Enum DataDirection

#[repr(u32)]
pub enum DataDirection {
    Bidirectional = 0,
    ToDevice = 1,
    FromDevice = 2,
    None = 3,
}

DMA data direction.

Corresponds to the C enum dma_data_direction.

Variants

Bidirectional = 0

The DMA mapping is for bidirectional data transfer.

This is used when the buffer can be both read from and written to by the device. The cache for the corresponding memory region is both flushed and invalidated.

ToDevice = 1

The DMA mapping is for data transfer from memory to the device (write).

The CPU has prepared data in the buffer, and the device will read it. The cache for the corresponding memory region is flushed before device access.

FromDevice = 2

The DMA mapping is for data transfer from the device to memory (read).

The device will write data into the buffer for the CPU to read. The cache for the corresponding memory region is invalidated before CPU access.

None = 3

The DMA mapping is not for data transfer.

This is primarily for debugging purposes. With this direction, the DMA mapping API will not perform any cache coherency operations.

Trait Implementations

impl Clone for DataDirection

fn clone(&self) -> DataDirection

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DataDirection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<DataDirection> for dma_data_direction

fn from(direction: DataDirection) -> Self

Returns the raw representation of [enum dma_data_direction].

impl PartialEq for DataDirection

fn eq(&self, other: &DataDirection) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for DataDirection

impl Eq for DataDirection

impl StructuralPartialEq for DataDirection