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* [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
@ 2015-04-29 20:13 ` Anda-Maria Nicolae
  0 siblings, 0 replies; 8+ messages in thread
From: Anda-Maria Nicolae @ 2015-04-29 20:13 UTC (permalink / raw)
  To: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

Based on the datasheet found here:
http://www.richtek.com/download_ds.jsp?p=RT9455

Updates from the previous version:
- replaced license GPLv2 with GPL
- replaced vendor prefix rt with richtek
- replaced uppercase properties names from devicetree with lowercase separated by dash properties names
- replaced I/O read/write API with regmap_read/write and regmap_field_read/write
- used kernel multiline comment
- used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.
- replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc 
- replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
- replaced {"RTK9455", 0} with { "RTK9455", 0 }
- removed .owner = THIS_MODULE

Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
---
 .../devicetree/bindings/power/rt9455_charger.txt   |   43 +
 .../devicetree/bindings/vendor-prefixes.txt        |    1 +
 drivers/power/Kconfig                              |    6 +
 drivers/power/Makefile                             |    1 +
 drivers/power/rt9455_charger.c                     | 1758 ++++++++++++++++++++
 5 files changed, 1809 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/rt9455_charger.txt
 create mode 100644 drivers/power/rt9455_charger.c

diff --git a/Documentation/devicetree/bindings/power/rt9455_charger.txt b/Documentation/devicetree/bindings/power/rt9455_charger.txt
new file mode 100644
index 0000000..7e8aed6
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/rt9455_charger.txt
@@ -0,0 +1,43 @@
+Binding for Richtek rt9455 battery charger
+
+Required properties:
+- compatible: Should contain one of the following:
+ * "richtek,rt9455"
+
+- reg:					integer, i2c address of the device.
+- richtek,output-charge-current:	integer, output current from the charger to the
+					battery, in uA.
+- richtek,end-of-charge-percentage:	integer, percent of the output charge current.
+					When the current in constant-voltage phase drops
+					below output_charge_current x end-of-charge-percentage,
+					charge is terminated.
+- richtek,battery-regulation-voltage:	integer, maximum battery voltage in uV.
+
+Optional properties:
+- richtek,min-input-voltage-regulation: integer, input voltage level in uA, used to
+					decrease voltage level when the over current
+					of the input power source occurs.
+					This prevents input voltage drop due to insufficient
+					current provided by the power source.
+- richtek,avg-input-current-regulation: integer, input current value drained by the
+					charger from the power source.
+
+Example:
+
+rt9455@22 {
+	compatible = "richtek,rt9455";
+	reg = <0x22>;
+
+	interrupt-parent = <&gpio1>;
+	interrupts = <0 1>;
+
+	interrupt-gpio = <&gpio1 0 1>;
+	reset-gpio = <&gpio1 1 1>;
+
+	richtek,output-charge-current	    = <500000>;
+	richtek,end-of-charge-percentage    = <10>;
+	richtek,battery-regulation-voltage  = <4200000>;
+
+	richtek,min-input-voltage-regulation = <4500000>;
+	richtek,avg-input-current-regulation = <500000>;
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 389ca13..92a9508 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -148,6 +148,7 @@ raidsonic	RaidSonic Technology GmbH
 ralink	Mediatek/Ralink Technology Corp.
 ramtron	Ramtron International
 realtek Realtek Semiconductor Corp.
+richtek	Richtek Technology Corporation
 renesas	Renesas Electronics Corporation
 ricoh	Ricoh Co. Ltd.
 rockchip	Fuzhou Rockchip Electronics Co., Ltd
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 4091fb0..39f208d 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -439,6 +439,12 @@ config BATTERY_RT5033
 	  The fuelgauge calculates and determines the battery state of charge
 	  according to battery open circuit voltage.
 
+config CHARGER_RT9455
+	tristate "Richtek RT9455 battery charger driver"
+	depends on I2C && GPIOLIB
+	help
+	Say Y to enable support for the Richtek RT9455 battery charger.
+
 source "drivers/power/reset/Kconfig"
 
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b7b0181..e49abbf 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_MAX17042)	+= max17042_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
 obj-$(CONFIG_BATTERY_RT5033)	+= rt5033_battery.o
+obj-$(CONFIG_CHARGER_RT9455)	+= rt9455_charger.o
 obj-$(CONFIG_BATTERY_S3C_ADC)	+= s3c_adc_battery.o
 obj-$(CONFIG_BATTERY_TWL4030_MADC)	+= twl4030_madc_battery.o
 obj-$(CONFIG_CHARGER_88PM860X)	+= 88pm860x_charger.o
diff --git a/drivers/power/rt9455_charger.c b/drivers/power/rt9455_charger.c
new file mode 100644
index 0000000..e45b0f2
--- /dev/null
+++ b/drivers/power/rt9455_charger.c
@@ -0,0 +1,1758 @@
+/*
+ * Driver for Richtek RT9455WSC battery charger.
+ *
+ * Copyright (C) 2015 Intel Corporation
+ *
+ * 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/interrupt.h>
+#include <linux/delay.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/usb/phy.h>
+#include <linux/regmap.h>
+
+#define RT9455_MANUFACTURER			"Richtek"
+#define RT9455_MODEL_NAME			"RT9455"
+#define RT9455_DRIVER_NAME			"rt9455-charger"
+
+#define RT9455_IRQ_NAME				"interrupt"
+
+#define RT9455_PWR_RDY_DELAY			1 /* 1 second */
+#define RT9455_MAX_CHARGING_TIME		21600 /* 6 hrs */
+#define RT9455_BATT_PRESENCE_DELAY		60 /* 60 seconds */
+
+#define RT9455_CHARGE_MODE			0x00
+#define RT9455_BOOST_MODE			0x01
+
+#define RT9455_FAULT				0x03
+
+#define RT9455_IAICR_100MA			0x00
+#define RT9455_IAICR_500MA			0x01
+#define RT9455_IAICR_NO_LIMIT			0x03
+
+#define RT9455_CHARGE_DISABLE			0x00
+#define RT9455_CHARGE_ENABLE			0x01
+
+#define RT9455_PWR_FAULT			0x00
+#define RT9455_PWR_GOOD				0x01
+
+#define RT9455_REG_CTRL1			0x00 /* CTRL1 reg address */
+#define RT9455_REG_CTRL1_STAT_MASK		(BIT(5) | BIT(4))
+#define RT9455_REG_CTRL1_BOOST_MASK		BIT(3)
+#define RT9455_REG_CTRL1_PWR_RDY_MASK		BIT(2)
+#define RT9455_REG_CTRL1_OTG_PIN_POLARITY_MASK	BIT(1)
+
+#define RT9455_REG_CTRL2			0x01 /* CTRL2 reg address */
+#define RT9455_REG_CTRL2_IAICR_MASK		(BIT(7) | BIT(6))
+#define RT9455_REG_CTRL2_TE_SHDN_EN_MASK	BIT(5)
+#define RT9455_REG_CTRL2_HIGHER_OCP_MASK	BIT(4)
+#define RT9455_REG_CTRL2_TE_MASK		BIT(3)
+#define RT9455_REG_CTRL2_IAICR_INT_MASK		BIT(2)
+#define RT9455_REG_CTRL2_HIZ_MASK		BIT(1)
+#define RT9455_REG_CTRL2_OPA_MODE_MASK		BIT(0)
+
+#define RT9455_REG_CTRL3			0x02 /* CTRL3 reg address */
+#define RT9455_REG_CTRL3_VOREG_MASK		(BIT(7) | BIT(6) | BIT(5) | \
+						 BIT(4) | BIT(3) | BIT(2))
+#define RT9455_REG_CTRL3_OTG_PL_MASK		BIT(1)
+#define RT9455_REG_CTRL3_OTG_EN_MASK		BIT(0)
+
+#define RT9455_REG_DEV_ID			0x03 /* DEV_ID reg address */
+#define RT9455_REG_DEV_ID_VENDOR_ID_MASK	(BIT(7) | BIT(6) | BIT(5) | \
+						 BIT(4))
+#define RT9455_REG_DEV_ID_CHIP_REV_MASK		(BIT(3) | BIT(2) | BIT(1) | \
+						 BIT(0))
+
+#define RT9455_REG_CTRL4			0x04 /* CTRL4 reg address */
+#define RT9455_REG_CTRL4_RST_MASK		BIT(7)
+
+#define RT9455_REG_CTRL5			0x05 /* CTRL5 reg address */
+#define RT9455_REG_CTRL5_TMR_EN_MASK		BIT(7)
+#define RT9455_REG_CTRL5_MIVR_MASK		(BIT(5) | BIT(4))
+#define RT9455_REG_CTRL5_IPREC_MASK		(BIT(3) | BIT(2))
+#define RT9455_REG_CTRL5_IEOC_PERCENTAGE_MASK	(BIT(1) | BIT(0))
+
+#define RT9455_REG_CTRL6			0x06 /* CTRL6 reg address */
+#define RT9455_REG_CTRL6_IAICR_SEL_MASK		BIT(7)
+#define RT9455_REG_CTRL6_ICHRG_MASK		(BIT(6) | BIT(5) | BIT(4))
+#define RT9455_REG_CTRL6_VPREC_MASK		(BIT(2) | BIT(1) | BIT(0))
+
+#define RT9455_REG_CTRL7			0x07 /* CTRL7 reg address */
+#define RT9455_REG_CTRL7_BATD_EN_MASK		BIT(6)
+#define RT9455_REG_CTRL7_CHG_EN_MASK		BIT(4)
+#define RT9455_REG_CTRL7_VMREG_MASK		(BIT(3) | BIT(2) | BIT(1) | \
+						 BIT(0))
+
+#define RT9455_REG_IRQ1				0x08 /* IRQ1 reg address */
+#define RT9455_REG_IRQ1_TSDI_MASK		BIT(7)
+#define RT9455_REG_IRQ1_VINOVPI_MASK		BIT(6)
+#define RT9455_REG_IRQ1_BATAB_MASK		BIT(0)
+
+#define RT9455_REG_IRQ2				0x09 /* IRQ2 reg address */
+#define RT9455_REG_IRQ2_CHRVPI_MASK		BIT(7)
+#define RT9455_REG_IRQ2_CHBATOVI_MASK		BIT(5)
+#define RT9455_REG_IRQ2_CHTERMI_MASK		BIT(4)
+#define RT9455_REG_IRQ2_CHRCHGI_MASK		BIT(3)
+#define RT9455_REG_IRQ2_CH32MI_MASK		BIT(2)
+#define RT9455_REG_IRQ2_CHTREGI_MASK		BIT(1)
+#define RT9455_REG_IRQ2_CHMIVRI_MASK		BIT(0)
+
+#define RT9455_REG_IRQ3				0x0A /* IRQ3 reg address */
+#define RT9455_REG_IRQ3_BSTBUSOVI_MASK		BIT(7)
+#define RT9455_REG_IRQ3_BSTOLI_MASK		BIT(6)
+#define RT9455_REG_IRQ3_BSTLOWVI_MASK		BIT(5)
+#define RT9455_REG_IRQ3_BST32SI_MASK		BIT(3)
+
+#define RT9455_REG_MASK1			0x0B /* MASK1 reg address */
+#define RT9455_REG_MASK1_TSDM_MASK		BIT(7)
+#define RT9455_REG_MASK1_VINOVPIM_MASK		BIT(6)
+#define RT9455_REG_MASK1_BATABM_MASK		BIT(0)
+
+#define RT9455_REG_MASK2			0x0C /* MASK2 reg address */
+#define RT9455_REG_MASK2_CHRVPIM_MASK		BIT(7)
+#define RT9455_REG_MASK2_CHBATOVIM_MASK		BIT(5)
+#define RT9455_REG_MASK2_CHTERMIM_MASK		BIT(4)
+#define RT9455_REG_MASK2_CHRCHGIM_MASK		BIT(3)
+#define RT9455_REG_MASK2_CH32MIM_MASK		BIT(2)
+#define RT9455_REG_MASK2_CHTREGIM_MASK		BIT(1)
+#define RT9455_REG_MASK2_CHMIVRIM_MASK		BIT(0)
+
+#define RT9455_REG_MASK3			0x0D /* MASK3 reg address */
+#define RT9455_REG_MASK3_BSTVINOVIM_MASK	BIT(7)
+#define RT9455_REG_MASK3_BSTOLIM_MASK		BIT(6)
+#define RT9455_REG_MASK3_BSTLOWVIM_MASK		BIT(5)
+#define RT9455_REG_MASK3_BST32SIM_MASK		BIT(3)
+
+enum rt9455_fields {
+	F_STAT, F_BOOST, F_PWR_RDY, F_OTG_PIN_POLARITY, /* CTRL1 reg fields */
+
+	F_IAICR, F_TE_SHDN_EN, F_HIGHER_OCP, F_TE, F_IAICR_INT, F_HIZ,
+	F_OPA_MODE, /* CTRL2 reg fields */
+
+	F_VOREG, F_OTG_PL, F_OTG_EN, /* CTRL3 reg fields */
+
+	F_VENDOR_ID, F_CHIP_REV, /* DEV_ID reg fields */
+
+	F_RST, /* CTRL4 reg fields */
+
+	F_TMR_EN, F_MIVR, F_IPREC, F_IEOC_PERCENTAGE, /* CTRL5 reg fields*/
+
+	F_IAICR_SEL, F_ICHRG, F_VPREC, /* CTRL6 reg fields */
+
+	F_BATD_EN, F_CHG_EN, F_VMREG, /* CTRL7 reg fields */
+
+	F_TSDI, F_VINOVPI, F_BATAB, /* IRQ1 reg fields */
+
+	F_CHRVPI, F_CHBATOVI, F_CHTERMI, F_CHRCHGI, F_CH32MI, F_CHTREGI,
+	F_CHMIVRI, /* IRQ2 reg fields */
+
+	F_BSTBUSOVI, F_BSTOLI, F_BSTLOWVI, F_BST32SI, /* IRQ3 reg fields */
+
+	F_TSDM, F_VINOVPIM, F_BATABM, /* MASK1 reg fields */
+
+	F_CHRVPIM, F_CHBATOVIM, F_CHTERMIM, F_CHRCHGIM, F_CH32MIM, F_CHTREGIM,
+	F_CHMIVRIM, /* MASK2 reg fields */
+
+	F_BSTVINOVIM, F_BSTOLIM, F_BSTLOWVIM, F_BST32SIM, /* MASK3 reg fields */
+
+	F_MAX_FIELDS
+};
+
+static const struct reg_field rt9455_reg_fields[] = {
+	[F_STAT]		= REG_FIELD(RT9455_REG_CTRL1, 4, 5),
+	[F_BOOST]		= REG_FIELD(RT9455_REG_CTRL1, 3, 3),
+	[F_PWR_RDY]		= REG_FIELD(RT9455_REG_CTRL1, 2, 2),
+	[F_OTG_PIN_POLARITY]	= REG_FIELD(RT9455_REG_CTRL1, 1, 1),
+
+	[F_IAICR]		= REG_FIELD(RT9455_REG_CTRL2, 6, 7),
+	[F_TE_SHDN_EN]		= REG_FIELD(RT9455_REG_CTRL2, 5, 5),
+	[F_HIGHER_OCP]		= REG_FIELD(RT9455_REG_CTRL2, 4, 4),
+	[F_TE]			= REG_FIELD(RT9455_REG_CTRL2, 3, 3),
+	[F_IAICR_INT]		= REG_FIELD(RT9455_REG_CTRL2, 2, 2),
+	[F_HIZ]			= REG_FIELD(RT9455_REG_CTRL2, 1, 1),
+	[F_OPA_MODE]		= REG_FIELD(RT9455_REG_CTRL2, 0, 0),
+
+	[F_VOREG]		= REG_FIELD(RT9455_REG_CTRL3, 2, 7),
+	[F_OTG_PL]		= REG_FIELD(RT9455_REG_CTRL3, 1, 1),
+	[F_OTG_EN]		= REG_FIELD(RT9455_REG_CTRL3, 0, 0),
+
+	[F_VENDOR_ID]		= REG_FIELD(RT9455_REG_DEV_ID, 4, 7),
+	[F_CHIP_REV]		= REG_FIELD(RT9455_REG_DEV_ID, 0, 3),
+
+	[F_RST]			= REG_FIELD(RT9455_REG_CTRL4, 7, 7),
+
+	[F_TMR_EN]		= REG_FIELD(RT9455_REG_CTRL5, 7, 7),
+	[F_MIVR]		= REG_FIELD(RT9455_REG_CTRL5, 4, 5),
+	[F_IPREC]		= REG_FIELD(RT9455_REG_CTRL5, 2, 3),
+	[F_IEOC_PERCENTAGE]	= REG_FIELD(RT9455_REG_CTRL5, 0, 1),
+
+	[F_IAICR_SEL]		= REG_FIELD(RT9455_REG_CTRL6, 7, 7),
+	[F_ICHRG]		= REG_FIELD(RT9455_REG_CTRL6, 4, 6),
+	[F_VPREC]		= REG_FIELD(RT9455_REG_CTRL6, 0, 2),
+
+	[F_BATD_EN]		= REG_FIELD(RT9455_REG_CTRL7, 6, 6),
+	[F_CHG_EN]		= REG_FIELD(RT9455_REG_CTRL7, 4, 4),
+	[F_VMREG]		= REG_FIELD(RT9455_REG_CTRL7, 0, 3),
+
+	[F_TSDI]		= REG_FIELD(RT9455_REG_IRQ1, 7, 7),
+	[F_VINOVPI]		= REG_FIELD(RT9455_REG_IRQ1, 6, 6),
+	[F_BATAB]		= REG_FIELD(RT9455_REG_IRQ1, 0, 0),
+
+	[F_CHRVPI]		= REG_FIELD(RT9455_REG_IRQ2, 7, 7),
+	[F_CHBATOVI]		= REG_FIELD(RT9455_REG_IRQ2, 5, 5),
+	[F_CHTERMI]		= REG_FIELD(RT9455_REG_IRQ2, 4, 4),
+	[F_CHRCHGI]		= REG_FIELD(RT9455_REG_IRQ2, 3, 3),
+	[F_CH32MI]		= REG_FIELD(RT9455_REG_IRQ2, 2, 2),
+	[F_CHTREGI]		= REG_FIELD(RT9455_REG_IRQ2, 1, 1),
+	[F_CHMIVRI]		= REG_FIELD(RT9455_REG_IRQ2, 0, 0),
+
+	[F_BSTBUSOVI]		= REG_FIELD(RT9455_REG_IRQ3, 7, 7),
+	[F_BSTOLI]		= REG_FIELD(RT9455_REG_IRQ3, 6, 6),
+	[F_BSTLOWVI]		= REG_FIELD(RT9455_REG_IRQ3, 5, 5),
+	[F_BST32SI]		= REG_FIELD(RT9455_REG_IRQ3, 3, 3),
+
+	[F_TSDM]		= REG_FIELD(RT9455_REG_MASK1, 7, 7),
+	[F_VINOVPIM]		= REG_FIELD(RT9455_REG_MASK1, 6, 6),
+	[F_BATABM]		= REG_FIELD(RT9455_REG_MASK1, 0, 0),
+
+	[F_CHRVPIM]		= REG_FIELD(RT9455_REG_MASK2, 7, 7),
+	[F_CHBATOVIM]		= REG_FIELD(RT9455_REG_MASK2, 5, 5),
+	[F_CHTERMIM]		= REG_FIELD(RT9455_REG_MASK2, 4, 4),
+	[F_CHRCHGIM]		= REG_FIELD(RT9455_REG_MASK2, 3, 3),
+	[F_CH32MIM]		= REG_FIELD(RT9455_REG_MASK2, 2, 2),
+	[F_CHTREGIM]		= REG_FIELD(RT9455_REG_MASK2, 1, 1),
+	[F_CHMIVRIM]		= REG_FIELD(RT9455_REG_MASK2, 0, 0),
+
+	[F_BSTVINOVIM]		= REG_FIELD(RT9455_REG_MASK3, 7, 7),
+	[F_BSTOLIM]		= REG_FIELD(RT9455_REG_MASK3, 6, 6),
+	[F_BSTLOWVIM]		= REG_FIELD(RT9455_REG_MASK3, 5, 5),
+	[F_BST32SIM]		= REG_FIELD(RT9455_REG_MASK3, 3, 3),
+};
+
+/*
+ * Each array initialised below shows the possible real-world values for a
+ * group of bits belonging to RT9455 registers. The arrays are sorted in
+ * ascending order. The index of each real-world value represents the value
+ * that is encoded in the group of bits belonging to RT9455 registers.
+ */
+/* REG06[6:4] (ICHRG) in uAh */
+static const int rt9455_ichrg_values[] = {
+	 500000,  650000,  800000,  950000, 1100000, 1250000, 1400000, 1550000
+};
+
+/* REG02[7:2] (VOREG) in uV */
+static const int rt9455_voreg_values[] = {
+	3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
+	3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
+	3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
+	3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
+	4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
+	4300000, 4330000, 4350000, 4370000, 4390000, 4410000, 4430000, 4450000,
+	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000,
+	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000
+};
+
+/* REG07[3:0] (VMREG) in uV */
+static const int rt9455_vmreg_values[] = {
+	4200000, 4220000, 4240000, 4260000, 4280000, 4300000, 4320000, 4340000,
+	4360000, 4380000, 4400000, 4430000, 4450000, 4450000, 4450000, 4450000
+};
+
+/* REG05[5:4] (IEOC_PERCENTAGE) */
+static const int rt9455_ieoc_percentage_values[] = {
+	10, 30, 20, 30
+};
+
+/* REG05[1:0] (MIVR) in uV */
+static const int rt9455_mivr_values[] = {
+	4000000, 4250000, 4500000, 5000000
+};
+
+/* REG05[1:0] (IAICR) in uA */
+static const int rt9455_iaicr_values[] = {
+	100000, 500000, 1000000, 2000000
+};
+
+struct rt9455_info {
+	struct i2c_client		*client;
+	struct regmap			*regmap;
+	struct regmap_field		*regmap_fields[F_MAX_FIELDS];
+	struct power_supply		*charger;
+#if IS_ENABLED(CONFIG_USB_PHY)
+	struct usb_phy			*usb_phy;
+	struct notifier_block		nb;
+#endif
+	struct gpio_desc		*gpiod_irq;
+	unsigned int			gpio_irq;
+	struct delayed_work		pwr_rdy_work;
+	struct delayed_work		max_charging_time_work;
+	struct delayed_work		batt_presence_work;
+};
+
+static const struct regmap_config rt9455_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RT9455_REG_MASK3,
+};
+
+/*
+ * Iterate through each element of the 'tbl' array until an element whose value
+ * is greater than v is found. Return the index of the respective element,
+ * or the index of the last element in the array, if no such element is found.
+ */
+static u8 rt9455_find_idx(const int tbl[], int tbl_size, int v)
+{
+	int i;
+
+	/*
+	 * No need to iterate until the last index in the table because
+	 * if no element greater than v is found in the table,
+	 * or if only the last element is greater than v,
+	 * function returns the index of the last element.
+	 */
+	for (i = 0; i < tbl_size - 1; i++)
+		if (v <= tbl[i])
+			return i;
+
+	return (tbl_size - 1);
+}
+
+static int rt9455_get_field_val(struct rt9455_info *info,
+				enum rt9455_fields field,
+				const int tbl[], int tbl_size, int *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[field], &v);
+	if (ret)
+		return ret;
+
+	v = (v >= tbl_size) ? (tbl_size - 1) : v;
+	*val = tbl[v];
+
+	return 0;
+}
+
+static int rt9455_set_field_val(struct rt9455_info *info,
+				enum rt9455_fields field,
+				const int tbl[], int tbl_size, int val)
+{
+	u8 idx = rt9455_find_idx(tbl, tbl_size, val);
+
+	return regmap_field_write(info->regmap_fields[field], idx);
+}
+
+static int rt9455_register_reset(struct rt9455_info *info)
+{
+	struct device *dev = &info->client->dev;
+	unsigned int v;
+	int ret, limit = 100;
+
+	ret = regmap_field_write(info->regmap_fields[F_RST], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to set RST bit\n");
+		return ret;
+	}
+
+	/*
+	 * To make sure that reset operation has finished, loop until RST bit
+	 * is set to 0.
+	 */
+	do {
+		ret = regmap_field_read(info->regmap_fields[F_RST], &v);
+		if (ret) {
+			dev_err(dev, "Failed to read RST bit\n");
+			return ret;
+		}
+
+		if (!v)
+			break;
+
+		usleep_range(10, 100);
+	} while (--limit);
+
+	if (!limit)
+		return -EIO;
+
+	return 0;
+}
+
+/* Charger power supply property routines */
+static enum power_supply_property rt9455_charger_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+	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_SCOPE,
+	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static char *rt9455_charger_supplied_to[] = {
+	"main-battery",
+};
+
+static int rt9455_charger_get_status(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read STAT bits\n");
+		return ret;
+	}
+
+	switch (v) {
+	case 0:
+		val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+	break;
+	case 1:
+		val->intval = POWER_SUPPLY_STATUS_CHARGING;
+	break;
+	case 2:
+		val->intval = POWER_SUPPLY_STATUS_FULL;
+	break;
+	default:
+		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+	break;
+	}
+
+	return 0;
+}
+
+static int rt9455_charger_get_health(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	struct device *dev = &info->client->dev;
+	unsigned int v;
+	int ret;
+
+	val->intval = POWER_SUPPLY_HEALTH_GOOD;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ1_TSDI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ1_VINOVPI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ1_BATAB_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ2, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ2 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ2_CHBATOVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ2_CH32MI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+		return 0;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ3, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ3 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ3_BSTBUSOVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BSTOLI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BSTLOWVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BST32SI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+		return 0;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
+	if (ret) {
+		dev_err(dev, "Failed to read STAT bits\n");
+		return ret;
+	}
+
+	if (v == RT9455_FAULT) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+
+	return 0;
+}
+
+static int rt9455_charger_get_battery_presence(struct rt9455_info *info,
+					       union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_BATAB], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read BATAB bit\n");
+		return ret;
+	}
+
+	/*
+	 * Since BATAB is 1 when battery is NOT present and 0 otherwise,
+	 * we return !BATAB.
+	 */
+	val->intval = !v;
+
+	return 0;
+}
+
+static int rt9455_charger_get_online(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_PWR_RDY], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read PWR_RDY bit\n");
+		return ret;
+	}
+
+	val->intval = (int)v;
+
+	return 0;
+}
+
+static int rt9455_charger_get_current(struct rt9455_info *info,
+				      union power_supply_propval *val)
+{
+	int curr;
+	int ret;
+
+	ret = rt9455_get_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values),
+				   &curr);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read ICHRG value\n");
+		return ret;
+	}
+
+	val->intval = curr;
+
+	return 0;
+}
+
+static int rt9455_charger_get_current_max(struct rt9455_info *info,
+					  union power_supply_propval *val)
+{
+	int idx = ARRAY_SIZE(rt9455_ichrg_values) - 1;
+
+	val->intval = rt9455_ichrg_values[idx];
+
+	return 0;
+}
+
+static int rt9455_charger_get_voltage(struct rt9455_info *info,
+				      union power_supply_propval *val)
+{
+	int voltage;
+	int ret;
+
+	ret = rt9455_get_field_val(info, F_VOREG,
+				   rt9455_voreg_values,
+				   ARRAY_SIZE(rt9455_voreg_values),
+				   &voltage);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read VOREG value\n");
+		return ret;
+	}
+
+	val->intval = voltage;
+
+	return 0;
+}
+
+static int rt9455_charger_get_voltage_max(struct rt9455_info *info,
+					  union power_supply_propval *val)
+{
+	int idx = ARRAY_SIZE(rt9455_voreg_values) - 1;
+
+	val->intval = rt9455_voreg_values[idx];
+
+	return 0;
+}
+
+static int rt9455_charger_get_term_current(struct rt9455_info *info,
+					   union power_supply_propval *val)
+{
+	struct device *dev = &info->client->dev;
+	int ichrg, ieoc_percentage, ret;
+
+	ret = rt9455_get_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values),
+				   &ichrg);
+	if (ret) {
+		dev_err(dev, "Failed to read ICHRG value\n");
+		return ret;
+	}
+
+	ret = rt9455_get_field_val(info, F_IEOC_PERCENTAGE,
+				   rt9455_ieoc_percentage_values,
+				   ARRAY_SIZE(rt9455_ieoc_percentage_values),
+				   &ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Failed to read IEOC value\n");
+		return ret;
+	}
+
+	val->intval = ichrg * ieoc_percentage / 100;
+
+	return 0;
+}
+
+static int rt9455_charger_get_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       union power_supply_propval *val)
+{
+	struct rt9455_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		return rt9455_charger_get_status(info, val);
+	case POWER_SUPPLY_PROP_HEALTH:
+		return rt9455_charger_get_health(info, val);
+	case POWER_SUPPLY_PROP_PRESENT:
+		return rt9455_charger_get_battery_presence(info, val);
+	case POWER_SUPPLY_PROP_ONLINE:
+		return rt9455_charger_get_online(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return rt9455_charger_get_current(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		return rt9455_charger_get_current_max(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return rt9455_charger_get_voltage(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return rt9455_charger_get_voltage_max(info, val);
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
+		return 0;
+	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		return rt9455_charger_get_term_current(info, val);
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = RT9455_MODEL_NAME;
+		return 0;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = RT9455_MANUFACTURER;
+		return 0;
+	default:
+		return -ENODATA;
+	}
+}
+
+static int rt9455_charger_set_current(struct rt9455_info *info,
+				      const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_ICHRG,
+				    rt9455_ichrg_values,
+				    ARRAY_SIZE(rt9455_ichrg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_voltage(struct rt9455_info *info,
+				      const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_VOREG,
+				    rt9455_voreg_values,
+				    ARRAY_SIZE(rt9455_voreg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
+					  const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_VMREG,
+				    rt9455_vmreg_values,
+				    ARRAY_SIZE(rt9455_vmreg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       const union power_supply_propval *val)
+{
+	struct rt9455_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return rt9455_charger_set_current(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return rt9455_charger_set_voltage(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return rt9455_charger_set_voltage_max(info, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int rt9455_charger_property_is_writeable(struct power_supply *psy,
+						enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int rt9455_hw_init(struct rt9455_info *info, u32 ichrg,
+			  u32 ieoc_percentage, u32 voreg,
+			  u32 mivr, u32 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	ret = rt9455_register_reset(info);
+	if (ret) {
+		dev_err(dev, "Power On Reset failed\n");
+		return ret;
+	}
+
+	/* Set TE bit in order to enable end of charge detection */
+	ret = regmap_field_write(info->regmap_fields[F_TE], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set TE bit\n");
+		return ret;
+	}
+
+	/* Set TE_SHDN_EN bit in order to enable end of charge detection */
+	ret = regmap_field_write(info->regmap_fields[F_TE_SHDN_EN], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set TE_SHDN_EN bit\n");
+		return ret;
+	}
+
+	/*
+	 * Set BATD_EN bit in order to enable battery detection
+	 * when charging is done
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_BATD_EN], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set BATD_EN bit\n");
+		return ret;
+	}
+
+	/*
+	 * Disable Safety Timer. In charge mode, this timer terminates charging
+	 * if no read or write via I2C is done within 32 minutes. This timer
+	 * avoids overcharging the baterry when the OS is not loaded and the
+	 * charger is connected to a power source.
+	 * In boost mode, this timer triggers BST32SI interrupt if no read or
+	 * write via I2C is done within 32 seconds.
+	 * When the OS is loaded and the charger driver is inserted, we use
+	 * delayed_work, named max_charging_time_work, to avoid overcharging
+	 * the battery.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_TMR_EN], 0x00);
+	if (ret) {
+		dev_err(dev, "Failed to disable Safety Timer\n");
+		return ret;
+	}
+
+	/* Set ICHRG to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values), ichrg);
+	if (ret) {
+		dev_err(dev, "Failed to set ICHRG value\n");
+		return ret;
+	}
+
+	/* Set IEOC Percentage to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_IEOC_PERCENTAGE,
+				   rt9455_ieoc_percentage_values,
+				   ARRAY_SIZE(rt9455_ieoc_percentage_values),
+				   ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Failed to set IEOC Percentage value\n");
+		return ret;
+	}
+
+	/* Set VOREG to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_VOREG,
+				   rt9455_voreg_values,
+				   ARRAY_SIZE(rt9455_voreg_values), voreg);
+	if (ret) {
+		dev_err(dev, "Failed to set VOREG value\n");
+		return ret;
+	}
+
+	/*
+	 * Set VMREG value to maximum (4.45V). The charger uses VOREG as maximum
+	 * value for battery voltage, because charge termination is enabled.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_VMREG], 0x0F);
+
+	/*
+	 * Set MIVR to value retrieved from device-specific data.
+	 * If no value is specified, default value for MIVR is 4.5V.
+	 */
+	if (mivr == -1)
+		mivr = 4500000;
+
+	ret = rt9455_set_field_val(info, F_MIVR,
+				   rt9455_mivr_values,
+				   ARRAY_SIZE(rt9455_mivr_values), mivr);
+	if (ret) {
+		dev_err(dev, "Failed to set MIVR value\n");
+		return ret;
+	}
+
+	/*
+	 * Set IAICR to value retrieved from device-specific data.
+	 * If no value is specified, default value for IAICR is 500 mA.
+	 */
+	if (iaicr == -1)
+		iaicr = 500000;
+
+	ret = rt9455_set_field_val(info, F_IAICR,
+				   rt9455_iaicr_values,
+				   ARRAY_SIZE(rt9455_iaicr_values), iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to set IAICR value\n");
+		return ret;
+	}
+
+	/*
+	 * Set IAICR_INT bit so that IAICR value is determined by IAICR bits
+	 * and not by OTG pin.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_IAICR_INT], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to set IAICR_INT bit\n");
+		return ret;
+	}
+
+	/*
+	 * Disable CHMIVRI interrupt. Because the driver sets MIVR value,
+	 * CHMIVRI is triggered, but there is no action to be taken by the
+	 * driver when CHMIVRI is triggered.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_CHMIVRIM], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to mask CHMIVRI interrupt\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq1_register(struct rt9455_info *info,
+						  bool *_is_battery_absent,
+						  bool *_alert_userspace)
+{
+	unsigned int irq1, mask1, mask2;
+	struct device *dev = &info->client->dev;
+	bool is_battery_absent = false;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK1 register\n");
+		return ret;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_TSDI_MASK) {
+		dev_err(dev, "Thermal shutdown fault occurred\n");
+		alert_userspace = true;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_VINOVPI_MASK) {
+		dev_err(dev, "Overvoltage input occurred\n");
+		alert_userspace = true;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
+		dev_err(dev, "Battery absence occurred\n");
+		is_battery_absent = true;
+		alert_userspace = true;
+
+		if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 0) {
+			ret = regmap_field_write(info->regmap_fields[F_BATABM],
+						 0x01);
+			if (ret) {
+				dev_err(dev, "Failed to mask BATAB interrupt\n");
+				return ret;
+			}
+		}
+
+		ret = regmap_read(info->regmap, RT9455_REG_MASK2, &mask2);
+		if (ret) {
+			dev_err(dev, "Failed to read MASK2 register\n");
+			return ret;
+		}
+
+		if ((mask2 & RT9455_REG_MASK2_CHTERMIM_MASK)) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHTERMIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHTERMI interrupt\n");
+				return ret;
+			}
+		}
+
+		if ((mask2 & RT9455_REG_MASK2_CHRCHGIM_MASK)) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHRCHGIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHRCHGI interrupt\n");
+				return ret;
+			}
+		}
+
+		/*
+		 * When the battery is absent, max_charging_time_work is
+		 * cancelled, since no charging is done.
+		 */
+		cancel_delayed_work_sync(&info->max_charging_time_work);
+		/*
+		 * Since no interrupt is triggered when the battery is
+		 * reconnected, max_charging_time_work is not rescheduled.
+		 * Therefore, batt_presence_work is scheduled to check whether
+		 * the battery is still absent or not.
+		 */
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->batt_presence_work,
+				   RT9455_BATT_PRESENCE_DELAY * HZ);
+	}
+
+	*_is_battery_absent = is_battery_absent;
+
+	if (alert_userspace)
+		*_alert_userspace = alert_userspace;
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq2_register(struct rt9455_info *info,
+						  bool is_battery_absent,
+						  bool *_alert_userspace)
+{
+	unsigned int irq2, mask2;
+	struct device *dev = &info->client->dev;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ2, &irq2);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ2 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK2, &mask2);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK2 register\n");
+		return ret;
+	}
+
+	if (irq2 & RT9455_REG_IRQ2_CHRVPI_MASK) {
+		dev_dbg(dev, "Charger fault occurred\n");
+		alert_userspace = true;
+		/*
+		 * CHRVPI bit is set in 2 cases:
+		 * 1. when the power source is connected to the charger.
+		 * 2. when the power source is disconnected from the charger.
+		 * To identify the case, PWR_RDY bit is checked. Because
+		 * PWR_RDY bit is set / cleared after CHRVPI interrupt is
+		 * triggered, we use delayed_work to later read PWR_RDY bit.
+		 */
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->pwr_rdy_work,
+				   RT9455_PWR_RDY_DELAY * HZ);
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHBATOVI_MASK) {
+		dev_err(dev, "Battery OVP occurred\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHTERMI_MASK) {
+		dev_info(dev, "Charge terminated\n");
+		if (!is_battery_absent) {
+			if ((mask2 & RT9455_REG_MASK2_CHTERMIM_MASK) == 0) {
+				ret = regmap_field_write(
+					info->regmap_fields[F_CHTERMIM], 0x01);
+				if (ret) {
+					dev_err(dev, "Failed to mask CHTERMI interrupt\n");
+					return ret;
+				}
+				/*
+				 * Update MASK2 value, since we set CHTERMIM
+				 * bit.
+				 */
+				mask2 = mask2 | RT9455_REG_MASK2_CHTERMIM_MASK;
+			}
+			cancel_delayed_work_sync(&info->max_charging_time_work);
+			alert_userspace = true;
+		}
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHRCHGI_MASK) {
+		dev_info(dev, "Recharge request\n");
+		ret = regmap_field_write(info->regmap_fields[F_CHG_EN], 0x01);
+		if (ret) {
+			dev_err(dev, "Failed to enable charging\n");
+			return ret;
+		}
+		if (mask2 & RT9455_REG_MASK2_CHTERMIM_MASK) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHTERMIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHTERMI interrupt\n");
+				return ret;
+			}
+			/* Update MASK2 value, since we reset CHTERMIM bit. */
+			mask2 = mask2 & ~RT9455_REG_MASK2_CHTERMIM_MASK;
+		}
+		if (!is_battery_absent) {
+			/*
+			 * No need to check whether the charger is connected to
+			 * power source when CHRCHGI is received, since CHRCHGI
+			 * is not triggered if the charger is not connected to
+			 * the power source.
+			 */
+			queue_delayed_work(system_power_efficient_wq,
+					   &info->max_charging_time_work,
+					   RT9455_MAX_CHARGING_TIME * HZ);
+			alert_userspace = true;
+		}
+	}
+	if (irq2 & RT9455_REG_IRQ2_CH32MI_MASK) {
+		dev_err(dev, "Charger fault. 32 mins timeout occurred\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHTREGI_MASK) {
+		dev_warn(dev,
+			 "Charger warning. Thermal regulation loop active\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHMIVRI_MASK) {
+		dev_dbg(dev,
+			"Charger warning. Input voltage MIVR loop active\n");
+	}
+
+	if (alert_userspace)
+		*_alert_userspace = alert_userspace;
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq3_register(struct rt9455_info *info,
+						  bool *_alert_userspace)
+{
+	unsigned int irq3, mask3;
+	struct device *dev = &info->client->dev;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ3, &irq3);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ3 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK3, &mask3);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK3 register\n");
+		return ret;
+	}
+
+	if (irq3 & RT9455_REG_IRQ3_BSTBUSOVI_MASK) {
+		dev_err(dev, "Boost fault. Overvoltage input occurred\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BSTOLI_MASK) {
+		dev_err(dev, "Boost fault. Overload\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BSTLOWVI_MASK) {
+		dev_err(dev, "Boost fault. Battery voltage too low\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BST32SI_MASK) {
+		dev_err(dev, "Boost fault. 32 seconds timeout occurred.\n");
+		alert_userspace = true;
+	}
+
+	if (alert_userspace) {
+		dev_info(dev, "Boost fault occurred, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return ret;
+		}
+		*_alert_userspace = alert_userspace;
+	}
+
+	return 0;
+}
+
+static irqreturn_t rt9455_irq_handler_thread(int irq, void *data)
+{
+	struct rt9455_info *info = data;
+	struct device *dev;
+	bool alert_userspace = false;
+	bool is_battery_absent = false;
+	unsigned int status;
+	int ret;
+
+	if (!info)
+		return IRQ_NONE;
+
+	dev = &info->client->dev;
+
+	if (irq != info->client->irq) {
+		dev_err(dev, "Interrupt is not for RT9455 charger\n");
+		return IRQ_NONE;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &status);
+	if (ret) {
+		dev_err(dev, "Failed to read STAT bits\n");
+		return IRQ_HANDLED;
+	}
+	dev_dbg(dev, "Charger status is %d\n", status);
+
+	/*
+	 * Each function that processes an IRQ register receives as output
+	 * parameter alert_userspace pointer. alert_userspace is set to true
+	 * in such a function only if an interrupt has occurred in the
+	 * respective interrupt register. This way, we avoid the following
+	 * case: interrupt occurs only in IRQ1 register,
+	 * rt9455_irq_handler_check_irq1_register() function sets to true
+	 * alert_userspace, but rt9455_irq_handler_check_irq2_register()
+	 * and rt9455_irq_handler_check_irq3_register() functions set to false
+	 * alert_userspace and power_supply_changed() is never called.
+	 */
+	ret = rt9455_irq_handler_check_irq1_register(info, &is_battery_absent,
+						     &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ1 register\n");
+		return IRQ_HANDLED;
+	}
+
+	ret = rt9455_irq_handler_check_irq2_register(info, is_battery_absent,
+						     &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ2 register\n");
+		return IRQ_HANDLED;
+	}
+
+	ret = rt9455_irq_handler_check_irq3_register(info, &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ3 register\n");
+		return IRQ_HANDLED;
+	}
+
+	if (alert_userspace) {
+		/*
+		 * Sometimes, an interrupt occurs while probe() function is
+		 * executing and power_supply_register() is not yet called.
+		 * Do not call power_supply_charged() in this case.
+		 */
+		if (!IS_ERR_OR_NULL(info->charger))
+			power_supply_changed(info->charger);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int rt9455_setup_irq(struct rt9455_info *info)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	/* Obtain IRQ GPIO */
+	info->gpiod_irq = devm_gpiod_get_index(dev, RT9455_IRQ_NAME, 0);
+	if (IS_ERR(info->gpiod_irq)) {
+		dev_err(dev, "Failed to get IRQ GPIO\n");
+		return PTR_ERR(info->gpiod_irq);
+	}
+
+	/* Configure IRQ GPIO */
+	ret = gpiod_direction_input(info->gpiod_irq);
+	if (ret) {
+		dev_err(dev, "Failed to set IRQ GPIO direction err = %d\n",
+			ret);
+		return ret;
+	}
+
+	/* Map the pin to an IRQ */
+	ret = gpiod_to_irq(info->gpiod_irq);
+	if (ret < 0) {
+		dev_err(dev, "Failed to associate GPIO with an IRQ err = %d\n",
+			ret);
+		return ret;
+	}
+
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n",
+		desc_to_gpio(info->gpiod_irq), ret);
+	info->client->irq = ret;
+	info->gpio_irq = desc_to_gpio(info->gpiod_irq);
+
+	return 0;
+}
+
+static int rt9455_discover_charger(struct rt9455_info *info, u32 *ichrg,
+				   u32 *ieoc_percentage, u32 *voreg,
+				   u32 *mivr, u32 *iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (!dev->of_node && !ACPI_HANDLE(dev)) {
+		dev_err(dev, "No support for either device tree or ACPI\n");
+		return -EINVAL;
+	}
+	/* ICHRG, IEOC_PERCENTAGE and VOREG are mandatory parameters. */
+	ret = device_property_read_u32(dev, "richtek,output-charge-current",
+				       ichrg);
+	if (ret) {
+		dev_err(dev, "Error: missing \"output-charge-current\" property\n");
+		return ret;
+	}
+
+	ret = device_property_read_u32(dev, "richtek,end-of-charge-percentage",
+				       ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Error: missing \"end-of-charge-percentage\" property\n");
+		return ret;
+	}
+
+	ret = device_property_read_u32(dev,
+				       "richtek,battery-regulation-voltage",
+				       voreg);
+	if (ret) {
+		dev_err(dev, "Error: missing \"battery-regulation-voltage\" property\n");
+		return ret;
+	}
+
+	/*
+	 * MIVR and IAICR are optional parameters. Do not return error if one
+	 * of them is not present in ACPI table or device tree specification.
+	 */
+	device_property_read_u32(dev, "richtek,min-input-voltage-regulation",
+				 mivr);
+	device_property_read_u32(dev, "richtek,avg-input-current-regulation",
+				 iaicr);
+
+	ret = rt9455_setup_irq(info);
+	if (ret) {
+		dev_err(dev, "Failed to allocate IRQ resource\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rt9455_usb_event_none(struct rt9455_info *info,
+				 u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_NONE, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_NONE received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_NONE received, therefore IAICR is set to its minimum value\n");
+	if (iaicr != RT9455_IAICR_100MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_100MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_vbus(struct rt9455_info *info,
+				 u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_VBUS, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_VBUS received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_VBUS received, therefore IAICR is set to 500 mA\n");
+	if (iaicr != RT9455_IAICR_500MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_500MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_id(struct rt9455_info *info,
+			       u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_CHARGE_MODE) {
+		/*
+		 * If the charger is in charge mode, and it has received
+		 * USB_EVENT_ID, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_ID received, therefore the charger goes into boost mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_BOOST_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in boost mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_ID received, therefore IAICR is set to its minimum value\n");
+	if (iaicr != RT9455_IAICR_100MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_100MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_charger(struct rt9455_info *info,
+				    u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_CHARGER, this means the consumer device powered by
+		 * the charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_CHARGER received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_CHARGER received, therefore IAICR is set to no current limit\n");
+	if (iaicr != RT9455_IAICR_NO_LIMIT) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_NO_LIMIT);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event(struct notifier_block *nb,
+			    unsigned long event, void *power)
+{
+	struct rt9455_info *info = container_of(nb, struct rt9455_info, nb);
+	struct device *dev = &info->client->dev;
+	unsigned int opa_mode, iaicr;
+	int ret;
+
+	if (!info)
+		return NOTIFY_DONE;
+
+	/*
+	 * Determine whether the charger is in charge mode
+	 * or in boost mode.
+	 */
+	ret = regmap_field_read(info->regmap_fields[F_OPA_MODE],
+				&opa_mode);
+	if (ret) {
+		dev_err(dev, "Failed to read operation mode value\n");
+		return NOTIFY_DONE;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_IAICR],
+				&iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to read IAICR value\n");
+		return NOTIFY_DONE;
+	}
+
+	dev_dbg(dev, "Received USB event %lu\n", event);
+	switch (event) {
+	case USB_EVENT_NONE:
+		return rt9455_usb_event_none(info, opa_mode, iaicr);
+	case USB_EVENT_VBUS:
+		return rt9455_usb_event_vbus(info, opa_mode, iaicr);
+	case USB_EVENT_ID:
+		return rt9455_usb_event_id(info, opa_mode, iaicr);
+	case USB_EVENT_CHARGER:
+		return rt9455_usb_event_charger(info, opa_mode, iaicr);
+	default:
+		dev_err(dev, "Unknown USB event\n");
+	}
+	return NOTIFY_DONE;
+}
+
+static void rt9455_pwr_rdy_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						pwr_rdy_work.work);
+	struct device *dev = &info->client->dev;
+	unsigned int pwr_rdy;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_PWR_RDY], &pwr_rdy);
+	if (ret) {
+		dev_err(dev, "Failed to read PWR_RDY bit\n");
+		return;
+	}
+	switch (pwr_rdy) {
+	case RT9455_PWR_FAULT:
+		dev_dbg(dev, "Charger disconnected from power source\n");
+		cancel_delayed_work_sync(&info->max_charging_time_work);
+		break;
+	case RT9455_PWR_GOOD:
+		dev_dbg(dev, "Charger connected to power source\n");
+		ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
+					 RT9455_CHARGE_ENABLE);
+		if (ret) {
+			dev_err(dev, "Failed to enable charging\n");
+			return;
+		}
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->max_charging_time_work,
+				   RT9455_MAX_CHARGING_TIME * HZ);
+		break;
+	}
+}
+
+static void rt9455_max_charging_time_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						max_charging_time_work.work);
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	dev_err(dev, "Battery has been charging for at least 6 hours and is not yet fully charged. Battery is dead, therefore charging is disabled.\n");
+	ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
+				 RT9455_CHARGE_DISABLE);
+	if (ret)
+		dev_err(dev, "Failed to disable charging\n");
+}
+
+static void rt9455_batt_presence_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						batt_presence_work.work);
+	struct device *dev = &info->client->dev;
+	unsigned int irq1, mask1;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return;
+	}
+
+	/*
+	 * If the battery is still absent, batt_presence_work is rescheduled.
+	 * Otherwise, max_charging_time is scheduled.
+	 */
+	if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->batt_presence_work,
+				   RT9455_BATT_PRESENCE_DELAY * HZ);
+	} else {
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->max_charging_time_work,
+				   RT9455_MAX_CHARGING_TIME * HZ);
+
+		ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
+		if (ret) {
+			dev_err(dev, "Failed to read MASK1 register\n");
+			return;
+		}
+
+		if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 1) {
+			ret = regmap_field_write(info->regmap_fields[F_BATABM],
+						 0x00);
+			if (ret)
+				dev_err(dev, "Failed to unmask BATAB interrupt\n");
+		}
+	}
+}
+
+static const struct power_supply_desc rt9455_charger_desc = {
+	.name			= RT9455_DRIVER_NAME,
+	.type			= POWER_SUPPLY_TYPE_USB,
+	.properties		= rt9455_charger_properties,
+	.num_properties		= ARRAY_SIZE(rt9455_charger_properties),
+	.get_property		= rt9455_charger_get_property,
+	.set_property		= rt9455_charger_set_property,
+	.property_is_writeable	= rt9455_charger_property_is_writeable,
+};
+
+static int rt9455_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct device *dev = &client->dev;
+	struct rt9455_info *info;
+	struct power_supply_config rt9455_charger_config = {};
+	/* mandatory device-specific data values */
+	u32 ichrg, ieoc_percentage, voreg;
+	/* optional device-specific data values */
+	u32 mivr = -1, iaicr = -1;
+	int i, ret;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
+		return -ENODEV;
+	}
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->client = client;
+	i2c_set_clientdata(client, info);
+
+	info->regmap = devm_regmap_init_i2c(client,
+					    &rt9455_regmap_config);
+	if (IS_ERR(info->regmap)) {
+		dev_err(dev, "Failed to initialize register map\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		info->regmap_fields[i] =
+			devm_regmap_field_alloc(dev, info->regmap,
+						rt9455_reg_fields[i]);
+		if (IS_ERR(info->regmap_fields[i])) {
+			dev_err(dev,
+				"Failed to allocate regmap field = %d\n", i);
+			return PTR_ERR(info->regmap_fields[i]);
+		}
+	}
+
+	ret = rt9455_discover_charger(info, &ichrg, &ieoc_percentage,
+				      &voreg, &mivr, &iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to discover charger\n");
+		return ret;
+	}
+
+#if IS_ENABLED(CONFIG_USB_PHY)
+	info->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
+	if (IS_ERR_OR_NULL(info->usb_phy)) {
+		dev_err(dev, "Failed to get USB transceiver\n");
+	} else {
+		info->nb.notifier_call = rt9455_usb_event;
+		ret = usb_register_notifier(info->usb_phy, &info->nb);
+		if (ret) {
+			dev_err(dev, "Failed to register USB notifier\n");
+			usb_put_phy(info->usb_phy);
+		}
+	}
+#endif
+
+	INIT_DELAYED_WORK(&info->pwr_rdy_work, rt9455_pwr_rdy_work_callback);
+	INIT_DELAYED_WORK(&info->max_charging_time_work,
+			  rt9455_max_charging_time_work_callback);
+	INIT_DELAYED_WORK(&info->batt_presence_work,
+			  rt9455_batt_presence_work_callback);
+
+	rt9455_charger_config.of_node		= dev->of_node;
+	rt9455_charger_config.drv_data		= info;
+	rt9455_charger_config.supplied_to	= rt9455_charger_supplied_to;
+	rt9455_charger_config.num_supplicants	=
+					ARRAY_SIZE(rt9455_charger_supplied_to);
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					rt9455_irq_handler_thread,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					RT9455_DRIVER_NAME, info);
+	if (ret < 0) {
+		dev_err(dev, "Failed to register IRQ handler\n");
+		return ret;
+	}
+
+	ret = rt9455_hw_init(info, ichrg, ieoc_percentage, voreg, mivr, iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to set charger to its default values\n");
+		return ret;
+	}
+
+	info->charger = power_supply_register(dev, &rt9455_charger_desc,
+					      &rt9455_charger_config);
+	if (IS_ERR(info->charger)) {
+		dev_err(dev, "Failed to register charger\n");
+		ret = PTR_ERR(info->charger);
+		goto put_usb_phy;
+	}
+
+	return 0;
+
+put_usb_phy:
+#if IS_ENABLED(CONFIG_USB_PHY)
+	if (!IS_ERR_OR_NULL(info->usb_phy))  {
+		usb_unregister_notifier(info->usb_phy, &info->nb);
+		usb_put_phy(info->usb_phy);
+	}
+#endif
+	return ret;
+}
+
+static int rt9455_remove(struct i2c_client *client)
+{
+	int ret;
+	struct rt9455_info *info = i2c_get_clientdata(client);
+
+	ret = rt9455_register_reset(info);
+	if (ret)
+		dev_err(&info->client->dev, "Failed to set charger to its default values\n");
+
+#if IS_ENABLED(CONFIG_USB_PHY)
+	if (!IS_ERR_OR_NULL(info->usb_phy)) {
+		usb_unregister_notifier(info->usb_phy, &info->nb);
+		usb_put_phy(info->usb_phy);
+	}
+#endif
+
+	cancel_delayed_work_sync(&info->pwr_rdy_work);
+	cancel_delayed_work_sync(&info->max_charging_time_work);
+	cancel_delayed_work_sync(&info->batt_presence_work);
+
+	power_supply_unregister(info->charger);
+
+	return ret;
+}
+
+static const struct i2c_device_id rt9455_i2c_id_table[] = {
+	{ RT9455_DRIVER_NAME, 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, rt9455_i2c_id_table);
+
+static const struct of_device_id rt9455_of_match[] = {
+	{ .compatible = "richtek,rt9455", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rt9455_of_match);
+
+static const struct acpi_device_id rt9455_i2c_acpi_match[] = {
+	{ "RT945500", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, rt9455_i2c_acpi_match);
+
+static struct i2c_driver rt9455_driver = {
+	.probe		= rt9455_probe,
+	.remove		= rt9455_remove,
+	.id_table	= rt9455_i2c_id_table,
+	.driver = {
+		.name		= RT9455_DRIVER_NAME,
+		.of_match_table	= of_match_ptr(rt9455_of_match),
+		.acpi_match_table = ACPI_PTR(rt9455_i2c_acpi_match),
+	},
+};
+module_i2c_driver(rt9455_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anda-Maria Nicolae <anda-maria.nicolae@intel.com>");
+MODULE_ALIAS("i2c:rt9455-charger");
+MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
-- 
1.7.9.5


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
@ 2015-04-29 20:13 ` Anda-Maria Nicolae
  0 siblings, 0 replies; 8+ messages in thread
From: Anda-Maria Nicolae @ 2015-04-29 20:13 UTC (permalink / raw)
  To: sre-DgEjT+Ai2ygdnm+yROfE0A, dbaryshkov-Re5JQEeQqe8AvxtiuMwx3w,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A, pawel.moll-5wv7dgnIgG8,
	mark.rutland-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg,
	galak-sgV2jX0FEOL9JmXXK+q4OQ, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ,
	linux-pm-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	devicetree-u79uwXL29TY76Z2rM5mHXA

Based on the datasheet found here:
http://www.richtek.com/download_ds.jsp?p=RT9455

Updates from the previous version:
- replaced license GPLv2 with GPL
- replaced vendor prefix rt with richtek
- replaced uppercase properties names from devicetree with lowercase separated by dash properties names
- replaced I/O read/write API with regmap_read/write and regmap_field_read/write
- used kernel multiline comment
- used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.
- replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc 
- replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
- replaced {"RTK9455", 0} with { "RTK9455", 0 }
- removed .owner = THIS_MODULE

Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/power/rt9455_charger.txt   |   43 +
 .../devicetree/bindings/vendor-prefixes.txt        |    1 +
 drivers/power/Kconfig                              |    6 +
 drivers/power/Makefile                             |    1 +
 drivers/power/rt9455_charger.c                     | 1758 ++++++++++++++++++++
 5 files changed, 1809 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/rt9455_charger.txt
 create mode 100644 drivers/power/rt9455_charger.c

diff --git a/Documentation/devicetree/bindings/power/rt9455_charger.txt b/Documentation/devicetree/bindings/power/rt9455_charger.txt
new file mode 100644
index 0000000..7e8aed6
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/rt9455_charger.txt
@@ -0,0 +1,43 @@
+Binding for Richtek rt9455 battery charger
+
+Required properties:
+- compatible: Should contain one of the following:
+ * "richtek,rt9455"
+
+- reg:					integer, i2c address of the device.
+- richtek,output-charge-current:	integer, output current from the charger to the
+					battery, in uA.
+- richtek,end-of-charge-percentage:	integer, percent of the output charge current.
+					When the current in constant-voltage phase drops
+					below output_charge_current x end-of-charge-percentage,
+					charge is terminated.
+- richtek,battery-regulation-voltage:	integer, maximum battery voltage in uV.
+
+Optional properties:
+- richtek,min-input-voltage-regulation: integer, input voltage level in uA, used to
+					decrease voltage level when the over current
+					of the input power source occurs.
+					This prevents input voltage drop due to insufficient
+					current provided by the power source.
+- richtek,avg-input-current-regulation: integer, input current value drained by the
+					charger from the power source.
+
+Example:
+
+rt9455@22 {
+	compatible = "richtek,rt9455";
+	reg = <0x22>;
+
+	interrupt-parent = <&gpio1>;
+	interrupts = <0 1>;
+
+	interrupt-gpio = <&gpio1 0 1>;
+	reset-gpio = <&gpio1 1 1>;
+
+	richtek,output-charge-current	    = <500000>;
+	richtek,end-of-charge-percentage    = <10>;
+	richtek,battery-regulation-voltage  = <4200000>;
+
+	richtek,min-input-voltage-regulation = <4500000>;
+	richtek,avg-input-current-regulation = <500000>;
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 389ca13..92a9508 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -148,6 +148,7 @@ raidsonic	RaidSonic Technology GmbH
 ralink	Mediatek/Ralink Technology Corp.
 ramtron	Ramtron International
 realtek Realtek Semiconductor Corp.
+richtek	Richtek Technology Corporation
 renesas	Renesas Electronics Corporation
 ricoh	Ricoh Co. Ltd.
 rockchip	Fuzhou Rockchip Electronics Co., Ltd
diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 4091fb0..39f208d 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -439,6 +439,12 @@ config BATTERY_RT5033
 	  The fuelgauge calculates and determines the battery state of charge
 	  according to battery open circuit voltage.
 
+config CHARGER_RT9455
+	tristate "Richtek RT9455 battery charger driver"
+	depends on I2C && GPIOLIB
+	help
+	Say Y to enable support for the Richtek RT9455 battery charger.
+
 source "drivers/power/reset/Kconfig"
 
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index b7b0181..e49abbf 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_MAX17042)	+= max17042_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
 obj-$(CONFIG_BATTERY_RT5033)	+= rt5033_battery.o
+obj-$(CONFIG_CHARGER_RT9455)	+= rt9455_charger.o
 obj-$(CONFIG_BATTERY_S3C_ADC)	+= s3c_adc_battery.o
 obj-$(CONFIG_BATTERY_TWL4030_MADC)	+= twl4030_madc_battery.o
 obj-$(CONFIG_CHARGER_88PM860X)	+= 88pm860x_charger.o
diff --git a/drivers/power/rt9455_charger.c b/drivers/power/rt9455_charger.c
new file mode 100644
index 0000000..e45b0f2
--- /dev/null
+++ b/drivers/power/rt9455_charger.c
@@ -0,0 +1,1758 @@
+/*
+ * Driver for Richtek RT9455WSC battery charger.
+ *
+ * Copyright (C) 2015 Intel Corporation
+ *
+ * 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/interrupt.h>
+#include <linux/delay.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/usb/phy.h>
+#include <linux/regmap.h>
+
+#define RT9455_MANUFACTURER			"Richtek"
+#define RT9455_MODEL_NAME			"RT9455"
+#define RT9455_DRIVER_NAME			"rt9455-charger"
+
+#define RT9455_IRQ_NAME				"interrupt"
+
+#define RT9455_PWR_RDY_DELAY			1 /* 1 second */
+#define RT9455_MAX_CHARGING_TIME		21600 /* 6 hrs */
+#define RT9455_BATT_PRESENCE_DELAY		60 /* 60 seconds */
+
+#define RT9455_CHARGE_MODE			0x00
+#define RT9455_BOOST_MODE			0x01
+
+#define RT9455_FAULT				0x03
+
+#define RT9455_IAICR_100MA			0x00
+#define RT9455_IAICR_500MA			0x01
+#define RT9455_IAICR_NO_LIMIT			0x03
+
+#define RT9455_CHARGE_DISABLE			0x00
+#define RT9455_CHARGE_ENABLE			0x01
+
+#define RT9455_PWR_FAULT			0x00
+#define RT9455_PWR_GOOD				0x01
+
+#define RT9455_REG_CTRL1			0x00 /* CTRL1 reg address */
+#define RT9455_REG_CTRL1_STAT_MASK		(BIT(5) | BIT(4))
+#define RT9455_REG_CTRL1_BOOST_MASK		BIT(3)
+#define RT9455_REG_CTRL1_PWR_RDY_MASK		BIT(2)
+#define RT9455_REG_CTRL1_OTG_PIN_POLARITY_MASK	BIT(1)
+
+#define RT9455_REG_CTRL2			0x01 /* CTRL2 reg address */
+#define RT9455_REG_CTRL2_IAICR_MASK		(BIT(7) | BIT(6))
+#define RT9455_REG_CTRL2_TE_SHDN_EN_MASK	BIT(5)
+#define RT9455_REG_CTRL2_HIGHER_OCP_MASK	BIT(4)
+#define RT9455_REG_CTRL2_TE_MASK		BIT(3)
+#define RT9455_REG_CTRL2_IAICR_INT_MASK		BIT(2)
+#define RT9455_REG_CTRL2_HIZ_MASK		BIT(1)
+#define RT9455_REG_CTRL2_OPA_MODE_MASK		BIT(0)
+
+#define RT9455_REG_CTRL3			0x02 /* CTRL3 reg address */
+#define RT9455_REG_CTRL3_VOREG_MASK		(BIT(7) | BIT(6) | BIT(5) | \
+						 BIT(4) | BIT(3) | BIT(2))
+#define RT9455_REG_CTRL3_OTG_PL_MASK		BIT(1)
+#define RT9455_REG_CTRL3_OTG_EN_MASK		BIT(0)
+
+#define RT9455_REG_DEV_ID			0x03 /* DEV_ID reg address */
+#define RT9455_REG_DEV_ID_VENDOR_ID_MASK	(BIT(7) | BIT(6) | BIT(5) | \
+						 BIT(4))
+#define RT9455_REG_DEV_ID_CHIP_REV_MASK		(BIT(3) | BIT(2) | BIT(1) | \
+						 BIT(0))
+
+#define RT9455_REG_CTRL4			0x04 /* CTRL4 reg address */
+#define RT9455_REG_CTRL4_RST_MASK		BIT(7)
+
+#define RT9455_REG_CTRL5			0x05 /* CTRL5 reg address */
+#define RT9455_REG_CTRL5_TMR_EN_MASK		BIT(7)
+#define RT9455_REG_CTRL5_MIVR_MASK		(BIT(5) | BIT(4))
+#define RT9455_REG_CTRL5_IPREC_MASK		(BIT(3) | BIT(2))
+#define RT9455_REG_CTRL5_IEOC_PERCENTAGE_MASK	(BIT(1) | BIT(0))
+
+#define RT9455_REG_CTRL6			0x06 /* CTRL6 reg address */
+#define RT9455_REG_CTRL6_IAICR_SEL_MASK		BIT(7)
+#define RT9455_REG_CTRL6_ICHRG_MASK		(BIT(6) | BIT(5) | BIT(4))
+#define RT9455_REG_CTRL6_VPREC_MASK		(BIT(2) | BIT(1) | BIT(0))
+
+#define RT9455_REG_CTRL7			0x07 /* CTRL7 reg address */
+#define RT9455_REG_CTRL7_BATD_EN_MASK		BIT(6)
+#define RT9455_REG_CTRL7_CHG_EN_MASK		BIT(4)
+#define RT9455_REG_CTRL7_VMREG_MASK		(BIT(3) | BIT(2) | BIT(1) | \
+						 BIT(0))
+
+#define RT9455_REG_IRQ1				0x08 /* IRQ1 reg address */
+#define RT9455_REG_IRQ1_TSDI_MASK		BIT(7)
+#define RT9455_REG_IRQ1_VINOVPI_MASK		BIT(6)
+#define RT9455_REG_IRQ1_BATAB_MASK		BIT(0)
+
+#define RT9455_REG_IRQ2				0x09 /* IRQ2 reg address */
+#define RT9455_REG_IRQ2_CHRVPI_MASK		BIT(7)
+#define RT9455_REG_IRQ2_CHBATOVI_MASK		BIT(5)
+#define RT9455_REG_IRQ2_CHTERMI_MASK		BIT(4)
+#define RT9455_REG_IRQ2_CHRCHGI_MASK		BIT(3)
+#define RT9455_REG_IRQ2_CH32MI_MASK		BIT(2)
+#define RT9455_REG_IRQ2_CHTREGI_MASK		BIT(1)
+#define RT9455_REG_IRQ2_CHMIVRI_MASK		BIT(0)
+
+#define RT9455_REG_IRQ3				0x0A /* IRQ3 reg address */
+#define RT9455_REG_IRQ3_BSTBUSOVI_MASK		BIT(7)
+#define RT9455_REG_IRQ3_BSTOLI_MASK		BIT(6)
+#define RT9455_REG_IRQ3_BSTLOWVI_MASK		BIT(5)
+#define RT9455_REG_IRQ3_BST32SI_MASK		BIT(3)
+
+#define RT9455_REG_MASK1			0x0B /* MASK1 reg address */
+#define RT9455_REG_MASK1_TSDM_MASK		BIT(7)
+#define RT9455_REG_MASK1_VINOVPIM_MASK		BIT(6)
+#define RT9455_REG_MASK1_BATABM_MASK		BIT(0)
+
+#define RT9455_REG_MASK2			0x0C /* MASK2 reg address */
+#define RT9455_REG_MASK2_CHRVPIM_MASK		BIT(7)
+#define RT9455_REG_MASK2_CHBATOVIM_MASK		BIT(5)
+#define RT9455_REG_MASK2_CHTERMIM_MASK		BIT(4)
+#define RT9455_REG_MASK2_CHRCHGIM_MASK		BIT(3)
+#define RT9455_REG_MASK2_CH32MIM_MASK		BIT(2)
+#define RT9455_REG_MASK2_CHTREGIM_MASK		BIT(1)
+#define RT9455_REG_MASK2_CHMIVRIM_MASK		BIT(0)
+
+#define RT9455_REG_MASK3			0x0D /* MASK3 reg address */
+#define RT9455_REG_MASK3_BSTVINOVIM_MASK	BIT(7)
+#define RT9455_REG_MASK3_BSTOLIM_MASK		BIT(6)
+#define RT9455_REG_MASK3_BSTLOWVIM_MASK		BIT(5)
+#define RT9455_REG_MASK3_BST32SIM_MASK		BIT(3)
+
+enum rt9455_fields {
+	F_STAT, F_BOOST, F_PWR_RDY, F_OTG_PIN_POLARITY, /* CTRL1 reg fields */
+
+	F_IAICR, F_TE_SHDN_EN, F_HIGHER_OCP, F_TE, F_IAICR_INT, F_HIZ,
+	F_OPA_MODE, /* CTRL2 reg fields */
+
+	F_VOREG, F_OTG_PL, F_OTG_EN, /* CTRL3 reg fields */
+
+	F_VENDOR_ID, F_CHIP_REV, /* DEV_ID reg fields */
+
+	F_RST, /* CTRL4 reg fields */
+
+	F_TMR_EN, F_MIVR, F_IPREC, F_IEOC_PERCENTAGE, /* CTRL5 reg fields*/
+
+	F_IAICR_SEL, F_ICHRG, F_VPREC, /* CTRL6 reg fields */
+
+	F_BATD_EN, F_CHG_EN, F_VMREG, /* CTRL7 reg fields */
+
+	F_TSDI, F_VINOVPI, F_BATAB, /* IRQ1 reg fields */
+
+	F_CHRVPI, F_CHBATOVI, F_CHTERMI, F_CHRCHGI, F_CH32MI, F_CHTREGI,
+	F_CHMIVRI, /* IRQ2 reg fields */
+
+	F_BSTBUSOVI, F_BSTOLI, F_BSTLOWVI, F_BST32SI, /* IRQ3 reg fields */
+
+	F_TSDM, F_VINOVPIM, F_BATABM, /* MASK1 reg fields */
+
+	F_CHRVPIM, F_CHBATOVIM, F_CHTERMIM, F_CHRCHGIM, F_CH32MIM, F_CHTREGIM,
+	F_CHMIVRIM, /* MASK2 reg fields */
+
+	F_BSTVINOVIM, F_BSTOLIM, F_BSTLOWVIM, F_BST32SIM, /* MASK3 reg fields */
+
+	F_MAX_FIELDS
+};
+
+static const struct reg_field rt9455_reg_fields[] = {
+	[F_STAT]		= REG_FIELD(RT9455_REG_CTRL1, 4, 5),
+	[F_BOOST]		= REG_FIELD(RT9455_REG_CTRL1, 3, 3),
+	[F_PWR_RDY]		= REG_FIELD(RT9455_REG_CTRL1, 2, 2),
+	[F_OTG_PIN_POLARITY]	= REG_FIELD(RT9455_REG_CTRL1, 1, 1),
+
+	[F_IAICR]		= REG_FIELD(RT9455_REG_CTRL2, 6, 7),
+	[F_TE_SHDN_EN]		= REG_FIELD(RT9455_REG_CTRL2, 5, 5),
+	[F_HIGHER_OCP]		= REG_FIELD(RT9455_REG_CTRL2, 4, 4),
+	[F_TE]			= REG_FIELD(RT9455_REG_CTRL2, 3, 3),
+	[F_IAICR_INT]		= REG_FIELD(RT9455_REG_CTRL2, 2, 2),
+	[F_HIZ]			= REG_FIELD(RT9455_REG_CTRL2, 1, 1),
+	[F_OPA_MODE]		= REG_FIELD(RT9455_REG_CTRL2, 0, 0),
+
+	[F_VOREG]		= REG_FIELD(RT9455_REG_CTRL3, 2, 7),
+	[F_OTG_PL]		= REG_FIELD(RT9455_REG_CTRL3, 1, 1),
+	[F_OTG_EN]		= REG_FIELD(RT9455_REG_CTRL3, 0, 0),
+
+	[F_VENDOR_ID]		= REG_FIELD(RT9455_REG_DEV_ID, 4, 7),
+	[F_CHIP_REV]		= REG_FIELD(RT9455_REG_DEV_ID, 0, 3),
+
+	[F_RST]			= REG_FIELD(RT9455_REG_CTRL4, 7, 7),
+
+	[F_TMR_EN]		= REG_FIELD(RT9455_REG_CTRL5, 7, 7),
+	[F_MIVR]		= REG_FIELD(RT9455_REG_CTRL5, 4, 5),
+	[F_IPREC]		= REG_FIELD(RT9455_REG_CTRL5, 2, 3),
+	[F_IEOC_PERCENTAGE]	= REG_FIELD(RT9455_REG_CTRL5, 0, 1),
+
+	[F_IAICR_SEL]		= REG_FIELD(RT9455_REG_CTRL6, 7, 7),
+	[F_ICHRG]		= REG_FIELD(RT9455_REG_CTRL6, 4, 6),
+	[F_VPREC]		= REG_FIELD(RT9455_REG_CTRL6, 0, 2),
+
+	[F_BATD_EN]		= REG_FIELD(RT9455_REG_CTRL7, 6, 6),
+	[F_CHG_EN]		= REG_FIELD(RT9455_REG_CTRL7, 4, 4),
+	[F_VMREG]		= REG_FIELD(RT9455_REG_CTRL7, 0, 3),
+
+	[F_TSDI]		= REG_FIELD(RT9455_REG_IRQ1, 7, 7),
+	[F_VINOVPI]		= REG_FIELD(RT9455_REG_IRQ1, 6, 6),
+	[F_BATAB]		= REG_FIELD(RT9455_REG_IRQ1, 0, 0),
+
+	[F_CHRVPI]		= REG_FIELD(RT9455_REG_IRQ2, 7, 7),
+	[F_CHBATOVI]		= REG_FIELD(RT9455_REG_IRQ2, 5, 5),
+	[F_CHTERMI]		= REG_FIELD(RT9455_REG_IRQ2, 4, 4),
+	[F_CHRCHGI]		= REG_FIELD(RT9455_REG_IRQ2, 3, 3),
+	[F_CH32MI]		= REG_FIELD(RT9455_REG_IRQ2, 2, 2),
+	[F_CHTREGI]		= REG_FIELD(RT9455_REG_IRQ2, 1, 1),
+	[F_CHMIVRI]		= REG_FIELD(RT9455_REG_IRQ2, 0, 0),
+
+	[F_BSTBUSOVI]		= REG_FIELD(RT9455_REG_IRQ3, 7, 7),
+	[F_BSTOLI]		= REG_FIELD(RT9455_REG_IRQ3, 6, 6),
+	[F_BSTLOWVI]		= REG_FIELD(RT9455_REG_IRQ3, 5, 5),
+	[F_BST32SI]		= REG_FIELD(RT9455_REG_IRQ3, 3, 3),
+
+	[F_TSDM]		= REG_FIELD(RT9455_REG_MASK1, 7, 7),
+	[F_VINOVPIM]		= REG_FIELD(RT9455_REG_MASK1, 6, 6),
+	[F_BATABM]		= REG_FIELD(RT9455_REG_MASK1, 0, 0),
+
+	[F_CHRVPIM]		= REG_FIELD(RT9455_REG_MASK2, 7, 7),
+	[F_CHBATOVIM]		= REG_FIELD(RT9455_REG_MASK2, 5, 5),
+	[F_CHTERMIM]		= REG_FIELD(RT9455_REG_MASK2, 4, 4),
+	[F_CHRCHGIM]		= REG_FIELD(RT9455_REG_MASK2, 3, 3),
+	[F_CH32MIM]		= REG_FIELD(RT9455_REG_MASK2, 2, 2),
+	[F_CHTREGIM]		= REG_FIELD(RT9455_REG_MASK2, 1, 1),
+	[F_CHMIVRIM]		= REG_FIELD(RT9455_REG_MASK2, 0, 0),
+
+	[F_BSTVINOVIM]		= REG_FIELD(RT9455_REG_MASK3, 7, 7),
+	[F_BSTOLIM]		= REG_FIELD(RT9455_REG_MASK3, 6, 6),
+	[F_BSTLOWVIM]		= REG_FIELD(RT9455_REG_MASK3, 5, 5),
+	[F_BST32SIM]		= REG_FIELD(RT9455_REG_MASK3, 3, 3),
+};
+
+/*
+ * Each array initialised below shows the possible real-world values for a
+ * group of bits belonging to RT9455 registers. The arrays are sorted in
+ * ascending order. The index of each real-world value represents the value
+ * that is encoded in the group of bits belonging to RT9455 registers.
+ */
+/* REG06[6:4] (ICHRG) in uAh */
+static const int rt9455_ichrg_values[] = {
+	 500000,  650000,  800000,  950000, 1100000, 1250000, 1400000, 1550000
+};
+
+/* REG02[7:2] (VOREG) in uV */
+static const int rt9455_voreg_values[] = {
+	3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
+	3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
+	3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
+	3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
+	4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
+	4300000, 4330000, 4350000, 4370000, 4390000, 4410000, 4430000, 4450000,
+	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000,
+	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000
+};
+
+/* REG07[3:0] (VMREG) in uV */
+static const int rt9455_vmreg_values[] = {
+	4200000, 4220000, 4240000, 4260000, 4280000, 4300000, 4320000, 4340000,
+	4360000, 4380000, 4400000, 4430000, 4450000, 4450000, 4450000, 4450000
+};
+
+/* REG05[5:4] (IEOC_PERCENTAGE) */
+static const int rt9455_ieoc_percentage_values[] = {
+	10, 30, 20, 30
+};
+
+/* REG05[1:0] (MIVR) in uV */
+static const int rt9455_mivr_values[] = {
+	4000000, 4250000, 4500000, 5000000
+};
+
+/* REG05[1:0] (IAICR) in uA */
+static const int rt9455_iaicr_values[] = {
+	100000, 500000, 1000000, 2000000
+};
+
+struct rt9455_info {
+	struct i2c_client		*client;
+	struct regmap			*regmap;
+	struct regmap_field		*regmap_fields[F_MAX_FIELDS];
+	struct power_supply		*charger;
+#if IS_ENABLED(CONFIG_USB_PHY)
+	struct usb_phy			*usb_phy;
+	struct notifier_block		nb;
+#endif
+	struct gpio_desc		*gpiod_irq;
+	unsigned int			gpio_irq;
+	struct delayed_work		pwr_rdy_work;
+	struct delayed_work		max_charging_time_work;
+	struct delayed_work		batt_presence_work;
+};
+
+static const struct regmap_config rt9455_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RT9455_REG_MASK3,
+};
+
+/*
+ * Iterate through each element of the 'tbl' array until an element whose value
+ * is greater than v is found. Return the index of the respective element,
+ * or the index of the last element in the array, if no such element is found.
+ */
+static u8 rt9455_find_idx(const int tbl[], int tbl_size, int v)
+{
+	int i;
+
+	/*
+	 * No need to iterate until the last index in the table because
+	 * if no element greater than v is found in the table,
+	 * or if only the last element is greater than v,
+	 * function returns the index of the last element.
+	 */
+	for (i = 0; i < tbl_size - 1; i++)
+		if (v <= tbl[i])
+			return i;
+
+	return (tbl_size - 1);
+}
+
+static int rt9455_get_field_val(struct rt9455_info *info,
+				enum rt9455_fields field,
+				const int tbl[], int tbl_size, int *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[field], &v);
+	if (ret)
+		return ret;
+
+	v = (v >= tbl_size) ? (tbl_size - 1) : v;
+	*val = tbl[v];
+
+	return 0;
+}
+
+static int rt9455_set_field_val(struct rt9455_info *info,
+				enum rt9455_fields field,
+				const int tbl[], int tbl_size, int val)
+{
+	u8 idx = rt9455_find_idx(tbl, tbl_size, val);
+
+	return regmap_field_write(info->regmap_fields[field], idx);
+}
+
+static int rt9455_register_reset(struct rt9455_info *info)
+{
+	struct device *dev = &info->client->dev;
+	unsigned int v;
+	int ret, limit = 100;
+
+	ret = regmap_field_write(info->regmap_fields[F_RST], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to set RST bit\n");
+		return ret;
+	}
+
+	/*
+	 * To make sure that reset operation has finished, loop until RST bit
+	 * is set to 0.
+	 */
+	do {
+		ret = regmap_field_read(info->regmap_fields[F_RST], &v);
+		if (ret) {
+			dev_err(dev, "Failed to read RST bit\n");
+			return ret;
+		}
+
+		if (!v)
+			break;
+
+		usleep_range(10, 100);
+	} while (--limit);
+
+	if (!limit)
+		return -EIO;
+
+	return 0;
+}
+
+/* Charger power supply property routines */
+static enum power_supply_property rt9455_charger_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_ONLINE,
+	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_SCOPE,
+	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static char *rt9455_charger_supplied_to[] = {
+	"main-battery",
+};
+
+static int rt9455_charger_get_status(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read STAT bits\n");
+		return ret;
+	}
+
+	switch (v) {
+	case 0:
+		val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+	break;
+	case 1:
+		val->intval = POWER_SUPPLY_STATUS_CHARGING;
+	break;
+	case 2:
+		val->intval = POWER_SUPPLY_STATUS_FULL;
+	break;
+	default:
+		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+	break;
+	}
+
+	return 0;
+}
+
+static int rt9455_charger_get_health(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	struct device *dev = &info->client->dev;
+	unsigned int v;
+	int ret;
+
+	val->intval = POWER_SUPPLY_HEALTH_GOOD;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ1_TSDI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ1_VINOVPI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ1_BATAB_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ2, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ2 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ2_CHBATOVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ2_CH32MI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+		return 0;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ3, &v);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ3 register\n");
+		return ret;
+	}
+
+	if (v & RT9455_REG_IRQ3_BSTBUSOVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BSTOLI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BSTLOWVI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+	if (v & RT9455_REG_IRQ3_BST32SI_MASK) {
+		val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+		return 0;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
+	if (ret) {
+		dev_err(dev, "Failed to read STAT bits\n");
+		return ret;
+	}
+
+	if (v == RT9455_FAULT) {
+		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+		return 0;
+	}
+
+	return 0;
+}
+
+static int rt9455_charger_get_battery_presence(struct rt9455_info *info,
+					       union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_BATAB], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read BATAB bit\n");
+		return ret;
+	}
+
+	/*
+	 * Since BATAB is 1 when battery is NOT present and 0 otherwise,
+	 * we return !BATAB.
+	 */
+	val->intval = !v;
+
+	return 0;
+}
+
+static int rt9455_charger_get_online(struct rt9455_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_PWR_RDY], &v);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read PWR_RDY bit\n");
+		return ret;
+	}
+
+	val->intval = (int)v;
+
+	return 0;
+}
+
+static int rt9455_charger_get_current(struct rt9455_info *info,
+				      union power_supply_propval *val)
+{
+	int curr;
+	int ret;
+
+	ret = rt9455_get_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values),
+				   &curr);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read ICHRG value\n");
+		return ret;
+	}
+
+	val->intval = curr;
+
+	return 0;
+}
+
+static int rt9455_charger_get_current_max(struct rt9455_info *info,
+					  union power_supply_propval *val)
+{
+	int idx = ARRAY_SIZE(rt9455_ichrg_values) - 1;
+
+	val->intval = rt9455_ichrg_values[idx];
+
+	return 0;
+}
+
+static int rt9455_charger_get_voltage(struct rt9455_info *info,
+				      union power_supply_propval *val)
+{
+	int voltage;
+	int ret;
+
+	ret = rt9455_get_field_val(info, F_VOREG,
+				   rt9455_voreg_values,
+				   ARRAY_SIZE(rt9455_voreg_values),
+				   &voltage);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read VOREG value\n");
+		return ret;
+	}
+
+	val->intval = voltage;
+
+	return 0;
+}
+
+static int rt9455_charger_get_voltage_max(struct rt9455_info *info,
+					  union power_supply_propval *val)
+{
+	int idx = ARRAY_SIZE(rt9455_voreg_values) - 1;
+
+	val->intval = rt9455_voreg_values[idx];
+
+	return 0;
+}
+
+static int rt9455_charger_get_term_current(struct rt9455_info *info,
+					   union power_supply_propval *val)
+{
+	struct device *dev = &info->client->dev;
+	int ichrg, ieoc_percentage, ret;
+
+	ret = rt9455_get_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values),
+				   &ichrg);
+	if (ret) {
+		dev_err(dev, "Failed to read ICHRG value\n");
+		return ret;
+	}
+
+	ret = rt9455_get_field_val(info, F_IEOC_PERCENTAGE,
+				   rt9455_ieoc_percentage_values,
+				   ARRAY_SIZE(rt9455_ieoc_percentage_values),
+				   &ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Failed to read IEOC value\n");
+		return ret;
+	}
+
+	val->intval = ichrg * ieoc_percentage / 100;
+
+	return 0;
+}
+
+static int rt9455_charger_get_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       union power_supply_propval *val)
+{
+	struct rt9455_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		return rt9455_charger_get_status(info, val);
+	case POWER_SUPPLY_PROP_HEALTH:
+		return rt9455_charger_get_health(info, val);
+	case POWER_SUPPLY_PROP_PRESENT:
+		return rt9455_charger_get_battery_presence(info, val);
+	case POWER_SUPPLY_PROP_ONLINE:
+		return rt9455_charger_get_online(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return rt9455_charger_get_current(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		return rt9455_charger_get_current_max(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return rt9455_charger_get_voltage(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return rt9455_charger_get_voltage_max(info, val);
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
+		return 0;
+	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		return rt9455_charger_get_term_current(info, val);
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = RT9455_MODEL_NAME;
+		return 0;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = RT9455_MANUFACTURER;
+		return 0;
+	default:
+		return -ENODATA;
+	}
+}
+
+static int rt9455_charger_set_current(struct rt9455_info *info,
+				      const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_ICHRG,
+				    rt9455_ichrg_values,
+				    ARRAY_SIZE(rt9455_ichrg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_voltage(struct rt9455_info *info,
+				      const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_VOREG,
+				    rt9455_voreg_values,
+				    ARRAY_SIZE(rt9455_voreg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
+					  const union power_supply_propval *val)
+{
+	return rt9455_set_field_val(info, F_VMREG,
+				    rt9455_vmreg_values,
+				    ARRAY_SIZE(rt9455_vmreg_values),
+				    val->intval);
+}
+
+static int rt9455_charger_set_property(struct power_supply *psy,
+				       enum power_supply_property psp,
+				       const union power_supply_propval *val)
+{
+	struct rt9455_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return rt9455_charger_set_current(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return rt9455_charger_set_voltage(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return rt9455_charger_set_voltage_max(info, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int rt9455_charger_property_is_writeable(struct power_supply *psy,
+						enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static int rt9455_hw_init(struct rt9455_info *info, u32 ichrg,
+			  u32 ieoc_percentage, u32 voreg,
+			  u32 mivr, u32 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	ret = rt9455_register_reset(info);
+	if (ret) {
+		dev_err(dev, "Power On Reset failed\n");
+		return ret;
+	}
+
+	/* Set TE bit in order to enable end of charge detection */
+	ret = regmap_field_write(info->regmap_fields[F_TE], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set TE bit\n");
+		return ret;
+	}
+
+	/* Set TE_SHDN_EN bit in order to enable end of charge detection */
+	ret = regmap_field_write(info->regmap_fields[F_TE_SHDN_EN], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set TE_SHDN_EN bit\n");
+		return ret;
+	}
+
+	/*
+	 * Set BATD_EN bit in order to enable battery detection
+	 * when charging is done
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_BATD_EN], 1);
+	if (ret) {
+		dev_err(dev, "Failed to set BATD_EN bit\n");
+		return ret;
+	}
+
+	/*
+	 * Disable Safety Timer. In charge mode, this timer terminates charging
+	 * if no read or write via I2C is done within 32 minutes. This timer
+	 * avoids overcharging the baterry when the OS is not loaded and the
+	 * charger is connected to a power source.
+	 * In boost mode, this timer triggers BST32SI interrupt if no read or
+	 * write via I2C is done within 32 seconds.
+	 * When the OS is loaded and the charger driver is inserted, we use
+	 * delayed_work, named max_charging_time_work, to avoid overcharging
+	 * the battery.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_TMR_EN], 0x00);
+	if (ret) {
+		dev_err(dev, "Failed to disable Safety Timer\n");
+		return ret;
+	}
+
+	/* Set ICHRG to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_ICHRG,
+				   rt9455_ichrg_values,
+				   ARRAY_SIZE(rt9455_ichrg_values), ichrg);
+	if (ret) {
+		dev_err(dev, "Failed to set ICHRG value\n");
+		return ret;
+	}
+
+	/* Set IEOC Percentage to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_IEOC_PERCENTAGE,
+				   rt9455_ieoc_percentage_values,
+				   ARRAY_SIZE(rt9455_ieoc_percentage_values),
+				   ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Failed to set IEOC Percentage value\n");
+		return ret;
+	}
+
+	/* Set VOREG to value retrieved from device-specific data */
+	ret = rt9455_set_field_val(info, F_VOREG,
+				   rt9455_voreg_values,
+				   ARRAY_SIZE(rt9455_voreg_values), voreg);
+	if (ret) {
+		dev_err(dev, "Failed to set VOREG value\n");
+		return ret;
+	}
+
+	/*
+	 * Set VMREG value to maximum (4.45V). The charger uses VOREG as maximum
+	 * value for battery voltage, because charge termination is enabled.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_VMREG], 0x0F);
+
+	/*
+	 * Set MIVR to value retrieved from device-specific data.
+	 * If no value is specified, default value for MIVR is 4.5V.
+	 */
+	if (mivr == -1)
+		mivr = 4500000;
+
+	ret = rt9455_set_field_val(info, F_MIVR,
+				   rt9455_mivr_values,
+				   ARRAY_SIZE(rt9455_mivr_values), mivr);
+	if (ret) {
+		dev_err(dev, "Failed to set MIVR value\n");
+		return ret;
+	}
+
+	/*
+	 * Set IAICR to value retrieved from device-specific data.
+	 * If no value is specified, default value for IAICR is 500 mA.
+	 */
+	if (iaicr == -1)
+		iaicr = 500000;
+
+	ret = rt9455_set_field_val(info, F_IAICR,
+				   rt9455_iaicr_values,
+				   ARRAY_SIZE(rt9455_iaicr_values), iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to set IAICR value\n");
+		return ret;
+	}
+
+	/*
+	 * Set IAICR_INT bit so that IAICR value is determined by IAICR bits
+	 * and not by OTG pin.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_IAICR_INT], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to set IAICR_INT bit\n");
+		return ret;
+	}
+
+	/*
+	 * Disable CHMIVRI interrupt. Because the driver sets MIVR value,
+	 * CHMIVRI is triggered, but there is no action to be taken by the
+	 * driver when CHMIVRI is triggered.
+	 */
+	ret = regmap_field_write(info->regmap_fields[F_CHMIVRIM], 0x01);
+	if (ret) {
+		dev_err(dev, "Failed to mask CHMIVRI interrupt\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq1_register(struct rt9455_info *info,
+						  bool *_is_battery_absent,
+						  bool *_alert_userspace)
+{
+	unsigned int irq1, mask1, mask2;
+	struct device *dev = &info->client->dev;
+	bool is_battery_absent = false;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK1 register\n");
+		return ret;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_TSDI_MASK) {
+		dev_err(dev, "Thermal shutdown fault occurred\n");
+		alert_userspace = true;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_VINOVPI_MASK) {
+		dev_err(dev, "Overvoltage input occurred\n");
+		alert_userspace = true;
+	}
+
+	if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
+		dev_err(dev, "Battery absence occurred\n");
+		is_battery_absent = true;
+		alert_userspace = true;
+
+		if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 0) {
+			ret = regmap_field_write(info->regmap_fields[F_BATABM],
+						 0x01);
+			if (ret) {
+				dev_err(dev, "Failed to mask BATAB interrupt\n");
+				return ret;
+			}
+		}
+
+		ret = regmap_read(info->regmap, RT9455_REG_MASK2, &mask2);
+		if (ret) {
+			dev_err(dev, "Failed to read MASK2 register\n");
+			return ret;
+		}
+
+		if ((mask2 & RT9455_REG_MASK2_CHTERMIM_MASK)) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHTERMIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHTERMI interrupt\n");
+				return ret;
+			}
+		}
+
+		if ((mask2 & RT9455_REG_MASK2_CHRCHGIM_MASK)) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHRCHGIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHRCHGI interrupt\n");
+				return ret;
+			}
+		}
+
+		/*
+		 * When the battery is absent, max_charging_time_work is
+		 * cancelled, since no charging is done.
+		 */
+		cancel_delayed_work_sync(&info->max_charging_time_work);
+		/*
+		 * Since no interrupt is triggered when the battery is
+		 * reconnected, max_charging_time_work is not rescheduled.
+		 * Therefore, batt_presence_work is scheduled to check whether
+		 * the battery is still absent or not.
+		 */
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->batt_presence_work,
+				   RT9455_BATT_PRESENCE_DELAY * HZ);
+	}
+
+	*_is_battery_absent = is_battery_absent;
+
+	if (alert_userspace)
+		*_alert_userspace = alert_userspace;
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq2_register(struct rt9455_info *info,
+						  bool is_battery_absent,
+						  bool *_alert_userspace)
+{
+	unsigned int irq2, mask2;
+	struct device *dev = &info->client->dev;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ2, &irq2);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ2 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK2, &mask2);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK2 register\n");
+		return ret;
+	}
+
+	if (irq2 & RT9455_REG_IRQ2_CHRVPI_MASK) {
+		dev_dbg(dev, "Charger fault occurred\n");
+		alert_userspace = true;
+		/*
+		 * CHRVPI bit is set in 2 cases:
+		 * 1. when the power source is connected to the charger.
+		 * 2. when the power source is disconnected from the charger.
+		 * To identify the case, PWR_RDY bit is checked. Because
+		 * PWR_RDY bit is set / cleared after CHRVPI interrupt is
+		 * triggered, we use delayed_work to later read PWR_RDY bit.
+		 */
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->pwr_rdy_work,
+				   RT9455_PWR_RDY_DELAY * HZ);
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHBATOVI_MASK) {
+		dev_err(dev, "Battery OVP occurred\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHTERMI_MASK) {
+		dev_info(dev, "Charge terminated\n");
+		if (!is_battery_absent) {
+			if ((mask2 & RT9455_REG_MASK2_CHTERMIM_MASK) == 0) {
+				ret = regmap_field_write(
+					info->regmap_fields[F_CHTERMIM], 0x01);
+				if (ret) {
+					dev_err(dev, "Failed to mask CHTERMI interrupt\n");
+					return ret;
+				}
+				/*
+				 * Update MASK2 value, since we set CHTERMIM
+				 * bit.
+				 */
+				mask2 = mask2 | RT9455_REG_MASK2_CHTERMIM_MASK;
+			}
+			cancel_delayed_work_sync(&info->max_charging_time_work);
+			alert_userspace = true;
+		}
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHRCHGI_MASK) {
+		dev_info(dev, "Recharge request\n");
+		ret = regmap_field_write(info->regmap_fields[F_CHG_EN], 0x01);
+		if (ret) {
+			dev_err(dev, "Failed to enable charging\n");
+			return ret;
+		}
+		if (mask2 & RT9455_REG_MASK2_CHTERMIM_MASK) {
+			ret = regmap_field_write(
+				info->regmap_fields[F_CHTERMIM], 0x00);
+			if (ret) {
+				dev_err(dev, "Failed to unmask CHTERMI interrupt\n");
+				return ret;
+			}
+			/* Update MASK2 value, since we reset CHTERMIM bit. */
+			mask2 = mask2 & ~RT9455_REG_MASK2_CHTERMIM_MASK;
+		}
+		if (!is_battery_absent) {
+			/*
+			 * No need to check whether the charger is connected to
+			 * power source when CHRCHGI is received, since CHRCHGI
+			 * is not triggered if the charger is not connected to
+			 * the power source.
+			 */
+			queue_delayed_work(system_power_efficient_wq,
+					   &info->max_charging_time_work,
+					   RT9455_MAX_CHARGING_TIME * HZ);
+			alert_userspace = true;
+		}
+	}
+	if (irq2 & RT9455_REG_IRQ2_CH32MI_MASK) {
+		dev_err(dev, "Charger fault. 32 mins timeout occurred\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHTREGI_MASK) {
+		dev_warn(dev,
+			 "Charger warning. Thermal regulation loop active\n");
+		alert_userspace = true;
+	}
+	if (irq2 & RT9455_REG_IRQ2_CHMIVRI_MASK) {
+		dev_dbg(dev,
+			"Charger warning. Input voltage MIVR loop active\n");
+	}
+
+	if (alert_userspace)
+		*_alert_userspace = alert_userspace;
+
+	return 0;
+}
+
+static int rt9455_irq_handler_check_irq3_register(struct rt9455_info *info,
+						  bool *_alert_userspace)
+{
+	unsigned int irq3, mask3;
+	struct device *dev = &info->client->dev;
+	bool alert_userspace = false;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ3, &irq3);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ3 register\n");
+		return ret;
+	}
+
+	ret = regmap_read(info->regmap, RT9455_REG_MASK3, &mask3);
+	if (ret) {
+		dev_err(dev, "Failed to read MASK3 register\n");
+		return ret;
+	}
+
+	if (irq3 & RT9455_REG_IRQ3_BSTBUSOVI_MASK) {
+		dev_err(dev, "Boost fault. Overvoltage input occurred\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BSTOLI_MASK) {
+		dev_err(dev, "Boost fault. Overload\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BSTLOWVI_MASK) {
+		dev_err(dev, "Boost fault. Battery voltage too low\n");
+		alert_userspace = true;
+	}
+	if (irq3 & RT9455_REG_IRQ3_BST32SI_MASK) {
+		dev_err(dev, "Boost fault. 32 seconds timeout occurred.\n");
+		alert_userspace = true;
+	}
+
+	if (alert_userspace) {
+		dev_info(dev, "Boost fault occurred, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return ret;
+		}
+		*_alert_userspace = alert_userspace;
+	}
+
+	return 0;
+}
+
+static irqreturn_t rt9455_irq_handler_thread(int irq, void *data)
+{
+	struct rt9455_info *info = data;
+	struct device *dev;
+	bool alert_userspace = false;
+	bool is_battery_absent = false;
+	unsigned int status;
+	int ret;
+
+	if (!info)
+		return IRQ_NONE;
+
+	dev = &info->client->dev;
+
+	if (irq != info->client->irq) {
+		dev_err(dev, "Interrupt is not for RT9455 charger\n");
+		return IRQ_NONE;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_STAT], &status);
+	if (ret) {
+		dev_err(dev, "Failed to read STAT bits\n");
+		return IRQ_HANDLED;
+	}
+	dev_dbg(dev, "Charger status is %d\n", status);
+
+	/*
+	 * Each function that processes an IRQ register receives as output
+	 * parameter alert_userspace pointer. alert_userspace is set to true
+	 * in such a function only if an interrupt has occurred in the
+	 * respective interrupt register. This way, we avoid the following
+	 * case: interrupt occurs only in IRQ1 register,
+	 * rt9455_irq_handler_check_irq1_register() function sets to true
+	 * alert_userspace, but rt9455_irq_handler_check_irq2_register()
+	 * and rt9455_irq_handler_check_irq3_register() functions set to false
+	 * alert_userspace and power_supply_changed() is never called.
+	 */
+	ret = rt9455_irq_handler_check_irq1_register(info, &is_battery_absent,
+						     &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ1 register\n");
+		return IRQ_HANDLED;
+	}
+
+	ret = rt9455_irq_handler_check_irq2_register(info, is_battery_absent,
+						     &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ2 register\n");
+		return IRQ_HANDLED;
+	}
+
+	ret = rt9455_irq_handler_check_irq3_register(info, &alert_userspace);
+	if (ret) {
+		dev_err(dev, "Failed to handle IRQ3 register\n");
+		return IRQ_HANDLED;
+	}
+
+	if (alert_userspace) {
+		/*
+		 * Sometimes, an interrupt occurs while probe() function is
+		 * executing and power_supply_register() is not yet called.
+		 * Do not call power_supply_charged() in this case.
+		 */
+		if (!IS_ERR_OR_NULL(info->charger))
+			power_supply_changed(info->charger);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int rt9455_setup_irq(struct rt9455_info *info)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	/* Obtain IRQ GPIO */
+	info->gpiod_irq = devm_gpiod_get_index(dev, RT9455_IRQ_NAME, 0);
+	if (IS_ERR(info->gpiod_irq)) {
+		dev_err(dev, "Failed to get IRQ GPIO\n");
+		return PTR_ERR(info->gpiod_irq);
+	}
+
+	/* Configure IRQ GPIO */
+	ret = gpiod_direction_input(info->gpiod_irq);
+	if (ret) {
+		dev_err(dev, "Failed to set IRQ GPIO direction err = %d\n",
+			ret);
+		return ret;
+	}
+
+	/* Map the pin to an IRQ */
+	ret = gpiod_to_irq(info->gpiod_irq);
+	if (ret < 0) {
+		dev_err(dev, "Failed to associate GPIO with an IRQ err = %d\n",
+			ret);
+		return ret;
+	}
+
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n",
+		desc_to_gpio(info->gpiod_irq), ret);
+	info->client->irq = ret;
+	info->gpio_irq = desc_to_gpio(info->gpiod_irq);
+
+	return 0;
+}
+
+static int rt9455_discover_charger(struct rt9455_info *info, u32 *ichrg,
+				   u32 *ieoc_percentage, u32 *voreg,
+				   u32 *mivr, u32 *iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (!dev->of_node && !ACPI_HANDLE(dev)) {
+		dev_err(dev, "No support for either device tree or ACPI\n");
+		return -EINVAL;
+	}
+	/* ICHRG, IEOC_PERCENTAGE and VOREG are mandatory parameters. */
+	ret = device_property_read_u32(dev, "richtek,output-charge-current",
+				       ichrg);
+	if (ret) {
+		dev_err(dev, "Error: missing \"output-charge-current\" property\n");
+		return ret;
+	}
+
+	ret = device_property_read_u32(dev, "richtek,end-of-charge-percentage",
+				       ieoc_percentage);
+	if (ret) {
+		dev_err(dev, "Error: missing \"end-of-charge-percentage\" property\n");
+		return ret;
+	}
+
+	ret = device_property_read_u32(dev,
+				       "richtek,battery-regulation-voltage",
+				       voreg);
+	if (ret) {
+		dev_err(dev, "Error: missing \"battery-regulation-voltage\" property\n");
+		return ret;
+	}
+
+	/*
+	 * MIVR and IAICR are optional parameters. Do not return error if one
+	 * of them is not present in ACPI table or device tree specification.
+	 */
+	device_property_read_u32(dev, "richtek,min-input-voltage-regulation",
+				 mivr);
+	device_property_read_u32(dev, "richtek,avg-input-current-regulation",
+				 iaicr);
+
+	ret = rt9455_setup_irq(info);
+	if (ret) {
+		dev_err(dev, "Failed to allocate IRQ resource\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rt9455_usb_event_none(struct rt9455_info *info,
+				 u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_NONE, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_NONE received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_NONE received, therefore IAICR is set to its minimum value\n");
+	if (iaicr != RT9455_IAICR_100MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_100MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_vbus(struct rt9455_info *info,
+				 u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_VBUS, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_VBUS received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_VBUS received, therefore IAICR is set to 500 mA\n");
+	if (iaicr != RT9455_IAICR_500MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_500MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_id(struct rt9455_info *info,
+			       u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_CHARGE_MODE) {
+		/*
+		 * If the charger is in charge mode, and it has received
+		 * USB_EVENT_ID, this means the consumer device powered by the
+		 * charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_ID received, therefore the charger goes into boost mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_BOOST_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in boost mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_ID received, therefore IAICR is set to its minimum value\n");
+	if (iaicr != RT9455_IAICR_100MA) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_100MA);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event_charger(struct rt9455_info *info,
+				    u8 opa_mode, u8 iaicr)
+{
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	if (opa_mode == RT9455_BOOST_MODE) {
+		/*
+		 * If the charger is in boost mode, and it has received
+		 * USB_EVENT_CHARGER, this means the consumer device powered by
+		 * the charger is not connected anymore.
+		 * In this case, the charger goes into charge mode.
+		 */
+		dev_dbg(dev, "USB_EVENT_CHARGER received, therefore the charger goes into charge mode\n");
+		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
+					 RT9455_CHARGE_MODE);
+		if (ret) {
+			dev_err(dev, "Failed to set charger in charge mode\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	dev_dbg(dev, "USB_EVENT_CHARGER received, therefore IAICR is set to no current limit\n");
+	if (iaicr != RT9455_IAICR_NO_LIMIT) {
+		ret = regmap_field_write(info->regmap_fields[F_IAICR],
+					 RT9455_IAICR_NO_LIMIT);
+		if (ret) {
+			dev_err(dev, "Failed to set IAICR value\n");
+			return NOTIFY_DONE;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static int rt9455_usb_event(struct notifier_block *nb,
+			    unsigned long event, void *power)
+{
+	struct rt9455_info *info = container_of(nb, struct rt9455_info, nb);
+	struct device *dev = &info->client->dev;
+	unsigned int opa_mode, iaicr;
+	int ret;
+
+	if (!info)
+		return NOTIFY_DONE;
+
+	/*
+	 * Determine whether the charger is in charge mode
+	 * or in boost mode.
+	 */
+	ret = regmap_field_read(info->regmap_fields[F_OPA_MODE],
+				&opa_mode);
+	if (ret) {
+		dev_err(dev, "Failed to read operation mode value\n");
+		return NOTIFY_DONE;
+	}
+
+	ret = regmap_field_read(info->regmap_fields[F_IAICR],
+				&iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to read IAICR value\n");
+		return NOTIFY_DONE;
+	}
+
+	dev_dbg(dev, "Received USB event %lu\n", event);
+	switch (event) {
+	case USB_EVENT_NONE:
+		return rt9455_usb_event_none(info, opa_mode, iaicr);
+	case USB_EVENT_VBUS:
+		return rt9455_usb_event_vbus(info, opa_mode, iaicr);
+	case USB_EVENT_ID:
+		return rt9455_usb_event_id(info, opa_mode, iaicr);
+	case USB_EVENT_CHARGER:
+		return rt9455_usb_event_charger(info, opa_mode, iaicr);
+	default:
+		dev_err(dev, "Unknown USB event\n");
+	}
+	return NOTIFY_DONE;
+}
+
+static void rt9455_pwr_rdy_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						pwr_rdy_work.work);
+	struct device *dev = &info->client->dev;
+	unsigned int pwr_rdy;
+	int ret;
+
+	ret = regmap_field_read(info->regmap_fields[F_PWR_RDY], &pwr_rdy);
+	if (ret) {
+		dev_err(dev, "Failed to read PWR_RDY bit\n");
+		return;
+	}
+	switch (pwr_rdy) {
+	case RT9455_PWR_FAULT:
+		dev_dbg(dev, "Charger disconnected from power source\n");
+		cancel_delayed_work_sync(&info->max_charging_time_work);
+		break;
+	case RT9455_PWR_GOOD:
+		dev_dbg(dev, "Charger connected to power source\n");
+		ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
+					 RT9455_CHARGE_ENABLE);
+		if (ret) {
+			dev_err(dev, "Failed to enable charging\n");
+			return;
+		}
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->max_charging_time_work,
+				   RT9455_MAX_CHARGING_TIME * HZ);
+		break;
+	}
+}
+
+static void rt9455_max_charging_time_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						max_charging_time_work.work);
+	struct device *dev = &info->client->dev;
+	int ret;
+
+	dev_err(dev, "Battery has been charging for at least 6 hours and is not yet fully charged. Battery is dead, therefore charging is disabled.\n");
+	ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
+				 RT9455_CHARGE_DISABLE);
+	if (ret)
+		dev_err(dev, "Failed to disable charging\n");
+}
+
+static void rt9455_batt_presence_work_callback(struct work_struct *work)
+{
+	struct rt9455_info *info = container_of(work, struct rt9455_info,
+						batt_presence_work.work);
+	struct device *dev = &info->client->dev;
+	unsigned int irq1, mask1;
+	int ret;
+
+	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
+	if (ret) {
+		dev_err(dev, "Failed to read IRQ1 register\n");
+		return;
+	}
+
+	/*
+	 * If the battery is still absent, batt_presence_work is rescheduled.
+	 * Otherwise, max_charging_time is scheduled.
+	 */
+	if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->batt_presence_work,
+				   RT9455_BATT_PRESENCE_DELAY * HZ);
+	} else {
+		queue_delayed_work(system_power_efficient_wq,
+				   &info->max_charging_time_work,
+				   RT9455_MAX_CHARGING_TIME * HZ);
+
+		ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
+		if (ret) {
+			dev_err(dev, "Failed to read MASK1 register\n");
+			return;
+		}
+
+		if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 1) {
+			ret = regmap_field_write(info->regmap_fields[F_BATABM],
+						 0x00);
+			if (ret)
+				dev_err(dev, "Failed to unmask BATAB interrupt\n");
+		}
+	}
+}
+
+static const struct power_supply_desc rt9455_charger_desc = {
+	.name			= RT9455_DRIVER_NAME,
+	.type			= POWER_SUPPLY_TYPE_USB,
+	.properties		= rt9455_charger_properties,
+	.num_properties		= ARRAY_SIZE(rt9455_charger_properties),
+	.get_property		= rt9455_charger_get_property,
+	.set_property		= rt9455_charger_set_property,
+	.property_is_writeable	= rt9455_charger_property_is_writeable,
+};
+
+static int rt9455_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct device *dev = &client->dev;
+	struct rt9455_info *info;
+	struct power_supply_config rt9455_charger_config = {};
+	/* mandatory device-specific data values */
+	u32 ichrg, ieoc_percentage, voreg;
+	/* optional device-specific data values */
+	u32 mivr = -1, iaicr = -1;
+	int i, ret;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
+		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
+		return -ENODEV;
+	}
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->client = client;
+	i2c_set_clientdata(client, info);
+
+	info->regmap = devm_regmap_init_i2c(client,
+					    &rt9455_regmap_config);
+	if (IS_ERR(info->regmap)) {
+		dev_err(dev, "Failed to initialize register map\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		info->regmap_fields[i] =
+			devm_regmap_field_alloc(dev, info->regmap,
+						rt9455_reg_fields[i]);
+		if (IS_ERR(info->regmap_fields[i])) {
+			dev_err(dev,
+				"Failed to allocate regmap field = %d\n", i);
+			return PTR_ERR(info->regmap_fields[i]);
+		}
+	}
+
+	ret = rt9455_discover_charger(info, &ichrg, &ieoc_percentage,
+				      &voreg, &mivr, &iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to discover charger\n");
+		return ret;
+	}
+
+#if IS_ENABLED(CONFIG_USB_PHY)
+	info->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
+	if (IS_ERR_OR_NULL(info->usb_phy)) {
+		dev_err(dev, "Failed to get USB transceiver\n");
+	} else {
+		info->nb.notifier_call = rt9455_usb_event;
+		ret = usb_register_notifier(info->usb_phy, &info->nb);
+		if (ret) {
+			dev_err(dev, "Failed to register USB notifier\n");
+			usb_put_phy(info->usb_phy);
+		}
+	}
+#endif
+
+	INIT_DELAYED_WORK(&info->pwr_rdy_work, rt9455_pwr_rdy_work_callback);
+	INIT_DELAYED_WORK(&info->max_charging_time_work,
+			  rt9455_max_charging_time_work_callback);
+	INIT_DELAYED_WORK(&info->batt_presence_work,
+			  rt9455_batt_presence_work_callback);
+
+	rt9455_charger_config.of_node		= dev->of_node;
+	rt9455_charger_config.drv_data		= info;
+	rt9455_charger_config.supplied_to	= rt9455_charger_supplied_to;
+	rt9455_charger_config.num_supplicants	=
+					ARRAY_SIZE(rt9455_charger_supplied_to);
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					rt9455_irq_handler_thread,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+					RT9455_DRIVER_NAME, info);
+	if (ret < 0) {
+		dev_err(dev, "Failed to register IRQ handler\n");
+		return ret;
+	}
+
+	ret = rt9455_hw_init(info, ichrg, ieoc_percentage, voreg, mivr, iaicr);
+	if (ret) {
+		dev_err(dev, "Failed to set charger to its default values\n");
+		return ret;
+	}
+
+	info->charger = power_supply_register(dev, &rt9455_charger_desc,
+					      &rt9455_charger_config);
+	if (IS_ERR(info->charger)) {
+		dev_err(dev, "Failed to register charger\n");
+		ret = PTR_ERR(info->charger);
+		goto put_usb_phy;
+	}
+
+	return 0;
+
+put_usb_phy:
+#if IS_ENABLED(CONFIG_USB_PHY)
+	if (!IS_ERR_OR_NULL(info->usb_phy))  {
+		usb_unregister_notifier(info->usb_phy, &info->nb);
+		usb_put_phy(info->usb_phy);
+	}
+#endif
+	return ret;
+}
+
+static int rt9455_remove(struct i2c_client *client)
+{
+	int ret;
+	struct rt9455_info *info = i2c_get_clientdata(client);
+
+	ret = rt9455_register_reset(info);
+	if (ret)
+		dev_err(&info->client->dev, "Failed to set charger to its default values\n");
+
+#if IS_ENABLED(CONFIG_USB_PHY)
+	if (!IS_ERR_OR_NULL(info->usb_phy)) {
+		usb_unregister_notifier(info->usb_phy, &info->nb);
+		usb_put_phy(info->usb_phy);
+	}
+#endif
+
+	cancel_delayed_work_sync(&info->pwr_rdy_work);
+	cancel_delayed_work_sync(&info->max_charging_time_work);
+	cancel_delayed_work_sync(&info->batt_presence_work);
+
+	power_supply_unregister(info->charger);
+
+	return ret;
+}
+
+static const struct i2c_device_id rt9455_i2c_id_table[] = {
+	{ RT9455_DRIVER_NAME, 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, rt9455_i2c_id_table);
+
+static const struct of_device_id rt9455_of_match[] = {
+	{ .compatible = "richtek,rt9455", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rt9455_of_match);
+
+static const struct acpi_device_id rt9455_i2c_acpi_match[] = {
+	{ "RT945500", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, rt9455_i2c_acpi_match);
+
+static struct i2c_driver rt9455_driver = {
+	.probe		= rt9455_probe,
+	.remove		= rt9455_remove,
+	.id_table	= rt9455_i2c_id_table,
+	.driver = {
+		.name		= RT9455_DRIVER_NAME,
+		.of_match_table	= of_match_ptr(rt9455_of_match),
+		.acpi_match_table = ACPI_PTR(rt9455_i2c_acpi_match),
+	},
+};
+module_i2c_driver(rt9455_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anda-Maria Nicolae <anda-maria.nicolae-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>");
+MODULE_ALIAS("i2c:rt9455-charger");
+MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
-- 
1.7.9.5

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^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-04-29 20:13 ` Anda-Maria Nicolae
  (?)
@ 2015-04-30  7:53 ` Krzysztof Kozlowski
  2015-05-04 12:48   ` Nicolae, Anda-maria
  -1 siblings, 1 reply; 8+ messages in thread
From: Krzysztof Kozlowski @ 2015-04-30  7:53 UTC (permalink / raw)
  To: Anda-Maria Nicolae
  Cc: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

2015-04-30 5:13 GMT+09:00 Anda-Maria Nicolae <anda-maria.nicolae@intel.com>:
> Based on the datasheet found here:
> http://www.richtek.com/download_ds.jsp?p=RT9455
>
> Updates from the previous version:
> - replaced license GPLv2 with GPL
> - replaced vendor prefix rt with richtek
> - replaced uppercase properties names from devicetree with lowercase separated by dash properties names
> - replaced I/O read/write API with regmap_read/write and regmap_field_read/write
> - used kernel multiline comment
> - used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.

I think when device is suspended (e.g. to RAM) no work will ever be
executed. The timers (for delayed work) will not wake up the device...
RTC could wake but this is different story. My proposal of deferred
timers is affected by idle CPU time. Are you sure that you want to
wake up from the system suspend?

> - replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc
> - replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
> - replaced {"RTK9455", 0} with { "RTK9455", 0 }
> - removed .owner = THIS_MODULE
>
> Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>

You missed some of my comments. I mentioned wrong error paths around
put_usb_phy in probe. They do not seem to be fixed...

Just one hint - mostly new bindings are posted in separate patches at
the beginning of the patchset. I actually don't mind. but separating
them will probably give you higher chance of review from DT people.
This is also mentioned in:
Documentation/devicetree/bindings/submitting-patches.txt

Best regards,
Krzysztof

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-04-29 20:13 ` Anda-Maria Nicolae
  (?)
  (?)
@ 2015-04-30  9:16 ` Laurentiu Palcu
  2015-05-04 14:12   ` Nicolae, Anda-maria
  -1 siblings, 1 reply; 8+ messages in thread
From: Laurentiu Palcu @ 2015-04-30  9:16 UTC (permalink / raw)
  To: Anda-Maria Nicolae
  Cc: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

More comments inline.

laurentiu

On Wed, Apr 29, 2015 at 11:13:26PM +0300, Anda-Maria Nicolae wrote:
> Based on the datasheet found here:
> http://www.richtek.com/download_ds.jsp?p=RT9455
> 
> Updates from the previous version:
> - replaced license GPLv2 with GPL
> - replaced vendor prefix rt with richtek
> - replaced uppercase properties names from devicetree with lowercase separated by dash properties names
> - replaced I/O read/write API with regmap_read/write and regmap_field_read/write
> - used kernel multiline comment
> - used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.
> - replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc 
> - replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
> - replaced {"RTK9455", 0} with { "RTK9455", 0 }
> - removed .owner = THIS_MODULE
The change log should go after '---'.  Otherwise it will end up in the
commit message.

> 
> Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
> ---
>  .../devicetree/bindings/power/rt9455_charger.txt   |   43 +
>  .../devicetree/bindings/vendor-prefixes.txt        |    1 +
>  drivers/power/Kconfig                              |    6 +
>  drivers/power/Makefile                             |    1 +
>  drivers/power/rt9455_charger.c                     | 1758 ++++++++++++++++++++
>  5 files changed, 1809 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/rt9455_charger.txt
>  create mode 100644 drivers/power/rt9455_charger.c
(...)

> 
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 4091fb0..39f208d 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -439,6 +439,12 @@ config BATTERY_RT5033
>  	  The fuelgauge calculates and determines the battery state of charge
>  	  according to battery open circuit voltage.
>  
> +config CHARGER_RT9455
> +	tristate "Richtek RT9455 battery charger driver"
> +	depends on I2C && GPIOLIBa
depends on REGMAP_I2C

> +	help
> +	Say Y to enable support for the Richtek RT9455 battery charger.
> +
>  source "drivers/power/reset/Kconfig"
>  
>  endif # POWER_SUPPLY
(...)

> diff --git a/drivers/power/rt9455_charger.c b/drivers/power/rt9455_charger.c
> new file mode 100644
> index 0000000..e45b0f2
> --- /dev/null
> +++ b/drivers/power/rt9455_charger.c
> @@ -0,0 +1,1758 @@
> +/*
> + * Driver for Richtek RT9455WSC battery charger.
> + *
> + * Copyright (C) 2015 Intel Corporation
> + *
> + * 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/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/power_supply.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/acpi.h>
> +#include <linux/usb/phy.h>
> +#include <linux/regmap.h>
> +
> +#define RT9455_MANUFACTURER			"Richtek"
> +#define RT9455_MODEL_NAME			"RT9455"
> +#define RT9455_DRIVER_NAME			"rt9455-charger"
> +
> +#define RT9455_IRQ_NAME				"interrupt"
> +
> +#define RT9455_PWR_RDY_DELAY			1 /* 1 second */
> +#define RT9455_MAX_CHARGING_TIME		21600 /* 6 hrs */
> +#define RT9455_BATT_PRESENCE_DELAY		60 /* 60 seconds */
> +
> +#define RT9455_CHARGE_MODE			0x00
> +#define RT9455_BOOST_MODE			0x01
> +
> +#define RT9455_FAULT				0x03
> +
> +#define RT9455_IAICR_100MA			0x00
> +#define RT9455_IAICR_500MA			0x01
> +#define RT9455_IAICR_NO_LIMIT			0x03
> +
> +#define RT9455_CHARGE_DISABLE			0x00
> +#define RT9455_CHARGE_ENABLE			0x01
> +
> +#define RT9455_PWR_FAULT			0x00
> +#define RT9455_PWR_GOOD				0x01
> +
> +#define RT9455_REG_CTRL1			0x00 /* CTRL1 reg address */
> +#define RT9455_REG_CTRL1_STAT_MASK		(BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL1_BOOST_MASK		BIT(3)
> +#define RT9455_REG_CTRL1_PWR_RDY_MASK		BIT(2)
> +#define RT9455_REG_CTRL1_OTG_PIN_POLARITY_MASK	BIT(1)
Since you're using regmap fields, you can get rid of the masks above.
The same applies for the masks below (except those for the IRQ
registers which you seem to use).

> +
> +#define RT9455_REG_CTRL2			0x01 /* CTRL2 reg address */
> +#define RT9455_REG_CTRL2_IAICR_MASK		(BIT(7) | BIT(6))
> +#define RT9455_REG_CTRL2_TE_SHDN_EN_MASK	BIT(5)
> +#define RT9455_REG_CTRL2_HIGHER_OCP_MASK	BIT(4)
> +#define RT9455_REG_CTRL2_TE_MASK		BIT(3)
> +#define RT9455_REG_CTRL2_IAICR_INT_MASK		BIT(2)
> +#define RT9455_REG_CTRL2_HIZ_MASK		BIT(1)
> +#define RT9455_REG_CTRL2_OPA_MODE_MASK		BIT(0)
> +
> +#define RT9455_REG_CTRL3			0x02 /* CTRL3 reg address */
> +#define RT9455_REG_CTRL3_VOREG_MASK		(BIT(7) | BIT(6) | BIT(5) | \
> +						 BIT(4) | BIT(3) | BIT(2))
> +#define RT9455_REG_CTRL3_OTG_PL_MASK		BIT(1)
> +#define RT9455_REG_CTRL3_OTG_EN_MASK		BIT(0)
> +
> +#define RT9455_REG_DEV_ID			0x03 /* DEV_ID reg address */
> +#define RT9455_REG_DEV_ID_VENDOR_ID_MASK	(BIT(7) | BIT(6) | BIT(5) | \
> +						 BIT(4))
> +#define RT9455_REG_DEV_ID_CHIP_REV_MASK		(BIT(3) | BIT(2) | BIT(1) | \
> +						 BIT(0))
> +
> +#define RT9455_REG_CTRL4			0x04 /* CTRL4 reg address */
> +#define RT9455_REG_CTRL4_RST_MASK		BIT(7)
> +
> +#define RT9455_REG_CTRL5			0x05 /* CTRL5 reg address */
> +#define RT9455_REG_CTRL5_TMR_EN_MASK		BIT(7)
> +#define RT9455_REG_CTRL5_MIVR_MASK		(BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL5_IPREC_MASK		(BIT(3) | BIT(2))
> +#define RT9455_REG_CTRL5_IEOC_PERCENTAGE_MASK	(BIT(1) | BIT(0))
> +
> +#define RT9455_REG_CTRL6			0x06 /* CTRL6 reg address */
> +#define RT9455_REG_CTRL6_IAICR_SEL_MASK		BIT(7)
> +#define RT9455_REG_CTRL6_ICHRG_MASK		(BIT(6) | BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL6_VPREC_MASK		(BIT(2) | BIT(1) | BIT(0))
> +
> +#define RT9455_REG_CTRL7			0x07 /* CTRL7 reg address */
> +#define RT9455_REG_CTRL7_BATD_EN_MASK		BIT(6)
> +#define RT9455_REG_CTRL7_CHG_EN_MASK		BIT(4)
> +#define RT9455_REG_CTRL7_VMREG_MASK		(BIT(3) | BIT(2) | BIT(1) | \
> +						 BIT(0))
> +
> +#define RT9455_REG_IRQ1				0x08 /* IRQ1 reg address */
> +#define RT9455_REG_IRQ1_TSDI_MASK		BIT(7)
> +#define RT9455_REG_IRQ1_VINOVPI_MASK		BIT(6)
> +#define RT9455_REG_IRQ1_BATAB_MASK		BIT(0)
> +
> +#define RT9455_REG_IRQ2				0x09 /* IRQ2 reg address */
> +#define RT9455_REG_IRQ2_CHRVPI_MASK		BIT(7)
> +#define RT9455_REG_IRQ2_CHBATOVI_MASK		BIT(5)
> +#define RT9455_REG_IRQ2_CHTERMI_MASK		BIT(4)
> +#define RT9455_REG_IRQ2_CHRCHGI_MASK		BIT(3)
> +#define RT9455_REG_IRQ2_CH32MI_MASK		BIT(2)
> +#define RT9455_REG_IRQ2_CHTREGI_MASK		BIT(1)
> +#define RT9455_REG_IRQ2_CHMIVRI_MASK		BIT(0)
> +
> +#define RT9455_REG_IRQ3				0x0A /* IRQ3 reg address */
> +#define RT9455_REG_IRQ3_BSTBUSOVI_MASK		BIT(7)
> +#define RT9455_REG_IRQ3_BSTOLI_MASK		BIT(6)
> +#define RT9455_REG_IRQ3_BSTLOWVI_MASK		BIT(5)
> +#define RT9455_REG_IRQ3_BST32SI_MASK		BIT(3)
> +
> +#define RT9455_REG_MASK1			0x0B /* MASK1 reg address */
> +#define RT9455_REG_MASK1_TSDM_MASK		BIT(7)
> +#define RT9455_REG_MASK1_VINOVPIM_MASK		BIT(6)
> +#define RT9455_REG_MASK1_BATABM_MASK		BIT(0)
> +
> +#define RT9455_REG_MASK2			0x0C /* MASK2 reg address */
> +#define RT9455_REG_MASK2_CHRVPIM_MASK		BIT(7)
> +#define RT9455_REG_MASK2_CHBATOVIM_MASK		BIT(5)
> +#define RT9455_REG_MASK2_CHTERMIM_MASK		BIT(4)
> +#define RT9455_REG_MASK2_CHRCHGIM_MASK		BIT(3)
> +#define RT9455_REG_MASK2_CH32MIM_MASK		BIT(2)
> +#define RT9455_REG_MASK2_CHTREGIM_MASK		BIT(1)
> +#define RT9455_REG_MASK2_CHMIVRIM_MASK		BIT(0)
> +
> +#define RT9455_REG_MASK3			0x0D /* MASK3 reg address */
> +#define RT9455_REG_MASK3_BSTVINOVIM_MASK	BIT(7)
> +#define RT9455_REG_MASK3_BSTOLIM_MASK		BIT(6)
> +#define RT9455_REG_MASK3_BSTLOWVIM_MASK		BIT(5)
> +#define RT9455_REG_MASK3_BST32SIM_MASK		BIT(3)
> +
> +enum rt9455_fields {
> +	F_STAT, F_BOOST, F_PWR_RDY, F_OTG_PIN_POLARITY, /* CTRL1 reg fields */
> +
> +	F_IAICR, F_TE_SHDN_EN, F_HIGHER_OCP, F_TE, F_IAICR_INT, F_HIZ,
> +	F_OPA_MODE, /* CTRL2 reg fields */
> +
> +	F_VOREG, F_OTG_PL, F_OTG_EN, /* CTRL3 reg fields */
> +
> +	F_VENDOR_ID, F_CHIP_REV, /* DEV_ID reg fields */
> +
> +	F_RST, /* CTRL4 reg fields */
> +
> +	F_TMR_EN, F_MIVR, F_IPREC, F_IEOC_PERCENTAGE, /* CTRL5 reg fields*/
> +
> +	F_IAICR_SEL, F_ICHRG, F_VPREC, /* CTRL6 reg fields */
> +
> +	F_BATD_EN, F_CHG_EN, F_VMREG, /* CTRL7 reg fields */
> +
> +	F_TSDI, F_VINOVPI, F_BATAB, /* IRQ1 reg fields */
> +
> +	F_CHRVPI, F_CHBATOVI, F_CHTERMI, F_CHRCHGI, F_CH32MI, F_CHTREGI,
> +	F_CHMIVRI, /* IRQ2 reg fields */
> +
> +	F_BSTBUSOVI, F_BSTOLI, F_BSTLOWVI, F_BST32SI, /* IRQ3 reg fields */
> +
> +	F_TSDM, F_VINOVPIM, F_BATABM, /* MASK1 reg fields */
> +
> +	F_CHRVPIM, F_CHBATOVIM, F_CHTERMIM, F_CHRCHGIM, F_CH32MIM, F_CHTREGIM,
> +	F_CHMIVRIM, /* MASK2 reg fields */
> +
> +	F_BSTVINOVIM, F_BSTOLIM, F_BSTLOWVIM, F_BST32SIM, /* MASK3 reg fields */
> +
> +	F_MAX_FIELDS
> +};
> +
> +static const struct reg_field rt9455_reg_fields[] = {
> +	[F_STAT]		= REG_FIELD(RT9455_REG_CTRL1, 4, 5),
> +	[F_BOOST]		= REG_FIELD(RT9455_REG_CTRL1, 3, 3),
> +	[F_PWR_RDY]		= REG_FIELD(RT9455_REG_CTRL1, 2, 2),
> +	[F_OTG_PIN_POLARITY]	= REG_FIELD(RT9455_REG_CTRL1, 1, 1),
> +
> +	[F_IAICR]		= REG_FIELD(RT9455_REG_CTRL2, 6, 7),
> +	[F_TE_SHDN_EN]		= REG_FIELD(RT9455_REG_CTRL2, 5, 5),
> +	[F_HIGHER_OCP]		= REG_FIELD(RT9455_REG_CTRL2, 4, 4),
> +	[F_TE]			= REG_FIELD(RT9455_REG_CTRL2, 3, 3),
> +	[F_IAICR_INT]		= REG_FIELD(RT9455_REG_CTRL2, 2, 2),
> +	[F_HIZ]			= REG_FIELD(RT9455_REG_CTRL2, 1, 1),
> +	[F_OPA_MODE]		= REG_FIELD(RT9455_REG_CTRL2, 0, 0),
> +
> +	[F_VOREG]		= REG_FIELD(RT9455_REG_CTRL3, 2, 7),
> +	[F_OTG_PL]		= REG_FIELD(RT9455_REG_CTRL3, 1, 1),
> +	[F_OTG_EN]		= REG_FIELD(RT9455_REG_CTRL3, 0, 0),
> +
> +	[F_VENDOR_ID]		= REG_FIELD(RT9455_REG_DEV_ID, 4, 7),
> +	[F_CHIP_REV]		= REG_FIELD(RT9455_REG_DEV_ID, 0, 3),
> +
> +	[F_RST]			= REG_FIELD(RT9455_REG_CTRL4, 7, 7),
> +
> +	[F_TMR_EN]		= REG_FIELD(RT9455_REG_CTRL5, 7, 7),
> +	[F_MIVR]		= REG_FIELD(RT9455_REG_CTRL5, 4, 5),
> +	[F_IPREC]		= REG_FIELD(RT9455_REG_CTRL5, 2, 3),
> +	[F_IEOC_PERCENTAGE]	= REG_FIELD(RT9455_REG_CTRL5, 0, 1),
> +
> +	[F_IAICR_SEL]		= REG_FIELD(RT9455_REG_CTRL6, 7, 7),
> +	[F_ICHRG]		= REG_FIELD(RT9455_REG_CTRL6, 4, 6),
> +	[F_VPREC]		= REG_FIELD(RT9455_REG_CTRL6, 0, 2),
> +
> +	[F_BATD_EN]		= REG_FIELD(RT9455_REG_CTRL7, 6, 6),
> +	[F_CHG_EN]		= REG_FIELD(RT9455_REG_CTRL7, 4, 4),
> +	[F_VMREG]		= REG_FIELD(RT9455_REG_CTRL7, 0, 3),
> +
> +	[F_TSDI]		= REG_FIELD(RT9455_REG_IRQ1, 7, 7),
> +	[F_VINOVPI]		= REG_FIELD(RT9455_REG_IRQ1, 6, 6),
> +	[F_BATAB]		= REG_FIELD(RT9455_REG_IRQ1, 0, 0),
> +
> +	[F_CHRVPI]		= REG_FIELD(RT9455_REG_IRQ2, 7, 7),
> +	[F_CHBATOVI]		= REG_FIELD(RT9455_REG_IRQ2, 5, 5),
> +	[F_CHTERMI]		= REG_FIELD(RT9455_REG_IRQ2, 4, 4),
> +	[F_CHRCHGI]		= REG_FIELD(RT9455_REG_IRQ2, 3, 3),
> +	[F_CH32MI]		= REG_FIELD(RT9455_REG_IRQ2, 2, 2),
> +	[F_CHTREGI]		= REG_FIELD(RT9455_REG_IRQ2, 1, 1),
> +	[F_CHMIVRI]		= REG_FIELD(RT9455_REG_IRQ2, 0, 0),
> +
> +	[F_BSTBUSOVI]		= REG_FIELD(RT9455_REG_IRQ3, 7, 7),
> +	[F_BSTOLI]		= REG_FIELD(RT9455_REG_IRQ3, 6, 6),
> +	[F_BSTLOWVI]		= REG_FIELD(RT9455_REG_IRQ3, 5, 5),
> +	[F_BST32SI]		= REG_FIELD(RT9455_REG_IRQ3, 3, 3),
I don't see any benefit in declaring fields for the IRQx registers, since
you're not going to use them. AFAICS you're reading the entire IRQx
registers and then use masks to retrieve the fields.
> +
> +	[F_TSDM]		= REG_FIELD(RT9455_REG_MASK1, 7, 7),
> +	[F_VINOVPIM]		= REG_FIELD(RT9455_REG_MASK1, 6, 6),
> +	[F_BATABM]		= REG_FIELD(RT9455_REG_MASK1, 0, 0),
> +
> +	[F_CHRVPIM]		= REG_FIELD(RT9455_REG_MASK2, 7, 7),
> +	[F_CHBATOVIM]		= REG_FIELD(RT9455_REG_MASK2, 5, 5),
> +	[F_CHTERMIM]		= REG_FIELD(RT9455_REG_MASK2, 4, 4),
> +	[F_CHRCHGIM]		= REG_FIELD(RT9455_REG_MASK2, 3, 3),
> +	[F_CH32MIM]		= REG_FIELD(RT9455_REG_MASK2, 2, 2),
> +	[F_CHTREGIM]		= REG_FIELD(RT9455_REG_MASK2, 1, 1),
> +	[F_CHMIVRIM]		= REG_FIELD(RT9455_REG_MASK2, 0, 0),
> +
> +	[F_BSTVINOVIM]		= REG_FIELD(RT9455_REG_MASK3, 7, 7),
> +	[F_BSTOLIM]		= REG_FIELD(RT9455_REG_MASK3, 6, 6),
> +	[F_BSTLOWVIM]		= REG_FIELD(RT9455_REG_MASK3, 5, 5),
> +	[F_BST32SIM]		= REG_FIELD(RT9455_REG_MASK3, 3, 3),
> +};
> +
> +/*
> + * Each array initialised below shows the possible real-world values for a
> + * group of bits belonging to RT9455 registers. The arrays are sorted in
> + * ascending order. The index of each real-world value represents the value
> + * that is encoded in the group of bits belonging to RT9455 registers.
> + */
> +/* REG06[6:4] (ICHRG) in uAh */
> +static const int rt9455_ichrg_values[] = {
> +	 500000,  650000,  800000,  950000, 1100000, 1250000, 1400000, 1550000
> +};
> +
> +/* REG02[7:2] (VOREG) in uV */
> +static const int rt9455_voreg_values[] = {
> +	3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
> +	3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
> +	3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
> +	3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
> +	4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
> +	4300000, 4330000, 4350000, 4370000, 4390000, 4410000, 4430000, 4450000,
> +	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000,
> +	4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000
> +};
> +
> +/* REG07[3:0] (VMREG) in uV */
> +static const int rt9455_vmreg_values[] = {
> +	4200000, 4220000, 4240000, 4260000, 4280000, 4300000, 4320000, 4340000,
> +	4360000, 4380000, 4400000, 4430000, 4450000, 4450000, 4450000, 4450000
> +};
> +
> +/* REG05[5:4] (IEOC_PERCENTAGE) */
> +static const int rt9455_ieoc_percentage_values[] = {
> +	10, 30, 20, 30
> +};
> +
> +/* REG05[1:0] (MIVR) in uV */
> +static const int rt9455_mivr_values[] = {
> +	4000000, 4250000, 4500000, 5000000
> +};
> +
> +/* REG05[1:0] (IAICR) in uA */
> +static const int rt9455_iaicr_values[] = {
> +	100000, 500000, 1000000, 2000000
> +};
> +
> +struct rt9455_info {
> +	struct i2c_client		*client;
> +	struct regmap			*regmap;
> +	struct regmap_field		*regmap_fields[F_MAX_FIELDS];
> +	struct power_supply		*charger;
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +	struct usb_phy			*usb_phy;
> +	struct notifier_block		nb;
> +#endif
> +	struct gpio_desc		*gpiod_irq;
> +	unsigned int			gpio_irq;
> +	struct delayed_work		pwr_rdy_work;
> +	struct delayed_work		max_charging_time_work;
> +	struct delayed_work		batt_presence_work;
> +};
> +
> +static const struct regmap_config rt9455_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = RT9455_REG_MASK3,
> +};
Do you need all chip's registers to be volatile? Can we cache any of
them so we don't make unnecessary read operations on the I2C bus?

(...)
> +
> +static int rt9455_charger_get_status(struct rt9455_info *info,
> +				     union power_supply_propval *val)
> +{
> +	unsigned int v;
> +	int ret;
> +
> +	ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
> +	if (ret) {
> +		dev_err(&info->client->dev, "Failed to read STAT bits\n");
> +		return ret;
> +	}
> +
> +	switch (v) {
> +	case 0:
> +		val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +	break;
> +	case 1:
> +		val->intval = POWER_SUPPLY_STATUS_CHARGING;
> +	break;
> +	case 2:
> +		val->intval = POWER_SUPPLY_STATUS_FULL;
> +	break;
> +	default:
> +		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
> +	break;
> +	}
Please indent the breaks to conform to kernel coding style.

Also, just an idea, maybe you should also return
POWER_SUPPLY_STATUS_DISCHARGING when the power is not plugged in
because, technically, if PWR_RDY=0 the battery will discharge...

(...)

> +
> +static int rt9455_charger_get_voltage_max(struct rt9455_info *info,
> +					  union power_supply_propval *val)
> +{
> +	int idx = ARRAY_SIZE(rt9455_voreg_values) - 1;
rt9455_vmreg_values?

> +
> +	val->intval = rt9455_voreg_values[idx];
ditto.

> +
> +	return 0;
> +}
(...)
> +
> +static int rt9455_charger_get_property(struct power_supply *psy,
> +				       enum power_supply_property psp,
> +				       union power_supply_propval *val)
> +{
> +	struct rt9455_info *info = power_supply_get_drvdata(psy);
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_STATUS:
> +		return rt9455_charger_get_status(info, val);
> +	case POWER_SUPPLY_PROP_HEALTH:
> +		return rt9455_charger_get_health(info, val);
> +	case POWER_SUPPLY_PROP_PRESENT:
> +		return rt9455_charger_get_battery_presence(info, val);
> +	case POWER_SUPPLY_PROP_ONLINE:
> +		return rt9455_charger_get_online(info, val);
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +		return rt9455_charger_get_current(info, val);
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
> +		return rt9455_charger_get_current_max(info, val);
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> +		return rt9455_charger_get_voltage(info, val);
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> +		return rt9455_charger_get_voltage_max(info, val);
> +	case POWER_SUPPLY_PROP_SCOPE:
> +		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
> +		return 0;
> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
> +		return rt9455_charger_get_term_current(info, val);
> +	case POWER_SUPPLY_PROP_MODEL_NAME:
> +		val->strval = RT9455_MODEL_NAME;
> +		return 0;
> +	case POWER_SUPPLY_PROP_MANUFACTURER:
> +		val->strval = RT9455_MANUFACTURER;
> +		return 0;
> +	default:
> +		return -ENODATA;
> +	}
> +}
> +
(...)
> +
> +static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
> +					  const union power_supply_propval *val)
> +{
> +	return rt9455_set_field_val(info, F_VMREG,
> +				    rt9455_vmreg_values,
> +				    ARRAY_SIZE(rt9455_vmreg_values),
> +				    val->intval);
> +}
> +
> +static int rt9455_charger_set_property(struct power_supply *psy,
> +				       enum power_supply_property psp,
> +				       const union power_supply_propval *val)
> +{
> +	struct rt9455_info *info = power_supply_get_drvdata(psy);
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +		return rt9455_charger_set_current(info, val);
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> +		return rt9455_charger_set_voltage(info, val);
Personally, I'm against having these properties writable. A user might
play with the charging voltage or current and then complain that the
battery does not charge at all, or it takes ages to charge. I'd leave
these to be set by manufacturer through DT/ACPI. But, it's just an
opinion.

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> +		return rt9455_charger_set_voltage_max(info, val);
You set the max voltage here, but rt9455_charger_get_voltage_max()
returns the maximum allowed value. Shouldn't it return the value you
just set here?

> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
(...)

> +
> +static int rt9455_usb_event_none(struct rt9455_info *info,
> +				 u8 opa_mode, u8 iaicr)
> +{
> +	struct device *dev = &info->client->dev;
> +	int ret;
> +
> +	if (opa_mode == RT9455_BOOST_MODE) {
> +		/*
> +		 * If the charger is in boost mode, and it has received
> +		 * USB_EVENT_NONE, this means the consumer device powered by the
> +		 * charger is not connected anymore.
> +		 * In this case, the charger goes into charge mode.
> +		 */
> +		dev_dbg(dev, "USB_EVENT_NONE received, therefore the charger goes into charge mode\n");
Do you really need both the comment and the dev_dbg? The latter seems
explanatory enough, even though I'd shorten it a little: "USB_EVENT_NONE
received, enter charge mode". The same goes for the next 4 functions.

> +		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +					 RT9455_CHARGE_MODE);
> +		if (ret) {
> +			dev_err(dev, "Failed to set charger in charge mode\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	dev_dbg(dev, "USB_EVENT_NONE received, therefore IAICR is set to its minimum value\n");
> +	if (iaicr != RT9455_IAICR_100MA) {
> +		ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +					 RT9455_IAICR_100MA);
> +		if (ret) {
> +			dev_err(dev, "Failed to set IAICR value\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_vbus(struct rt9455_info *info,
> +				 u8 opa_mode, u8 iaicr)
> +{
> +	struct device *dev = &info->client->dev;
> +	int ret;
> +
> +	if (opa_mode == RT9455_BOOST_MODE) {
> +		/*
> +		 * If the charger is in boost mode, and it has received
> +		 * USB_EVENT_VBUS, this means the consumer device powered by the
> +		 * charger is not connected anymore.
> +		 * In this case, the charger goes into charge mode.
> +		 */
> +		dev_dbg(dev, "USB_EVENT_VBUS received, therefore the charger goes into charge mode\n");
> +		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +					 RT9455_CHARGE_MODE);
> +		if (ret) {
> +			dev_err(dev, "Failed to set charger in charge mode\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	dev_dbg(dev, "USB_EVENT_VBUS received, therefore IAICR is set to 500 mA\n");
> +	if (iaicr != RT9455_IAICR_500MA) {
> +		ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +					 RT9455_IAICR_500MA);
> +		if (ret) {
> +			dev_err(dev, "Failed to set IAICR value\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_id(struct rt9455_info *info,
> +			       u8 opa_mode, u8 iaicr)
> +{
> +	struct device *dev = &info->client->dev;
> +	int ret;
> +
> +	if (opa_mode == RT9455_CHARGE_MODE) {
> +		/*
> +		 * If the charger is in charge mode, and it has received
> +		 * USB_EVENT_ID, this means the consumer device powered by the
> +		 * charger is not connected anymore.
> +		 * In this case, the charger goes into charge mode.
s/goes into charge mode/goes into boost mode/

> +		 */
> +		dev_dbg(dev, "USB_EVENT_ID received, therefore the charger goes into boost mode\n");
> +		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +					 RT9455_BOOST_MODE);
> +		if (ret) {
> +			dev_err(dev, "Failed to set charger in boost mode\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	dev_dbg(dev, "USB_EVENT_ID received, therefore IAICR is set to its minimum value\n");
> +	if (iaicr != RT9455_IAICR_100MA) {
> +		ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +					 RT9455_IAICR_100MA);
> +		if (ret) {
> +			dev_err(dev, "Failed to set IAICR value\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_charger(struct rt9455_info *info,
> +				    u8 opa_mode, u8 iaicr)
> +{
> +	struct device *dev = &info->client->dev;
> +	int ret;
> +
> +	if (opa_mode == RT9455_BOOST_MODE) {
> +		/*
> +		 * If the charger is in boost mode, and it has received
> +		 * USB_EVENT_CHARGER, this means the consumer device powered by
> +		 * the charger is not connected anymore.
> +		 * In this case, the charger goes into charge mode.
> +		 */
> +		dev_dbg(dev, "USB_EVENT_CHARGER received, therefore the charger goes into charge mode\n");
> +		ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +					 RT9455_CHARGE_MODE);
> +		if (ret) {
> +			dev_err(dev, "Failed to set charger in charge mode\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	dev_dbg(dev, "USB_EVENT_CHARGER received, therefore IAICR is set to no current limit\n");
> +	if (iaicr != RT9455_IAICR_NO_LIMIT) {
> +		ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +					 RT9455_IAICR_NO_LIMIT);
> +		if (ret) {
> +			dev_err(dev, "Failed to set IAICR value\n");
> +			return NOTIFY_DONE;
> +		}
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
(...)
> +
> +static void rt9455_max_charging_time_work_callback(struct work_struct *work)
> +{
> +	struct rt9455_info *info = container_of(work, struct rt9455_info,
> +						max_charging_time_work.work);
> +	struct device *dev = &info->client->dev;
> +	int ret;
> +
> +	dev_err(dev, "Battery has been charging for at least 6 hours and is not yet fully charged. Battery is dead, therefore charging is disabled.\n");
If battery is not charged in 6 hours may not necessarily mean that it's
dead... Perhaps a low charge current was set. So, why not shorten this
to just: "Safety timer expired, disable charging."

> +	ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
> +				 RT9455_CHARGE_DISABLE);
> +	if (ret)
> +		dev_err(dev, "Failed to disable charging\n");
> +}
> +
> +static void rt9455_batt_presence_work_callback(struct work_struct *work)
> +{
> +	struct rt9455_info *info = container_of(work, struct rt9455_info,
> +						batt_presence_work.work);
> +	struct device *dev = &info->client->dev;
> +	unsigned int irq1, mask1;
> +	int ret;
> +
> +	ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
> +	if (ret) {
> +		dev_err(dev, "Failed to read IRQ1 register\n");
> +		return;
> +	}
> +
> +	/*
> +	 * If the battery is still absent, batt_presence_work is rescheduled.
> +	 * Otherwise, max_charging_time is scheduled.
> +	 */
> +	if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
> +		queue_delayed_work(system_power_efficient_wq,
> +				   &info->batt_presence_work,
> +				   RT9455_BATT_PRESENCE_DELAY * HZ);
> +	} else {
> +		queue_delayed_work(system_power_efficient_wq,
> +				   &info->max_charging_time_work,
> +				   RT9455_MAX_CHARGING_TIME * HZ);
> +
> +		ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
> +		if (ret) {
> +			dev_err(dev, "Failed to read MASK1 register\n");
> +			return;
> +		}
> +
> +		if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 1) {
> +			ret = regmap_field_write(info->regmap_fields[F_BATABM],
> +						 0x00);
> +			if (ret)
> +				dev_err(dev, "Failed to unmask BATAB interrupt\n");
> +		}
> +	}
> +}
> +
> +static const struct power_supply_desc rt9455_charger_desc = {
> +	.name			= RT9455_DRIVER_NAME,
> +	.type			= POWER_SUPPLY_TYPE_USB,
> +	.properties		= rt9455_charger_properties,
> +	.num_properties		= ARRAY_SIZE(rt9455_charger_properties),
> +	.get_property		= rt9455_charger_get_property,
> +	.set_property		= rt9455_charger_set_property,
> +	.property_is_writeable	= rt9455_charger_property_is_writeable,
> +};
> +
> +static int rt9455_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> +	struct device *dev = &client->dev;
> +	struct rt9455_info *info;
> +	struct power_supply_config rt9455_charger_config = {};
> +	/* mandatory device-specific data values */
> +	u32 ichrg, ieoc_percentage, voreg;
> +	/* optional device-specific data values */
> +	u32 mivr = -1, iaicr = -1;
> +	int i, ret;
> +
> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
> +		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
> +		return -ENODEV;
> +	}
> +	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	info->client = client;
> +	i2c_set_clientdata(client, info);
> +
> +	info->regmap = devm_regmap_init_i2c(client,
> +					    &rt9455_regmap_config);
> +	if (IS_ERR(info->regmap)) {
> +		dev_err(dev, "Failed to initialize register map\n");
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < F_MAX_FIELDS; i++) {
> +		info->regmap_fields[i] =
> +			devm_regmap_field_alloc(dev, info->regmap,
> +						rt9455_reg_fields[i]);
> +		if (IS_ERR(info->regmap_fields[i])) {
> +			dev_err(dev,
> +				"Failed to allocate regmap field = %d\n", i);
> +			return PTR_ERR(info->regmap_fields[i]);
> +		}
> +	}
> +
> +	ret = rt9455_discover_charger(info, &ichrg, &ieoc_percentage,
> +				      &voreg, &mivr, &iaicr);
> +	if (ret) {
> +		dev_err(dev, "Failed to discover charger\n");
> +		return ret;
> +	}
> +
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +	info->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
> +	if (IS_ERR_OR_NULL(info->usb_phy)) {
> +		dev_err(dev, "Failed to get USB transceiver\n");
> +	} else {
> +		info->nb.notifier_call = rt9455_usb_event;
> +		ret = usb_register_notifier(info->usb_phy, &info->nb);
> +		if (ret) {
> +			dev_err(dev, "Failed to register USB notifier\n");
> +			usb_put_phy(info->usb_phy);
> +		}
> +	}
> +#endif
> +
> +	INIT_DELAYED_WORK(&info->pwr_rdy_work, rt9455_pwr_rdy_work_callback);
> +	INIT_DELAYED_WORK(&info->max_charging_time_work,
> +			  rt9455_max_charging_time_work_callback);
> +	INIT_DELAYED_WORK(&info->batt_presence_work,
> +			  rt9455_batt_presence_work_callback);
> +
> +	rt9455_charger_config.of_node		= dev->of_node;
> +	rt9455_charger_config.drv_data		= info;
> +	rt9455_charger_config.supplied_to	= rt9455_charger_supplied_to;
> +	rt9455_charger_config.num_supplicants	=
> +					ARRAY_SIZE(rt9455_charger_supplied_to);
> +	ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +					rt9455_irq_handler_thread,
> +					IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +					RT9455_DRIVER_NAME, info);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to register IRQ handler\n");
> +		return ret;
> +	}
> +
> +	ret = rt9455_hw_init(info, ichrg, ieoc_percentage, voreg, mivr, iaicr);
> +	if (ret) {
> +		dev_err(dev, "Failed to set charger to its default values\n");
> +		return ret;
> +	}
> +
> +	info->charger = power_supply_register(dev, &rt9455_charger_desc,
> +					      &rt9455_charger_config);
> +	if (IS_ERR(info->charger)) {
> +		dev_err(dev, "Failed to register charger\n");
> +		ret = PTR_ERR(info->charger);
> +		goto put_usb_phy;
> +	}
> +
> +	return 0;
> +
> +put_usb_phy:
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +	if (!IS_ERR_OR_NULL(info->usb_phy))  {
> +		usb_unregister_notifier(info->usb_phy, &info->nb);
> +		usb_put_phy(info->usb_phy);
> +	}
> +#endif
> +	return ret;
> +}
> +
> +static int rt9455_remove(struct i2c_client *client)
> +{
> +	int ret;
> +	struct rt9455_info *info = i2c_get_clientdata(client);
> +
> +	ret = rt9455_register_reset(info);
> +	if (ret)
> +		dev_err(&info->client->dev, "Failed to set charger to its default values\n");
> +
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +	if (!IS_ERR_OR_NULL(info->usb_phy)) {
> +		usb_unregister_notifier(info->usb_phy, &info->nb);
> +		usb_put_phy(info->usb_phy);
> +	}
> +#endif
> +
> +	cancel_delayed_work_sync(&info->pwr_rdy_work);
> +	cancel_delayed_work_sync(&info->max_charging_time_work);
> +	cancel_delayed_work_sync(&info->batt_presence_work);
> +
> +	power_supply_unregister(info->charger);
> +
> +	return ret;
> +}
> +
> +static const struct i2c_device_id rt9455_i2c_id_table[] = {
> +	{ RT9455_DRIVER_NAME, 0 },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, rt9455_i2c_id_table);
> +
> +static const struct of_device_id rt9455_of_match[] = {
> +	{ .compatible = "richtek,rt9455", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, rt9455_of_match);
> +
> +static const struct acpi_device_id rt9455_i2c_acpi_match[] = {
> +	{ "RT945500", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, rt9455_i2c_acpi_match);
> +
> +static struct i2c_driver rt9455_driver = {
> +	.probe		= rt9455_probe,
> +	.remove		= rt9455_remove,
> +	.id_table	= rt9455_i2c_id_table,
> +	.driver = {
> +		.name		= RT9455_DRIVER_NAME,
> +		.of_match_table	= of_match_ptr(rt9455_of_match),
> +		.acpi_match_table = ACPI_PTR(rt9455_i2c_acpi_match),
> +	},
> +};
> +module_i2c_driver(rt9455_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Anda-Maria Nicolae <anda-maria.nicolae@intel.com>");
> +MODULE_ALIAS("i2c:rt9455-charger");
> +MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
> -- 
> 1.7.9.5
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 8+ messages in thread

* RE: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-04-30  7:53 ` Krzysztof Kozlowski
@ 2015-05-04 12:48   ` Nicolae, Anda-maria
  0 siblings, 0 replies; 8+ messages in thread
From: Nicolae, Anda-maria @ 2015-05-04 12:48 UTC (permalink / raw)
  To: Krzysztof Kozlowski
  Cc: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

Hi Krzysztof,

Inline are the answers to your questions.

Thanks,
Anda

________________________________________
From: k.kozlowski.k@gmail.com [k.kozlowski.k@gmail.com] on behalf of Krzysztof Kozlowski [k.kozlowski@samsung.com]
Sent: Thursday, April 30, 2015 10:53 AM
To: Nicolae, Anda-maria
Cc: sre@kernel.org; dbaryshkov@gmail.com; robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; ijc+devicetree@hellion.org.uk; galak@codeaurora.org; dwmw2@infradead.org; linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; devicetree@vger.kernel.org
Subject: Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger

2015-04-30 5:13 GMT+09:00 Anda-Maria Nicolae <anda-maria.nicolae@intel.com>:
> Based on the datasheet found here:
> http://www.richtek.com/download_ds.jsp?p=RT9455
>
> Updates from the previous version:
> - replaced license GPLv2 with GPL
> - replaced vendor prefix rt with richtek
> - replaced uppercase properties names from devicetree with lowercase separated by dash properties names
> - replaced I/O read/write API with regmap_read/write and regmap_field_read/write
> - used kernel multiline comment
> - used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.

I think when device is suspended (e.g. to RAM) no work will ever be
executed. The timers (for delayed work) will not wake up the device...
RTC could wake but this is different story. My proposal of deferred
timers is affected by idle CPU time. Are you sure that you want to
wake up from the system suspend?

Oh, now I better understand it. I don't think I need this feature. Also, the expire times that I use in the driver are not defined in the datasheet, so it should not be a problem if they are fired later.
So, I will use INIT_DEFERRABLE_WORK instead of INIT_DELAYED_WORK.

> - replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc
> - replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
> - replaced {"RTK9455", 0} with { "RTK9455", 0 }
> - removed .owner = THIS_MODULE
>
> Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>

You missed some of my comments. I mentioned wrong error paths around
put_usb_phy in probe. They do not seem to be fixed...

Now I see what you meant. I looked at usb_get_phy() implementation and I saw that I cannot return NULL. So I replaced IS_ERR_OR_NULL() with IS_ERR(). I did this in rt9455_remove() and in rt9455_irq_handler_thread() functions, too.
Also, this replacement (IS_ERR() instead of IS_ERR_OR_NULL()) should also be done in other power charger drivers: 
drivers/power/pda_power.c lines 319, 375, 410, 445; 
drivers/power/ab8500_charger.c line 3651;
drivers/power/twl4030_charger.c lines 642, 674 and 706.
I will send the patch for RT9455 charger soon. I will also send a patch to replace IS_ERR_OR_NULL() with IS_ERR() in the drivers listed above.



Just one hint - mostly new bindings are posted in separate patches at
the beginning of the patchset. I actually don't mind. but separating
them will probably give you higher chance of review from DT people.
This is also mentioned in:
Documentation/devicetree/bindings/submitting-patches.txt

Best regards,
Krzysztof

^ permalink raw reply	[flat|nested] 8+ messages in thread

* RE: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-04-30  9:16 ` Laurentiu Palcu
@ 2015-05-04 14:12   ` Nicolae, Anda-maria
  2015-05-04 15:22     ` Laurentiu Palcu
  0 siblings, 1 reply; 8+ messages in thread
From: Nicolae, Anda-maria @ 2015-05-04 14:12 UTC (permalink / raw)
  To: Palcu, Laurentiu
  Cc: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

Hi Laurentiu,

Inline are the responses to your comments.

Thanks,
Anda

________________________________________
From: Palcu, Laurentiu
Sent: Thursday, April 30, 2015 12:16 PM
To: Nicolae, Anda-maria
Cc: sre@kernel.org; dbaryshkov@gmail.com; robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; ijc+devicetree@hellion.org.uk; galak@codeaurora.org; dwmw2@infradead.org; linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; devicetree@vger.kernel.org
Subject: Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger

More comments inline.

laurentiu

On Wed, Apr 29, 2015 at 11:13:26PM +0300, Anda-Maria Nicolae wrote:
> Based on the datasheet found here:
> http://www.richtek.com/download_ds.jsp?p=RT9455
>
> Updates from the previous version:
> - replaced license GPLv2 with GPL
> - replaced vendor prefix rt with richtek
> - replaced uppercase properties names from devicetree with lowercase separated by dash properties names
> - replaced I/O read/write API with regmap_read/write and regmap_field_read/write
> - used kernel multiline comment
> - used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.
> - replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc
> - replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
> - replaced {"RTK9455", 0} with { "RTK9455", 0 }
> - removed .owner = THIS_MODULE
The change log should go after '---'.  Otherwise it will end up in the
commit message.

WIll do.

>
> Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
> ---
>  .../devicetree/bindings/power/rt9455_charger.txt   |   43 +
>  .../devicetree/bindings/vendor-prefixes.txt        |    1 +
>  drivers/power/Kconfig                              |    6 +
>  drivers/power/Makefile                             |    1 +
>  drivers/power/rt9455_charger.c                     | 1758 ++++++++++++++++++++
>  5 files changed, 1809 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/rt9455_charger.txt
>  create mode 100644 drivers/power/rt9455_charger.c
(...)

>
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 4091fb0..39f208d 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -439,6 +439,12 @@ config BATTERY_RT5033
>         The fuelgauge calculates and determines the battery state of charge
>         according to battery open circuit voltage.
>
> +config CHARGER_RT9455
> +     tristate "Richtek RT9455 battery charger driver"
> +     depends on I2C && GPIOLIBa
depends on REGMAP_I2C

> +     help
> +     Say Y to enable support for the Richtek RT9455 battery charger.
> +
>  source "drivers/power/reset/Kconfig"
>
>  endif # POWER_SUPPLY
(...)

> diff --git a/drivers/power/rt9455_charger.c b/drivers/power/rt9455_charger.c
> new file mode 100644
> index 0000000..e45b0f2
> --- /dev/null
> +++ b/drivers/power/rt9455_charger.c
> @@ -0,0 +1,1758 @@
> +/*
> + * Driver for Richtek RT9455WSC battery charger.
> + *
> + * Copyright (C) 2015 Intel Corporation
> + *
> + * 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/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/power_supply.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/acpi.h>
> +#include <linux/usb/phy.h>
> +#include <linux/regmap.h>
> +
> +#define RT9455_MANUFACTURER                  "Richtek"
> +#define RT9455_MODEL_NAME                    "RT9455"
> +#define RT9455_DRIVER_NAME                   "rt9455-charger"
> +
> +#define RT9455_IRQ_NAME                              "interrupt"
> +
> +#define RT9455_PWR_RDY_DELAY                 1 /* 1 second */
> +#define RT9455_MAX_CHARGING_TIME             21600 /* 6 hrs */
> +#define RT9455_BATT_PRESENCE_DELAY           60 /* 60 seconds */
> +
> +#define RT9455_CHARGE_MODE                   0x00
> +#define RT9455_BOOST_MODE                    0x01
> +
> +#define RT9455_FAULT                         0x03
> +
> +#define RT9455_IAICR_100MA                   0x00
> +#define RT9455_IAICR_500MA                   0x01
> +#define RT9455_IAICR_NO_LIMIT                        0x03
> +
> +#define RT9455_CHARGE_DISABLE                        0x00
> +#define RT9455_CHARGE_ENABLE                 0x01
> +
> +#define RT9455_PWR_FAULT                     0x00
> +#define RT9455_PWR_GOOD                              0x01
> +
> +#define RT9455_REG_CTRL1                     0x00 /* CTRL1 reg address */
> +#define RT9455_REG_CTRL1_STAT_MASK           (BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL1_BOOST_MASK          BIT(3)
> +#define RT9455_REG_CTRL1_PWR_RDY_MASK                BIT(2)
> +#define RT9455_REG_CTRL1_OTG_PIN_POLARITY_MASK       BIT(1)
Since you're using regmap fields, you can get rid of the masks above.
The same applies for the masks below (except those for the IRQ
registers which you seem to use).

I let them there for further use, in case enhancements will be done.

> +
> +#define RT9455_REG_CTRL2                     0x01 /* CTRL2 reg address */
> +#define RT9455_REG_CTRL2_IAICR_MASK          (BIT(7) | BIT(6))
> +#define RT9455_REG_CTRL2_TE_SHDN_EN_MASK     BIT(5)
> +#define RT9455_REG_CTRL2_HIGHER_OCP_MASK     BIT(4)
> +#define RT9455_REG_CTRL2_TE_MASK             BIT(3)
> +#define RT9455_REG_CTRL2_IAICR_INT_MASK              BIT(2)
> +#define RT9455_REG_CTRL2_HIZ_MASK            BIT(1)
> +#define RT9455_REG_CTRL2_OPA_MODE_MASK               BIT(0)
> +
> +#define RT9455_REG_CTRL3                     0x02 /* CTRL3 reg address */
> +#define RT9455_REG_CTRL3_VOREG_MASK          (BIT(7) | BIT(6) | BIT(5) | \
> +                                              BIT(4) | BIT(3) | BIT(2))
> +#define RT9455_REG_CTRL3_OTG_PL_MASK         BIT(1)
> +#define RT9455_REG_CTRL3_OTG_EN_MASK         BIT(0)
> +
> +#define RT9455_REG_DEV_ID                    0x03 /* DEV_ID reg address */
> +#define RT9455_REG_DEV_ID_VENDOR_ID_MASK     (BIT(7) | BIT(6) | BIT(5) | \
> +                                              BIT(4))
> +#define RT9455_REG_DEV_ID_CHIP_REV_MASK              (BIT(3) | BIT(2) | BIT(1) | \
> +                                              BIT(0))
> +
> +#define RT9455_REG_CTRL4                     0x04 /* CTRL4 reg address */
> +#define RT9455_REG_CTRL4_RST_MASK            BIT(7)
> +
> +#define RT9455_REG_CTRL5                     0x05 /* CTRL5 reg address */
> +#define RT9455_REG_CTRL5_TMR_EN_MASK         BIT(7)
> +#define RT9455_REG_CTRL5_MIVR_MASK           (BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL5_IPREC_MASK          (BIT(3) | BIT(2))
> +#define RT9455_REG_CTRL5_IEOC_PERCENTAGE_MASK        (BIT(1) | BIT(0))
> +
> +#define RT9455_REG_CTRL6                     0x06 /* CTRL6 reg address */
> +#define RT9455_REG_CTRL6_IAICR_SEL_MASK              BIT(7)
> +#define RT9455_REG_CTRL6_ICHRG_MASK          (BIT(6) | BIT(5) | BIT(4))
> +#define RT9455_REG_CTRL6_VPREC_MASK          (BIT(2) | BIT(1) | BIT(0))
> +
> +#define RT9455_REG_CTRL7                     0x07 /* CTRL7 reg address */
> +#define RT9455_REG_CTRL7_BATD_EN_MASK                BIT(6)
> +#define RT9455_REG_CTRL7_CHG_EN_MASK         BIT(4)
> +#define RT9455_REG_CTRL7_VMREG_MASK          (BIT(3) | BIT(2) | BIT(1) | \
> +                                              BIT(0))
> +
> +#define RT9455_REG_IRQ1                              0x08 /* IRQ1 reg address */
> +#define RT9455_REG_IRQ1_TSDI_MASK            BIT(7)
> +#define RT9455_REG_IRQ1_VINOVPI_MASK         BIT(6)
> +#define RT9455_REG_IRQ1_BATAB_MASK           BIT(0)
> +
> +#define RT9455_REG_IRQ2                              0x09 /* IRQ2 reg address */
> +#define RT9455_REG_IRQ2_CHRVPI_MASK          BIT(7)
> +#define RT9455_REG_IRQ2_CHBATOVI_MASK                BIT(5)
> +#define RT9455_REG_IRQ2_CHTERMI_MASK         BIT(4)
> +#define RT9455_REG_IRQ2_CHRCHGI_MASK         BIT(3)
> +#define RT9455_REG_IRQ2_CH32MI_MASK          BIT(2)
> +#define RT9455_REG_IRQ2_CHTREGI_MASK         BIT(1)
> +#define RT9455_REG_IRQ2_CHMIVRI_MASK         BIT(0)
> +
> +#define RT9455_REG_IRQ3                              0x0A /* IRQ3 reg address */
> +#define RT9455_REG_IRQ3_BSTBUSOVI_MASK               BIT(7)
> +#define RT9455_REG_IRQ3_BSTOLI_MASK          BIT(6)
> +#define RT9455_REG_IRQ3_BSTLOWVI_MASK                BIT(5)
> +#define RT9455_REG_IRQ3_BST32SI_MASK         BIT(3)
> +
> +#define RT9455_REG_MASK1                     0x0B /* MASK1 reg address */
> +#define RT9455_REG_MASK1_TSDM_MASK           BIT(7)
> +#define RT9455_REG_MASK1_VINOVPIM_MASK               BIT(6)
> +#define RT9455_REG_MASK1_BATABM_MASK         BIT(0)
> +
> +#define RT9455_REG_MASK2                     0x0C /* MASK2 reg address */
> +#define RT9455_REG_MASK2_CHRVPIM_MASK                BIT(7)
> +#define RT9455_REG_MASK2_CHBATOVIM_MASK              BIT(5)
> +#define RT9455_REG_MASK2_CHTERMIM_MASK               BIT(4)
> +#define RT9455_REG_MASK2_CHRCHGIM_MASK               BIT(3)
> +#define RT9455_REG_MASK2_CH32MIM_MASK                BIT(2)
> +#define RT9455_REG_MASK2_CHTREGIM_MASK               BIT(1)
> +#define RT9455_REG_MASK2_CHMIVRIM_MASK               BIT(0)
> +
> +#define RT9455_REG_MASK3                     0x0D /* MASK3 reg address */
> +#define RT9455_REG_MASK3_BSTVINOVIM_MASK     BIT(7)
> +#define RT9455_REG_MASK3_BSTOLIM_MASK                BIT(6)
> +#define RT9455_REG_MASK3_BSTLOWVIM_MASK              BIT(5)
> +#define RT9455_REG_MASK3_BST32SIM_MASK               BIT(3)
> +
> +enum rt9455_fields {
> +     F_STAT, F_BOOST, F_PWR_RDY, F_OTG_PIN_POLARITY, /* CTRL1 reg fields */
> +
> +     F_IAICR, F_TE_SHDN_EN, F_HIGHER_OCP, F_TE, F_IAICR_INT, F_HIZ,
> +     F_OPA_MODE, /* CTRL2 reg fields */
> +
> +     F_VOREG, F_OTG_PL, F_OTG_EN, /* CTRL3 reg fields */
> +
> +     F_VENDOR_ID, F_CHIP_REV, /* DEV_ID reg fields */
> +
> +     F_RST, /* CTRL4 reg fields */
> +
> +     F_TMR_EN, F_MIVR, F_IPREC, F_IEOC_PERCENTAGE, /* CTRL5 reg fields*/
> +
> +     F_IAICR_SEL, F_ICHRG, F_VPREC, /* CTRL6 reg fields */
> +
> +     F_BATD_EN, F_CHG_EN, F_VMREG, /* CTRL7 reg fields */
> +
> +     F_TSDI, F_VINOVPI, F_BATAB, /* IRQ1 reg fields */
> +
> +     F_CHRVPI, F_CHBATOVI, F_CHTERMI, F_CHRCHGI, F_CH32MI, F_CHTREGI,
> +     F_CHMIVRI, /* IRQ2 reg fields */
> +
> +     F_BSTBUSOVI, F_BSTOLI, F_BSTLOWVI, F_BST32SI, /* IRQ3 reg fields */
> +
> +     F_TSDM, F_VINOVPIM, F_BATABM, /* MASK1 reg fields */
> +
> +     F_CHRVPIM, F_CHBATOVIM, F_CHTERMIM, F_CHRCHGIM, F_CH32MIM, F_CHTREGIM,
> +     F_CHMIVRIM, /* MASK2 reg fields */
> +
> +     F_BSTVINOVIM, F_BSTOLIM, F_BSTLOWVIM, F_BST32SIM, /* MASK3 reg fields */
> +
> +     F_MAX_FIELDS
> +};
> +
> +static const struct reg_field rt9455_reg_fields[] = {
> +     [F_STAT]                = REG_FIELD(RT9455_REG_CTRL1, 4, 5),
> +     [F_BOOST]               = REG_FIELD(RT9455_REG_CTRL1, 3, 3),
> +     [F_PWR_RDY]             = REG_FIELD(RT9455_REG_CTRL1, 2, 2),
> +     [F_OTG_PIN_POLARITY]    = REG_FIELD(RT9455_REG_CTRL1, 1, 1),
> +
> +     [F_IAICR]               = REG_FIELD(RT9455_REG_CTRL2, 6, 7),
> +     [F_TE_SHDN_EN]          = REG_FIELD(RT9455_REG_CTRL2, 5, 5),
> +     [F_HIGHER_OCP]          = REG_FIELD(RT9455_REG_CTRL2, 4, 4),
> +     [F_TE]                  = REG_FIELD(RT9455_REG_CTRL2, 3, 3),
> +     [F_IAICR_INT]           = REG_FIELD(RT9455_REG_CTRL2, 2, 2),
> +     [F_HIZ]                 = REG_FIELD(RT9455_REG_CTRL2, 1, 1),
> +     [F_OPA_MODE]            = REG_FIELD(RT9455_REG_CTRL2, 0, 0),
> +
> +     [F_VOREG]               = REG_FIELD(RT9455_REG_CTRL3, 2, 7),
> +     [F_OTG_PL]              = REG_FIELD(RT9455_REG_CTRL3, 1, 1),
> +     [F_OTG_EN]              = REG_FIELD(RT9455_REG_CTRL3, 0, 0),
> +
> +     [F_VENDOR_ID]           = REG_FIELD(RT9455_REG_DEV_ID, 4, 7),
> +     [F_CHIP_REV]            = REG_FIELD(RT9455_REG_DEV_ID, 0, 3),
> +
> +     [F_RST]                 = REG_FIELD(RT9455_REG_CTRL4, 7, 7),
> +
> +     [F_TMR_EN]              = REG_FIELD(RT9455_REG_CTRL5, 7, 7),
> +     [F_MIVR]                = REG_FIELD(RT9455_REG_CTRL5, 4, 5),
> +     [F_IPREC]               = REG_FIELD(RT9455_REG_CTRL5, 2, 3),
> +     [F_IEOC_PERCENTAGE]     = REG_FIELD(RT9455_REG_CTRL5, 0, 1),
> +
> +     [F_IAICR_SEL]           = REG_FIELD(RT9455_REG_CTRL6, 7, 7),
> +     [F_ICHRG]               = REG_FIELD(RT9455_REG_CTRL6, 4, 6),
> +     [F_VPREC]               = REG_FIELD(RT9455_REG_CTRL6, 0, 2),
> +
> +     [F_BATD_EN]             = REG_FIELD(RT9455_REG_CTRL7, 6, 6),
> +     [F_CHG_EN]              = REG_FIELD(RT9455_REG_CTRL7, 4, 4),
> +     [F_VMREG]               = REG_FIELD(RT9455_REG_CTRL7, 0, 3),
> +
> +     [F_TSDI]                = REG_FIELD(RT9455_REG_IRQ1, 7, 7),
> +     [F_VINOVPI]             = REG_FIELD(RT9455_REG_IRQ1, 6, 6),
> +     [F_BATAB]               = REG_FIELD(RT9455_REG_IRQ1, 0, 0),
> +
> +     [F_CHRVPI]              = REG_FIELD(RT9455_REG_IRQ2, 7, 7),
> +     [F_CHBATOVI]            = REG_FIELD(RT9455_REG_IRQ2, 5, 5),
> +     [F_CHTERMI]             = REG_FIELD(RT9455_REG_IRQ2, 4, 4),
> +     [F_CHRCHGI]             = REG_FIELD(RT9455_REG_IRQ2, 3, 3),
> +     [F_CH32MI]              = REG_FIELD(RT9455_REG_IRQ2, 2, 2),
> +     [F_CHTREGI]             = REG_FIELD(RT9455_REG_IRQ2, 1, 1),
> +     [F_CHMIVRI]             = REG_FIELD(RT9455_REG_IRQ2, 0, 0),
> +
> +     [F_BSTBUSOVI]           = REG_FIELD(RT9455_REG_IRQ3, 7, 7),
> +     [F_BSTOLI]              = REG_FIELD(RT9455_REG_IRQ3, 6, 6),
> +     [F_BSTLOWVI]            = REG_FIELD(RT9455_REG_IRQ3, 5, 5),
> +     [F_BST32SI]             = REG_FIELD(RT9455_REG_IRQ3, 3, 3),
I don't see any benefit in declaring fields for the IRQx registers, since
you're not going to use them. AFAICS you're reading the entire IRQx
registers and then use masks to retrieve the fields.

I let them there for symmetry and further use, in case enhancements will be done. I prefer using predefined masks instead of fields from struct reg_field when dealing with interrupt registers. The interrupt handler performs numerous checks and I believe the masks are faster than accessing fields from an array of reg_fields.

> +
> +     [F_TSDM]                = REG_FIELD(RT9455_REG_MASK1, 7, 7),
> +     [F_VINOVPIM]            = REG_FIELD(RT9455_REG_MASK1, 6, 6),
> +     [F_BATABM]              = REG_FIELD(RT9455_REG_MASK1, 0, 0),
> +
> +     [F_CHRVPIM]             = REG_FIELD(RT9455_REG_MASK2, 7, 7),
> +     [F_CHBATOVIM]           = REG_FIELD(RT9455_REG_MASK2, 5, 5),
> +     [F_CHTERMIM]            = REG_FIELD(RT9455_REG_MASK2, 4, 4),
> +     [F_CHRCHGIM]            = REG_FIELD(RT9455_REG_MASK2, 3, 3),
> +     [F_CH32MIM]             = REG_FIELD(RT9455_REG_MASK2, 2, 2),
> +     [F_CHTREGIM]            = REG_FIELD(RT9455_REG_MASK2, 1, 1),
> +     [F_CHMIVRIM]            = REG_FIELD(RT9455_REG_MASK2, 0, 0),
> +
> +     [F_BSTVINOVIM]          = REG_FIELD(RT9455_REG_MASK3, 7, 7),
> +     [F_BSTOLIM]             = REG_FIELD(RT9455_REG_MASK3, 6, 6),
> +     [F_BSTLOWVIM]           = REG_FIELD(RT9455_REG_MASK3, 5, 5),
> +     [F_BST32SIM]            = REG_FIELD(RT9455_REG_MASK3, 3, 3),
> +};
> +
> +/*
> + * Each array initialised below shows the possible real-world values for a
> + * group of bits belonging to RT9455 registers. The arrays are sorted in
> + * ascending order. The index of each real-world value represents the value
> + * that is encoded in the group of bits belonging to RT9455 registers.
> + */
> +/* REG06[6:4] (ICHRG) in uAh */
> +static const int rt9455_ichrg_values[] = {
> +      500000,  650000,  800000,  950000, 1100000, 1250000, 1400000, 1550000
> +};
> +
> +/* REG02[7:2] (VOREG) in uV */
> +static const int rt9455_voreg_values[] = {
> +     3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
> +     3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
> +     3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
> +     3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
> +     4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
> +     4300000, 4330000, 4350000, 4370000, 4390000, 4410000, 4430000, 4450000,
> +     4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000,
> +     4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000
> +};
> +
> +/* REG07[3:0] (VMREG) in uV */
> +static const int rt9455_vmreg_values[] = {
> +     4200000, 4220000, 4240000, 4260000, 4280000, 4300000, 4320000, 4340000,
> +     4360000, 4380000, 4400000, 4430000, 4450000, 4450000, 4450000, 4450000
> +};
> +
> +/* REG05[5:4] (IEOC_PERCENTAGE) */
> +static const int rt9455_ieoc_percentage_values[] = {
> +     10, 30, 20, 30
> +};
> +
> +/* REG05[1:0] (MIVR) in uV */
> +static const int rt9455_mivr_values[] = {
> +     4000000, 4250000, 4500000, 5000000
> +};
> +
> +/* REG05[1:0] (IAICR) in uA */
> +static const int rt9455_iaicr_values[] = {
> +     100000, 500000, 1000000, 2000000
> +};
> +
> +struct rt9455_info {
> +     struct i2c_client               *client;
> +     struct regmap                   *regmap;
> +     struct regmap_field             *regmap_fields[F_MAX_FIELDS];
> +     struct power_supply             *charger;
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +     struct usb_phy                  *usb_phy;
> +     struct notifier_block           nb;
> +#endif
> +     struct gpio_desc                *gpiod_irq;
> +     unsigned int                    gpio_irq;
> +     struct delayed_work             pwr_rdy_work;
> +     struct delayed_work             max_charging_time_work;
> +     struct delayed_work             batt_presence_work;
> +};
> +
> +static const struct regmap_config rt9455_regmap_config = {
> +     .reg_bits = 8,
> +     .val_bits = 8,
> +     .max_register = RT9455_REG_MASK3,
> +};
Do you need all chip's registers to be volatile? Can we cache any of
them so we don't make unnecessary read operations on the I2C bus?

I can cache reg 0x03 and reg 0x05. 

(...)
> +
> +static int rt9455_charger_get_status(struct rt9455_info *info,
> +                                  union power_supply_propval *val)
> +{
> +     unsigned int v;
> +     int ret;
> +
> +     ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
> +     if (ret) {
> +             dev_err(&info->client->dev, "Failed to read STAT bits\n");
> +             return ret;
> +     }
> +
> +     switch (v) {
> +     case 0:
> +             val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +     break;
> +     case 1:
> +             val->intval = POWER_SUPPLY_STATUS_CHARGING;
> +     break;
> +     case 2:
> +             val->intval = POWER_SUPPLY_STATUS_FULL;
> +     break;
> +     default:
> +             val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
> +     break;
> +     }
Please indent the breaks to conform to kernel coding style.

Will do.

Also, just an idea, maybe you should also return
POWER_SUPPLY_STATUS_DISCHARGING when the power is not plugged in
because, technically, if PWR_RDY=0 the battery will discharge...

There are cases in which power source can be plugged in (PWR_RDY bit is 1) and the battery is not being charged. These are: the charge bit is cleared (set to 0), or the battery is already full (in this case, STAT bits value is 2).
Also, when the battery is not connected to the charger, STAT bits value is either 3 or 0. So if I return POWER_SUPPLY_STATUS_DISCHARGING, I also have to check whether the battery is connected or not.
In addition to this, I also believe that POWER_SUPPLY_STATUS_DISCHARGING should be returned when the charger is neither in sleep mode, nor in high impedance mode (so there is additional check to do). In both modes, the charger tries to operate with minimum current from the battery, to prevent battery drain. So theoretically, the current drawn by the charger from the battery can be considered as negligible. 
This is why I prefer to return POWER_SUPPLY_STATUS_NOT_CHARGING.

(...)

> +
> +static int rt9455_charger_get_voltage_max(struct rt9455_info *info,
> +                                       union power_supply_propval *val)
> +{
> +     int idx = ARRAY_SIZE(rt9455_voreg_values) - 1;
rt9455_vmreg_values?

> +
> +     val->intval = rt9455_voreg_values[idx];
ditto.

Since I set TE and TE_SHDN_EN, the charging terminates if the charge current is below termination current (IEOC) in constant voltage mode. From my experiments, charging is done when battery voltage is almost equal to VOREG. Therefore, the battery voltage never reaches VMREG in this configuration. This is why I use maximum VOREG value instead of VMREG. If I do not set TE or TE_SHDN_EN bit, the charger will not trigger any interrupt when charging is done.

> +
> +     return 0;
> +}
(...)
> +
> +static int rt9455_charger_get_property(struct power_supply *psy,
> +                                    enum power_supply_property psp,
> +                                    union power_supply_propval *val)
> +{
> +     struct rt9455_info *info = power_supply_get_drvdata(psy);
> +
> +     switch (psp) {
> +     case POWER_SUPPLY_PROP_STATUS:
> +             return rt9455_charger_get_status(info, val);
> +     case POWER_SUPPLY_PROP_HEALTH:
> +             return rt9455_charger_get_health(info, val);
> +     case POWER_SUPPLY_PROP_PRESENT:
> +             return rt9455_charger_get_battery_presence(info, val);
> +     case POWER_SUPPLY_PROP_ONLINE:
> +             return rt9455_charger_get_online(info, val);
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +             return rt9455_charger_get_current(info, val);
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
> +             return rt9455_charger_get_current_max(info, val);
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> +             return rt9455_charger_get_voltage(info, val);
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> +             return rt9455_charger_get_voltage_max(info, val);
> +     case POWER_SUPPLY_PROP_SCOPE:
> +             val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
> +             return 0;
> +     case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
> +             return rt9455_charger_get_term_current(info, val);
> +     case POWER_SUPPLY_PROP_MODEL_NAME:
> +             val->strval = RT9455_MODEL_NAME;
> +             return 0;
> +     case POWER_SUPPLY_PROP_MANUFACTURER:
> +             val->strval = RT9455_MANUFACTURER;
> +             return 0;
> +     default:
> +             return -ENODATA;
> +     }
> +}
> +
(...)
> +
> +static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
> +                                       const union power_supply_propval *val)
> +{
> +     return rt9455_set_field_val(info, F_VMREG,
> +                                 rt9455_vmreg_values,
> +                                 ARRAY_SIZE(rt9455_vmreg_values),
> +                                 val->intval);
> +}
> +
> +static int rt9455_charger_set_property(struct power_supply *psy,
> +                                    enum power_supply_property psp,
> +                                    const union power_supply_propval *val)
> +{
> +     struct rt9455_info *info = power_supply_get_drvdata(psy);
> +
> +     switch (psp) {
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +             return rt9455_charger_set_current(info, val);
> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> +             return rt9455_charger_set_voltage(info, val);
Personally, I'm against having these properties writable. A user might
play with the charging voltage or current and then complain that the
battery does not charge at all, or it takes ages to charge. I'd leave
these to be set by manufacturer through DT/ACPI. But, it's just an
opinion.

If the user really wants to damage his/her battery, he/she can charge the values from DT/ACPI. Also, numerous charger drivers expose these properties as writable.
I prefer leaving them as they are.

> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> +             return rt9455_charger_set_voltage_max(info, val);
You set the max voltage here, but rt9455_charger_get_voltage_max()
returns the maximum allowed value. Shouldn't it return the value you
just set here?

Max VOREG value equals max VMREG value (4.45V). I agree that it is confusing and I will use VOREG in both places.

> +     default:
> +             return -EINVAL;
> +     }
> +}
> +
(...)

> +
> +static int rt9455_usb_event_none(struct rt9455_info *info,
> +                              u8 opa_mode, u8 iaicr)
> +{
> +     struct device *dev = &info->client->dev;
> +     int ret;
> +
> +     if (opa_mode == RT9455_BOOST_MODE) {
> +             /*
> +              * If the charger is in boost mode, and it has received
> +              * USB_EVENT_NONE, this means the consumer device powered by the
> +              * charger is not connected anymore.
> +              * In this case, the charger goes into charge mode.
> +              */
> +             dev_dbg(dev, "USB_EVENT_NONE received, therefore the charger goes into charge mode\n");
Do you really need both the comment and the dev_dbg? The latter seems
explanatory enough, even though I'd shorten it a little: "USB_EVENT_NONE
received, enter charge mode". The same goes for the next 4 functions.

Yes. The comment explains the purpose of the function, while the dev_dbg can be activated to be shown in dmesg. Dev_dbg can be activated to check if the driver really enters in the respective function, in case a bug/issue occurs.

> +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +                                      RT9455_CHARGE_MODE);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set charger in charge mode\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     dev_dbg(dev, "USB_EVENT_NONE received, therefore IAICR is set to its minimum value\n");
> +     if (iaicr != RT9455_IAICR_100MA) {
> +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +                                      RT9455_IAICR_100MA);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set IAICR value\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_vbus(struct rt9455_info *info,
> +                              u8 opa_mode, u8 iaicr)
> +{
> +     struct device *dev = &info->client->dev;
> +     int ret;
> +
> +     if (opa_mode == RT9455_BOOST_MODE) {
> +             /*
> +              * If the charger is in boost mode, and it has received
> +              * USB_EVENT_VBUS, this means the consumer device powered by the
> +              * charger is not connected anymore.
> +              * In this case, the charger goes into charge mode.
> +              */
> +             dev_dbg(dev, "USB_EVENT_VBUS received, therefore the charger goes into charge mode\n");
> +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +                                      RT9455_CHARGE_MODE);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set charger in charge mode\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     dev_dbg(dev, "USB_EVENT_VBUS received, therefore IAICR is set to 500 mA\n");
> +     if (iaicr != RT9455_IAICR_500MA) {
> +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +                                      RT9455_IAICR_500MA);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set IAICR value\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_id(struct rt9455_info *info,
> +                            u8 opa_mode, u8 iaicr)
> +{
> +     struct device *dev = &info->client->dev;
> +     int ret;
> +
> +     if (opa_mode == RT9455_CHARGE_MODE) {
> +             /*
> +              * If the charger is in charge mode, and it has received
> +              * USB_EVENT_ID, this means the consumer device powered by the
> +              * charger is not connected anymore.
> +              * In this case, the charger goes into charge mode.
s/goes into charge mode/goes into boost mode/

Will correct comment.

> +              */
> +             dev_dbg(dev, "USB_EVENT_ID received, therefore the charger goes into boost mode\n");
> +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +                                      RT9455_BOOST_MODE);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set charger in boost mode\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     dev_dbg(dev, "USB_EVENT_ID received, therefore IAICR is set to its minimum value\n");
> +     if (iaicr != RT9455_IAICR_100MA) {
> +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +                                      RT9455_IAICR_100MA);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set IAICR value\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     return NOTIFY_OK;
> +}
> +
> +static int rt9455_usb_event_charger(struct rt9455_info *info,
> +                                 u8 opa_mode, u8 iaicr)
> +{
> +     struct device *dev = &info->client->dev;
> +     int ret;
> +
> +     if (opa_mode == RT9455_BOOST_MODE) {
> +             /*
> +              * If the charger is in boost mode, and it has received
> +              * USB_EVENT_CHARGER, this means the consumer device powered by
> +              * the charger is not connected anymore.
> +              * In this case, the charger goes into charge mode.
> +              */
> +             dev_dbg(dev, "USB_EVENT_CHARGER received, therefore the charger goes into charge mode\n");
> +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> +                                      RT9455_CHARGE_MODE);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set charger in charge mode\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     dev_dbg(dev, "USB_EVENT_CHARGER received, therefore IAICR is set to no current limit\n");
> +     if (iaicr != RT9455_IAICR_NO_LIMIT) {
> +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> +                                      RT9455_IAICR_NO_LIMIT);
> +             if (ret) {
> +                     dev_err(dev, "Failed to set IAICR value\n");
> +                     return NOTIFY_DONE;
> +             }
> +     }
> +
> +     return NOTIFY_OK;
> +}
> +
(...)
> +
> +static void rt9455_max_charging_time_work_callback(struct work_struct *work)
> +{
> +     struct rt9455_info *info = container_of(work, struct rt9455_info,
> +                                             max_charging_time_work.work);
> +     struct device *dev = &info->client->dev;
> +     int ret;
> +
> +     dev_err(dev, "Battery has been charging for at least 6 hours and is not yet fully charged. Battery is dead, therefore charging is disabled.\n");
If battery is not charged in 6 hours may not necessarily mean that it's
dead... Perhaps a low charge current was set. So, why not shorten this
to just: "Safety timer expired, disable charging."

I prefer leaving it as it is. Safety timer refers to something else; RT9455 charger has a built-in safety timer which disables charging when no I2C read/write is done within 32 mins. The user may believe that this built-in timer expired, Also, when the charger is connected to a power source, minimum value for input current is 500 mA while minimum value for output current is also 500 mA. I believe this should be enough to charge a good battery in 6 hrs.

> +     ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
> +                              RT9455_CHARGE_DISABLE);
> +     if (ret)
> +             dev_err(dev, "Failed to disable charging\n");
> +}
> +
> +static void rt9455_batt_presence_work_callback(struct work_struct *work)
> +{
> +     struct rt9455_info *info = container_of(work, struct rt9455_info,
> +                                             batt_presence_work.work);
> +     struct device *dev = &info->client->dev;
> +     unsigned int irq1, mask1;
> +     int ret;
> +
> +     ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
> +     if (ret) {
> +             dev_err(dev, "Failed to read IRQ1 register\n");
> +             return;
> +     }
> +
> +     /*
> +      * If the battery is still absent, batt_presence_work is rescheduled.
> +      * Otherwise, max_charging_time is scheduled.
> +      */
> +     if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
> +             queue_delayed_work(system_power_efficient_wq,
> +                                &info->batt_presence_work,
> +                                RT9455_BATT_PRESENCE_DELAY * HZ);
> +     } else {
> +             queue_delayed_work(system_power_efficient_wq,
> +                                &info->max_charging_time_work,
> +                                RT9455_MAX_CHARGING_TIME * HZ);
> +
> +             ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
> +             if (ret) {
> +                     dev_err(dev, "Failed to read MASK1 register\n");
> +                     return;
> +             }
> +
> +             if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 1) {
> +                     ret = regmap_field_write(info->regmap_fields[F_BATABM],
> +                                              0x00);
> +                     if (ret)
> +                             dev_err(dev, "Failed to unmask BATAB interrupt\n");
> +             }
> +     }
> +}
> +
> +static const struct power_supply_desc rt9455_charger_desc = {
> +     .name                   = RT9455_DRIVER_NAME,
> +     .type                   = POWER_SUPPLY_TYPE_USB,
> +     .properties             = rt9455_charger_properties,
> +     .num_properties         = ARRAY_SIZE(rt9455_charger_properties),
> +     .get_property           = rt9455_charger_get_property,
> +     .set_property           = rt9455_charger_set_property,
> +     .property_is_writeable  = rt9455_charger_property_is_writeable,
> +};
> +
> +static int rt9455_probe(struct i2c_client *client,
> +                     const struct i2c_device_id *id)
> +{
> +     struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> +     struct device *dev = &client->dev;
> +     struct rt9455_info *info;
> +     struct power_supply_config rt9455_charger_config = {};
> +     /* mandatory device-specific data values */
> +     u32 ichrg, ieoc_percentage, voreg;
> +     /* optional device-specific data values */
> +     u32 mivr = -1, iaicr = -1;
> +     int i, ret;
> +
> +     if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
> +             dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
> +             return -ENODEV;
> +     }
> +     info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> +     if (!info)
> +             return -ENOMEM;
> +
> +     info->client = client;
> +     i2c_set_clientdata(client, info);
> +
> +     info->regmap = devm_regmap_init_i2c(client,
> +                                         &rt9455_regmap_config);
> +     if (IS_ERR(info->regmap)) {
> +             dev_err(dev, "Failed to initialize register map\n");
> +             return -EINVAL;
> +     }
> +
> +     for (i = 0; i < F_MAX_FIELDS; i++) {
> +             info->regmap_fields[i] =
> +                     devm_regmap_field_alloc(dev, info->regmap,
> +                                             rt9455_reg_fields[i]);
> +             if (IS_ERR(info->regmap_fields[i])) {
> +                     dev_err(dev,
> +                             "Failed to allocate regmap field = %d\n", i);
> +                     return PTR_ERR(info->regmap_fields[i]);
> +             }
> +     }
> +
> +     ret = rt9455_discover_charger(info, &ichrg, &ieoc_percentage,
> +                                   &voreg, &mivr, &iaicr);
> +     if (ret) {
> +             dev_err(dev, "Failed to discover charger\n");
> +             return ret;
> +     }
> +
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +     info->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
> +     if (IS_ERR_OR_NULL(info->usb_phy)) {
> +             dev_err(dev, "Failed to get USB transceiver\n");
> +     } else {
> +             info->nb.notifier_call = rt9455_usb_event;
> +             ret = usb_register_notifier(info->usb_phy, &info->nb);
> +             if (ret) {
> +                     dev_err(dev, "Failed to register USB notifier\n");
> +                     usb_put_phy(info->usb_phy);
> +             }
> +     }
> +#endif
> +
> +     INIT_DELAYED_WORK(&info->pwr_rdy_work, rt9455_pwr_rdy_work_callback);
> +     INIT_DELAYED_WORK(&info->max_charging_time_work,
> +                       rt9455_max_charging_time_work_callback);
> +     INIT_DELAYED_WORK(&info->batt_presence_work,
> +                       rt9455_batt_presence_work_callback);
> +
> +     rt9455_charger_config.of_node           = dev->of_node;
> +     rt9455_charger_config.drv_data          = info;
> +     rt9455_charger_config.supplied_to       = rt9455_charger_supplied_to;
> +     rt9455_charger_config.num_supplicants   =
> +                                     ARRAY_SIZE(rt9455_charger_supplied_to);
> +     ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +                                     rt9455_irq_handler_thread,
> +                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +                                     RT9455_DRIVER_NAME, info);
> +     if (ret < 0) {
> +             dev_err(dev, "Failed to register IRQ handler\n");
> +             return ret;
> +     }
> +
> +     ret = rt9455_hw_init(info, ichrg, ieoc_percentage, voreg, mivr, iaicr);
> +     if (ret) {
> +             dev_err(dev, "Failed to set charger to its default values\n");
> +             return ret;
> +     }
> +
> +     info->charger = power_supply_register(dev, &rt9455_charger_desc,
> +                                           &rt9455_charger_config);
> +     if (IS_ERR(info->charger)) {
> +             dev_err(dev, "Failed to register charger\n");
> +             ret = PTR_ERR(info->charger);
> +             goto put_usb_phy;
> +     }
> +
> +     return 0;
> +
> +put_usb_phy:
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +     if (!IS_ERR_OR_NULL(info->usb_phy))  {
> +             usb_unregister_notifier(info->usb_phy, &info->nb);
> +             usb_put_phy(info->usb_phy);
> +     }
> +#endif
> +     return ret;
> +}
> +
> +static int rt9455_remove(struct i2c_client *client)
> +{
> +     int ret;
> +     struct rt9455_info *info = i2c_get_clientdata(client);
> +
> +     ret = rt9455_register_reset(info);
> +     if (ret)
> +             dev_err(&info->client->dev, "Failed to set charger to its default values\n");
> +
> +#if IS_ENABLED(CONFIG_USB_PHY)
> +     if (!IS_ERR_OR_NULL(info->usb_phy)) {
> +             usb_unregister_notifier(info->usb_phy, &info->nb);
> +             usb_put_phy(info->usb_phy);
> +     }
> +#endif
> +
> +     cancel_delayed_work_sync(&info->pwr_rdy_work);
> +     cancel_delayed_work_sync(&info->max_charging_time_work);
> +     cancel_delayed_work_sync(&info->batt_presence_work);
> +
> +     power_supply_unregister(info->charger);
> +
> +     return ret;
> +}
> +
> +static const struct i2c_device_id rt9455_i2c_id_table[] = {
> +     { RT9455_DRIVER_NAME, 0 },
> +     { },
> +};
> +MODULE_DEVICE_TABLE(i2c, rt9455_i2c_id_table);
> +
> +static const struct of_device_id rt9455_of_match[] = {
> +     { .compatible = "richtek,rt9455", },
> +     { },
> +};
> +MODULE_DEVICE_TABLE(of, rt9455_of_match);
> +
> +static const struct acpi_device_id rt9455_i2c_acpi_match[] = {
> +     { "RT945500", 0 },
> +     { }
> +};
> +MODULE_DEVICE_TABLE(acpi, rt9455_i2c_acpi_match);
> +
> +static struct i2c_driver rt9455_driver = {
> +     .probe          = rt9455_probe,
> +     .remove         = rt9455_remove,
> +     .id_table       = rt9455_i2c_id_table,
> +     .driver = {
> +             .name           = RT9455_DRIVER_NAME,
> +             .of_match_table = of_match_ptr(rt9455_of_match),
> +             .acpi_match_table = ACPI_PTR(rt9455_i2c_acpi_match),
> +     },
> +};
> +module_i2c_driver(rt9455_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Anda-Maria Nicolae <anda-maria.nicolae@intel.com>");
> +MODULE_ALIAS("i2c:rt9455-charger");
> +MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
> --
> 1.7.9.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-05-04 14:12   ` Nicolae, Anda-maria
@ 2015-05-04 15:22     ` Laurentiu Palcu
  2015-05-05  5:35       ` Krzysztof Kozłowski
  0 siblings, 1 reply; 8+ messages in thread
From: Laurentiu Palcu @ 2015-05-04 15:22 UTC (permalink / raw)
  To: Nicolae, Anda-maria
  Cc: sre, dbaryshkov, robh+dt, pawel.moll, mark.rutland,
	ijc+devicetree, galak, dwmw2, linux-pm, linux-kernel, devicetree

Hi Anda,

Can you please use a decent mail client to reply to emails? It was
really hard for me to figure out which were my comments and which were
yours... And I tested 3 different clients: mutt, evolution and
outlook(the web app).

More comments inline.

laurentiu

On Mon, May 04, 2015 at 05:12:07PM +0300, Nicolae, Anda-maria wrote:
> Hi Laurentiu,
> 
> Inline are the responses to your comments.
> 
> Thanks,
> Anda
> 
> ________________________________________
> From: Palcu, Laurentiu
> Sent: Thursday, April 30, 2015 12:16 PM
> To: Nicolae, Anda-maria
> Cc: sre@kernel.org; dbaryshkov@gmail.com; robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; ijc+devicetree@hellion.org.uk; galak@codeaurora.org; dwmw2@infradead.org; linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; devicetree@vger.kernel.org
> Subject: Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
> 
> More comments inline.
> 
> laurentiu
> 
> On Wed, Apr 29, 2015 at 11:13:26PM +0300, Anda-Maria Nicolae wrote:
> > Based on the datasheet found here:
> > http://www.richtek.com/download_ds.jsp?p=RT9455
> >
> > Updates from the previous version:
> > - replaced license GPLv2 with GPL
> > - replaced vendor prefix rt with richtek
> > - replaced uppercase properties names from devicetree with lowercase separated by dash properties names
> > - replaced I/O read/write API with regmap_read/write and regmap_field_read/write
> > - used kernel multiline comment
> > - used DELAYED_WORK and scheduled the works in system_power_efficient_wq. It is high probability that the device is in suspend state while charging (i.e. the user leaves the device to charge during night) and it is needed that the scheduled works to be executed as planned.
> > - replaced struct power_supply_desc rt9455_charger_desc with static const struct power_supply_desc rt9455_charger_desc
> > - replaced if (IS_ERR_OR_NULL(info->charger)) with if (IS_ERR(info->charger))
> > - replaced {"RTK9455", 0} with { "RTK9455", 0 }
> > - removed .owner = THIS_MODULE
> The change log should go after '---'.  Otherwise it will end up in the
> commit message.
> 
> WIll do.
> 
> >
> > Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
> > ---
> >  .../devicetree/bindings/power/rt9455_charger.txt   |   43 +
> >  .../devicetree/bindings/vendor-prefixes.txt        |    1 +
> >  drivers/power/Kconfig                              |    6 +
> >  drivers/power/Makefile                             |    1 +
> >  drivers/power/rt9455_charger.c                     | 1758 ++++++++++++++++++++
> >  5 files changed, 1809 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/power/rt9455_charger.txt
> >  create mode 100644 drivers/power/rt9455_charger.c
> (...)
> 
> >
> > diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> > index 4091fb0..39f208d 100644
> > --- a/drivers/power/Kconfig
> > +++ b/drivers/power/Kconfig
> > @@ -439,6 +439,12 @@ config BATTERY_RT5033
> >         The fuelgauge calculates and determines the battery state of charge
> >         according to battery open circuit voltage.
> >
> > +config CHARGER_RT9455
> > +     tristate "Richtek RT9455 battery charger driver"
> > +     depends on I2C && GPIOLIBa
> depends on REGMAP_I2C
> 
> > +     help
> > +     Say Y to enable support for the Richtek RT9455 battery charger.
> > +
> >  source "drivers/power/reset/Kconfig"
> >
> >  endif # POWER_SUPPLY
> (...)
> 
> > diff --git a/drivers/power/rt9455_charger.c b/drivers/power/rt9455_charger.c
> > new file mode 100644
> > index 0000000..e45b0f2
> > --- /dev/null
> > +++ b/drivers/power/rt9455_charger.c
> > @@ -0,0 +1,1758 @@
> > +/*
> > + * Driver for Richtek RT9455WSC battery charger.
> > + *
> > + * Copyright (C) 2015 Intel Corporation
> > + *
> > + * 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/interrupt.h>
> > +#include <linux/delay.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_device.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/power_supply.h>
> > +#include <linux/gpio.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/i2c.h>
> > +#include <linux/acpi.h>
> > +#include <linux/usb/phy.h>
> > +#include <linux/regmap.h>
> > +
> > +#define RT9455_MANUFACTURER                  "Richtek"
> > +#define RT9455_MODEL_NAME                    "RT9455"
> > +#define RT9455_DRIVER_NAME                   "rt9455-charger"
> > +
> > +#define RT9455_IRQ_NAME                              "interrupt"
> > +
> > +#define RT9455_PWR_RDY_DELAY                 1 /* 1 second */
> > +#define RT9455_MAX_CHARGING_TIME             21600 /* 6 hrs */
> > +#define RT9455_BATT_PRESENCE_DELAY           60 /* 60 seconds */
> > +
> > +#define RT9455_CHARGE_MODE                   0x00
> > +#define RT9455_BOOST_MODE                    0x01
> > +
> > +#define RT9455_FAULT                         0x03
> > +
> > +#define RT9455_IAICR_100MA                   0x00
> > +#define RT9455_IAICR_500MA                   0x01
> > +#define RT9455_IAICR_NO_LIMIT                        0x03
> > +
> > +#define RT9455_CHARGE_DISABLE                        0x00
> > +#define RT9455_CHARGE_ENABLE                 0x01
> > +
> > +#define RT9455_PWR_FAULT                     0x00
> > +#define RT9455_PWR_GOOD                              0x01
> > +
> > +#define RT9455_REG_CTRL1                     0x00 /* CTRL1 reg address */
> > +#define RT9455_REG_CTRL1_STAT_MASK           (BIT(5) | BIT(4))
> > +#define RT9455_REG_CTRL1_BOOST_MASK          BIT(3)
> > +#define RT9455_REG_CTRL1_PWR_RDY_MASK                BIT(2)
> > +#define RT9455_REG_CTRL1_OTG_PIN_POLARITY_MASK       BIT(1)
> Since you're using regmap fields, you can get rid of the masks above.
> The same applies for the masks below (except those for the IRQ
> registers which you seem to use).
> 
> I let them there for further use, in case enhancements will be done.
Since you decided to use regmap fields, I don't see why the person doing
enhancements (whatever they might be) would use masks. They should be
consistent (I hope) with the current driver implementation and use
regmap fields.

> 
> > +
> > +#define RT9455_REG_CTRL2                     0x01 /* CTRL2 reg address */
> > +#define RT9455_REG_CTRL2_IAICR_MASK          (BIT(7) | BIT(6))
> > +#define RT9455_REG_CTRL2_TE_SHDN_EN_MASK     BIT(5)
> > +#define RT9455_REG_CTRL2_HIGHER_OCP_MASK     BIT(4)
> > +#define RT9455_REG_CTRL2_TE_MASK             BIT(3)
> > +#define RT9455_REG_CTRL2_IAICR_INT_MASK              BIT(2)
> > +#define RT9455_REG_CTRL2_HIZ_MASK            BIT(1)
> > +#define RT9455_REG_CTRL2_OPA_MODE_MASK               BIT(0)
> > +
> > +#define RT9455_REG_CTRL3                     0x02 /* CTRL3 reg address */
> > +#define RT9455_REG_CTRL3_VOREG_MASK          (BIT(7) | BIT(6) | BIT(5) | \
> > +                                              BIT(4) | BIT(3) | BIT(2))
> > +#define RT9455_REG_CTRL3_OTG_PL_MASK         BIT(1)
> > +#define RT9455_REG_CTRL3_OTG_EN_MASK         BIT(0)
> > +
> > +#define RT9455_REG_DEV_ID                    0x03 /* DEV_ID reg address */
> > +#define RT9455_REG_DEV_ID_VENDOR_ID_MASK     (BIT(7) | BIT(6) | BIT(5) | \
> > +                                              BIT(4))
> > +#define RT9455_REG_DEV_ID_CHIP_REV_MASK              (BIT(3) | BIT(2) | BIT(1) | \
> > +                                              BIT(0))
> > +
> > +#define RT9455_REG_CTRL4                     0x04 /* CTRL4 reg address */
> > +#define RT9455_REG_CTRL4_RST_MASK            BIT(7)
> > +
> > +#define RT9455_REG_CTRL5                     0x05 /* CTRL5 reg address */
> > +#define RT9455_REG_CTRL5_TMR_EN_MASK         BIT(7)
> > +#define RT9455_REG_CTRL5_MIVR_MASK           (BIT(5) | BIT(4))
> > +#define RT9455_REG_CTRL5_IPREC_MASK          (BIT(3) | BIT(2))
> > +#define RT9455_REG_CTRL5_IEOC_PERCENTAGE_MASK        (BIT(1) | BIT(0))
> > +
> > +#define RT9455_REG_CTRL6                     0x06 /* CTRL6 reg address */
> > +#define RT9455_REG_CTRL6_IAICR_SEL_MASK              BIT(7)
> > +#define RT9455_REG_CTRL6_ICHRG_MASK          (BIT(6) | BIT(5) | BIT(4))
> > +#define RT9455_REG_CTRL6_VPREC_MASK          (BIT(2) | BIT(1) | BIT(0))
> > +
> > +#define RT9455_REG_CTRL7                     0x07 /* CTRL7 reg address */
> > +#define RT9455_REG_CTRL7_BATD_EN_MASK                BIT(6)
> > +#define RT9455_REG_CTRL7_CHG_EN_MASK         BIT(4)
> > +#define RT9455_REG_CTRL7_VMREG_MASK          (BIT(3) | BIT(2) | BIT(1) | \
> > +                                              BIT(0))
> > +
> > +#define RT9455_REG_IRQ1                              0x08 /* IRQ1 reg address */
> > +#define RT9455_REG_IRQ1_TSDI_MASK            BIT(7)
> > +#define RT9455_REG_IRQ1_VINOVPI_MASK         BIT(6)
> > +#define RT9455_REG_IRQ1_BATAB_MASK           BIT(0)
> > +
> > +#define RT9455_REG_IRQ2                              0x09 /* IRQ2 reg address */
> > +#define RT9455_REG_IRQ2_CHRVPI_MASK          BIT(7)
> > +#define RT9455_REG_IRQ2_CHBATOVI_MASK                BIT(5)
> > +#define RT9455_REG_IRQ2_CHTERMI_MASK         BIT(4)
> > +#define RT9455_REG_IRQ2_CHRCHGI_MASK         BIT(3)
> > +#define RT9455_REG_IRQ2_CH32MI_MASK          BIT(2)
> > +#define RT9455_REG_IRQ2_CHTREGI_MASK         BIT(1)
> > +#define RT9455_REG_IRQ2_CHMIVRI_MASK         BIT(0)
> > +
> > +#define RT9455_REG_IRQ3                              0x0A /* IRQ3 reg address */
> > +#define RT9455_REG_IRQ3_BSTBUSOVI_MASK               BIT(7)
> > +#define RT9455_REG_IRQ3_BSTOLI_MASK          BIT(6)
> > +#define RT9455_REG_IRQ3_BSTLOWVI_MASK                BIT(5)
> > +#define RT9455_REG_IRQ3_BST32SI_MASK         BIT(3)
> > +
> > +#define RT9455_REG_MASK1                     0x0B /* MASK1 reg address */
> > +#define RT9455_REG_MASK1_TSDM_MASK           BIT(7)
> > +#define RT9455_REG_MASK1_VINOVPIM_MASK               BIT(6)
> > +#define RT9455_REG_MASK1_BATABM_MASK         BIT(0)
> > +
> > +#define RT9455_REG_MASK2                     0x0C /* MASK2 reg address */
> > +#define RT9455_REG_MASK2_CHRVPIM_MASK                BIT(7)
> > +#define RT9455_REG_MASK2_CHBATOVIM_MASK              BIT(5)
> > +#define RT9455_REG_MASK2_CHTERMIM_MASK               BIT(4)
> > +#define RT9455_REG_MASK2_CHRCHGIM_MASK               BIT(3)
> > +#define RT9455_REG_MASK2_CH32MIM_MASK                BIT(2)
> > +#define RT9455_REG_MASK2_CHTREGIM_MASK               BIT(1)
> > +#define RT9455_REG_MASK2_CHMIVRIM_MASK               BIT(0)
> > +
> > +#define RT9455_REG_MASK3                     0x0D /* MASK3 reg address */
> > +#define RT9455_REG_MASK3_BSTVINOVIM_MASK     BIT(7)
> > +#define RT9455_REG_MASK3_BSTOLIM_MASK                BIT(6)
> > +#define RT9455_REG_MASK3_BSTLOWVIM_MASK              BIT(5)
> > +#define RT9455_REG_MASK3_BST32SIM_MASK               BIT(3)
> > +
> > +enum rt9455_fields {
> > +     F_STAT, F_BOOST, F_PWR_RDY, F_OTG_PIN_POLARITY, /* CTRL1 reg fields */
> > +
> > +     F_IAICR, F_TE_SHDN_EN, F_HIGHER_OCP, F_TE, F_IAICR_INT, F_HIZ,
> > +     F_OPA_MODE, /* CTRL2 reg fields */
> > +
> > +     F_VOREG, F_OTG_PL, F_OTG_EN, /* CTRL3 reg fields */
> > +
> > +     F_VENDOR_ID, F_CHIP_REV, /* DEV_ID reg fields */
> > +
> > +     F_RST, /* CTRL4 reg fields */
> > +
> > +     F_TMR_EN, F_MIVR, F_IPREC, F_IEOC_PERCENTAGE, /* CTRL5 reg fields*/
> > +
> > +     F_IAICR_SEL, F_ICHRG, F_VPREC, /* CTRL6 reg fields */
> > +
> > +     F_BATD_EN, F_CHG_EN, F_VMREG, /* CTRL7 reg fields */
> > +
> > +     F_TSDI, F_VINOVPI, F_BATAB, /* IRQ1 reg fields */
> > +
> > +     F_CHRVPI, F_CHBATOVI, F_CHTERMI, F_CHRCHGI, F_CH32MI, F_CHTREGI,
> > +     F_CHMIVRI, /* IRQ2 reg fields */
> > +
> > +     F_BSTBUSOVI, F_BSTOLI, F_BSTLOWVI, F_BST32SI, /* IRQ3 reg fields */
> > +
> > +     F_TSDM, F_VINOVPIM, F_BATABM, /* MASK1 reg fields */
> > +
> > +     F_CHRVPIM, F_CHBATOVIM, F_CHTERMIM, F_CHRCHGIM, F_CH32MIM, F_CHTREGIM,
> > +     F_CHMIVRIM, /* MASK2 reg fields */
> > +
> > +     F_BSTVINOVIM, F_BSTOLIM, F_BSTLOWVIM, F_BST32SIM, /* MASK3 reg fields */
> > +
> > +     F_MAX_FIELDS
> > +};
> > +
> > +static const struct reg_field rt9455_reg_fields[] = {
> > +     [F_STAT]                = REG_FIELD(RT9455_REG_CTRL1, 4, 5),
> > +     [F_BOOST]               = REG_FIELD(RT9455_REG_CTRL1, 3, 3),
> > +     [F_PWR_RDY]             = REG_FIELD(RT9455_REG_CTRL1, 2, 2),
> > +     [F_OTG_PIN_POLARITY]    = REG_FIELD(RT9455_REG_CTRL1, 1, 1),
> > +
> > +     [F_IAICR]               = REG_FIELD(RT9455_REG_CTRL2, 6, 7),
> > +     [F_TE_SHDN_EN]          = REG_FIELD(RT9455_REG_CTRL2, 5, 5),
> > +     [F_HIGHER_OCP]          = REG_FIELD(RT9455_REG_CTRL2, 4, 4),
> > +     [F_TE]                  = REG_FIELD(RT9455_REG_CTRL2, 3, 3),
> > +     [F_IAICR_INT]           = REG_FIELD(RT9455_REG_CTRL2, 2, 2),
> > +     [F_HIZ]                 = REG_FIELD(RT9455_REG_CTRL2, 1, 1),
> > +     [F_OPA_MODE]            = REG_FIELD(RT9455_REG_CTRL2, 0, 0),
> > +
> > +     [F_VOREG]               = REG_FIELD(RT9455_REG_CTRL3, 2, 7),
> > +     [F_OTG_PL]              = REG_FIELD(RT9455_REG_CTRL3, 1, 1),
> > +     [F_OTG_EN]              = REG_FIELD(RT9455_REG_CTRL3, 0, 0),
> > +
> > +     [F_VENDOR_ID]           = REG_FIELD(RT9455_REG_DEV_ID, 4, 7),
> > +     [F_CHIP_REV]            = REG_FIELD(RT9455_REG_DEV_ID, 0, 3),
> > +
> > +     [F_RST]                 = REG_FIELD(RT9455_REG_CTRL4, 7, 7),
> > +
> > +     [F_TMR_EN]              = REG_FIELD(RT9455_REG_CTRL5, 7, 7),
> > +     [F_MIVR]                = REG_FIELD(RT9455_REG_CTRL5, 4, 5),
> > +     [F_IPREC]               = REG_FIELD(RT9455_REG_CTRL5, 2, 3),
> > +     [F_IEOC_PERCENTAGE]     = REG_FIELD(RT9455_REG_CTRL5, 0, 1),
> > +
> > +     [F_IAICR_SEL]           = REG_FIELD(RT9455_REG_CTRL6, 7, 7),
> > +     [F_ICHRG]               = REG_FIELD(RT9455_REG_CTRL6, 4, 6),
> > +     [F_VPREC]               = REG_FIELD(RT9455_REG_CTRL6, 0, 2),
> > +
> > +     [F_BATD_EN]             = REG_FIELD(RT9455_REG_CTRL7, 6, 6),
> > +     [F_CHG_EN]              = REG_FIELD(RT9455_REG_CTRL7, 4, 4),
> > +     [F_VMREG]               = REG_FIELD(RT9455_REG_CTRL7, 0, 3),
> > +
> > +     [F_TSDI]                = REG_FIELD(RT9455_REG_IRQ1, 7, 7),
> > +     [F_VINOVPI]             = REG_FIELD(RT9455_REG_IRQ1, 6, 6),
> > +     [F_BATAB]               = REG_FIELD(RT9455_REG_IRQ1, 0, 0),
> > +
> > +     [F_CHRVPI]              = REG_FIELD(RT9455_REG_IRQ2, 7, 7),
> > +     [F_CHBATOVI]            = REG_FIELD(RT9455_REG_IRQ2, 5, 5),
> > +     [F_CHTERMI]             = REG_FIELD(RT9455_REG_IRQ2, 4, 4),
> > +     [F_CHRCHGI]             = REG_FIELD(RT9455_REG_IRQ2, 3, 3),
> > +     [F_CH32MI]              = REG_FIELD(RT9455_REG_IRQ2, 2, 2),
> > +     [F_CHTREGI]             = REG_FIELD(RT9455_REG_IRQ2, 1, 1),
> > +     [F_CHMIVRI]             = REG_FIELD(RT9455_REG_IRQ2, 0, 0),
> > +
> > +     [F_BSTBUSOVI]           = REG_FIELD(RT9455_REG_IRQ3, 7, 7),
> > +     [F_BSTOLI]              = REG_FIELD(RT9455_REG_IRQ3, 6, 6),
> > +     [F_BSTLOWVI]            = REG_FIELD(RT9455_REG_IRQ3, 5, 5),
> > +     [F_BST32SI]             = REG_FIELD(RT9455_REG_IRQ3, 3, 3),
> I don't see any benefit in declaring fields for the IRQx registers, since
> you're not going to use them. AFAICS you're reading the entire IRQx
> registers and then use masks to retrieve the fields.
> 
> I let them there for symmetry and further use, in case enhancements
> will be done. I prefer using predefined masks instead of fields from
> struct reg_field when dealing with interrupt registers. The interrupt
> handler performs numerous checks and I believe the masks are faster
> than accessing fields from an array of reg_fields.
The same problem, the other way around. You decided to use masks for
reading the various IRQx bits, which is fine since some flags can be
cleared after reading the register the first time. However, the regmap
fields declaring IRQx flags will be never used, so they can be removed.

It makes sense, though, to leave the other fields (non-IRQ related) in
place for future use.

> 
> > +
> > +     [F_TSDM]                = REG_FIELD(RT9455_REG_MASK1, 7, 7),
> > +     [F_VINOVPIM]            = REG_FIELD(RT9455_REG_MASK1, 6, 6),
> > +     [F_BATABM]              = REG_FIELD(RT9455_REG_MASK1, 0, 0),
> > +
> > +     [F_CHRVPIM]             = REG_FIELD(RT9455_REG_MASK2, 7, 7),
> > +     [F_CHBATOVIM]           = REG_FIELD(RT9455_REG_MASK2, 5, 5),
> > +     [F_CHTERMIM]            = REG_FIELD(RT9455_REG_MASK2, 4, 4),
> > +     [F_CHRCHGIM]            = REG_FIELD(RT9455_REG_MASK2, 3, 3),
> > +     [F_CH32MIM]             = REG_FIELD(RT9455_REG_MASK2, 2, 2),
> > +     [F_CHTREGIM]            = REG_FIELD(RT9455_REG_MASK2, 1, 1),
> > +     [F_CHMIVRIM]            = REG_FIELD(RT9455_REG_MASK2, 0, 0),
> > +
> > +     [F_BSTVINOVIM]          = REG_FIELD(RT9455_REG_MASK3, 7, 7),
> > +     [F_BSTOLIM]             = REG_FIELD(RT9455_REG_MASK3, 6, 6),
> > +     [F_BSTLOWVIM]           = REG_FIELD(RT9455_REG_MASK3, 5, 5),
> > +     [F_BST32SIM]            = REG_FIELD(RT9455_REG_MASK3, 3, 3),
> > +};
> > +
> > +/*
> > + * Each array initialised below shows the possible real-world values for a
> > + * group of bits belonging to RT9455 registers. The arrays are sorted in
> > + * ascending order. The index of each real-world value represents the value
> > + * that is encoded in the group of bits belonging to RT9455 registers.
> > + */
> > +/* REG06[6:4] (ICHRG) in uAh */
> > +static const int rt9455_ichrg_values[] = {
> > +      500000,  650000,  800000,  950000, 1100000, 1250000, 1400000, 1550000
> > +};
> > +
> > +/* REG02[7:2] (VOREG) in uV */
> > +static const int rt9455_voreg_values[] = {
> > +     3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
> > +     3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
> > +     3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
> > +     3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
> > +     4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
> > +     4300000, 4330000, 4350000, 4370000, 4390000, 4410000, 4430000, 4450000,
> > +     4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000,
> > +     4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000, 4450000
> > +};
> > +
> > +/* REG07[3:0] (VMREG) in uV */
> > +static const int rt9455_vmreg_values[] = {
> > +     4200000, 4220000, 4240000, 4260000, 4280000, 4300000, 4320000, 4340000,
> > +     4360000, 4380000, 4400000, 4430000, 4450000, 4450000, 4450000, 4450000
> > +};
> > +
> > +/* REG05[5:4] (IEOC_PERCENTAGE) */
> > +static const int rt9455_ieoc_percentage_values[] = {
> > +     10, 30, 20, 30
> > +};
> > +
> > +/* REG05[1:0] (MIVR) in uV */
> > +static const int rt9455_mivr_values[] = {
> > +     4000000, 4250000, 4500000, 5000000
> > +};
> > +
> > +/* REG05[1:0] (IAICR) in uA */
> > +static const int rt9455_iaicr_values[] = {
> > +     100000, 500000, 1000000, 2000000
> > +};
> > +
> > +struct rt9455_info {
> > +     struct i2c_client               *client;
> > +     struct regmap                   *regmap;
> > +     struct regmap_field             *regmap_fields[F_MAX_FIELDS];
> > +     struct power_supply             *charger;
> > +#if IS_ENABLED(CONFIG_USB_PHY)
> > +     struct usb_phy                  *usb_phy;
> > +     struct notifier_block           nb;
> > +#endif
> > +     struct gpio_desc                *gpiod_irq;
> > +     unsigned int                    gpio_irq;
> > +     struct delayed_work             pwr_rdy_work;
> > +     struct delayed_work             max_charging_time_work;
> > +     struct delayed_work             batt_presence_work;
> > +};
> > +
> > +static const struct regmap_config rt9455_regmap_config = {
> > +     .reg_bits = 8,
> > +     .val_bits = 8,
> > +     .max_register = RT9455_REG_MASK3,
> > +};
> Do you need all chip's registers to be volatile? Can we cache any of
> them so we don't make unnecessary read operations on the I2C bus?
> 
> I can cache reg 0x03 and reg 0x05. 
> 
> (...)
> > +
> > +static int rt9455_charger_get_status(struct rt9455_info *info,
> > +                                  union power_supply_propval *val)
> > +{
> > +     unsigned int v;
> > +     int ret;
> > +
> > +     ret = regmap_field_read(info->regmap_fields[F_STAT], &v);
> > +     if (ret) {
> > +             dev_err(&info->client->dev, "Failed to read STAT bits\n");
> > +             return ret;
> > +     }
> > +
> > +     switch (v) {
> > +     case 0:
> > +             val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > +     break;
> > +     case 1:
> > +             val->intval = POWER_SUPPLY_STATUS_CHARGING;
> > +     break;
> > +     case 2:
> > +             val->intval = POWER_SUPPLY_STATUS_FULL;
> > +     break;
> > +     default:
> > +             val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
> > +     break;
> > +     }
> Please indent the breaks to conform to kernel coding style.
> 
> Will do.
> 
> Also, just an idea, maybe you should also return
> POWER_SUPPLY_STATUS_DISCHARGING when the power is not plugged in
> because, technically, if PWR_RDY=0 the battery will discharge...
> 
> There are cases in which power source can be plugged in (PWR_RDY bit
> is 1) and the battery is not being charged.
You already return POWER_SUPPLY_STATUS_NOT_CHARGING in this case.

> These are: the charge bit
> is cleared (set to 0), or the battery is already full (in this case,
> STAT bits value is 2).  Also, when the battery is not connected to the
> charger, STAT bits value is either 3 or 0. So if I return
> POWER_SUPPLY_STATUS_DISCHARGING, I also have to check whether the
> battery is connected or not. In addition to this, I also believe that
> POWER_SUPPLY_STATUS_DISCHARGING should be returned when the charger is
> neither in sleep mode, nor in high impedance mode (so there is
> additional check to do). In both modes, the charger tries to operate
> with minimum current from the battery, to prevent battery drain. So
> theoretically, the current drawn by the charger from the battery can
> be considered as negligible.  This is why I prefer to return
> POWER_SUPPLY_STATUS_NOT_CHARGING.
All you have to do is check PWR_RDY. If it's 0, then your battery will
be discharging. Is it not? You don't have to check the existence of the
battery because, technically, if you have no battery connected and the
charger is *not* plugged in, that means only one thing: your device is
not powered on.

> 
> (...)
> 
> > +
> > +static int rt9455_charger_get_voltage_max(struct rt9455_info *info,
> > +                                       union power_supply_propval *val)
> > +{
> > +     int idx = ARRAY_SIZE(rt9455_voreg_values) - 1;
> rt9455_vmreg_values?
> 
> > +
> > +     val->intval = rt9455_voreg_values[idx];
> ditto.
> 
> Since I set TE and TE_SHDN_EN, the charging terminates if the charge
> current is below termination current (IEOC) in constant voltage mode.
> From my experiments, charging is done when battery voltage is almost
> equal to VOREG. Therefore, the battery voltage never reaches VMREG in
> this configuration. This is why I use maximum VOREG value instead of
> VMREG. If I do not set TE or TE_SHDN_EN bit, the charger will not
> trigger any interrupt when charging is done.
Both rt9455_voreg_values and rt9455_vmreg_values have the same maximum
value. Your function will return the right thing, but it's confusing.
Please use rt9455_vmreg_values here.

> 
> > +
> > +     return 0;
> > +}
> (...)
> > +
> > +static int rt9455_charger_get_property(struct power_supply *psy,
> > +                                    enum power_supply_property psp,
> > +                                    union power_supply_propval *val)
> > +{
> > +     struct rt9455_info *info = power_supply_get_drvdata(psy);
> > +
> > +     switch (psp) {
> > +     case POWER_SUPPLY_PROP_STATUS:
> > +             return rt9455_charger_get_status(info, val);
> > +     case POWER_SUPPLY_PROP_HEALTH:
> > +             return rt9455_charger_get_health(info, val);
> > +     case POWER_SUPPLY_PROP_PRESENT:
> > +             return rt9455_charger_get_battery_presence(info, val);
> > +     case POWER_SUPPLY_PROP_ONLINE:
> > +             return rt9455_charger_get_online(info, val);
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> > +             return rt9455_charger_get_current(info, val);
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
> > +             return rt9455_charger_get_current_max(info, val);
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> > +             return rt9455_charger_get_voltage(info, val);
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> > +             return rt9455_charger_get_voltage_max(info, val);
> > +     case POWER_SUPPLY_PROP_SCOPE:
> > +             val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
> > +             return 0;
> > +     case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
> > +             return rt9455_charger_get_term_current(info, val);
> > +     case POWER_SUPPLY_PROP_MODEL_NAME:
> > +             val->strval = RT9455_MODEL_NAME;
> > +             return 0;
> > +     case POWER_SUPPLY_PROP_MANUFACTURER:
> > +             val->strval = RT9455_MANUFACTURER;
> > +             return 0;
> > +     default:
> > +             return -ENODATA;
> > +     }
> > +}
> > +
> (...)
> > +
> > +static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
> > +                                       const union power_supply_propval *val)
> > +{
> > +     return rt9455_set_field_val(info, F_VMREG,
> > +                                 rt9455_vmreg_values,
> > +                                 ARRAY_SIZE(rt9455_vmreg_values),
> > +                                 val->intval);
> > +}
> > +
> > +static int rt9455_charger_set_property(struct power_supply *psy,
> > +                                    enum power_supply_property psp,
> > +                                    const union power_supply_propval *val)
> > +{
> > +     struct rt9455_info *info = power_supply_get_drvdata(psy);
> > +
> > +     switch (psp) {
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> > +             return rt9455_charger_set_current(info, val);
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
> > +             return rt9455_charger_set_voltage(info, val);
> Personally, I'm against having these properties writable. A user might
> play with the charging voltage or current and then complain that the
> battery does not charge at all, or it takes ages to charge. I'd leave
> these to be set by manufacturer through DT/ACPI. But, it's just an
> opinion.
> 
> If the user really wants to damage his/her battery, he/she can charge
> the values from DT/ACPI. Also, numerous charger drivers expose these
> properties as writable.  I prefer leaving them as they are.
This is debatable. I agree that regular users don't, usually, change the
DT/ACPI tables or roam through sysfs to play with various parameters.

Perhaps more experienced people can comment on this.

> 
> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
> > +             return rt9455_charger_set_voltage_max(info, val);
> You set the max voltage here, but rt9455_charger_get_voltage_max()
> returns the maximum allowed value. Shouldn't it return the value you
> just set here?
> 
> Max VOREG value equals max VMREG value (4.45V). I agree that it is
> confusing and I will use VOREG in both places.
You misunderstood me. You actually set a value here, other than 4.45V.
It would make more sense for rt9455_charger_get_voltage_max() to return
this value, not 4.45V.

> 
> > +     default:
> > +             return -EINVAL;
> > +     }
> > +}
> > +
> (...)
> 
> > +
> > +static int rt9455_usb_event_none(struct rt9455_info *info,
> > +                              u8 opa_mode, u8 iaicr)
> > +{
> > +     struct device *dev = &info->client->dev;
> > +     int ret;
> > +
> > +     if (opa_mode == RT9455_BOOST_MODE) {
> > +             /*
> > +              * If the charger is in boost mode, and it has received
> > +              * USB_EVENT_NONE, this means the consumer device powered by the
> > +              * charger is not connected anymore.
> > +              * In this case, the charger goes into charge mode.
> > +              */
> > +             dev_dbg(dev, "USB_EVENT_NONE received, therefore the charger goes into charge mode\n");
> Do you really need both the comment and the dev_dbg? The latter seems
> explanatory enough, even though I'd shorten it a little: "USB_EVENT_NONE
> received, enter charge mode". The same goes for the next 4 functions.
> 
> Yes. The comment explains the purpose of the function, while the
> dev_dbg can be activated to be shown in dmesg. Dev_dbg can be
> activated to check if the driver really enters in the respective
> function, in case a bug/issue occurs.
I didn't say dev_dbg is useless here. I just said that the comment is
redundant. Oh well, I can live with that...

> 
> > +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> > +                                      RT9455_CHARGE_MODE);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set charger in charge mode\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     dev_dbg(dev, "USB_EVENT_NONE received, therefore IAICR is set to its minimum value\n");
> > +     if (iaicr != RT9455_IAICR_100MA) {
> > +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> > +                                      RT9455_IAICR_100MA);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set IAICR value\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     return NOTIFY_OK;
> > +}
> > +
> > +static int rt9455_usb_event_vbus(struct rt9455_info *info,
> > +                              u8 opa_mode, u8 iaicr)
> > +{
> > +     struct device *dev = &info->client->dev;
> > +     int ret;
> > +
> > +     if (opa_mode == RT9455_BOOST_MODE) {
> > +             /*
> > +              * If the charger is in boost mode, and it has received
> > +              * USB_EVENT_VBUS, this means the consumer device powered by the
> > +              * charger is not connected anymore.
> > +              * In this case, the charger goes into charge mode.
> > +              */
> > +             dev_dbg(dev, "USB_EVENT_VBUS received, therefore the charger goes into charge mode\n");
> > +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> > +                                      RT9455_CHARGE_MODE);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set charger in charge mode\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     dev_dbg(dev, "USB_EVENT_VBUS received, therefore IAICR is set to 500 mA\n");
> > +     if (iaicr != RT9455_IAICR_500MA) {
> > +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> > +                                      RT9455_IAICR_500MA);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set IAICR value\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     return NOTIFY_OK;
> > +}
> > +
> > +static int rt9455_usb_event_id(struct rt9455_info *info,
> > +                            u8 opa_mode, u8 iaicr)
> > +{
> > +     struct device *dev = &info->client->dev;
> > +     int ret;
> > +
> > +     if (opa_mode == RT9455_CHARGE_MODE) {
> > +             /*
> > +              * If the charger is in charge mode, and it has received
> > +              * USB_EVENT_ID, this means the consumer device powered by the
> > +              * charger is not connected anymore.
> > +              * In this case, the charger goes into charge mode.
> s/goes into charge mode/goes into boost mode/
> 
> Will correct comment.
> 
> > +              */
> > +             dev_dbg(dev, "USB_EVENT_ID received, therefore the charger goes into boost mode\n");
> > +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> > +                                      RT9455_BOOST_MODE);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set charger in boost mode\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     dev_dbg(dev, "USB_EVENT_ID received, therefore IAICR is set to its minimum value\n");
> > +     if (iaicr != RT9455_IAICR_100MA) {
> > +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> > +                                      RT9455_IAICR_100MA);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set IAICR value\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     return NOTIFY_OK;
> > +}
> > +
> > +static int rt9455_usb_event_charger(struct rt9455_info *info,
> > +                                 u8 opa_mode, u8 iaicr)
> > +{
> > +     struct device *dev = &info->client->dev;
> > +     int ret;
> > +
> > +     if (opa_mode == RT9455_BOOST_MODE) {
> > +             /*
> > +              * If the charger is in boost mode, and it has received
> > +              * USB_EVENT_CHARGER, this means the consumer device powered by
> > +              * the charger is not connected anymore.
> > +              * In this case, the charger goes into charge mode.
> > +              */
> > +             dev_dbg(dev, "USB_EVENT_CHARGER received, therefore the charger goes into charge mode\n");
> > +             ret = regmap_field_write(info->regmap_fields[F_OPA_MODE],
> > +                                      RT9455_CHARGE_MODE);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set charger in charge mode\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     dev_dbg(dev, "USB_EVENT_CHARGER received, therefore IAICR is set to no current limit\n");
> > +     if (iaicr != RT9455_IAICR_NO_LIMIT) {
> > +             ret = regmap_field_write(info->regmap_fields[F_IAICR],
> > +                                      RT9455_IAICR_NO_LIMIT);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to set IAICR value\n");
> > +                     return NOTIFY_DONE;
> > +             }
> > +     }
> > +
> > +     return NOTIFY_OK;
> > +}
> > +
> (...)
> > +
> > +static void rt9455_max_charging_time_work_callback(struct work_struct *work)
> > +{
> > +     struct rt9455_info *info = container_of(work, struct rt9455_info,
> > +                                             max_charging_time_work.work);
> > +     struct device *dev = &info->client->dev;
> > +     int ret;
> > +
> > +     dev_err(dev, "Battery has been charging for at least 6 hours and is not yet fully charged. Battery is dead, therefore charging is disabled.\n");
> If battery is not charged in 6 hours may not necessarily mean that it's
> dead... Perhaps a low charge current was set. So, why not shorten this
> to just: "Safety timer expired, disable charging."
> 
> I prefer leaving it as it is. Safety timer refers to something else;
> RT9455 charger has a built-in safety timer which disables charging
> when no I2C read/write is done within 32 mins. The user may believe
> that this built-in timer expired, Also, when the charger is connected
> to a power source, minimum value for input current is 500 mA while
> minimum value for output current is also 500 mA. I believe this should
> be enough to charge a good battery in 6 hrs.
Fair enough.

> 
> > +     ret = regmap_field_write(info->regmap_fields[F_CHG_EN],
> > +                              RT9455_CHARGE_DISABLE);
> > +     if (ret)
> > +             dev_err(dev, "Failed to disable charging\n");
> > +}
> > +
> > +static void rt9455_batt_presence_work_callback(struct work_struct *work)
> > +{
> > +     struct rt9455_info *info = container_of(work, struct rt9455_info,
> > +                                             batt_presence_work.work);
> > +     struct device *dev = &info->client->dev;
> > +     unsigned int irq1, mask1;
> > +     int ret;
> > +
> > +     ret = regmap_read(info->regmap, RT9455_REG_IRQ1, &irq1);
> > +     if (ret) {
> > +             dev_err(dev, "Failed to read IRQ1 register\n");
> > +             return;
> > +     }
> > +
> > +     /*
> > +      * If the battery is still absent, batt_presence_work is rescheduled.
> > +      * Otherwise, max_charging_time is scheduled.
> > +      */
> > +     if (irq1 & RT9455_REG_IRQ1_BATAB_MASK) {
> > +             queue_delayed_work(system_power_efficient_wq,
> > +                                &info->batt_presence_work,
> > +                                RT9455_BATT_PRESENCE_DELAY * HZ);
> > +     } else {
> > +             queue_delayed_work(system_power_efficient_wq,
> > +                                &info->max_charging_time_work,
> > +                                RT9455_MAX_CHARGING_TIME * HZ);
> > +
> > +             ret = regmap_read(info->regmap, RT9455_REG_MASK1, &mask1);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to read MASK1 register\n");
> > +                     return;
> > +             }
> > +
> > +             if ((mask1 & RT9455_REG_MASK1_BATABM_MASK) == 1) {
> > +                     ret = regmap_field_write(info->regmap_fields[F_BATABM],
> > +                                              0x00);
> > +                     if (ret)
> > +                             dev_err(dev, "Failed to unmask BATAB interrupt\n");
> > +             }
> > +     }
> > +}
> > +
> > +static const struct power_supply_desc rt9455_charger_desc = {
> > +     .name                   = RT9455_DRIVER_NAME,
> > +     .type                   = POWER_SUPPLY_TYPE_USB,
> > +     .properties             = rt9455_charger_properties,
> > +     .num_properties         = ARRAY_SIZE(rt9455_charger_properties),
> > +     .get_property           = rt9455_charger_get_property,
> > +     .set_property           = rt9455_charger_set_property,
> > +     .property_is_writeable  = rt9455_charger_property_is_writeable,
> > +};
> > +
> > +static int rt9455_probe(struct i2c_client *client,
> > +                     const struct i2c_device_id *id)
> > +{
> > +     struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
> > +     struct device *dev = &client->dev;
> > +     struct rt9455_info *info;
> > +     struct power_supply_config rt9455_charger_config = {};
> > +     /* mandatory device-specific data values */
> > +     u32 ichrg, ieoc_percentage, voreg;
> > +     /* optional device-specific data values */
> > +     u32 mivr = -1, iaicr = -1;
> > +     int i, ret;
> > +
> > +     if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
> > +             dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
> > +             return -ENODEV;
> > +     }
> > +     info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> > +     if (!info)
> > +             return -ENOMEM;
> > +
> > +     info->client = client;
> > +     i2c_set_clientdata(client, info);
> > +
> > +     info->regmap = devm_regmap_init_i2c(client,
> > +                                         &rt9455_regmap_config);
> > +     if (IS_ERR(info->regmap)) {
> > +             dev_err(dev, "Failed to initialize register map\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     for (i = 0; i < F_MAX_FIELDS; i++) {
> > +             info->regmap_fields[i] =
> > +                     devm_regmap_field_alloc(dev, info->regmap,
> > +                                             rt9455_reg_fields[i]);
> > +             if (IS_ERR(info->regmap_fields[i])) {
> > +                     dev_err(dev,
> > +                             "Failed to allocate regmap field = %d\n", i);
> > +                     return PTR_ERR(info->regmap_fields[i]);
> > +             }
> > +     }
> > +
> > +     ret = rt9455_discover_charger(info, &ichrg, &ieoc_percentage,
> > +                                   &voreg, &mivr, &iaicr);
> > +     if (ret) {
> > +             dev_err(dev, "Failed to discover charger\n");
> > +             return ret;
> > +     }
> > +
> > +#if IS_ENABLED(CONFIG_USB_PHY)
> > +     info->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
> > +     if (IS_ERR_OR_NULL(info->usb_phy)) {
> > +             dev_err(dev, "Failed to get USB transceiver\n");
> > +     } else {
> > +             info->nb.notifier_call = rt9455_usb_event;
> > +             ret = usb_register_notifier(info->usb_phy, &info->nb);
> > +             if (ret) {
> > +                     dev_err(dev, "Failed to register USB notifier\n");
> > +                     usb_put_phy(info->usb_phy);
> > +             }
> > +     }
> > +#endif
> > +
> > +     INIT_DELAYED_WORK(&info->pwr_rdy_work, rt9455_pwr_rdy_work_callback);
> > +     INIT_DELAYED_WORK(&info->max_charging_time_work,
> > +                       rt9455_max_charging_time_work_callback);
> > +     INIT_DELAYED_WORK(&info->batt_presence_work,
> > +                       rt9455_batt_presence_work_callback);
> > +
> > +     rt9455_charger_config.of_node           = dev->of_node;
> > +     rt9455_charger_config.drv_data          = info;
> > +     rt9455_charger_config.supplied_to       = rt9455_charger_supplied_to;
> > +     rt9455_charger_config.num_supplicants   =
> > +                                     ARRAY_SIZE(rt9455_charger_supplied_to);
> > +     ret = devm_request_threaded_irq(dev, client->irq, NULL,
> > +                                     rt9455_irq_handler_thread,
> > +                                     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> > +                                     RT9455_DRIVER_NAME, info);
> > +     if (ret < 0) {
> > +             dev_err(dev, "Failed to register IRQ handler\n");
> > +             return ret;
> > +     }
> > +
> > +     ret = rt9455_hw_init(info, ichrg, ieoc_percentage, voreg, mivr, iaicr);
> > +     if (ret) {
> > +             dev_err(dev, "Failed to set charger to its default values\n");
> > +             return ret;
> > +     }
> > +
> > +     info->charger = power_supply_register(dev, &rt9455_charger_desc,
> > +                                           &rt9455_charger_config);
> > +     if (IS_ERR(info->charger)) {
> > +             dev_err(dev, "Failed to register charger\n");
> > +             ret = PTR_ERR(info->charger);
> > +             goto put_usb_phy;
> > +     }
> > +
> > +     return 0;
> > +
> > +put_usb_phy:
> > +#if IS_ENABLED(CONFIG_USB_PHY)
> > +     if (!IS_ERR_OR_NULL(info->usb_phy))  {
> > +             usb_unregister_notifier(info->usb_phy, &info->nb);
> > +             usb_put_phy(info->usb_phy);
> > +     }
> > +#endif
> > +     return ret;
> > +}
> > +
> > +static int rt9455_remove(struct i2c_client *client)
> > +{
> > +     int ret;
> > +     struct rt9455_info *info = i2c_get_clientdata(client);
> > +
> > +     ret = rt9455_register_reset(info);
> > +     if (ret)
> > +             dev_err(&info->client->dev, "Failed to set charger to its default values\n");
> > +
> > +#if IS_ENABLED(CONFIG_USB_PHY)
> > +     if (!IS_ERR_OR_NULL(info->usb_phy)) {
> > +             usb_unregister_notifier(info->usb_phy, &info->nb);
> > +             usb_put_phy(info->usb_phy);
> > +     }
> > +#endif
> > +
> > +     cancel_delayed_work_sync(&info->pwr_rdy_work);
> > +     cancel_delayed_work_sync(&info->max_charging_time_work);
> > +     cancel_delayed_work_sync(&info->batt_presence_work);
> > +
> > +     power_supply_unregister(info->charger);
> > +
> > +     return ret;
> > +}
> > +
> > +static const struct i2c_device_id rt9455_i2c_id_table[] = {
> > +     { RT9455_DRIVER_NAME, 0 },
> > +     { },
> > +};
> > +MODULE_DEVICE_TABLE(i2c, rt9455_i2c_id_table);
> > +
> > +static const struct of_device_id rt9455_of_match[] = {
> > +     { .compatible = "richtek,rt9455", },
> > +     { },
> > +};
> > +MODULE_DEVICE_TABLE(of, rt9455_of_match);
> > +
> > +static const struct acpi_device_id rt9455_i2c_acpi_match[] = {
> > +     { "RT945500", 0 },
> > +     { }
> > +};
> > +MODULE_DEVICE_TABLE(acpi, rt9455_i2c_acpi_match);
> > +
> > +static struct i2c_driver rt9455_driver = {
> > +     .probe          = rt9455_probe,
> > +     .remove         = rt9455_remove,
> > +     .id_table       = rt9455_i2c_id_table,
> > +     .driver = {
> > +             .name           = RT9455_DRIVER_NAME,
> > +             .of_match_table = of_match_ptr(rt9455_of_match),
> > +             .acpi_match_table = ACPI_PTR(rt9455_i2c_acpi_match),
> > +     },
> > +};
> > +module_i2c_driver(rt9455_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_AUTHOR("Anda-Maria Nicolae <anda-maria.nicolae@intel.com>");
> > +MODULE_ALIAS("i2c:rt9455-charger");
> > +MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
> > --
> > 1.7.9.5
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-pm" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger
  2015-05-04 15:22     ` Laurentiu Palcu
@ 2015-05-05  5:35       ` Krzysztof Kozłowski
  0 siblings, 0 replies; 8+ messages in thread
From: Krzysztof Kozłowski @ 2015-05-05  5:35 UTC (permalink / raw)
  To: Laurentiu Palcu
  Cc: Nicolae, Anda-maria, sre, dbaryshkov, robh+dt, pawel.moll,
	mark.rutland, ijc+devicetree, galak, dwmw2, linux-pm,
	linux-kernel, devicetree

2015-05-05 0:22 GMT+09:00 Laurentiu Palcu <laurentiu.palcu@intel.com>:
> Hi Anda,
>
> Can you please use a decent mail client to reply to emails? It was
> really hard for me to figure out which were my comments and which were
> yours... And I tested 3 different clients: mutt, evolution and
> outlook(the web app).
>
> More comments inline.
>
> laurentiu
>
> On Mon, May 04, 2015 at 05:12:07PM +0300, Nicolae, Anda-maria wrote:

(...)

>> > +
>> (...)
>> > +
>> > +static int rt9455_charger_set_voltage_max(struct rt9455_info *info,
>> > +                                       const union power_supply_propval *val)
>> > +{
>> > +     return rt9455_set_field_val(info, F_VMREG,
>> > +                                 rt9455_vmreg_values,
>> > +                                 ARRAY_SIZE(rt9455_vmreg_values),
>> > +                                 val->intval);
>> > +}
>> > +
>> > +static int rt9455_charger_set_property(struct power_supply *psy,
>> > +                                    enum power_supply_property psp,
>> > +                                    const union power_supply_propval *val)
>> > +{
>> > +     struct rt9455_info *info = power_supply_get_drvdata(psy);
>> > +
>> > +     switch (psp) {
>> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> > +             return rt9455_charger_set_current(info, val);
>> > +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
>> > +             return rt9455_charger_set_voltage(info, val);
>> Personally, I'm against having these properties writable. A user might
>> play with the charging voltage or current and then complain that the
>> battery does not charge at all, or it takes ages to charge. I'd leave
>> these to be set by manufacturer through DT/ACPI. But, it's just an
>> opinion.
>>
>> If the user really wants to damage his/her battery, he/she can charge
>> the values from DT/ACPI.

No, the end user does not change the DT/ACPI. It just runs some Linux
distro or Android phone. The userspace does not change DT either. So
allowing userspace to set this through regular sysfs API is rather
exceptional.

>> Also, numerous charger drivers expose these
>> properties as writable.  I prefer leaving them as they are.

I found only one mainline driver which exposes these properties as
writeable: bq24190_charger.c. Others do not. Many other drivers uses
power supply class only as a reading interface. The charger is
actually operated through respective regulator driver.

Best regards,
Krzysztof

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2015-05-05  5:37 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-04-29 20:13 [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger Anda-Maria Nicolae
2015-04-29 20:13 ` Anda-Maria Nicolae
2015-04-30  7:53 ` Krzysztof Kozlowski
2015-05-04 12:48   ` Nicolae, Anda-maria
2015-04-30  9:16 ` Laurentiu Palcu
2015-05-04 14:12   ` Nicolae, Anda-maria
2015-05-04 15:22     ` Laurentiu Palcu
2015-05-05  5:35       ` Krzysztof Kozłowski

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