Hi, On Wed, Sep 26, 2018 at 10:59:12AM +0800, Baolin Wang wrote: > Some battery driver will use the open circuit voltage (OCV) value to look > up the corresponding battery capacity percent in one certain degree Celsius. > Thus this patch provides some battery properties to present the OCV table > temperatures and OCV capacity table values. > > Suggested-by: Sebastian Reichel <[email protected]> > Signed-off-by: Baolin Wang <[email protected]> > --- > Changes from v1: > - New patch in v2. > --- > .../devicetree/bindings/power/supply/battery.txt | 14 +++++ > drivers/power/supply/power_supply_core.c | 63 > +++++++++++++++++++- > include/linux/power_supply.h | 11 ++++ > 3 files changed, 87 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt > b/Documentation/devicetree/bindings/power/supply/battery.txt > index 25b9d2e..ac2b303 100644 > --- a/Documentation/devicetree/bindings/power/supply/battery.txt > +++ b/Documentation/devicetree/bindings/power/supply/battery.txt > @@ -23,6 +23,16 @@ Optional Properties: > - constant-charge-current-max-microamp: maximum constant input current > - constant-charge-voltage-max-microvolt: maximum constant input voltage > - internal-resistance-micro-ohms: battery internal resistance > + - ocv-capacity-table-0: An array providing the battery capacity percent > + with corresponding open circuit voltage (OCV) of the battery, which > + is used to look up battery capacity according to current OCV value. > + - ocv-capacity-table-1: Same as ocv-capacity-table-0 > + ...... > + - ocv-capacity-table-n: Same as ocv-capacity-table-0 > + - ocv-capacity-table-temperatures: An array containing the temperature > + in degree Celsius, for each of the battery capacity lookup table. > + The first temperature value specifies the OCV table 0, and the second > + temperature value specifies the OCV table 1, and so on. > > Battery properties are named, where possible, for the corresponding > elements in enum power_supply_property, defined in > @@ -44,6 +54,10 @@ Example: > constant-charge-current-max-microamp = <900000>; > constant-charge-voltage-max-microvolt = <4200000>; > internal-resistance-micro-ohms = <250000>; > + ocv-capacity-table-temperatures = <(-10) 0 10>; > + ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 > 90>, ...; > + ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 > 90>, ...; > + ocv-capacity-table-2 = <4250000 100>, <4200000 95>, <4185000 > 90>, ...; > }; > > charger: charger@11 { > diff --git a/drivers/power/supply/power_supply_core.c > b/drivers/power/supply/power_supply_core.c > index 9f3452f..151ff03 100644 > --- a/drivers/power/supply/power_supply_core.c > +++ b/drivers/power/supply/power_supply_core.c > @@ -570,7 +570,7 @@ int power_supply_get_battery_info(struct power_supply > *psy, > { > struct device_node *battery_np; > const char *value; > - int err; > + int err, len, index; > > info->energy_full_design_uwh = -EINVAL; > info->charge_full_design_uah = -EINVAL; > @@ -581,6 +581,12 @@ int power_supply_get_battery_info(struct power_supply > *psy, > info->constant_charge_voltage_max_uv = -EINVAL; > info->internal_resistance_uohm = -EINVAL; > > + for (index = 0; index < POWER_SUPPLY_OCV_TEMP_MAX; index++) { > + info->ocv_table[index] = NULL; > + info->ocv_temp[index] = -EINVAL; > + info->ocv_table_size[index] = -EINVAL; > + } > + > if (!psy->of_node) { > dev_warn(&psy->dev, "%s currently only supports devicetree\n", > __func__); > @@ -620,10 +626,65 @@ int power_supply_get_battery_info(struct power_supply > *psy, > of_property_read_u32(battery_np, "internal-resistance-micro-ohms", > &info->internal_resistance_uohm); > > + len = of_property_count_u32_elems(battery_np, > + "ocv-capacity-table-temperatures"); > + if (len < 0 && len != -EINVAL) { > + return len; > + } else if (len > POWER_SUPPLY_OCV_TEMP_MAX) { > + dev_err(&psy->dev, "Too many temperature values\n"); > + return -EINVAL; > + } else if (len > 0) { > + of_property_read_u32_array(battery_np, > + "ocv-capacity-table-temperatures", > + info->ocv_temp, len); > + } > + > + 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); > + list = of_get_property(battery_np, propname, &size); > + kfree(propname); > + if (!list || !size) { > + dev_err(&psy->dev, "failed to get ocv capacity > table\n");
I think it's better to replace "ocv capacity table" with %s / propname.
> + power_supply_put_battery_info(psy, info);
> + return -EINVAL;
> + }
> +
> + tab_len = size / sizeof(*table);
I think this should be
tab_len = size / (2 * sizeof(__be32));
which decouples DT memory layout from kernel memory layout.
> + info->ocv_table_size[index] = tab_len;
> +
> + table = info->ocv_table[index] = devm_kzalloc(&psy->dev,
> + tab_len * sizeof(*table),
> + GFP_KERNEL);
> + if (!info->ocv_table[index]) {
> + power_supply_put_battery_info(psy, info);
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < tab_len; i++) {
> + table[i].ocv = be32_to_cpu(*list++);
> + table[i].capacity = be32_to_cpu(*list++);
> + }
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(power_supply_get_battery_info);
>
> +void power_supply_put_battery_info(struct power_supply *psy,
> + struct power_supply_battery_info *info)
> +{
> + int i;
> +
> + for (i = 0; i < POWER_SUPPLY_OCV_TEMP_MAX; i++)
> + kfree(info->ocv_table[i]);
> +}
> +EXPORT_SYMBOL_GPL(power_supply_put_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 019452d..b0a2768 100644
> --- a/include/linux/power_supply.h
> +++ b/include/linux/power_supply.h
> @@ -309,6 +309,12 @@ struct power_supply_info {
> int use_for_apm;
> };
>
> +struct power_supply_battery_ocv_table {
> + int ocv; /* microVolts */
> + int capacity; /* percent */
> +};
> +
> +#define POWER_SUPPLY_OCV_TEMP_MAX 20
> /*
> * This is the recommended struct to manage static battery parameters,
> * populated by power_supply_get_battery_info(). Most platform drivers should
> @@ -327,6 +333,9 @@ struct power_supply_battery_info {
> int constant_charge_current_max_ua; /* microAmps */
> int constant_charge_voltage_max_uv; /* microVolts */
> int internal_resistance_uohm; /* microOhms */
> + 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];
> };
>
> extern struct atomic_notifier_head power_supply_notifier;
> @@ -350,6 +359,8 @@ extern struct power_supply
> *devm_power_supply_get_by_phandle(
>
> extern int power_supply_get_battery_info(struct power_supply *psy,
> struct power_supply_battery_info
> *info);
> +extern void power_supply_put_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_input_current_limit_from_supplier(
Looks good to me. Technically this can result in existing users of
power_supply_get_battery_info leaking memory, if they have an OCV
table in DT.
-- Sebastian
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