#define POWER_SUPPLY_OCV_TEMP_MAX 20
-/*
+/**
+ * struct power_supply_battery_info - information about batteries
+ * @technology: from the POWER_SUPPLY_TECHNOLOGY_* enum
+ * @energy_full_design_uwh: energy content when fully charged in microwatt
+ * hours
+ * @charge_full_design_uah: charge content when fully charged in microampere
+ * hours
+ * @voltage_min_design_uv: minimum voltage across the poles when the battery
+ * is at minimum voltage level in microvolts. If the voltage drops below this
+ * level the battery will need precharging when using CC/CV charging.
+ * @voltage_max_design_uv: voltage across the poles when the battery is fully
+ * charged in microvolts. This is the "nominal voltage" i.e. the voltage
+ * printed on the label of the battery.
+ * @tricklecharge_current_ua: the tricklecharge current used when trickle
+ * charging the battery in microamperes. This is the charging phase when the
+ * battery is completely empty and we need to carefully trickle in some
+ * charge until we reach the precharging voltage.
+ * @precharge_current_ua: current to use in the precharge phase in microamperes,
+ * the precharge rate is limited by limiting the current to this value.
+ * @precharge_voltage_max_uv: the maximum voltage allowed when precharging in
+ * microvolts. When we pass this voltage we will nominally switch over to the
+ * CC (constant current) charging phase defined by constant_charge_current_ua
+ * and constant_charge_voltage_max_uv.
+ * @charge_term_current_ua: when the current in the CV (constant voltage)
+ * charging phase drops below this value in microamperes the charging will
+ * terminate completely and not restart until the voltage over the battery
+ * poles reach charge_restart_voltage_uv unless we use maintenance charging.
+ * @charge_restart_voltage_uv: when the battery has been fully charged by
+ * CC/CV charging and charging has been disabled, and the voltage subsequently
+ * drops below this value in microvolts, the charging will be restarted
+ * (typically using CV charging).
+ * @overvoltage_limit_uv: If the voltage exceeds the nominal voltage
+ * voltage_max_design_uv and we reach this voltage level, all charging must
+ * stop and emergency procedures take place, such as shutting down the system
+ * in some cases.
+ * @constant_charge_current_max_ua: current in microamperes to use in the CC
+ * (constant current) charging phase. The charging rate is limited
+ * by this current. This is the main charging phase and as the current is
+ * constant into the battery the voltage slowly ascends to
+ * constant_charge_voltage_max_uv.
+ * @constant_charge_voltage_max_uv: voltage in microvolts signifying the end of
+ * the CC (constant current) charging phase and the beginning of the CV
+ * (constant voltage) charging phase.
+ * @factory_internal_resistance_uohm: the internal resistance of the battery
+ * at fabrication time, expressed in microohms. This resistance will vary
+ * depending on the lifetime and charge of the battery, so this is just a
+ * nominal ballpark figure.
+ * @ocv_temp: array indicating the open circuit voltage (OCV) capacity
+ * temperature indices. This is an array of temperatures in degrees Celsius
+ * indicating which capacity table to use for a certain temperature, since
+ * the capacity for reasons of chemistry will be different at different
+ * temperatures. Determining capacity is a multivariate problem and the
+ * temperature is the first variable we determine.
+ * @temp_ambient_alert_min: the battery will go outside of operating conditions
+ * when the ambient temperature goes below this temperature in degrees
+ * Celsius.
+ * @temp_ambient_alert_max: the battery will go outside of operating conditions
+ * when the ambient temperature goes above this temperature in degrees
+ * Celsius.
+ * @temp_alert_min: the battery should issue an alert if the internal
+ * temperature goes below this temperature in degrees Celsius.
+ * @temp_alert_max: the battery should issue an alert if the internal
+ * temperature goes above this temperature in degrees Celsius.
+ * @temp_min: the battery will go outside of operating conditions when
+ * the internal temperature goes below this temperature in degrees Celsius.
+ * Normally this means the system should shut down.
+ * @temp_max: the battery will go outside of operating conditions when
+ * the internal temperature goes above this temperature in degrees Celsius.
+ * Normally this means the system should shut down.
+ * @ocv_table: for each entry in ocv_temp there is a corresponding entry in
+ * ocv_table and a size for each entry in ocv_table_size. These arrays
+ * determine the capacity in percent in relation to the voltage in microvolts
+ * at the indexed temperature.
+ * @ocv_table_size: for each entry in ocv_temp this array is giving the size of
+ * each entry in the array of capacity arrays in ocv_table.
+ * @resist_table: this is a table that correlates a battery temperature to the
+ * expected internal resistance at this temperature. The resistance is given
+ * as a percentage of factory_internal_resistance_uohm. Knowing the
+ * resistance of the battery is usually necessary for calculating the open
+ * circuit voltage (OCV) that is then used with the ocv_table to calculate
+ * the capacity of the battery. The resist_table must be ordered descending
+ * by temperature: highest temperature with lowest resistance first, lowest
+ * temperature with highest resistance last.
+ * @resist_table_size: the number of items in the resist_table.
+ *
* 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.
+ *
+ * The charging parameters here assume a CC/CV charging scheme. This method
+ * is most common with Lithium Ion batteries (other methods are possible) and
+ * looks as follows:
+ *
+ * ^ Battery voltage
+ * | --- overvoltage_limit_uv
+ * |
+ * | ...................................................
+ * | .. constant_charge_voltage_max_uv
+ * | ..
+ * | .
+ * | .
+ * | .
+ * | .
+ * | .
+ * | .. precharge_voltage_max_uv
+ * | ..
+ * |. (trickle charging)
+ * +------------------------------------------------------------------> time
+ *
+ * ^ Current into the battery
+ * |
+ * | ............. constant_charge_current_max_ua
+ * | . .
+ * | . .
+ * | . .
+ * | . .
+ * | . ..
+ * | . ....
+ * | . .....
+ * | ... precharge_current_ua ....... charge_term_current_ua
+ * | . .
+ * | . .
+ * |.... tricklecharge_current_ua .
+ * | .
+ * +-----------------------------------------------------------------> time
+ *
+ * These diagrams are synchronized on time and the voltage and current
+ * follow each other.
+ *
+ * With CC/CV charging commence over time like this for an empty battery:
+ *
+ * 1. When the battery is completely empty it may need to be charged with
+ * an especially small current so that electrons just "trickle in",
+ * this is the tricklecharge_current_ua.
+ *
+ * 2. Next a small initial pre-charge current (precharge_current_ua)
+ * is applied if the voltage is below precharge_voltage_max_uv until we
+ * reach precharge_voltage_max_uv. CAUTION: in some texts this is referred
+ * to as "trickle charging" but the use in the Linux kernel is different
+ * see below!
+ *
+ * 3. Then the main charging current is applied, which is called the constant
+ * current (CC) phase. A current regulator is set up to allow
+ * constant_charge_current_max_ua of current to flow into the battery.
+ * The chemical reaction in the battery will make the voltage go up as
+ * charge goes into the battery. This current is applied until we reach
+ * the constant_charge_voltage_max_uv voltage.
+ *
+ * 4. At this voltage we switch over to the constant voltage (CV) phase. This
+ * means we allow current to go into the battery, but we keep the voltage
+ * fixed. This current will continue to charge the battery while keeping
+ * the voltage the same. A chemical reaction in the battery goes on
+ * storing energy without affecting the voltage. Over time the current
+ * will slowly drop and when we reach charge_term_current_ua we will
+ * end the constant voltage phase.
+ *
+ * After this the battery is fully charged, and if we do not support maintenance
+ * charging, the charging will not restart until power dissipation makes the
+ * voltage fall so that we reach charge_restart_voltage_uv and at this point
+ * we restart charging at the appropriate phase, usually this will be inside
+ * the CV phase.
+ *
+ * If we support maintenance charging the voltage is however kept high after
+ * the CV phase with a very low current. This is meant to let the same charge
+ * go in for usage while the charger is still connected, mainly for
+ * dissipation for the power consuming entity while connected to the
+ * charger.
+ *
+ * All charging MUST terminate if the overvoltage_limit_uv is ever reached.
+ * Overcharging Lithium Ion cells can be DANGEROUS and lead to fire or
+ * explosions.
+ *
+ * The power supply class itself doesn't use this struct as of now.
*/
struct power_supply_battery_info {
- unsigned int technology; /* from the enum above */
- int energy_full_design_uwh; /* microWatt-hours */
- int charge_full_design_uah; /* microAmp-hours */
- int voltage_min_design_uv; /* microVolts */
- int voltage_max_design_uv; /* microVolts */
- int tricklecharge_current_ua; /* microAmps */
- int precharge_current_ua; /* microAmps */
- int precharge_voltage_max_uv; /* microVolts */
- int charge_term_current_ua; /* microAmps */
- int charge_restart_voltage_uv; /* microVolts */
- int overvoltage_limit_uv; /* microVolts */
- int constant_charge_current_max_ua; /* microAmps */
- int constant_charge_voltage_max_uv; /* microVolts */
- int factory_internal_resistance_uohm; /* microOhms */
- int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];/* celsius */
- int temp_ambient_alert_min; /* celsius */
- int temp_ambient_alert_max; /* celsius */
- int temp_alert_min; /* celsius */
- int temp_alert_max; /* celsius */
- int temp_min; /* celsius */
- int temp_max; /* celsius */
+ unsigned int technology;
+ int energy_full_design_uwh;
+ int charge_full_design_uah;
+ int voltage_min_design_uv;
+ int voltage_max_design_uv;
+ int tricklecharge_current_ua;
+ int precharge_current_ua;
+ int precharge_voltage_max_uv;
+ int charge_term_current_ua;
+ int charge_restart_voltage_uv;
+ int overvoltage_limit_uv;
+ int constant_charge_current_max_ua;
+ int constant_charge_voltage_max_uv;
+ int factory_internal_resistance_uohm;
+ int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];
+ int temp_ambient_alert_min;
+ int temp_ambient_alert_max;
+ int temp_alert_min;
+ int temp_alert_max;
+ int temp_min;
+ int temp_max;
struct power_supply_battery_ocv_table *ocv_table[POWER_SUPPLY_OCV_TEMP_MAX];
int ocv_table_size[POWER_SUPPLY_OCV_TEMP_MAX];
struct power_supply_resistance_temp_table *resist_table;
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