// 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 #include #include #include #include #include #include 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; psy_cfg.no_wakeup_source = true; bat->regmap = dev_get_regmap(pdev->dev.parent, "KB930"); if (!bat->regmap) return -EINVAL; bat->psy = devm_power_supply_register(&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 void a500_battery_remove(struct platform_device *pdev) { struct a500_battery *bat = dev_get_drvdata(&pdev->dev); cancel_delayed_work_sync(&bat->poll_work); } 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 "); MODULE_ALIAS("platform:acer-a500-iconia-battery"); MODULE_LICENSE("GPL");