From: Michał Mirosław <mirq-linux@rere.qmqm.pl>

Driver implements one battery cell per EC controller and supports reading
of battery status for ASUS Transformer's pad and mobile dock.

Co-developed-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/power/supply/Kconfig                  |  11 +
 drivers/power/supply/Makefile                 |   1 +
 .../supply/asus-transformer-ec-battery.c      | 272 ++++++++++++++++++
 3 files changed, 284 insertions(+)
 create mode 100644 drivers/power/supply/asus-transformer-ec-battery.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 81fadb0695a9..3c46b412632d 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -122,6 +122,17 @@ config BATTERY_CHAGALL
 	  This driver can also be built as a module. If so, the module will be
 	  called chagall-battery.
 
+config BATTERY_ASUS_TRANSFORMER_EC
+	tristate "Asus Transformer's battery driver"
+	depends on MFD_ASUS_TRANSFORMER_EC
+	help
+	  Say Y here to enable support APM status emulation using
+	  battery class devices.
+
+	  This sub-driver supports battery cells found in Asus Transformer
+	  tablets and mobile docks and controlled by special embedded
+	  controller.
+
 config BATTERY_CPCAP
 	tristate "Motorola CPCAP PMIC battery driver"
 	depends on MFD_CPCAP && IIO
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 41c400bbf022..aa5e6b05b018 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_TEST_POWER)	+= test_power.o
 obj-$(CONFIG_BATTERY_88PM860X)	+= 88pm860x_battery.o
 obj-$(CONFIG_CHARGER_ADP5061)	+= adp5061.o
 obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
+obj-$(CONFIG_BATTERY_ASUS_TRANSFORMER_EC)	+= asus-transformer-ec-battery.o
 obj-$(CONFIG_BATTERY_AXP20X)	+= axp20x_battery.o
 obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
 obj-$(CONFIG_BATTERY_CHAGALL)	+= chagall-battery.o
diff --git a/drivers/power/supply/asus-transformer-ec-battery.c b/drivers/power/supply/asus-transformer-ec-battery.c
new file mode 100644
index 000000000000..aefcd3fed6fe
--- /dev/null
+++ b/drivers/power/supply/asus-transformer-ec-battery.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/array_size.h>
+#include <linux/devm-helpers.h>
+#include <linux/err.h>
+#include <linux/mfd/asus-transformer-ec.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/property.h>
+#include <linux/unaligned.h>
+
+#define ASUSEC_BATTERY_DATA_FRESH_MSEC		5000
+
+#define ASUSEC_BATTERY_DISCHARGING		0x40
+#define ASUSEC_BATTERY_FULL_CHARGED		0x20
+#define ASUSEC_BATTERY_NOT_CHARGING		0x10
+
+#define TEMP_CELSIUS_OFFSET			2731
+
+struct asus_ec_battery_data {
+	const struct asusec_info *ec;
+	struct power_supply *battery;
+	struct power_supply_desc psy_desc;
+	struct delayed_work poll_work;
+	struct mutex battery_lock; /* for data refresh */
+	unsigned long batt_data_ts;
+	int last_state;
+	u8 batt_data[DOCKRAM_ENTRY_BUFSIZE];
+};
+
+static int asus_ec_battery_refresh(struct asus_ec_battery_data *priv)
+{
+	int ret = 0;
+
+	guard(mutex)(&priv->battery_lock);
+
+	if (time_before(jiffies, priv->batt_data_ts))
+		return ret;
+
+	ret = asus_dockram_read(priv->ec->dockram, ASUSEC_DOCKRAM_BATT_CTL,
+				priv->batt_data);
+	if (ret < 0)
+		return ret;
+
+	priv->batt_data_ts = jiffies +
+		msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC);
+
+	return ret;
+}
+
+static enum power_supply_property asus_ec_battery_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_VOLTAGE_MAX,
+	POWER_SUPPLY_PROP_CURRENT_MAX,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
+	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
+	POWER_SUPPLY_PROP_PRESENT,
+};
+
+static const unsigned int asus_ec_battery_prop_offs[] = {
+	[POWER_SUPPLY_PROP_STATUS] = 1,
+	[POWER_SUPPLY_PROP_VOLTAGE_MAX] = 3,
+	[POWER_SUPPLY_PROP_CURRENT_MAX] = 5,
+	[POWER_SUPPLY_PROP_TEMP] = 7,
+	[POWER_SUPPLY_PROP_VOLTAGE_NOW] = 9,
+	[POWER_SUPPLY_PROP_CURRENT_NOW] = 11,
+	[POWER_SUPPLY_PROP_CAPACITY] = 13,
+	[POWER_SUPPLY_PROP_CHARGE_NOW] = 15,
+	[POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW] = 17,
+	[POWER_SUPPLY_PROP_TIME_TO_FULL_NOW] = 19,
+};
+
+static int asus_ec_battery_get_value(struct asus_ec_battery_data *priv,
+				     enum power_supply_property psp)
+{
+	int ret, offs;
+
+	if (psp >= ARRAY_SIZE(asus_ec_battery_prop_offs))
+		return -EINVAL;
+
+	offs = asus_ec_battery_prop_offs[psp];
+	if (!offs)
+		return -EINVAL;
+
+	ret = asus_ec_battery_refresh(priv);
+	if (ret < 0)
+		return ret;
+
+	if (offs >= priv->batt_data[0])
+		return -ENODATA;
+
+	return get_unaligned_le16(priv->batt_data + offs);
+}
+
+static int asus_ec_battery_get_property(struct power_supply *psy,
+					enum power_supply_property psp,
+					union power_supply_propval *val)
+{
+	struct asus_ec_battery_data *priv = power_supply_get_drvdata(psy);
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = 1;
+		break;
+
+	default:
+		ret = asus_ec_battery_get_value(priv, psp);
+		if (ret < 0)
+			return ret;
+
+		val->intval = (s16)ret;
+
+		switch (psp) {
+		case POWER_SUPPLY_PROP_STATUS:
+			if (ret & ASUSEC_BATTERY_FULL_CHARGED)
+				val->intval = POWER_SUPPLY_STATUS_FULL;
+			else if (ret & ASUSEC_BATTERY_NOT_CHARGING)
+				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+			else if (ret & ASUSEC_BATTERY_DISCHARGING)
+				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+			else
+				val->intval = POWER_SUPPLY_STATUS_CHARGING;
+			break;
+
+		case POWER_SUPPLY_PROP_TEMP:
+			val->intval -= TEMP_CELSIUS_OFFSET;
+			break;
+
+		case POWER_SUPPLY_PROP_CHARGE_NOW:
+		case POWER_SUPPLY_PROP_CURRENT_NOW:
+		case POWER_SUPPLY_PROP_CURRENT_MAX:
+		case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+			val->intval *= 1000;
+			break;
+
+		case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
+		case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
+			val->intval *= 60;
+			break;
+
+		default:
+			break;
+		}
+
+		break;
+	}
+
+	return 0;
+}
+
+static void asus_ec_battery_poll_work(struct work_struct *work)
+{
+	struct asus_ec_battery_data *priv =
+		container_of(work, struct asus_ec_battery_data, poll_work.work);
+	int state;
+
+	state = asus_ec_battery_get_value(priv, POWER_SUPPLY_PROP_STATUS);
+	if (state < 0)
+		return;
+
+	if (state & ASUSEC_BATTERY_FULL_CHARGED)
+		state = POWER_SUPPLY_STATUS_FULL;
+	else if (state & ASUSEC_BATTERY_DISCHARGING)
+		state = POWER_SUPPLY_STATUS_DISCHARGING;
+	else
+		state = POWER_SUPPLY_STATUS_CHARGING;
+
+	if (priv->last_state != state) {
+		priv->last_state = state;
+		power_supply_changed(priv->battery);
+	}
+
+	/* continuously send uevent notification */
+	schedule_delayed_work(&priv->poll_work,
+			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
+}
+
+static const struct power_supply_desc asus_ec_battery_desc = {
+	.name = "asus-ec-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = asus_ec_battery_properties,
+	.num_properties = ARRAY_SIZE(asus_ec_battery_properties),
+	.get_property = asus_ec_battery_get_property,
+	.external_power_changed = power_supply_changed,
+};
+
+static int asus_ec_battery_probe(struct platform_device *pdev)
+{
+	struct asus_ec_battery_data *priv;
+	struct device *dev = &pdev->dev;
+	struct power_supply_config cfg = { };
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	mutex_init(&priv->battery_lock);
+
+	priv->ec = cell_to_ec(pdev);
+	priv->batt_data_ts = jiffies - 1;
+	priv->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	cfg.fwnode = dev_fwnode(dev->parent);
+	cfg.drv_data = priv;
+
+	memcpy(&priv->psy_desc, &asus_ec_battery_desc, sizeof(priv->psy_desc));
+	priv->psy_desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s-battery",
+					     priv->ec->name);
+
+	priv->battery = devm_power_supply_register(dev, &priv->psy_desc, &cfg);
+	if (IS_ERR(priv->battery))
+		return dev_err_probe(dev, PTR_ERR(priv->battery),
+				     "Failed to register power supply\n");
+
+	ret = devm_delayed_work_autocancel(dev, &priv->poll_work,
+					   asus_ec_battery_poll_work);
+	if (ret)
+		return ret;
+
+	schedule_delayed_work(&priv->poll_work,
+			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
+
+	return 0;
+}
+
+static int __maybe_unused asus_ec_battery_suspend(struct device *dev)
+{
+	struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
+
+	cancel_delayed_work_sync(&priv->poll_work);
+
+	return 0;
+}
+
+static int __maybe_unused asus_ec_battery_resume(struct device *dev)
+{
+	struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
+
+	schedule_delayed_work(&priv->poll_work,
+			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(asus_ec_battery_pm_ops,
+			 asus_ec_battery_suspend, asus_ec_battery_resume);
+
+static struct platform_driver asus_ec_battery_driver = {
+	.driver = {
+		.name = "asus-transformer-ec-battery",
+		.pm = &asus_ec_battery_pm_ops,
+	},
+	.probe = asus_ec_battery_probe,
+};
+module_platform_driver(asus_ec_battery_driver);
+
+MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("ASUS Transformer's battery driver");
+MODULE_LICENSE("GPL");
-- 
2.51.0

Hi,

On Wed, Mar 04, 2026 at 08:57:50PM +0200, Svyatoslav Ryhel wrote:
> From: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> 
> Driver implements one battery cell per EC controller and supports reading
> of battery status for ASUS Transformer's pad and mobile dock.
> 
> Co-developed-by: Svyatoslav Ryhel <clamor95@gmail.com>
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---
>  drivers/power/supply/Kconfig                  |  11 +
>  drivers/power/supply/Makefile                 |   1 +
>  .../supply/asus-transformer-ec-battery.c      | 272 ++++++++++++++++++
>  3 files changed, 284 insertions(+)
>  create mode 100644 drivers/power/supply/asus-transformer-ec-battery.c
> 
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index 81fadb0695a9..3c46b412632d 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -122,6 +122,17 @@ config BATTERY_CHAGALL
>  	  This driver can also be built as a module. If so, the module will be
>  	  called chagall-battery.
>  
> +config BATTERY_ASUS_TRANSFORMER_EC
> +	tristate "Asus Transformer's battery driver"
> +	depends on MFD_ASUS_TRANSFORMER_EC
> +	help
> +	  Say Y here to enable support APM status emulation using
> +	  battery class devices.

^^^

You forgot to drop that when you used the APM_POWER config entry as
template. Otherwise the driver LGTM:

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Greetings,

-- Sebastian

> +	  This sub-driver supports battery cells found in Asus Transformer
> +	  tablets and mobile docks and controlled by special embedded
> +	  controller.
> +
>  config BATTERY_CPCAP
>  	tristate "Motorola CPCAP PMIC battery driver"
>  	depends on MFD_CPCAP && IIO
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 41c400bbf022..aa5e6b05b018 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_TEST_POWER)	+= test_power.o
>  obj-$(CONFIG_BATTERY_88PM860X)	+= 88pm860x_battery.o
>  obj-$(CONFIG_CHARGER_ADP5061)	+= adp5061.o
>  obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
> +obj-$(CONFIG_BATTERY_ASUS_TRANSFORMER_EC)	+= asus-transformer-ec-battery.o
>  obj-$(CONFIG_BATTERY_AXP20X)	+= axp20x_battery.o
>  obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
>  obj-$(CONFIG_BATTERY_CHAGALL)	+= chagall-battery.o
> diff --git a/drivers/power/supply/asus-transformer-ec-battery.c b/drivers/power/supply/asus-transformer-ec-battery.c
> new file mode 100644
> index 000000000000..aefcd3fed6fe
> --- /dev/null
> +++ b/drivers/power/supply/asus-transformer-ec-battery.c
> @@ -0,0 +1,272 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/array_size.h>
> +#include <linux/devm-helpers.h>
> +#include <linux/err.h>
> +#include <linux/mfd/asus-transformer-ec.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/property.h>
> +#include <linux/unaligned.h>
> +
> +#define ASUSEC_BATTERY_DATA_FRESH_MSEC		5000
> +
> +#define ASUSEC_BATTERY_DISCHARGING		0x40
> +#define ASUSEC_BATTERY_FULL_CHARGED		0x20
> +#define ASUSEC_BATTERY_NOT_CHARGING		0x10
> +
> +#define TEMP_CELSIUS_OFFSET			2731
> +
> +struct asus_ec_battery_data {
> +	const struct asusec_info *ec;
> +	struct power_supply *battery;
> +	struct power_supply_desc psy_desc;
> +	struct delayed_work poll_work;
> +	struct mutex battery_lock; /* for data refresh */
> +	unsigned long batt_data_ts;
> +	int last_state;
> +	u8 batt_data[DOCKRAM_ENTRY_BUFSIZE];
> +};
> +
> +static int asus_ec_battery_refresh(struct asus_ec_battery_data *priv)
> +{
> +	int ret = 0;
> +
> +	guard(mutex)(&priv->battery_lock);
> +
> +	if (time_before(jiffies, priv->batt_data_ts))
> +		return ret;
> +
> +	ret = asus_dockram_read(priv->ec->dockram, ASUSEC_DOCKRAM_BATT_CTL,
> +				priv->batt_data);
> +	if (ret < 0)
> +		return ret;
> +
> +	priv->batt_data_ts = jiffies +
> +		msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC);
> +
> +	return ret;
> +}
> +
> +static enum power_supply_property asus_ec_battery_properties[] = {
> +	POWER_SUPPLY_PROP_STATUS,
> +	POWER_SUPPLY_PROP_VOLTAGE_MAX,
> +	POWER_SUPPLY_PROP_CURRENT_MAX,
> +	POWER_SUPPLY_PROP_TEMP,
> +	POWER_SUPPLY_PROP_VOLTAGE_NOW,
> +	POWER_SUPPLY_PROP_CURRENT_NOW,
> +	POWER_SUPPLY_PROP_CAPACITY,
> +	POWER_SUPPLY_PROP_CHARGE_NOW,
> +	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
> +	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
> +	POWER_SUPPLY_PROP_PRESENT,
> +};
> +
> +static const unsigned int asus_ec_battery_prop_offs[] = {
> +	[POWER_SUPPLY_PROP_STATUS] = 1,
> +	[POWER_SUPPLY_PROP_VOLTAGE_MAX] = 3,
> +	[POWER_SUPPLY_PROP_CURRENT_MAX] = 5,
> +	[POWER_SUPPLY_PROP_TEMP] = 7,
> +	[POWER_SUPPLY_PROP_VOLTAGE_NOW] = 9,
> +	[POWER_SUPPLY_PROP_CURRENT_NOW] = 11,
> +	[POWER_SUPPLY_PROP_CAPACITY] = 13,
> +	[POWER_SUPPLY_PROP_CHARGE_NOW] = 15,
> +	[POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW] = 17,
> +	[POWER_SUPPLY_PROP_TIME_TO_FULL_NOW] = 19,
> +};
> +
> +static int asus_ec_battery_get_value(struct asus_ec_battery_data *priv,
> +				     enum power_supply_property psp)
> +{
> +	int ret, offs;
> +
> +	if (psp >= ARRAY_SIZE(asus_ec_battery_prop_offs))
> +		return -EINVAL;
> +
> +	offs = asus_ec_battery_prop_offs[psp];
> +	if (!offs)
> +		return -EINVAL;
> +
> +	ret = asus_ec_battery_refresh(priv);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (offs >= priv->batt_data[0])
> +		return -ENODATA;
> +
> +	return get_unaligned_le16(priv->batt_data + offs);
> +}
> +
> +static int asus_ec_battery_get_property(struct power_supply *psy,
> +					enum power_supply_property psp,
> +					union power_supply_propval *val)
> +{
> +	struct asus_ec_battery_data *priv = power_supply_get_drvdata(psy);
> +	int ret;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_PRESENT:
> +		val->intval = 1;
> +		break;
> +
> +	default:
> +		ret = asus_ec_battery_get_value(priv, psp);
> +		if (ret < 0)
> +			return ret;
> +
> +		val->intval = (s16)ret;
> +
> +		switch (psp) {
> +		case POWER_SUPPLY_PROP_STATUS:
> +			if (ret & ASUSEC_BATTERY_FULL_CHARGED)
> +				val->intval = POWER_SUPPLY_STATUS_FULL;
> +			else if (ret & ASUSEC_BATTERY_NOT_CHARGING)
> +				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +			else if (ret & ASUSEC_BATTERY_DISCHARGING)
> +				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> +			else
> +				val->intval = POWER_SUPPLY_STATUS_CHARGING;
> +			break;
> +
> +		case POWER_SUPPLY_PROP_TEMP:
> +			val->intval -= TEMP_CELSIUS_OFFSET;
> +			break;
> +
> +		case POWER_SUPPLY_PROP_CHARGE_NOW:
> +		case POWER_SUPPLY_PROP_CURRENT_NOW:
> +		case POWER_SUPPLY_PROP_CURRENT_MAX:
> +		case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> +		case POWER_SUPPLY_PROP_VOLTAGE_MAX:
> +			val->intval *= 1000;
> +			break;
> +
> +		case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
> +		case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
> +			val->intval *= 60;
> +			break;
> +
> +		default:
> +			break;
> +		}
> +
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static void asus_ec_battery_poll_work(struct work_struct *work)
> +{
> +	struct asus_ec_battery_data *priv =
> +		container_of(work, struct asus_ec_battery_data, poll_work.work);
> +	int state;
> +
> +	state = asus_ec_battery_get_value(priv, POWER_SUPPLY_PROP_STATUS);
> +	if (state < 0)
> +		return;
> +
> +	if (state & ASUSEC_BATTERY_FULL_CHARGED)
> +		state = POWER_SUPPLY_STATUS_FULL;
> +	else if (state & ASUSEC_BATTERY_DISCHARGING)
> +		state = POWER_SUPPLY_STATUS_DISCHARGING;
> +	else
> +		state = POWER_SUPPLY_STATUS_CHARGING;
> +
> +	if (priv->last_state != state) {
> +		priv->last_state = state;
> +		power_supply_changed(priv->battery);
> +	}
> +
> +	/* continuously send uevent notification */
> +	schedule_delayed_work(&priv->poll_work,
> +			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> +}
> +
> +static const struct power_supply_desc asus_ec_battery_desc = {
> +	.name = "asus-ec-battery",
> +	.type = POWER_SUPPLY_TYPE_BATTERY,
> +	.properties = asus_ec_battery_properties,
> +	.num_properties = ARRAY_SIZE(asus_ec_battery_properties),
> +	.get_property = asus_ec_battery_get_property,
> +	.external_power_changed = power_supply_changed,
> +};
> +
> +static int asus_ec_battery_probe(struct platform_device *pdev)
> +{
> +	struct asus_ec_battery_data *priv;
> +	struct device *dev = &pdev->dev;
> +	struct power_supply_config cfg = { };
> +	int ret;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	mutex_init(&priv->battery_lock);
> +
> +	priv->ec = cell_to_ec(pdev);
> +	priv->batt_data_ts = jiffies - 1;
> +	priv->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
> +
> +	cfg.fwnode = dev_fwnode(dev->parent);
> +	cfg.drv_data = priv;
> +
> +	memcpy(&priv->psy_desc, &asus_ec_battery_desc, sizeof(priv->psy_desc));
> +	priv->psy_desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s-battery",
> +					     priv->ec->name);
> +
> +	priv->battery = devm_power_supply_register(dev, &priv->psy_desc, &cfg);
> +	if (IS_ERR(priv->battery))
> +		return dev_err_probe(dev, PTR_ERR(priv->battery),
> +				     "Failed to register power supply\n");
> +
> +	ret = devm_delayed_work_autocancel(dev, &priv->poll_work,
> +					   asus_ec_battery_poll_work);
> +	if (ret)
> +		return ret;
> +
> +	schedule_delayed_work(&priv->poll_work,
> +			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused asus_ec_battery_suspend(struct device *dev)
> +{
> +	struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
> +
> +	cancel_delayed_work_sync(&priv->poll_work);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused asus_ec_battery_resume(struct device *dev)
> +{
> +	struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
> +
> +	schedule_delayed_work(&priv->poll_work,
> +			      msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(asus_ec_battery_pm_ops,
> +			 asus_ec_battery_suspend, asus_ec_battery_resume);
> +
> +static struct platform_driver asus_ec_battery_driver = {
> +	.driver = {
> +		.name = "asus-transformer-ec-battery",
> +		.pm = &asus_ec_battery_pm_ops,
> +	},
> +	.probe = asus_ec_battery_probe,
> +};
> +module_platform_driver(asus_ec_battery_driver);
> +
> +MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
> +MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
> +MODULE_DESCRIPTION("ASUS Transformer's battery driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.51.0
> 
> 

ср, 11 бер. 2026 р. о 08:31 Sebastian Reichel
<sebastian.reichel@collabora.com> пише:
>
> Hi,
>
> On Wed, Mar 04, 2026 at 08:57:50PM +0200, Svyatoslav Ryhel wrote:
> > From: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> >
> > Driver implements one battery cell per EC controller and supports reading
> > of battery status for ASUS Transformer's pad and mobile dock.
> >
> > Co-developed-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> > ---
> >  drivers/power/supply/Kconfig                  |  11 +
> >  drivers/power/supply/Makefile                 |   1 +
> >  .../supply/asus-transformer-ec-battery.c      | 272 ++++++++++++++++++
> >  3 files changed, 284 insertions(+)
> >  create mode 100644 drivers/power/supply/asus-transformer-ec-battery.c
> >
> > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> > index 81fadb0695a9..3c46b412632d 100644
> > --- a/drivers/power/supply/Kconfig
> > +++ b/drivers/power/supply/Kconfig
> > @@ -122,6 +122,17 @@ config BATTERY_CHAGALL
> >         This driver can also be built as a module. If so, the module will be
> >         called chagall-battery.
> >
> > +config BATTERY_ASUS_TRANSFORMER_EC
> > +     tristate "Asus Transformer's battery driver"
> > +     depends on MFD_ASUS_TRANSFORMER_EC
> > +     help
> > +       Say Y here to enable support APM status emulation using
> > +       battery class devices.
>
> ^^^
>
> You forgot to drop that when you used the APM_POWER config entry as
> template. Otherwise the driver LGTM:
>

Oh, my bad. I will adjust in the next iteration. Thank you catching this.

> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>
> Greetings,
>
> -- Sebastian
>
> > +       This sub-driver supports battery cells found in Asus Transformer
> > +       tablets and mobile docks and controlled by special embedded
> > +       controller.
> > +
> >  config BATTERY_CPCAP
> >       tristate "Motorola CPCAP PMIC battery driver"
> >       depends on MFD_CPCAP && IIO
> > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> > index 41c400bbf022..aa5e6b05b018 100644
> > --- a/drivers/power/supply/Makefile
> > +++ b/drivers/power/supply/Makefile
> > @@ -22,6 +22,7 @@ obj-$(CONFIG_TEST_POWER)    += test_power.o
> >  obj-$(CONFIG_BATTERY_88PM860X)       += 88pm860x_battery.o
> >  obj-$(CONFIG_CHARGER_ADP5061)        += adp5061.o
> >  obj-$(CONFIG_BATTERY_ACT8945A)       += act8945a_charger.o
> > +obj-$(CONFIG_BATTERY_ASUS_TRANSFORMER_EC)    += asus-transformer-ec-battery.o
> >  obj-$(CONFIG_BATTERY_AXP20X) += axp20x_battery.o
> >  obj-$(CONFIG_CHARGER_AXP20X) += axp20x_ac_power.o
> >  obj-$(CONFIG_BATTERY_CHAGALL)        += chagall-battery.o
> > diff --git a/drivers/power/supply/asus-transformer-ec-battery.c b/drivers/power/supply/asus-transformer-ec-battery.c
> > new file mode 100644
> > index 000000000000..aefcd3fed6fe
> > --- /dev/null
> > +++ b/drivers/power/supply/asus-transformer-ec-battery.c
> > @@ -0,0 +1,272 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +
> > +#include <linux/array_size.h>
> > +#include <linux/devm-helpers.h>
> > +#include <linux/err.h>
> > +#include <linux/mfd/asus-transformer-ec.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/power_supply.h>
> > +#include <linux/property.h>
> > +#include <linux/unaligned.h>
> > +
> > +#define ASUSEC_BATTERY_DATA_FRESH_MSEC               5000
> > +
> > +#define ASUSEC_BATTERY_DISCHARGING           0x40
> > +#define ASUSEC_BATTERY_FULL_CHARGED          0x20
> > +#define ASUSEC_BATTERY_NOT_CHARGING          0x10
> > +
> > +#define TEMP_CELSIUS_OFFSET                  2731
> > +
> > +struct asus_ec_battery_data {
> > +     const struct asusec_info *ec;
> > +     struct power_supply *battery;
> > +     struct power_supply_desc psy_desc;
> > +     struct delayed_work poll_work;
> > +     struct mutex battery_lock; /* for data refresh */
> > +     unsigned long batt_data_ts;
> > +     int last_state;
> > +     u8 batt_data[DOCKRAM_ENTRY_BUFSIZE];
> > +};
> > +
> > +static int asus_ec_battery_refresh(struct asus_ec_battery_data *priv)
> > +{
> > +     int ret = 0;
> > +
> > +     guard(mutex)(&priv->battery_lock);
> > +
> > +     if (time_before(jiffies, priv->batt_data_ts))
> > +             return ret;
> > +
> > +     ret = asus_dockram_read(priv->ec->dockram, ASUSEC_DOCKRAM_BATT_CTL,
> > +                             priv->batt_data);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     priv->batt_data_ts = jiffies +
> > +             msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC);
> > +
> > +     return ret;
> > +}
> > +
> > +static enum power_supply_property asus_ec_battery_properties[] = {
> > +     POWER_SUPPLY_PROP_STATUS,
> > +     POWER_SUPPLY_PROP_VOLTAGE_MAX,
> > +     POWER_SUPPLY_PROP_CURRENT_MAX,
> > +     POWER_SUPPLY_PROP_TEMP,
> > +     POWER_SUPPLY_PROP_VOLTAGE_NOW,
> > +     POWER_SUPPLY_PROP_CURRENT_NOW,
> > +     POWER_SUPPLY_PROP_CAPACITY,
> > +     POWER_SUPPLY_PROP_CHARGE_NOW,
> > +     POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
> > +     POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
> > +     POWER_SUPPLY_PROP_PRESENT,
> > +};
> > +
> > +static const unsigned int asus_ec_battery_prop_offs[] = {
> > +     [POWER_SUPPLY_PROP_STATUS] = 1,
> > +     [POWER_SUPPLY_PROP_VOLTAGE_MAX] = 3,
> > +     [POWER_SUPPLY_PROP_CURRENT_MAX] = 5,
> > +     [POWER_SUPPLY_PROP_TEMP] = 7,
> > +     [POWER_SUPPLY_PROP_VOLTAGE_NOW] = 9,
> > +     [POWER_SUPPLY_PROP_CURRENT_NOW] = 11,
> > +     [POWER_SUPPLY_PROP_CAPACITY] = 13,
> > +     [POWER_SUPPLY_PROP_CHARGE_NOW] = 15,
> > +     [POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW] = 17,
> > +     [POWER_SUPPLY_PROP_TIME_TO_FULL_NOW] = 19,
> > +};
> > +
> > +static int asus_ec_battery_get_value(struct asus_ec_battery_data *priv,
> > +                                  enum power_supply_property psp)
> > +{
> > +     int ret, offs;
> > +
> > +     if (psp >= ARRAY_SIZE(asus_ec_battery_prop_offs))
> > +             return -EINVAL;
> > +
> > +     offs = asus_ec_battery_prop_offs[psp];
> > +     if (!offs)
> > +             return -EINVAL;
> > +
> > +     ret = asus_ec_battery_refresh(priv);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     if (offs >= priv->batt_data[0])
> > +             return -ENODATA;
> > +
> > +     return get_unaligned_le16(priv->batt_data + offs);
> > +}
> > +
> > +static int asus_ec_battery_get_property(struct power_supply *psy,
> > +                                     enum power_supply_property psp,
> > +                                     union power_supply_propval *val)
> > +{
> > +     struct asus_ec_battery_data *priv = power_supply_get_drvdata(psy);
> > +     int ret;
> > +
> > +     switch (psp) {
> > +     case POWER_SUPPLY_PROP_PRESENT:
> > +             val->intval = 1;
> > +             break;
> > +
> > +     default:
> > +             ret = asus_ec_battery_get_value(priv, psp);
> > +             if (ret < 0)
> > +                     return ret;
> > +
> > +             val->intval = (s16)ret;
> > +
> > +             switch (psp) {
> > +             case POWER_SUPPLY_PROP_STATUS:
> > +                     if (ret & ASUSEC_BATTERY_FULL_CHARGED)
> > +                             val->intval = POWER_SUPPLY_STATUS_FULL;
> > +                     else if (ret & ASUSEC_BATTERY_NOT_CHARGING)
> > +                             val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > +                     else if (ret & ASUSEC_BATTERY_DISCHARGING)
> > +                             val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> > +                     else
> > +                             val->intval = POWER_SUPPLY_STATUS_CHARGING;
> > +                     break;
> > +
> > +             case POWER_SUPPLY_PROP_TEMP:
> > +                     val->intval -= TEMP_CELSIUS_OFFSET;
> > +                     break;
> > +
> > +             case POWER_SUPPLY_PROP_CHARGE_NOW:
> > +             case POWER_SUPPLY_PROP_CURRENT_NOW:
> > +             case POWER_SUPPLY_PROP_CURRENT_MAX:
> > +             case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> > +             case POWER_SUPPLY_PROP_VOLTAGE_MAX:
> > +                     val->intval *= 1000;
> > +                     break;
> > +
> > +             case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
> > +             case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
> > +                     val->intval *= 60;
> > +                     break;
> > +
> > +             default:
> > +                     break;
> > +             }
> > +
> > +             break;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void asus_ec_battery_poll_work(struct work_struct *work)
> > +{
> > +     struct asus_ec_battery_data *priv =
> > +             container_of(work, struct asus_ec_battery_data, poll_work.work);
> > +     int state;
> > +
> > +     state = asus_ec_battery_get_value(priv, POWER_SUPPLY_PROP_STATUS);
> > +     if (state < 0)
> > +             return;
> > +
> > +     if (state & ASUSEC_BATTERY_FULL_CHARGED)
> > +             state = POWER_SUPPLY_STATUS_FULL;
> > +     else if (state & ASUSEC_BATTERY_DISCHARGING)
> > +             state = POWER_SUPPLY_STATUS_DISCHARGING;
> > +     else
> > +             state = POWER_SUPPLY_STATUS_CHARGING;
> > +
> > +     if (priv->last_state != state) {
> > +             priv->last_state = state;
> > +             power_supply_changed(priv->battery);
> > +     }
> > +
> > +     /* continuously send uevent notification */
> > +     schedule_delayed_work(&priv->poll_work,
> > +                           msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> > +}
> > +
> > +static const struct power_supply_desc asus_ec_battery_desc = {
> > +     .name = "asus-ec-battery",
> > +     .type = POWER_SUPPLY_TYPE_BATTERY,
> > +     .properties = asus_ec_battery_properties,
> > +     .num_properties = ARRAY_SIZE(asus_ec_battery_properties),
> > +     .get_property = asus_ec_battery_get_property,
> > +     .external_power_changed = power_supply_changed,
> > +};
> > +
> > +static int asus_ec_battery_probe(struct platform_device *pdev)
> > +{
> > +     struct asus_ec_battery_data *priv;
> > +     struct device *dev = &pdev->dev;
> > +     struct power_supply_config cfg = { };
> > +     int ret;
> > +
> > +     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +     if (!priv)
> > +             return -ENOMEM;
> > +
> > +     platform_set_drvdata(pdev, priv);
> > +
> > +     mutex_init(&priv->battery_lock);
> > +
> > +     priv->ec = cell_to_ec(pdev);
> > +     priv->batt_data_ts = jiffies - 1;
> > +     priv->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
> > +
> > +     cfg.fwnode = dev_fwnode(dev->parent);
> > +     cfg.drv_data = priv;
> > +
> > +     memcpy(&priv->psy_desc, &asus_ec_battery_desc, sizeof(priv->psy_desc));
> > +     priv->psy_desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s-battery",
> > +                                          priv->ec->name);
> > +
> > +     priv->battery = devm_power_supply_register(dev, &priv->psy_desc, &cfg);
> > +     if (IS_ERR(priv->battery))
> > +             return dev_err_probe(dev, PTR_ERR(priv->battery),
> > +                                  "Failed to register power supply\n");
> > +
> > +     ret = devm_delayed_work_autocancel(dev, &priv->poll_work,
> > +                                        asus_ec_battery_poll_work);
> > +     if (ret)
> > +             return ret;
> > +
> > +     schedule_delayed_work(&priv->poll_work,
> > +                           msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> > +
> > +     return 0;
> > +}
> > +
> > +static int __maybe_unused asus_ec_battery_suspend(struct device *dev)
> > +{
> > +     struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
> > +
> > +     cancel_delayed_work_sync(&priv->poll_work);
> > +
> > +     return 0;
> > +}
> > +
> > +static int __maybe_unused asus_ec_battery_resume(struct device *dev)
> > +{
> > +     struct asus_ec_battery_data *priv = dev_get_drvdata(dev);
> > +
> > +     schedule_delayed_work(&priv->poll_work,
> > +                           msecs_to_jiffies(ASUSEC_BATTERY_DATA_FRESH_MSEC));
> > +
> > +     return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(asus_ec_battery_pm_ops,
> > +                      asus_ec_battery_suspend, asus_ec_battery_resume);
> > +
> > +static struct platform_driver asus_ec_battery_driver = {
> > +     .driver = {
> > +             .name = "asus-transformer-ec-battery",
> > +             .pm = &asus_ec_battery_pm_ops,
> > +     },
> > +     .probe = asus_ec_battery_probe,
> > +};
> > +module_platform_driver(asus_ec_battery_driver);
> > +
> > +MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
> > +MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
> > +MODULE_DESCRIPTION("ASUS Transformer's battery driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.51.0
> >
> >