From c08b1f45d7d193b3e6dcbbf30d403cb49b667b8c Mon Sep 17 00:00:00 2001 From: Liam Breck Date: Wed, 7 Jun 2017 11:37:51 -0700 Subject: [PATCH] power: supply: core: Add power_supply_battery_info and API power_supply_get_battery_info() reads battery data from devicetree. struct power_supply_battery_info provides battery data to drivers. Its fields correspond to elements in enum power_supply_property. Drivers may surface battery data in sysfs via corresponding POWER_SUPPLY_PROP_* fields. Signed-off-by: Matt Ranostay Signed-off-by: Liam Breck Signed-off-by: Sebastian Reichel --- Documentation/power/power_supply_class.txt | 12 +++++++ drivers/power/supply/power_supply_core.c | 57 ++++++++++++++++++++++++++++++ include/linux/power_supply.h | 22 ++++++++++++ 3 files changed, 91 insertions(+) diff --git a/Documentation/power/power_supply_class.txt b/Documentation/power/power_supply_class.txt index 0c72588..01f0075 100644 --- a/Documentation/power/power_supply_class.txt +++ b/Documentation/power/power_supply_class.txt @@ -174,6 +174,18 @@ issued by external power supply will notify supplicants via external_power_changed callback. +Devicetree battery characteristics +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Drivers should call power_supply_get_battery_info() to obtain battery +characteristics from a devicetree battery node, defined in +Documentation/devicetree/bindings/power/supply/battery.txt. This is +implemented in drivers/power/supply/bq27xxx_battery.c. + +Properties in struct power_supply_battery_info and their counterparts in the +battery node have names corresponding to elements in enum power_supply_property, +for naming consistency between sysfs attributes and battery node properties. + + QA ~~ Q: Where is POWER_SUPPLY_PROP_XYZ attribute? diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 0c09144..a4303ed 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include "power_supply.h" @@ -519,6 +520,62 @@ struct power_supply *devm_power_supply_get_by_phandle(struct device *dev, EXPORT_SYMBOL_GPL(devm_power_supply_get_by_phandle); #endif /* CONFIG_OF */ +int power_supply_get_battery_info(struct power_supply *psy, + struct power_supply_battery_info *info) +{ + struct device_node *battery_np; + const char *value; + int err; + + info->energy_full_design_uwh = -EINVAL; + info->charge_full_design_uah = -EINVAL; + info->voltage_min_design_uv = -EINVAL; + info->precharge_current_ua = -EINVAL; + info->charge_term_current_ua = -EINVAL; + info->constant_charge_current_max_ua = -EINVAL; + info->constant_charge_voltage_max_uv = -EINVAL; + + if (!psy->of_node) { + dev_warn(&psy->dev, "%s currently only supports devicetree\n", + __func__); + return -ENXIO; + } + + battery_np = of_parse_phandle(psy->of_node, "monitored-battery", 0); + if (!battery_np) + return -ENODEV; + + err = of_property_read_string(battery_np, "compatible", &value); + if (err) + return err; + + if (strcmp("simple-battery", value)) + return -ENODEV; + + /* The property and field names below must correspond to elements + * in enum power_supply_property. For reasoning, see + * Documentation/power/power_supply_class.txt. + */ + + of_property_read_u32(battery_np, "energy-full-design-microwatt-hours", + &info->energy_full_design_uwh); + of_property_read_u32(battery_np, "charge-full-design-microamp-hours", + &info->charge_full_design_uah); + of_property_read_u32(battery_np, "voltage-min-design-microvolt", + &info->voltage_min_design_uv); + of_property_read_u32(battery_np, "precharge-current-microamp", + &info->precharge_current_ua); + of_property_read_u32(battery_np, "charge-term-current-microamp", + &info->charge_term_current_ua); + of_property_read_u32(battery_np, "constant_charge_current_max_microamp", + &info->constant_charge_current_max_ua); + of_property_read_u32(battery_np, "constant_charge_voltage_max_microvolt", + &info->constant_charge_voltage_max_uv); + + return 0; +} +EXPORT_SYMBOL_GPL(power_supply_get_battery_info); + int power_supply_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 4bd3405..34345d7 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -289,6 +289,25 @@ struct power_supply_info { int use_for_apm; }; +/* + * This is the recommended struct to manage static battery parameters, + * populated by power_supply_get_battery_info(). Most platform drivers should + * use these for consistency. + * Its field names must correspond to elements in enum power_supply_property. + * The default field value is -EINVAL. + * Power supply class itself doesn't use this. + */ + +struct power_supply_battery_info { + int energy_full_design_uwh; /* microWatt-hours */ + int charge_full_design_uah; /* microAmp-hours */ + int voltage_min_design_uv; /* microVolts */ + int precharge_current_ua; /* microAmps */ + int charge_term_current_ua; /* microAmps */ + int constant_charge_current_max_ua; /* microAmps */ + int constant_charge_voltage_max_uv; /* microVolts */ +}; + extern struct atomic_notifier_head power_supply_notifier; extern int power_supply_reg_notifier(struct notifier_block *nb); extern void power_supply_unreg_notifier(struct notifier_block *nb); @@ -307,6 +326,9 @@ static inline struct power_supply * devm_power_supply_get_by_phandle(struct device *dev, const char *property) { return NULL; } #endif /* CONFIG_OF */ + +extern int power_supply_get_battery_info(struct power_supply *psy, + struct power_supply_battery_info *info); extern void power_supply_changed(struct power_supply *psy); extern int power_supply_am_i_supplied(struct power_supply *psy); extern int power_supply_set_battery_charged(struct power_supply *psy); -- 2.7.4