From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Murphy Subject: Re: [PATCH 1/2] dt: bindings: lp5024: Introduce the lp5024 and lp5018 RGB driver Date: Tue, 8 Jan 2019 15:22:10 -0600 Message-ID: <366cbf6d-94fa-fea9-be58-07ddb09cff3a@ti.com> References: <20181219162626.12297-1-dmurphy@ti.com> <20181219162626.12297-2-dmurphy@ti.com> <2d2d5dcd-9c23-e901-daac-9b79aa5a5e82@ti.com> <6c62956e-7789-58ba-5437-f2e033f2825c@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <6c62956e-7789-58ba-5437-f2e033f2825c@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Jacek Anaszewski , robh+dt@kernel.org, pavel@ucw.cz Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org List-Id: linux-leds@vger.kernel.org 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 >>>> --- >>>>    .../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. 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. Dan -- ------------------ Dan Murphy