andestech,atcdmac300

Vendor: Andes Technology Corporation

Description

These nodes are “dma” bus nodes.

Andes DMA controller
channel: a phandle to the DMA controller plus the following four integer cells:
  1. channel: the dma channel
  2. slot: DMA peripheral request ID
  3. channel-config: A 32bit mask specifying the DMA channel configuration
  which is device dependent:
      -bit 0-1 : Direction  (see dma.h)
             0x0: MEM to MEM
             0x1: MEM to PERIPH
             0x2: PERIPH to MEM
             0x3: reserved for PERIPH to PERIPH
      -bit 2 : Peripheral Increment Address
             0x0: no address increment between transfers
             0x1: increment address between transfers
      -bit 3 : Memory Increment Address
             0x0: no address increment between transfers
             0x1: increment address between transfers
      -bit 4-6 : Peripheral data size
             0x0: Byte (8 bits)
             0x1: Half-word (16 bits)
             0x2: Word (32 bits)
             0x3: Double word (64 bits)
             0x4: Quad word (128 bits)
             0x5: Eight word (256 bits)
             0x6-0x7: reserved
      -bit 7-9 : Memory data size
             0x0: Byte (8 bits)
             0x1: Half-word (16 bits)
             0x2: Word (32 bits)
             0x3: Double word (64 bits)
             0x4: Quad word (128 bits)
             0x5: Eight word (256 bits)
             0x6-0x7: reserved
      -bit 10 : Priority level
             0x0: lower priority
             0x1: higher priority

  examples for andes_v5_ae350 DMA instance
   dma0: dma0@f0c00000 {
       compatible = "andestech,atcdmac300";
       ...
       dma-channels = <8>;
       dma-requests = <16>;
       status = "disabled";
       label = "DMA_0";
      };

For the client part, example for andes_ae350 DMA instance
  Tx using channel 2, slot 0
  Rx using channel 3, slot 1
  spi1: spi@f0f00000 {
   compatible = "andestech,atcspi200"
   dmas = <&dma0 2 0 0x0129>,
          <&dma0 3 1 0x012A>;
   dma-names = "tx", "rx";
   };

Properties

Properties not inherited from the base binding file.

Name

Type

Details

#dma-cells

int

Number of items to expect in a DMA specifier

This property is required.

Constant value: 3

dma-channel-mask

int

Bitmask of available DMA channels in ascending order that are
not reserved by firmware and are available to the
kernel. i.e. first channel corresponds to LSB.

dma-channels

int

Number of DMA channels supported by the controller

dma-requests

int

Number of DMA request signals supported by the controller.

dma-buf-addr-alignment

int

Memory address alignment requirement for DMA buffers used by the controller.

dma-buf-size-alignment

int

Memory size alignment requirement for DMA buffers used by the controller.

dma-copy-alignment

int

Minimal chunk of data possible to be copied by the controller.

chain-transfer

int

Specifier cell names

  • dma cells: channel, slot, channel-config