diff mbox

[PATCHv2,1/3] Documentation: ad5064: Added devicetree bindings documentation

Message ID 1444650634-12025-1-git-send-email-paul.cercueil@analog.com
State New, archived
Headers show

Commit Message

Paul Cercueil Oct. 12, 2015, 11:50 a.m. UTC
Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
---
 .../devicetree/bindings/iio/dac/ad5064.txt         | 48 ++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/ad5064.txt

 v2: No change in this patch

Comments

Mark Rutland Oct. 12, 2015, 3:18 p.m. UTC | #1
On Mon, Oct 12, 2015 at 01:50:32PM +0200, Paul Cercueil wrote:
> Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
> ---
>  .../devicetree/bindings/iio/dac/ad5064.txt         | 48 ++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/ad5064.txt
> 
>  v2: No change in this patch
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/ad5064.txt b/Documentation/devicetree/bindings/iio/dac/ad5064.txt
> new file mode 100644
> index 0000000..fa2d328
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/ad5064.txt
> @@ -0,0 +1,48 @@
> +Analog Devices AD5064 DAC device driver
> +
> +Required properties:
> +	- compatible: Must be one of:
> +		* "adi,ad5024"
> +		* "adi,ad5025"
> +		* "adi,ad5044"
> +		* "adi,ad5045"
> +		* "adi,ad5064"
> +		* "adi,ad5064-1"
> +		* "adi,ad5065"
> +		* "adi,ad5628-1"
> +		* "adi,ad5628-2"
> +		* "adi,ad5648-1"
> +		* "adi,ad5648-2"
> +		* "adi,ad5666-1"
> +		* "adi,ad5666-2"
> +		* "adi,ad5668-1"
> +		* "adi,ad5668-2"
> +		* "adi,ad5668-3"
> +	- reg: SPI chip select number for the device
> +	- spi-max-frequency: Max SPI frequency to use (< 30000000)
> +	- vrefA-supply, vrefB-supply: phandles to external reference voltage
> +	  supplies for channels 0 and 1 respectively.
> +	  This property must be present for ad5024, ad5025, ad5044, ad5045,
> +	  ad5064, ad5065.
> +	- vrefC-supply, vrefD-supply: phandles to external reference voltage
> +	  supplies for channels 2 and 3 respectively.
> +	  This property must be present for ad5024, ad5044, ad5064.

Nit: please don't use CamelCase property names. just have vref-a-supply
and so on.

> +
> +Optional properties:
> +	- vref-supply: phandle to the external reference voltage supply.
> +	  This should only be set if there is an external reference voltage
> +	  connected to the vref or vref[A-D] pins.

I don't understand. Surely the latter case means you're describing the
same supply twice (as it should already be in vref*-supply)?

What vref pins does the HW actually have?

> +	  If the property is not set, the internal reference voltage supply
> +	  is used if present.
> +	  This property can be used with ad5064-1, ad5628-1, ad5628-2, ad5648-1,
> +	  ad5648-2, ad5666-1, ad5666-2, ad5668-1, ad5668-2, ad5668-3.
> +
> +Example:
> +
> +		ad5668-2@4 {
> +			compatible = "adi,ad5668-2";
> +			reg = <4>;
> +			spi-max-frequency = <10000000>;
> +			adi,use-external-reference;

This is undocumented (and unused by the driver?).

Thanks,
Mark.
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Lars-Peter Clausen Oct. 13, 2015, 11:11 a.m. UTC | #2
>> +
>> +Optional properties:
>> +	- vref-supply: phandle to the external reference voltage supply.
>> +	  This should only be set if there is an external reference voltage
>> +	  connected to the vref or vref[A-D] pins.
> 
> I don't understand. Surely the latter case means you're describing the
> same supply twice (as it should already be in vref*-supply)?
> 
> What vref pins does the HW actually have?

Some off the devices supported by the binding have a shared reference for
all DAC outputs, while others have a separate reference for each output. In
addition to that some of them have an internal reference that can used, in
which case the external reference is optional, otherwise the external
reference is required. The bindings documentation should clarify on which
applies to which device.

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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/iio/dac/ad5064.txt b/Documentation/devicetree/bindings/iio/dac/ad5064.txt
new file mode 100644
index 0000000..fa2d328
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/ad5064.txt
@@ -0,0 +1,48 @@ 
+Analog Devices AD5064 DAC device driver
+
+Required properties:
+	- compatible: Must be one of:
+		* "adi,ad5024"
+		* "adi,ad5025"
+		* "adi,ad5044"
+		* "adi,ad5045"
+		* "adi,ad5064"
+		* "adi,ad5064-1"
+		* "adi,ad5065"
+		* "adi,ad5628-1"
+		* "adi,ad5628-2"
+		* "adi,ad5648-1"
+		* "adi,ad5648-2"
+		* "adi,ad5666-1"
+		* "adi,ad5666-2"
+		* "adi,ad5668-1"
+		* "adi,ad5668-2"
+		* "adi,ad5668-3"
+	- reg: SPI chip select number for the device
+	- spi-max-frequency: Max SPI frequency to use (< 30000000)
+	- vrefA-supply, vrefB-supply: phandles to external reference voltage
+	  supplies for channels 0 and 1 respectively.
+	  This property must be present for ad5024, ad5025, ad5044, ad5045,
+	  ad5064, ad5065.
+	- vrefC-supply, vrefD-supply: phandles to external reference voltage
+	  supplies for channels 2 and 3 respectively.
+	  This property must be present for ad5024, ad5044, ad5064.
+
+Optional properties:
+	- vref-supply: phandle to the external reference voltage supply.
+	  This should only be set if there is an external reference voltage
+	  connected to the vref or vref[A-D] pins.
+	  If the property is not set, the internal reference voltage supply
+	  is used if present.
+	  This property can be used with ad5064-1, ad5628-1, ad5628-2, ad5648-1,
+	  ad5648-2, ad5666-1, ad5666-2, ad5668-1, ad5668-2, ad5668-3.
+
+Example:
+
+		ad5668-2@4 {
+			compatible = "adi,ad5668-2";
+			reg = <4>;
+			spi-max-frequency = <10000000>;
+			adi,use-external-reference;
+			vref-supply = <&vref_supply>;
+		};