Re: [PATCH V3 3/7] backlight: qcom-wled: Add new properties for PMI8998

From: Rob Herring
Date: Wed Jun 20 2018 - 15:05:11 EST


On Tue, Jun 19, 2018 at 04:43:38PM +0530, Kiran Gunda wrote:
> Update the bindings with the new properties used for
> PMI8998.
>
> Signed-off-by: Kiran Gunda <kgunda@xxxxxxxxxxxxxx>
> ---
> .../bindings/leds/backlight/qcom-wled.txt | 84 ++++++++++++++++++++--
> 1 file changed, 77 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> index 14f28f2..503ce87 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
> @@ -48,11 +48,15 @@ platforms. The PMIC is connected to the host processor via SPMI bus.
> - qcom,current-limit
> Usage: optional
> Value type: <u32>
> - Definition: mA; per-string current limit
> - value: For pm8941: from 0 to 25 with 5 mA step
> - Default 20 mA.
> - For pmi8998: from 0 to 30 with 5 mA step
> - Default 25 mA.
> + Definition: mA; per-string current limit; value from 0 to 25 with
> + 1 mA step. Default 20 mA.
> + This property is supported only for pm8941.
> +
> +- qcom,current-limit-microamp
> + Usage: optional
> + Value type: <u32>
> + Definition: uA; per-string current limit; value from 0 to 30000 with
> + 2500 uA step. Default 25000 uA.

This doesn't really seem worth adding just to add '-microamp'.


> - qcom,current-boost-limit
> Usage: optional
> @@ -79,12 +83,61 @@ platforms. The PMIC is connected to the host processor via SPMI bus.
> 27, 29, 32, 35. default: 29V
> This property is supported only for PM8941.
>
> +- qcom,ovp-millivolt

Is this the same as qcom,ovp? If so, same comment.

> + Usage: optional
> + Value type: <u32>
> + Definition: mV; Over-voltage protection limit;
> + For pmi8998: one of 18100, 19600, 29600, 31100
> + Default: 29600 mV
> + If this property is not specified for PM8941, it
> + falls back to "qcom,ovp" property.
> +
> - qcom,num-strings
> Usage: optional
> Value type: <u32>
> Definition: #; number of led strings attached;
> - value from 1 to 3. default: 2
> - This property is supported only for PM8941.
> + value: For PM8941 from 1 to 3. default: 2
> + For PMI8998 from 1 to 4. default: 4
> +
> +- interrupts
> + Usage: optional
> + Value type: <prop encoded array>
> + Definition: Interrupts associated with WLED. This should be
> + "short" and "ovp" interrupts. Interrupts can be
> + specified as per the encoding listed under
> + Documentation/devicetree/bindings/spmi/
> + qcom,spmi-pmic-arb.txt.
> +
> +- interrupt-names
> + Usage: optional
> + Value type: <string>
> + Definition: Interrupt names associated with the interrupts.
> + Must be "short" and "ovp". The short circuit detection
> + is not supported for PM8941.
> +
> +- qcom,enabled-strings
> + Usage: optional
> + Value tyoe: <u32 array>
> + Definition: Array of the WLED strings numbered from 0 to 3. Each
> + string of leds are operated individually. Specify the
> + list of strings used by the device. Any combination of
> + led strings can be used.
> + for pm8941: Default values are [00 01].
> + for pmi8998: Default values are [00 01 02 03].

u32 or u8 because dts syntax for 8-bit array is [].

> +
> +- qcom,external-pfet
> + Usage: optional
> + Value type: <bool>
> + Definition: Specify if external PFET control for short circuit
> + protection is used. This property is supported only
> + for PMI8998.
> +
> +- qcom,auto-string-detection
> + Usage: optional
> + Value type: <bool>
> + Definition: Enables auto-detection of the WLED string configuration.
> + This feature is not supported for PM8941.
> +
>
> Example:
>
> @@ -99,4 +152,21 @@ pm8941-wled@d800 {
> qcom,switching-freq = <1600>;
> qcom,ovp = <29>;
> qcom,num-strings = <2>;
> + qcom,enabled-strings = <0x00 0x01>;
> +};
> +
> +pmi8998-wled@d800 {

led-controller {

And needs a unit-address.

> + compatible = "qcom,pmi8998-wled";
> + reg = <0xd800 0xd900>;
> + label = "backlight";
> +
> + interrupts = <3 0xd8 2 IRQ_TYPE_EDGE_RISING>,
> + <3 0xd8 1 IRQ_TYPE_EDGE_RISING>;
> + interrupt-names = "short", "ovp";
> + qcom,current-limit-microamp = <25000>;
> + qcom,current-boost-limit = <805>;
> + qcom,switching-freq = <1600>;
> + qcom,ovp-millivolt = <29600>;
> + qcom,num-strings = <4>;
> + qcom,enabled-strings = <0x00 0x01 0x02 0x03>;
> };
> --
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