[PATCH 0/2] power: supply: RN5T618/RC5T619

[PATCH 0/2] power: supply: RN5T618/RC5T619

[Andreas Kemnade]

This series adds support for the RN5T618/RC5T619 charger and fuel gauge.
Battery and input power status can be read.

Andreas Kemnade (2):
  power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge
  mfd: rn5t618: Add a power supply subdevice

 drivers/mfd/rn5t618.c                |   1 +
 drivers/power/supply/Kconfig         |   8 +
 drivers/power/supply/Makefile        |   1 +
 drivers/power/supply/rn5t618_power.c | 565 +++++++++++++++++++++++++++
 4 files changed, 575 insertions(+)
 create mode 100644 drivers/power/supply/rn5t618_power.c

-- 
2.20.1

[PATCH 1/2] power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge

[Andreas Kemnade]

Both chips have charger and a fuel gauge.

This adds basic support for displaying the state of the battery and the
input power, settings are not modified. There are some defaults set via
OTP.

Charging also starts after plugging USB.

Known issues of the fuel gauge: There are drivers in the wild which disable
the fuel gauge at shutdown. If a kernel is booted without fuel gauge
support, after such a driver has been used, the fuel gauge will stay off
and decalibrate.
If this driver is used after that, it might display wrong values for charge
level.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
 drivers/power/supply/Kconfig         |   8 +
 drivers/power/supply/Makefile        |   1 +
 drivers/power/supply/rn5t618_power.c | 565 +++++++++++++++++++++++++++
 3 files changed, 574 insertions(+)
 create mode 100644 drivers/power/supply/rn5t618_power.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 44d3c8512fb8..28cea178f6f1 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -739,4 +739,12 @@ config CHARGER_WILCO
 	  information can be found in
 	  Documentation/ABI/testing/sysfs-class-power-wilco
 
+config RN5T618_POWER
+	tristate "RN5T618 charger/fuel gauge support"
+	depends on MFD_RN5T618
+	help
+	  Say Y here to have support for RN5T618 PMIC family fuel gauge and charger
+	  This driver can also be built as a module. If so, the module will be
+	  called rn5t618_power.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index b9644663e435..23866b6ccdae 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -95,3 +95,4 @@ obj-$(CONFIG_CHARGER_UCS1002)	+= ucs1002_power.o
 obj-$(CONFIG_CHARGER_BD70528)	+= bd70528-charger.o
 obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o
 obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o
+obj-$(CONFIG_RN5T618_POWER)	+= rn5t618_power.o
diff --git a/drivers/power/supply/rn5t618_power.c b/drivers/power/supply/rn5t618_power.c
new file mode 100644
index 000000000000..f62bcb00f714
--- /dev/null
+++ b/drivers/power/supply/rn5t618_power.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Power supply driver for the RICOH RN5T618 power management chip family
+ *
+ * Copyright (C) 2020 Andreas Kemnade
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mfd/rn5t618.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define CHG_STATE_ADP_INPUT 0x40
+#define CHG_STATE_USB_INPUT 0x80
+#define CHG_STATE_MASK	0x1f
+#define CHG_STATE_CHG_OFF	0
+#define CHG_STATE_CHG_READY_VADP	1
+#define CHG_STATE_CHG_TRICKLE	2
+#define CHG_STATE_CHG_RAPID	3
+#define CHG_STATE_CHG_COMPLETE	4
+#define CHG_STATE_SUSPEND	5
+#define CHG_STATE_VCHG_OVER_VOL	6
+#define CHG_STATE_BAT_ERROR	7
+#define CHG_STATE_NO_BAT	8
+#define CHG_STATE_BAT_OVER_VOL	9
+#define CHG_STATE_BAT_TEMP_ERR	10
+#define CHG_STATE_DIE_ERR	11
+#define CHG_STATE_DIE_SHUTDOWN	12
+#define CHG_STATE_NO_BAT2	13
+#define CHG_STATE_CHG_READY_VUSB	14
+
+#define FG_ENABLE 1
+
+struct rn5t618_power_info {
+	struct rn5t618 *rn5t618;
+	struct platform_device *pdev;
+	struct power_supply *battery;
+	struct power_supply *usb;
+	struct power_supply *adp;
+	int irq;
+};
+
+static enum power_supply_property rn5t618_usb_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+static enum power_supply_property rn5t618_adp_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_ONLINE,
+};
+
+
+static enum power_supply_property rn5t618_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
+	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+};
+
+static int rn5t618_battery_read_doublereg(struct rn5t618_power_info *info,
+					  u8 reg, u16 *result)
+{
+	int ret, i;
+	u8 data[2];
+	u16 old, new;
+
+	old = 0;
+	/* Prevent races when registers are changing. */
+	for (i = 0; i < 3; i++) {
+		ret = regmap_bulk_read(info->rn5t618->regmap,
+				       reg, data, sizeof(data));
+		if (ret)
+			return ret;
+
+		new = data[0] << 8;
+		new |= data[1];
+		if (new == old)
+			break;
+
+		old = new;
+	}
+
+	*result = new;
+
+	return 0;
+}
+
+static int rn5t618_decode_status(unsigned int status)
+{
+	switch (status & CHG_STATE_MASK) {
+	case CHG_STATE_CHG_OFF:
+	case CHG_STATE_SUSPEND:
+	case CHG_STATE_VCHG_OVER_VOL:
+	case CHG_STATE_DIE_SHUTDOWN:
+		return POWER_SUPPLY_STATUS_DISCHARGING;
+
+	case CHG_STATE_CHG_TRICKLE:
+	case CHG_STATE_CHG_RAPID:
+		return POWER_SUPPLY_STATUS_CHARGING;
+
+	case CHG_STATE_CHG_COMPLETE:
+		return POWER_SUPPLY_STATUS_FULL;
+
+	default:
+		return POWER_SUPPLY_STATUS_NOT_CHARGING;
+	}
+}
+
+static int rn5t618_battery_status(struct rn5t618_power_info *info,
+				  union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGSTATE, &v);
+	if (ret)
+		return ret;
+
+	val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	if (v & 0xc0) { /* USB or ADP plugged */
+		val->intval = rn5t618_decode_status(v);
+	} else
+		val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+
+	return ret;
+}
+
+static int rn5t618_battery_present(struct rn5t618_power_info *info,
+				   union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGSTATE, &v);
+	if (ret)
+		return ret;
+
+	v &= CHG_STATE_MASK;
+	if ((v == CHG_STATE_NO_BAT) || (v == CHG_STATE_NO_BAT2))
+		val->intval = 0;
+	else
+		val->intval = 1;
+
+	return ret;
+}
+
+static int rn5t618_battery_voltage_now(struct rn5t618_power_info *info,
+				       union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_VOLTAGE_1, &res);
+	if (ret)
+		return ret;
+
+	val->intval = res * 2 * 2500 / 4095 * 1000;
+
+	return 0;
+}
+
+static int rn5t618_battery_current_now(struct rn5t618_power_info *info,
+				       union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_CC_AVEREG1, &res);
+	if (ret)
+		return ret;
+
+	val->intval = res;
+	/* 2's complement */
+	if (val->intval & (1 << 13))
+		val->intval = val->intval - (1 << 14);
+
+	/* negate current to be positive when discharging */
+	val->intval *= -1000;
+
+	return 0;
+}
+
+static int rn5t618_battery_capacity(struct rn5t618_power_info *info,
+				    union power_supply_propval *val)
+{
+	unsigned int v;
+	int ret;
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_SOC, &v);
+	if (ret)
+		return ret;
+
+	val->intval = v;
+
+	return 0;
+}
+
+static int rn5t618_battery_temp(struct rn5t618_power_info *info,
+				union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_TEMP_1, &res);
+	if (ret)
+		return ret;
+
+	val->intval = res;
+	/* 2's complement */
+	if (val->intval & (1 << 11))
+		val->intval = val->intval - (1 << 12);
+
+	val->intval = val->intval * 10 / 16;
+
+	return 0;
+}
+
+static int rn5t618_battery_tte(struct rn5t618_power_info *info,
+			       union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_TT_EMPTY_H, &res);
+	if (ret)
+		return ret;
+
+	if (res == 65535)
+		return -ENODATA;
+
+	val->intval = res * 60;
+
+	return 0;
+}
+
+static int rn5t618_battery_ttf(struct rn5t618_power_info *info,
+			       union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_TT_FULL_H, &res);
+	if (ret)
+		return ret;
+
+	if (res == 65535)
+		return -ENODATA;
+
+	val->intval = res * 60;
+
+	return 0;
+}
+
+static int rn5t618_battery_charge_full(struct rn5t618_power_info *info,
+				       union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_FA_CAP_H, &res);
+	if (ret)
+		return ret;
+
+	val->intval = res * 1000;
+
+	return 0;
+}
+
+static int rn5t618_battery_charge_now(struct rn5t618_power_info *info,
+				      union power_supply_propval *val)
+{
+	u16 res;
+	int ret;
+
+	ret = rn5t618_battery_read_doublereg(info, RN5T618_RE_CAP_H, &res);
+	if (ret)
+		return ret;
+
+	val->intval = res * 1000;
+
+	return 0;
+}
+
+static int rn5t618_battery_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	int ret = 0;
+	struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = rn5t618_battery_status(info, val);
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		ret = rn5t618_battery_present(info, val);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = rn5t618_battery_voltage_now(info, val);
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = rn5t618_battery_current_now(info, val);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		ret = rn5t618_battery_capacity(info, val);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		ret = rn5t618_battery_temp(info, val);
+		break;
+	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
+		ret = rn5t618_battery_tte(info, val);
+		break;
+	case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
+		ret = rn5t618_battery_ttf(info, val);
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		ret = rn5t618_battery_charge_full(info, val);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		ret = rn5t618_battery_charge_now(info, val);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int rn5t618_adp_get_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+	unsigned int chgstate;
+	bool online;
+	int ret;
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGSTATE, &chgstate);
+	if (ret)
+		return ret;
+
+	online = !!(chgstate & CHG_STATE_ADP_INPUT);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = online;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		if (!online) {
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+			break;
+		}
+		val->intval = rn5t618_decode_status(chgstate);
+		if (val->intval != POWER_SUPPLY_STATUS_CHARGING)
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int rn5t618_usb_get_property(struct power_supply *psy,
+				    enum power_supply_property psp,
+				    union power_supply_propval *val)
+{
+	struct rn5t618_power_info *info = power_supply_get_drvdata(psy);
+	unsigned int chgstate;
+	bool online;
+	int ret;
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_CHGSTATE, &chgstate);
+	if (ret)
+		return ret;
+
+	online = !!(chgstate & CHG_STATE_USB_INPUT);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = online;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		if (!online) {
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+			break;
+		}
+		val->intval = rn5t618_decode_status(chgstate);
+		if (val->intval != POWER_SUPPLY_STATUS_CHARGING)
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct power_supply_desc rn5t618_battery_desc = {
+	.name                   = "rn5t618-battery",
+	.type                   = POWER_SUPPLY_TYPE_BATTERY,
+	.properties             = rn5t618_battery_props,
+	.num_properties         = ARRAY_SIZE(rn5t618_battery_props),
+	.get_property           = rn5t618_battery_get_property,
+};
+
+static const struct power_supply_desc rn5t618_adp_desc = {
+	.name                   = "rn5t618-adp",
+	.type                   = POWER_SUPPLY_TYPE_MAINS,
+	.properties             = rn5t618_usb_props,
+	.num_properties         = ARRAY_SIZE(rn5t618_adp_props),
+	.get_property           = rn5t618_adp_get_property,
+};
+
+static const struct power_supply_desc rn5t618_usb_desc = {
+	.name                   = "rn5t618-usb",
+	.type                   = POWER_SUPPLY_TYPE_USB,
+	.properties             = rn5t618_usb_props,
+	.num_properties         = ARRAY_SIZE(rn5t618_usb_props),
+	.get_property           = rn5t618_usb_get_property,
+};
+
+static irqreturn_t rn5t618_charger_irq(int irq, void *data)
+{
+	struct device *dev = data;
+	struct rn5t618_power_info *info = dev_get_drvdata(dev);
+
+	unsigned int ctrl, stat1, stat2, err;
+
+	regmap_read(info->rn5t618->regmap, RN5T618_CHGERR_IRR, &err);
+	regmap_read(info->rn5t618->regmap, RN5T618_CHGCTRL_IRR, &ctrl);
+	regmap_read(info->rn5t618->regmap, RN5T618_CHGSTAT_IRR1, &stat1);
+	regmap_read(info->rn5t618->regmap, RN5T618_CHGSTAT_IRR2, &stat2);
+
+	regmap_write(info->rn5t618->regmap, RN5T618_CHGERR_IRR, 0);
+	regmap_write(info->rn5t618->regmap, RN5T618_CHGCTRL_IRR, 0);
+	regmap_write(info->rn5t618->regmap, RN5T618_CHGSTAT_IRR1, 0);
+	regmap_write(info->rn5t618->regmap, RN5T618_CHGSTAT_IRR2, 0);
+
+	dev_dbg(dev, "chgerr: %x chgctrl: %x chgstat: %x chgstat2: %x\n",
+		err, ctrl, stat1, stat2);
+
+	power_supply_changed(info->usb);
+	power_supply_changed(info->adp);
+	power_supply_changed(info->battery);
+
+	return IRQ_HANDLED;
+}
+
+static int rn5t618_power_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	unsigned int v;
+	struct power_supply_config psy_cfg = {};
+	struct rn5t618_power_info *info;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->pdev = pdev;
+	info->rn5t618 = dev_get_drvdata(pdev->dev.parent);
+	info->irq = -1;
+
+	platform_set_drvdata(pdev, info);
+
+	ret = regmap_read(info->rn5t618->regmap, RN5T618_CONTROL, &v);
+	if (ret)
+		return ret;
+
+	if (!(v & FG_ENABLE)) {
+		/* E.g. the vendor kernels of various Kobo and Tolino Ebook
+		 * readers disable the fuel gauge on shutdown. If a kernel
+		 * without fuel gauge support is booted after that, the fuel
+		 * gauge will get decalibrated.
+		 */
+		dev_info(&pdev->dev, "Fuel gauge not enabled, enabling now\n");
+		dev_info(&pdev->dev, "Expect unprecise results\n");
+		regmap_update_bits(info->rn5t618->regmap, RN5T618_CONTROL,
+				   FG_ENABLE, FG_ENABLE);
+	}
+
+	psy_cfg.drv_data = info;
+	info->battery = devm_power_supply_register(&pdev->dev,
+						   &rn5t618_battery_desc,
+						   &psy_cfg);
+	if (IS_ERR(info->battery)) {
+		ret = PTR_ERR(info->battery);
+		dev_err(&pdev->dev, "failed to register battery: %d\n", ret);
+		return ret;
+	}
+
+	info->adp = devm_power_supply_register(&pdev->dev,
+					       &rn5t618_adp_desc,
+					       &psy_cfg);
+	if (IS_ERR(info->adp)) {
+		ret = PTR_ERR(info->adp);
+		dev_err(&pdev->dev, "failed to register adp: %d\n", ret);
+		return ret;
+	}
+
+	info->usb = devm_power_supply_register(&pdev->dev,
+					       &rn5t618_usb_desc,
+					       &psy_cfg);
+	if (IS_ERR(info->usb)) {
+		ret = PTR_ERR(info->usb);
+		dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
+		return ret;
+	}
+
+	if (info->rn5t618->irq_data)
+		info->irq = regmap_irq_get_virq(info->rn5t618->irq_data,
+						RN5T618_IRQ_CHG);
+
+	if (info->irq < 0)
+		info->irq = -1;
+	else {
+		ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
+						rn5t618_charger_irq,
+						IRQF_ONESHOT,
+						"rn5t618_power",
+						&pdev->dev);
+
+		if (ret < 0) {
+			dev_err(&pdev->dev, "request IRQ:%d fail\n",
+				info->irq);
+			info->irq = -1;
+		}
+	}
+
+	return 0;
+}
+
+static struct platform_driver rn5t618_power_driver = {
+	.driver = {
+		.name   = "rn5t618-power",
+	},
+	.probe = rn5t618_power_probe,
+};
+
+module_platform_driver(rn5t618_power_driver);
+MODULE_ALIAS("platform:rn5t618-power");
+MODULE_DESCRIPTION("Power supply driver for RICOH RN5T618");
+MODULE_LICENSE("GPL");
-- 
2.20.1

Re: [PATCH 1/2] power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge

[Sebastian Reichel]

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Hi,

Driver looks mostly good.

On Sat, Aug 15, 2020 at 06:56:09PM +0200, Andreas Kemnade wrote:
> [...]
> +static int rn5t618_battery_current_now(struct rn5t618_power_info *info,
> +				       union power_supply_propval *val)
> +{
> +	u16 res;
> +	int ret;
> +
> +	ret = rn5t618_battery_read_doublereg(info, RN5T618_CC_AVEREG1, &res);
> +	if (ret)
> +		return ret;
> +
> +	val->intval = res;
> +	/* 2's complement */
> +	if (val->intval & (1 << 13))
> +		val->intval = val->intval - (1 << 14);
> +
> +	/* negate current to be positive when discharging */
> +	val->intval *= -1000;

mh, the sign is not documented (which should be fixed). At least
sbs-battery does it the other way around (negative current when
discharging, positive otherwise). Some drivers do not support
signed current and always report positive values (e.g. ACPI driver).

What did you use as reference for swapping the sign?

> +	return 0;
> +}
> [...]
> +static const struct power_supply_desc rn5t618_adp_desc = {
> +	.name                   = "rn5t618-adp",
> +	.type                   = POWER_SUPPLY_TYPE_MAINS,
> +	.properties             = rn5t618_usb_props,

wrong property array, works by accident since usb and adp property
lists are the same.

> +	.num_properties         = ARRAY_SIZE(rn5t618_adp_props),
> +	.get_property           = rn5t618_adp_get_property,
> +};
> [...]

-- Sebastian

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Re: [PATCH 1/2] power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge

[Andreas Kemnade]

On Wed, 26 Aug 2020 19:48:17 +0200
Sebastian Reichel <sebastian.reichel@collabora.com> wrote:

> Hi,
> 
> Driver looks mostly good.
> 
> On Sat, Aug 15, 2020 at 06:56:09PM +0200, Andreas Kemnade wrote:
> > [...]
> > +static int rn5t618_battery_current_now(struct rn5t618_power_info *info,
> > +				       union power_supply_propval *val)
> > +{
> > +	u16 res;
> > +	int ret;
> > +
> > +	ret = rn5t618_battery_read_doublereg(info, RN5T618_CC_AVEREG1, &res);
> > +	if (ret)
> > +		return ret;
> > +
> > +	val->intval = res;
> > +	/* 2's complement */
> > +	if (val->intval & (1 << 13))
> > +		val->intval = val->intval - (1 << 14);
> > +
> > +	/* negate current to be positive when discharging */
> > +	val->intval *= -1000;  
> 
> mh, the sign is not documented (which should be fixed). At least
> sbs-battery does it the other way around (negative current when
> discharging, positive otherwise). Some drivers do not support
> signed current and always report positive values (e.g. ACPI driver).
> 
> What did you use as reference for swapping the sign?
> 
Well, I have searched for documentation, found nothing and used the
bq27xxx driver as reference  which I am used to from the GTA04/GTA02,
so things behave equal. That are the devices where a was most
intensively looking at those values.
I thought that there would be some unwritten rule about that.

Regards,
Andreas

Re: [PATCH 1/2] power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge

[Sebastian Reichel]

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Hi,

On Wed, Aug 26, 2020 at 08:28:34PM +0200, Andreas Kemnade wrote:
> On Wed, 26 Aug 2020 19:48:17 +0200
> Sebastian Reichel <sebastian.reichel@collabora.com> wrote:
> > On Sat, Aug 15, 2020 at 06:56:09PM +0200, Andreas Kemnade wrote:
> > > [...]
> > > +static int rn5t618_battery_current_now(struct rn5t618_power_info *info,
> > > +				       union power_supply_propval *val)
> > > +{
> > > +	u16 res;
> > > +	int ret;
> > > +
> > > +	ret = rn5t618_battery_read_doublereg(info, RN5T618_CC_AVEREG1, &res);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	val->intval = res;
> > > +	/* 2's complement */
> > > +	if (val->intval & (1 << 13))
> > > +		val->intval = val->intval - (1 << 14);

Btw. I think sign_extend32() can be used here?

> > > +	/* negate current to be positive when discharging */
> > > +	val->intval *= -1000;  
> > 
> > mh, the sign is not documented (which should be fixed). At least
> > sbs-battery does it the other way around (negative current when
> > discharging, positive otherwise). Some drivers do not support
> > signed current and always report positive values (e.g. ACPI driver).
> > 
> > What did you use as reference for swapping the sign?
> > 
> Well, I have searched for documentation, found nothing and used the
> bq27xxx driver as reference  which I am used to from the GTA04/GTA02,
> so things behave equal. That are the devices where a was most
> intensively looking at those values.
> I thought that there would be some unwritten rule about that.

The mess is mostly due to lacking reviewing from my side
(and possibly my predecessors). I just went through a dozen of
drivers and it looks like most either do not support signed current
(and use negative values as error code :() or use negative current
for discharge. I could not find any other driver using negative
numbers for charging. I think it's best to negative = discharge as
official correct value and will send an update patch for the
documentation later.

-- Sebastian

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Re: [PATCH 1/2] power: supply: Add support for RN5T618/RC5T619 charger and fuel gauge

[Andreas Kemnade]

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Hi,

On Wed, 26 Aug 2020 23:59:50 +0200
Sebastian Reichel <sebastian.reichel@collabora.com> wrote:

> Hi,
> 
> On Wed, Aug 26, 2020 at 08:28:34PM +0200, Andreas Kemnade wrote:
> > On Wed, 26 Aug 2020 19:48:17 +0200
> > Sebastian Reichel <sebastian.reichel@collabora.com> wrote:  
> > > On Sat, Aug 15, 2020 at 06:56:09PM +0200, Andreas Kemnade wrote:  
> > > > [...]
> > > > +static int rn5t618_battery_current_now(struct rn5t618_power_info *info,
> > > > +				       union power_supply_propval *val)
> > > > +{
> > > > +	u16 res;
> > > > +	int ret;
> > > > +
> > > > +	ret = rn5t618_battery_read_doublereg(info, RN5T618_CC_AVEREG1, &res);
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > > +	val->intval = res;
> > > > +	/* 2's complement */
> > > > +	if (val->intval & (1 << 13))
> > > > +		val->intval = val->intval - (1 << 14);  
> 
> Btw. I think sign_extend32() can be used here?
> 
> > > > +	/* negate current to be positive when discharging */
> > > > +	val->intval *= -1000;    
> > > 
> > > mh, the sign is not documented (which should be fixed). At least
> > > sbs-battery does it the other way around (negative current when
> > > discharging, positive otherwise). Some drivers do not support
> > > signed current and always report positive values (e.g. ACPI driver).
> > > 
> > > What did you use as reference for swapping the sign?
> > >   
> > Well, I have searched for documentation, found nothing and used the
> > bq27xxx driver as reference  which I am used to from the GTA04/GTA02,
> > so things behave equal. That are the devices where a was most
> > intensively looking at those values.
> > I thought that there would be some unwritten rule about that.  
> 
> The mess is mostly due to lacking reviewing from my side
> (and possibly my predecessors). I just went through a dozen of
> drivers and it looks like most either do not support signed current
> (and use negative values as error code :() or use negative current
> for discharge. I could not find any other driver using negative
> numbers for charging. I think it's best to negative = discharge as
> official correct value and will send an update patch for the
> documentation later.
> 
ok, I will remove that sign-change and keep/update the comment
so that you know that the driver does it the official way
and send a v2 with the other things you mentioned.

Regards,
Andreas

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[PATCH 2/2] mfd: rn5t618: Add a power supply subdevice

[Andreas Kemnade]

The RN5T618 and RC5T619 both have a charger and a fuel gauge, so add
a subdevice for it. According to drivers in the wild, things
should be at least similar, but since it is not tested, add it
only to the RC5T619.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
 drivers/mfd/rn5t618.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
index e25407ed3ad4..dc452df1f1bf 100644
--- a/drivers/mfd/rn5t618.c
+++ b/drivers/mfd/rn5t618.c
@@ -25,6 +25,7 @@ static const struct mfd_cell rn5t618_cells[] = {
 
 static const struct mfd_cell rc5t619_cells[] = {
 	{ .name = "rn5t618-adc" },
+	{ .name = "rn5t618-power" },
 	{ .name = "rn5t618-regulator" },
 	{ .name = "rc5t619-rtc" },
 	{ .name = "rn5t618-wdt" },
-- 
2.20.1

Re: [PATCH 2/2] mfd: rn5t618: Add a power supply subdevice

[Lee Jones]

On Sat, 15 Aug 2020, Andreas Kemnade wrote:

> The RN5T618 and RC5T619 both have a charger and a fuel gauge, so add
> a subdevice for it. According to drivers in the wild, things
> should be at least similar, but since it is not tested, add it
> only to the RC5T619.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---
>  drivers/mfd/rn5t618.c | 1 +
>  1 file changed, 1 insertion(+)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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