Message-Id: <20251123-max77759-charger-v1-5-6b2e4b8f7f54@google.com>
Date: Sun, 23 Nov 2025 08:35:52 +0000
From: Amit Sunil Dhamne via B4 Relay <devnull+amitsd.google.com@...nel.org>
To: Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, 
 André Draszik <andre.draszik@...aro.org>, 
 Lee Jones <lee@...nel.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 Badhri Jagan Sridharan <badhri@...gle.com>, 
 Heikki Krogerus <heikki.krogerus@...ux.intel.com>, 
 Peter Griffin <peter.griffin@...aro.org>, 
 Tudor Ambarus <tudor.ambarus@...aro.org>, 
 Alim Akhtar <alim.akhtar@...sung.com>
Cc: linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, 
 devicetree@...r.kernel.org, linux-usb@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, linux-samsung-soc@...r.kernel.org, 
 RD Babiera <rdbabiera@...gle.com>, Kyle Tso <kyletso@...gle.com>, 
 Amit Sunil Dhamne <amitsd@...gle.com>
Subject: [PATCH 5/6] power: supply: max77759: add charger driver

From: Amit Sunil Dhamne <amitsd@...gle.com>

Add support for MAX77759 battery charger driver. This is a 4A 1-Cell
Li+/LiPoly dual input switch mode charger. While the device can support
USB & wireless charger inputs, this implementation only supports USB
input. This implementation supports both buck and boost modes.

Signed-off-by: Amit Sunil Dhamne <amitsd@...gle.com>
---
 MAINTAINERS                             |   7 +
 drivers/mfd/max77759.c                  |   3 +-
 drivers/power/supply/Kconfig            |  11 +
 drivers/power/supply/Makefile           |   1 +
 drivers/power/supply/max77759_charger.c | 866 ++++++++++++++++++++++++++++++++
 5 files changed, 887 insertions(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index fed6cd812d79..f1b1015c08b5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15053,6 +15053,13 @@ F:	drivers/mfd/max77759.c
 F:	drivers/nvmem/max77759-nvmem.c
 F:	include/linux/mfd/max77759.h
 
+MAXIM MAX77759 BATTERY CHARGER DRIVER
+M:	Amit Sunil Dhamne <amitsd@...gle.com>
+L:	linux-kernel@...r.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/power/supply/maxim,max77759-charger.yaml
+F:	drivers/power/supply/max77759_charger.c
+
 MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER
 M:	Javier Martinez Canillas <javier@...hile0.org>
 L:	linux-kernel@...r.kernel.org
diff --git a/drivers/mfd/max77759.c b/drivers/mfd/max77759.c
index 5fe22884f362..8a22838be1b0 100644
--- a/drivers/mfd/max77759.c
+++ b/drivers/mfd/max77759.c
@@ -349,7 +349,8 @@ static const struct mfd_cell max77759_maxq_cells[] = {
 };
 
 static const struct mfd_cell max77759_charger_cells[] = {
-	MFD_CELL_RES("max77759-charger", max77759_charger_resources),
+	MFD_CELL_OF("max77759-charger", max77759_charger_resources, NULL, 0, 0,
+		    "maxim,max77759-charger"),
 };
 
 int max77759_maxq_command(struct max77759 *max77759,
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 79ddb006e2da..b97990cc0b92 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -1074,4 +1074,15 @@ config FUEL_GAUGE_MM8013
 	  the state of charge, temperature, cycle count, actual and design
 	  capacity, etc.
 
+config CHARGER_MAX77759
+	tristate "MAX77759 Charger Driver"
+	depends on MFD_MAX77759
+	default MFD_MAX77759
+	help
+	  Say M or Y here to enable the MAX77759 Charger Driver. MAX77759
+	  charger is a function of the MAX77759 PMIC. This is a dual input
+	  switch-mode charger. This driver supports buck and OTG boost modes.
+
+	  If built as a module, it will be called max77759_charger.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index f943c9150b32..12669734cfe3 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -122,3 +122,4 @@ obj-$(CONFIG_CHARGER_SURFACE)	+= surface_charger.o
 obj-$(CONFIG_BATTERY_UG3105)	+= ug3105_battery.o
 obj-$(CONFIG_CHARGER_QCOM_SMB2)	+= qcom_smbx.o
 obj-$(CONFIG_FUEL_GAUGE_MM8013)	+= mm8013.o
+obj-$(CONFIG_CHARGER_MAX77759)	+= max77759_charger.o
diff --git a/drivers/power/supply/max77759_charger.c b/drivers/power/supply/max77759_charger.c
new file mode 100644
index 000000000000..51637e87182b
--- /dev/null
+++ b/drivers/power/supply/max77759_charger.c
@@ -0,0 +1,866 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * max77759_charger.c - Battery charger driver for MAX77759 charger device.
+ *
+ * Copyright 2025 Google LLC.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/devm-helpers.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/math64.h>
+#include <linux/mfd/max77759.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/string_choices.h>
+
+/* CHG_INT_OK */
+#define CHG_INT_OK_AICL_OK			BIT(7)
+#define CHG_INT_OK_CHGIN_OK			BIT(6)
+#define CHG_INT_OK_CHG_OK			BIT(4)
+#define CHG_INT_OK_INLIM_OK			BIT(2)
+
+/* CHG_DETAILS_00 */
+#define CHG_DETAILS_OO_CHGIN_DTLS		GENMASK(6, 5)
+
+/*
+ * Charger Input Status
+ * @CHGIN_DTLS_VBUS_UNDERVOLTAGE: Charger input voltage (Vchgin) < Under Voltage
+ *     Threshold (Vuvlo)
+ * @CHGIN_DTLS_VBUS_MARGINAL_VOLTAGE: Vchgin > Vuvlo and
+ *     Vchgin < (Battery Voltage (Vbatt) + system voltage (Vsys))
+ * @CHGIN_DTLS_VBUS_OVERVOLTAGE: Vchgin > Over Voltage threshold (Vovlo)
+ * @CHGIN_DTLS_VBUS_VALID: Vchgin > Vuvlo, Vchgin < Vovlo and
+ *     Vchgin > (Vsys + Vbatt)
+ */
+enum chgin_dtls_status {
+	CHGIN_DTLS_VBUS_UNDERVOLTAGE,
+	CHGIN_DTLS_VBUS_MARGINAL_VOLTAGE,
+	CHGIN_DTLS_VBUS_OVERVOLTAGE,
+	CHGIN_DTLS_VBUS_VALID,
+};
+
+/* CHG_DETAILS_01 */
+#define CHG_DETAILS_01_BAT_DTLS			GENMASK(6, 4)
+
+/*
+ * Battery Details
+ * @BAT_DTLS_NO_BATT_CHG_SUSP:    No battery and the charger suspended
+ * @BAT_DTLS_DEAD_BATTERY:        Vbatt < Vtrickle
+ * @BAT_DTLS_BAT_CHG_TIMER_FAULT: Charging suspended due to timer fault
+ * @BAT_DTLS_BAT_OKAY: Battery okay and Vbatt > Min Sys Voltage (Vsysmin)
+ * @BAT_DTLS_BAT_UNDERVOLTAGE:    Battery is okay. Vtrickle < Vbatt < Vsysmin
+ * @BAT_DTLS_BAT_OVERVOLTAGE:     Battery voltage > Overvoltage threshold
+ * @BAT_DTLS_BAT_OVERCURRENT: Battery current exceeds overcurrent threshold
+ * @BAT_DTLS_BAT_ONLY_MODE:   Battery only mode and battery level not available
+ */
+enum bat_dtls_states {
+	BAT_DTLS_NO_BATT_CHG_SUSP,
+	BAT_DTLS_DEAD_BATTERY,
+	BAT_DTLS_BAT_CHG_TIMER_FAULT,
+	BAT_DTLS_BAT_OKAY,
+	BAT_DTLS_BAT_UNDERVOLTAGE,
+	BAT_DTLS_BAT_OVERVOLTAGE,
+	BAT_DTLS_BAT_OVERCURRENT,
+	BAT_DTLS_BAT_ONLY_MODE,
+};
+
+#define CHG_DETAILS_01_CHG_DTLS			GENMASK(3, 0)
+
+/*
+ * Charger Details
+ * @CHG_DTLS_PREQUAL: Charger in prequalification mode
+ * @CHG_DTLS_CC:      Charger in fast charge const curr mode
+ * @CHG_DTLS_CV:      Charger in fast charge const voltage mode
+ * @CHG_DTLS_TO:      Charger is in top off mode
+ * @CHG_DTLS_DONE:    Charger is done
+ * @CHG_DTLS_RSVD_1:  Reserved
+ * @CHG_DTLS_TIMER_FAULT:   Charger is in timer fault mode
+ * @CHG_DTLS_SUSP_BATT_THM: Charger is suspended as bettery removal detected
+ * @CHG_DTLS_OFF:     Charger is off. Input invalid or charger disabled
+ * @CHG_DTLS_RSVD_2:  Reserved
+ * @CHG_DTLS_RSVD_3:   Reserved
+ * @CHG_DTLS_OFF_WDOG_TIMER:    Charger is off as watchdog timer expired
+ * @CHG_DTLS_SUSP_JEITA:        Charger is in JEITA control mode
+ */
+enum chg_dtls_states {
+	CHG_DTLS_PREQUAL,
+	CHG_DTLS_CC,
+	CHG_DTLS_CV,
+	CHG_DTLS_TO,
+	CHG_DTLS_DONE,
+	CHG_DTLS_RSVD_1,
+	CHG_DTLS_TIMER_FAULT,
+	CHG_DTLS_SUSP_BATT_THM,
+	CHG_DTLS_OFF,
+	CHG_DTLS_RSVD_2,
+	CHG_DTLS_RSVD_3,
+	CHG_DTLS_OFF_WDOG_TIMER,
+	CHG_DTLS_SUSP_JEITA,
+};
+
+/* CHG_DETAILS_02 */
+#define CHG_DETAILS_02_CHGIN_STS		BIT(5)
+
+/* CHG_CNFG_00 */
+#define CHG_CNFG_00_MODE			GENMASK(3, 0)
+
+enum chg_mode {
+	CHG_MODE_OFF,
+	CHG_MODE_CHG_BUCK_ON = 0x5,
+	CHG_MODE_OTG_BOOST_ON = 0xA,
+};
+
+/* CHG_CNFG_02 */
+/* Fast Charge Current Selection (in uA) */
+#define CHG_CNFG_02_CHGCC			GENMASK(5, 0)
+#define CHGCC_LIMIT_MIN_UA			133330
+#define CHGCC_LIMIT_MAX_UA			4000000
+#define CHGCC_LIMIT_STEP_UA			66670
+#define CHGCC_LIMIT_REG_OFFSET			0x2
+
+/* CHG_CNFG_04 */
+/* Charge Termination Voltage Setting (in mV) */
+#define CHG_CNFG_04_CHG_CV_PRM			GENMASK(5, 0)
+/* [3.8, 3.9] V range */
+#define CHG_CV_PRM_LIMIT_LO_MIN_MV		3800
+#define CHG_CV_PRM_LIMIT_LO_MAX_MV		3900
+#define CHG_CV_PRM_LIMIT_LO_STEP_MV		100
+#define CHG_CV_PRM_LIMIT_LO_MIN_REG		0x38
+#define CHG_CV_PRM_LIMIT_LO_MAX_REG		0x39
+/* [4, 4.5] V range */
+#define CHG_CV_PRM_LIMIT_HI_MIN_MV		4000
+#define CHG_CV_PRM_LIMIT_HI_MAX_MV		4500
+#define CHG_CV_PRM_LIMIT_HI_STEP_MV		10
+#define CHG_CV_PRM_LIMIT_HI_MIN_REG		0x0
+#define CHG_CV_PRM_LIMIT_HI_MAX_REG		0x32
+
+/* CHG_CNFG_06 */
+#define CHG_CNFG_06_CHGPROT			GENMASK(3, 2)
+
+/* CHG_CNFG_09 */
+/* CHGIN Input Current Limit (in uA) */
+#define CHG_CNFG_09_CHGIN_ILIM			GENMASK(6, 0)
+#define CHGIN_ILIM_MIN_UA			100000
+#define CHGIN_ILIM_MAX_UA			3200000
+#define CHGIN_ILIM_STEP_UA			25000
+#define CHGIN_ILIM_REG_OFFSET			0x3
+
+/* CHG_CNFG_12 (Protected) */
+/* Wireless Charging input channel select */
+#define CHG_CNFG_12_WCINSEL			BIT(6)
+/* CHGIN/USB input channel select */
+#define CHG_CNFG_12_CHGINSEL			BIT(5)
+
+/* CHG_CNFG_18 (Protected) */
+/* Watchdog Timer Enable Bit */
+#define CHG_CNFG_18_WDTEN			BIT(0)
+
+/* Default values for Fast Charge Current & Float Voltage */
+#define CHG_CC_DEFAULT_UA			2266770
+#define CHG_FV_DEFAULT_MV			4300
+
+struct max77759_charger {
+	struct device *dev;
+	struct regmap *regmap;
+	struct power_supply *psy;
+	int irq[2];
+	struct regulator_dev *usb_otg_rdev;
+	struct notifier_block nb;
+	struct power_supply *tcpm_psy;
+	struct work_struct psy_work;
+	struct mutex lock; /* protects the state below */
+	enum chg_mode mode;
+};
+
+static inline int regval_to_val(int reg, int reg_offset, int step, int minval)
+{
+	return ((reg - reg_offset) * step) + minval;
+}
+
+static inline int val_to_regval(int val, int minval, int step, int reg_offset)
+{
+	s64 dividend;
+
+	if (unlikely(step == 0))
+		return reg_offset;
+
+	dividend = (s64)val - minval;
+	return DIV_S64_ROUND_CLOSEST(dividend, step) + reg_offset;
+}
+
+static inline int unlock_prot_regs(struct max77759_charger *chg, bool unlock)
+{
+	return regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_06,
+				  CHG_CNFG_06_CHGPROT,
+				  unlock ? CHG_CNFG_06_CHGPROT : 0);
+}
+
+static int charger_input_valid(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_INT_OK, &val);
+	if (ret)
+		return ret;
+
+	return (val & CHG_INT_OK_CHG_OK) && (val & CHG_INT_OK_CHGIN_OK);
+}
+
+static int get_online(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = charger_input_valid(chg);
+	if (ret <= 0)
+		return ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_DETAILS_02, &val);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&chg->lock);
+	return (val & CHG_DETAILS_02_CHGIN_STS) &&
+		(chg->mode == CHG_MODE_CHG_BUCK_ON);
+}
+
+static int get_status(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_DETAILS_01,
+			  &val);
+	if (ret)
+		return ret;
+
+	switch (FIELD_GET(CHG_DETAILS_01_CHG_DTLS, val)) {
+	case CHG_DTLS_PREQUAL:
+	case CHG_DTLS_CC:
+	case CHG_DTLS_CV:
+	case CHG_DTLS_TO:
+		return POWER_SUPPLY_STATUS_CHARGING;
+	case CHG_DTLS_DONE:
+		return POWER_SUPPLY_STATUS_FULL;
+	case CHG_DTLS_TIMER_FAULT:
+	case CHG_DTLS_SUSP_BATT_THM:
+	case CHG_DTLS_OFF_WDOG_TIMER:
+	case CHG_DTLS_SUSP_JEITA:
+		return POWER_SUPPLY_STATUS_NOT_CHARGING;
+	case CHG_DTLS_OFF:
+		return POWER_SUPPLY_STATUS_DISCHARGING;
+	default:
+		break;
+	}
+
+	return POWER_SUPPLY_STATUS_UNKNOWN;
+}
+
+static int get_charge_type(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_DETAILS_01,
+			  &val);
+	if (ret)
+		return ret;
+
+	switch (FIELD_GET(CHG_DETAILS_01_CHG_DTLS, val)) {
+	case CHG_DTLS_PREQUAL:
+		return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+	case CHG_DTLS_CC:
+		return POWER_SUPPLY_CHARGE_TYPE_FAST;
+	case CHG_DTLS_CV:
+	case CHG_DTLS_TO:
+		return POWER_SUPPLY_CHARGE_TYPE_STANDARD;
+	case CHG_DTLS_DONE:
+	case CHG_DTLS_TIMER_FAULT:
+	case CHG_DTLS_SUSP_BATT_THM:
+	case CHG_DTLS_OFF_WDOG_TIMER:
+	case CHG_DTLS_SUSP_JEITA:
+	case CHG_DTLS_OFF:
+		return POWER_SUPPLY_CHARGE_TYPE_NONE;
+	default:
+		break;
+	}
+
+	return POWER_SUPPLY_CHARGE_TYPE_UNKNOWN;
+}
+
+static int get_chg_health(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_DETAILS_00,
+			  &val);
+	if (ret)
+		return ret;
+
+	switch (FIELD_GET(CHG_DETAILS_OO_CHGIN_DTLS, val)) {
+	case CHGIN_DTLS_VBUS_UNDERVOLTAGE:
+	case CHGIN_DTLS_VBUS_MARGINAL_VOLTAGE:
+		return POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
+	case CHGIN_DTLS_VBUS_OVERVOLTAGE:
+		return POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+	case CHGIN_DTLS_VBUS_VALID:
+		return POWER_SUPPLY_HEALTH_GOOD;
+	default:
+		break;
+	}
+
+	return POWER_SUPPLY_HEALTH_UNKNOWN;
+}
+
+static int get_batt_health(struct max77759_charger *chg)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_DETAILS_01,
+			  &val);
+	if (ret)
+		return ret;
+
+	switch (FIELD_GET(CHG_DETAILS_01_BAT_DTLS, val)) {
+	case BAT_DTLS_NO_BATT_CHG_SUSP:
+		return POWER_SUPPLY_HEALTH_NO_BATTERY;
+	case BAT_DTLS_DEAD_BATTERY:
+		return POWER_SUPPLY_HEALTH_DEAD;
+	case BAT_DTLS_BAT_CHG_TIMER_FAULT:
+		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+	case BAT_DTLS_BAT_OKAY:
+	case BAT_DTLS_BAT_ONLY_MODE:
+		return POWER_SUPPLY_HEALTH_GOOD;
+	case BAT_DTLS_BAT_UNDERVOLTAGE:
+		return POWER_SUPPLY_HEALTH_UNDERVOLTAGE;
+	case BAT_DTLS_BAT_OVERVOLTAGE:
+		return POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+	case BAT_DTLS_BAT_OVERCURRENT:
+		return POWER_SUPPLY_HEALTH_OVERCURRENT;
+	default:
+		break;
+	}
+
+	return POWER_SUPPLY_HEALTH_UNKNOWN;
+}
+
+static int get_health(struct max77759_charger *chg)
+{
+	int ret;
+
+	ret = get_online(chg);
+	if (ret < 0)
+		return ret;
+
+	if (ret) {
+		ret = get_chg_health(chg);
+		if (ret < 0 || ret != POWER_SUPPLY_HEALTH_GOOD)
+			return ret;
+	}
+
+	return get_batt_health(chg);
+}
+
+static int get_fast_charge_current(struct max77759_charger *chg)
+{
+	u32 regval;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_02, &regval);
+	if (ret)
+		return ret;
+
+	ret = FIELD_GET(CHG_CNFG_02_CHGCC, regval);
+	if (ret <= CHGCC_LIMIT_REG_OFFSET)
+		return CHGCC_LIMIT_MIN_UA;
+
+	return regval_to_val(ret, CHGCC_LIMIT_REG_OFFSET, CHGCC_LIMIT_STEP_UA,
+			     CHGCC_LIMIT_MIN_UA);
+}
+
+static int set_fast_charge_current_limit(struct max77759_charger *chg, u32 cc_max_ua)
+{
+	u32 val;
+
+	if (cc_max_ua < CHGCC_LIMIT_MIN_UA || cc_max_ua > CHGCC_LIMIT_MAX_UA)
+		return -EINVAL;
+
+	val = val_to_regval(cc_max_ua, CHGCC_LIMIT_MIN_UA, CHGCC_LIMIT_STEP_UA,
+			    CHGCC_LIMIT_REG_OFFSET);
+	return regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_02,
+				  CHG_CNFG_02_CHGCC, val);
+}
+
+static int get_float_voltage(struct max77759_charger *chg)
+{
+	u32 regval;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_04, &regval);
+	if (ret)
+		return ret;
+
+	ret = FIELD_GET(CHG_CNFG_04_CHG_CV_PRM, regval);
+	switch (ret) {
+	case CHG_CV_PRM_LIMIT_HI_MIN_REG ... CHG_CV_PRM_LIMIT_HI_MAX_REG:
+		return regval_to_val(ret, CHG_CV_PRM_LIMIT_HI_MIN_REG,
+				     CHG_CV_PRM_LIMIT_HI_STEP_MV,
+				     CHG_CV_PRM_LIMIT_HI_MIN_MV);
+	case CHG_CV_PRM_LIMIT_LO_MIN_REG ... CHG_CV_PRM_LIMIT_LO_MAX_REG:
+		return regval_to_val(ret, CHG_CV_PRM_LIMIT_LO_MIN_REG,
+				     CHG_CV_PRM_LIMIT_LO_STEP_MV,
+				     CHG_CV_PRM_LIMIT_LO_MIN_MV);
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int set_float_voltage_limit(struct max77759_charger *chg, u32 fv_mv)
+{
+	u32 regval;
+
+	if (fv_mv >= CHG_CV_PRM_LIMIT_LO_MIN_MV &&
+	    fv_mv <= CHG_CV_PRM_LIMIT_LO_MAX_MV) {
+		regval = val_to_regval(fv_mv, CHG_CV_PRM_LIMIT_LO_MIN_MV,
+				       CHG_CV_PRM_LIMIT_LO_STEP_MV,
+				       CHG_CV_PRM_LIMIT_LO_MIN_REG);
+	} else if (fv_mv >= CHG_CV_PRM_LIMIT_HI_MIN_MV &&
+		   fv_mv <= CHG_CV_PRM_LIMIT_HI_MAX_MV) {
+		regval = val_to_regval(fv_mv, CHG_CV_PRM_LIMIT_HI_MIN_MV,
+				       CHG_CV_PRM_LIMIT_HI_STEP_MV,
+				       CHG_CV_PRM_LIMIT_HI_MIN_REG);
+	} else {
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_04,
+				  CHG_CNFG_04_CHG_CV_PRM, regval);
+}
+
+static int get_input_current_limit(struct max77759_charger *chg)
+{
+	u32 regval;
+	int ret;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_09, &regval);
+	if (ret)
+		return ret;
+
+	ret = FIELD_GET(CHG_CNFG_09_CHGIN_ILIM, regval);
+	if (ret <= CHGIN_ILIM_REG_OFFSET)
+		return CHGIN_ILIM_MIN_UA;
+
+	return regval_to_val(ret, CHGIN_ILIM_REG_OFFSET, CHGIN_ILIM_STEP_UA,
+			     CHGIN_ILIM_MIN_UA);
+}
+
+static int set_input_current_limit(struct max77759_charger *chg, int ilim_ua)
+{
+	u32 regval;
+
+	if (ilim_ua < 0)
+		return -EINVAL;
+
+	if (ilim_ua == 0)
+		ilim_ua = CHGIN_ILIM_MIN_UA;
+	else if (ilim_ua > CHGIN_ILIM_MAX_UA)
+		ilim_ua = CHGIN_ILIM_MAX_UA;
+
+	regval = val_to_regval(ilim_ua, CHGIN_ILIM_MIN_UA,
+			       CHGIN_ILIM_STEP_UA, CHGIN_ILIM_REG_OFFSET);
+	return regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_09,
+				  CHG_CNFG_09_CHGIN_ILIM, regval);
+}
+
+static const enum power_supply_property max77759_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_CONSTANT_CHARGE_CURRENT_MAX,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+};
+
+static int max77759_charger_get_property(struct power_supply *psy,
+					 enum power_supply_property psp,
+					 union power_supply_propval *pval)
+{
+	struct max77759_charger *chg = power_supply_get_drvdata(psy);
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		ret = get_online(chg);
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		ret = charger_input_valid(chg);
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = get_status(chg);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		ret = get_charge_type(chg);
+		break;
+	case POWER_SUPPLY_PROP_HEALTH:
+		ret = get_health(chg);
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		ret = get_fast_charge_current(chg);
+		break;
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		ret = get_float_voltage(chg);
+		break;
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		ret = get_input_current_limit(chg);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	pval->intval = ret;
+	return ret < 0 ? ret : 0;
+}
+
+static const struct power_supply_desc max77759_charger_desc = {
+	.name = "max77759-charger",
+	.type = POWER_SUPPLY_TYPE_USB,
+	.properties = max77759_charger_props,
+	.num_properties = ARRAY_SIZE(max77759_charger_props),
+	.get_property = max77759_charger_get_property,
+};
+
+static int charger_set_mode(struct max77759_charger *chg, enum chg_mode mode)
+{
+	int ret;
+
+	guard(mutex)(&chg->lock);
+
+	if (chg->mode == mode)
+		return 0;
+
+	if ((mode == CHG_MODE_CHG_BUCK_ON || mode == CHG_MODE_OTG_BOOST_ON) &&
+	    chg->mode != CHG_MODE_OFF) {
+		dev_err(chg->dev, "Invalid mode transition from %d to %d",
+			chg->mode, mode);
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_00,
+				 CHG_CNFG_00_MODE, mode);
+	if (ret)
+		return ret;
+
+	chg->mode = mode;
+	return 0;
+}
+
+static int enable_usb_otg(struct regulator_dev *rdev)
+{
+	struct max77759_charger *chg = rdev_get_drvdata(rdev);
+
+	return charger_set_mode(chg, CHG_MODE_OTG_BOOST_ON);
+}
+
+static int disable_usb_otg(struct regulator_dev *rdev)
+{
+	struct max77759_charger *chg = rdev_get_drvdata(rdev);
+
+	return charger_set_mode(chg, CHG_MODE_OFF);
+}
+
+static int usb_otg_status(struct regulator_dev *rdev)
+{
+	struct max77759_charger *chg = rdev_get_drvdata(rdev);
+
+	guard(mutex)(&chg->lock);
+	return chg->mode == CHG_MODE_OTG_BOOST_ON;
+}
+
+static const struct regulator_ops usb_otg_reg_ops = {
+	.enable = enable_usb_otg,
+	.disable = disable_usb_otg,
+	.is_enabled = usb_otg_status,
+};
+
+static const struct regulator_desc usb_otg_reg_desc = {
+	.name = "usb-otg-vbus",
+	.of_match = of_match_ptr("usb-otg-vbus-regulator"),
+	.owner = THIS_MODULE,
+	.ops = &usb_otg_reg_ops,
+	.fixed_uV = 5000000,
+	.n_voltages = 1,
+};
+
+static irqreturn_t irq_handler(int irq, void *data)
+{
+	struct max77759_charger *chg = data;
+	u32 irq_status, chgint_ok, idx = 0;
+	int ret;
+
+	if (irq == chg->irq[0])
+		idx = 0;
+	else
+		idx = 1;
+
+	ret = regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_INT + idx,
+			  &irq_status);
+	if (ret) {
+		dev_err(chg->dev, "regmap_read_error idx=%d ret=%d", idx, ret);
+		return IRQ_HANDLED;
+	}
+
+	regmap_write(chg->regmap, MAX77759_CHGR_REG_CHG_INT + idx,
+		     irq_status);
+	regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_INT_OK, &chgint_ok);
+
+	if (idx == 0) {
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT_AICL)
+			dev_dbg(chg->dev, "AICL mode: %s",
+				str_no_yes(chgint_ok & CHG_INT_OK_AICL_OK));
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT_CHGIN)
+			dev_dbg(chg->dev, "CHGIN input valid: %s",
+				str_yes_no(chgint_ok & CHG_INT_OK_CHGIN_OK));
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT_CHG)
+			dev_dbg(chg->dev, "CHG status okay/off: %s",
+				str_yes_no(chgint_ok & CHG_INT_OK_CHG_OK));
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT_INLIM)
+			dev_dbg(chg->dev, "Current Limit reached: %s",
+				str_no_yes(chgint_ok & CHG_INT_OK_INLIM_OK));
+	} else {
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT2_BAT_OILO)
+			dev_dbg(chg->dev,
+				"Battery over-current threshold crossed");
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT2_CHG_STA_CC)
+			dev_dbg(chg->dev, "Charger reached CC stage");
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT2_CHG_STA_CV)
+			dev_dbg(chg->dev, "Charger reached CV stage");
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT2_CHG_STA_TO)
+			dev_dbg(chg->dev, "Charger reached TO stage");
+
+		if (irq_status & MAX77759_CHGR_REG_CHG_INT2_CHG_STA_DONE)
+			dev_dbg(chg->dev, "Charger reached Done stage");
+	}
+
+	power_supply_changed(chg->psy);
+	return IRQ_HANDLED;
+}
+
+static int max77759_init_irqhandler(struct max77759_charger *chg)
+{
+	static const char * const irq_res_names[] = { "INT1", "INT2" };
+	struct device *dev = chg->dev;
+	unsigned long irq_flags;
+	struct irq_data *irqd;
+	int *irq = chg->irq;
+	int ret, i;
+
+	for (i = 0; i < 2; i++) {
+		irq[i] = platform_get_irq_byname(to_platform_device(dev),
+						 irq_res_names[i]);
+		if (irq[i] < 0) {
+			dev_err(dev, "unable to find %s irq", irq_res_names[i]);
+			return irq[i];
+		}
+
+		irq_flags = IRQF_ONESHOT | IRQF_SHARED;
+		irqd = irq_get_irq_data(irq[i]);
+		if (irqd)
+			irq_flags |= irqd_get_trigger_type(irqd);
+
+		ret = devm_request_threaded_irq(dev, irq[i], NULL, irq_handler,
+						irq_flags, dev_name(dev), chg);
+		if (ret) {
+			dev_err(dev, "Unable to register threaded irq handler");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int max77759_charger_init(struct max77759_charger *chg)
+{
+	int ret;
+	u32 regval;
+
+	regmap_read(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_00, &regval);
+	chg->mode = FIELD_GET(CHG_CNFG_00_MODE, regval);
+	ret = charger_set_mode(chg, CHG_MODE_OFF);
+	if (ret)
+		return ret;
+
+	ret = set_fast_charge_current_limit(chg, CHG_CC_DEFAULT_UA);
+	if (ret)
+		return ret;
+
+	ret = set_float_voltage_limit(chg, CHG_FV_DEFAULT_MV);
+	if (ret)
+		return ret;
+
+	ret = unlock_prot_regs(chg, true);
+	if (ret)
+		return ret;
+
+	/* Disable wireless charging input */
+	regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_12,
+			   CHG_CNFG_12_WCINSEL, 0);
+
+	regmap_update_bits(chg->regmap, MAX77759_CHGR_REG_CHG_CNFG_18,
+			   CHG_CNFG_18_WDTEN, 0);
+
+	return unlock_prot_regs(chg, false);
+}
+
+static void psy_work_item(struct work_struct *work)
+{
+	struct max77759_charger *chg =
+		container_of(work, struct max77759_charger, psy_work);
+	union power_supply_propval current_limit = { 0 }, online = { 0 };
+	int ret;
+
+	power_supply_get_property(chg->tcpm_psy, POWER_SUPPLY_PROP_CURRENT_MAX,
+				  &current_limit);
+	power_supply_get_property(chg->tcpm_psy, POWER_SUPPLY_PROP_ONLINE,
+				  &online);
+
+	if (online.intval && current_limit.intval) {
+		ret = set_input_current_limit(chg, current_limit.intval);
+		if (ret)
+			dev_err(chg->dev,
+				"Unable to set current limit, ret=%d", ret);
+
+		charger_set_mode(chg, CHG_MODE_CHG_BUCK_ON);
+	} else {
+		charger_set_mode(chg, CHG_MODE_OFF);
+	}
+}
+
+static int psy_changed(struct notifier_block *nb, unsigned long evt, void *data)
+{
+	struct max77759_charger *chg = container_of(nb, struct max77759_charger,
+						    nb);
+	const char *psy_name = "tcpm-source";
+	struct power_supply *psy = data;
+
+	if (!strnstr(psy->desc->name, psy_name, strlen(psy_name)) ||
+	    evt != PSY_EVENT_PROP_CHANGED)
+		return NOTIFY_OK;
+
+	chg->tcpm_psy = psy;
+	schedule_work(&chg->psy_work);
+	return NOTIFY_OK;
+}
+
+static void max_tcpci_unregister_psy_notifier(void *nb)
+{
+	power_supply_unreg_notifier(nb);
+}
+
+static int max77759_charger_probe(struct platform_device *pdev)
+{
+	struct regulator_config usb_otg_reg_cfg;
+	struct power_supply_config psy_cfg;
+	struct device *dev = &pdev->dev;
+	struct max77759_charger *chg;
+	int ret;
+
+	chg = devm_kzalloc(dev, sizeof(*chg), GFP_KERNEL);
+	if (!chg)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, chg);
+	chg->dev = dev;
+	chg->regmap = dev_get_regmap(dev->parent, "charger");
+	if (!chg->regmap)
+		return dev_err_probe(dev, -ENODEV, "Missing regmap");
+
+	ret = devm_mutex_init(dev, &chg->lock);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to initialize lock");
+
+	ret = max77759_charger_init(chg);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to initialize max77759 charger");
+
+	usb_otg_reg_cfg.dev = dev;
+	usb_otg_reg_cfg.driver_data = chg;
+	usb_otg_reg_cfg.of_node = dev_of_node(dev);
+	chg->usb_otg_rdev = devm_regulator_register(dev, &usb_otg_reg_desc,
+						    &usb_otg_reg_cfg);
+	if (IS_ERR(chg->usb_otg_rdev))
+		return dev_err_probe(dev, PTR_ERR(chg->usb_otg_rdev),
+				     "Failed to register usb otg regulator");
+
+	psy_cfg.fwnode = dev_fwnode(dev);
+	psy_cfg.drv_data = chg;
+	chg->psy = devm_power_supply_register(dev, &max77759_charger_desc,
+					      &psy_cfg);
+	if (IS_ERR(chg->psy))
+		return dev_err_probe(dev, -EPROBE_DEFER,
+				     "Failed to register psy, ret=%ld",
+				     PTR_ERR(chg->psy));
+
+	ret = devm_work_autocancel(dev, &chg->psy_work, psy_work_item);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to initialize psy work");
+
+	chg->nb.notifier_call = psy_changed;
+	ret = power_supply_reg_notifier(&chg->nb);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Unable to register psy notifier");
+
+	ret = devm_add_action_or_reset(dev, max_tcpci_unregister_psy_notifier,
+				       &chg->nb);
+	if (ret)
+		return ret;
+
+	ret = max77759_init_irqhandler(chg);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Unable to initialize irq handler");
+	return 0;
+}
+
+static const struct of_device_id max77759_charger_ids[] = {
+	{ .compatible = "maxim,max77759-charger", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, max77759_charger_ids);
+
+static struct platform_driver max77759_charger_driver = {
+	.driver = {
+		.name = "max77759-charger",
+		.of_match_table = max77759_charger_ids,
+	},
+	.probe = max77759_charger_probe,
+};
+module_platform_driver(max77759_charger_driver);
+
+MODULE_AUTHOR("Amit Sunil Dhamne <amitsd@...gle.com>");
+MODULE_DESCRIPTION("Maxim MAX77759 charger driver");
+MODULE_LICENSE("GPL");

-- 
2.52.0.rc2.455.g230fcf2819-goog

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