diff mbox series

[v2,2/4] power: supply: core: Introduce properties to present the battery OCV table

Message ID b78ff03ecd251b63430f05b505e02b19e196364e.1537930252.git.baolin.wang@linaro.org (mailing list archive)
State Not Applicable, archived
Headers show
Series [v2,1/4] power: supply: core: Introduce one property to present the battery internal resistance | expand

Commit Message

(Exiting) Baolin Wang Sept. 26, 2018, 2:59 a.m. UTC
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 <sre@kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
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(-)

Comments

Linus Walleij Sept. 26, 2018, 8:02 a.m. UTC | #1
On Wed, Sep 26, 2018 at 5:00 AM Baolin Wang <baolin.wang@linaro.org> 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 <sre@kernel.org>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
> Changes from v1:
>  - New patch in v2.

To the best of my knowledge this is a very good binding and core
functionality:
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Sebastian Reichel Sept. 26, 2018, 1:51 p.m. UTC | #2
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 <sre@kernel.org>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
> 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
(Exiting) Baolin Wang Sept. 27, 2018, 1:10 a.m. UTC | #3
On 26 September 2018 at 21:51, Sebastian Reichel <sre@kernel.org> wrote:
> 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 <sre@kernel.org>
>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
>> ---
>> 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.

Yes.

>
>> +                     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.

Sure.

>
>> +             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.

Fortunately existing users did not have an OCV table. Moreover once
this patch merged, I will send patches to add
power_supply_put_battery_info() for existing users of battery info.
Sebastian Reichel Sept. 27, 2018, 6:40 a.m. UTC | #4
Hi,

On Thu, Sep 27, 2018 at 09:10:05AM +0800, Baolin Wang wrote:
> On 26 September 2018 at 21:51, Sebastian Reichel <sre@kernel.org> wrote:
> > 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.
> 
> Fortunately existing users did not have an OCV table.

Right. I was just talking about potential memory leak, if the DT
file of these boards has the OCV table defined. I don't think
that this will be a problem in real life.

> Moreover once this patch merged, I will send patches to add
> power_supply_put_battery_info() for existing users of battery
> info.

Thanks.

-- Sebastian
diff mbox series

Patch

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");
+			power_supply_put_battery_info(psy, info);
+			return -EINVAL;
+		}
+
+		tab_len = size / sizeof(*table);
+		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(