diff mbox

[v4,2/2] ARM: dts: at_xdmac: add bindings documentation

Message ID 1410792622-22621-3-git-send-email-ludovic.desroches@atmel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ludovic Desroches Sept. 15, 2014, 2:50 p.m. UTC 
Add bindings documentation for the new Atmel DMA controller (XDMAC)
introduced with SAMA5D4.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
---
 .../devicetree/bindings/dma/atmel-xdma.txt         | 48 ++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt

Comments

Nicolas Ferre Sept. 17, 2014, 8:30 a.m. UTC | #1 
On 15/09/2014 16:50, Ludovic Desroches :
> Add bindings documentation for the new Atmel DMA controller (XDMAC)
> introduced with SAMA5D4.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> ---
>  .../devicetree/bindings/dma/atmel-xdma.txt         | 48 ++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> new file mode 100644
> index 0000000..647f099
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> @@ -0,0 +1,48 @@
> +* Atmel Extensible Direct Memory Access Controller (XDMAC)
> +
> +* XDMA Controller
> +Required properties:
> +- compatible: Should be "atmel,<chip>-dma".

You must add the "chip" used here: like:
<chip> compatible description:
- sama5d4: first SoC adding the XDMAC

> +- reg: Should contain DMA registers location and length.
> +- interrupts: Should contain DMA interrupt.
> +- #dma-cells: Must be <2>, used to represent the number of integer cells in
> +the dmas property of client devices.
> +  - The 1st cell specifies the memory interface (16 most significant bits) and
> +  the peripheral interface (16 less significant bits) to use.
> +  - The 2nd cell specifies the channel configuration register:
> +    - bit 30-24: PERID, peripheral identifier.
> +
> +Example:
> +
> +dma1: dma-controller@f0004000 {
> +	compatible = "atmel,sama5d4-dma";
> +	reg = <0xf0004000 0x200>;
> +	interrupts = <50 4 0>;
> +	#dma-cells = <2>;
> +};
> +
> +
> +* DMA clients
> +DMA clients connected to the Atmel XDMA controller must use the format
> +described in the dma.txt file, using a two-cell specifier for each channel.
> +The three cells in order are:
> +1. A phandle pointing to the DMA controller.
> +2. The memory interface (16 most significant bits), the peripheral interface
> +(16 less significant bits).
> +3. Channel configuration register. Configurable fields are:
> +  - bit 30-24: PERID, peripheral identifier.
> +
> +Example:
> +
> +i2c2: i2c@f8024000 {
> +	compatible = "atmel,at91sam9x5-i2c";
> +	reg = <0xf8024000 0x4000>;
> +	interrupts = <34 4 6>;
> +	dmas = <&dma1
> +		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
> +		AT91_XDMAC_DT_PERID(6)>,
> +	       <&dma1
> +		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
> +		AT91_XDMAC_DT_PERID(7)>;
> +	dma-names = "tx", "rx";
> +};
> 

Otherwise, you can add my:

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Thanks, bye,
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
new file mode 100644
index 0000000..647f099
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
@@ -0,0 +1,48 @@ 
+* Atmel Extensible Direct Memory Access Controller (XDMAC)
+
+* XDMA Controller
+Required properties:
+- compatible: Should be "atmel,<chip>-dma".
+- reg: Should contain DMA registers location and length.
+- interrupts: Should contain DMA interrupt.
+- #dma-cells: Must be <2>, used to represent the number of integer cells in
+the dmas property of client devices.
+  - The 1st cell specifies the memory interface (16 most significant bits) and
+  the peripheral interface (16 less significant bits) to use.
+  - The 2nd cell specifies the channel configuration register:
+    - bit 30-24: PERID, peripheral identifier.
+
+Example:
+
+dma1: dma-controller@f0004000 {
+	compatible = "atmel,sama5d4-dma";
+	reg = <0xf0004000 0x200>;
+	interrupts = <50 4 0>;
+	#dma-cells = <2>;
+};
+
+
+* DMA clients
+DMA clients connected to the Atmel XDMA controller must use the format
+described in the dma.txt file, using a two-cell specifier for each channel.
+The three cells in order are:
+1. A phandle pointing to the DMA controller.
+2. The memory interface (16 most significant bits), the peripheral interface
+(16 less significant bits).
+3. Channel configuration register. Configurable fields are:
+  - bit 30-24: PERID, peripheral identifier.
+
+Example:
+
+i2c2: i2c@f8024000 {
+	compatible = "atmel,at91sam9x5-i2c";
+	reg = <0xf8024000 0x4000>;
+	interrupts = <34 4 6>;
+	dmas = <&dma1
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(6)>,
+	       <&dma1
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(7)>;
+	dma-names = "tx", "rx";
+};