diff options
Diffstat (limited to 'drivers/power/supply/max17040_battery.c')
| -rw-r--r-- | drivers/power/supply/max17040_battery.c | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/drivers/power/supply/max17040_battery.c b/drivers/power/supply/max17040_battery.c new file mode 100644 index 000000000..a9aef1e8b --- /dev/null +++ b/drivers/power/supply/max17040_battery.c @@ -0,0 +1,609 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// max17040_battery.c +// fuel-gauge systems for lithium-ion (Li+) batteries +// +// Copyright (C) 2009 Samsung Electronics +// Minkyu Kang <mk7.kang@samsung.com> + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/mutex.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/power_supply.h> +#include <linux/of_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#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 chip_data data; + + /* battery capacity */ + int soc; + /* 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 1; +} + +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); +} + +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; + + chip = container_of(work, struct max17040_chip, work.work); + + /* store SOC to check changes */ + last_soc = chip->soc; + max17040_check_changes(chip); + + /* check changes and send uevent */ + if (last_soc != chip->soc) + 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; + int ret; + + ret = devm_request_threaded_irq(&client->dev, client->irq, NULL, + max17040_thread_handler, IRQF_ONESHOT, + 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_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_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); + if (IS_ERR(chip->regmap)) + return PTR_ERR(chip->regmap); + 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 <mk7.kang@samsung.com>"); +MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); +MODULE_LICENSE("GPL"); |