diff options
| author | Simon Horman <horms+renesas@verge.net.au> | 2019-07-24 13:49:46 +0200 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-07-29 12:23:22 +0530 |
| commit | ffbb569b9cee1fa0277a48d7925dbed1356dbb32 (patch) | |
| tree | 74d82c7e02d59c7669abe69a50ba198783866225 /Documentation/devicetree/bindings/dma/renesas,shdma.txt | |
| parent | edd14218bd663e4dd2f1c8f4eed84f92ada93c9d (diff) | |
dt-bindings: dmaengine: shdma: Rename bindings documentation file
Rename the bindings documentation file for shdma
from shdma.txt to renesas,shdma.txt.
This is part of an ongoing effort to name bindings documentation files for
Renesas IP blocks consistently, in line with the compat strings they
document.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Link: https://lore.kernel.org/r/20190724114946.14021-1-horms+renesas@verge.net.au
[vkoul: add subsystem name]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'Documentation/devicetree/bindings/dma/renesas,shdma.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/dma/renesas,shdma.txt | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/dma/renesas,shdma.txt b/Documentation/devicetree/bindings/dma/renesas,shdma.txt new file mode 100644 index 000000000000..a91920a49433 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/renesas,shdma.txt @@ -0,0 +1,84 @@ +* SHDMA Device Tree bindings + +Sh-/r-mobile and R-Car systems often have multiple identical DMA controller +instances, capable of serving any of a common set of DMA slave devices, using +the same configuration. To describe this topology we require all compatible +SHDMA DT nodes to be placed under a DMA multiplexer node. All such compatible +DMAC instances have the same number of channels and use the same DMA +descriptors. Therefore respective DMA DT bindings can also all be placed in the +multiplexer node. Even if there is only one such DMAC instance on a system, it +still has to be placed under such a multiplexer node. + +* DMA multiplexer + +Required properties: +- compatible: should be "renesas,shdma-mux" +- #dma-cells: should be <1>, see "dmas" property below + +Optional properties (currently unused): +- dma-channels: number of DMA channels +- dma-requests: number of DMA request signals + +* DMA controller + +Required properties: +- compatible: should be of the form "renesas,shdma-<soc>", where <soc> should + be replaced with the desired SoC model, e.g. + "renesas,shdma-r8a73a4" for the system DMAC on r8a73a4 SoC + +Example: + dmac: dma-multiplexer@0 { + compatible = "renesas,shdma-mux"; + #dma-cells = <1>; + dma-channels = <20>; + dma-requests = <256>; + #address-cells = <2>; + #size-cells = <2>; + ranges; + + dma0: dma-controller@e6700020 { + compatible = "renesas,shdma-r8a73a4"; + reg = <0 0xe6700020 0 0x89e0>; + interrupt-parent = <&gic>; + interrupts = <0 220 4 + 0 200 4 + 0 201 4 + 0 202 4 + 0 203 4 + 0 204 4 + 0 205 4 + 0 206 4 + 0 207 4 + 0 208 4 + 0 209 4 + 0 210 4 + 0 211 4 + 0 212 4 + 0 213 4 + 0 214 4 + 0 215 4 + 0 216 4 + 0 217 4 + 0 218 4 + 0 219 4>; + interrupt-names = "error", + "ch0", "ch1", "ch2", "ch3", + "ch4", "ch5", "ch6", "ch7", + "ch8", "ch9", "ch10", "ch11", + "ch12", "ch13", "ch14", "ch15", + "ch16", "ch17", "ch18", "ch19"; + }; + }; + +* DMA client + +Required properties: +- dmas: a list of <[DMA multiplexer phandle] [MID/RID value]> pairs, + where MID/RID values are fixed handles, specified in the SoC + manual +- dma-names: a list of DMA channel names, one per "dmas" entry + +Example: + dmas = <&dmac 0xd1 + &dmac 0xd2>; + dma-names = "tx", "rx"; |