linux-stable/Documentation/devicetree/bindings/dma/renesas,nbpfaxi.txt
Simon Horman 14c2a7b934 dt-bindings: dmaengine: nbpfaxi: Rename bindings documentation file
Rename the device tree bindings for renesas "Type-AXI" NBPFAXI* DMA
controllers from nbpfaxi.txt to renesas,nbpfaxi.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/20190819135244.18183-1-horms+renesas@verge.net.au
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-08-20 16:37:18 +05:30

69 lines
1.9 KiB
Text

* Renesas "Type-AXI" NBPFAXI* DMA controllers
* DMA controller
Required properties
- compatible: must be one of
"renesas,nbpfaxi64dmac1b4"
"renesas,nbpfaxi64dmac1b8"
"renesas,nbpfaxi64dmac1b16"
"renesas,nbpfaxi64dmac4b4"
"renesas,nbpfaxi64dmac4b8"
"renesas,nbpfaxi64dmac4b16"
"renesas,nbpfaxi64dmac8b4"
"renesas,nbpfaxi64dmac8b8"
"renesas,nbpfaxi64dmac8b16"
- #dma-cells: must be 2: the first integer is a terminal number, to which this
slave is connected, the second one is flags. Flags is a bitmask
with the following bits defined:
#define NBPF_SLAVE_RQ_HIGH 1
#define NBPF_SLAVE_RQ_LOW 2
#define NBPF_SLAVE_RQ_LEVEL 4
Optional properties:
- max-burst-mem-read: limit burst size for memory reads
(DMA_MEM_TO_MEM/DMA_MEM_TO_DEV) to this value, specified in bytes, rather
than using the maximum burst size allowed by the hardware's buffer size.
- max-burst-mem-write: limit burst size for memory writes
(DMA_DEV_TO_MEM/DMA_MEM_TO_MEM) to this value, specified in bytes, rather
than using the maximum burst size allowed by the hardware's buffer size.
If both max-burst-mem-read and max-burst-mem-write are set, DMA_MEM_TO_MEM
will use the lower value.
You can use dma-channels and dma-requests as described in dma.txt, although they
won't be used, this information is derived from the compatibility string.
Example:
dma: dma-controller@48000000 {
compatible = "renesas,nbpfaxi64dmac8b4";
reg = <0x48000000 0x400>;
interrupts = <0 12 0x4
0 13 0x4
0 14 0x4
0 15 0x4
0 16 0x4
0 17 0x4
0 18 0x4
0 19 0x4>;
#dma-cells = <2>;
dma-channels = <8>;
dma-requests = <8>;
};
* DMA client
Required properties:
dmas and dma-names are required, as described in dma.txt.
Example:
#include <dt-bindings/dma/nbpfaxi.h>
...
dmas = <&dma 0 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)
&dma 1 (NBPF_SLAVE_RQ_HIGH | NBPF_SLAVE_RQ_LEVEL)>;
dma-names = "rx", "tx";