drivers/power/supply/acer_a500_battery.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Battery driver for Acer Iconia Tab A500.
  *
  * Copyright 2020 GRATE-driver project.
  *
  * Based on downstream driver from Acer Inc.
  * Based on NVIDIA Gas Gauge driver for SBS Compliant Batteries.
  *
  * Copyright (c) 2010, NVIDIA Corporation.
  */

 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/regmap.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>

 enum {
 	REG_CAPACITY,
 	REG_VOLTAGE,
 	REG_CURRENT,
 	REG_DESIGN_CAPACITY,
 	REG_TEMPERATURE,
 };

 #define EC_DATA(_reg, _psp) {			\
 	.psp = POWER_SUPPLY_PROP_ ## _psp,	\
 	.reg = _reg,				\
 }

 static const struct battery_register {
 	enum power_supply_property psp;
 	unsigned int reg;
 } ec_data[] = {
 	[REG_CAPACITY]		= EC_DATA(0x00, CAPACITY),
 	[REG_VOLTAGE]		= EC_DATA(0x01, VOLTAGE_NOW),
 	[REG_CURRENT]		= EC_DATA(0x03, CURRENT_NOW),
 	[REG_DESIGN_CAPACITY]	= EC_DATA(0x08, CHARGE_FULL_DESIGN),
 	[REG_TEMPERATURE]	= EC_DATA(0x0a, TEMP),
 };

 static const enum power_supply_property a500_battery_properties[] = {
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 };

 struct a500_battery {
 	struct delayed_work poll_work;
 	struct power_supply *psy;
 	struct regmap *regmap;
 	unsigned int capacity;
 };

 static bool a500_battery_update_capacity(struct a500_battery *bat)
 {
 	unsigned int capacity;
 	int err;

 	err = regmap_read(bat->regmap, ec_data[REG_CAPACITY].reg, &capacity);
 	if (err)
 		return false;

 	/* capacity can be >100% even if max value is 100% */
 	capacity = min(capacity, 100u);

 	if (bat->capacity != capacity) {
 		bat->capacity = capacity;
 		return true;
 	}

 	return false;
 }

 static int a500_battery_get_status(struct a500_battery *bat)
 {
 	if (bat->capacity < 100) {
 		if (power_supply_am_i_supplied(bat->psy))
 			return POWER_SUPPLY_STATUS_CHARGING;
 		else
 			return POWER_SUPPLY_STATUS_DISCHARGING;
 	}

 	return POWER_SUPPLY_STATUS_FULL;
 }

 static void a500_battery_unit_adjustment(struct device *dev,
 					 enum power_supply_property psp,
 					 union power_supply_propval *val)
 {
 	const unsigned int base_unit_conversion = 1000;
 	const unsigned int temp_kelvin_to_celsius = 2731;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		val->intval *= base_unit_conversion;
 		break;

 	case POWER_SUPPLY_PROP_TEMP:
 		val->intval -= temp_kelvin_to_celsius;
 		break;

 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = !!val->intval;
 		break;

 	default:
 		dev_dbg(dev,
 			"%s: no need for unit conversion %d\n", __func__, psp);
 	}
 }

 static int a500_battery_get_ec_data_index(struct device *dev,
 					  enum power_supply_property psp)
 {
 	unsigned int i;

 	/*
 	 * DESIGN_CAPACITY register always returns a non-zero value if
 	 * battery is connected and zero if disconnected, hence we'll use
 	 * it for judging the battery presence.
 	 */
 	if (psp == POWER_SUPPLY_PROP_PRESENT)
 		psp = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;

 	for (i = 0; i < ARRAY_SIZE(ec_data); i++)
 		if (psp == ec_data[i].psp)
 			return i;

 	dev_dbg(dev, "%s: invalid property %u\n", __func__, psp);

 	return -EINVAL;
 }

 static int a500_battery_get_property(struct power_supply *psy,
 				     enum power_supply_property psp,
 				     union power_supply_propval *val)
 {
 	struct a500_battery *bat = power_supply_get_drvdata(psy);
 	struct device *dev = psy->dev.parent;
 	int ret = 0;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		val->intval = a500_battery_get_status(bat);
 		break;

 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
 		break;

 	case POWER_SUPPLY_PROP_CAPACITY:
 		a500_battery_update_capacity(bat);
 		val->intval = bat->capacity;
 		break;

 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 	case POWER_SUPPLY_PROP_PRESENT:
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = a500_battery_get_ec_data_index(dev, psp);
 		if (ret < 0)
 			break;

 		ret = regmap_read(bat->regmap, ec_data[ret].reg, &val->intval);
 		break;

 	default:
 		dev_err(dev, "%s: invalid property %u\n", __func__, psp);
 		return -EINVAL;
 	}

 	if (!ret) {
 		/* convert units to match requirements of power supply class */
 		a500_battery_unit_adjustment(dev, psp, val);
 	}

 	dev_dbg(dev, "%s: property = %d, value = %x\n",
 		__func__, psp, val->intval);

 	/* return NODATA for properties if battery not presents */
 	if (ret)
 		return -ENODATA;

 	return 0;
 }

 static void a500_battery_poll_work(struct work_struct *work)
 {
 	struct a500_battery *bat;
 	bool capacity_changed;

 	bat = container_of(work, struct a500_battery, poll_work.work);
 	capacity_changed = a500_battery_update_capacity(bat);

 	if (capacity_changed)
 		power_supply_changed(bat->psy);

 	/* continuously send uevent notification */
 	schedule_delayed_work(&bat->poll_work, 30 * HZ);
 }

 static const struct power_supply_desc a500_battery_desc = {
 	.name = "ec-battery",
 	.type = POWER_SUPPLY_TYPE_BATTERY,
 	.properties = a500_battery_properties,
 	.get_property = a500_battery_get_property,
 	.num_properties = ARRAY_SIZE(a500_battery_properties),
 	.external_power_changed = power_supply_changed,
 };

 static int a500_battery_probe(struct platform_device *pdev)
 {
 	struct power_supply_config psy_cfg = {};
 	struct a500_battery *bat;

 	bat = devm_kzalloc(&pdev->dev, sizeof(*bat), GFP_KERNEL);
 	if (!bat)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, bat);

 	psy_cfg.of_node = pdev->dev.parent->of_node;
 	psy_cfg.drv_data = bat;

 	bat->regmap = dev_get_regmap(pdev->dev.parent, "KB930");
 	if (!bat->regmap)
 		return -EINVAL;

 	bat->psy = devm_power_supply_register_no_ws(&pdev->dev,
 						    &a500_battery_desc,
 						    &psy_cfg);
 	if (IS_ERR(bat->psy))
 		return dev_err_probe(&pdev->dev, PTR_ERR(bat->psy),
 				     "failed to register battery\n");

 	INIT_DELAYED_WORK(&bat->poll_work, a500_battery_poll_work);
 	schedule_delayed_work(&bat->poll_work, HZ);

 	return 0;
 }

 static int a500_battery_remove(struct platform_device *pdev)
 {
 	struct a500_battery *bat = dev_get_drvdata(&pdev->dev);

 	cancel_delayed_work_sync(&bat->poll_work);

 	return 0;
 }

 static int __maybe_unused a500_battery_suspend(struct device *dev)
 {
 	struct a500_battery *bat = dev_get_drvdata(dev);

 	cancel_delayed_work_sync(&bat->poll_work);

 	return 0;
 }

 static int __maybe_unused a500_battery_resume(struct device *dev)
 {
 	struct a500_battery *bat = dev_get_drvdata(dev);

 	schedule_delayed_work(&bat->poll_work, HZ);

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(a500_battery_pm_ops,
 			 a500_battery_suspend, a500_battery_resume);

 static struct platform_driver a500_battery_driver = {
 	.driver = {
 		.name = "acer-a500-iconia-battery",
 		.pm = &a500_battery_pm_ops,
 	},
 	.probe = a500_battery_probe,
 	.remove = a500_battery_remove,
 };
 module_platform_driver(a500_battery_driver);

 MODULE_DESCRIPTION("Battery gauge driver for Acer Iconia Tab A500");
 MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
 MODULE_ALIAS("platform:acer-a500-iconia-battery");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Battery driver for Acer Iconia Tab A500.
	*
	* Copyright 2020 GRATE-driver project.
	*
	* Based on downstream driver from Acer Inc.
	* Based on NVIDIA Gas Gauge driver for SBS Compliant Batteries.
	*
	* Copyright (c) 2010, NVIDIA Corporation.
	*/

	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/power_supply.h>
	#include <linux/regmap.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/workqueue.h>

	enum {
	REG_CAPACITY,
	REG_VOLTAGE,
	REG_CURRENT,
	REG_DESIGN_CAPACITY,
	REG_TEMPERATURE,
	};

	#define EC_DATA(_reg, _psp) { \
	.psp = POWER_SUPPLY_PROP_ ## _psp, \
	.reg = _reg, \
	}

	static const struct battery_register {
	enum power_supply_property psp;
	unsigned int reg;
	} ec_data[] = {
	[REG_CAPACITY] = EC_DATA(0x00, CAPACITY),
	[REG_VOLTAGE] = EC_DATA(0x01, VOLTAGE_NOW),
	[REG_CURRENT] = EC_DATA(0x03, CURRENT_NOW),
	[REG_DESIGN_CAPACITY] = EC_DATA(0x08, CHARGE_FULL_DESIGN),
	[REG_TEMPERATURE] = EC_DATA(0x0a, TEMP),
	};

	static const enum power_supply_property a500_battery_properties[] = {
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	};

	struct a500_battery {
	struct delayed_work poll_work;
	struct power_supply *psy;
	struct regmap *regmap;
	unsigned int capacity;
	};

	static bool a500_battery_update_capacity(struct a500_battery *bat)
	{
	unsigned int capacity;
	int err;

	err = regmap_read(bat->regmap, ec_data[REG_CAPACITY].reg, &capacity);
	if (err)
	return false;

	/* capacity can be >100% even if max value is 100% */
	capacity = min(capacity, 100u);

	if (bat->capacity != capacity) {
	bat->capacity = capacity;
	return true;
	}

	return false;
	}

	static int a500_battery_get_status(struct a500_battery *bat)
	{
	if (bat->capacity < 100) {
	if (power_supply_am_i_supplied(bat->psy))
	return POWER_SUPPLY_STATUS_CHARGING;
	else
	return POWER_SUPPLY_STATUS_DISCHARGING;
	}

	return POWER_SUPPLY_STATUS_FULL;
	}

	static void a500_battery_unit_adjustment(struct device *dev,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	const unsigned int base_unit_conversion = 1000;
	const unsigned int temp_kelvin_to_celsius = 2731;

	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	val->intval *= base_unit_conversion;
	break;

	case POWER_SUPPLY_PROP_TEMP:
	val->intval -= temp_kelvin_to_celsius;
	break;

	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = !!val->intval;
	break;

	default:
	dev_dbg(dev,
	"%s: no need for unit conversion %d\n", __func__, psp);
	}
	}

	static int a500_battery_get_ec_data_index(struct device *dev,
	enum power_supply_property psp)
	{
	unsigned int i;

	/*
	* DESIGN_CAPACITY register always returns a non-zero value if
	* battery is connected and zero if disconnected, hence we'll use
	* it for judging the battery presence.
	*/
	if (psp == POWER_SUPPLY_PROP_PRESENT)
	psp = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;

	for (i = 0; i < ARRAY_SIZE(ec_data); i++)
	if (psp == ec_data[i].psp)
	return i;

	dev_dbg(dev, "%s: invalid property %u\n", __func__, psp);

	return -EINVAL;
	}

	static int a500_battery_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct a500_battery *bat = power_supply_get_drvdata(psy);
	struct device *dev = psy->dev.parent;
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	val->intval = a500_battery_get_status(bat);
	break;

	case POWER_SUPPLY_PROP_TECHNOLOGY:
	val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
	break;

	case POWER_SUPPLY_PROP_CAPACITY:
	a500_battery_update_capacity(bat);
	val->intval = bat->capacity;
	break;

	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	case POWER_SUPPLY_PROP_PRESENT:
	case POWER_SUPPLY_PROP_TEMP:
	ret = a500_battery_get_ec_data_index(dev, psp);
	if (ret < 0)
	break;

	ret = regmap_read(bat->regmap, ec_data[ret].reg, &val->intval);
	break;

	default:
	dev_err(dev, "%s: invalid property %u\n", __func__, psp);
	return -EINVAL;
	}

	if (!ret) {
	/* convert units to match requirements of power supply class */
	a500_battery_unit_adjustment(dev, psp, val);
	}

	dev_dbg(dev, "%s: property = %d, value = %x\n",
	__func__, psp, val->intval);

	/* return NODATA for properties if battery not presents */
	if (ret)
	return -ENODATA;

	return 0;
	}

	static void a500_battery_poll_work(struct work_struct *work)
	{
	struct a500_battery *bat;
	bool capacity_changed;

	bat = container_of(work, struct a500_battery, poll_work.work);
	capacity_changed = a500_battery_update_capacity(bat);

	if (capacity_changed)
	power_supply_changed(bat->psy);

	/* continuously send uevent notification */
	schedule_delayed_work(&bat->poll_work, 30 * HZ);
	}

	static const struct power_supply_desc a500_battery_desc = {
	.name = "ec-battery",
	.type = POWER_SUPPLY_TYPE_BATTERY,
	.properties = a500_battery_properties,
	.get_property = a500_battery_get_property,
	.num_properties = ARRAY_SIZE(a500_battery_properties),
	.external_power_changed = power_supply_changed,
	};

	static int a500_battery_probe(struct platform_device *pdev)
	{
	struct power_supply_config psy_cfg = {};
	struct a500_battery *bat;

	bat = devm_kzalloc(&pdev->dev, sizeof(*bat), GFP_KERNEL);
	if (!bat)
	return -ENOMEM;

	platform_set_drvdata(pdev, bat);

	psy_cfg.of_node = pdev->dev.parent->of_node;
	psy_cfg.drv_data = bat;

	bat->regmap = dev_get_regmap(pdev->dev.parent, "KB930");
	if (!bat->regmap)
	return -EINVAL;

	bat->psy = devm_power_supply_register_no_ws(&pdev->dev,
	&a500_battery_desc,
	&psy_cfg);
	if (IS_ERR(bat->psy))
	return dev_err_probe(&pdev->dev, PTR_ERR(bat->psy),
	"failed to register battery\n");

	INIT_DELAYED_WORK(&bat->poll_work, a500_battery_poll_work);
	schedule_delayed_work(&bat->poll_work, HZ);

	return 0;
	}

	static int a500_battery_remove(struct platform_device *pdev)
	{
	struct a500_battery *bat = dev_get_drvdata(&pdev->dev);

	cancel_delayed_work_sync(&bat->poll_work);

	return 0;
	}

	static int __maybe_unused a500_battery_suspend(struct device *dev)
	{
	struct a500_battery *bat = dev_get_drvdata(dev);

	cancel_delayed_work_sync(&bat->poll_work);

	return 0;
	}

	static int __maybe_unused a500_battery_resume(struct device *dev)
	{
	struct a500_battery *bat = dev_get_drvdata(dev);

	schedule_delayed_work(&bat->poll_work, HZ);

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(a500_battery_pm_ops,
	a500_battery_suspend, a500_battery_resume);

	static struct platform_driver a500_battery_driver = {
	.driver = {
	.name = "acer-a500-iconia-battery",
	.pm = &a500_battery_pm_ops,
	},
	.probe = a500_battery_probe,
	.remove = a500_battery_remove,
	};
	module_platform_driver(a500_battery_driver);

	MODULE_DESCRIPTION("Battery gauge driver for Acer Iconia Tab A500");
	MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
	MODULE_ALIAS("platform:acer-a500-iconia-battery");
	MODULE_LICENSE("GPL");