Re: [PATCH v12 2/4] dt-bindings: power: Convert battery.txt to battery.yaml

From: Rob Herring
Date: Fri May 29 2020 - 18:16:21 EST


On Thu, May 28, 2020 at 05:53:48PM -0500, Ricardo Rivera-Matos wrote:
> From: Dan Murphy <dmurphy@xxxxxx>
>
> Convert the battery.txt file to yaml and fix up the examples.
>
> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> ---
> .../bindings/power/supply/battery.txt | 82 +---------
> .../bindings/power/supply/battery.yaml | 143 ++++++++++++++++++
> 2 files changed, 144 insertions(+), 81 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/power/supply/battery.yaml
>
> diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt
> index 3049cf88bdcf..b9a81621ce59 100644
> --- a/Documentation/devicetree/bindings/power/supply/battery.txt
> +++ b/Documentation/devicetree/bindings/power/supply/battery.txt
> @@ -1,81 +1 @@
> -Battery Characteristics
> -
> -The devicetree battery node provides static battery characteristics.
> -In smart batteries, these are typically stored in non-volatile memory
> -on a fuel gauge chip. The battery node should be used where there is
> -no appropriate non-volatile memory, or it is unprogrammed/incorrect.
> -
> -Upstream dts files should not include battery nodes, unless the battery
> -represented cannot easily be replaced in the system by one of a
> -different type. This prevents unpredictable, potentially harmful,
> -behavior should a replacement that changes the battery type occur
> -without a corresponding update to the dtb.
> -
> -Required Properties:
> - - compatible: Must be "simple-battery"
> -
> -Optional Properties:
> - - voltage-min-design-microvolt: drained battery voltage
> - - voltage-max-design-microvolt: fully charged battery voltage
> - - energy-full-design-microwatt-hours: battery design energy
> - - charge-full-design-microamp-hours: battery design capacity
> - - precharge-current-microamp: current for pre-charge phase
> - - charge-term-current-microamp: current for charge termination phase
> - - constant-charge-current-max-microamp: maximum constant input current
> - - constant-charge-voltage-max-microvolt: maximum constant input voltage
> - - factory-internal-resistance-micro-ohms: battery factory internal resistance
> - - ocv-capacity-table-0: An array providing the open circuit voltage (OCV)
> - of the battery and corresponding battery capacity percent, which is used
> - to look up battery capacity according to current OCV value. And the open
> - circuit voltage unit is microvolt.
> - - ocv-capacity-table-1: Same as ocv-capacity-table-0
> - ......
> - - ocv-capacity-table-n: Same as ocv-capacity-table-0
> - - ocv-capacity-celsius: 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.
> - - resistance-temp-table: An array providing the temperature in degree Celsius
> - and corresponding battery internal resistance percent, which is used to look
> - up the resistance percent according to current temperature to get a accurate
> - batterty internal resistance in different temperatures.
> -
> -Battery properties are named, where possible, for the corresponding
> -elements in enum power_supply_property, defined in
> -https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h
> -
> -Batteries must be referenced by chargers and/or fuel-gauges
> -using a phandle. The phandle's property should be named
> -"monitored-battery".
> -
> -Example:
> -
> - bat: battery {
> - compatible = "simple-battery";
> - voltage-min-design-microvolt = <3200000>;
> - voltage-max-design-microvolt = <4200000>;
> - energy-full-design-microwatt-hours = <5290000>;
> - charge-full-design-microamp-hours = <1430000>;
> - precharge-current-microamp = <256000>;
> - charge-term-current-microamp = <128000>;
> - constant-charge-current-max-microamp = <900000>;
> - constant-charge-voltage-max-microvolt = <4200000>;
> - factory-internal-resistance-micro-ohms = <250000>;
> - ocv-capacity-celsius = <(-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>, ...;
> - resistance-temp-table = <20 100>, <10 90>, <0 80>, <(-10) 60>;
> - };
> -
> - charger: charger@11 {
> - ....
> - monitored-battery = <&bat>;
> - ...
> - };
> -
> - fuel_gauge: fuel-gauge@22 {
> - ....
> - monitored-battery = <&bat>;
> - ...
> - };
> +The contents of this file has been moved to battery.yaml
> diff --git a/Documentation/devicetree/bindings/power/supply/battery.yaml b/Documentation/devicetree/bindings/power/supply/battery.yaml
> new file mode 100644
> index 000000000000..f0b544a22219
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/supply/battery.yaml
> @@ -0,0 +1,143 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/supply/battery.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Battery Characteristics
> +
> +maintainers:
> + - Sebastian Reichel <sre@xxxxxxxxxx>
> +
> +description: |
> + The devicetree battery node provides static battery characteristics.
> + In smart batteries, these are typically stored in non-volatile memory
> + on a fuel gauge chip. The battery node should be used where there is
> + no appropriate non-volatile memory, or it is unprogrammed/incorrect.
> +
> + Upstream dts files should not include battery nodes, unless the battery
> + represented cannot easily be replaced in the system by one of a
> + different type. This prevents unpredictable, potentially harmful,
> + behavior should a replacement that changes the battery type occur
> + without a corresponding update to the dtb.
> +
> + Battery properties are named, where possible, for the corresponding elements
> + in enum power_supply_property, defined in include/linux/power_supply.h
> +
> + Batteries must be referenced by chargers and/or fuel-gauges using a phandle.
> + The phandle's property should be named "monitored-battery".
> +
> +properties:
> + compatible:
> + const: simple-battery

I suspect we'll need a battery.yaml and simple-battery.yaml schema if
these properties are used for other batteries. Not sure really, so fine
for now.

> +
> + voltage-min-design-microvolt:
> + $ref: /schemas/types.yaml#/definitions/uint32

Don't need types on many of these as standard units have a type already.

> + description: drained battery voltage
> +
> + voltage-max-design-microvolt:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: fully charged battery voltage
> +
> + energy-full-design-microwatt-hours:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: battery design energy
> +
> + charge-full-design-microamp-hours:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: battery design capacity
> +
> + precharge-current-microamp:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: current for pre-charge phase
> +
> + charge-term-current-microamp:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: current for charge termination phase
> +
> + constant-charge-current-max-microamp:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: maximum constant input current
> +
> + constant-charge-voltage-max-microvolt:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: maximum constant input voltage
> +
> + factory-internal-resistance-micro-ohms:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description: battery factory internal resistance
> +
> + ocv-capacity-table-0:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: |
> + An array providing the open circuit voltage (OCV)
> + of the battery and corresponding battery capacity percent, which is used
> + to look up battery capacity according to current OCV value. And the open
> + circuit voltage unit is microvolt.
> +
> + ocv-capacity-table-1:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: Same as ocv-capacity-table-0
> +
> + ocv-capacity-table-n:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: Same as ocv-capacity-table-0

Make this a pattern under patternProperties: '^ocv-capacity-table-[0-9]$'

Is 10 enough or maybe you need more.

maxItems: 100 ?? I asssume 1% granularity would be enough for everyone?
items:
items:
- description: open circuit voltage (OCV) in microvolts
- description: battery capacity percent
maximum: 100

> +
> + ocv-capacity-celsius:
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> + description: |
> + 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.
> +
> + resistance-temp-table:
> + $ref: /schemas/types.yaml#/definitions/uint32-matrix
> + description: |
> + An array providing the temperature in degree Celsius
> + and corresponding battery internal resistance percent, which is used to
> + look up the resistance percent according to current temperature to get an
> + accurate batterty internal resistance in different temperatures.

Similar definition needed here.

> +
> + monitored-battery:
> + $ref: /schemas/types.yaml#/definitions/phandle
> + description: phandle to the battery node being monitored

As this is the battery node, this property doesn't belong here.

> +
> +required:
> + - compatible
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + power {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + battery:battery {
> + compatible = "simple-battery";
> + voltage-min-design-microvolt = <3200000>;
> + voltage-max-design-microvolt = <4200000>;
> + energy-full-design-microwatt-hours = <5290000>;
> + charge-full-design-microamp-hours = <1430000>;
> + precharge-current-microamp = <256000>;
> + charge-term-current-microamp = <128000>;
> + constant-charge-current-max-microamp = <900000>;
> + constant-charge-voltage-max-microvolt = <4200000>;
> + factory-internal-resistance-micro-ohms = <250000>;
> + ocv-capacity-celsius = <(-10) 0 10>;
> + ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 90>;
> + ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 90>;
> + resistance-temp-table = <20 100>, <10 90>, <0 80>, <(-10) 60>;
> + };
> +
> + charger:charger@11 {

Drop unused labels.

> + reg = <0x11>;
> + monitored-battery = <&battery>;
> + };
> +
> + fuel_gauge:fuel-gauge@22 {
> + reg = <0x22>;
> + monitored-battery = <&battery>;
> + };
> + };
> --
> 2.26.2
>