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From:   Tobias Schramm <t.schramm@manjaro.org>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Sebastian Reichel <sre@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>
Cc:     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,
        Tobias Schramm <t.schramm@manjaro.org>
Subject: [PATCH v3 3/3] power: supply: add CellWise cw2015 fuel gauge driver
Date:   Wed, 11 Mar 2020 10:30:43 +0100
Message-Id: <20200311093043.3636807-4-t.schramm@manjaro.org>
In-Reply-To: <20200311093043.3636807-1-t.schramm@manjaro.org>
References: <20200311093043.3636807-1-t.schramm@manjaro.org>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.

Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
---
 MAINTAINERS                           |   6 +
 drivers/power/supply/Kconfig          |   8 +
 drivers/power/supply/Makefile         |   1 +
 drivers/power/supply/cw2015_battery.c | 785 ++++++++++++++++++++++++++
 4 files changed, 800 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..ac905ce60e47 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -116,6 +116,14 @@ 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)
+
 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..14b1bd687643
--- /dev/null
+++ b/drivers/power/supply/cw2015_battery.c
@@ -0,0 +1,785 @@
+// 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/init.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/timekeeping.h>
+#include <linux/workqueue.h>
+
+#define CW2015_SIZE_BATINFO		64
+
+#define CW2015_READ_TRIES		30
+#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, i;
+	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,
+			"Device is in sleep mode, can't update battery info");
+		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 */
+	for (i = 0; i < CW2015_READ_TRIES; i++) {
+		ret = regmap_read(cw_bat->regmap, CW2015_REG_SOC, &reg_val);
+		if (ret)
+			return ret;
+		/* SoC must not be more than 100% */
+		else if (reg_val <= 100)
+			break;
+
+		msleep(100);
+	}
+
+	if (i >= CW2015_READ_TRIES) {
+		reg_val = CW2015_MODE_SLEEP;
+		regmap_write(cw_bat->regmap, CW2015_REG_MODE, reg_val);
+		dev_err(cw_bat->dev,
+			"Gauge did not become ready after profile upload");
+		return -ETIMEDOUT;
+	}
+
+
+	dev_dbg(cw_bat->dev, "Battery profile updated");
+	return 0;
+}
+
+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");
+		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");
+		if (cw_bat->bat_profile) {
+			ret = cw_update_profile(cw_bat);
+			if (ret) {
+				dev_err(cw_bat->dev,
+					 "Failed to upload battery info\n");
+				return ret;
+			}
+		} else {
+			dev_warn(cw_bat->dev,
+				"Have no battery profile for uploading, continuing without profile");
+		}
+	} 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");
+			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");
+	}
+
+	dev_dbg(cw_bat->dev, "Battery profile configured");
+	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%%", 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");
+			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", 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",
+				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",
+			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",
+			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",
+			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;
+	int i = 0;
+
+	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", ret);
+	} else {
+		if ((reg_val & CW2015_MODE_SLEEP_MASK) == CW2015_MODE_SLEEP) {
+			for (i = 0; i < CW2015_RESET_TRIES; i++) {
+				if (cw_power_on_reset(cw_bat) == 0)
+					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", cw_bat->charger_attached);
+	dev_dbg(cw_bat->dev, "status = %d", cw_bat->status);
+	dev_dbg(cw_bat->dev, "soc = %d%%", cw_bat->soc);
+	dev_dbg(cw_bat->dev, "voltage = %dmV", 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)
+{
+	int ret = 0;
+	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 ret;
+}
+
+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;
+	u32 value;
+	int ret;
+
+	length = device_property_read_u8_array(dev, "cellwise,battery-profile",
+						NULL, 0);
+	if (length) {
+		if (length != CW2015_SIZE_BATINFO) {
+			dev_err(cw_bat->dev, "battery-profile must be %d bytes",
+				CW2015_SIZE_BATINFO);
+			return -EINVAL;
+		}
+
+		cw_bat->bat_profile =
+			devm_kzalloc(dev, CW2015_SIZE_BATINFO, GFP_KERNEL);
+		if (!cw_bat->bat_profile) {
+			dev_err(cw_bat->dev,
+				"Failed to allocate memory for battery config info");
+			return -ENOMEM;
+		}
+
+		ret = device_property_read_u8_array(dev,
+						"cellwise,battery-profile",
+						cw_bat->bat_profile,
+						CW2015_SIZE_BATINFO);
+		if (ret)
+			return ret;
+	} else {
+		dev_warn(cw_bat->dev,
+			"No battery-profile found, rolling with current flash contents");
+	}
+
+	cw_bat->poll_interval_ms = CW2015_DEFAULT_POLL_INTERVAL_MS;
+	ret = device_property_read_u32_array(dev,
+						"cellwise,monitor-interval-ms",
+						&value, 1);
+	if (ret >= 0) {
+		dev_dbg(cw_bat->dev, "Overriding default monitor-interval with %u ms",
+			value);
+		cw_bat->poll_interval_ms = value;
+	}
+
+	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,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct cw_battery *cw_bat;
+	struct power_supply_config psy_cfg = { };
+
+	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");
+		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",
+			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", 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");
+		return -1;
+	}
+
+	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");
+	}
+
+	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 = 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