st,stm32-dma

Vendor: STMicroelectronics

Description

These nodes are “dma” bus nodes.

STM32 DMA controller

The STM32 DMA is a general-purpose direct memory access controller
capable of supporting 5 or 6 or 7 or 8 independent DMA channels.
Each stm32 soc with a DMA is of a special version type, which could be
V1 like stm32F4 or stm32F2 socs, they include FIFO control registers
or V2 like stm32L4 soc or stm322WB, some also have DMAMUX controller
or V2bis like stm32F1 or stm32L1, where requests are multiplexed

Properties

Properties not inherited from the base binding file.

Name

Type

Details

st,mem2mem

boolean

If the DMA controller V1 supports memory to memory transfer

dma-offset

int

offset in the table of channels when mapping to a DMAMUX
for 1st dma instance, offset is 0,
for 2nd dma instance, offset is the nb of dma channels of the 1st dma,
for 3rd dma instance, offset is the nb of dma channels of the 2nd dma
plus the nb of dma channels of the 1st dma instance, etc.

#dma-cells

int

Number of items to expect in a DMA specifier

This property is required.

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.