RE: [PATCHv2] power_supply: Add support for Richtek rt9455 battery charger

From: Nicolae, Anda-maria
Date: Mon May 04 2015 - 10:12:24 EST


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@xxxxxxxxxx; dbaryshkov@xxxxxxxxx; robh+dt@xxxxxxxxxx; pawel.moll@xxxxxxx; mark.rutland@xxxxxxx; ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx; dwmw2@xxxxxxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx
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@xxxxxxxxx>
> ---
> .../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@xxxxxxxxx>");
> +MODULE_ALIAS("i2c:rt9455-charger");
> +MODULE_DESCRIPTION("Richtek RT9455 Charger Driver");
> --
> 1.7.9.5
>
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