# \[PATCH\] backlight: arcxcnn: devicetree bindings for ArticSand devices

- Subsystems: OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS, THE REST
- Maintainers: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
- List: linux-fbdev
- 2 messages, 2 authors
- Page: https://ratatoskr.run/linux-fbdev/2016/08/4819985/t

## \[PATCH\] backlight: arcxcnn: devicetree bindings for ArticSand devices

- From: Olimpiu Dejeu \<hidden\>
- Date: 2016-08-22 19:11:35 
- Message: https://ratatoskr.run/linux-fbdev/2016/08/4819985.md

```text
This is the device tree bindings documentation file

Signed-off-by: Olimpiu Dejeu <redacted>

---
 .../bindings/video/backlight/arcxcnn.txt           | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/video/backlight/arcxcnn.txt

diff --git a/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt b/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt
new file mode 100644
index 0000000..9cd7315
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt
@@ -0,0 +1,29 @@
+arcxcnn bindings
+
+Required properties:
+  - compatible: "arc,arcxcnn", "arc,arc2c0608"
+  - reg: I2C slave address (u8)
+
+Optional properties:
+  - bl-name: Backlight device name (string)
+  - init-brt: Initial value of backlight brightness (u32) low 16 bits used
+  - pwm-period: PWM period value. Set only PWM input mode used (u32)
+  - prg-addr: Register address of ROM area to be updated (u32) low 8 bits used
+  - prg-val: Register value to be updated (u32) low 8 bits used
+
+Example:
+
+	/* ARC2C0608 */
+	backlight@30 {
+		compatible = "arc,arc2c0608";
+		reg = <0x30>;
+
+		init-brt = <123>;
+
+		/* LED0+1 string enabled */
+		prg_06h {
+			prg-addr = <0x06>;
+			prg-val = <0x83>;
+		};
+
+	};
-- 
1.9.1

```

## Re: \[PATCH\] backlight: arcxcnn: devicetree bindings for ArticSand devices

- From: Rob Herring \<robh@kernel.org\>
- Date: 2016-08-23 18:22:33 
- Message: https://ratatoskr.run/linux-fbdev/2016/08/4820838.md

```text
On Mon, Aug 22, 2016 at 03:11:24PM -0400, Olimpiu Dejeu wrote:
> This is the device tree bindings documentation file
> 
> Signed-off-by: Olimpiu Dejeu <redacted>
> 
> ---
>  .../bindings/video/backlight/arcxcnn.txt           | 29 ++++++++++++++++++++++

Check your directory location. Things have moved.

>  1 file changed, 29 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/video/backlight/arcxcnn.txt
> 
> diff --git a/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt b/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt
> new file mode 100644
> index 0000000..9cd7315
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/video/backlight/arcxcnn.txt
> @@ -0,0 +1,29 @@
> +arcxcnn bindings
> +
> +Required properties:
> +  - compatible: "arc,arcxcnn", "arc,arc2c0608"

One per line please.

Is arcxcnn a specific chip? If not drop it. No wildcards in compatible 
strings.

> +  - reg: I2C slave address (u8)
> +
> +Optional properties:
> +  - bl-name: Backlight device name (string)

Use the common bindings. label?

> +  - init-brt: Initial value of backlight brightness (u32) low 16 bits used

Use common bindings.

> +  - pwm-period: PWM period value. Set only PWM input mode used (u32)
> +  - prg-addr: Register address of ROM area to be updated (u32) low 8 bits used
> +  - prg-val: Register value to be updated (u32) low 8 bits used

What is this for? This should be a specific property or properties to do 
explicit things, not a generic fill registers/rom with magic values.

> +
> +Example:
> +
> +	/* ARC2C0608 */
> +	backlight@30 {
> +		compatible = "arc,arc2c0608";
> +		reg = <0x30>;
> +
> +		init-brt = <123>;
> +
> +		/* LED0+1 string enabled */
> +		prg_06h {
> +			prg-addr = <0x06>;
> +			prg-val = <0x83>;
> +		};
> +
> +	};
> -- 
> 1.9.1
> 
> --
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```