Re: [PATCH RFC v9 5/6] dma: mpc512x: add device tree binding document
From: Mark Rutland <hidden>
Date: 2014-03-13 18:09:16
Also in:
linuxppc-dev
On Wed, Mar 12, 2014 at 11:47:54AM +0000, Alexander Popov wrote:
quoted hunk
From: Gerhard Sittig <redacted> introduce a device tree binding document for the MPC512x DMA controller Signed-off-by: Gerhard Sittig <redacted> [ a13xp0p0v88-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org: turn this into a separate patch ] --- .../devicetree/bindings/dma/mpc512x-dma.txt | 55 ++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/mpc512x-dma.txtdiff --git a/Documentation/devicetree/bindings/dma/mpc512x-dma.txt b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt new file mode 100644 index 0000000..a4867d5 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/mpc512x-dma.txt@@ -0,0 +1,55 @@ +* Freescale MPC512x DMA Controller + +The DMA controller in the Freescale MPC512x SoC can move blocks of +memory contents between memory and peripherals or memory to memory. + +Refer to the "Generic DMA Controller and DMA request bindings" description +in the dma.txt file for a more detailled discussion of the binding. The +MPC512x DMA engine binding follows the common scheme, but doesn't provide +support for the optional channels and requests counters (those values are +derived from the detected hardware features) and has a fixed client +specifier length of 1 integer cell (the value is the DMA channel, since +the DMA controller uses a fixed assignment of request lines per channel). + + +DMA controller node properties: + +Required properties: +- compatible: should be "fsl,mpc5121-dma" +- reg: address and size of the DMA controller's register set +- interrupts: interrupt spec for the DMA controller + +Optional properties: +- #dma-cells: must be <1>, describes the number of integer cells + needed to specify the 'dmas' property in client nodes, + strongly recommended since common client helper code + uses this property
Describe what you expect this cell to contain, not the #dma-cells binding in general. The DMA bindings already cover that. What are valid value that clients may use, and what do they mean?
+
+Example:
+
+ dma0: dma@14000 {
+ compatible = "fsl,mpc5121-dma";
+ reg = <0x14000 0x1800>;
+ interrupts = <65 0x8>;
+ #dma-cells = <1>;
+ };
+
+
+Client node properties:
+
+Required properties:
+- dmas: list of DMA specifiers, consisting each of a handle
+ for the DMA controller and integer cells to specify
+ the channel used within the DMA controller
+- dma-names: list of identifier strings for the DMA specifiers,
+ client device driver code uses these strings to
+ have DMA channels looked up at the controllerList the exact names you expect, or the dma-names property is useless. Thanks, Mark.
+
+Example:
+
+ sdhc@1500 {
+ compatible = "fsl,mpc5121-sdhc";
+ /* ... */
+ dmas = <&dma0 30>;
+ dma-names = "rx-tx";
+ };
--
1.8.4.2
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