
+        if (ret)
+                return ret;
+
+        ret = max77693_reg_init(chg);
+        if (ret)
+                return ret;
+
+        chg->charger.name = max77693_charger_name;
+        chg->charger.type = POWER_SUPPLY_TYPE_BATTERY;
+        chg->charger.properties = max77693_charger_props;
+        chg->charger.num_properties = ARRAY_SIZE(max77693_charger_props);
+        chg->charger.get_property = max77693_charger_get_property;
+
+        ret = device_create_file(&pdev->dev, &dev_attr_fast_charge_timer);
+        if (ret) {
+                dev_err(&pdev->dev, "failed: create fast charge timer sysfs entry\n");
+                goto err;
+        }
+
+        ret = device_create_file(&pdev->dev,
+                        &dev_attr_top_off_threshold_current);
+        if (ret) {
+                dev_err(&pdev->dev, "failed: create top off current sysfs entry\n");
+                goto err;
+        }
+
+        ret = device_create_file(&pdev->dev, &dev_attr_top_off_timer);
+        if (ret) {
+                dev_err(&pdev->dev, "failed: create top off timer sysfs entry\n");
+                goto err;
+        }
+
+        ret = power_supply_register(&pdev->dev, &chg->charger);
+        if (ret) {
+                dev_err(&pdev->dev, "failed: power supply register\n");
+                goto err;
+        }
+
+        return 0;
+
+err:
+        device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
+        device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
+        device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
+
+        return ret;
+}
+
+static int max77693_charger_remove(struct platform_device *pdev)
+{
+        struct max77693_charger *chg = platform_get_drvdata(pdev);
+
+        device_remove_file(&pdev->dev, &dev_attr_top_off_timer);
+        device_remove_file(&pdev->dev, &dev_attr_top_off_threshold_current);
+        device_remove_file(&pdev->dev, &dev_attr_fast_charge_timer);
+
+        power_supply_unregister(&chg->charger);
+
+        return 0;
+}
+
+static const struct platform_device_id max77693_charger_id[] = {
+        { "max77693-charger", 0, },
+        { }
+};
+MODULE_DEVICE_TABLE(platform, max77693_charger_id);
+
+static struct platform_driver max77693_charger_driver = {
+        .driver = {
+                .owner  = THIS_MODULE,
+                .name   = "max77693-charger",
+        },
+        .probe          = max77693_charger_probe,
+        .remove         = max77693_charger_remove,
+        .id_table       = max77693_charger_id,
+};
+module_platform_driver(max77693_charger_driver);
+
+MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
+MODULE_DESCRIPTION("Maxim 77693 charger driver");
+MODULE_LICENSE("GPL");