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Date:   Mon, 16 Mar 2020 10:34:07 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Tobias Schramm <t.schramm@manjaro.org>
Cc:     Sebastian Reichel <sre@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Maxime Ripard <mripard@kernel.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        Heiko Stuebner <heiko.stuebner@theobroma-systems.com>,
        Stephan Gerhold <stephan@gerhold.net>,
        Mark Brown <broonie@kernel.org>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 3/3] power: supply: add CellWise cw2015 fuel gauge
 driver
Message-ID: <20200316083407.GB1922688@smile.fi.intel.com>
References: <20200315191914.118565-1-t.schramm@manjaro.org>
 <20200315191914.118565-4-t.schramm@manjaro.org>
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In-Reply-To: <20200315191914.118565-4-t.schramm@manjaro.org>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Sender: linux-kernel-owner@vger.kernel.org
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On Sun, Mar 15, 2020 at 08:19:14PM +0100, Tobias Schramm wrote:
> This patch adds a driver for the CellWise cw2015 fuel gauge.
> 
> The CellWise cw2015 is a shuntless, single-cell Li-Ion fuel gauge used
> in the pine64 Pinebook Pro laptop and some Raspberry Pi UPS HATs.
> 

From style and APIs usage point of view looks fine to me
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>


> Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
> ---
>  MAINTAINERS                           |   6 +
>  drivers/power/supply/Kconfig          |  11 +
>  drivers/power/supply/Makefile         |   1 +
>  drivers/power/supply/cw2015_battery.c | 749 ++++++++++++++++++++++++++
>  4 files changed, 767 insertions(+)
>  create mode 100644 drivers/power/supply/cw2015_battery.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a6fbdf354d34..0260c89618f9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3885,6 +3885,12 @@ F:	arch/powerpc/include/uapi/asm/spu*.h
>  F:	arch/powerpc/oprofile/*cell*
>  F:	arch/powerpc/platforms/cell/
>  
> +CELLWISE CW2015 BATTERY DRIVER
> +M:	Tobias Schrammm <t.schramm@manjaro.org>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/power/supply/cw2015_battery.yaml
> +F:	drivers/power/supply/cw2015_battery.c
> +
>  CEPH COMMON CODE (LIBCEPH)
>  M:	Ilya Dryomov <idryomov@gmail.com>
>  M:	Jeff Layton <jlayton@kernel.org>
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index 9a5591ab90d0..c8bc85906dee 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -116,6 +116,17 @@ config BATTERY_CPCAP
>  	  Say Y here to enable support for battery on Motorola
>  	  phones and tablets such as droid 4.
>  
> +config BATTERY_CW2015
> +	tristate "CW2015 Battery driver"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Say Y here to enable support for the cellwise cw2015
> +	  battery fuel gauge (used in the Pinebook Pro & others)
> +
> +	  This driver can also be built as a module. If so, the module will be
> +	  called cw2015_battery.
> +
>  config BATTERY_DS2760
>  	tristate "DS2760 battery driver (HP iPAQ & others)"
>  	depends on W1
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 6c7da920ea83..69727a10e835 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
>  obj-$(CONFIG_BATTERY_AXP20X)	+= axp20x_battery.o
>  obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
>  obj-$(CONFIG_BATTERY_CPCAP)	+= cpcap-battery.o
> +obj-$(CONFIG_BATTERY_CW2015)	+= cw2015_battery.o
>  obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
>  obj-$(CONFIG_BATTERY_DS2780)	+= ds2780_battery.o
>  obj-$(CONFIG_BATTERY_DS2781)	+= ds2781_battery.o
> diff --git a/drivers/power/supply/cw2015_battery.c b/drivers/power/supply/cw2015_battery.c
> new file mode 100644
> index 000000000000..8603da6f4593
> --- /dev/null
> +++ b/drivers/power/supply/cw2015_battery.c
> @@ -0,0 +1,749 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Fuel gauge driver for CellWise 2013 / 2015
> + *
> + * Copyright (C) 2012, RockChip
> + * Copyright (C) 2020, Tobias Schramm
> + *
> + * Authors: xuhuicong <xhc@rock-chips.com>
> + * Authors: Tobias Schramm <t.schramm@manjaro.org>
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/gfp.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/power_supply.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/time.h>
> +#include <linux/workqueue.h>
> +
> +#define CW2015_SIZE_BATINFO		64
> +
> +#define CW2015_RESET_TRIES		5
> +
> +#define CW2015_REG_VERSION		0x00
> +#define CW2015_REG_VCELL		0x02
> +#define CW2015_REG_SOC			0x04
> +#define CW2015_REG_RRT_ALERT		0x06
> +#define CW2015_REG_CONFIG		0x08
> +#define CW2015_REG_MODE			0x0A
> +#define CW2015_REG_BATINFO		0x10
> +
> +#define CW2015_MODE_SLEEP_MASK		GENMASK(7, 6)
> +#define CW2015_MODE_SLEEP		(0x03 << 6)
> +#define CW2015_MODE_NORMAL		(0x00 << 6)
> +#define CW2015_MODE_QUICK_START		(0x03 << 4)
> +#define CW2015_MODE_RESTART		(0x0f << 0)
> +
> +#define CW2015_CONFIG_UPDATE_FLG	(0x01 << 1)
> +#define CW2015_ATHD(x)			((x) << 3)
> +#define CW2015_MASK_ATHD		GENMASK(7, 3)
> +#define CW2015_MASK_SOC			GENMASK(12, 0)
> +
> +/* reset gauge of no valid state of charge could be polled for 40s */
> +#define CW2015_BAT_SOC_ERROR_MS		(40 * MSEC_PER_SEC)
> +/* reset gauge if state of charge stuck for half an hour during charging */
> +#define CW2015_BAT_CHARGING_STUCK_MS	(1800 * MSEC_PER_SEC)
> +
> +/* poll interval from CellWise GPL Android driver example */
> +#define CW2015_DEFAULT_POLL_INTERVAL_MS		8000
> +
> +#define CW2015_AVERAGING_SAMPLES		3
> +
> +struct cw_battery {
> +	struct device *dev;
> +	struct workqueue_struct *battery_workqueue;
> +	struct delayed_work battery_delay_work;
> +	struct regmap *regmap;
> +	struct power_supply *rk_bat;
> +	struct power_supply_battery_info battery;
> +	u8 *bat_profile;
> +
> +	bool charger_attached;
> +	bool battery_changed;
> +
> +	int soc;
> +	int voltage_mv;
> +	int status;
> +	int time_to_empty;
> +	int charge_count;
> +
> +	u32 poll_interval_ms;
> +	u8 alert_level;
> +
> +	unsigned int read_errors;
> +	unsigned int charge_stuck_cnt;
> +};
> +
> +static int cw_read_word(struct cw_battery *cw_bat, u8 reg, u16 *val)
> +{
> +	__be16 value;
> +	int ret;
> +
> +	ret = regmap_bulk_read(cw_bat->regmap, reg, &value, sizeof(value));
> +	if (ret)
> +		return ret;
> +
> +	*val = be16_to_cpu(value);
> +	return 0;
> +}
> +
> +int cw_update_profile(struct cw_battery *cw_bat)
> +{
> +	int ret;
> +	unsigned int reg_val;
> +	u8 reset_val;
> +
> +	/* make sure gauge is not in sleep mode */
> +	ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, &reg_val);
> +	if (ret)
> +		return ret;
> +
> +	reset_val = reg_val;
> +	if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
> +		dev_err(cw_bat->dev,
> +			"Gauge is in sleep mode, can't update battery info\n");
> +		return -EINVAL;
> +	}
> +
> +	/* write new battery info */
> +	ret = regmap_raw_write(cw_bat->regmap, CW2015_REG_BATINFO,
> +			       cw_bat->bat_profile,
> +			       CW2015_SIZE_BATINFO);
> +	if (ret)
> +		return ret;
> +
> +	/* set config update flag  */
> +	reg_val |= CW2015_CONFIG_UPDATE_FLG;
> +	reg_val &= ~CW2015_MASK_ATHD;
> +	reg_val |= CW2015_ATHD(cw_bat->alert_level);
> +	ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
> +	if (ret)
> +		return ret;
> +
> +	/* reset gauge to apply new battery profile */
> +	reset_val &= ~CW2015_MODE_RESTART;
> +	reg_val = reset_val | CW2015_MODE_RESTART;
> +	ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
> +	if (ret)
> +		return ret;
> +
> +	/* wait for gauge to reset */
> +	msleep(20);
> +
> +	/* clear reset flag */
> +	ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
> +	if (ret)
> +		return ret;
> +
> +	/* wait for gauge to become ready */
> +	ret = regmap_read_poll_timeout(cw_bat->regmap, CW2015_REG_SOC,
> +				       reg_val, reg_val <= 100,
> +				       10 * USEC_PER_MSEC, 10 * USEC_PER_SEC);
> +	if (ret)
> +		dev_err(cw_bat->dev,
> +			"Gauge did not become ready after profile upload\n");
> +	else
> +		dev_dbg(cw_bat->dev, "Battery profile updated\n");
> +
> +	return ret;
> +}
> +
> +static int cw_init(struct cw_battery *cw_bat)
> +{
> +	int ret;
> +	unsigned int reg_val = CW2015_MODE_SLEEP;
> +
> +	if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
> +		reg_val = CW2015_MODE_NORMAL;
> +		ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, &reg_val);
> +	if (ret)
> +		return ret;
> +
> +	if ((reg_val & CW2015_MASK_ATHD) != CW2015_ATHD(cw_bat->alert_level)) {
> +		dev_dbg(cw_bat->dev, "Setting new alert level\n");
> +		reg_val &= ~CW2015_MASK_ATHD;
> +		reg_val |= ~CW2015_ATHD(cw_bat->alert_level);
> +		ret = regmap_write(cw_bat->regmap, CW2015_REG_CONFIG, reg_val);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regmap_read(cw_bat->regmap, CW2015_REG_CONFIG, &reg_val);
> +	if (ret)
> +		return ret;
> +
> +	if (!(reg_val & CW2015_CONFIG_UPDATE_FLG)) {
> +		dev_dbg(cw_bat->dev,
> +			"Battery profile not present, uploading battery profile\n");
> +		if (cw_bat->bat_profile) {
> +			ret = cw_update_profile(cw_bat);
> +			if (ret) {
> +				dev_err(cw_bat->dev,
> +					"Failed to upload battery profile\n");
> +				return ret;
> +			}
> +		} else {
> +			dev_warn(cw_bat->dev,
> +				 "No profile specified, continuing without profile\n");
> +		}
> +	} else if (cw_bat->bat_profile) {
> +		u8 bat_info[CW2015_SIZE_BATINFO];
> +
> +		ret = regmap_raw_read(cw_bat->regmap, CW2015_REG_BATINFO,
> +				      bat_info, CW2015_SIZE_BATINFO);
> +		if (ret) {
> +			dev_err(cw_bat->dev,
> +				"Failed to read stored battery profile\n");
> +			return ret;
> +		}
> +
> +		if (memcmp(bat_info, cw_bat->bat_profile, CW2015_SIZE_BATINFO)) {
> +			dev_warn(cw_bat->dev, "Replacing stored battery profile\n");
> +			ret = cw_update_profile(cw_bat);
> +			if (ret)
> +				return ret;
> +		}
> +	} else {
> +		dev_warn(cw_bat->dev,
> +			 "Can't check current battery profile, no profile provided\n");
> +	}
> +
> +	dev_dbg(cw_bat->dev, "Battery profile configured\n");
> +	return 0;
> +}
> +
> +static int cw_power_on_reset(struct cw_battery *cw_bat)
> +{
> +	int ret;
> +	unsigned char reset_val;
> +
> +	reset_val = CW2015_MODE_SLEEP;
> +	ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
> +	if (ret)
> +		return ret;
> +
> +	/* wait for gauge to enter sleep */
> +	msleep(20);
> +
> +	reset_val = CW2015_MODE_NORMAL;
> +	ret = regmap_write(cw_bat->regmap, CW2015_REG_MODE, reset_val);
> +	if (ret)
> +		return ret;
> +
> +	ret = cw_init(cw_bat);
> +	if (ret)
> +		return ret;
> +	return 0;
> +}
> +
> +#define HYSTERESIS(current, previous, up, down) \
> +	(((current) < (previous) + (up)) && ((current) > (previous) - (down)))
> +
> +static int cw_get_soc(struct cw_battery *cw_bat)
> +{
> +	unsigned int soc;
> +	int ret;
> +
> +	ret = regmap_read(cw_bat->regmap, CW2015_REG_SOC, &soc);
> +	if (ret)
> +		return ret;
> +
> +	if (soc > 100) {
> +		int max_error_cycles =
> +			CW2015_BAT_SOC_ERROR_MS / cw_bat->poll_interval_ms;
> +
> +		dev_err(cw_bat->dev, "Invalid SoC %d%%\n", soc);
> +		cw_bat->read_errors++;
> +		if (cw_bat->read_errors > max_error_cycles) {
> +			dev_warn(cw_bat->dev,
> +				 "Too many invalid SoC reports, resetting gauge\n");
> +			cw_power_on_reset(cw_bat);
> +			cw_bat->read_errors = 0;
> +		}
> +		return cw_bat->soc;
> +	}
> +	cw_bat->read_errors = 0;
> +
> +	/* Reset gauge if stuck while charging */
> +	if (cw_bat->status == POWER_SUPPLY_STATUS_CHARGING && soc == cw_bat->soc) {
> +		int max_stuck_cycles =
> +			CW2015_BAT_CHARGING_STUCK_MS / cw_bat->poll_interval_ms;
> +
> +		cw_bat->charge_stuck_cnt++;
> +		if (cw_bat->charge_stuck_cnt > max_stuck_cycles) {
> +			dev_warn(cw_bat->dev,
> +				 "SoC stuck @%u%%, resetting gauge\n", soc);
> +			cw_power_on_reset(cw_bat);
> +			cw_bat->charge_stuck_cnt = 0;
> +		}
> +	} else {
> +		cw_bat->charge_stuck_cnt = 0;
> +	}
> +
> +	/* Ignore voltage dips during charge */
> +	if (cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 0, 3))
> +		soc = cw_bat->soc;
> +
> +	/* Ignore voltage spikes during discharge */
> +	if (!cw_bat->charger_attached && HYSTERESIS(soc, cw_bat->soc, 3, 0))
> +		soc = cw_bat->soc;
> +
> +	return soc;
> +}
> +
> +static int cw_get_voltage(struct cw_battery *cw_bat)
> +{
> +	int ret, i, voltage_mv;
> +	u16 reg_val;
> +	u32 avg = 0;
> +
> +	for (i = 0; i < CW2015_AVERAGING_SAMPLES; i++) {
> +		ret = cw_read_word(cw_bat, CW2015_REG_VCELL, &reg_val);
> +		if (ret)
> +			return ret;
> +
> +		avg += reg_val;
> +	}
> +	avg /= CW2015_AVERAGING_SAMPLES;
> +
> +	/*
> +	 * 305 uV per ADC step
> +	 * Use 312 / 1024  as efficient approximation of 305 / 1000
> +	 * Negligible error of 0.1%
> +	 */
> +	voltage_mv = avg * 312 / 1024;
> +
> +	dev_dbg(cw_bat->dev, "Read voltage: %d mV, raw=0x%04x\n",
> +		voltage_mv, reg_val);
> +	return voltage_mv;
> +}
> +
> +static int cw_get_time_to_empty(struct cw_battery *cw_bat)
> +{
> +	int ret;
> +	u16 value16;
> +
> +	ret = cw_read_word(cw_bat, CW2015_REG_RRT_ALERT, &value16);
> +	if (ret)
> +		return ret;
> +
> +	return value16 & CW2015_MASK_SOC;
> +}
> +
> +static void cw_update_charge_status(struct cw_battery *cw_bat)
> +{
> +	int ret;
> +
> +	ret = power_supply_am_i_supplied(cw_bat->rk_bat);
> +	if (ret < 0) {
> +		dev_warn(cw_bat->dev, "Failed to get supply state: %d\n", ret);
> +	} else {
> +		bool charger_attached;
> +
> +		charger_attached = !!ret;
> +		if (cw_bat->charger_attached != charger_attached) {
> +			cw_bat->battery_changed = true;
> +			if (charger_attached)
> +				cw_bat->charge_count++;
> +		}
> +		cw_bat->charger_attached = charger_attached;
> +	}
> +}
> +
> +static void cw_update_soc(struct cw_battery *cw_bat)
> +{
> +	int soc;
> +
> +	soc = cw_get_soc(cw_bat);
> +	if (soc < 0)
> +		dev_err(cw_bat->dev, "Failed to get SoC from gauge: %d\n", soc);
> +	else if (cw_bat->soc != soc) {
> +		cw_bat->soc = soc;
> +		cw_bat->battery_changed = true;
> +	}
> +}
> +
> +static void cw_update_voltage(struct cw_battery *cw_bat)
> +{
> +	int voltage_mv;
> +
> +	voltage_mv = cw_get_voltage(cw_bat);
> +	if (voltage_mv < 0)
> +		dev_err(cw_bat->dev, "Failed to get voltage from gauge: %d\n",
> +			voltage_mv);
> +	else
> +		cw_bat->voltage_mv = voltage_mv;
> +}
> +
> +static void cw_update_status(struct cw_battery *cw_bat)
> +{
> +	int status = POWER_SUPPLY_STATUS_DISCHARGING;
> +
> +	if (cw_bat->charger_attached) {
> +		if (cw_bat->soc >= 100)
> +			status = POWER_SUPPLY_STATUS_FULL;
> +		else
> +			status = POWER_SUPPLY_STATUS_CHARGING;
> +	}
> +
> +	if (cw_bat->status != status)
> +		cw_bat->battery_changed = true;
> +	cw_bat->status = status;
> +}
> +
> +static void cw_update_time_to_empty(struct cw_battery *cw_bat)
> +{
> +	int time_to_empty;
> +
> +	time_to_empty = cw_get_time_to_empty(cw_bat);
> +	if (time_to_empty < 0)
> +		dev_err(cw_bat->dev, "Failed to get time to empty from gauge: %d\n",
> +			time_to_empty);
> +	else if (cw_bat->time_to_empty != time_to_empty) {
> +		cw_bat->time_to_empty = time_to_empty;
> +		cw_bat->battery_changed = true;
> +	}
> +}
> +
> +static void cw_bat_work(struct work_struct *work)
> +{
> +	struct delayed_work *delay_work;
> +	struct cw_battery *cw_bat;
> +	int ret;
> +	unsigned int reg_val;
> +
> +	delay_work = to_delayed_work(work);
> +	cw_bat = container_of(delay_work, struct cw_battery, battery_delay_work);
> +	ret = regmap_read(cw_bat->regmap, CW2015_REG_MODE, &reg_val);
> +	if (ret) {
> +		dev_err(cw_bat->dev, "Failed to read mode from gauge: %d\n", ret);
> +	} else {
> +		if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
> +			int i;
> +
> +			for (i = 0; i < CW2015_RESET_TRIES; i++) {
> +				if (!cw_power_on_reset(cw_bat))
> +					break;
> +			}
> +		}
> +		cw_update_soc(cw_bat);
> +		cw_update_voltage(cw_bat);
> +		cw_update_charge_status(cw_bat);
> +		cw_update_status(cw_bat);
> +		cw_update_time_to_empty(cw_bat);
> +	}
> +	dev_dbg(cw_bat->dev, "charger_attached = %d\n", cw_bat->charger_attached);
> +	dev_dbg(cw_bat->dev, "status = %d\n", cw_bat->status);
> +	dev_dbg(cw_bat->dev, "soc = %d%%\n", cw_bat->soc);
> +	dev_dbg(cw_bat->dev, "voltage = %dmV\n", cw_bat->voltage_mv);
> +
> +	if (cw_bat->battery_changed)
> +		power_supply_changed(cw_bat->rk_bat);
> +	cw_bat->battery_changed = false;
> +
> +	queue_delayed_work(cw_bat->battery_workqueue,
> +			   &cw_bat->battery_delay_work,
> +			   msecs_to_jiffies(cw_bat->poll_interval_ms));
> +}
> +
> +static bool cw_battery_valid_time_to_empty(struct cw_battery *cw_bat)
> +{
> +	return	cw_bat->time_to_empty > 0 &&
> +		cw_bat->time_to_empty < CW2015_MASK_SOC &&
> +		cw_bat->status == POWER_SUPPLY_STATUS_DISCHARGING;
> +}
> +
> +static int cw_battery_get_property(struct power_supply *psy,
> +				   enum power_supply_property psp,
> +				   union power_supply_propval *val)
> +{
> +	struct cw_battery *cw_bat;
> +
> +	cw_bat = power_supply_get_drvdata(psy);
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CAPACITY:
> +		val->intval = cw_bat->soc;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_STATUS:
> +		val->intval = cw_bat->status;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_PRESENT:
> +		val->intval = !!cw_bat->voltage_mv;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> +		val->intval = cw_bat->voltage_mv * 1000;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
> +		if (cw_battery_valid_time_to_empty(cw_bat))
> +			val->intval = cw_bat->time_to_empty;
> +		else
> +			val->intval = 0;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_TECHNOLOGY:
> +		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
> +		val->intval = cw_bat->charge_count;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CHARGE_FULL:
> +	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> +		if (cw_bat->battery.charge_full_design_uah > 0)
> +			val->intval = cw_bat->battery.charge_full_design_uah;
> +		else
> +			val->intval = 0;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CURRENT_NOW:
> +		if (cw_battery_valid_time_to_empty(cw_bat) &&
> +		    cw_bat->battery.charge_full_design_uah > 0) {
> +			/* calculate remaining capacity */
> +			val->intval = cw_bat->battery.charge_full_design_uah;
> +			val->intval = val->intval * cw_bat->soc / 100;
> +
> +			/* estimate current based on time to empty */
> +			val->intval = 60 * val->intval / cw_bat->time_to_empty;
> +		} else {
> +			val->intval = 0;
> +		}
> +
> +		break;
> +
> +	default:
> +		break;
> +	}
> +	return 0;
> +}
> +
> +static enum power_supply_property cw_battery_properties[] = {
> +	POWER_SUPPLY_PROP_CAPACITY,
> +	POWER_SUPPLY_PROP_STATUS,
> +	POWER_SUPPLY_PROP_PRESENT,
> +	POWER_SUPPLY_PROP_VOLTAGE_NOW,
> +	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
> +	POWER_SUPPLY_PROP_TECHNOLOGY,
> +	POWER_SUPPLY_PROP_CHARGE_COUNTER,
> +	POWER_SUPPLY_PROP_CHARGE_FULL,
> +	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> +	POWER_SUPPLY_PROP_CURRENT_NOW,
> +};
> +
> +static const struct power_supply_desc cw2015_bat_desc = {
> +	.name		= "cw2015-battery",
> +	.type		= POWER_SUPPLY_TYPE_BATTERY,
> +	.properties	= cw_battery_properties,
> +	.num_properties	= ARRAY_SIZE(cw_battery_properties),
> +	.get_property	= cw_battery_get_property,
> +};
> +
> +static int cw2015_parse_properties(struct cw_battery *cw_bat)
> +{
> +	struct device *dev = cw_bat->dev;
> +	int length;
> +	int ret;
> +
> +	length = device_property_count_u8(dev, "cellwise,battery-profile");
> +	if (length < 0) {
> +		dev_warn(cw_bat->dev,
> +			 "No battery-profile found, using current flash contents\n");
> +	} else if (length != CW2015_SIZE_BATINFO) {
> +		dev_err(cw_bat->dev, "battery-profile must be %d bytes\n",
> +			CW2015_SIZE_BATINFO);
> +		return -EINVAL;
> +	} else {
> +		cw_bat->bat_profile = devm_kzalloc(dev, length, GFP_KERNEL);
> +		if (!cw_bat->bat_profile)
> +			return -ENOMEM;
> +
> +		ret = device_property_read_u8_array(dev,
> +						"cellwise,battery-profile",
> +						cw_bat->bat_profile,
> +						length);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = device_property_read_u32(dev, "cellwise,monitor-interval-ms",
> +				       &cw_bat->poll_interval_ms);
> +	if (ret) {
> +		dev_dbg(cw_bat->dev, "Using default poll interval\n");
> +		cw_bat->poll_interval_ms = CW2015_DEFAULT_POLL_INTERVAL_MS;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct regmap_range regmap_ranges_rd_yes[] = {
> +	regmap_reg_range(CW2015_REG_VERSION, CW2015_REG_VERSION),
> +	regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_CONFIG),
> +	regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
> +	regmap_reg_range(CW2015_REG_BATINFO,
> +			CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
> +};
> +
> +static const struct regmap_access_table regmap_rd_table = {
> +	.yes_ranges = regmap_ranges_rd_yes,
> +	.n_yes_ranges = 4,
> +};
> +
> +static const struct regmap_range regmap_ranges_wr_yes[] = {
> +	regmap_reg_range(CW2015_REG_RRT_ALERT, CW2015_REG_CONFIG),
> +	regmap_reg_range(CW2015_REG_MODE, CW2015_REG_MODE),
> +	regmap_reg_range(CW2015_REG_BATINFO,
> +			CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1),
> +};
> +
> +static const struct regmap_access_table regmap_wr_table = {
> +	.yes_ranges = regmap_ranges_wr_yes,
> +	.n_yes_ranges = 3,
> +};
> +
> +static const struct regmap_range regmap_ranges_vol_yes[] = {
> +	regmap_reg_range(CW2015_REG_VCELL, CW2015_REG_SOC + 1),
> +};
> +
> +static const struct regmap_access_table regmap_vol_table = {
> +	.yes_ranges = regmap_ranges_vol_yes,
> +	.n_yes_ranges = 1,
> +};
> +
> +static const struct regmap_config cw2015_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.rd_table = &regmap_rd_table,
> +	.wr_table = &regmap_wr_table,
> +	.volatile_table = &regmap_vol_table,
> +	.max_register = CW2015_REG_BATINFO + CW2015_SIZE_BATINFO - 1,
> +};
> +
> +static int cw_bat_probe(struct i2c_client *client)
> +{
> +	int ret;
> +	struct cw_battery *cw_bat;
> +	struct power_supply_config psy_cfg = { 0 };
> +
> +	cw_bat = devm_kzalloc(&client->dev, sizeof(*cw_bat), GFP_KERNEL);
> +	if (!cw_bat)
> +		return -ENOMEM;
> +
> +	i2c_set_clientdata(client, cw_bat);
> +	cw_bat->dev = &client->dev;
> +	cw_bat->soc = 1;
> +
> +	ret = cw2015_parse_properties(cw_bat);
> +	if (ret) {
> +		dev_err(cw_bat->dev, "Failed to parse cw2015 properties\n");
> +		return ret;
> +	}
> +
> +	cw_bat->regmap = devm_regmap_init_i2c(client, &cw2015_regmap_config);
> +	if (IS_ERR(cw_bat->regmap)) {
> +		dev_err(cw_bat->dev, "Failed to allocate regmap: %ld\n",
> +			PTR_ERR(cw_bat->regmap));
> +		return PTR_ERR(cw_bat->regmap);
> +	}
> +
> +	ret = cw_init(cw_bat);
> +	if (ret) {
> +		dev_err(cw_bat->dev, "Init failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +	psy_cfg.drv_data = cw_bat;
> +	psy_cfg.fwnode = dev_fwnode(cw_bat->dev);
> +
> +	cw_bat->rk_bat = devm_power_supply_register(&client->dev,
> +						    &cw2015_bat_desc,
> +						    &psy_cfg);
> +	if (IS_ERR(cw_bat->rk_bat)) {
> +		dev_err(cw_bat->dev, "Failed to register power supply\n");
> +		return PTR_ERR(cw_bat->rk_bat);
> +	}
> +
> +	ret = power_supply_get_battery_info(cw_bat->rk_bat, &cw_bat->battery);
> +	if (ret) {
> +		dev_warn(cw_bat->dev,
> +			 "No monitored battery, some properties will be missing\n");
> +	}
> +
> +	cw_bat->battery_workqueue = create_singlethread_workqueue("rk_battery");
> +	INIT_DELAYED_WORK(&cw_bat->battery_delay_work, cw_bat_work);
> +	queue_delayed_work(cw_bat->battery_workqueue,
> +			   &cw_bat->battery_delay_work, msecs_to_jiffies(10));
> +	return 0;
> +}
> +
> +static int __maybe_unused cw_bat_suspend(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct cw_battery *cw_bat = i2c_get_clientdata(client);
> +
> +	cancel_delayed_work_sync(&cw_bat->battery_delay_work);
> +	return 0;
> +}
> +
> +static int __maybe_unused cw_bat_resume(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct cw_battery *cw_bat = i2c_get_clientdata(client);
> +
> +	queue_delayed_work(cw_bat->battery_workqueue,
> +			   &cw_bat->battery_delay_work, 0);
> +	return 0;
> +}
> +
> +SIMPLE_DEV_PM_OPS(cw_bat_pm_ops, cw_bat_suspend, cw_bat_resume);
> +
> +static int cw_bat_remove(struct i2c_client *client)
> +{
> +	struct cw_battery *cw_bat = i2c_get_clientdata(client);
> +
> +	cancel_delayed_work_sync(&cw_bat->battery_delay_work);
> +	power_supply_put_battery_info(cw_bat->rk_bat, &cw_bat->battery);
> +	return 0;
> +}
> +
> +static const struct i2c_device_id cw_bat_id_table[] = {
> +	{ "cw2015", 0 },
> +	{ }
> +};
> +
> +static const struct of_device_id cw2015_of_match[] = {
> +	{ .compatible = "cellwise,cw2015" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, cw2015_of_match);
> +
> +static struct i2c_driver cw_bat_driver = {
> +	.driver = {
> +		.name = "cw2015",
> +		.pm = &cw_bat_pm_ops,
> +	},
> +	.probe_new = cw_bat_probe,
> +	.remove = cw_bat_remove,
> +	.id_table = cw_bat_id_table,
> +};
> +
> +module_i2c_driver(cw_bat_driver);
> +
> +MODULE_AUTHOR("xhc<xhc@rock-chips.com>");
> +MODULE_AUTHOR("Tobias Schramm <t.schramm@manjaro.org>");
> +MODULE_DESCRIPTION("cw2015/cw2013 battery driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.24.1
> 

-- 
With Best Regards,
Andy Shevchenko