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

[kgunda@codeaurora.org]

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On 2018-06-21 00:35, Rob Herring wrote: 

> 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@codeaurora.org>
>> ---
>> .../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'.
> Thanks for reviewing it!. I added this because the step value for PM8941(WLED3) and PMI8998(WLED4)

> are different. for WLED3 the step is 5mA and for WLED4 the step is 2.5mA. To mantain

> the backward compatibility i have added the new property with out modifying the existing

> one (qcom,current-limit).
> 
>> - 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.

> Yes. It is same. WLED3 has the OVP values 27V, 29V, 32V, 35V, where as

> WELD4 has 18.1V, 19.6V, 29.6V, 31.1V.
> 
>> +    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 [].

> It is u32. I will correct dts syntax in next series as <0x00 0x01 0x02 0x03>,

> which is mentioned in the example.

+
+- 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. 
Ok. Will modify as per your suggestion in the next series.

+    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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