Message-Id: <20240614-yoga-ec-driver-v7-4-9f0b9b40ae76@linaro.org>
Date: Fri, 14 Jun 2024 02:43:41 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Bjorn Andersson <andersson@...nel.org>, 
 Hans de Goede <hdegoede@...hat.com>, 
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
 Bryan O'Donoghue <bryan.odonoghue@...aro.org>, 
 Heikki Krogerus <heikki.krogerus@...ux.intel.com>, 
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 Konrad Dybcio <konrad.dybcio@...aro.org>
Cc: linux-pm@...r.kernel.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, platform-driver-x86@...r.kernel.org, 
 linux-usb@...r.kernel.org, linux-arm-msm@...r.kernel.org, 
 Nikita Travkin <nikita@...n.ru>
Subject: [PATCH v7 4/6] power: supply: lenovo_yoga_c630_battery: add Lenovo
 C630 driver

On the Lenovo Yoga C630 WOS laptop the EC provides access to the adapter
and battery status. Add the driver to read power supply status on the
laptop.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
---
 drivers/power/supply/Kconfig                    |   9 +
 drivers/power/supply/Makefile                   |   1 +
 drivers/power/supply/lenovo_yoga_c630_battery.c | 500 ++++++++++++++++++++++++
 3 files changed, 510 insertions(+)

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 3e31375491d5..55ab8e90747d 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -167,6 +167,15 @@ config BATTERY_LEGO_EV3
 	help
 	  Say Y here to enable support for the LEGO MINDSTORMS EV3 battery.
 
+config BATTERY_LENOVO_YOGA_C630
+	tristate "Lenovo Yoga C630 battery"
+	depends on OF && EC_LENOVO_YOGA_C630
+	help
+	  This driver enables battery support on the Lenovo Yoga C630 laptop.
+
+	  To compile the driver as a module, choose M here: the module will be
+	  called lenovo_yoga_c630_battery.
+
 config BATTERY_PMU
 	tristate "Apple PMU battery"
 	depends on PPC32 && ADB_PMU
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 58b567278034..8ebbdcf92dac 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_BATTERY_DS2782)	+= ds2782_battery.o
 obj-$(CONFIG_BATTERY_GAUGE_LTC2941)	+= ltc2941-battery-gauge.o
 obj-$(CONFIG_BATTERY_GOLDFISH)	+= goldfish_battery.o
 obj-$(CONFIG_BATTERY_LEGO_EV3)	+= lego_ev3_battery.o
+obj-$(CONFIG_BATTERY_LENOVO_YOGA_C630) += lenovo_yoga_c630_battery.o
 obj-$(CONFIG_BATTERY_PMU)	+= pmu_battery.o
 obj-$(CONFIG_BATTERY_QCOM_BATTMGR)	+= qcom_battmgr.o
 obj-$(CONFIG_BATTERY_OLPC)	+= olpc_battery.o
diff --git a/drivers/power/supply/lenovo_yoga_c630_battery.c b/drivers/power/supply/lenovo_yoga_c630_battery.c
new file mode 100644
index 000000000000..0209cdb5546f
--- /dev/null
+++ b/drivers/power/supply/lenovo_yoga_c630_battery.c
@@ -0,0 +1,500 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2024, Linaro Ltd
+ * Authors:
+ *    Bjorn Andersson
+ *    Dmitry Baryshkov
+ */
+#include <linux/auxiliary_bus.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/power_supply.h>
+#include <linux/platform_data/lenovo-yoga-c630.h>
+
+struct yoga_c630_psy {
+	struct yoga_c630_ec *ec;
+	struct device *dev;
+	struct fwnode_handle *fwnode;
+	struct notifier_block nb;
+
+	/* guards all battery properties and registration of power supplies */
+	struct mutex lock;
+
+	struct power_supply *adp_psy;
+	struct power_supply *bat_psy;
+
+	unsigned long last_status_update;
+
+	bool adapter_online;
+
+	bool unit_mA;
+
+	bool bat_present;
+	unsigned int bat_status;
+	unsigned int design_capacity;
+	unsigned int design_voltage;
+	unsigned int full_charge_capacity;
+
+	unsigned int capacity_now;
+	unsigned int voltage_now;
+
+	int current_now;
+	int rate_now;
+};
+
+#define LENOVO_EC_CACHE_TIME		(10 * HZ)
+
+#define LENOVO_EC_ADPT_STATUS		0xa3
+#define LENOVO_EC_ADPT_STATUS_PRESENT		BIT(7)
+#define LENOVO_EC_BAT_ATTRIBUTES	0xc0
+#define LENOVO_EC_BAT_ATTRIBUTES_UNIT_IS_MA	BIT(1)
+#define LENOVO_EC_BAT_STATUS		0xc1
+#define LENOVO_EC_BAT_STATUS_DISCHARGING	BIT(0)
+#define LENOVO_EC_BAT_STATUS_CHARGING		BIT(1)
+#define LENOVO_EC_BAT_REMAIN_CAPACITY	0xc2
+#define LENOVO_EC_BAT_VOLTAGE		0xc6
+#define LENOVO_EC_BAT_DESIGN_VOLTAGE	0xc8
+#define LENOVO_EC_BAT_DESIGN_CAPACITY	0xca
+#define LENOVO_EC_BAT_FULL_CAPACITY	0xcc
+#define LENOVO_EC_BAT_CURRENT		0xd2
+#define LENOVO_EC_BAT_FULL_FACTORY	0xd6
+#define LENOVO_EC_BAT_PRESENT		0xda
+#define LENOVO_EC_BAT_PRESENT_IS_PRESENT	BIT(0)
+#define LENOVO_EC_BAT_FULL_REGISTER	0xdb
+#define LENOVO_EC_BAT_FULL_REGISTER_IS_FACTORY	BIT(0)
+
+static int yoga_c630_psy_update_bat_info(struct yoga_c630_psy *ecbat)
+{
+	struct yoga_c630_ec *ec = ecbat->ec;
+	int val;
+
+	lockdep_assert_held(&ecbat->lock);
+
+	val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_PRESENT);
+	if (val < 0)
+		return val;
+	ecbat->bat_present = !!(val & LENOVO_EC_BAT_PRESENT_IS_PRESENT);
+	if (!ecbat->bat_present)
+		return val;
+
+	val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_ATTRIBUTES);
+	if (val < 0)
+		return val;
+	ecbat->unit_mA = val & LENOVO_EC_BAT_ATTRIBUTES_UNIT_IS_MA;
+
+	val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_DESIGN_CAPACITY);
+	if (val < 0)
+		return val;
+	ecbat->design_capacity = val * 1000;
+
+	/*
+	 * DSDT has delays after most of EC reads in these methods.
+	 * Having no documentation for the EC we have to follow and sleep here.
+	 */
+	msleep(50);
+
+	val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_DESIGN_VOLTAGE);
+	if (val < 0)
+		return val;
+	ecbat->design_voltage = val;
+
+	msleep(50);
+
+	val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_FULL_REGISTER);
+	if (val < 0)
+		return val;
+	val = yoga_c630_ec_read16(ec,
+				  val & LENOVO_EC_BAT_FULL_REGISTER_IS_FACTORY ?
+				  LENOVO_EC_BAT_FULL_FACTORY :
+				  LENOVO_EC_BAT_FULL_CAPACITY);
+	if (val < 0)
+		return val;
+
+	ecbat->full_charge_capacity = val * 1000;
+
+	if (!ecbat->unit_mA) {
+		ecbat->design_capacity *= 10;
+		ecbat->full_charge_capacity *= 10;
+	}
+
+	return 0;
+}
+
+static int yoga_c630_psy_maybe_update_bat_status(struct yoga_c630_psy *ecbat)
+{
+	struct yoga_c630_ec *ec = ecbat->ec;
+	int current_mA;
+	int val;
+
+	guard(mutex)(&ecbat->lock);
+	if (time_before(jiffies, ecbat->last_status_update + LENOVO_EC_CACHE_TIME))
+		return 0;
+
+	val = yoga_c630_ec_read8(ec, LENOVO_EC_BAT_STATUS);
+	if (val < 0)
+		return val;
+	ecbat->bat_status = val;
+
+	msleep(50);
+
+	val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_REMAIN_CAPACITY);
+	if (val < 0)
+		return val;
+	ecbat->capacity_now = val * 1000;
+
+	msleep(50);
+
+	val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_VOLTAGE);
+	if (val < 0)
+		return val;
+	ecbat->voltage_now = val * 1000;
+
+	msleep(50);
+
+	val = yoga_c630_ec_read16(ec, LENOVO_EC_BAT_CURRENT);
+	if (val < 0)
+		return val;
+	current_mA = sign_extend32(val, 15);
+	ecbat->current_now = current_mA * 1000;
+	ecbat->rate_now = current_mA * (ecbat->voltage_now / 1000);
+
+	msleep(50);
+
+	if (!ecbat->unit_mA)
+		ecbat->capacity_now *= 10;
+
+	ecbat->last_status_update = jiffies;
+
+	return 0;
+}
+
+static int yoga_c630_psy_update_adapter_status(struct yoga_c630_psy *ecbat)
+{
+	struct yoga_c630_ec *ec = ecbat->ec;
+	int val;
+
+	guard(mutex)(&ecbat->lock);
+
+	val = yoga_c630_ec_read8(ec, LENOVO_EC_ADPT_STATUS);
+	if (val < 0)
+		return val;
+
+	ecbat->adapter_online = !!(val & LENOVO_EC_ADPT_STATUS_PRESENT);
+
+	return 0;
+}
+
+static bool yoga_c630_psy_is_charged(struct yoga_c630_psy *ecbat)
+{
+	if (ecbat->bat_status != 0)
+		return false;
+
+	if (ecbat->full_charge_capacity <= ecbat->capacity_now)
+		return true;
+
+	if (ecbat->design_capacity <= ecbat->capacity_now)
+		return true;
+
+	return false;
+}
+
+static int yoga_c630_psy_bat_get_property(struct power_supply *psy,
+					 enum power_supply_property psp,
+					 union power_supply_propval *val)
+{
+	struct yoga_c630_psy *ecbat = power_supply_get_drvdata(psy);
+	int rc = 0;
+
+	if (!ecbat->bat_present && psp != POWER_SUPPLY_PROP_PRESENT)
+		return -ENODEV;
+
+	rc = yoga_c630_psy_maybe_update_bat_status(ecbat);
+	if (rc)
+		return rc;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (ecbat->bat_status & LENOVO_EC_BAT_STATUS_DISCHARGING)
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (ecbat->bat_status & LENOVO_EC_BAT_STATUS_CHARGING)
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else if (yoga_c630_psy_is_charged(ecbat))
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+		else
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = ecbat->bat_present;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		val->intval = ecbat->design_voltage;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+		val->intval = ecbat->design_capacity;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+	case POWER_SUPPLY_PROP_ENERGY_FULL:
+		val->intval = ecbat->full_charge_capacity;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+	case POWER_SUPPLY_PROP_ENERGY_NOW:
+		val->intval = ecbat->capacity_now;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		val->intval = ecbat->current_now;
+		break;
+	case POWER_SUPPLY_PROP_POWER_NOW:
+		val->intval = ecbat->rate_now;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		val->intval = ecbat->voltage_now;
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = "PABAS0241231";
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = "Compal";
+		break;
+	case POWER_SUPPLY_PROP_SCOPE:
+		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+
+	return rc;
+}
+
+static enum power_supply_property yoga_c630_psy_bat_mA_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_POWER_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SCOPE,
+};
+
+static enum power_supply_property yoga_c630_psy_bat_mWh_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+	POWER_SUPPLY_PROP_ENERGY_FULL,
+	POWER_SUPPLY_PROP_ENERGY_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_POWER_NOW,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SCOPE,
+};
+
+static const struct power_supply_desc yoga_c630_psy_bat_psy_desc_mA = {
+	.name = "yoga-c630-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = yoga_c630_psy_bat_mA_properties,
+	.num_properties = ARRAY_SIZE(yoga_c630_psy_bat_mA_properties),
+	.get_property = yoga_c630_psy_bat_get_property,
+};
+
+static const struct power_supply_desc yoga_c630_psy_bat_psy_desc_mWh = {
+	.name = "yoga-c630-battery",
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = yoga_c630_psy_bat_mWh_properties,
+	.num_properties = ARRAY_SIZE(yoga_c630_psy_bat_mWh_properties),
+	.get_property = yoga_c630_psy_bat_get_property,
+};
+
+static int yoga_c630_psy_adpt_get_property(struct power_supply *psy,
+					  enum power_supply_property psp,
+					  union power_supply_propval *val)
+{
+	struct yoga_c630_psy *ecbat = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	ret = yoga_c630_psy_update_adapter_status(ecbat);
+	if (ret < 0)
+		return ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_ONLINE:
+		val->intval = ecbat->adapter_online;
+		break;
+	case POWER_SUPPLY_PROP_USB_TYPE:
+		val->intval = POWER_SUPPLY_USB_TYPE_C;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static enum power_supply_property yoga_c630_psy_adpt_properties[] = {
+	POWER_SUPPLY_PROP_ONLINE,
+	POWER_SUPPLY_PROP_USB_TYPE,
+};
+
+static const enum power_supply_usb_type yoga_c630_psy_adpt_usb_type[] = {
+	POWER_SUPPLY_USB_TYPE_C,
+};
+
+static const struct power_supply_desc yoga_c630_psy_adpt_psy_desc = {
+	.name = "yoga-c630-adapter",
+	.type = POWER_SUPPLY_TYPE_USB,
+	.usb_types = yoga_c630_psy_adpt_usb_type,
+	.num_usb_types = ARRAY_SIZE(yoga_c630_psy_adpt_usb_type),
+	.properties = yoga_c630_psy_adpt_properties,
+	.num_properties = ARRAY_SIZE(yoga_c630_psy_adpt_properties),
+	.get_property = yoga_c630_psy_adpt_get_property,
+};
+
+static int yoga_c630_psy_register_bat_psy(struct yoga_c630_psy *ecbat)
+{
+	struct power_supply_config bat_cfg = {};
+
+	bat_cfg.drv_data = ecbat;
+	bat_cfg.fwnode = ecbat->fwnode;
+	ecbat->bat_psy = power_supply_register_no_ws(ecbat->dev,
+						     ecbat->unit_mA ?
+						     &yoga_c630_psy_bat_psy_desc_mA :
+						     &yoga_c630_psy_bat_psy_desc_mWh,
+						     &bat_cfg);
+	if (IS_ERR(ecbat->bat_psy)) {
+		dev_err(ecbat->dev, "failed to register battery supply\n");
+		return PTR_ERR(ecbat->bat_psy);
+	}
+
+	return 0;
+}
+
+static void yoga_c630_ec_refresh_bat_info(struct yoga_c630_psy *ecbat)
+{
+	bool current_unit;
+
+	guard(mutex)(&ecbat->lock);
+
+	current_unit = ecbat->unit_mA;
+
+	yoga_c630_psy_update_bat_info(ecbat);
+
+	if (current_unit != ecbat->unit_mA) {
+		power_supply_unregister(ecbat->bat_psy);
+		yoga_c630_psy_register_bat_psy(ecbat);
+	}
+}
+
+static int yoga_c630_psy_notify(struct notifier_block *nb,
+				unsigned long action, void *data)
+{
+	struct yoga_c630_psy *ecbat = container_of(nb, struct yoga_c630_psy, nb);
+
+	switch (action) {
+	case LENOVO_EC_EVENT_BAT_INFO:
+		yoga_c630_ec_refresh_bat_info(ecbat);
+		break;
+	case LENOVO_EC_EVENT_BAT_ADPT_STATUS:
+		power_supply_changed(ecbat->adp_psy);
+		fallthrough;
+	case LENOVO_EC_EVENT_BAT_STATUS:
+		power_supply_changed(ecbat->bat_psy);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static int yoga_c630_psy_probe(struct auxiliary_device *adev,
+				   const struct auxiliary_device_id *id)
+{
+	struct yoga_c630_ec *ec = adev->dev.platform_data;
+	struct power_supply_config adp_cfg = {};
+	struct device *dev = &adev->dev;
+	struct yoga_c630_psy *ecbat;
+	int ret;
+
+	ecbat = devm_kzalloc(&adev->dev, sizeof(*ecbat), GFP_KERNEL);
+	if (!ecbat)
+		return -ENOMEM;
+
+	ecbat->ec = ec;
+	ecbat->dev = dev;
+	mutex_init(&ecbat->lock);
+	ecbat->fwnode = adev->dev.parent->fwnode;
+	ecbat->nb.notifier_call = yoga_c630_psy_notify;
+
+	auxiliary_set_drvdata(adev, ecbat);
+
+	adp_cfg.drv_data = ecbat;
+	adp_cfg.fwnode = ecbat->fwnode;
+	adp_cfg.supplied_to = (char **)&yoga_c630_psy_bat_psy_desc_mA.name;
+	adp_cfg.num_supplicants = 1;
+	ecbat->adp_psy = devm_power_supply_register_no_ws(dev, &yoga_c630_psy_adpt_psy_desc, &adp_cfg);
+	if (IS_ERR(ecbat->adp_psy)) {
+		dev_err(dev, "failed to register AC adapter supply\n");
+		return PTR_ERR(ecbat->adp_psy);
+	}
+
+	scoped_guard(mutex, &ecbat->lock) {
+		ret = yoga_c630_psy_update_bat_info(ecbat);
+		if (ret)
+			goto err_unreg_bat;
+
+		ret = yoga_c630_psy_register_bat_psy(ecbat);
+		if (ret)
+			goto err_unreg_bat;
+	}
+
+	ret = yoga_c630_ec_register_notify(ecbat->ec, &ecbat->nb);
+	if (ret)
+		goto err_unreg_bat;
+
+	return 0;
+
+err_unreg_bat:
+	power_supply_unregister(ecbat->bat_psy);
+	return ret;
+}
+
+static void yoga_c630_psy_remove(struct auxiliary_device *adev)
+{
+	struct yoga_c630_psy *ecbat = auxiliary_get_drvdata(adev);
+
+	yoga_c630_ec_unregister_notify(ecbat->ec, &ecbat->nb);
+	power_supply_unregister(ecbat->bat_psy);
+}
+
+static const struct auxiliary_device_id yoga_c630_psy_id_table[] = {
+	{ .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_PSY, },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, yoga_c630_psy_id_table);
+
+static struct auxiliary_driver yoga_c630_psy_driver = {
+	.name = YOGA_C630_DEV_PSY,
+	.id_table = yoga_c630_psy_id_table,
+	.probe = yoga_c630_psy_probe,
+	.remove = yoga_c630_psy_remove,
+};
+
+module_auxiliary_driver(yoga_c630_psy_driver);
+
+MODULE_DESCRIPTION("Lenovo Yoga C630 psy");
+MODULE_LICENSE("GPL");

-- 
2.39.2

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