linux_dsm_epyc7002/Documentation/devicetree/bindings/dma/ste-dma40.txt
Lee Jones 0a05ef0ec1 dma: ste_dma40: Expand DT binding to accept 'high-priority channel' flag
This is used for MSP (audio) devices which is about to be fully DT:ed.

Cc: devicetree@vger.kernel.org
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-11-26 21:01:58 +01:00

70 lines
2.1 KiB
Plaintext

* DMA40 DMA Controller
Required properties:
- compatible: "stericsson,dma40"
- reg: Address range of the DMAC registers
- reg-names: Names of the above areas to use during resource look-up
- interrupt: Should contain the DMAC interrupt number
- #dma-cells: must be <3>
- memcpy-channels: Channels to be used for memcpy
Optional properties:
- dma-channels: Number of channels supported by hardware - if not present
the driver will attempt to obtain the information from H/W
- disabled-channels: Channels which can not be used
Example:
dma: dma-controller@801C0000 {
compatible = "stericsson,db8500-dma40", "stericsson,dma40";
reg = <0x801C0000 0x1000 0x40010000 0x800>;
reg-names = "base", "lcpa";
interrupt-parent = <&intc>;
interrupts = <0 25 0x4>;
#dma-cells = <2>;
memcpy-channels = <56 57 58 59 60>;
disabled-channels = <12>;
dma-channels = <8>;
};
Clients
Required properties:
- dmas: Comma separated list of dma channel requests
- dma-names: Names of the aforementioned requested channels
Each dmas request consists of 4 cells:
1. A phandle pointing to the DMA controller
2. Device Type
3. The DMA request line number (only when 'use fixed channel' is set)
4. A 32bit mask specifying; mode, direction and endianness [NB: This list will grow]
0x00000001: Mode:
Logical channel when unset
Physical channel when set
0x00000002: Direction:
Memory to Device when unset
Device to Memory when set
0x00000004: Endianness:
Little endian when unset
Big endian when set
0x00000008: Use fixed channel:
Use automatic channel selection when unset
Use DMA request line number when set
0x00000010: Set channel as high priority:
Normal priority when unset
High priority when set
Example:
uart@80120000 {
compatible = "arm,pl011", "arm,primecell";
reg = <0x80120000 0x1000>;
interrupts = <0 11 0x4>;
dmas = <&dma 13 0 0x2>, /* Logical - DevToMem */
<&dma 13 0 0x0>; /* Logical - MemToDev */
dma-names = "rx", "rx";
status = "disabled";
};