[PATCH v4 11/27] power: supply: max77705: Add charger driver for Maxim 77705

[Dzmitry Sankouski <dsankouski@gmail.com>]

Add driver for Maxim 77705 switch-mode charger (part of max77705
MFD driver) providing power supply class information to userspace.

The driver is configured through DTS (battery and system related
settings).

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>

---
Changes for V4:
- start from scratch
- change word delimiters in filenames to '_'
- use GENMASK in header
- remove debugfs code
- migrate to regmap_add_irq_chip
- fix property getters to follow the same style
---
 drivers/power/supply/Kconfig            |   6 +
 drivers/power/supply/Makefile           |   1 +
 drivers/power/supply/max77705_charger.c | 585 ++++++++++++++++++++++++++++++++
 include/linux/mfd/max77705_charger.h    | 215 ++++++++++++
 4 files changed, 807 insertions(+)

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index bcfa63fb9f1e..fe84d2004f57 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -573,6 +573,12 @@ config CHARGER_MAX77693
 	help
 	  Say Y to enable support for the Maxim MAX77693 battery charger.
 
+config CHARGER_MAX77705
+	tristate "Maxim MAX77705 battery charger driver"
+	depends on MFD_MAX77705
+	help
+	  Say Y to enable support for the Maxim MAX77705 battery charger.
+
 config CHARGER_MAX77976
 	tristate "Maxim MAX77976 battery charger driver"
 	depends on I2C
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 8dcb41545317..daa9228fa04b 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -79,6 +79,7 @@ obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o
 obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o
 obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o
 obj-$(CONFIG_CHARGER_MAX77693)	+= max77693_charger.o
+obj-$(CONFIG_CHARGER_MAX77705)	+= max77705_charger.o
 obj-$(CONFIG_CHARGER_MAX77976)	+= max77976_charger.o
 obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
diff --git a/drivers/power/supply/max77705_charger.c b/drivers/power/supply/max77705_charger.c
new file mode 100644
index 000000000000..2d82c6663002
--- /dev/null
+++ b/drivers/power/supply/max77705_charger.c
@@ -0,0 +1,585 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Based on max77650-charger.c:
+//   Copyright (C) 2018 BayLibre SAS
+//   Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+//
+// Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail.org>
+//
+// Battery charger driver for MAXIM 77705 charger/power-supply.
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/max77693-common.h>
+#include <linux/mfd/max77705-private.h>
+#include <linux/mfd/max77705_charger.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+static const char *max77705_charger_model		= "max77705";
+static const char *max77705_charger_manufacturer	= "Maxim Integrated";
+
+static enum power_supply_property max77705_charger_props[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+};
+
+static int max77705_chgin_irq(void *irq_drv_data)
+{
+	struct max77705_charger_data *charger = irq_drv_data;
+
+	queue_work(charger->wqueue, &charger->chgin_work);
+
+	return 0;
+}
+
+static const struct regmap_irq max77705_charger_irqs[] = {
+	{ .mask = MAX77705_BYP_IM,   },
+	{ .mask = MAX77705_INP_LIMIT_IM,   },
+	{ .mask = MAX77705_BATP_IM,   },
+	{ .mask = MAX77705_BAT_IM,   },
+	{ .mask = MAX77705_CHG_IM,   },
+	{ .mask = MAX77705_WCIN_IM,   },
+	{ .mask = MAX77705_CHGIN_IM,   },
+	{ .mask = MAX77705_AICL_IM,   },
+};
+
+static const struct regmap_irq_chip max77705_charger_irq_chip = {
+	.name			= "max77705-charger",
+	.status_base		= MAX77705_CHG_REG_INT,
+	.mask_base		= MAX77705_CHG_REG_INT_MASK,
+	.handle_post_irq	= max77705_chgin_irq,
+	.num_regs		= 1,
+	.irqs			= max77705_charger_irqs,
+	.num_irqs		= ARRAY_SIZE(max77705_charger_irqs),
+};
+
+static int max77705_charger_enable(struct max77705_charger_data *chg)
+{
+	int rv;
+
+	rv = regmap_update_bits(chg->regmap, MAX77705_CHG_REG_CNFG_09,
+				MAX77705_CHG_EN_MASK, MAX77705_CHG_EN_MASK);
+	if (rv)
+		dev_err(chg->dev, "unable to enable the charger: %d\n", rv);
+
+	return rv;
+}
+
+static void max77705_charger_disable(struct max77705_charger_data *chg)
+{
+	int rv;
+
+	rv = regmap_update_bits(chg->regmap,
+				MAX77705_CHG_REG_CNFG_09,
+				MAX77705_CHG_EN_MASK,
+				MAX77705_CHG_DISABLE);
+	if (rv)
+		dev_err(chg->dev, "unable to disable the charger: %d\n", rv);
+}
+
+static int max77705_get_online(struct regmap *regmap, int *val)
+{
+	unsigned int data;
+	int ret;
+
+	ret = regmap_read(regmap, MAX77705_CHG_REG_INT_OK, &data);
+	if (ret < 0)
+		return ret;
+
+	*val = !!(data & MAX77705_CHGIN_OK);
+
+	return 0;
+}
+
+static int max77705_check_battery(struct max77705_charger_data *charger, int *val)
+{
+	unsigned int reg_data;
+	unsigned int reg_data2;
+	struct regmap *regmap = charger->regmap;
+
+
+	regmap_read(regmap, MAX77705_CHG_REG_INT_OK, &reg_data);
+
+	dev_dbg(charger->dev, "CHG_INT_OK(0x%x)\n", reg_data);
+
+	regmap_read(regmap,
+			  MAX77705_CHG_REG_DETAILS_00, &reg_data2);
+
+	dev_dbg(charger->dev, "CHG_DETAILS00(0x%x)\n", reg_data2);
+
+	if ((reg_data & MAX77705_BATP_OK) || !(reg_data2 & MAX77705_BATP_DTLS))
+		*val = true;
+	else
+		*val = false;
+
+	return 0;
+}
+
+static int max77705_get_charge_type(struct max77705_charger_data *charger, int *val)
+{
+	struct regmap *regmap = charger->regmap;
+	unsigned int reg_data;
+
+	regmap_read(regmap, MAX77705_CHG_REG_CNFG_09, &reg_data);
+	if (!MAX77705_CHARGER_CHG_CHARGING(reg_data)) {
+		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		return 0;
+	}
+
+	regmap_read(regmap, MAX77705_CHG_REG_DETAILS_01, &reg_data);
+	reg_data &= MAX77705_CHG_DTLS;
+
+	switch (reg_data) {
+	case 0x0:
+	case MAX77705_CHARGER_CONSTANT_CURRENT:
+	case MAX77705_CHARGER_CONSTANT_VOLTAGE:
+		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
+		return 0;
+	default:
+		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		return 0;
+	}
+
+	return 0;
+}
+
+static int max77705_get_status(struct max77705_charger_data *charger, int *val)
+{
+	struct regmap *regmap = charger->regmap;
+	unsigned int reg_data;
+
+	regmap_read(regmap, MAX77705_CHG_REG_CNFG_09, &reg_data);
+	if (!MAX77705_CHARGER_CHG_CHARGING(reg_data)) {
+		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
+		return 0;
+	}
+
+	regmap_read(regmap, MAX77705_CHG_REG_DETAILS_01, &reg_data);
+	reg_data &= MAX77705_CHG_DTLS;
+
+	switch (reg_data) {
+	case 0x0:
+	case MAX77705_CHARGER_CONSTANT_CURRENT:
+	case MAX77705_CHARGER_CONSTANT_VOLTAGE:
+		*val = POWER_SUPPLY_STATUS_CHARGING;
+		return 0;
+	case MAX77705_CHARGER_END_OF_CHARGE:
+	case MAX77705_CHARGER_DONE:
+		*val = POWER_SUPPLY_STATUS_FULL;
+		return 0;
+	// those values hard coded as in vendor kernel, because of
+	// failure to determine it's actual meaning.
+	case 0x05:
+	case 0x06:
+	case 0x07:
+		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		return 0;
+	case 0x08:
+	case 0xA:
+	case 0xB:
+		*val = POWER_SUPPLY_STATUS_DISCHARGING;
+		return 0;
+	default:
+		*val = POWER_SUPPLY_STATUS_UNKNOWN;
+		return 0;
+	}
+
+	return 0;
+}
+
+static int max77705_get_vbus_state(struct regmap *regmap, int *value)
+{
+	int ret;
+	unsigned int charge_dtls;
+
+	ret = regmap_read(regmap, MAX77705_CHG_REG_DETAILS_00, &charge_dtls);
+	if (ret)
+		return ret;
+
+	charge_dtls = ((charge_dtls & MAX77705_CHGIN_DTLS) >>
+			MAX77705_CHGIN_DTLS_SHIFT);
+
+	switch (charge_dtls) {
+	case 0x00:
+		*value = POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
+		break;
+	case 0x01:
+		*value = POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
+		break;
+	case 0x02:
+		*value = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		break;
+	case 0x03:
+		*value = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	default:
+		return 0;
+	}
+	return 0;
+}
+
+static int max77705_get_battery_health(struct max77705_charger_data *charger,
+					int *value)
+{
+	struct regmap *regmap = charger->regmap;
+	unsigned int bat_dtls;
+
+	regmap_read(regmap, MAX77705_CHG_REG_DETAILS_01, &bat_dtls);
+	bat_dtls = ((bat_dtls & MAX77705_BAT_DTLS) >> MAX77705_BAT_DTLS_SHIFT);
+
+	switch (bat_dtls) {
+	case MAX77705_BATTERY_NOBAT:
+		dev_dbg(charger->dev, "%s: No battery and the charger is suspended\n",
+			__func__);
+		*value = POWER_SUPPLY_HEALTH_NO_BATTERY;
+		break;
+	case MAX77705_BATTERY_PREQUALIFICATION:
+		dev_dbg(charger->dev, "%s: battery is okay but its voltage is low(~VPQLB)\n",
+			__func__);
+		break;
+	case MAX77705_BATTERY_DEAD:
+		dev_dbg(charger->dev, "%s: battery dead\n", __func__);
+		*value = POWER_SUPPLY_HEALTH_DEAD;
+		break;
+	case MAX77705_BATTERY_GOOD:
+	case MAX77705_BATTERY_LOWVOLTAGE:
+		*value = POWER_SUPPLY_HEALTH_GOOD;
+		break;
+	case MAX77705_BATTERY_OVERVOLTAGE:
+		dev_dbg(charger->dev, "%s: battery ovp\n", __func__);
+		*value = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		break;
+	default:
+		dev_dbg(charger->dev, "%s: battery unknown\n", __func__);
+		*value = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		break;
+	}
+
+	return 0;
+}
+
+static int max77705_get_health(struct max77705_charger_data *charger, int *val)
+{
+	struct regmap *regmap = charger->regmap;
+	int ret, is_online = 0;
+
+	ret = max77705_get_online(regmap, &is_online);
+	if (ret)
+		return ret;
+	if (is_online) {
+		ret = max77705_get_vbus_state(regmap, val);
+		if (ret || (*val != POWER_SUPPLY_HEALTH_GOOD))
+			return ret;
+	}
+	return max77705_get_battery_health(charger, val);
+}
+
+static int max77705_get_input_current(struct max77705_charger_data *charger,
+					int *val)
+{
+	unsigned int reg_data;
+	int get_current = 0;
+	struct regmap *regmap = charger->regmap;
+
+	regmap_read(regmap,
+			  MAX77705_CHG_REG_CNFG_09, &reg_data);
+
+	reg_data &= MAX77705_CHG_CHGIN_LIM_MASK;
+
+	if (reg_data <= 3)
+		get_current = 100;
+	else if (reg_data >= MAX77705_CHG_CHGIN_LIM_MASK)
+		get_current = MAX77705_CURRENT_CHGIN_MAX;
+	else
+		get_current = (reg_data + 1) * 25;
+
+	*val = get_current;
+
+	return 0;
+}
+
+static int max77705_get_charge_current(struct max77705_charger_data *charger,
+					int *val)
+{
+	unsigned int reg_data;
+	struct regmap *regmap = charger->regmap;
+
+
+	regmap_read(regmap, MAX77705_CHG_REG_CNFG_02, &reg_data);
+	reg_data &= MAX77705_CHG_CC;
+
+	*val = reg_data <= 0x2 ? 100 : reg_data * 50;
+
+	return 0;
+}
+
+static int max77705_set_float_voltage(struct max77705_charger_data *charger,
+					int float_voltage)
+{
+	int float_voltage_mv;
+	unsigned int reg_data = 0;
+	struct regmap *regmap = charger->regmap;
+
+	float_voltage_mv = float_voltage / 1000;
+	reg_data = float_voltage_mv <= 4000 ? 0x0 :
+		float_voltage_mv >= 4500 ? 0x23 :
+		(float_voltage_mv <= 4200) ? (float_voltage_mv - 4000) / 50 :
+		(((float_voltage_mv - 4200) / 10) + 0x04);
+
+	return regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_04,
+				MAX77705_CHG_CV_PRM_MASK,
+				(reg_data << MAX77705_CHG_CV_PRM_SHIFT));
+}
+
+static int max77705_get_float_voltage(struct max77705_charger_data *charger,
+					int *val)
+{
+	unsigned int reg_data = 0;
+	struct regmap *regmap = charger->regmap;
+
+	regmap_read(regmap, MAX77705_CHG_REG_CNFG_04, &reg_data);
+	reg_data &= MAX77705_CHG_PRM_MASK;
+	*val = reg_data <= 0x04 ? reg_data * 50 + 4000 :
+					(reg_data - 4) * 10 + 4200;
+
+	return 0;
+}
+
+static int max77705_chg_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct max77705_charger_data *charger = power_supply_get_drvdata(psy);
+	struct regmap *regmap = charger->regmap;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		return max77705_get_online(regmap, &val->intval);
+	case POWER_SUPPLY_PROP_PRESENT:
+		return max77705_check_battery(charger, &val->intval);
+	case POWER_SUPPLY_PROP_STATUS:
+		return max77705_get_status(charger, &val->intval);
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		return max77705_get_charge_type(charger, &val->intval);
+	case POWER_SUPPLY_PROP_HEALTH:
+		return max77705_get_health(charger, &val->intval);
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		return max77705_get_input_current(charger, &val->intval);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return max77705_get_charge_current(charger, &val->intval);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return max77705_get_float_voltage(charger, &val->intval);
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+		val->intval = charger->bat_info->voltage_max_design_uv;
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = max77705_charger_model;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = max77705_charger_manufacturer;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static const struct power_supply_desc max77705_charger_psy_desc = {
+	.name = "max77705-charger",
+	.type		= POWER_SUPPLY_TYPE_USB,
+	.properties = max77705_charger_props,
+	.num_properties = ARRAY_SIZE(max77705_charger_props),
+	.get_property = max77705_chg_get_property,
+};
+
+static void max77705_chgin_isr_work(struct work_struct *work)
+{
+	struct max77705_charger_data *charger =
+		container_of(work, struct max77705_charger_data, chgin_work);
+	power_supply_changed(charger->psy_chg);
+}
+
+static void max77705_charger_initialize(struct max77705_charger_data *chg)
+{
+	u8 reg_data;
+	struct power_supply_battery_info *info;
+	struct regmap *regmap = chg->regmap;
+
+	if (power_supply_get_battery_info(chg->psy_chg, &info) < 0)
+		return;
+
+	chg->bat_info = info;
+
+	// unlock charger setting protect
+	// slowest LX slope
+	reg_data = MAX77705_CHGPROT_MASK | MAX77705_SLOWEST_LX_SLOPE;
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_06, reg_data,
+						reg_data);
+
+	// fast charge timer disable
+	// restart threshold disable
+	// pre-qual charge disable
+	reg_data = (MAX77705_FCHGTIME_DISABLE << MAX77705_FCHGTIME_SHIFT) |
+			(MAX77705_CHG_RSTRT_DISABLE << MAX77705_CHG_RSTRT_SHIFT) |
+			(MAX77705_CHG_PQEN_DISABLE << MAX77705_PQEN_SHIFT);
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_01,
+						(MAX77705_FCHGTIME_MASK |
+						MAX77705_CHG_RSTRT_MASK |
+						MAX77705_PQEN_MASK),
+						reg_data);
+
+	// OTG off(UNO on), boost off
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_00,
+				MAX77705_OTG_CTRL, 0);
+
+	// charge current 450mA(default)
+	// otg current limit 900mA
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_02,
+				MAX77705_OTG_ILIM_MASK,
+				MAX77705_OTG_ILIM_900 << MAX77705_OTG_ILIM_SHIFT);
+
+	// BAT to SYS OCP 4.80A
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_05,
+				MAX77705_REG_B2SOVRC_MASK,
+				MAX77705_B2SOVRC_4_8A << MAX77705_REG_B2SOVRC_SHIFT);
+	// top off current 150mA
+	// top off timer 30min
+	reg_data = (MAX77705_TO_ITH_150MA << MAX77705_TO_ITH_SHIFT) |
+			(MAX77705_TO_TIME_30M << MAX77705_TO_TIME_SHIFT) |
+			(MAX77705_SYS_TRACK_DISABLE << MAX77705_SYS_TRACK_DIS_SHIFT);
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_03,
+			   (MAX77705_TO_ITH_MASK |
+			   MAX77705_TO_TIME_MASK |
+			   MAX77705_SYS_TRACK_DIS_MASK), reg_data);
+
+	// cv voltage 4.2V or 4.35V
+	// MINVSYS 3.6V(default)
+	if (info->voltage_max_design_uv < 0) {
+		dev_warn(chg->dev, "missing battery:voltage-max-design-microvolt\n");
+		max77705_set_float_voltage(chg, 4200000);
+	} else {
+		max77705_set_float_voltage(chg, info->voltage_max_design_uv);
+	}
+
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_12,
+				MAX77705_VCHGIN_REG_MASK, MAX77705_VCHGIN_4_5);
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_12,
+				MAX77705_WCIN_REG_MASK, MAX77705_WCIN_4_5);
+
+	// Watchdog timer
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_00,
+				MAX77705_WDTEN_MASK, 0);
+
+	// Active Discharge Enable
+	regmap_update_bits(regmap, MAX77705_PMIC_REG_MAINCTRL1, 1, 1);
+
+	// VBYPSET=5.0V
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_11, MAX77705_VBYPSET_MASK, 0);
+
+	// Switching Frequency : 1.5MHz
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_08, MAX77705_REG_FSW_MASK,
+				(MAX77705_CHG_FSW_1_5MHz << MAX77705_REG_FSW_SHIFT));
+
+	// Auto skip mode
+	regmap_update_bits(regmap, MAX77705_CHG_REG_CNFG_12, MAX77705_REG_DISKIP_MASK,
+				(MAX77705_AUTO_SKIP << MAX77705_REG_DISKIP_SHIFT));
+}
+
+static int max77705_charger_probe(struct platform_device *pdev)
+{
+	struct power_supply_config pscfg = {};
+	struct max77693_dev *max77705;
+	struct max77705_charger_data *chg;
+	struct device *dev, *parent;
+	struct regmap_irq_chip_data *irq_data;
+	int ret;
+
+	dev = &pdev->dev;
+	parent = dev->parent;
+	max77705 = dev_get_drvdata(parent);
+
+	chg = devm_kzalloc(dev, sizeof(*chg), GFP_KERNEL);
+	if (!chg)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, chg);
+
+	chg->regmap = max77705->regmap_chg;
+	if (!chg->regmap)
+		return -ENODEV;
+
+	chg->dev = dev;
+
+	max77705_charger_irq_chip.irq_drv_data = chg;
+	ret = devm_regmap_add_irq_chip(chg->dev, chg->regmap, max77705->irq,
+					IRQF_ONESHOT | IRQF_SHARED, 0,
+					&max77705_charger_irq_chip,
+					&irq_data);
+	if (ret) {
+		dev_err(dev, "failed to add irq chip: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_update_bits(chg->regmap,
+				MAX77705_CHG_REG_INT_MASK,
+				MAX77705_CHGIN_IM, 0);
+
+	if (ret)
+		return ret;
+
+	chg->wqueue = create_singlethread_workqueue(dev_name(dev));
+	if (IS_ERR(chg->wqueue)) {
+		dev_err(dev, "failed to create workqueue\n");
+		return PTR_ERR(chg->wqueue);
+	}
+	INIT_WORK(&chg->chgin_work, max77705_chgin_isr_work);
+
+	pscfg.of_node = dev->of_node;
+	pscfg.drv_data = chg;
+
+	chg->psy_chg = devm_power_supply_register(dev, &max77705_charger_psy_desc,
+						  &pscfg);
+	if (IS_ERR(chg->psy_chg))
+		return PTR_ERR(chg->psy_chg);
+
+	max77705_charger_initialize(chg);
+
+	return max77705_charger_enable(chg);
+}
+
+static void max77705_charger_remove(struct platform_device *pdev)
+{
+	struct max77705_charger_data *chg = platform_get_drvdata(pdev);
+
+	max77705_charger_disable(chg);
+}
+
+static const struct of_device_id max77705_charger_of_match[] = {
+	{ .compatible = "maxim,max77705-charger" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max77705_charger_of_match);
+
+static struct platform_driver max77705_charger_driver = {
+	.driver = {
+		.name = "max77705-charger",
+		.of_match_table = max77705_charger_of_match,
+	},
+	.probe = max77705_charger_probe,
+	.remove_new = max77705_charger_remove,
+};
+module_platform_driver(max77705_charger_driver);
+
+MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>");
+MODULE_DESCRIPTION("Maxim 77705 charger driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/max77705_charger.h b/include/linux/mfd/max77705_charger.h
new file mode 100644
index 000000000000..72614d7575a3
--- /dev/null
+++ b/include/linux/mfd/max77705_charger.h
@@ -0,0 +1,215 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+//
+// Maxim MAX77705 definitions.
+//
+// Copyright (C) 2015 Samsung Electronics, Inc.
+// Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail.com>
+
+#ifndef __MAX77705_CHARGER_H
+#define __MAX77705_CHARGER_H __FILE__
+
+// MAX77705_CHG_REG_CHG_INT
+#define MAX77705_BYP_I		BIT(0)
+#define MAX77705_INP_LIMIT_I	BIT(1)
+#define MAX77705_BATP_I		BIT(2)
+#define MAX77705_BAT_I		BIT(3)
+#define MAX77705_CHG_I		BIT(4)
+#define MAX77705_WCIN_I		BIT(5)
+#define MAX77705_CHGIN_I	BIT(6)
+#define MAX77705_AICL_I		BIT(7)
+
+// MAX77705_CHG_REG_CHG_INT_MASK
+#define MAX77705_BYP_IM		BIT(0)
+#define MAX77705_INP_LIMIT_IM	BIT(1)
+#define MAX77705_BATP_IM	BIT(2)
+#define MAX77705_BAT_IM		BIT(3)
+#define MAX77705_CHG_IM		BIT(4)
+#define MAX77705_WCIN_IM	BIT(5)
+#define MAX77705_CHGIN_IM	BIT(6)
+#define MAX77705_AICL_IM	BIT(7)
+
+// MAX77705_CHG_REG_CHG_INT_OK
+#define MAX77705_BYP_OK		BIT(0)
+#define MAX77705_DISQBAT_OK	BIT(1)
+#define MAX77705_BATP_OK	BIT(2)
+#define MAX77705_BAT_OK		BIT(3)
+#define MAX77705_CHG_OK		BIT(4)
+#define MAX77705_WCIN_OK	BIT(5)
+#define MAX77705_CHGIN_OK	BIT(6)
+#define MAX77705_AICL_OK	BIT(7)
+
+// MAX77705_CHG_REG_DETAILS_00
+#define MAX77705_BATP_DTLS		BIT(0)
+#define MAX77705_WCIN_DTLS		GENMASK(4, 3)
+#define MAX77705_WCIN_DTLS_SHIFT	3
+#define MAX77705_CHGIN_DTLS		GENMASK(6, 5)
+#define MAX77705_CHGIN_DTLS_SHIFT	5
+
+// MAX77705_CHG_REG_DETAILS_01
+#define MAX77705_CHG_DTLS	GENMASK(3, 0)
+#define MAX77705_CHG_DTLS_SHIFT	0
+#define MAX77705_BAT_DTLS	GENMASK(6, 4)
+#define MAX77705_BAT_DTLS_SHIFT	4
+
+// MAX77705_CHG_REG_DETAILS_02
+#define MAX77705_BYP_DTLS	GENMASK(3, 0)
+#define MAX77705_BYP_DTLS_SHIFT	0
+
+// MAX77705_CHG_REG_CNFG_00
+#define MAX77705_CHG_SHIFT	0
+#define MAX77705_UNO_SHIFT	1
+#define MAX77705_OTG_SHIFT	1
+#define MAX77705_BUCK_SHIFT	2
+#define MAX77705_BOOST_SHIFT	3
+#define MAX77705_WDTEN_SHIFT	4
+#define MAX77705_MODE_MASK	GENMASK(3, 0)
+#define MAX77705_CHG_MASK	BIT(MAX77705_CHG_SHIFT)
+#define MAX77705_UNO_MASK	BIT(MAX77705_UNO_SHIFT)
+#define MAX77705_OTG_MASK	BIT(MAX77705_OTG_SHIFT)
+#define MAX77705_BUCK_MASK	BIT(MAX77705_BUCK_SHIFT)
+#define MAX77705_BOOST_MASK	BIT(MAX77705_BOOST_SHIFT)
+#define MAX77705_WDTEN_MASK	BIT(MAX77705_WDTEN_SHIFT)
+#define MAX77705_UNO_CTRL	(MAX77705_UNO_MASK | MAX77705_BOOST_MASK)
+#define MAX77705_OTG_CTRL	(MAX77705_OTG_MASK | MAX77705_BOOST_MASK)
+
+// MAX77705_CHG_REG_CNFG_01
+#define MAX77705_FCHGTIME_SHIFT		0
+#define MAX77705_FCHGTIME_MASK		GENMASK(2, 0)
+#define MAX77705_CHG_RSTRT_SHIFT	4
+#define MAX77705_CHG_RSTRT_MASK		GENMASK(5, 4)
+#define MAX77705_FCHGTIME_DISABLE	0
+#define MAX77705_CHG_RSTRT_DISABLE	0x3
+
+#define MAX77705_PQEN_SHIFT		7
+#define MAX77705_PQEN_MASK		BIT(7)
+#define MAX77705_CHG_PQEN_DISABLE	0
+#define MAX77705_CHG_PQEN_ENABLE	1
+
+// MAX77705_CHG_REG_CNFG_02
+#define MAX77705_OTG_ILIM_SHIFT		6
+#define MAX77705_OTG_ILIM_MASK		GENMASK(7, 6)
+#define MAX77705_OTG_ILIM_500		0
+#define MAX77705_OTG_ILIM_900		1
+#define MAX77705_OTG_ILIM_1200		2
+#define MAX77705_OTG_ILIM_1500		3
+#define MAX77705_CHG_CC			GENMASK(5, 0)
+
+// MAX77705_CHG_REG_CNFG_03
+#define MAX77705_TO_ITH_SHIFT		0
+#define MAX77705_TO_ITH_MASK		GENMASK(2, 0)
+#define MAX77705_TO_TIME_SHIFT		3
+#define MAX77705_TO_TIME_MASK		GENMASK(5, 3)
+#define MAX77705_SYS_TRACK_DIS_SHIFT	7
+#define MAX77705_SYS_TRACK_DIS_MASK	BIT(7)
+#define MAX77705_TO_ITH_150MA		0
+#define MAX77705_TO_TIME_30M		3
+#define MAX77705_SYS_TRACK_ENABLE	0
+#define MAX77705_SYS_TRACK_DISABLE	1
+
+// MAX77705_CHG_REG_CNFG_04
+#define MAX77705_CHG_MINVSYS_SHIFT	6
+#define MAX77705_CHG_MINVSYS_MASK	GENMASK(7, 6)
+#define MAX77705_CHG_PRM_SHIFT		0
+#define MAX77705_CHG_PRM_MASK		GENMASK(5, 0)
+
+#define MAX77705_CHG_CV_PRM_SHIFT	0
+#define MAX77705_CHG_CV_PRM_MASK	GENMASK(5, 0)
+
+// MAX77705_CHG_REG_CNFG_05
+#define MAX77705_REG_B2SOVRC_SHIFT	0
+#define MAX77705_REG_B2SOVRC_MASK	GENMASK(3, 0)
+#define MAX77705_B2SOVRC_DISABLE	0
+#define MAX77705_B2SOVRC_4_5A		6
+#define MAX77705_B2SOVRC_4_8A		8
+#define MAX77705_B2SOVRC_5_0A		9
+
+// MAX77705_CHG_CNFG_06
+#define MAX77705_WDTCLR_SHIFT		0
+#define MAX77705_WDTCLR_MASK		GENMASK(1, 0)
+#define MAX77705_WDTCLR			1
+#define MAX77705_CHGPROT_MASK		GENMASK(3, 2)
+#define MAX77705_CHGPROT_UNLOCKED	GENMASK(3, 2)
+#define MAX77705_SLOWEST_LX_SLOPE	GENMASK(6, 5)
+
+// MAX77705_CHG_REG_CNFG_07
+#define MAX77705_CHG_FMBST		4
+#define MAX77705_REG_FMBST_SHIFT	2
+#define MAX77705_REG_FMBST_MASK		BIT(MAX77705_REG_FMBST_SHIFT)
+#define MAX77705_REG_FGSRC_SHIFT	1
+#define MAX77705_REG_FGSRC_MASK		BIT(MAX77705_REG_FGSRC_SHIFT)
+
+// MAX77705_CHG_REG_CNFG_08
+#define MAX77705_REG_FSW_SHIFT		0
+#define MAX77705_REG_FSW_MASK		GENMASK(1, 0)
+#define MAX77705_CHG_FSW_3MHz		0
+#define MAX77705_CHG_FSW_2MHz		1
+#define MAX77705_CHG_FSW_1_5MHz		2
+
+// MAX77705_CHG_REG_CNFG_09
+#define MAX77705_CHG_CHGIN_LIM_MASK		GENMASK(6, 0)
+#define MAX77705_CHG_EN_MASK			BIT(7)
+#define MAX77705_CHG_DISABLE			0
+#define MAX77705_CHARGER_CHG_CHARGING(_reg) \
+				(((_reg) & MAX77705_CHG_EN_MASK) > 1)
+
+
+// MAX77705_CHG_REG_CNFG_10
+#define MAX77705_CHG_WCIN_LIM		GENMASK(5, 0)
+
+// MAX77705_CHG_REG_CNFG_11
+#define MAX77705_VBYPSET_SHIFT		0
+#define MAX77705_VBYPSET_MASK		GENMASK(6, 0)
+
+// MAX77705_CHG_REG_CNFG_12
+#define MAX77705_CHGINSEL_SHIFT		5
+#define MAX77705_CHGINSEL_MASK		BIT(MAX77705_CHGINSEL_SHIFT)
+#define MAX77705_WCINSEL_SHIFT		6
+#define MAX77705_WCINSEL_MASK		BIT(MAX77705_WCINSEL_SHIFT)
+#define MAX77705_VCHGIN_REG_MASK	GENMASK(4, 3)
+#define MAX77705_WCIN_REG_MASK		GENMASK(2, 1)
+#define MAX77705_REG_DISKIP_SHIFT	0
+#define MAX77705_REG_DISKIP_MASK	BIT(MAX77705_REG_DISKIP_SHIFT)
+// REG=4.5V, UVLO=4.7V
+#define MAX77705_VCHGIN_4_5		0
+// REG=4.5V, UVLO=4.7V
+#define MAX77705_WCIN_4_5		0
+#define MAX77705_DISABLE_SKIP		1
+#define MAX77705_AUTO_SKIP		0
+
+// mA
+#define MAX77705_CURRENT_STEP		25
+#define MAX77705_CURRENT_WCIN_MAX	1600
+#define MAX77705_CURRENT_CHGIN_MAX	3200
+
+/* Convert current in mA to corresponding CNFG09 value */
+inline u8 max77705_convert_ma_to_chgin_ilim_value(unsigned int cur)
+{
+	if (cur < MAX77705_CURRENT_STEP)
+		return 0;
+	if (cur < MAX77705_CURRENT_CHGIN_MAX)
+		return (cur / MAX77705_CURRENT_STEP) - 1;
+	else
+		return (MAX77705_CURRENT_CHGIN_MAX / MAX77705_CURRENT_STEP) - 1;
+}
+
+/* Convert current in mA to corresponding CNFG10 value */
+inline u8 max77705_convert_ma_to_wcin_ilim_value(unsigned int cur)
+{
+	if (cur < MAX77705_CURRENT_STEP)
+		return 0;
+	if (cur < MAX77705_CURRENT_WCIN_MAX)
+		return (cur / MAX77705_CURRENT_STEP) - 1;
+	else
+		return (MAX77705_CURRENT_WCIN_MAX / MAX77705_CURRENT_STEP) - 1;
+}
+
+struct max77705_charger_data {
+	struct device			*dev;
+	struct regmap		*regmap;
+	struct power_supply_battery_info *bat_info;
+	struct workqueue_struct *wqueue;
+	struct work_struct	chgin_work;
+	struct power_supply	*psy_chg;
+};
+
+#endif // __MAX77705_CHARGER_H

-- 
2.39.2