[v3,2/4] mfd: max77620: add documentation for backup battery charging

Message ID 20190212064353.7451-3-markz@nvidia.com
State New
Headers show
Series
  • Add max77620 charging & low battery support
Related show

Commit Message

Mark Zhang Feb. 12, 2019, 6:43 a.m.
Adding documentation for 3 new backup battery charging dts
properties:
- maxim,charging-current-microamp
- maxim,charging-voltage-microvolt
- maxim,output-resister-ohms

Signed-off-by: Mark Zhang <markz@nvidia.com>
---
 .../devicetree/bindings/mfd/max77620.txt      | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Rob Herring Feb. 18, 2019, 6:06 p.m. | #1
On Tue, Feb 12, 2019 at 12:44 AM Mark Zhang <markz@nvidia.com> wrote:
>
> Adding documentation for 3 new backup battery charging dts
> properties:
> - maxim,charging-current-microamp
> - maxim,charging-voltage-microvolt
> - maxim,output-resister-ohms

What's the difference between the 77620 and 77650 as there's patches
on the list for the 77650 too. The properties are similar, but seems
to be main vs. backup battery charger. We should have common
properties for this.

> Signed-off-by: Mark Zhang <markz@nvidia.com>
> ---
>  .../devicetree/bindings/mfd/max77620.txt      | 20 +++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
> index 9c16d51cc15b..88825eaf2567 100644
> --- a/Documentation/devicetree/bindings/mfd/max77620.txt
> +++ b/Documentation/devicetree/bindings/mfd/max77620.txt
> @@ -122,6 +122,26 @@ For DT binding details of different sub modules like GPIO, pincontrol,
>  regulator, power, please refer respective device-tree binding document
>  under their respective sub-system directories.
>
> +Backup Battery:
> +==============
> +This sub-node configure charging backup battery of the device. Device has
> +support of charging the backup battery. The subnode name is "backup-battery".
> +The property for backup-battery child nodes as:
> +Presence of this child node will enable the backup battery charging.
> +
> +Optional properties:
> +       -maxim,charging-current-microamp: Charging current setting.
> +                       The device supports 50/100/200/400/600/800uA.
> +                       If this property is unavailable then it will
> +                       charge with 50uA.
> +       -maxim,charging-voltage-microvolt: Charging Voltage Limit Setting.
> +                       Device supports 2500000/3000000/3300000/350000uV.
> +                       Default will be set to 2500mV. The voltage will be roundoff
> +                       to nearest lower side if other than above is configured.
> +       -maxim,output-resister-ohms: Output resistor on Ohm.
> +                       Device supports 100/1000/3000/6000 Ohms.
> +                       Default will be set to 1000 Ohm.
> +
>  Example:
>  --------
>  #include <dt-bindings/mfd/max77620.h>
> --
> 2.19.2
>
Mark Zhang Feb. 19, 2019, 2:07 a.m. | #2
On 2/19/2019 2:06 AM, Rob Herring wrote:
> On Tue, Feb 12, 2019 at 12:44 AM Mark Zhang <markz@nvidia.com> wrote:
>>
>> Adding documentation for 3 new backup battery charging dts
>> properties:
>> - maxim,charging-current-microamp
>> - maxim,charging-voltage-microvolt
>> - maxim,output-resister-ohms
> 
> What's the difference between the 77620 and 77650 as there's patches
> on the list for the 77650 too. The properties are similar, but seems
> to be main vs. backup battery charger. We should have common
> properties for this.

Rob, it's different. The RTC in max77620 is supplied from a backup
battery and consumes 2.0uA (IBBATT) when no other power sources are
available. So unlike max77620 battery charging, which provides features
like:

static enum power_supply_property max77650_charger_properties[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_CHARGE_TYPE
};

For backup battery charging in max77620, what we can do is just setting
those 3 parameters. We don't know whether it's charging, whether the
backup battery is online, the percentage of the charging progress, and
etc. That's why I mentioned before that it's not appropriate to create
it as a power supply driver.

Mark

> 
>> Signed-off-by: Mark Zhang <markz@nvidia.com>
>> ---
>>  .../devicetree/bindings/mfd/max77620.txt      | 20 +++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
>> index 9c16d51cc15b..88825eaf2567 100644
>> --- a/Documentation/devicetree/bindings/mfd/max77620.txt
>> +++ b/Documentation/devicetree/bindings/mfd/max77620.txt
>> @@ -122,6 +122,26 @@ For DT binding details of different sub modules like GPIO, pincontrol,
>>  regulator, power, please refer respective device-tree binding document
>>  under their respective sub-system directories.
>>
>> +Backup Battery:
>> +==============
>> +This sub-node configure charging backup battery of the device. Device has
>> +support of charging the backup battery. The subnode name is "backup-battery".
>> +The property for backup-battery child nodes as:
>> +Presence of this child node will enable the backup battery charging.
>> +
>> +Optional properties:
>> +       -maxim,charging-current-microamp: Charging current setting.
>> +                       The device supports 50/100/200/400/600/800uA.
>> +                       If this property is unavailable then it will
>> +                       charge with 50uA.
>> +       -maxim,charging-voltage-microvolt: Charging Voltage Limit Setting.
>> +                       Device supports 2500000/3000000/3300000/350000uV.
>> +                       Default will be set to 2500mV. The voltage will be roundoff
>> +                       to nearest lower side if other than above is configured.
>> +       -maxim,output-resister-ohms: Output resistor on Ohm.
>> +                       Device supports 100/1000/3000/6000 Ohms.
>> +                       Default will be set to 1000 Ohm.
>> +
>>  Example:
>>  --------
>>  #include <dt-bindings/mfd/max77620.h>
>> --
>> 2.19.2
>>
Mark Zhang Feb. 19, 2019, 2:09 a.m. | #3
On 2/19/2019 10:07 AM, Mark Zhang wrote:
> On 2/19/2019 2:06 AM, Rob Herring wrote:
>> On Tue, Feb 12, 2019 at 12:44 AM Mark Zhang <markz@nvidia.com> wrote:
>>>
>>> Adding documentation for 3 new backup battery charging dts
>>> properties:
>>> - maxim,charging-current-microamp
>>> - maxim,charging-voltage-microvolt
>>> - maxim,output-resister-ohms
>>
>> What's the difference between the 77620 and 77650 as there's patches
>> on the list for the 77650 too. The properties are similar, but seems
>> to be main vs. backup battery charger. We should have common
>> properties for this.
> 
> Rob, it's different. The RTC in max77620 is supplied from a backup
> battery and consumes 2.0uA (IBBATT) when no other power sources are
> available. So unlike max77620 battery charging, which provides features

Oops... s/unlike max77620/unlike max77650.

Mark

> like:
> 
> static enum power_supply_property max77650_charger_properties[] = {
> 	POWER_SUPPLY_PROP_STATUS,
> 	POWER_SUPPLY_PROP_ONLINE,
> 	POWER_SUPPLY_PROP_CHARGE_TYPE
> };
> 
> For backup battery charging in max77620, what we can do is just setting
> those 3 parameters. We don't know whether it's charging, whether the
> backup battery is online, the percentage of the charging progress, and
> etc. That's why I mentioned before that it's not appropriate to create
> it as a power supply driver.
> 
> Mark
> 
>>
>>> Signed-off-by: Mark Zhang <markz@nvidia.com>
>>> ---
>>>  .../devicetree/bindings/mfd/max77620.txt      | 20 +++++++++++++++++++
>>>  1 file changed, 20 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
>>> index 9c16d51cc15b..88825eaf2567 100644
>>> --- a/Documentation/devicetree/bindings/mfd/max77620.txt
>>> +++ b/Documentation/devicetree/bindings/mfd/max77620.txt
>>> @@ -122,6 +122,26 @@ For DT binding details of different sub modules like GPIO, pincontrol,
>>>  regulator, power, please refer respective device-tree binding document
>>>  under their respective sub-system directories.
>>>
>>> +Backup Battery:
>>> +==============
>>> +This sub-node configure charging backup battery of the device. Device has
>>> +support of charging the backup battery. The subnode name is "backup-battery".
>>> +The property for backup-battery child nodes as:
>>> +Presence of this child node will enable the backup battery charging.
>>> +
>>> +Optional properties:
>>> +       -maxim,charging-current-microamp: Charging current setting.
>>> +                       The device supports 50/100/200/400/600/800uA.
>>> +                       If this property is unavailable then it will
>>> +                       charge with 50uA.
>>> +       -maxim,charging-voltage-microvolt: Charging Voltage Limit Setting.
>>> +                       Device supports 2500000/3000000/3300000/350000uV.
>>> +                       Default will be set to 2500mV. The voltage will be roundoff
>>> +                       to nearest lower side if other than above is configured.
>>> +       -maxim,output-resister-ohms: Output resistor on Ohm.
>>> +                       Device supports 100/1000/3000/6000 Ohms.
>>> +                       Default will be set to 1000 Ohm.
>>> +
>>>  Example:
>>>  --------
>>>  #include <dt-bindings/mfd/max77620.h>
>>> --
>>> 2.19.2
>>>

Patch

diff --git a/Documentation/devicetree/bindings/mfd/max77620.txt b/Documentation/devicetree/bindings/mfd/max77620.txt
index 9c16d51cc15b..88825eaf2567 100644
--- a/Documentation/devicetree/bindings/mfd/max77620.txt
+++ b/Documentation/devicetree/bindings/mfd/max77620.txt
@@ -122,6 +122,26 @@  For DT binding details of different sub modules like GPIO, pincontrol,
 regulator, power, please refer respective device-tree binding document
 under their respective sub-system directories.
 
+Backup Battery:
+==============
+This sub-node configure charging backup battery of the device. Device has
+support of charging the backup battery. The subnode name is "backup-battery".
+The property for backup-battery child nodes as:
+Presence of this child node will enable the backup battery charging.
+
+Optional properties:
+	-maxim,charging-current-microamp: Charging current setting.
+			The device supports 50/100/200/400/600/800uA.
+			If this property is unavailable then it will
+			charge with 50uA.
+	-maxim,charging-voltage-microvolt: Charging Voltage Limit Setting.
+			Device supports 2500000/3000000/3300000/350000uV.
+			Default will be set to 2500mV. The voltage will be roundoff
+			to nearest lower side if other than above is configured.
+	-maxim,output-resister-ohms: Output resistor on Ohm.
+			Device supports 100/1000/3000/6000 Ohms.
+			Default will be set to 1000 Ohm.
+
 Example:
 --------
 #include <dt-bindings/mfd/max77620.h>