diff mbox series

[v2,2/3] dt-bindings: backlight: add lm3630a bindings

Message ID 20190401103034.21062-3-masneyb@onstation.org (mailing list archive)
State New, archived
Headers show
Series backlight: lm3630a: bug fix and device tree support | expand

Commit Message

Brian Masney April 1, 2019, 10:30 a.m. UTC
Add new backlight bindings for the TI LM3630A dual-string white LED.

Signed-off-by: Brian Masney <masneyb@onstation.org>
---
 .../leds/backlight/lm3630a-backlight.yaml     | 112 ++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml

Comments

Brian Masney April 1, 2019, 11:04 p.m. UTC | #1
On Mon, Apr 01, 2019 at 11:39:26PM +0200, Pavel Machek wrote:
> On Mon 2019-04-01 06:30:33, Brian Masney wrote:
> > Add new backlight bindings for the TI LM3630A dual-string white LED.
> > 
> > Signed-off-by: Brian Masney <masneyb@onstation.org>
> > ---
> >  .../leds/backlight/lm3630a-backlight.yaml     | 112
> ++++++++++++++++++
> 
> What is that? Is it future of all the bindings?
> 
> Up to device tree people, I guess, but...

Yes, this is the future format of the bindings so that automated
validation can be performed. See
Documentation/devicetree/writing-schema.md.

Brian
Dan Murphy April 2, 2019, 12:56 p.m. UTC | #2
Hello

On 4/1/19 5:30 AM, Brian Masney wrote:
> Add new backlight bindings for the TI LM3630A dual-string white LED.
> 
> Signed-off-by: Brian Masney <masneyb@onstation.org>
> ---
>  .../leds/backlight/lm3630a-backlight.yaml     | 112 ++++++++++++++++++
>  1 file changed, 112 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml
> new file mode 100644
> index 000000000000..42a8c59d237a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml
> @@ -0,0 +1,112 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/backlight/lm3630a-backlight.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI LM3630A High-Efficiency Dual-String White LED
> +
> +maintainers:
> +  - Lee Jones <lee.jones@linaro.org>
> +  - Daniel Thompson <daniel.thompson@linaro.org>
> +  - Jingoo Han <jingoohan1@gmail.com>
> +
> +description: |
> +  The LM3630A is a current-mode boost converter which supplies the power and
> +  controls the current in up to two strings of 10 LEDs per string.
> +  https://www.ti.com/product/LM3630A
> +
> +properties:
> +  compatible:
> +    const: ti,lm3630a
> +
> +  reg:
> +    maxItems: 1
> +

No description on the reg here.  Assumed to be the i2c address?

> +  ti,linear-mapping-mode:
> +    description: |
> +      Enable linear mapping mode. If disabled, then it will use exponential
> +      mapping mode in which the ramp up/down appears to have a more uniform
> +      tranisiton to the human eye.

s/tranisiton/transition

> +    type: boolean
> +
> +required:
> +  - compatible
> +  - reg
> +
> +patternProperties:
> +  "^led*$":
> +    type: object
> +    description: |
> +      Properties for a string of connected LEDs.
> +

I have written a few of these drivers that have control bank support to control.  We have
been defining the reg property as the control bank id

reg 0 - Control bank A
reg 1 - Control bank B

Then use the led-sources to define what outputs are associated with which control bank.

This way the hardware can just have CB B enabled without CB A.

something like below would allow just control bank B to be enabled.

led@1 {
	reg = <1>;
	label = "main-lcd";
	default-brightness = <200>;
	max-brightness = <255>;
};

This would connect control bank B to control bank A.  Or just use a flag to denote to connect them
and not use led-sources.  But led-sources is the property of choice.

led@0 {
	reg = <0>;
	led-sources = < 0 1 >;
	label = "main-lcd";
	default-brightness = <200>;
	max-brightness = <255>;
};

And just the presence of 2 child nodes would indicate individual bank control
led@0 {
	reg = <0>;
	label = "main-lcd";
	default-brightness = <200>;
	max-brightness = <255>;
};

led@1 {
	reg = <1>;
	label = "main-keypad";
	default-brightness = <200>;
	max-brightness = <255>;
};

> +    properties:
> +      label:
> +        description: |
> +          The label for this LED. If omitted, the label is taken from the node
> +          name (excluding the unit address). It has to uniquely identify a
> +          device, i.e. no other LED class device can be assigned the same label.
> +
> +      led-sources:
> +        description: |
> +          List of device current outputs the LED is connected to.
> +        allOf:
> +          - $ref: /schemas/types.yaml#/definitions/uint32-array
> +          - minItems: 1
> +            maxItems: 2
> +            items:
> +              minimum: 0
> +              maximum: 1
> +

label and led-sources are already defined in the common.txt no need to redefine them here.

> +      default-brightness:
> +        description: Default brightness level on boot.
> +        minimum: 0
> +        maximum: 255
> +
> +      max-brightness:
> +        description: Maximum brightness level on boot.

This is not the max brightness on boot.  This is the max brightness that is allowed during runtime.

Dan

> +        minimum: 0
> +        maximum: 255
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        lm3630a_bl@38 {
> +                compatible = "ti,lm3630a";
> +                status = "ok";
> +                reg = <0x38>;
> +
> +                led {
> +                        label = "main-lcd";
> +                        led-sources = <0 1>;
> +                        default-brightness = <200>;
> +                        max-brightness = <255>;
> +                };
> +        };
> +    };
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        lm3630a_bl@38 {
> +                compatible = "ti,lm3630a";
> +                status = "ok";
> +                reg = <0x38>;
> +
> +                led-bank-a {
> +                        led-sources = <0>;
> +                        default-brightness = <150>;
> +                        ti,linear-mapping-mode;
> +                };
> +
> +                led-bank-b {
> +                        led-sources = <1>;
> +                        default-brightness = <225>;
> +                        ti,linear-mapping-mode;
> +                };
> +        };
> +    };
>
Brian Masney April 2, 2019, 1:24 p.m. UTC | #3
On Tue, Apr 02, 2019 at 07:56:55AM -0500, Dan Murphy wrote:
> This would connect control bank B to control bank A.  Or just use a flag to denote to connect them
> and not use led-sources.  But led-sources is the property of choice.
> 
> led@0 {
> 	reg = <0>;
> 	led-sources = < 0 1 >;
> 	label = "main-lcd";
> 	default-brightness = <200>;
> 	max-brightness = <255>;
> };

OK, I see. I wondered how we could do that in device tree.

> > +    properties:
> > +      label:
> > +        description: |
> > +          The label for this LED. If omitted, the label is taken from the node
> > +          name (excluding the unit address). It has to uniquely identify a
> > +          device, i.e. no other LED class device can be assigned the same label.
> > +
> > +      led-sources:
> > +        description: |
> > +          List of device current outputs the LED is connected to.
> > +        allOf:
> > +          - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +          - minItems: 1
> > +            maxItems: 2
> > +            items:
> > +              minimum: 0
> > +              maximum: 1
> > +
> 
> label and led-sources are already defined in the common.txt no need to redefine them here.

If I'm going to use the new-style bindings, then I'll need to convert
common.txt over to use the new format as well so that the automated
schema validations will work. I'm willing to do that work if there is
interest from the LED / backlight maintainers. The main issue is that
there are 62 references to the file common.txt in the directory
Documentation/devicetree/bindings/leds/. Would the maintainers prefer:

- Once common.txt is converted to common.yaml, make common.txt only
  have a line stating that the common bindings were moved into
  common.yaml. We can remove this file once all of the other bindings
  are converted to the new-style format.

- Update all references to common.txt to common.yaml. (1 patch or 62
  patches?)

- Or, just go with the older-style binding format for now.

Thanks Dan for your other comments. They make sense and I'll incorporate
those changes into my next version.

Brian
Dan Murphy April 2, 2019, 1:44 p.m. UTC | #4
Brian

On 4/2/19 8:24 AM, Brian Masney wrote:
> On Tue, Apr 02, 2019 at 07:56:55AM -0500, Dan Murphy wrote:
>> This would connect control bank B to control bank A.  Or just use a flag to denote to connect them
>> and not use led-sources.  But led-sources is the property of choice.
>>
>> led@0 {
>> 	reg = <0>;
>> 	led-sources = < 0 1 >;
>> 	label = "main-lcd";
>> 	default-brightness = <200>;
>> 	max-brightness = <255>;
>> };
> 
> OK, I see. I wondered how we could do that in device tree.
> 
>>> +    properties:
>>> +      label:
>>> +        description: |
>>> +          The label for this LED. If omitted, the label is taken from the node
>>> +          name (excluding the unit address). It has to uniquely identify a
>>> +          device, i.e. no other LED class device can be assigned the same label.
>>> +
>>> +      led-sources:
>>> +        description: |
>>> +          List of device current outputs the LED is connected to.
>>> +        allOf:
>>> +          - $ref: /schemas/types.yaml#/definitions/uint32-array
>>> +          - minItems: 1
>>> +            maxItems: 2
>>> +            items:
>>> +              minimum: 0
>>> +              maximum: 1
>>> +
>>
>> label and led-sources are already defined in the common.txt no need to redefine them here.
> 
> If I'm going to use the new-style bindings, then I'll need to convert
> common.txt over to use the new format as well so that the automated
> schema validations will work. I'm willing to do that work if there is
> interest from the LED / backlight maintainers. The main issue is that
> there are 62 references to the file common.txt in the directory
> Documentation/devicetree/bindings/leds/. Would the maintainers prefer:
> 
> - Once common.txt is converted to common.yaml, make common.txt only
>   have a line stating that the common bindings were moved into
>   common.yaml. We can remove this file once all of the other bindings
>   are converted to the new-style format.
> 
> - Update all references to common.txt to common.yaml. (1 patch or 62
>   patches?)
> 
> - Or, just go with the older-style binding format for now.
> 
> Thanks Dan for your other comments. They make sense and I'll incorporate
> those changes into my next version.
> 

That is up to the maintainers.

Also one other comment I noticed when reviewing the code that there is no definition to
which child led properties are optional and which are required?

Dan

> Brian
>
Rob Herring April 3, 2019, 1:50 a.m. UTC | #5
On Tue, Apr 2, 2019 at 8:24 AM Brian Masney <masneyb@onstation.org> wrote:
>
> On Tue, Apr 02, 2019 at 07:56:55AM -0500, Dan Murphy wrote:
> > This would connect control bank B to control bank A.  Or just use a flag to denote to connect them
> > and not use led-sources.  But led-sources is the property of choice.
> >
> > led@0 {
> >       reg = <0>;
> >       led-sources = < 0 1 >;
> >       label = "main-lcd";
> >       default-brightness = <200>;
> >       max-brightness = <255>;
> > };
>
> OK, I see. I wondered how we could do that in device tree.
>
> > > +    properties:
> > > +      label:
> > > +        description: |
> > > +          The label for this LED. If omitted, the label is taken from the node
> > > +          name (excluding the unit address). It has to uniquely identify a
> > > +          device, i.e. no other LED class device can be assigned the same label.
> > > +
> > > +      led-sources:
> > > +        description: |
> > > +          List of device current outputs the LED is connected to.
> > > +        allOf:
> > > +          - $ref: /schemas/types.yaml#/definitions/uint32-array
> > > +          - minItems: 1
> > > +            maxItems: 2
> > > +            items:
> > > +              minimum: 0
> > > +              maximum: 1
> > > +
> >
> > label and led-sources are already defined in the common.txt no need to redefine them here.
>
> If I'm going to use the new-style bindings, then I'll need to convert
> common.txt over to use the new format as well so that the automated
> schema validations will work. I'm willing to do that work if there is
> interest from the LED / backlight maintainers. The main issue is that
> there are 62 references to the file common.txt in the directory
> Documentation/devicetree/bindings/leds/. Would the maintainers prefer:

That would be awesome.

> - Once common.txt is converted to common.yaml, make common.txt only
>   have a line stating that the common bindings were moved into
>   common.yaml. We can remove this file once all of the other bindings
>   are converted to the new-style format.
>
> - Update all references to common.txt to common.yaml. (1 patch or 62
>   patches?)

I'd probably go with the former if I had to pick. The real
complication here is there's some other changes in flight.

>
> - Or, just go with the older-style binding format for now.

I'm okay if you write it with the assumption that the common
properties have a schema even if they don't yet. All that means is you
don't need to define the type, but only the additional constraints.
There doesn't have to be a reference back to the common property
(those references tend to get broken as we can see here). With
everything as structured data, we could even generate references or
have some tool that can lookup the common definitions.

Rob
Brian Masney April 7, 2019, 11:28 a.m. UTC | #6
Hi Dan,

On Tue, Apr 02, 2019 at 08:44:22AM -0500, Dan Murphy wrote:
> Also one other comment I noticed when reviewing the code that there is no definition to
> which child led properties are optional and which are required?

With the new YAML bindings, there is a separate toplevel 'required' tag in
the schema. Here is a snippet from my last submission that illustrates
this:

    properties:
      compatible:
        const: ti,lm3630a
    
      reg:
        maxItems: 1
    
      ti,linear-mapping-mode:
        description: |
          Enable linear mapping mode. If disabled, then it will use exponential
          mapping mode in which the ramp up/down appears to have a more uniform
          transition to the human eye.
        type: boolean
    
    required:
      - compatible
      - reg

So 'ti,linear-mapping-mode' is optional in this example.

> > +      led-sources:
> > +        description: |
> > +          List of device current outputs the LED is connected to.
> > +        allOf:
> > +          - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +          - minItems: 1
> > +            maxItems: 2
> > +            items:
> > +              minimum: 0
> > +              maximum: 1
> > +
> 
> label and led-sources are already defined in the common.txt no need to redefine them here.

We'll still need to define the led-sources and label in this binding
with the new format even though it will also be in the LED common
bindings. We won't have to put the common things like the description
since that information will come from the common binding. We only need
to specify the additional constraints like the min/max number of items
and the min/max value for each item for this particular example.

Brian
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml
new file mode 100644
index 000000000000..42a8c59d237a
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/lm3630a-backlight.yaml
@@ -0,0 +1,112 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/lm3630a-backlight.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI LM3630A High-Efficiency Dual-String White LED
+
+maintainers:
+  - Lee Jones <lee.jones@linaro.org>
+  - Daniel Thompson <daniel.thompson@linaro.org>
+  - Jingoo Han <jingoohan1@gmail.com>
+
+description: |
+  The LM3630A is a current-mode boost converter which supplies the power and
+  controls the current in up to two strings of 10 LEDs per string.
+  https://www.ti.com/product/LM3630A
+
+properties:
+  compatible:
+    const: ti,lm3630a
+
+  reg:
+    maxItems: 1
+
+  ti,linear-mapping-mode:
+    description: |
+      Enable linear mapping mode. If disabled, then it will use exponential
+      mapping mode in which the ramp up/down appears to have a more uniform
+      tranisiton to the human eye.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+patternProperties:
+  "^led*$":
+    type: object
+    description: |
+      Properties for a string of connected LEDs.
+
+    properties:
+      label:
+        description: |
+          The label for this LED. If omitted, the label is taken from the node
+          name (excluding the unit address). It has to uniquely identify a
+          device, i.e. no other LED class device can be assigned the same label.
+
+      led-sources:
+        description: |
+          List of device current outputs the LED is connected to.
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/uint32-array
+          - minItems: 1
+            maxItems: 2
+            items:
+              minimum: 0
+              maximum: 1
+
+      default-brightness:
+        description: Default brightness level on boot.
+        minimum: 0
+        maximum: 255
+
+      max-brightness:
+        description: Maximum brightness level on boot.
+        minimum: 0
+        maximum: 255
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        lm3630a_bl@38 {
+                compatible = "ti,lm3630a";
+                status = "ok";
+                reg = <0x38>;
+
+                led {
+                        label = "main-lcd";
+                        led-sources = <0 1>;
+                        default-brightness = <200>;
+                        max-brightness = <255>;
+                };
+        };
+    };
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        lm3630a_bl@38 {
+                compatible = "ti,lm3630a";
+                status = "ok";
+                reg = <0x38>;
+
+                led-bank-a {
+                        led-sources = <0>;
+                        default-brightness = <150>;
+                        ti,linear-mapping-mode;
+                };
+
+                led-bank-b {
+                        led-sources = <1>;
+                        default-brightness = <225>;
+                        ti,linear-mapping-mode;
+                };
+        };
+    };