From 65dbad713d5d6a8581921804ae3f5eb4a9bf032e Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Mon, 9 Dec 2019 11:56:22 +0800 Subject: [PATCH] power: supply: core: Add battery internal resistance temperature table support Since the battery internal resistance can be changed with the temperature changes, thus add a resistance temperature table support to look up the accurate battery internal resistance in a certain temperature. Signed-off-by: Baolin Wang Signed-off-by: Baolin Wang Signed-off-by: Sebastian Reichel --- drivers/power/supply/power_supply_core.c | 67 +++++++++++++++++++++++- include/linux/power_supply.h | 10 ++++ 2 files changed, 76 insertions(+), 1 deletion(-) diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 5c36c430ce8b..1a9a9fae73d3 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -565,9 +565,11 @@ EXPORT_SYMBOL_GPL(devm_power_supply_get_by_phandle); int power_supply_get_battery_info(struct power_supply *psy, struct power_supply_battery_info *info) { + struct power_supply_resistance_temp_table *resist_table; struct device_node *battery_np; const char *value; int err, len, index; + const __be32 *list; info->energy_full_design_uwh = -EINVAL; info->charge_full_design_uah = -EINVAL; @@ -578,6 +580,7 @@ int power_supply_get_battery_info(struct power_supply *psy, info->constant_charge_current_max_ua = -EINVAL; info->constant_charge_voltage_max_uv = -EINVAL; info->factory_internal_resistance_uohm = -EINVAL; + info->resist_table = NULL; for (index = 0; index < POWER_SUPPLY_OCV_TEMP_MAX; index++) { info->ocv_table[index] = NULL; @@ -644,7 +647,6 @@ int power_supply_get_battery_info(struct power_supply *psy, for (index = 0; index < len; index++) { struct power_supply_battery_ocv_table *table; char *propname; - const __be32 *list; int i, tab_len, size; propname = kasprintf(GFP_KERNEL, "ocv-capacity-table-%d", index); @@ -677,6 +679,26 @@ int power_supply_get_battery_info(struct power_supply *psy, } } + list = of_get_property(battery_np, "resistance-temp-table", &len); + if (!list || !len) + goto out_put_node; + + info->resist_table_size = len / (2 * sizeof(__be32)); + resist_table = info->resist_table = devm_kcalloc(&psy->dev, + info->resist_table_size, + sizeof(*resist_table), + GFP_KERNEL); + if (!info->resist_table) { + power_supply_put_battery_info(psy, info); + err = -ENOMEM; + goto out_put_node; + } + + for (index = 0; index < info->resist_table_size; index++) { + resist_table[index].temp = be32_to_cpu(*list++); + resist_table[index].resistance = be32_to_cpu(*list++); + } + out_put_node: of_node_put(battery_np); return err; @@ -692,9 +714,52 @@ void power_supply_put_battery_info(struct power_supply *psy, if (info->ocv_table[i]) devm_kfree(&psy->dev, info->ocv_table[i]); } + + if (info->resist_table) + devm_kfree(&psy->dev, info->resist_table); } EXPORT_SYMBOL_GPL(power_supply_put_battery_info); +/** + * power_supply_temp2resist_simple() - find the battery internal resistance + * percent + * @table: Pointer to battery resistance temperature table + * @table_len: The table length + * @ocv: Current temperature + * + * This helper function is used to look up battery internal resistance percent + * according to current temperature value from the resistance temperature table, + * and the table must be ordered descending. Then the actual battery internal + * resistance = the ideal battery internal resistance * percent / 100. + * + * Return: the battery internal resistance percent + */ +int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table, + int table_len, int temp) +{ + int i, resist; + + for (i = 0; i < table_len; i++) + if (temp > table[i].temp) + break; + + if (i > 0 && i < table_len) { + int tmp; + + tmp = (table[i - 1].resistance - table[i].resistance) * + (temp - table[i].temp); + tmp /= table[i - 1].temp - table[i].temp; + resist = tmp + table[i].resistance; + } else if (i == 0) { + resist = table[0].resistance; + } else { + resist = table[table_len - 1].resistance; + } + + return resist; +} +EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple); + /** * power_supply_ocv2cap_simple() - find the battery capacity * @table: Pointer to battery OCV lookup table diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 28413f737e7d..dcd5a71e6c67 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -325,6 +325,11 @@ struct power_supply_battery_ocv_table { int capacity; /* percent */ }; +struct power_supply_resistance_temp_table { + int temp; /* celsius */ + int resistance; /* internal resistance percent */ +}; + #define POWER_SUPPLY_OCV_TEMP_MAX 20 /* @@ -349,6 +354,8 @@ struct power_supply_battery_info { int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX];/* celsius */ 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; + int resist_table_size; }; extern struct atomic_notifier_head power_supply_notifier; @@ -381,6 +388,9 @@ power_supply_find_ocv2cap_table(struct power_supply_battery_info *info, int temp, int *table_len); extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp); +extern int +power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table, + int table_len, int temp); 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_input_current_limit_from_supplier(