Messages in this thread | | | Subject | Re: [PATCH 1/2] dt: bindings: lp5024: Introduce the lp5024 and lp5018 RGB driver | From | Jacek Anaszewski <> | Date | Wed, 9 Jan 2019 21:12:15 +0100 |
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Hi Dan,
On 1/8/19 10:22 PM, Dan Murphy wrote: > On 1/8/19 3:16 PM, Jacek Anaszewski wrote: >> On 1/8/19 9:53 PM, Dan Murphy wrote: >>> Jacek >>> >>> On 1/8/19 2:33 PM, Jacek Anaszewski wrote: >>>> Dan, >>>> >>>> On 12/19/18 5:26 PM, Dan Murphy wrote: >>>>> Introduce the bindings for the Texas Instruments LP5024 and the LP5018 >>>>> RGB LED device driver. The LP5024/18 can control RGB LEDs individually >>>>> or as part of a control bank group. These devices have the ability >>>>> to adjust the mixing control for the RGB LEDs to obtain different colors >>>>> independent of the overall brightness of the LED grouping. >>>>> >>>>> Datasheet: >>>>> http://www.ti.com/lit/ds/symlink/lp5024.pdf >>>>> >>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com> >>>>> --- >>>>> .../devicetree/bindings/leds/leds-lp5024.txt | 63 +++++++++++++++++++ >>>>> 1 file changed, 63 insertions(+) >>>>> create mode 100644 Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/leds/leds-lp5024.txt b/Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>> new file mode 100644 >>>>> index 000000000000..9567aa6f7813 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/leds/leds-lp5024.txt >>>>> @@ -0,0 +1,63 @@ >>>>> +* Texas Instruments - LP5024/18 RGB LED driver >>>>> + >>>>> +The LM3692x is an ultra-compact, highly efficient, >>>>> +white-LED driver designed for LCD display backlighting. >>>>> + >>>>> +The main difference between the LP5024 and L5018 is the number of >>>>> +RGB LEDs they support. The LP5024 supports twenty four strings while the >>>>> +LP5018 supports eighteen strings. >>>>> + >>>>> +Required properties: >>>>> + - compatible: >>>>> + "ti,lp5018" >>>>> + "ti,lp5024" >>>>> + - reg : I2C slave address >>>>> + - #address-cells : 1 >>>>> + - #size-cells : 0 >>>>> + >>>>> +Optional properties: >>>>> + - enable-gpios : gpio pin to enable/disable the device. >>>>> + - vled-supply : LED supply >>>>> + >>>>> +Required child properties: >>>>> + - reg : Is the child node iteration. >>>>> + - led-sources : LP5024 - 0 - 7 >>>>> + LP5018 - 0 - 5 >>>>> + Declares the LED string or strings that the child node >>>>> + will control. If ti,control-bank is set then this >>>>> + property will contain multiple LED IDs. >>>>> + >>>>> +Optional child properties: >>>>> + - label : see Documentation/devicetree/bindings/leds/common.txt >>>>> + - linux,default-trigger : >>>>> + see Documentation/devicetree/bindings/leds/common.txt >>>>> + - ti,control-bank : Indicates that the LED strings declared in the >>>>> + led-sources property are grouped within a control >>>>> + bank for brightness and mixing control. >>>>> + >>>>> +Example: >>>>> + >>>>> +led-controller@28 { >>>>> + compatible = "ti,lp5024"; >>>>> + reg = <0x28>; >>>>> + #address-cells = <1>; >>>>> + #size-cells = <0>; >>>>> + >>>>> + enable-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>; >>>>> + vled-supply = <&vbatt>; >>>>> + >>>>> + led@0 { >>>>> + reg = <0>; >>>>> + led-sources = <1>; >>>>> + }; >>>>> + >>>>> + led@1 { >>>>> + reg = <1>; >>>>> + led-sources = <0 6>; >>>>> + ti,control-bank; >>>> >>>> Do you really need ti,control-bank? Doesn't led-sources array size >>>> greater than 1 mean that the node describes control bank? >>>> >>> >>> That will work too. >> >>>> Also, does it make sense to have only two LEDs in the bank? >>> >>> The array can populate all 7 LEDs in a single node. I only show 2 here as the example. >>> See the description above of the led-sources >> >> OK, I confused RGB LED modules with banks. >> >> Shouldn't we allow for defining either strings or RGB LED >> triplets somehow then? >> > > Well that is what this should be doing. If you define a single LED in LED sources then > the triplet is controlled via the associated LEDx_brightness register.
led-sources should map to iouts directly. So, for RGB LED modules I would expect:
LED0: led-sources = <0 1 2>; LED1: led-sources = <3 4 5>; LED2: led-sources = <6 7 8>; and so on.
for banks:
Bank A with iouts 0,3,6,9: led-sources<0 3 6 9>; Bank B with iouts 2,4,10: led-sources<2 4 10>; Bank C with iouts 5,8,11,14,17: led-sources<5 8 11 14 17>;
We could additionally mark banks with ti,control-bank, but I'm not sure if it would ease parsing, since you will have to validate iouts configuration anyway.
> If you have multiple LED sources defined in the led-sources then those LEDs would be grouped in the bank. > I guess I need to provide some protection or a warning if a DT defines two banks because there is only one bank control.
Does the hardware allow the IOUT to belong to an RGB LED module and to a bank in the same time?
-- Best regards, Jacek Anaszewski
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