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Diffstat (limited to 'Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt')
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diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt new file mode 100644 index 000000000000..c06863badfbd --- /dev/null +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-wled.txt @@ -0,0 +1,154 @@ +Binding for Qualcomm Technologies, Inc. WLED driver + +WLED (White Light Emitting Diode) driver is used for controlling display +backlight that is part of PMIC on Qualcomm Technologies, Inc. reference +platforms. The PMIC is connected to the host processor via SPMI bus. + +- compatible + Usage: required + Value type: <string> + Definition: should be one of: + "qcom,pm8941-wled" + "qcom,pmi8998-wled" + "qcom,pm660l-wled" + +- reg + Usage: required + Value type: <prop encoded array> + Definition: Base address of the WLED modules. + +- default-brightness + Usage: optional + Value type: <u32> + Definition: brightness value on boot, value from: 0-4095. + Default: 2048 + +- label + Usage: required + Value type: <string> + Definition: The name of the backlight device + +- qcom,cs-out + Usage: optional + Value type: <bool> + Definition: enable current sink output. + This property is supported only for PM8941. + +- qcom,cabc + Usage: optional + Value type: <bool> + Definition: enable content adaptive backlight control. + +- qcom,ext-gen + Usage: optional + Value type: <bool> + Definition: use externally generated modulator signal to dim. + This property is supported only for PM8941. + +- qcom,current-limit + Usage: optional + Value type: <u32> + 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 25 mA. + +- qcom,current-boost-limit + Usage: optional + Value type: <u32> + Definition: mA; boost current limit. + For pm8941: one of: 105, 385, 525, 805, 980, 1260, 1400, + 1680. Default: 805 mA. + For pmi8998: one of: 105, 280, 450, 620, 970, 1150, 1300, + 1500. Default: 970 mA. + +- qcom,switching-freq + Usage: optional + Value type: <u32> + Definition: kHz; switching frequency; one of: 600, 640, 685, 738, + 800, 872, 960, 1066, 1200, 1371, 1600, 1920, 2400, 3200, + 4800, 9600. + Default: for pm8941: 1600 kHz + for pmi8998: 800 kHz + +- qcom,ovp + Usage: optional + Value type: <u32> + Definition: V; Over-voltage protection limit; one of: + 27, 29, 32, 35. Default: 29V + This property is supported only for PM8941. + +- qcom,ovp-millivolt + 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: For PM8941 from 1 to 3. Default: 2 + For PMI8998 from 1 to 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. + +- 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: + +pm8941-wled@d800 { + compatible = "qcom,pm8941-wled"; + reg = <0xd800>; + label = "backlight"; + + qcom,cs-out; + qcom,current-limit = <20>; + qcom,current-boost-limit = <805>; + qcom,switching-freq = <1600>; + qcom,ovp = <29>; + qcom,num-strings = <2>; + qcom,enabled-strings = <0 1>; +}; |