On 2018-09-04 00:25, Bjorn Andersson wrote:
On Wed 15 Aug 22:23 PDT 2018, kgunda@codeaurora.org wrote:
On 2018-08-07 10:53, Bjorn Andersson wrote:
On Mon 09 Jul 03:22 PDT 2018, Kiran Gunda wrote:
diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt
[..]
- qcom,num-strings Usage: optional Value type: <u32> Definition: #; number of led strings attached;
value from 1 to 3. default: 2This property is supported only for PM8941.
value: For PM8941 from 1 to 3.For PMI8998 from 1 to 4.[..]
+- 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 thelist of strings used by the device. Any combination ofled strings can be used.[..]
Example:
@@ -99,4 +146,5 @@ pm8941-wled@d800 { qcom,switching-freq = <1600>; qcom,ovp = <29>; qcom,num-strings = <2>;
- qcom,enabled-strings = <0x00 0x01>;
Nit. I would assume that specifying qcom,num-strings = <2> implies that the first 2 strings are used, so one would not also specify qcom,enabled-strings.
Thanks Bjorn for reviewing the series !
"qcom,enabled-strings" need be specified along with the "qcom,num-strings". Because the enabled-strings can be <0, 2> or <0, 3 > also. The driver picks the string configuration from the enabled-strings array and enable only those current-sinks.
The original binding described qcom,num-strings to mean "the first N strings", requiring qcom,enabled-strings now would break backwards compatibility with this binding.
In the case that qcom,enabled-strings is specified we can easily derive num-strings from the listed entires. So I would suggest that you look for enabled-strings and if not found fall back to checking for num-strings.
Regards, Bjorn
Sorry for the late reply. Actually the "qcom,enabled-strings" is initialized with the strings 0, 1, 2, 3 in the driver. Even though this property is missing the first N strings will be still configured with out any issue, based on the "qcom,num-strings".