diff mbox series

[v3] power/supply: Add ltc4162-l-charger

Message ID 20201102092131.16604-1-mike.looijmans@topic.nl
State New
Headers show
Series [v3] power/supply: Add ltc4162-l-charger | expand

Commit Message

Mike Looijmans Nov. 2, 2020, 9:21 a.m. UTC
Add support for the LTC4162-L Li-Ion battery charger. The driver allows
reading back telemetry and to set some charging options like the input
current limit.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
v2: Use microohm units instead of milliohm
    Add interrupt support using smbalert
    Support obtaining cell-count from devicetree
v3: Fix overflows in calculations involving resistor values
resent, mail bounced

 drivers/power/supply/Kconfig             |   8 +
 drivers/power/supply/Makefile            |   1 +
 drivers/power/supply/ltc4162-l-charger.c | 898 +++++++++++++++++++++++
 3 files changed, 907 insertions(+)
 create mode 100644 drivers/power/supply/ltc4162-l-charger.c

Comments

Mike Looijmans Dec. 3, 2020, 4:01 p.m. UTC | #1
Gentle ping, haven't seen any response...


Met vriendelijke groet / kind regards,

Mike Looijmans
System Expert


TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands

T: +31 (0) 499 33 69 69
E: mike.looijmans@topicproducts.com
W: www.topicproducts.com

Please consider the environment before printing this e-mail
On 02-11-2020 10:21, Mike Looijmans wrote:
> Add support for the LTC4162-L Li-Ion battery charger. The driver allows

> reading back telemetry and to set some charging options like the input

> current limit.

>

> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>

> ---

> v2: Use microohm units instead of milliohm

>      Add interrupt support using smbalert

>      Support obtaining cell-count from devicetree

> v3: Fix overflows in calculations involving resistor values

> resent, mail bounced

>

>   drivers/power/supply/Kconfig             |   8 +

>   drivers/power/supply/Makefile            |   1 +

>   drivers/power/supply/ltc4162-l-charger.c | 898 +++++++++++++++++++++++

>   3 files changed, 907 insertions(+)

>   create mode 100644 drivers/power/supply/ltc4162-l-charger.c

>

> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig

> index eec646c568b7..23000976cb42 100644

> --- a/drivers/power/supply/Kconfig

> +++ b/drivers/power/supply/Kconfig

> @@ -513,6 +513,14 @@ config CHARGER_LT3651

>   	  Say Y to include support for the Analog Devices (Linear Technology)

>   	  LT3651 battery charger which reports its status via GPIO lines.

>   

> +config CHARGER_LTC4162L

> +	tristate "LTC4162-L charger"

> +	depends on I2C

> +	select REGMAP_I2C

> +	help

> +	  Say Y to include support for the Analog Devices (Linear Technology)

> +	  LTC4162-L battery charger connected to I2C.

> +

>   config CHARGER_MAX14577

>   	tristate "Maxim MAX14577/77836 battery charger driver"

>   	depends on MFD_MAX14577

> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile

> index dd4b86318cd9..17b1cf921c44 100644

> --- a/drivers/power/supply/Makefile

> +++ b/drivers/power/supply/Makefile

> @@ -70,6 +70,7 @@ obj-$(CONFIG_CHARGER_LP8788)	+= lp8788-charger.o

>   obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o

>   obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o

>   obj-$(CONFIG_CHARGER_LT3651)	+= lt3651-charger.o

> +obj-$(CONFIG_CHARGER_LTC4162L)	+= ltc4162-l-charger.o

>   obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o

>   obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o

>   obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o

> diff --git a/drivers/power/supply/ltc4162-l-charger.c b/drivers/power/supply/ltc4162-l-charger.c

> new file mode 100644

> index 000000000000..b2f666113125

> --- /dev/null

> +++ b/drivers/power/supply/ltc4162-l-charger.c

> @@ -0,0 +1,898 @@

> +// SPDX-License-Identifier: GPL-2.0-or-later

> +/*

> + *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.

> + *  Copyright (C) 2020, Topic Embedded Products

> + */

> +

> +#include <linux/module.h>

> +#include <linux/delay.h>

> +#include <linux/of_device.h>

> +#include <linux/pm_runtime.h>

> +#include <linux/power_supply.h>

> +#include <linux/i2c.h>

> +#include <linux/regmap.h>

> +

> +/* Registers (names based on what datasheet uses) */

> +#define LTC4162L_EN_LIMIT_ALERTS_REG		0x0D

> +#define LTC4162L_EN_CHARGER_STATE_ALERTS_REG	0x0E

> +#define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG	0x0F

> +#define LTC4162L_CONFIG_BITS_REG		0x14

> +#define LTC4162L_IIN_LIMIT_TARGET		0x15

> +#define LTC4162L_ARM_SHIP_MODE			0x19

> +#define LTC4162L_CHARGE_CURRENT_SETTING		0X1A

> +#define LTC4162L_VCHARGE_SETTING		0X1B

> +#define LTC4162L_C_OVER_X_THRESHOLD		0x1C

> +#define LTC4162L_MAX_CV_TIME			0X1D

> +#define LTC4162L_MAX_CHARGE_TIME		0X1E

> +#define LTC4162L_CHARGER_CONFIG_BITS		0x29

> +#define LTC4162L_CHARGER_STATE			0x34

> +#define LTC4162L_CHARGE_STATUS			0x35

> +#define LTC4162L_LIMIT_ALERTS_REG		0x36

> +#define LTC4162L_CHARGER_STATE_ALERTS_REG	0x37

> +#define LTC4162L_CHARGE_STATUS_ALERTS_REG	0x38

> +#define LTC4162L_SYSTEM_STATUS_REG		0x39

> +#define LTC4162L_VBAT				0x3A

> +#define LTC4162L_VIN				0x3B

> +#define LTC4162L_VOUT				0x3C

> +#define LTC4162L_IBAT				0x3D

> +#define LTC4162L_IIN				0x3E

> +#define LTC4162L_DIE_TEMPERATURE		0x3F

> +#define LTC4162L_THERMISTOR_VOLTAGE		0x40

> +#define LTC4162L_BSR				0x41

> +#define LTC4162L_JEITA_REGION			0x42

> +#define LTC4162L_CHEM_CELLS_REG			0x43

> +#define LTC4162L_ICHARGE_DAC			0x44

> +#define LTC4162L_VCHARGE_DAC			0x45

> +#define LTC4162L_IIN_LIMIT_DAC			0x46

> +#define LTC4162L_VBAT_FILT			0x47

> +#define LTC4162L_INPUT_UNDERVOLTAGE_DAC		0x4B

> +

> +/* Enumeration as in datasheet. Individual bits are mutually exclusive. */

> +enum ltc4162l_state {

> +	battery_detection = 2048,

> +	charger_suspended = 256,

> +	precharge = 128,   /* trickle on low bat voltage */

> +	cc_cv_charge = 64, /* normal charge */

> +	ntc_pause = 32,

> +	timer_term = 16,

> +	c_over_x_term = 8, /* battery is full */

> +	max_charge_time_fault = 4,

> +	bat_missing_fault = 2,

> +	bat_short_fault = 1

> +};

> +

> +/* Individual bits are mutually exclusive. Only active in charging states.*/

> +enum ltc4162l_charge_status {

> +	ilim_reg_active = 32,

> +	thermal_reg_active = 16,

> +	vin_uvcl_active = 8,

> +	iin_limit_active = 4,

> +	constant_current = 2,

> +	constant_voltage = 1,

> +	charger_off = 0

> +};

> +

> +/* Magic number to write to ARM_SHIP_MODE register */

> +#define LTC4162L_ARM_SHIP_MODE_MAGIC 21325

> +

> +struct ltc4162l_info {

> +	struct i2c_client	*client;

> +	struct regmap		*regmap;

> +	struct power_supply	*charger;

> +	u32 rsnsb;	/* Series resistor that sets charge current, microOhm */

> +	u32 rsnsi;	/* Series resistor to measure input current, microOhm */

> +	u8 cell_count;	/* Number of connected cells, 0 while unknown */

> +};

> +

> +static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)

> +{

> +	int ret;

> +	unsigned int val;

> +

> +	/* Once read successfully */

> +	if (info->cell_count)

> +		return info->cell_count;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);

> +	if (ret)

> +		return 0;

> +

> +	/* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */

> +	val &= 0x0f;

> +	if (!val)

> +		return 0;

> +

> +	/* Once determined, keep the value */

> +	info->cell_count = val;

> +

> +	return val;

> +};

> +

> +/* Convert enum value to POWER_SUPPLY_STATUS value */

> +static int ltc4162l_state_decode(enum ltc4162l_state value)

> +{

> +	switch (value) {

> +	case precharge:

> +	case cc_cv_charge:

> +		return POWER_SUPPLY_STATUS_CHARGING;

> +	case c_over_x_term:

> +		return POWER_SUPPLY_STATUS_FULL;

> +	case bat_missing_fault:

> +	case bat_short_fault:

> +		return POWER_SUPPLY_STATUS_UNKNOWN;

> +	default:

> +		return POWER_SUPPLY_STATUS_NOT_CHARGING;

> +	}

> +};

> +

> +static int ltc4162l_get_status(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

> +	if (ret) {

> +		dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");

> +		return ret;

> +	}

> +

> +	val->intval = ltc4162l_state_decode(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)

> +{

> +	if (!value)

> +		return POWER_SUPPLY_CHARGE_TYPE_NONE;

> +

> +	/* constant voltage/current and input_current limit are "fast" modes */

> +	if (value <= iin_limit_active)

> +		return POWER_SUPPLY_CHARGE_TYPE_FAST;

> +

> +	/* Anything that's not fast we'll return as trickle */

> +	return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

> +}

> +

> +static int ltc4162l_get_charge_type(struct ltc4162l_info *info,

> +				    union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	val->intval = ltc4162l_charge_status_decode(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_state_to_health(enum ltc4162l_state value)

> +{

> +	switch (value) {

> +	case ntc_pause:

> +		return POWER_SUPPLY_HEALTH_OVERHEAT;

> +	case timer_term:

> +		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;

> +	case max_charge_time_fault:

> +		return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;

> +	case bat_missing_fault:

> +		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;

> +	case bat_short_fault:

> +		return POWER_SUPPLY_HEALTH_DEAD;

> +	default:

> +		return POWER_SUPPLY_HEALTH_GOOD;

> +	}

> +}

> +

> +static int ltc4162l_get_health(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	val->intval = ltc4162l_state_to_health(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_online(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* BIT(2) indicates if input voltage is sufficient to charge */

> +	val->intval = !!(regval & BIT(2));

> +

> +	return 0;

> +}

> +

> +

> +static int ltc4162l_get_vbat(struct ltc4162l_info *info,

> +				  unsigned int reg,

> +				  union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* cell_count × 192.4μV/LSB */

> +	regval *= 1924;

> +	regval *= ltc4162l_get_cell_count(info);

> +	regval /= 10;

> +	val->intval = regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_ibat(struct ltc4162l_info *info,

> +			     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */

> +	ret = (s16)(regval & 0xFFFF);

> +	val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_icharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

> +

> +	/* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */

> +	++regval;

> +	val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_icharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				unsigned int value)

> +{

> +	value = mult_frac(value, info->rsnsb, 100000u);

> +	value /= 10000u;

> +

> +	/* Round to lowest possible */

> +	if (value)

> +		--value;

> +

> +	if (value > 31)

> +		return -EINVAL;

> +

> +	return regmap_write(info->regmap, reg, value);

> +}

> +

> +

> +static int ltc4162l_get_vcharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +	u32 voltage;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

> +

> +	/*

> +	 * charge voltage setting can be computed from

> +	 * cell_count × (vcharge_setting × 12.5mV + 3.8125V)

> +	 * where vcharge_setting ranges from 0 to 31 (4.2V max).

> +	 */

> +	voltage = 3812500 + (regval * 12500);

> +	voltage *= ltc4162l_get_cell_count(info);

> +	val->intval = voltage;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_vcharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				unsigned int value)

> +{

> +	u8 cell_count = ltc4162l_get_cell_count(info);

> +

> +	if (!cell_count)

> +		return -EBUSY; /* Not available yet, try again later */

> +

> +	value /= cell_count;

> +

> +	if (value < 3812500)

> +		return -EINVAL;

> +

> +	value -= 3812500;

> +	value /= 12500;

> +

> +	if (value > 31)

> +		return -EINVAL;

> +

> +	return regmap_write(info->regmap, reg, value);

> +}

> +

> +static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,

> +				     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only 6 bits */

> +

> +	/* (iin_limit_dac + 1) × 500μV / RSNSI */

> +	++regval;

> +	regval *= 5000000u;

> +	regval /= info->rsnsi;

> +	val->intval = 100u * regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,

> +				  unsigned int value)

> +{

> +	unsigned int regval;

> +

> +	regval = mult_frac(value, info->rsnsi, 50000u);

> +	regval /= 10000u;

> +	if (regval)

> +		--regval;

> +	if (regval > 63)

> +		regval = 63;

> +

> +	return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);

> +}

> +

> +static int ltc4162l_get_die_temp(struct ltc4162l_info *info,

> +				 union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* die_temp × 0.0215°C/LSB - 264.4°C */

> +	ret = (s16)(regval & 0xFFFF);

> +	ret *= 215;

> +	ret /= 100; /* Centidegrees scale */

> +	ret -= 26440;

> +	val->intval = ret;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_term_current(struct ltc4162l_info *info,

> +				     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Check if C_OVER_X_THRESHOLD is enabled */

> +	if (!(regval & BIT(2))) {

> +		val->intval = 0;

> +		return 0;

> +	}

> +

> +	ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* 1.466μV / RSNSB amperes/LSB */

> +	regval *= 14660u;

> +	regval /= info->rsnsb;

> +	val->intval = 100 * regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_term_current(struct ltc4162l_info *info,

> +				     unsigned int value)

> +{

> +	int ret;

> +	unsigned int regval;

> +

> +	if (!value) {

> +		/* Disable en_c_over_x_term when set to zero */

> +		return regmap_update_bits(info->regmap,

> +					  LTC4162L_CHARGER_CONFIG_BITS,

> +					  BIT(2), 0);

> +	}

> +

> +	regval = mult_frac(value, info->rsnsb, 14660u);

> +	regval /= 100u;

> +

> +	ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Set en_c_over_x_term after changing the threshold value */

> +	return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,

> +				  BIT(2), BIT(2));

> +}

> +

> +/* Custom properties */

> +static const char * const ltc4162l_charge_status_name[] = {

> +	"ilim_reg_active", /* 32 */

> +	"thermal_reg_active",

> +	"vin_uvcl_active",

> +	"iin_limit_active",

> +	"constant_current",

> +	"constant_voltage",

> +	"charger_off" /* 0 */

> +};

> +

> +static ssize_t charge_status_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	const char *result = ltc4162l_charge_status_name[

> +				ARRAY_SIZE(ltc4162l_charge_status_name) - 1];

> +	unsigned int regval;

> +	unsigned int mask;

> +	unsigned int index;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Only one bit is set according to datasheet, let's be safe here */

> +	for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {

> +		if (regval & mask) {

> +			result = ltc4162l_charge_status_name[index];

> +			break;

> +		}

> +	}

> +

> +	return sprintf(buf, "%s\n", result);

> +}

> +static DEVICE_ATTR_RO(charge_status);

> +

> +static ssize_t input_voltage_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* 1.649mV/LSB */

> +	regval *= 1694;

> +

> +	return sprintf(buf, "%u\n", regval);

> +}

> +static DEVICE_ATTR_RO(input_voltage);

> +

> +static ssize_t input_current_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */

> +	ret = (s16)(regval & 0xFFFF);

> +	ret *= 14660;

> +	ret /= info->rsnsi;

> +	ret *= 100;

> +

> +	return sprintf(buf, "%d\n", ret);

> +}

> +static DEVICE_ATTR_RO(input_current);

> +

> +static ssize_t force_telemetry_show(struct device *dev,

> +				    struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);

> +	if (ret)

> +		return ret;

> +

> +	return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);

> +}

> +

> +static ssize_t force_telemetry_store(struct device *dev,

> +	struct device_attribute *attr,

> +	const char *buf,

> +	size_t count)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	int ret;

> +	unsigned int value;

> +

> +	ret = kstrtouint(buf, 0, &value);

> +	if (ret < 0)

> +		return ret;

> +

> +	ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,

> +				 BIT(2), value ? BIT(2) : 0);

> +	if (ret < 0)

> +		return ret;

> +

> +	return count;

> +}

> +

> +static DEVICE_ATTR_RW(force_telemetry);

> +

> +static ssize_t arm_ship_mode_show(struct device *dev,

> +				    struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	return sprintf(buf, "%u\n",

> +		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);

> +}

> +

> +static ssize_t arm_ship_mode_store(struct device *dev,

> +	struct device_attribute *attr,

> +	const char *buf,

> +	size_t count)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	int ret;

> +	unsigned int value;

> +

> +	ret = kstrtouint(buf, 0, &value);

> +	if (ret < 0)

> +		return ret;

> +

> +	ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,

> +				value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);

> +	if (ret < 0)

> +		return ret;

> +

> +	return count;

> +}

> +

> +static DEVICE_ATTR_RW(arm_ship_mode);

> +

> +static struct attribute *ltc4162l_sysfs_entries[] = {

> +	&dev_attr_charge_status.attr,

> +	&dev_attr_input_voltage.attr,

> +	&dev_attr_input_current.attr,

> +	&dev_attr_force_telemetry.attr,

> +	&dev_attr_arm_ship_mode.attr,

> +	NULL,

> +};

> +

> +static struct attribute_group ltc4162l_attr_group = {

> +	.name	= NULL,	/* put in device directory */

> +	.attrs	= ltc4162l_sysfs_entries,

> +};

> +

> +static int ltc4162l_get_property(struct power_supply *psy,

> +				 enum power_supply_property psp,

> +				 union power_supply_propval *val)

> +{

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_STATUS:

> +		return ltc4162l_get_status(info, val);

> +	case POWER_SUPPLY_PROP_CHARGE_TYPE:

> +		return ltc4162l_get_charge_type(info, val);

> +	case POWER_SUPPLY_PROP_HEALTH:

> +		return ltc4162l_get_health(info, val);

> +	case POWER_SUPPLY_PROP_ONLINE:

> +		return ltc4162l_get_online(info, val);

> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:

> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT, val);

> +	case POWER_SUPPLY_PROP_VOLTAGE_AVG:

> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, val);

> +	case POWER_SUPPLY_PROP_CURRENT_NOW:

> +		return ltc4162l_get_ibat(info, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:

> +		return ltc4162l_get_icharge(info,

> +				LTC4162L_ICHARGE_DAC, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +		return ltc4162l_get_icharge(info,

> +				LTC4162L_CHARGE_CURRENT_SETTING, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:

> +		return ltc4162l_get_vcharge(info,

> +				LTC4162L_VCHARGE_DAC, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +		return ltc4162l_get_vcharge(info,

> +				LTC4162L_VCHARGE_SETTING, val);

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +		return ltc4162l_get_iin_limit_dac(info, val);

> +	case POWER_SUPPLY_PROP_TEMP:

> +		return ltc4162l_get_die_temp(info, val);

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return ltc4162l_get_term_current(info, val);

> +	default:

> +		return -EINVAL;

> +	}

> +}

> +

> +static int ltc4162l_set_property(struct power_supply *psy,

> +					 enum power_supply_property psp,

> +					 const union power_supply_propval *val)

> +{

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +		return ltc4162l_set_icharge(info,

> +				LTC4162L_CHARGE_CURRENT_SETTING, val->intval);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +		return ltc4162l_set_vcharge(info,

> +				LTC4162L_VCHARGE_SETTING, val->intval);

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +		return ltc4162l_set_iin_limit(info, val->intval);

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return ltc4162l_set_term_current(info, val->intval);

> +	default:

> +		return -EINVAL;

> +	}

> +}

> +

> +static int ltc4162l_property_is_writeable(struct power_supply *psy,

> +						enum power_supply_property psp)

> +{

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return 1;

> +	default:

> +		return 0;

> +	}

> +}

> +

> +/* Charger power supply property routines */

> +static enum power_supply_property ltc4162l_properties[] = {

> +	POWER_SUPPLY_PROP_STATUS,

> +	POWER_SUPPLY_PROP_CHARGE_TYPE,

> +	POWER_SUPPLY_PROP_HEALTH,

> +	POWER_SUPPLY_PROP_ONLINE,

> +	POWER_SUPPLY_PROP_VOLTAGE_NOW, /* Reports battery voltage */

> +	POWER_SUPPLY_PROP_VOLTAGE_AVG,

> +	POWER_SUPPLY_PROP_CURRENT_NOW, /* Reports battery current */

> +	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_INPUT_CURRENT_LIMIT,

> +	POWER_SUPPLY_PROP_TEMP,

> +	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,

> +};

> +

> +static const struct power_supply_desc ltc4162l_desc = {

> +	.name		= "ltc4162-l",

> +	.type		= POWER_SUPPLY_TYPE_MAINS,

> +	.properties	= ltc4162l_properties,

> +	.num_properties	= ARRAY_SIZE(ltc4162l_properties),

> +	.get_property	= ltc4162l_get_property,

> +	.set_property	= ltc4162l_set_property,

> +	.property_is_writeable = ltc4162l_property_is_writeable,

> +};

> +

> +static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)

> +{

> +	/* all registers up to this one are writeable */

> +	if (reg <= LTC4162L_CHARGER_CONFIG_BITS)

> +		return true;

> +

> +	/* The ALERTS registers can be written to clear alerts */

> +	if (reg >= LTC4162L_LIMIT_ALERTS_REG &&

> +	    reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)

> +		return true;

> +

> +	return false;

> +}

> +

> +static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)

> +{

> +	/* all registers after this one are read-only status registers */

> +	return reg > LTC4162L_CHARGER_CONFIG_BITS;

> +}

> +

> +static const struct regmap_config ltc4162l_regmap_config = {

> +	.reg_bits	= 8,

> +	.val_bits	= 16,

> +	.val_format_endian = REGMAP_ENDIAN_LITTLE,

> +	.writeable_reg	= ltc4162l_is_writeable_reg,

> +	.volatile_reg	= ltc4162l_is_volatile_reg,

> +	.max_register	= LTC4162L_INPUT_UNDERVOLTAGE_DAC,

> +	.cache_type	= REGCACHE_RBTREE,

> +};

> +

> +static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)

> +{

> +	/* Acknowledge interrupt to chip by clearing all events */

> +	regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);

> +	regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);

> +	regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);

> +}

> +

> +static int ltc4162l_probe(struct i2c_client *client,

> +			const struct i2c_device_id *id)

> +{

> +	struct i2c_adapter *adapter = client->adapter;

> +	struct device *dev = &client->dev;

> +	struct ltc4162l_info *info;

> +	struct power_supply_config ltc4162l_config = {};

> +	u32 value;

> +	int ret;

> +

> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {

> +		dev_err(dev, "No support for SMBUS_WORD_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, &ltc4162l_regmap_config);

> +	if (IS_ERR(info->regmap)) {

> +		dev_err(dev, "Failed to initialize register map\n");

> +		return PTR_ERR(info->regmap);

> +	}

> +

> +	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",

> +				       &info->rsnsb);

> +	if (ret) {

> +		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");

> +		return ret;

> +	}

> +	if (!info->rsnsb)

> +		return -EINVAL;

> +

> +	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",

> +				       &info->rsnsi);

> +	if (ret) {

> +		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");

> +		return ret;

> +	}

> +	if (!info->rsnsi)

> +		return -EINVAL;

> +

> +	if (!device_property_read_u32(dev, "lltc,cell-count", &value))

> +		info->cell_count = value;

> +

> +	ltc4162l_config.of_node = dev->of_node;

> +	ltc4162l_config.drv_data = info;

> +

> +	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,

> +						   &ltc4162l_config);

> +	if (IS_ERR(info->charger)) {

> +		dev_err(dev, "Failed to register charger\n");

> +		return PTR_ERR(info->charger);

> +	}

> +

> +	ret = sysfs_create_group(&info->charger->dev.kobj,

> +				 &ltc4162l_attr_group);

> +	if (ret)

> +		dev_err(dev, "failed to create extra sysfs entries\n");

> +

> +	/* Disable the threshold alerts, we're not using them */

> +	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);

> +

> +	/* Enable interrupts on all status changes */

> +	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,

> +		     0x1fff);

> +	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);

> +

> +	ltc4162l_clear_interrupts(info);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_remove(struct i2c_client *client)

> +{

> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

> +

> +	sysfs_remove_group(&info->charger->dev.kobj, &ltc4162l_attr_group);

> +

> +	return 0;

> +}

> +

> +static void ltc4162l_alert(struct i2c_client *client,

> +			   enum i2c_alert_protocol type, unsigned int flag)

> +{

> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

> +

> +	if (type != I2C_PROTOCOL_SMBUS_ALERT)

> +		return;

> +

> +	ltc4162l_clear_interrupts(info);

> +	power_supply_changed(info->charger);

> +}

> +

> +static const struct i2c_device_id ltc4162l_i2c_id_table[] = {

> +	{ "ltc4162-l", 0 },

> +	{ },

> +};

> +MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);

> +

> +static const struct of_device_id ltc4162l_of_match[] = {

> +	{ .compatible = "lltc,ltc4162-l", },

> +	{ },

> +};

> +MODULE_DEVICE_TABLE(of, ltc4162l_of_match);

> +

> +static struct i2c_driver ltc4162l_driver = {

> +	.probe		= ltc4162l_probe,

> +	.remove		= ltc4162l_remove,

> +	.alert		= ltc4162l_alert,

> +	.id_table	= ltc4162l_i2c_id_table,

> +	.driver = {

> +		.name		= "ltc4162-l-charger",

> +		.of_match_table	= of_match_ptr(ltc4162l_of_match),

> +	},

> +};

> +module_i2c_driver(ltc4162l_driver);

> +

> +MODULE_LICENSE("GPL");

> +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");

> +MODULE_DESCRIPTION("LTC4162-L charger driver");



-- 
Mike Looijmans
Sebastian Reichel Dec. 29, 2020, 2:57 p.m. UTC | #2
Hi,

Sorry for slow processing of this. Driver looks mostly fine, but I
do have some comments.

On Mon, Nov 02, 2020 at 10:21:31AM +0100, Mike Looijmans wrote:
> Add support for the LTC4162-L Li-Ion battery charger. The driver allows

> reading back telemetry and to set some charging options like the input

> current limit.

> 

> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>

> ---

> v2: Use microohm units instead of milliohm

>     Add interrupt support using smbalert

>     Support obtaining cell-count from devicetree

> v3: Fix overflows in calculations involving resistor values

> resent, mail bounced

> 

>  drivers/power/supply/Kconfig             |   8 +

>  drivers/power/supply/Makefile            |   1 +

>  drivers/power/supply/ltc4162-l-charger.c | 898 +++++++++++++++++++++++

>  3 files changed, 907 insertions(+)

>  create mode 100644 drivers/power/supply/ltc4162-l-charger.c

> 

> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig

> index eec646c568b7..23000976cb42 100644

> --- a/drivers/power/supply/Kconfig

> +++ b/drivers/power/supply/Kconfig

> @@ -513,6 +513,14 @@ config CHARGER_LT3651

>  	  Say Y to include support for the Analog Devices (Linear Technology)

>  	  LT3651 battery charger which reports its status via GPIO lines.

>  

> +config CHARGER_LTC4162L

> +	tristate "LTC4162-L charger"

> +	depends on I2C

> +	select REGMAP_I2C

> +	help

> +	  Say Y to include support for the Analog Devices (Linear Technology)

> +	  LTC4162-L battery charger connected to I2C.

> +

>  config CHARGER_MAX14577

>  	tristate "Maxim MAX14577/77836 battery charger driver"

>  	depends on MFD_MAX14577

> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile

> index dd4b86318cd9..17b1cf921c44 100644

> --- a/drivers/power/supply/Makefile

> +++ b/drivers/power/supply/Makefile

> @@ -70,6 +70,7 @@ obj-$(CONFIG_CHARGER_LP8788)	+= lp8788-charger.o

>  obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o

>  obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o

>  obj-$(CONFIG_CHARGER_LT3651)	+= lt3651-charger.o

> +obj-$(CONFIG_CHARGER_LTC4162L)	+= ltc4162-l-charger.o

>  obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o

>  obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o

>  obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o

> diff --git a/drivers/power/supply/ltc4162-l-charger.c b/drivers/power/supply/ltc4162-l-charger.c

> new file mode 100644

> index 000000000000..b2f666113125

> --- /dev/null

> +++ b/drivers/power/supply/ltc4162-l-charger.c

> @@ -0,0 +1,898 @@

> +// SPDX-License-Identifier: GPL-2.0-or-later

> +/*

> + *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.

> + *  Copyright (C) 2020, Topic Embedded Products

> + */

> +

> +#include <linux/module.h>

> +#include <linux/delay.h>

> +#include <linux/of_device.h>

> +#include <linux/pm_runtime.h>

> +#include <linux/power_supply.h>

> +#include <linux/i2c.h>

> +#include <linux/regmap.h>

> +

> +/* Registers (names based on what datasheet uses) */

> +#define LTC4162L_EN_LIMIT_ALERTS_REG		0x0D

> +#define LTC4162L_EN_CHARGER_STATE_ALERTS_REG	0x0E

> +#define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG	0x0F

> +#define LTC4162L_CONFIG_BITS_REG		0x14

> +#define LTC4162L_IIN_LIMIT_TARGET		0x15

> +#define LTC4162L_ARM_SHIP_MODE			0x19

> +#define LTC4162L_CHARGE_CURRENT_SETTING		0X1A

> +#define LTC4162L_VCHARGE_SETTING		0X1B

> +#define LTC4162L_C_OVER_X_THRESHOLD		0x1C

> +#define LTC4162L_MAX_CV_TIME			0X1D

> +#define LTC4162L_MAX_CHARGE_TIME		0X1E

> +#define LTC4162L_CHARGER_CONFIG_BITS		0x29

> +#define LTC4162L_CHARGER_STATE			0x34

> +#define LTC4162L_CHARGE_STATUS			0x35

> +#define LTC4162L_LIMIT_ALERTS_REG		0x36

> +#define LTC4162L_CHARGER_STATE_ALERTS_REG	0x37

> +#define LTC4162L_CHARGE_STATUS_ALERTS_REG	0x38

> +#define LTC4162L_SYSTEM_STATUS_REG		0x39

> +#define LTC4162L_VBAT				0x3A

> +#define LTC4162L_VIN				0x3B

> +#define LTC4162L_VOUT				0x3C

> +#define LTC4162L_IBAT				0x3D

> +#define LTC4162L_IIN				0x3E

> +#define LTC4162L_DIE_TEMPERATURE		0x3F

> +#define LTC4162L_THERMISTOR_VOLTAGE		0x40

> +#define LTC4162L_BSR				0x41

> +#define LTC4162L_JEITA_REGION			0x42

> +#define LTC4162L_CHEM_CELLS_REG			0x43

> +#define LTC4162L_ICHARGE_DAC			0x44

> +#define LTC4162L_VCHARGE_DAC			0x45

> +#define LTC4162L_IIN_LIMIT_DAC			0x46

> +#define LTC4162L_VBAT_FILT			0x47

> +#define LTC4162L_INPUT_UNDERVOLTAGE_DAC		0x4B

> +

> +/* Enumeration as in datasheet. Individual bits are mutually exclusive. */

> +enum ltc4162l_state {

> +	battery_detection = 2048,

> +	charger_suspended = 256,

> +	precharge = 128,   /* trickle on low bat voltage */

> +	cc_cv_charge = 64, /* normal charge */

> +	ntc_pause = 32,

> +	timer_term = 16,

> +	c_over_x_term = 8, /* battery is full */

> +	max_charge_time_fault = 4,

> +	bat_missing_fault = 2,

> +	bat_short_fault = 1

> +};

> +

> +/* Individual bits are mutually exclusive. Only active in charging states.*/

> +enum ltc4162l_charge_status {

> +	ilim_reg_active = 32,

> +	thermal_reg_active = 16,

> +	vin_uvcl_active = 8,

> +	iin_limit_active = 4,

> +	constant_current = 2,

> +	constant_voltage = 1,

> +	charger_off = 0

> +};


+use BIT(0), BIT(1), ...

> +/* Magic number to write to ARM_SHIP_MODE register */

> +#define LTC4162L_ARM_SHIP_MODE_MAGIC 21325

> +

> +struct ltc4162l_info {

> +	struct i2c_client	*client;

> +	struct regmap		*regmap;

> +	struct power_supply	*charger;

> +	u32 rsnsb;	/* Series resistor that sets charge current, microOhm */

> +	u32 rsnsi;	/* Series resistor to measure input current, microOhm */

> +	u8 cell_count;	/* Number of connected cells, 0 while unknown */

> +};

> +

> +static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)

> +{

> +	int ret;

> +	unsigned int val;

> +

> +	/* Once read successfully */

> +	if (info->cell_count)

> +		return info->cell_count;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);

> +	if (ret)

> +		return 0;

> +

> +	/* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */

> +	val &= 0x0f;

> +	if (!val)

> +		return 0;

> +

> +	/* Once determined, keep the value */

> +	info->cell_count = val;

> +

> +	return val;

> +};

> +

> +/* Convert enum value to POWER_SUPPLY_STATUS value */

> +static int ltc4162l_state_decode(enum ltc4162l_state value)

> +{

> +	switch (value) {

> +	case precharge:

> +	case cc_cv_charge:

> +		return POWER_SUPPLY_STATUS_CHARGING;

> +	case c_over_x_term:

> +		return POWER_SUPPLY_STATUS_FULL;

> +	case bat_missing_fault:

> +	case bat_short_fault:

> +		return POWER_SUPPLY_STATUS_UNKNOWN;

> +	default:

> +		return POWER_SUPPLY_STATUS_NOT_CHARGING;

> +	}

> +};

> +

> +static int ltc4162l_get_status(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

> +	if (ret) {

> +		dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");

> +		return ret;

> +	}

> +

> +	val->intval = ltc4162l_state_decode(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)

> +{

> +	if (!value)

> +		return POWER_SUPPLY_CHARGE_TYPE_NONE;

> +

> +	/* constant voltage/current and input_current limit are "fast" modes */

> +	if (value <= iin_limit_active)

> +		return POWER_SUPPLY_CHARGE_TYPE_FAST;

> +

> +	/* Anything that's not fast we'll return as trickle */

> +	return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

> +}

> +

> +static int ltc4162l_get_charge_type(struct ltc4162l_info *info,

> +				    union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	val->intval = ltc4162l_charge_status_decode(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_state_to_health(enum ltc4162l_state value)

> +{

> +	switch (value) {

> +	case ntc_pause:

> +		return POWER_SUPPLY_HEALTH_OVERHEAT;

> +	case timer_term:

> +		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;

> +	case max_charge_time_fault:

> +		return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;

> +	case bat_missing_fault:

> +		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;

> +	case bat_short_fault:

> +		return POWER_SUPPLY_HEALTH_DEAD;

> +	default:

> +		return POWER_SUPPLY_HEALTH_GOOD;

> +	}

> +}

> +

> +static int ltc4162l_get_health(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	val->intval = ltc4162l_state_to_health(regval);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_online(struct ltc4162l_info *info,

> +			       union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* BIT(2) indicates if input voltage is sufficient to charge */

> +	val->intval = !!(regval & BIT(2));

> +

> +	return 0;

> +}

> +

> +

> +static int ltc4162l_get_vbat(struct ltc4162l_info *info,

> +				  unsigned int reg,

> +				  union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* cell_count × 192.4μV/LSB */

> +	regval *= 1924;

> +	regval *= ltc4162l_get_cell_count(info);

> +	regval /= 10;

> +	val->intval = regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_ibat(struct ltc4162l_info *info,

> +			     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */

> +	ret = (s16)(regval & 0xFFFF);

> +	val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_icharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

> +

> +	/* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */

> +	++regval;

> +	val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_icharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				unsigned int value)

> +{

> +	value = mult_frac(value, info->rsnsb, 100000u);

> +	value /= 10000u;

> +

> +	/* Round to lowest possible */

> +	if (value)

> +		--value;

> +

> +	if (value > 31)

> +		return -EINVAL;

> +

> +	return regmap_write(info->regmap, reg, value);

> +}

> +

> +

> +static int ltc4162l_get_vcharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +	u32 voltage;

> +

> +	ret = regmap_read(info->regmap, reg, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

> +

> +	/*

> +	 * charge voltage setting can be computed from

> +	 * cell_count × (vcharge_setting × 12.5mV + 3.8125V)

> +	 * where vcharge_setting ranges from 0 to 31 (4.2V max).

> +	 */

> +	voltage = 3812500 + (regval * 12500);

> +	voltage *= ltc4162l_get_cell_count(info);

> +	val->intval = voltage;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_vcharge(struct ltc4162l_info *info,

> +				unsigned int reg,

> +				unsigned int value)

> +{

> +	u8 cell_count = ltc4162l_get_cell_count(info);

> +

> +	if (!cell_count)

> +		return -EBUSY; /* Not available yet, try again later */

> +

> +	value /= cell_count;

> +

> +	if (value < 3812500)

> +		return -EINVAL;

> +

> +	value -= 3812500;

> +	value /= 12500;

> +

> +	if (value > 31)

> +		return -EINVAL;

> +

> +	return regmap_write(info->regmap, reg, value);

> +}

> +

> +static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,

> +				     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);

> +	if (ret)

> +		return ret;

> +

> +	regval &= BIT(6) - 1; /* Only 6 bits */

> +

> +	/* (iin_limit_dac + 1) × 500μV / RSNSI */

> +	++regval;

> +	regval *= 5000000u;

> +	regval /= info->rsnsi;

> +	val->intval = 100u * regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,

> +				  unsigned int value)

> +{

> +	unsigned int regval;

> +

> +	regval = mult_frac(value, info->rsnsi, 50000u);

> +	regval /= 10000u;

> +	if (regval)

> +		--regval;

> +	if (regval > 63)

> +		regval = 63;

> +

> +	return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);

> +}

> +

> +static int ltc4162l_get_die_temp(struct ltc4162l_info *info,

> +				 union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* die_temp × 0.0215°C/LSB - 264.4°C */

> +	ret = (s16)(regval & 0xFFFF);

> +	ret *= 215;

> +	ret /= 100; /* Centidegrees scale */

> +	ret -= 26440;

> +	val->intval = ret;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_get_term_current(struct ltc4162l_info *info,

> +				     union power_supply_propval *val)

> +{

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Check if C_OVER_X_THRESHOLD is enabled */

> +	if (!(regval & BIT(2))) {

> +		val->intval = 0;

> +		return 0;

> +	}

> +

> +	ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* 1.466μV / RSNSB amperes/LSB */

> +	regval *= 14660u;

> +	regval /= info->rsnsb;

> +	val->intval = 100 * regval;

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_set_term_current(struct ltc4162l_info *info,

> +				     unsigned int value)

> +{

> +	int ret;

> +	unsigned int regval;

> +

> +	if (!value) {

> +		/* Disable en_c_over_x_term when set to zero */

> +		return regmap_update_bits(info->regmap,

> +					  LTC4162L_CHARGER_CONFIG_BITS,

> +					  BIT(2), 0);

> +	}

> +

> +	regval = mult_frac(value, info->rsnsb, 14660u);

> +	regval /= 100u;

> +

> +	ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Set en_c_over_x_term after changing the threshold value */

> +	return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,

> +				  BIT(2), BIT(2));

> +}

> +

> +/* Custom properties */

> +static const char * const ltc4162l_charge_status_name[] = {

> +	"ilim_reg_active", /* 32 */

> +	"thermal_reg_active",

> +	"vin_uvcl_active",

> +	"iin_limit_active",

> +	"constant_current",

> +	"constant_voltage",

> +	"charger_off" /* 0 */

> +};

> +

> +static ssize_t charge_status_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	const char *result = ltc4162l_charge_status_name[

> +				ARRAY_SIZE(ltc4162l_charge_status_name) - 1];

> +	unsigned int regval;

> +	unsigned int mask;

> +	unsigned int index;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Only one bit is set according to datasheet, let's be safe here */

> +	for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {

> +		if (regval & mask) {

> +			result = ltc4162l_charge_status_name[index];

> +			break;

> +		}

> +	}

> +

> +	return sprintf(buf, "%s\n", result);

> +}

> +static DEVICE_ATTR_RO(charge_status);

> +

> +static ssize_t input_voltage_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* 1.649mV/LSB */

> +	regval *= 1694;

> +

> +	return sprintf(buf, "%u\n", regval);

> +}

> +static DEVICE_ATTR_RO(input_voltage);

> +

> +static ssize_t input_current_show(struct device *dev,

> +				  struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);

> +	if (ret)

> +		return ret;

> +

> +	/* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */

> +	ret = (s16)(regval & 0xFFFF);

> +	ret *= 14660;

> +	ret /= info->rsnsi;

> +	ret *= 100;

> +

> +	return sprintf(buf, "%d\n", ret);

> +}

> +static DEVICE_ATTR_RO(input_current);

> +

> +static ssize_t force_telemetry_show(struct device *dev,

> +				    struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);

> +	if (ret)

> +		return ret;

> +

> +	return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);

> +}

> +

> +static ssize_t force_telemetry_store(struct device *dev,

> +	struct device_attribute *attr,

> +	const char *buf,

> +	size_t count)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	int ret;

> +	unsigned int value;

> +

> +	ret = kstrtouint(buf, 0, &value);

> +	if (ret < 0)

> +		return ret;

> +

> +	ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,

> +				 BIT(2), value ? BIT(2) : 0);

> +	if (ret < 0)

> +		return ret;

> +

> +	return count;

> +}

> +

> +static DEVICE_ATTR_RW(force_telemetry);

> +

> +static ssize_t arm_ship_mode_show(struct device *dev,

> +				    struct device_attribute *attr, char *buf)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	unsigned int regval;

> +	int ret;

> +

> +	ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);

> +	if (ret)

> +		return ret;

> +

> +	return sprintf(buf, "%u\n",

> +		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);

> +}

> +

> +static ssize_t arm_ship_mode_store(struct device *dev,

> +	struct device_attribute *attr,

> +	const char *buf,

> +	size_t count)

> +{

> +	struct power_supply *psy = to_power_supply(dev);

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +	int ret;

> +	unsigned int value;

> +

> +	ret = kstrtouint(buf, 0, &value);

> +	if (ret < 0)

> +		return ret;

> +

> +	ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,

> +				value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);

> +	if (ret < 0)

> +		return ret;

> +

> +	return count;

> +}

> +

> +static DEVICE_ATTR_RW(arm_ship_mode);

> +

> +static struct attribute *ltc4162l_sysfs_entries[] = {

> +	&dev_attr_charge_status.attr,

> +	&dev_attr_input_voltage.attr,

> +	&dev_attr_input_current.attr,

> +	&dev_attr_force_telemetry.attr,

> +	&dev_attr_arm_ship_mode.attr,

> +	NULL,

> +};

> +

> +static struct attribute_group ltc4162l_attr_group = {

> +	.name	= NULL,	/* put in device directory */

> +	.attrs	= ltc4162l_sysfs_entries,

> +};

> +

> +static int ltc4162l_get_property(struct power_supply *psy,

> +				 enum power_supply_property psp,

> +				 union power_supply_propval *val)

> +{

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_STATUS:

> +		return ltc4162l_get_status(info, val);

> +	case POWER_SUPPLY_PROP_CHARGE_TYPE:

> +		return ltc4162l_get_charge_type(info, val);

> +	case POWER_SUPPLY_PROP_HEALTH:

> +		return ltc4162l_get_health(info, val);

> +	case POWER_SUPPLY_PROP_ONLINE:

> +		return ltc4162l_get_online(info, val);

> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:

> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT, val);

> +	case POWER_SUPPLY_PROP_VOLTAGE_AVG:

> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, val);

> +	case POWER_SUPPLY_PROP_CURRENT_NOW:

> +		return ltc4162l_get_ibat(info, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:

> +		return ltc4162l_get_icharge(info,

> +				LTC4162L_ICHARGE_DAC, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +		return ltc4162l_get_icharge(info,

> +				LTC4162L_CHARGE_CURRENT_SETTING, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:

> +		return ltc4162l_get_vcharge(info,

> +				LTC4162L_VCHARGE_DAC, val);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +		return ltc4162l_get_vcharge(info,

> +				LTC4162L_VCHARGE_SETTING, val);

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +		return ltc4162l_get_iin_limit_dac(info, val);

> +	case POWER_SUPPLY_PROP_TEMP:

> +		return ltc4162l_get_die_temp(info, val);

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return ltc4162l_get_term_current(info, val);

> +	default:

> +		return -EINVAL;

> +	}

> +}

> +

> +static int ltc4162l_set_property(struct power_supply *psy,

> +					 enum power_supply_property psp,

> +					 const union power_supply_propval *val)

> +{

> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

> +

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +		return ltc4162l_set_icharge(info,

> +				LTC4162L_CHARGE_CURRENT_SETTING, val->intval);

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +		return ltc4162l_set_vcharge(info,

> +				LTC4162L_VCHARGE_SETTING, val->intval);

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +		return ltc4162l_set_iin_limit(info, val->intval);

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return ltc4162l_set_term_current(info, val->intval);

> +	default:

> +		return -EINVAL;

> +	}

> +}

> +

> +static int ltc4162l_property_is_writeable(struct power_supply *psy,

> +						enum power_supply_property psp)

> +{

> +	switch (psp) {

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

> +		return 1;

> +	default:

> +		return 0;

> +	}

> +}

> +

> +/* Charger power supply property routines */

> +static enum power_supply_property ltc4162l_properties[] = {

> +	POWER_SUPPLY_PROP_STATUS,

> +	POWER_SUPPLY_PROP_CHARGE_TYPE,

> +	POWER_SUPPLY_PROP_HEALTH,

> +	POWER_SUPPLY_PROP_ONLINE,

> +	POWER_SUPPLY_PROP_VOLTAGE_NOW, /* Reports battery voltage */

> +	POWER_SUPPLY_PROP_VOLTAGE_AVG,

> +	POWER_SUPPLY_PROP_CURRENT_NOW, /* Reports battery current */


above 3 properties should describe input voltage/current for chargers,
see Documentation/ABI/testing/sysfs-class-power

Battery IBAT and VBAT can currently only be reported from
POWER_SUPPLY_TYPE_BATTERY.

> +	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_INPUT_CURRENT_LIMIT,

> +	POWER_SUPPLY_PROP_TEMP,

> +	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,

> +};

> +

> +static const struct power_supply_desc ltc4162l_desc = {

> +	.name		= "ltc4162-l",

> +	.type		= POWER_SUPPLY_TYPE_MAINS,

> +	.properties	= ltc4162l_properties,

> +	.num_properties	= ARRAY_SIZE(ltc4162l_properties),

> +	.get_property	= ltc4162l_get_property,

> +	.set_property	= ltc4162l_set_property,

> +	.property_is_writeable = ltc4162l_property_is_writeable,

> +};

> +

> +static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)

> +{

> +	/* all registers up to this one are writeable */

> +	if (reg <= LTC4162L_CHARGER_CONFIG_BITS)

> +		return true;

> +

> +	/* The ALERTS registers can be written to clear alerts */

> +	if (reg >= LTC4162L_LIMIT_ALERTS_REG &&

> +	    reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)

> +		return true;

> +

> +	return false;

> +}

> +

> +static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)

> +{

> +	/* all registers after this one are read-only status registers */

> +	return reg > LTC4162L_CHARGER_CONFIG_BITS;

> +}

> +

> +static const struct regmap_config ltc4162l_regmap_config = {

> +	.reg_bits	= 8,

> +	.val_bits	= 16,

> +	.val_format_endian = REGMAP_ENDIAN_LITTLE,

> +	.writeable_reg	= ltc4162l_is_writeable_reg,

> +	.volatile_reg	= ltc4162l_is_volatile_reg,

> +	.max_register	= LTC4162L_INPUT_UNDERVOLTAGE_DAC,

> +	.cache_type	= REGCACHE_RBTREE,

> +};

> +

> +static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)

> +{

> +	/* Acknowledge interrupt to chip by clearing all events */

> +	regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);

> +	regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);

> +	regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);

> +}

> +

> +static int ltc4162l_probe(struct i2c_client *client,

> +			const struct i2c_device_id *id)

> +{

> +	struct i2c_adapter *adapter = client->adapter;

> +	struct device *dev = &client->dev;

> +	struct ltc4162l_info *info;

> +	struct power_supply_config ltc4162l_config = {};

> +	u32 value;

> +	int ret;

> +

> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {

> +		dev_err(dev, "No support for SMBUS_WORD_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, &ltc4162l_regmap_config);

> +	if (IS_ERR(info->regmap)) {

> +		dev_err(dev, "Failed to initialize register map\n");

> +		return PTR_ERR(info->regmap);

> +	}

> +

> +	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",

> +				       &info->rsnsb);

> +	if (ret) {

> +		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");

> +		return ret;

> +	}

> +	if (!info->rsnsb)

> +		return -EINVAL;

> +

> +	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",

> +				       &info->rsnsi);

> +	if (ret) {

> +		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");

> +		return ret;

> +	}

> +	if (!info->rsnsi)

> +		return -EINVAL;

> +

> +	if (!device_property_read_u32(dev, "lltc,cell-count", &value))

> +		info->cell_count = value;

> +

> +	ltc4162l_config.of_node = dev->of_node;

> +	ltc4162l_config.drv_data = info;

> +

> +	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,

> +						   &ltc4162l_config);

> +	if (IS_ERR(info->charger)) {

> +		dev_err(dev, "Failed to register charger\n");

> +		return PTR_ERR(info->charger);

> +	}

> +

> +	ret = sysfs_create_group(&info->charger->dev.kobj,

> +				 &ltc4162l_attr_group);

> +	if (ret)

> +		dev_err(dev, "failed to create extra sysfs entries\n");


please use '.attr_grp' in ltc4162l_config, which means the
attributes are registered together with the power-supply
device avoiding a udev race condition. The change also
simplifies the driver code, since (de)registration happens
automatically :)

> +	/* Disable the threshold alerts, we're not using them */

> +	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);

> +

> +	/* Enable interrupts on all status changes */

> +	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,

> +		     0x1fff);

> +	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);

> +

> +	ltc4162l_clear_interrupts(info);

> +

> +	return 0;

> +}

> +

> +static int ltc4162l_remove(struct i2c_client *client)

> +{

> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

> +

> +	sysfs_remove_group(&info->charger->dev.kobj, &ltc4162l_attr_group);

> +

> +	return 0;

> +}

> +

> +static void ltc4162l_alert(struct i2c_client *client,

> +			   enum i2c_alert_protocol type, unsigned int flag)

> +{

> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

> +

> +	if (type != I2C_PROTOCOL_SMBUS_ALERT)

> +		return;

> +

> +	ltc4162l_clear_interrupts(info);

> +	power_supply_changed(info->charger);

> +}

> +

> +static const struct i2c_device_id ltc4162l_i2c_id_table[] = {

> +	{ "ltc4162-l", 0 },

> +	{ },

> +};

> +MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);

> +

> +static const struct of_device_id ltc4162l_of_match[] = {

> +	{ .compatible = "lltc,ltc4162-l", },

> +	{ },

> +};

> +MODULE_DEVICE_TABLE(of, ltc4162l_of_match);

> +

> +static struct i2c_driver ltc4162l_driver = {

> +	.probe		= ltc4162l_probe,

> +	.remove		= ltc4162l_remove,

> +	.alert		= ltc4162l_alert,

> +	.id_table	= ltc4162l_i2c_id_table,

> +	.driver = {

> +		.name		= "ltc4162-l-charger",

> +		.of_match_table	= of_match_ptr(ltc4162l_of_match),

> +	},

> +};

> +module_i2c_driver(ltc4162l_driver);

> +

> +MODULE_LICENSE("GPL");

> +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");

> +MODULE_DESCRIPTION("LTC4162-L charger driver");


Otherwise LGTM. Please send bindings and driver as a series next
time :)

Thanks,

-- Sebastian
Mike Looijmans Jan. 4, 2021, 10:39 a.m. UTC | #3
Hello,

No worries on processing time. Only drawback is that since the project 
ended, I may no longer have access to the actual hardware for testing.

Further inline comments below.


Met vriendelijke groet / kind regards,

Mike Looijmans
System Expert


TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands

T: +31 (0) 499 33 69 69
E: mike.looijmans@topicproducts.com
W: www.topicproducts.com

Please consider the environment before printing this e-mail
On 29-12-2020 15:57, Sebastian Reichel wrote:
> Hi,

>

> Sorry for slow processing of this. Driver looks mostly fine, but I

> do have some comments.

>

> On Mon, Nov 02, 2020 at 10:21:31AM +0100, Mike Looijmans wrote:

>> Add support for the LTC4162-L Li-Ion battery charger. The driver allows

>> reading back telemetry and to set some charging options like the input

>> current limit.

>>

>> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>

>> ---

>> v2: Use microohm units instead of milliohm

>>      Add interrupt support using smbalert

>>      Support obtaining cell-count from devicetree

>> v3: Fix overflows in calculations involving resistor values

>> resent, mail bounced

>>

>>   drivers/power/supply/Kconfig             |   8 +

>>   drivers/power/supply/Makefile            |   1 +

>>   drivers/power/supply/ltc4162-l-charger.c | 898 +++++++++++++++++++++++

>>   3 files changed, 907 insertions(+)

>>   create mode 100644 drivers/power/supply/ltc4162-l-charger.c

>>

>> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig

>> index eec646c568b7..23000976cb42 100644

>> --- a/drivers/power/supply/Kconfig

>> +++ b/drivers/power/supply/Kconfig

>> @@ -513,6 +513,14 @@ config CHARGER_LT3651

>>   	  Say Y to include support for the Analog Devices (Linear Technology)

>>   	  LT3651 battery charger which reports its status via GPIO lines.

>>   

>> +config CHARGER_LTC4162L

>> +	tristate "LTC4162-L charger"

>> +	depends on I2C

>> +	select REGMAP_I2C

>> +	help

>> +	  Say Y to include support for the Analog Devices (Linear Technology)

>> +	  LTC4162-L battery charger connected to I2C.

>> +

>>   config CHARGER_MAX14577

>>   	tristate "Maxim MAX14577/77836 battery charger driver"

>>   	depends on MFD_MAX14577

>> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile

>> index dd4b86318cd9..17b1cf921c44 100644

>> --- a/drivers/power/supply/Makefile

>> +++ b/drivers/power/supply/Makefile

>> @@ -70,6 +70,7 @@ obj-$(CONFIG_CHARGER_LP8788)	+= lp8788-charger.o

>>   obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o

>>   obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o

>>   obj-$(CONFIG_CHARGER_LT3651)	+= lt3651-charger.o

>> +obj-$(CONFIG_CHARGER_LTC4162L)	+= ltc4162-l-charger.o

>>   obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o

>>   obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o

>>   obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o

>> diff --git a/drivers/power/supply/ltc4162-l-charger.c b/drivers/power/supply/ltc4162-l-charger.c

>> new file mode 100644

>> index 000000000000..b2f666113125

>> --- /dev/null

>> +++ b/drivers/power/supply/ltc4162-l-charger.c

>> @@ -0,0 +1,898 @@

>> +// SPDX-License-Identifier: GPL-2.0-or-later

>> +/*

>> + *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.

>> + *  Copyright (C) 2020, Topic Embedded Products

>> + */

>> +

>> +#include <linux/module.h>

>> +#include <linux/delay.h>

>> +#include <linux/of_device.h>

>> +#include <linux/pm_runtime.h>

>> +#include <linux/power_supply.h>

>> +#include <linux/i2c.h>

>> +#include <linux/regmap.h>

>> +

>> +/* Registers (names based on what datasheet uses) */

>> +#define LTC4162L_EN_LIMIT_ALERTS_REG		0x0D

>> +#define LTC4162L_EN_CHARGER_STATE_ALERTS_REG	0x0E

>> +#define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG	0x0F

>> +#define LTC4162L_CONFIG_BITS_REG		0x14

>> +#define LTC4162L_IIN_LIMIT_TARGET		0x15

>> +#define LTC4162L_ARM_SHIP_MODE			0x19

>> +#define LTC4162L_CHARGE_CURRENT_SETTING		0X1A

>> +#define LTC4162L_VCHARGE_SETTING		0X1B

>> +#define LTC4162L_C_OVER_X_THRESHOLD		0x1C

>> +#define LTC4162L_MAX_CV_TIME			0X1D

>> +#define LTC4162L_MAX_CHARGE_TIME		0X1E

>> +#define LTC4162L_CHARGER_CONFIG_BITS		0x29

>> +#define LTC4162L_CHARGER_STATE			0x34

>> +#define LTC4162L_CHARGE_STATUS			0x35

>> +#define LTC4162L_LIMIT_ALERTS_REG		0x36

>> +#define LTC4162L_CHARGER_STATE_ALERTS_REG	0x37

>> +#define LTC4162L_CHARGE_STATUS_ALERTS_REG	0x38

>> +#define LTC4162L_SYSTEM_STATUS_REG		0x39

>> +#define LTC4162L_VBAT				0x3A

>> +#define LTC4162L_VIN				0x3B

>> +#define LTC4162L_VOUT				0x3C

>> +#define LTC4162L_IBAT				0x3D

>> +#define LTC4162L_IIN				0x3E

>> +#define LTC4162L_DIE_TEMPERATURE		0x3F

>> +#define LTC4162L_THERMISTOR_VOLTAGE		0x40

>> +#define LTC4162L_BSR				0x41

>> +#define LTC4162L_JEITA_REGION			0x42

>> +#define LTC4162L_CHEM_CELLS_REG			0x43

>> +#define LTC4162L_ICHARGE_DAC			0x44

>> +#define LTC4162L_VCHARGE_DAC			0x45

>> +#define LTC4162L_IIN_LIMIT_DAC			0x46

>> +#define LTC4162L_VBAT_FILT			0x47

>> +#define LTC4162L_INPUT_UNDERVOLTAGE_DAC		0x4B

>> +

>> +/* Enumeration as in datasheet. Individual bits are mutually exclusive. */

>> +enum ltc4162l_state {

>> +	battery_detection = 2048,

>> +	charger_suspended = 256,

>> +	precharge = 128,   /* trickle on low bat voltage */

>> +	cc_cv_charge = 64, /* normal charge */

>> +	ntc_pause = 32,

>> +	timer_term = 16,

>> +	c_over_x_term = 8, /* battery is full */

>> +	max_charge_time_fault = 4,

>> +	bat_missing_fault = 2,

>> +	bat_short_fault = 1

>> +};

>> +

>> +/* Individual bits are mutually exclusive. Only active in charging states.*/

>> +enum ltc4162l_charge_status {

>> +	ilim_reg_active = 32,

>> +	thermal_reg_active = 16,

>> +	vin_uvcl_active = 8,

>> +	iin_limit_active = 4,

>> +	constant_current = 2,

>> +	constant_voltage = 1,

>> +	charger_off = 0

>> +};

> +use BIT(0), BIT(1), ...


I'm okay with that. This was actually a copy&paste job from the 
datasheet, and though these look like bit fields, only one bit is ever 
set. So BIT(x) might be misleading in that respect. Hence I preferred 
keeping it as the datasheet listed it.

>

>> +/* Magic number to write to ARM_SHIP_MODE register */

>> +#define LTC4162L_ARM_SHIP_MODE_MAGIC 21325

>> +

>> +struct ltc4162l_info {

>> +	struct i2c_client	*client;

>> +	struct regmap		*regmap;

>> +	struct power_supply	*charger;

>> +	u32 rsnsb;	/* Series resistor that sets charge current, microOhm */

>> +	u32 rsnsi;	/* Series resistor to measure input current, microOhm */

>> +	u8 cell_count;	/* Number of connected cells, 0 while unknown */

>> +};

>> +

>> +static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)

>> +{

>> +	int ret;

>> +	unsigned int val;

>> +

>> +	/* Once read successfully */

>> +	if (info->cell_count)

>> +		return info->cell_count;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);

>> +	if (ret)

>> +		return 0;

>> +

>> +	/* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */

>> +	val &= 0x0f;

>> +	if (!val)

>> +		return 0;

>> +

>> +	/* Once determined, keep the value */

>> +	info->cell_count = val;

>> +

>> +	return val;

>> +};

>> +

>> +/* Convert enum value to POWER_SUPPLY_STATUS value */

>> +static int ltc4162l_state_decode(enum ltc4162l_state value)

>> +{

>> +	switch (value) {

>> +	case precharge:

>> +	case cc_cv_charge:

>> +		return POWER_SUPPLY_STATUS_CHARGING;

>> +	case c_over_x_term:

>> +		return POWER_SUPPLY_STATUS_FULL;

>> +	case bat_missing_fault:

>> +	case bat_short_fault:

>> +		return POWER_SUPPLY_STATUS_UNKNOWN;

>> +	default:

>> +		return POWER_SUPPLY_STATUS_NOT_CHARGING;

>> +	}

>> +};

>> +

>> +static int ltc4162l_get_status(struct ltc4162l_info *info,

>> +			       union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

>> +	if (ret) {

>> +		dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");

>> +		return ret;

>> +	}

>> +

>> +	val->intval = ltc4162l_state_decode(regval);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)

>> +{

>> +	if (!value)

>> +		return POWER_SUPPLY_CHARGE_TYPE_NONE;

>> +

>> +	/* constant voltage/current and input_current limit are "fast" modes */

>> +	if (value <= iin_limit_active)

>> +		return POWER_SUPPLY_CHARGE_TYPE_FAST;

>> +

>> +	/* Anything that's not fast we'll return as trickle */

>> +	return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

>> +}

>> +

>> +static int ltc4162l_get_charge_type(struct ltc4162l_info *info,

>> +				    union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	val->intval = ltc4162l_charge_status_decode(regval);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_state_to_health(enum ltc4162l_state value)

>> +{

>> +	switch (value) {

>> +	case ntc_pause:

>> +		return POWER_SUPPLY_HEALTH_OVERHEAT;

>> +	case timer_term:

>> +		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;

>> +	case max_charge_time_fault:

>> +		return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;

>> +	case bat_missing_fault:

>> +		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;

>> +	case bat_short_fault:

>> +		return POWER_SUPPLY_HEALTH_DEAD;

>> +	default:

>> +		return POWER_SUPPLY_HEALTH_GOOD;

>> +	}

>> +}

>> +

>> +static int ltc4162l_get_health(struct ltc4162l_info *info,

>> +			       union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	val->intval = ltc4162l_state_to_health(regval);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_get_online(struct ltc4162l_info *info,

>> +			       union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* BIT(2) indicates if input voltage is sufficient to charge */

>> +	val->intval = !!(regval & BIT(2));

>> +

>> +	return 0;

>> +}

>> +

>> +

>> +static int ltc4162l_get_vbat(struct ltc4162l_info *info,

>> +				  unsigned int reg,

>> +				  union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, reg, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* cell_count × 192.4μV/LSB */

>> +	regval *= 1924;

>> +	regval *= ltc4162l_get_cell_count(info);

>> +	regval /= 10;

>> +	val->intval = regval;

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_get_ibat(struct ltc4162l_info *info,

>> +			     union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */

>> +	ret = (s16)(regval & 0xFFFF);

>> +	val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_get_icharge(struct ltc4162l_info *info,

>> +				unsigned int reg,

>> +				union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, reg, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

>> +

>> +	/* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */

>> +	++regval;

>> +	val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_set_icharge(struct ltc4162l_info *info,

>> +				unsigned int reg,

>> +				unsigned int value)

>> +{

>> +	value = mult_frac(value, info->rsnsb, 100000u);

>> +	value /= 10000u;

>> +

>> +	/* Round to lowest possible */

>> +	if (value)

>> +		--value;

>> +

>> +	if (value > 31)

>> +		return -EINVAL;

>> +

>> +	return regmap_write(info->regmap, reg, value);

>> +}

>> +

>> +

>> +static int ltc4162l_get_vcharge(struct ltc4162l_info *info,

>> +				unsigned int reg,

>> +				union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +	u32 voltage;

>> +

>> +	ret = regmap_read(info->regmap, reg, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	regval &= BIT(6) - 1; /* Only the lower 5 bits */

>> +

>> +	/*

>> +	 * charge voltage setting can be computed from

>> +	 * cell_count × (vcharge_setting × 12.5mV + 3.8125V)

>> +	 * where vcharge_setting ranges from 0 to 31 (4.2V max).

>> +	 */

>> +	voltage = 3812500 + (regval * 12500);

>> +	voltage *= ltc4162l_get_cell_count(info);

>> +	val->intval = voltage;

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_set_vcharge(struct ltc4162l_info *info,

>> +				unsigned int reg,

>> +				unsigned int value)

>> +{

>> +	u8 cell_count = ltc4162l_get_cell_count(info);

>> +

>> +	if (!cell_count)

>> +		return -EBUSY; /* Not available yet, try again later */

>> +

>> +	value /= cell_count;

>> +

>> +	if (value < 3812500)

>> +		return -EINVAL;

>> +

>> +	value -= 3812500;

>> +	value /= 12500;

>> +

>> +	if (value > 31)

>> +		return -EINVAL;

>> +

>> +	return regmap_write(info->regmap, reg, value);

>> +}

>> +

>> +static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,

>> +				     union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	regval &= BIT(6) - 1; /* Only 6 bits */

>> +

>> +	/* (iin_limit_dac + 1) × 500μV / RSNSI */

>> +	++regval;

>> +	regval *= 5000000u;

>> +	regval /= info->rsnsi;

>> +	val->intval = 100u * regval;

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,

>> +				  unsigned int value)

>> +{

>> +	unsigned int regval;

>> +

>> +	regval = mult_frac(value, info->rsnsi, 50000u);

>> +	regval /= 10000u;

>> +	if (regval)

>> +		--regval;

>> +	if (regval > 63)

>> +		regval = 63;

>> +

>> +	return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);

>> +}

>> +

>> +static int ltc4162l_get_die_temp(struct ltc4162l_info *info,

>> +				 union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* die_temp × 0.0215°C/LSB - 264.4°C */

>> +	ret = (s16)(regval & 0xFFFF);

>> +	ret *= 215;

>> +	ret /= 100; /* Centidegrees scale */

>> +	ret -= 26440;

>> +	val->intval = ret;

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_get_term_current(struct ltc4162l_info *info,

>> +				     union power_supply_propval *val)

>> +{

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* Check if C_OVER_X_THRESHOLD is enabled */

>> +	if (!(regval & BIT(2))) {

>> +		val->intval = 0;

>> +		return 0;

>> +	}

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* 1.466μV / RSNSB amperes/LSB */

>> +	regval *= 14660u;

>> +	regval /= info->rsnsb;

>> +	val->intval = 100 * regval;

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_set_term_current(struct ltc4162l_info *info,

>> +				     unsigned int value)

>> +{

>> +	int ret;

>> +	unsigned int regval;

>> +

>> +	if (!value) {

>> +		/* Disable en_c_over_x_term when set to zero */

>> +		return regmap_update_bits(info->regmap,

>> +					  LTC4162L_CHARGER_CONFIG_BITS,

>> +					  BIT(2), 0);

>> +	}

>> +

>> +	regval = mult_frac(value, info->rsnsb, 14660u);

>> +	regval /= 100u;

>> +

>> +	ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* Set en_c_over_x_term after changing the threshold value */

>> +	return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,

>> +				  BIT(2), BIT(2));

>> +}

>> +

>> +/* Custom properties */

>> +static const char * const ltc4162l_charge_status_name[] = {

>> +	"ilim_reg_active", /* 32 */

>> +	"thermal_reg_active",

>> +	"vin_uvcl_active",

>> +	"iin_limit_active",

>> +	"constant_current",

>> +	"constant_voltage",

>> +	"charger_off" /* 0 */

>> +};

>> +

>> +static ssize_t charge_status_show(struct device *dev,

>> +				  struct device_attribute *attr, char *buf)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	const char *result = ltc4162l_charge_status_name[

>> +				ARRAY_SIZE(ltc4162l_charge_status_name) - 1];

>> +	unsigned int regval;

>> +	unsigned int mask;

>> +	unsigned int index;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* Only one bit is set according to datasheet, let's be safe here */

>> +	for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {

>> +		if (regval & mask) {

>> +			result = ltc4162l_charge_status_name[index];

>> +			break;

>> +		}

>> +	}

>> +

>> +	return sprintf(buf, "%s\n", result);

>> +}

>> +static DEVICE_ATTR_RO(charge_status);

>> +

>> +static ssize_t input_voltage_show(struct device *dev,

>> +				  struct device_attribute *attr, char *buf)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* 1.649mV/LSB */

>> +	regval *= 1694;

>> +

>> +	return sprintf(buf, "%u\n", regval);

>> +}

>> +static DEVICE_ATTR_RO(input_voltage);

>> +

>> +static ssize_t input_current_show(struct device *dev,

>> +				  struct device_attribute *attr, char *buf)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	/* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */

>> +	ret = (s16)(regval & 0xFFFF);

>> +	ret *= 14660;

>> +	ret /= info->rsnsi;

>> +	ret *= 100;

>> +

>> +	return sprintf(buf, "%d\n", ret);

>> +}

>> +static DEVICE_ATTR_RO(input_current);

>> +

>> +static ssize_t force_telemetry_show(struct device *dev,

>> +				    struct device_attribute *attr, char *buf)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);

>> +}

>> +

>> +static ssize_t force_telemetry_store(struct device *dev,

>> +	struct device_attribute *attr,

>> +	const char *buf,

>> +	size_t count)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	int ret;

>> +	unsigned int value;

>> +

>> +	ret = kstrtouint(buf, 0, &value);

>> +	if (ret < 0)

>> +		return ret;

>> +

>> +	ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,

>> +				 BIT(2), value ? BIT(2) : 0);

>> +	if (ret < 0)

>> +		return ret;

>> +

>> +	return count;

>> +}

>> +

>> +static DEVICE_ATTR_RW(force_telemetry);

>> +

>> +static ssize_t arm_ship_mode_show(struct device *dev,

>> +				    struct device_attribute *attr, char *buf)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	unsigned int regval;

>> +	int ret;

>> +

>> +	ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);

>> +	if (ret)

>> +		return ret;

>> +

>> +	return sprintf(buf, "%u\n",

>> +		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);

>> +}

>> +

>> +static ssize_t arm_ship_mode_store(struct device *dev,

>> +	struct device_attribute *attr,

>> +	const char *buf,

>> +	size_t count)

>> +{

>> +	struct power_supply *psy = to_power_supply(dev);

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +	int ret;

>> +	unsigned int value;

>> +

>> +	ret = kstrtouint(buf, 0, &value);

>> +	if (ret < 0)

>> +		return ret;

>> +

>> +	ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,

>> +				value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);

>> +	if (ret < 0)

>> +		return ret;

>> +

>> +	return count;

>> +}

>> +

>> +static DEVICE_ATTR_RW(arm_ship_mode);

>> +

>> +static struct attribute *ltc4162l_sysfs_entries[] = {

>> +	&dev_attr_charge_status.attr,

>> +	&dev_attr_input_voltage.attr,

>> +	&dev_attr_input_current.attr,

>> +	&dev_attr_force_telemetry.attr,

>> +	&dev_attr_arm_ship_mode.attr,

>> +	NULL,

>> +};

>> +

>> +static struct attribute_group ltc4162l_attr_group = {

>> +	.name	= NULL,	/* put in device directory */

>> +	.attrs	= ltc4162l_sysfs_entries,

>> +};

>> +

>> +static int ltc4162l_get_property(struct power_supply *psy,

>> +				 enum power_supply_property psp,

>> +				 union power_supply_propval *val)

>> +{

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +

>> +	switch (psp) {

>> +	case POWER_SUPPLY_PROP_STATUS:

>> +		return ltc4162l_get_status(info, val);

>> +	case POWER_SUPPLY_PROP_CHARGE_TYPE:

>> +		return ltc4162l_get_charge_type(info, val);

>> +	case POWER_SUPPLY_PROP_HEALTH:

>> +		return ltc4162l_get_health(info, val);

>> +	case POWER_SUPPLY_PROP_ONLINE:

>> +		return ltc4162l_get_online(info, val);

>> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:

>> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT, val);

>> +	case POWER_SUPPLY_PROP_VOLTAGE_AVG:

>> +		return ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, val);

>> +	case POWER_SUPPLY_PROP_CURRENT_NOW:

>> +		return ltc4162l_get_ibat(info, val);

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:

>> +		return ltc4162l_get_icharge(info,

>> +				LTC4162L_ICHARGE_DAC, val);

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

>> +		return ltc4162l_get_icharge(info,

>> +				LTC4162L_CHARGE_CURRENT_SETTING, val);

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:

>> +		return ltc4162l_get_vcharge(info,

>> +				LTC4162L_VCHARGE_DAC, val);

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

>> +		return ltc4162l_get_vcharge(info,

>> +				LTC4162L_VCHARGE_SETTING, val);

>> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

>> +		return ltc4162l_get_iin_limit_dac(info, val);

>> +	case POWER_SUPPLY_PROP_TEMP:

>> +		return ltc4162l_get_die_temp(info, val);

>> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

>> +		return ltc4162l_get_term_current(info, val);

>> +	default:

>> +		return -EINVAL;

>> +	}

>> +}

>> +

>> +static int ltc4162l_set_property(struct power_supply *psy,

>> +					 enum power_supply_property psp,

>> +					 const union power_supply_propval *val)

>> +{

>> +	struct ltc4162l_info *info = power_supply_get_drvdata(psy);

>> +

>> +	switch (psp) {

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

>> +		return ltc4162l_set_icharge(info,

>> +				LTC4162L_CHARGE_CURRENT_SETTING, val->intval);

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

>> +		return ltc4162l_set_vcharge(info,

>> +				LTC4162L_VCHARGE_SETTING, val->intval);

>> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

>> +		return ltc4162l_set_iin_limit(info, val->intval);

>> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

>> +		return ltc4162l_set_term_current(info, val->intval);

>> +	default:

>> +		return -EINVAL;

>> +	}

>> +}

>> +

>> +static int ltc4162l_property_is_writeable(struct power_supply *psy,

>> +						enum power_supply_property psp)

>> +{

>> +	switch (psp) {

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:

>> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:

>> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:

>> +	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:

>> +		return 1;

>> +	default:

>> +		return 0;

>> +	}

>> +}

>> +

>> +/* Charger power supply property routines */

>> +static enum power_supply_property ltc4162l_properties[] = {

>> +	POWER_SUPPLY_PROP_STATUS,

>> +	POWER_SUPPLY_PROP_CHARGE_TYPE,

>> +	POWER_SUPPLY_PROP_HEALTH,

>> +	POWER_SUPPLY_PROP_ONLINE,

>> +	POWER_SUPPLY_PROP_VOLTAGE_NOW, /* Reports battery voltage */

>> +	POWER_SUPPLY_PROP_VOLTAGE_AVG,

>> +	POWER_SUPPLY_PROP_CURRENT_NOW, /* Reports battery current */

> above 3 properties should describe input voltage/current for chargers,

> see Documentation/ABI/testing/sysfs-class-power

>

> Battery IBAT and VBAT can currently only be reported from

> POWER_SUPPLY_TYPE_BATTERY.


So what should I do? Change the reported type to battery? Or make ibat 
ad vbat into custom properties and report input current/voltage here 
instead?

>

>> +	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_INPUT_CURRENT_LIMIT,

>> +	POWER_SUPPLY_PROP_TEMP,

>> +	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,

>> +};

>> +

>> +static const struct power_supply_desc ltc4162l_desc = {

>> +	.name		= "ltc4162-l",

>> +	.type		= POWER_SUPPLY_TYPE_MAINS,

>> +	.properties	= ltc4162l_properties,

>> +	.num_properties	= ARRAY_SIZE(ltc4162l_properties),

>> +	.get_property	= ltc4162l_get_property,

>> +	.set_property	= ltc4162l_set_property,

>> +	.property_is_writeable = ltc4162l_property_is_writeable,

>> +};

>> +

>> +static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)

>> +{

>> +	/* all registers up to this one are writeable */

>> +	if (reg <= LTC4162L_CHARGER_CONFIG_BITS)

>> +		return true;

>> +

>> +	/* The ALERTS registers can be written to clear alerts */

>> +	if (reg >= LTC4162L_LIMIT_ALERTS_REG &&

>> +	    reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)

>> +		return true;

>> +

>> +	return false;

>> +}

>> +

>> +static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)

>> +{

>> +	/* all registers after this one are read-only status registers */

>> +	return reg > LTC4162L_CHARGER_CONFIG_BITS;

>> +}

>> +

>> +static const struct regmap_config ltc4162l_regmap_config = {

>> +	.reg_bits	= 8,

>> +	.val_bits	= 16,

>> +	.val_format_endian = REGMAP_ENDIAN_LITTLE,

>> +	.writeable_reg	= ltc4162l_is_writeable_reg,

>> +	.volatile_reg	= ltc4162l_is_volatile_reg,

>> +	.max_register	= LTC4162L_INPUT_UNDERVOLTAGE_DAC,

>> +	.cache_type	= REGCACHE_RBTREE,

>> +};

>> +

>> +static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)

>> +{

>> +	/* Acknowledge interrupt to chip by clearing all events */

>> +	regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);

>> +	regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);

>> +	regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);

>> +}

>> +

>> +static int ltc4162l_probe(struct i2c_client *client,

>> +			const struct i2c_device_id *id)

>> +{

>> +	struct i2c_adapter *adapter = client->adapter;

>> +	struct device *dev = &client->dev;

>> +	struct ltc4162l_info *info;

>> +	struct power_supply_config ltc4162l_config = {};

>> +	u32 value;

>> +	int ret;

>> +

>> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {

>> +		dev_err(dev, "No support for SMBUS_WORD_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, &ltc4162l_regmap_config);

>> +	if (IS_ERR(info->regmap)) {

>> +		dev_err(dev, "Failed to initialize register map\n");

>> +		return PTR_ERR(info->regmap);

>> +	}

>> +

>> +	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",

>> +				       &info->rsnsb);

>> +	if (ret) {

>> +		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");

>> +		return ret;

>> +	}

>> +	if (!info->rsnsb)

>> +		return -EINVAL;

>> +

>> +	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",

>> +				       &info->rsnsi);

>> +	if (ret) {

>> +		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");

>> +		return ret;

>> +	}

>> +	if (!info->rsnsi)

>> +		return -EINVAL;

>> +

>> +	if (!device_property_read_u32(dev, "lltc,cell-count", &value))

>> +		info->cell_count = value;

>> +

>> +	ltc4162l_config.of_node = dev->of_node;

>> +	ltc4162l_config.drv_data = info;

>> +

>> +	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,

>> +						   &ltc4162l_config);

>> +	if (IS_ERR(info->charger)) {

>> +		dev_err(dev, "Failed to register charger\n");

>> +		return PTR_ERR(info->charger);

>> +	}

>> +

>> +	ret = sysfs_create_group(&info->charger->dev.kobj,

>> +				 &ltc4162l_attr_group);

>> +	if (ret)

>> +		dev_err(dev, "failed to create extra sysfs entries\n");

> please use '.attr_grp' in ltc4162l_config, which means the

> attributes are registered together with the power-supply

> device avoiding a udev race condition. The change also

> simplifies the driver code, since (de)registration happens

> automatically :)


Good tip, missed that.


>

>> +	/* Disable the threshold alerts, we're not using them */

>> +	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);

>> +

>> +	/* Enable interrupts on all status changes */

>> +	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,

>> +		     0x1fff);

>> +	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);

>> +

>> +	ltc4162l_clear_interrupts(info);

>> +

>> +	return 0;

>> +}

>> +

>> +static int ltc4162l_remove(struct i2c_client *client)

>> +{

>> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

>> +

>> +	sysfs_remove_group(&info->charger->dev.kobj, &ltc4162l_attr_group);

>> +

>> +	return 0;

>> +}

>> +

>> +static void ltc4162l_alert(struct i2c_client *client,

>> +			   enum i2c_alert_protocol type, unsigned int flag)

>> +{

>> +	struct ltc4162l_info *info = i2c_get_clientdata(client);

>> +

>> +	if (type != I2C_PROTOCOL_SMBUS_ALERT)

>> +		return;

>> +

>> +	ltc4162l_clear_interrupts(info);

>> +	power_supply_changed(info->charger);

>> +}

>> +

>> +static const struct i2c_device_id ltc4162l_i2c_id_table[] = {

>> +	{ "ltc4162-l", 0 },

>> +	{ },

>> +};

>> +MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);

>> +

>> +static const struct of_device_id ltc4162l_of_match[] = {

>> +	{ .compatible = "lltc,ltc4162-l", },

>> +	{ },

>> +};

>> +MODULE_DEVICE_TABLE(of, ltc4162l_of_match);

>> +

>> +static struct i2c_driver ltc4162l_driver = {

>> +	.probe		= ltc4162l_probe,

>> +	.remove		= ltc4162l_remove,

>> +	.alert		= ltc4162l_alert,

>> +	.id_table	= ltc4162l_i2c_id_table,

>> +	.driver = {

>> +		.name		= "ltc4162-l-charger",

>> +		.of_match_table	= of_match_ptr(ltc4162l_of_match),

>> +	},

>> +};

>> +module_i2c_driver(ltc4162l_driver);

>> +

>> +MODULE_LICENSE("GPL");

>> +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");

>> +MODULE_DESCRIPTION("LTC4162-L charger driver");

> Otherwise LGTM. Please send bindings and driver as a series next

> time :)

>

> Thanks,

>

> -- Sebastian



-- 
Mike Looijmans
diff mbox series

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index eec646c568b7..23000976cb42 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -513,6 +513,14 @@  config CHARGER_LT3651
 	  Say Y to include support for the Analog Devices (Linear Technology)
 	  LT3651 battery charger which reports its status via GPIO lines.
 
+config CHARGER_LTC4162L
+	tristate "LTC4162-L charger"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y to include support for the Analog Devices (Linear Technology)
+	  LTC4162-L battery charger connected to I2C.
+
 config CHARGER_MAX14577
 	tristate "Maxim MAX14577/77836 battery charger driver"
 	depends on MFD_MAX14577
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index dd4b86318cd9..17b1cf921c44 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -70,6 +70,7 @@  obj-$(CONFIG_CHARGER_LP8788)	+= lp8788-charger.o
 obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o
 obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o
 obj-$(CONFIG_CHARGER_LT3651)	+= lt3651-charger.o
+obj-$(CONFIG_CHARGER_LTC4162L)	+= ltc4162-l-charger.o
 obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o
 obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o
 obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o
diff --git a/drivers/power/supply/ltc4162-l-charger.c b/drivers/power/supply/ltc4162-l-charger.c
new file mode 100644
index 000000000000..b2f666113125
--- /dev/null
+++ b/drivers/power/supply/ltc4162-l-charger.c
@@ -0,0 +1,898 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for Analog Devices (Linear Technology) LTC4162-L charger IC.
+ *  Copyright (C) 2020, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/power_supply.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+/* Registers (names based on what datasheet uses) */
+#define LTC4162L_EN_LIMIT_ALERTS_REG		0x0D
+#define LTC4162L_EN_CHARGER_STATE_ALERTS_REG	0x0E
+#define LTC4162L_EN_CHARGE_STATUS_ALERTS_REG	0x0F
+#define LTC4162L_CONFIG_BITS_REG		0x14
+#define LTC4162L_IIN_LIMIT_TARGET		0x15
+#define LTC4162L_ARM_SHIP_MODE			0x19
+#define LTC4162L_CHARGE_CURRENT_SETTING		0X1A
+#define LTC4162L_VCHARGE_SETTING		0X1B
+#define LTC4162L_C_OVER_X_THRESHOLD		0x1C
+#define LTC4162L_MAX_CV_TIME			0X1D
+#define LTC4162L_MAX_CHARGE_TIME		0X1E
+#define LTC4162L_CHARGER_CONFIG_BITS		0x29
+#define LTC4162L_CHARGER_STATE			0x34
+#define LTC4162L_CHARGE_STATUS			0x35
+#define LTC4162L_LIMIT_ALERTS_REG		0x36
+#define LTC4162L_CHARGER_STATE_ALERTS_REG	0x37
+#define LTC4162L_CHARGE_STATUS_ALERTS_REG	0x38
+#define LTC4162L_SYSTEM_STATUS_REG		0x39
+#define LTC4162L_VBAT				0x3A
+#define LTC4162L_VIN				0x3B
+#define LTC4162L_VOUT				0x3C
+#define LTC4162L_IBAT				0x3D
+#define LTC4162L_IIN				0x3E
+#define LTC4162L_DIE_TEMPERATURE		0x3F
+#define LTC4162L_THERMISTOR_VOLTAGE		0x40
+#define LTC4162L_BSR				0x41
+#define LTC4162L_JEITA_REGION			0x42
+#define LTC4162L_CHEM_CELLS_REG			0x43
+#define LTC4162L_ICHARGE_DAC			0x44
+#define LTC4162L_VCHARGE_DAC			0x45
+#define LTC4162L_IIN_LIMIT_DAC			0x46
+#define LTC4162L_VBAT_FILT			0x47
+#define LTC4162L_INPUT_UNDERVOLTAGE_DAC		0x4B
+
+/* Enumeration as in datasheet. Individual bits are mutually exclusive. */
+enum ltc4162l_state {
+	battery_detection = 2048,
+	charger_suspended = 256,
+	precharge = 128,   /* trickle on low bat voltage */
+	cc_cv_charge = 64, /* normal charge */
+	ntc_pause = 32,
+	timer_term = 16,
+	c_over_x_term = 8, /* battery is full */
+	max_charge_time_fault = 4,
+	bat_missing_fault = 2,
+	bat_short_fault = 1
+};
+
+/* Individual bits are mutually exclusive. Only active in charging states.*/
+enum ltc4162l_charge_status {
+	ilim_reg_active = 32,
+	thermal_reg_active = 16,
+	vin_uvcl_active = 8,
+	iin_limit_active = 4,
+	constant_current = 2,
+	constant_voltage = 1,
+	charger_off = 0
+};
+
+/* Magic number to write to ARM_SHIP_MODE register */
+#define LTC4162L_ARM_SHIP_MODE_MAGIC 21325
+
+struct ltc4162l_info {
+	struct i2c_client	*client;
+	struct regmap		*regmap;
+	struct power_supply	*charger;
+	u32 rsnsb;	/* Series resistor that sets charge current, microOhm */
+	u32 rsnsi;	/* Series resistor to measure input current, microOhm */
+	u8 cell_count;	/* Number of connected cells, 0 while unknown */
+};
+
+static u8 ltc4162l_get_cell_count(struct ltc4162l_info *info)
+{
+	int ret;
+	unsigned int val;
+
+	/* Once read successfully */
+	if (info->cell_count)
+		return info->cell_count;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHEM_CELLS_REG, &val);
+	if (ret)
+		return 0;
+
+	/* Lower 4 bits is the cell count, or 0 if the chip doesn't know yet */
+	val &= 0x0f;
+	if (!val)
+		return 0;
+
+	/* Once determined, keep the value */
+	info->cell_count = val;
+
+	return val;
+};
+
+/* Convert enum value to POWER_SUPPLY_STATUS value */
+static int ltc4162l_state_decode(enum ltc4162l_state value)
+{
+	switch (value) {
+	case precharge:
+	case cc_cv_charge:
+		return POWER_SUPPLY_STATUS_CHARGING;
+	case c_over_x_term:
+		return POWER_SUPPLY_STATUS_FULL;
+	case bat_missing_fault:
+	case bat_short_fault:
+		return POWER_SUPPLY_STATUS_UNKNOWN;
+	default:
+		return POWER_SUPPLY_STATUS_NOT_CHARGING;
+	}
+};
+
+static int ltc4162l_get_status(struct ltc4162l_info *info,
+			       union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
+	if (ret) {
+		dev_err(&info->client->dev, "Failed to read CHARGER_STATE\n");
+		return ret;
+	}
+
+	val->intval = ltc4162l_state_decode(regval);
+
+	return 0;
+}
+
+static int ltc4162l_charge_status_decode(enum ltc4162l_charge_status value)
+{
+	if (!value)
+		return POWER_SUPPLY_CHARGE_TYPE_NONE;
+
+	/* constant voltage/current and input_current limit are "fast" modes */
+	if (value <= iin_limit_active)
+		return POWER_SUPPLY_CHARGE_TYPE_FAST;
+
+	/* Anything that's not fast we'll return as trickle */
+	return POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+}
+
+static int ltc4162l_get_charge_type(struct ltc4162l_info *info,
+				    union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
+	if (ret)
+		return ret;
+
+	val->intval = ltc4162l_charge_status_decode(regval);
+
+	return 0;
+}
+
+static int ltc4162l_state_to_health(enum ltc4162l_state value)
+{
+	switch (value) {
+	case ntc_pause:
+		return POWER_SUPPLY_HEALTH_OVERHEAT;
+	case timer_term:
+		return POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+	case max_charge_time_fault:
+		return POWER_SUPPLY_HEALTH_WATCHDOG_TIMER_EXPIRE;
+	case bat_missing_fault:
+		return POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+	case bat_short_fault:
+		return POWER_SUPPLY_HEALTH_DEAD;
+	default:
+		return POWER_SUPPLY_HEALTH_GOOD;
+	}
+}
+
+static int ltc4162l_get_health(struct ltc4162l_info *info,
+			       union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHARGER_STATE, &regval);
+	if (ret)
+		return ret;
+
+	val->intval = ltc4162l_state_to_health(regval);
+
+	return 0;
+}
+
+static int ltc4162l_get_online(struct ltc4162l_info *info,
+			       union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_SYSTEM_STATUS_REG, &regval);
+	if (ret)
+		return ret;
+
+	/* BIT(2) indicates if input voltage is sufficient to charge */
+	val->intval = !!(regval & BIT(2));
+
+	return 0;
+}
+
+
+static int ltc4162l_get_vbat(struct ltc4162l_info *info,
+				  unsigned int reg,
+				  union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	/* cell_count × 192.4μV/LSB */
+	regval *= 1924;
+	regval *= ltc4162l_get_cell_count(info);
+	regval /= 10;
+	val->intval = regval;
+
+	return 0;
+}
+
+static int ltc4162l_get_ibat(struct ltc4162l_info *info,
+			     union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_IBAT, &regval);
+	if (ret)
+		return ret;
+
+	/* Signed 16-bit number, 1.466μV / RSNSB amperes/LSB. */
+	ret = (s16)(regval & 0xFFFF);
+	val->intval = 100 * mult_frac(ret, 14660, (int)info->rsnsb);
+
+	return 0;
+}
+
+static int ltc4162l_get_icharge(struct ltc4162l_info *info,
+				unsigned int reg,
+				union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	regval &= BIT(6) - 1; /* Only the lower 5 bits */
+
+	/* The charge current servo level: (icharge_dac + 1) × 1mV/RSNSB */
+	++regval;
+	val->intval = 10000u * mult_frac(regval, 100000u, info->rsnsb);
+
+	return 0;
+}
+
+static int ltc4162l_set_icharge(struct ltc4162l_info *info,
+				unsigned int reg,
+				unsigned int value)
+{
+	value = mult_frac(value, info->rsnsb, 100000u);
+	value /= 10000u;
+
+	/* Round to lowest possible */
+	if (value)
+		--value;
+
+	if (value > 31)
+		return -EINVAL;
+
+	return regmap_write(info->regmap, reg, value);
+}
+
+
+static int ltc4162l_get_vcharge(struct ltc4162l_info *info,
+				unsigned int reg,
+				union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+	u32 voltage;
+
+	ret = regmap_read(info->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	regval &= BIT(6) - 1; /* Only the lower 5 bits */
+
+	/*
+	 * charge voltage setting can be computed from
+	 * cell_count × (vcharge_setting × 12.5mV + 3.8125V)
+	 * where vcharge_setting ranges from 0 to 31 (4.2V max).
+	 */
+	voltage = 3812500 + (regval * 12500);
+	voltage *= ltc4162l_get_cell_count(info);
+	val->intval = voltage;
+
+	return 0;
+}
+
+static int ltc4162l_set_vcharge(struct ltc4162l_info *info,
+				unsigned int reg,
+				unsigned int value)
+{
+	u8 cell_count = ltc4162l_get_cell_count(info);
+
+	if (!cell_count)
+		return -EBUSY; /* Not available yet, try again later */
+
+	value /= cell_count;
+
+	if (value < 3812500)
+		return -EINVAL;
+
+	value -= 3812500;
+	value /= 12500;
+
+	if (value > 31)
+		return -EINVAL;
+
+	return regmap_write(info->regmap, reg, value);
+}
+
+static int ltc4162l_get_iin_limit_dac(struct ltc4162l_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_IIN_LIMIT_DAC, &regval);
+	if (ret)
+		return ret;
+
+	regval &= BIT(6) - 1; /* Only 6 bits */
+
+	/* (iin_limit_dac + 1) × 500μV / RSNSI */
+	++regval;
+	regval *= 5000000u;
+	regval /= info->rsnsi;
+	val->intval = 100u * regval;
+
+	return 0;
+}
+
+static int ltc4162l_set_iin_limit(struct ltc4162l_info *info,
+				  unsigned int value)
+{
+	unsigned int regval;
+
+	regval = mult_frac(value, info->rsnsi, 50000u);
+	regval /= 10000u;
+	if (regval)
+		--regval;
+	if (regval > 63)
+		regval = 63;
+
+	return regmap_write(info->regmap, LTC4162L_IIN_LIMIT_TARGET, regval);
+}
+
+static int ltc4162l_get_die_temp(struct ltc4162l_info *info,
+				 union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_DIE_TEMPERATURE, &regval);
+	if (ret)
+		return ret;
+
+	/* die_temp × 0.0215°C/LSB - 264.4°C */
+	ret = (s16)(regval & 0xFFFF);
+	ret *= 215;
+	ret /= 100; /* Centidegrees scale */
+	ret -= 26440;
+	val->intval = ret;
+
+	return 0;
+}
+
+static int ltc4162l_get_term_current(struct ltc4162l_info *info,
+				     union power_supply_propval *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHARGER_CONFIG_BITS, &regval);
+	if (ret)
+		return ret;
+
+	/* Check if C_OVER_X_THRESHOLD is enabled */
+	if (!(regval & BIT(2))) {
+		val->intval = 0;
+		return 0;
+	}
+
+	ret = regmap_read(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, &regval);
+	if (ret)
+		return ret;
+
+	/* 1.466μV / RSNSB amperes/LSB */
+	regval *= 14660u;
+	regval /= info->rsnsb;
+	val->intval = 100 * regval;
+
+	return 0;
+}
+
+static int ltc4162l_set_term_current(struct ltc4162l_info *info,
+				     unsigned int value)
+{
+	int ret;
+	unsigned int regval;
+
+	if (!value) {
+		/* Disable en_c_over_x_term when set to zero */
+		return regmap_update_bits(info->regmap,
+					  LTC4162L_CHARGER_CONFIG_BITS,
+					  BIT(2), 0);
+	}
+
+	regval = mult_frac(value, info->rsnsb, 14660u);
+	regval /= 100u;
+
+	ret =  regmap_write(info->regmap, LTC4162L_C_OVER_X_THRESHOLD, regval);
+	if (ret)
+		return ret;
+
+	/* Set en_c_over_x_term after changing the threshold value */
+	return regmap_update_bits(info->regmap, LTC4162L_CHARGER_CONFIG_BITS,
+				  BIT(2), BIT(2));
+}
+
+/* Custom properties */
+static const char * const ltc4162l_charge_status_name[] = {
+	"ilim_reg_active", /* 32 */
+	"thermal_reg_active",
+	"vin_uvcl_active",
+	"iin_limit_active",
+	"constant_current",
+	"constant_voltage",
+	"charger_off" /* 0 */
+};
+
+static ssize_t charge_status_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	const char *result = ltc4162l_charge_status_name[
+				ARRAY_SIZE(ltc4162l_charge_status_name) - 1];
+	unsigned int regval;
+	unsigned int mask;
+	unsigned int index;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CHARGE_STATUS, &regval);
+	if (ret)
+		return ret;
+
+	/* Only one bit is set according to datasheet, let's be safe here */
+	for (mask = 32, index = 0; mask != 0; mask >>= 1, ++index) {
+		if (regval & mask) {
+			result = ltc4162l_charge_status_name[index];
+			break;
+		}
+	}
+
+	return sprintf(buf, "%s\n", result);
+}
+static DEVICE_ATTR_RO(charge_status);
+
+static ssize_t input_voltage_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_VIN, &regval);
+	if (ret)
+		return ret;
+
+	/* 1.649mV/LSB */
+	regval *= 1694;
+
+	return sprintf(buf, "%u\n", regval);
+}
+static DEVICE_ATTR_RO(input_voltage);
+
+static ssize_t input_current_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_IIN, &regval);
+	if (ret)
+		return ret;
+
+	/* Signed 16-bit number, 1.466μV / RSNSI amperes/LSB. */
+	ret = (s16)(regval & 0xFFFF);
+	ret *= 14660;
+	ret /= info->rsnsi;
+	ret *= 100;
+
+	return sprintf(buf, "%d\n", ret);
+}
+static DEVICE_ATTR_RO(input_current);
+
+static ssize_t force_telemetry_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_CONFIG_BITS_REG, &regval);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%u\n", regval & BIT(2) ? 1 : 0);
+}
+
+static ssize_t force_telemetry_store(struct device *dev,
+	struct device_attribute *attr,
+	const char *buf,
+	size_t count)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	int ret;
+	unsigned int value;
+
+	ret = kstrtouint(buf, 0, &value);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(info->regmap, LTC4162L_CONFIG_BITS_REG,
+				 BIT(2), value ? BIT(2) : 0);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(force_telemetry);
+
+static ssize_t arm_ship_mode_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(info->regmap, LTC4162L_ARM_SHIP_MODE, &regval);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%u\n",
+		regval == LTC4162L_ARM_SHIP_MODE_MAGIC ? 1 : 0);
+}
+
+static ssize_t arm_ship_mode_store(struct device *dev,
+	struct device_attribute *attr,
+	const char *buf,
+	size_t count)
+{
+	struct power_supply *psy = to_power_supply(dev);
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+	int ret;
+	unsigned int value;
+
+	ret = kstrtouint(buf, 0, &value);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(info->regmap, LTC4162L_ARM_SHIP_MODE,
+				value ? LTC4162L_ARM_SHIP_MODE_MAGIC : 0);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(arm_ship_mode);
+
+static struct attribute *ltc4162l_sysfs_entries[] = {
+	&dev_attr_charge_status.attr,
+	&dev_attr_input_voltage.attr,
+	&dev_attr_input_current.attr,
+	&dev_attr_force_telemetry.attr,
+	&dev_attr_arm_ship_mode.attr,
+	NULL,
+};
+
+static struct attribute_group ltc4162l_attr_group = {
+	.name	= NULL,	/* put in device directory */
+	.attrs	= ltc4162l_sysfs_entries,
+};
+
+static int ltc4162l_get_property(struct power_supply *psy,
+				 enum power_supply_property psp,
+				 union power_supply_propval *val)
+{
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		return ltc4162l_get_status(info, val);
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		return ltc4162l_get_charge_type(info, val);
+	case POWER_SUPPLY_PROP_HEALTH:
+		return ltc4162l_get_health(info, val);
+	case POWER_SUPPLY_PROP_ONLINE:
+		return ltc4162l_get_online(info, val);
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		return ltc4162l_get_vbat(info, LTC4162L_VBAT, val);
+	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
+		return ltc4162l_get_vbat(info, LTC4162L_VBAT_FILT, val);
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		return ltc4162l_get_ibat(info, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		return ltc4162l_get_icharge(info,
+				LTC4162L_ICHARGE_DAC, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		return ltc4162l_get_icharge(info,
+				LTC4162L_CHARGE_CURRENT_SETTING, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+		return ltc4162l_get_vcharge(info,
+				LTC4162L_VCHARGE_DAC, val);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return ltc4162l_get_vcharge(info,
+				LTC4162L_VCHARGE_SETTING, val);
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		return ltc4162l_get_iin_limit_dac(info, val);
+	case POWER_SUPPLY_PROP_TEMP:
+		return ltc4162l_get_die_temp(info, val);
+	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		return ltc4162l_get_term_current(info, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltc4162l_set_property(struct power_supply *psy,
+					 enum power_supply_property psp,
+					 const union power_supply_propval *val)
+{
+	struct ltc4162l_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+		return ltc4162l_set_icharge(info,
+				LTC4162L_CHARGE_CURRENT_SETTING, val->intval);
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+		return ltc4162l_set_vcharge(info,
+				LTC4162L_VCHARGE_SETTING, val->intval);
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		return ltc4162l_set_iin_limit(info, val->intval);
+	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		return ltc4162l_set_term_current(info, val->intval);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltc4162l_property_is_writeable(struct power_supply *psy,
+						enum power_supply_property psp)
+{
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/* Charger power supply property routines */
+static enum power_supply_property ltc4162l_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CHARGE_TYPE,
+	POWER_SUPPLY_PROP_HEALTH,
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW, /* Reports battery voltage */
+	POWER_SUPPLY_PROP_VOLTAGE_AVG,
+	POWER_SUPPLY_PROP_CURRENT_NOW, /* Reports battery current */
+	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_INPUT_CURRENT_LIMIT,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+};
+
+static const struct power_supply_desc ltc4162l_desc = {
+	.name		= "ltc4162-l",
+	.type		= POWER_SUPPLY_TYPE_MAINS,
+	.properties	= ltc4162l_properties,
+	.num_properties	= ARRAY_SIZE(ltc4162l_properties),
+	.get_property	= ltc4162l_get_property,
+	.set_property	= ltc4162l_set_property,
+	.property_is_writeable = ltc4162l_property_is_writeable,
+};
+
+static bool ltc4162l_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	/* all registers up to this one are writeable */
+	if (reg <= LTC4162L_CHARGER_CONFIG_BITS)
+		return true;
+
+	/* The ALERTS registers can be written to clear alerts */
+	if (reg >= LTC4162L_LIMIT_ALERTS_REG &&
+	    reg <= LTC4162L_CHARGE_STATUS_ALERTS_REG)
+		return true;
+
+	return false;
+}
+
+static bool ltc4162l_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	/* all registers after this one are read-only status registers */
+	return reg > LTC4162L_CHARGER_CONFIG_BITS;
+}
+
+static const struct regmap_config ltc4162l_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 16,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+	.writeable_reg	= ltc4162l_is_writeable_reg,
+	.volatile_reg	= ltc4162l_is_volatile_reg,
+	.max_register	= LTC4162L_INPUT_UNDERVOLTAGE_DAC,
+	.cache_type	= REGCACHE_RBTREE,
+};
+
+static void ltc4162l_clear_interrupts(struct ltc4162l_info *info)
+{
+	/* Acknowledge interrupt to chip by clearing all events */
+	regmap_write(info->regmap, LTC4162L_LIMIT_ALERTS_REG, 0);
+	regmap_write(info->regmap, LTC4162L_CHARGER_STATE_ALERTS_REG, 0);
+	regmap_write(info->regmap, LTC4162L_CHARGE_STATUS_ALERTS_REG, 0);
+}
+
+static int ltc4162l_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
+	struct ltc4162l_info *info;
+	struct power_supply_config ltc4162l_config = {};
+	u32 value;
+	int ret;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_err(dev, "No support for SMBUS_WORD_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, &ltc4162l_regmap_config);
+	if (IS_ERR(info->regmap)) {
+		dev_err(dev, "Failed to initialize register map\n");
+		return PTR_ERR(info->regmap);
+	}
+
+	ret = device_property_read_u32(dev, "lltc,rsnsb-micro-ohms",
+				       &info->rsnsb);
+	if (ret) {
+		dev_err(dev, "Missing lltc,rsnsb-micro-ohms property\n");
+		return ret;
+	}
+	if (!info->rsnsb)
+		return -EINVAL;
+
+	ret = device_property_read_u32(dev, "lltc,rsnsi-micro-ohms",
+				       &info->rsnsi);
+	if (ret) {
+		dev_err(dev, "Missing lltc,rsnsi-micro-ohms property\n");
+		return ret;
+	}
+	if (!info->rsnsi)
+		return -EINVAL;
+
+	if (!device_property_read_u32(dev, "lltc,cell-count", &value))
+		info->cell_count = value;
+
+	ltc4162l_config.of_node = dev->of_node;
+	ltc4162l_config.drv_data = info;
+
+	info->charger = devm_power_supply_register(dev, &ltc4162l_desc,
+						   &ltc4162l_config);
+	if (IS_ERR(info->charger)) {
+		dev_err(dev, "Failed to register charger\n");
+		return PTR_ERR(info->charger);
+	}
+
+	ret = sysfs_create_group(&info->charger->dev.kobj,
+				 &ltc4162l_attr_group);
+	if (ret)
+		dev_err(dev, "failed to create extra sysfs entries\n");
+
+	/* Disable the threshold alerts, we're not using them */
+	regmap_write(info->regmap, LTC4162L_EN_LIMIT_ALERTS_REG, 0);
+
+	/* Enable interrupts on all status changes */
+	regmap_write(info->regmap, LTC4162L_EN_CHARGER_STATE_ALERTS_REG,
+		     0x1fff);
+	regmap_write(info->regmap, LTC4162L_EN_CHARGE_STATUS_ALERTS_REG, 0x1f);
+
+	ltc4162l_clear_interrupts(info);
+
+	return 0;
+}
+
+static int ltc4162l_remove(struct i2c_client *client)
+{
+	struct ltc4162l_info *info = i2c_get_clientdata(client);
+
+	sysfs_remove_group(&info->charger->dev.kobj, &ltc4162l_attr_group);
+
+	return 0;
+}
+
+static void ltc4162l_alert(struct i2c_client *client,
+			   enum i2c_alert_protocol type, unsigned int flag)
+{
+	struct ltc4162l_info *info = i2c_get_clientdata(client);
+
+	if (type != I2C_PROTOCOL_SMBUS_ALERT)
+		return;
+
+	ltc4162l_clear_interrupts(info);
+	power_supply_changed(info->charger);
+}
+
+static const struct i2c_device_id ltc4162l_i2c_id_table[] = {
+	{ "ltc4162-l", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, ltc4162l_i2c_id_table);
+
+static const struct of_device_id ltc4162l_of_match[] = {
+	{ .compatible = "lltc,ltc4162-l", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ltc4162l_of_match);
+
+static struct i2c_driver ltc4162l_driver = {
+	.probe		= ltc4162l_probe,
+	.remove		= ltc4162l_remove,
+	.alert		= ltc4162l_alert,
+	.id_table	= ltc4162l_i2c_id_table,
+	.driver = {
+		.name		= "ltc4162-l-charger",
+		.of_match_table	= of_match_ptr(ltc4162l_of_match),
+	},
+};
+module_i2c_driver(ltc4162l_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
+MODULE_DESCRIPTION("LTC4162-L charger driver");