From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0AF1932939A; Thu, 29 Jan 2026 01:59:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769652006; cv=pass; b=HYrNXaREox9Ef1nHE1V2wDSjWGBW5KVR/geHdM8Kn3uHuPCCyG9+k8ReMzl+38EbRwy6IZgPwhnHUMgl4rbkx7sSoSotm9djex2lNEYXPo557mEia7Irw21y/rNma6Ne192ingt0yzzH44LYPiacnFDJIi5U86iiJnGurZe0sW0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769652006; c=relaxed/simple; bh=dNEMvvA7Po74dPo+VkXMBYfoEJKz7EwcUzE1RrpHAmQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qxEUYNUZd7z+LjvuGpyfYhAMxhJevifpXIGjatOWx+ITGRLA6xJrC0rzAzlUoQ3YPxoJAdOZlVTdtwwiOSDuwyQmCtgg2oAvWQ+TjjQnhMVnN8jL0OdLumzeU+n8/GbTlP0gzlrsrSUuza13P3Mlvi85nITR1aAA+Wps/2Z6qNA= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=sebastian.reichel@collabora.com header.b=ghruuMaT; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=sebastian.reichel@collabora.com header.b="ghruuMaT" ARC-Seal: i=1; a=rsa-sha256; t=1769651984; cv=none; d=zohomail.com; s=zohoarc; b=gfhdkELQ+r9VRoig5g3ceCRoO1KM5yCJmcdLfFEmlesal5zAlHZzEuahO0j9+2GrMmgb7SajG/OKuFFtYPb35h09xsS+Lbih0iesuTxP9HeNkUUgQHYOAHixk3T7pyKdjR6x5RK99QGKRoTtdgnOr40SaoaeM0Sbo0nltWTklb8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1769651984; h=Content-Type:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=T3aKX84kGxI1xxaoYSc/3afEikkxjamWfp3cnXS6LCk=; b=CcM7ghj+dKBRdqKOF2CNoG/agmkPmj+s7IVPUzOU9Xm6u0NK1RrLBKHr5mMmGfAuaOc0tlhWl7GFZHqNl2IJopqTjTtxxmVCCxLbEYUQcfMSp4sjrmcBv72x7niaRAwuPgerZ3bjzoa/rV8uORRyY5jAqbBWRyOTbxFCa8+ma2o= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=sebastian.reichel@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1769651984; s=zohomail; d=collabora.com; i=sebastian.reichel@collabora.com; h=Date:Date:From:From:To:To:Cc:Cc:Subject:Subject:Message-ID:References:MIME-Version:Content-Type:In-Reply-To:Message-Id:Reply-To; bh=T3aKX84kGxI1xxaoYSc/3afEikkxjamWfp3cnXS6LCk=; b=ghruuMaTCTutArmV7+GMqjzzbh85cW0vDGhdzK7XuFEUNJ+9MEO+V6iA9DObp7rB 8VKaDuIbz26pI/WimZTSHuKDlw050W1CiKCbLqJiX2jMiJZwfsy2/Sz2qtQogv/8+q6 BCo0xgtObeWNMfkxuqgnv9txqDWCzAE5yMW20ChE= Received: by mx.zohomail.com with SMTPS id 176965198298465.12795747038842; Wed, 28 Jan 2026 17:59:42 -0800 (PST) Received: by venus (Postfix, from userid 1000) id 7941818060F; Thu, 29 Jan 2026 02:59:39 +0100 (CET) Date: Thu, 29 Jan 2026 02:59:39 +0100 From: Sebastian Reichel To: Kaustabh Chakraborty Cc: Yassine Oudjana , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] power: supply: add support for S2MU005 battery fuel gauge device Message-ID: References: <20260126-s2mu005-fuelgauge-v1-0-68a146ed0819@disroot.org> <20260126-s2mu005-fuelgauge-v1-2-68a146ed0819@disroot.org> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="rsep7zu3ekqtwnyl" Content-Disposition: inline In-Reply-To: <20260126-s2mu005-fuelgauge-v1-2-68a146ed0819@disroot.org> X-Zoho-Virus-Status: 1 X-Zoho-AV-Stamp: zmail-av-0.2.1.1.4.3/269.648.70 X-ZohoMailClient: External --rsep7zu3ekqtwnyl Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH 2/2] power: supply: add support for S2MU005 battery fuel gauge device MIME-Version: 1.0 Hi, On Mon, Jan 26, 2026 at 09:09:49PM +0530, Kaustabh Chakraborty wrote: > From: Yassine Oudjana >=20 > Samsung's S2MU005 PMIC, which contains battery charger functionality > also includes a battery fuel gauge device, which is separate from the > PMIC itself, and typically connected to an I2C bus. Add a generic driver > to support said device. >=20 > Signed-off-by: Yassine Oudjana > Co-developed-by: Kaustabh Chakraborty > Signed-off-by: Kaustabh Chakraborty > --- > drivers/power/supply/Kconfig | 9 ++ > drivers/power/supply/Makefile | 1 + > drivers/power/supply/s2mu005-battery.c | 234 +++++++++++++++++++++++++++= ++++++ > 3 files changed, 244 insertions(+) >=20 > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > index 92f9f7aae92f2..a5777309b1f62 100644 > --- a/drivers/power/supply/Kconfig > +++ b/drivers/power/supply/Kconfig > @@ -229,6 +229,15 @@ config BATTERY_SAMSUNG_SDI > Say Y to enable support for Samsung SDI battery data. > These batteries are used in Samsung mobile phones. > =20 > +config BATTERY_S2MU005 > + tristate "Samsung S2MU005 PMIC fuel gauge driver" > + help > + Say Y to enable support for the Samsung S2MU005 PMIC integrated > + fuel gauge, which works indepenently of the PMIC battery charger > + counterpart, and reports battery metrics. > + > + This driver, if built as a module, will be called s2mu005-fuel-gauge. > + > config BATTERY_COLLIE > tristate "Sharp SL-5500 (collie) battery" > depends on SA1100_COLLIE && MCP_UCB1200 > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > index 4b79d5abc49a7..cd061887c1727 100644 > --- a/drivers/power/supply/Makefile > +++ b/drivers/power/supply/Makefile > @@ -40,6 +40,7 @@ obj-$(CONFIG_BATTERY_PMU) +=3D pmu_battery.o > obj-$(CONFIG_BATTERY_QCOM_BATTMGR) +=3D qcom_battmgr.o > obj-$(CONFIG_BATTERY_OLPC) +=3D olpc_battery.o > obj-$(CONFIG_BATTERY_SAMSUNG_SDI) +=3D samsung-sdi-battery.o > +obj-$(CONFIG_BATTERY_S2MU005) +=3D s2mu005-battery.o > obj-$(CONFIG_BATTERY_COLLIE) +=3D collie_battery.o > obj-$(CONFIG_BATTERY_INGENIC) +=3D ingenic-battery.o > obj-$(CONFIG_BATTERY_INTEL_DC_TI) +=3D intel_dc_ti_battery.o > diff --git a/drivers/power/supply/s2mu005-battery.c b/drivers/power/suppl= y/s2mu005-battery.c > new file mode 100644 > index 0000000000000..914308e82683b > --- /dev/null > +++ b/drivers/power/supply/s2mu005-battery.c > @@ -0,0 +1,234 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Battery Fuel Gauge Driver for Samsung S2MU005 PMIC. > + * > + * Copyright (C) 2015 Samsung Electronics > + * Copyright (C) 2023 Yassine Oudjana > + * Copyright (C) 2025 Kaustabh Chakraborty > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define S2MU005_FG_REG_STATUS 0x00 > +#define S2MU005_FG_REG_IRQ 0x02 > +#define S2MU005_FG_REG_RVBAT 0x04 > +#define S2MU005_FG_REG_RCUR_CC 0x06 > +#define S2MU005_FG_REG_RSOC 0x08 > +#define S2MU005_FG_REG_MONOUT 0x0a > +#define S2MU005_FG_REG_MONOUT_SEL 0x0c > +#define S2MU005_FG_REG_RBATCAP 0x0e > +#define S2MU005_FG_REG_RZADJ 0x12 > +#define S2MU005_FG_REG_RBATZ0 0x16 > +#define S2MU005_FG_REG_RBATZ1 0x18 > +#define S2MU005_FG_REG_IRQ_LVL 0x1a > +#define S2MU005_FG_REG_START 0x1e > + > +struct s2mu005_fg { > + struct device *dev; > + struct regmap *regmap; > + struct power_supply *psy; > +}; > + > +static const struct regmap_config s2mu005_fg_regmap_config =3D { > + .reg_bits =3D 8, > + .val_bits =3D 8, > +}; Looks like all register addresses are 2 byte aligned and you are always using regmap_raw_read to get 16bit values. So just use =2Eval_bits =3D 16 here? > +static irqreturn_t s2mu005_handle_irq(int irq, void *data) > +{ > + struct s2mu005_fg *priv =3D data; > + > + msleep(100); > + power_supply_changed(priv->psy); > + > + return IRQ_HANDLED; > +} > + > +static int s2mu005_fg_get_voltage_now(struct s2mu005_fg *priv, int *valu= e) > +{ > + struct regmap *regmap =3D priv->regmap; > + u16 reg; > + int ret; > + > + ret =3D regmap_raw_read(regmap, S2MU005_FG_REG_RVBAT, ®, sizeof(reg)= ); > + if (ret < 0) { > + dev_err(priv->dev, "failed to read voltage register (%d)\n", ret); > + return ret; > + } > + > + *value =3D ((unsigned long)reg * 1000000) >> 13; /* uV */ > + > + return 0; > +} > + > +static int s2mu005_fg_get_current_now(struct s2mu005_fg *priv, int *valu= e) > +{ > + struct regmap *regmap =3D priv->regmap; > + s16 reg; > + int ret; > + > + ret =3D regmap_raw_read(regmap, S2MU005_FG_REG_RCUR_CC, ®, sizeof(re= g)); > + if (ret < 0) { > + dev_err(priv->dev, "failed to read current register (%d)\n", ret); > + return ret; > + } > + > + *value =3D -((long)reg * 1000000) >> 12; /* uA */ > + > + return 0; > +} > + > +static int s2mu005_fg_get_capacity(struct s2mu005_fg *priv, int *value) > +{ > + struct regmap *regmap =3D priv->regmap; > + s16 reg; > + int ret; > + > + ret =3D regmap_raw_read(regmap, S2MU005_FG_REG_RSOC, ®, sizeof(reg)); > + if (ret < 0) { > + dev_err(priv->dev, "failed to read capacity register (%d)\n", ret); > + return ret; > + } > + > + *value =3D (reg * 100) >> 14; /* percentage */ > + > + return 0; > +} > + > +static int s2mu005_fg_get_status(struct s2mu005_fg *priv, int *value) > +{ > + int current_now; > + int capacity; > + int ret; > + > + ret =3D s2mu005_fg_get_current_now(priv, ¤t_now); > + if (ret) > + return ret; > + > + if (current_now <=3D 0) { > + *value =3D POWER_SUPPLY_STATUS_DISCHARGING; > + return 0; > + } > + > + ret =3D s2mu005_fg_get_capacity(priv, &capacity); > + if (ret) > + return ret; > + > + if (capacity < 90) > + *value =3D POWER_SUPPLY_STATUS_CHARGING; > + else > + *value =3D POWER_SUPPLY_STATUS_FULL; Usually there is some kind of hysteresis that stops charging when the battery is full and then restarts charging once the battery drops under a certain capacity. As this code first checks the current to determine if the battery is discharging and only then checks if the battery is full - does your code toggle between FULL and DISCHARGING? > + return 0; > +} > + > +static const enum power_supply_property s2mu005_fg_properties[] =3D { > + POWER_SUPPLY_PROP_VOLTAGE_NOW, > + POWER_SUPPLY_PROP_CURRENT_NOW, > + POWER_SUPPLY_PROP_CAPACITY, > + POWER_SUPPLY_PROP_STATUS, > +}; > + > +static int s2mu005_fg_get_property(struct power_supply *psy, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + struct s2mu005_fg *priv =3D power_supply_get_drvdata(psy); > + int ret =3D 0; > + > + switch (psp) { > + case POWER_SUPPLY_PROP_VOLTAGE_NOW: > + ret =3D s2mu005_fg_get_voltage_now(priv, &val->intval); > + break; > + case POWER_SUPPLY_PROP_CURRENT_NOW: > + ret =3D s2mu005_fg_get_current_now(priv, &val->intval); > + break; > + case POWER_SUPPLY_PROP_CAPACITY: > + ret =3D s2mu005_fg_get_capacity(priv, &val->intval); > + break; > + case POWER_SUPPLY_PROP_STATUS: > + ret =3D s2mu005_fg_get_status(priv, &val->intval); > + break; > + default: > + return -EINVAL; > + } > + > + return ret; > +} > + > +static const struct power_supply_desc s2mu005_fg_desc =3D { > + .name =3D "s2mu005-fuel-gauge", > + .type =3D POWER_SUPPLY_TYPE_BATTERY, > + .properties =3D s2mu005_fg_properties, > + .num_properties =3D ARRAY_SIZE(s2mu005_fg_properties), > + .get_property =3D s2mu005_fg_get_property, > +}; > + > +static int s2mu005_fg_i2c_probe(struct i2c_client *client) > +{ > + struct device *dev =3D &client->dev; > + struct s2mu005_fg *priv; > + struct power_supply_config psy_cfg =3D {}; > + const struct power_supply_desc *psy_desc; > + int flags; > + int ret; > + > + priv =3D devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return dev_err_probe(dev, -ENOMEM, > + "failed to allocate driver private\n"); Do not print error messages for -ENOMEM. > + > + dev_set_drvdata(dev, priv); > + priv->dev =3D dev; > + > + priv->regmap =3D devm_regmap_init_i2c(client, &s2mu005_fg_regmap_config= ); > + if (IS_ERR(priv->regmap)) > + return dev_err_probe(dev, PTR_ERR(priv->regmap), > + "failed to initialize regmap\n"); > + > + psy_desc =3D device_get_match_data(dev); > + > + psy_cfg.drv_data =3D priv; > + priv->psy =3D devm_power_supply_register(priv->dev, psy_desc, &psy_cfg); > + if (IS_ERR(priv->psy)) > + return dev_err_probe(dev, PTR_ERR(priv->psy), > + "failed to register power supply subsystem\n"); > + > + flags =3D irq_get_trigger_type(client->irq); This is not needed. By not specifying the trigger type the irq core code will do this internally. > + ret =3D devm_request_threaded_irq(priv->dev, client->irq, NULL, > + s2mu005_handle_irq, IRQF_ONESHOT | flags, > + psy_desc->name, priv); > + if (ret) > + dev_err_probe(dev, ret, "failed to request IRQ\n"); > + > + return 0; > +} > + > +static const struct of_device_id s2mu005_fg_of_match_table[] =3D { > + { > + .compatible =3D "samsung,s2mu005-fuel-gauge", > + .data =3D &s2mu005_fg_desc, > + }, { }, Please put the terminator into its own line and remove the final , > +}; > +MODULE_DEVICE_TABLE(of, s2mu005_fg_of_match_table); > + > +static struct i2c_driver s2mu005_fg_i2c_driver =3D { > + .probe =3D s2mu005_fg_i2c_probe, > + .driver =3D { > + .name =3D "s2mu005-fuel-gauge", > + .of_match_table =3D of_match_ptr(s2mu005_fg_of_match_table), Remove of_match_ptr(). > + }, > +}; > +module_i2c_driver(s2mu005_fg_i2c_driver); > + > +MODULE_DESCRIPTION("Samsung S2MU005 PMIC Battery Fuel Gauge Driver"); > +MODULE_AUTHOR("Yassine Oudjana "); > +MODULE_AUTHOR("Kaustabh Chakraborty "); > +MODULE_LICENSE("GPL"); Greetings, -- Sebastian --rsep7zu3ekqtwnyl Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAml6vwgACgkQ2O7X88g7 +pouihAAktRDxmuZDyU1KNjt+7R10pBlcDIt4VaeEpTIBgCp9WlUTREwAQUim1bd UnFkjQOzXdQO6HqrEsu0AuUjyPfzXG8xmL63G1RMMZsd9fD2V3QaSNBSRFsUIW8Y dtE1B2PmNz1y3dS7Enbao7T5LaFQ6/dgnkchDlTK6nQv6ThcPM353eQXkmYeG7Ji w80MGlMp3gUwMUwK8Gw/+kacDMgl7d0UicRCFmZsmbjJRkwjvVTmOYq91xK0O+tL 6oE8vrxQJL6lk3kvy84DdNa6ZgYpJM326VMOgxlJhRhj2Lv4euQ5rUiKGRqTKV3C 5jfuq/ZvBIjSlgKjHKGOvTaIyTMEhWf/WSL9HpH9pDEsDBhtjBdtv1WDTWfC4ROa cZ5NWZdDwVDxefEq/UTDcox3XJxqqu0Kl8vUkzgIxhuMgsqDgXbymjxef6j5hDpp ly7O3RZegax+wtp6GpZ3Zl+cqc9D87gXtSYQEt3fDjnRM5DYzhqXlNPWSAVA8wvh 3F6C6yHQu2M+CmwU3mwhhFrWTifS8Jw7MRNKvEn/QMxseL8IgUI+iXT5fgnYYeKT kvVZRHJq2+PyH+/Mbx98BPNNavpujDF8l7svQSkZXt9SLVBrhLLtF0YERHcHwByI qG4Hg3+naim9hO0rVYevAsRcWlMJ0y+RipOAW7FCh7cQQGsxHlA= =BtkD -----END PGP SIGNATURE----- --rsep7zu3ekqtwnyl--