// SPDX-License-Identifier: GPL-2.0 // // max17040_battery.c // fuel-gauge systems for lithium-ion (Li+) batteries // // Copyright (C) 2009 Samsung Electronics // Minkyu Kang #include #include #include #include #include #include #include #include #include #include #include #include #include #define MAX17040_VCELL 0x02 #define MAX17040_SOC 0x04 #define MAX17040_MODE 0x06 #define MAX17040_VER 0x08 #define MAX17040_CONFIG 0x0C #define MAX17040_STATUS 0x1A #define MAX17040_CMD 0xFE #define MAX17040_DELAY 1000 #define MAX17040_BATTERY_FULL 95 #define MAX17040_RCOMP_DEFAULT 0x9700 #define MAX17040_ATHD_MASK 0x3f #define MAX17040_ALSC_MASK 0x40 #define MAX17040_ATHD_DEFAULT_POWER_UP 4 #define MAX17040_STATUS_HD_MASK 0x1000 #define MAX17040_STATUS_SC_MASK 0x2000 #define MAX17040_CFG_RCOMP_MASK 0xff00 enum chip_id { ID_MAX17040, ID_MAX17041, ID_MAX17043, ID_MAX17044, ID_MAX17048, ID_MAX17049, ID_MAX17058, ID_MAX17059, }; /* values that differ by chip_id */ struct chip_data { u16 reset_val; u16 vcell_shift; u16 vcell_mul; u16 vcell_div; u8 has_low_soc_alert; u8 rcomp_bytes; u8 has_soc_alert; }; static struct chip_data max17040_family[] = { [ID_MAX17040] = { .reset_val = 0x0054, .vcell_shift = 4, .vcell_mul = 1250, .vcell_div = 1, .has_low_soc_alert = 0, .rcomp_bytes = 2, .has_soc_alert = 0, }, [ID_MAX17041] = { .reset_val = 0x0054, .vcell_shift = 4, .vcell_mul = 2500, .vcell_div = 1, .has_low_soc_alert = 0, .rcomp_bytes = 2, .has_soc_alert = 0, }, [ID_MAX17043] = { .reset_val = 0x0054, .vcell_shift = 4, .vcell_mul = 1250, .vcell_div = 1, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 0, }, [ID_MAX17044] = { .reset_val = 0x0054, .vcell_shift = 4, .vcell_mul = 2500, .vcell_div = 1, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 0, }, [ID_MAX17048] = { .reset_val = 0x5400, .vcell_shift = 0, .vcell_mul = 625, .vcell_div = 8, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 1, }, [ID_MAX17049] = { .reset_val = 0x5400, .vcell_shift = 0, .vcell_mul = 625, .vcell_div = 4, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 1, }, [ID_MAX17058] = { .reset_val = 0x5400, .vcell_shift = 0, .vcell_mul = 625, .vcell_div = 8, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 0, }, [ID_MAX17059] = { .reset_val = 0x5400, .vcell_shift = 0, .vcell_mul = 625, .vcell_div = 4, .has_low_soc_alert = 1, .rcomp_bytes = 1, .has_soc_alert = 0, }, }; struct max17040_chip { struct i2c_client *client; struct regmap *regmap; struct delayed_work work; struct power_supply *battery; struct max17040_platform_data *pdata; struct chip_data data; /* battery capacity */ int soc; /* State Of Charge */ int status; /* Low alert threshold from 32% to 1% of the State of Charge */ u32 low_soc_alert; /* some devices return twice the capacity */ bool quirk_double_soc; /* higher 8 bits for 17043+, 16 bits for 17040,41 */ u16 rcomp; }; static int max17040_reset(struct max17040_chip *chip) { return regmap_write(chip->regmap, MAX17040_CMD, chip->data.reset_val); } static int max17040_set_low_soc_alert(struct max17040_chip *chip, u32 level) { level = 32 - level * (chip->quirk_double_soc ? 2 : 1); return regmap_update_bits(chip->regmap, MAX17040_CONFIG, MAX17040_ATHD_MASK, level); } static int max17040_set_soc_alert(struct max17040_chip *chip, bool enable) { return regmap_update_bits(chip->regmap, MAX17040_CONFIG, MAX17040_ALSC_MASK, enable ? MAX17040_ALSC_MASK : 0); } static int max17040_set_rcomp(struct max17040_chip *chip, u16 rcomp) { u16 mask = chip->data.rcomp_bytes == 2 ? 0xffff : MAX17040_CFG_RCOMP_MASK; return regmap_update_bits(chip->regmap, MAX17040_CONFIG, mask, rcomp); } static int max17040_raw_vcell_to_uvolts(struct max17040_chip *chip, u16 vcell) { struct chip_data *d = &chip->data; return (vcell >> d->vcell_shift) * d->vcell_mul / d->vcell_div; } static int max17040_get_vcell(struct max17040_chip *chip) { u32 vcell; regmap_read(chip->regmap, MAX17040_VCELL, &vcell); return max17040_raw_vcell_to_uvolts(chip, vcell); } static int max17040_get_soc(struct max17040_chip *chip) { u32 soc; regmap_read(chip->regmap, MAX17040_SOC, &soc); return soc >> (chip->quirk_double_soc ? 9 : 8); } static int max17040_get_version(struct max17040_chip *chip) { int ret; u32 version; ret = regmap_read(chip->regmap, MAX17040_VER, &version); return ret ? ret : version; } static int max17040_get_online(struct max17040_chip *chip) { return chip->pdata && chip->pdata->battery_online ? chip->pdata->battery_online() : 1; } static int max17040_get_status(struct max17040_chip *chip) { if (!chip->pdata || !chip->pdata->charger_online || !chip->pdata->charger_enable) return POWER_SUPPLY_STATUS_UNKNOWN; if (max17040_get_soc(chip) > MAX17040_BATTERY_FULL) return POWER_SUPPLY_STATUS_FULL; if (chip->pdata->charger_online()) if (chip->pdata->charger_enable()) return POWER_SUPPLY_STATUS_CHARGING; else return POWER_SUPPLY_STATUS_NOT_CHARGING; else return POWER_SUPPLY_STATUS_DISCHARGING; } static int max17040_get_of_data(struct max17040_chip *chip) { struct device *dev = &chip->client->dev; struct chip_data *data = &max17040_family[ (uintptr_t) of_device_get_match_data(dev)]; int rcomp_len; u8 rcomp[2]; chip->quirk_double_soc = device_property_read_bool(dev, "maxim,double-soc"); chip->low_soc_alert = MAX17040_ATHD_DEFAULT_POWER_UP; device_property_read_u32(dev, "maxim,alert-low-soc-level", &chip->low_soc_alert); if (chip->low_soc_alert <= 0 || chip->low_soc_alert > (chip->quirk_double_soc ? 16 : 32)) { dev_err(dev, "maxim,alert-low-soc-level out of bounds\n"); return -EINVAL; } rcomp_len = device_property_count_u8(dev, "maxim,rcomp"); chip->rcomp = MAX17040_RCOMP_DEFAULT; if (rcomp_len == data->rcomp_bytes) { if (!device_property_read_u8_array(dev, "maxim,rcomp", rcomp, rcomp_len)) chip->rcomp = rcomp_len == 2 ? rcomp[0] << 8 | rcomp[1] : rcomp[0] << 8; } else if (rcomp_len > 0) { dev_err(dev, "maxim,rcomp has incorrect length\n"); return -EINVAL; } return 0; } static void max17040_check_changes(struct max17040_chip *chip) { chip->soc = max17040_get_soc(chip); chip->status = max17040_get_status(chip); } static void max17040_queue_work(struct max17040_chip *chip) { queue_delayed_work(system_power_efficient_wq, &chip->work, MAX17040_DELAY); } static void max17040_stop_work(void *data) { struct max17040_chip *chip = data; cancel_delayed_work_sync(&chip->work); } static void max17040_work(struct work_struct *work) { struct max17040_chip *chip; int last_soc, last_status; chip = container_of(work, struct max17040_chip, work.work); /* store SOC and status to check changes */ last_soc = chip->soc; last_status = chip->status; max17040_check_changes(chip); /* check changes and send uevent */ if (last_soc != chip->soc || last_status != chip->status) power_supply_changed(chip->battery); max17040_queue_work(chip); } /* Returns true if alert cause was SOC change, not low SOC */ static bool max17040_handle_soc_alert(struct max17040_chip *chip) { bool ret = true; u32 data; regmap_read(chip->regmap, MAX17040_STATUS, &data); if (data & MAX17040_STATUS_HD_MASK) { // this alert was caused by low soc ret = false; } if (data & MAX17040_STATUS_SC_MASK) { // soc change bit -- deassert to mark as handled regmap_write(chip->regmap, MAX17040_STATUS, data & ~MAX17040_STATUS_SC_MASK); } return ret; } static irqreturn_t max17040_thread_handler(int id, void *dev) { struct max17040_chip *chip = dev; if (!(chip->data.has_soc_alert && max17040_handle_soc_alert(chip))) dev_warn(&chip->client->dev, "IRQ: Alert battery low level\n"); /* read registers */ max17040_check_changes(chip); /* send uevent */ power_supply_changed(chip->battery); /* reset alert bit */ max17040_set_low_soc_alert(chip, chip->low_soc_alert); return IRQ_HANDLED; } static int max17040_enable_alert_irq(struct max17040_chip *chip) { struct i2c_client *client = chip->client; unsigned int flags; int ret; flags = IRQF_TRIGGER_FALLING | IRQF_ONESHOT; ret = devm_request_threaded_irq(&client->dev, client->irq, NULL, max17040_thread_handler, flags, chip->battery->desc->name, chip); return ret; } static int max17040_prop_writeable(struct power_supply *psy, enum power_supply_property psp) { switch (psp) { case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: return 1; default: return 0; } } static int max17040_set_property(struct power_supply *psy, enum power_supply_property psp, const union power_supply_propval *val) { struct max17040_chip *chip = power_supply_get_drvdata(psy); int ret; switch (psp) { case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: /* alert threshold can be programmed from 1% up to 16/32% */ if ((val->intval < 1) || (val->intval > (chip->quirk_double_soc ? 16 : 32))) { ret = -EINVAL; break; } ret = max17040_set_low_soc_alert(chip, val->intval); chip->low_soc_alert = val->intval; break; default: ret = -EINVAL; } return ret; } static int max17040_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { struct max17040_chip *chip = power_supply_get_drvdata(psy); switch (psp) { case POWER_SUPPLY_PROP_STATUS: val->intval = max17040_get_status(chip); break; case POWER_SUPPLY_PROP_ONLINE: val->intval = max17040_get_online(chip); break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: val->intval = max17040_get_vcell(chip); break; case POWER_SUPPLY_PROP_CAPACITY: val->intval = max17040_get_soc(chip); break; case POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN: val->intval = chip->low_soc_alert; break; default: return -EINVAL; } return 0; } static const struct regmap_config max17040_regmap = { .reg_bits = 8, .reg_stride = 2, .val_bits = 16, .val_format_endian = REGMAP_ENDIAN_BIG, }; static enum power_supply_property max17040_battery_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_ONLINE, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_CAPACITY, POWER_SUPPLY_PROP_CAPACITY_ALERT_MIN, }; static const struct power_supply_desc max17040_battery_desc = { .name = "battery", .type = POWER_SUPPLY_TYPE_BATTERY, .get_property = max17040_get_property, .set_property = max17040_set_property, .property_is_writeable = max17040_prop_writeable, .properties = max17040_battery_props, .num_properties = ARRAY_SIZE(max17040_battery_props), }; static int max17040_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct power_supply_config psy_cfg = {}; struct max17040_chip *chip; enum chip_id chip_id; bool enable_irq = false; int ret; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) return -EIO; chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; chip->client = client; chip->regmap = devm_regmap_init_i2c(client, &max17040_regmap); chip->pdata = client->dev.platform_data; chip_id = (enum chip_id) id->driver_data; if (client->dev.of_node) { ret = max17040_get_of_data(chip); if (ret) return ret; chip_id = (uintptr_t)of_device_get_match_data(&client->dev); } chip->data = max17040_family[chip_id]; i2c_set_clientdata(client, chip); psy_cfg.drv_data = chip; chip->battery = devm_power_supply_register(&client->dev, &max17040_battery_desc, &psy_cfg); if (IS_ERR(chip->battery)) { dev_err(&client->dev, "failed: power supply register\n"); return PTR_ERR(chip->battery); } ret = max17040_get_version(chip); if (ret < 0) return ret; dev_dbg(&chip->client->dev, "MAX17040 Fuel-Gauge Ver 0x%x\n", ret); if (chip_id == ID_MAX17040 || chip_id == ID_MAX17041) max17040_reset(chip); max17040_set_rcomp(chip, chip->rcomp); /* check interrupt */ if (client->irq && chip->data.has_low_soc_alert) { ret = max17040_set_low_soc_alert(chip, chip->low_soc_alert); if (ret) { dev_err(&client->dev, "Failed to set low SOC alert: err %d\n", ret); return ret; } enable_irq = true; } if (client->irq && chip->data.has_soc_alert) { ret = max17040_set_soc_alert(chip, 1); if (ret) { dev_err(&client->dev, "Failed to set SOC alert: err %d\n", ret); return ret; } enable_irq = true; } else { /* soc alerts negate the need for polling */ INIT_DEFERRABLE_WORK(&chip->work, max17040_work); ret = devm_add_action(&client->dev, max17040_stop_work, chip); if (ret) return ret; max17040_queue_work(chip); } if (enable_irq) { ret = max17040_enable_alert_irq(chip); if (ret) { client->irq = 0; dev_warn(&client->dev, "Failed to get IRQ err %d\n", ret); } } return 0; } #ifdef CONFIG_PM_SLEEP static int max17040_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct max17040_chip *chip = i2c_get_clientdata(client); if (client->irq && chip->data.has_soc_alert) // disable soc alert to prevent wakeup max17040_set_soc_alert(chip, 0); else cancel_delayed_work(&chip->work); if (client->irq && device_may_wakeup(dev)) enable_irq_wake(client->irq); return 0; } static int max17040_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct max17040_chip *chip = i2c_get_clientdata(client); if (client->irq && device_may_wakeup(dev)) disable_irq_wake(client->irq); if (client->irq && chip->data.has_soc_alert) max17040_set_soc_alert(chip, 1); else max17040_queue_work(chip); return 0; } static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume); #define MAX17040_PM_OPS (&max17040_pm_ops) #else #define MAX17040_PM_OPS NULL #endif /* CONFIG_PM_SLEEP */ static const struct i2c_device_id max17040_id[] = { { "max17040", ID_MAX17040 }, { "max17041", ID_MAX17041 }, { "max17043", ID_MAX17043 }, { "max77836-battery", ID_MAX17043 }, { "max17044", ID_MAX17044 }, { "max17048", ID_MAX17048 }, { "max17049", ID_MAX17049 }, { "max17058", ID_MAX17058 }, { "max17059", ID_MAX17059 }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(i2c, max17040_id); static const struct of_device_id max17040_of_match[] = { { .compatible = "maxim,max17040", .data = (void *) ID_MAX17040 }, { .compatible = "maxim,max17041", .data = (void *) ID_MAX17041 }, { .compatible = "maxim,max17043", .data = (void *) ID_MAX17043 }, { .compatible = "maxim,max77836-battery", .data = (void *) ID_MAX17043 }, { .compatible = "maxim,max17044", .data = (void *) ID_MAX17044 }, { .compatible = "maxim,max17048", .data = (void *) ID_MAX17048 }, { .compatible = "maxim,max17049", .data = (void *) ID_MAX17049 }, { .compatible = "maxim,max17058", .data = (void *) ID_MAX17058 }, { .compatible = "maxim,max17059", .data = (void *) ID_MAX17059 }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, max17040_of_match); static struct i2c_driver max17040_i2c_driver = { .driver = { .name = "max17040", .of_match_table = max17040_of_match, .pm = MAX17040_PM_OPS, }, .probe = max17040_probe, .id_table = max17040_id, }; module_i2c_driver(max17040_i2c_driver); MODULE_AUTHOR("Minkyu Kang "); MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); MODULE_LICENSE("GPL");