pub trait SpiSlave {
fn init(&self) -> Result<(), ErrorCode>;
fn has_client(&self) -> bool;
fn set_client(&self, client: Option<&'static dyn SpiSlaveClient>);
fn set_write_byte(&self, write_byte: u8);
fn read_write_bytes(
&self,
write_buffer: Option<&'static mut [u8]>,
read_buffer: Option<&'static mut [u8]>,
len: usize
) -> Result<(), (ErrorCode, Option<&'static mut [u8]>, Option<&'static mut [u8]>)>;
fn set_polarity(&self, polarity: ClockPolarity) -> Result<(), ErrorCode>;
fn get_polarity(&self) -> ClockPolarity;
fn set_phase(&self, phase: ClockPhase) -> Result<(), ErrorCode>;
fn get_phase(&self) -> ClockPhase;
}
Expand description
Trait for SPI peripherals (slaves) to exchange data with a contoller
(master). This is a low-level trait typically implemented by hardware:
higher level software typically uses the SpiSlaveDevice
trait,
which is provided by a virtualizing/multiplexing layer.
Required Methods
Initialize the SPI device to be in peripheral mode. Return values:
- Ok(()): the device is in peripheral mode
- Err(BUSY): the device is busy with an operation and cannot be initialized
- Err(FAIL): other failure condition
fn has_client(&self) -> bool
fn has_client(&self) -> bool
Returns true if there is a client. Useful for verifying that two software drivers do not both try to take control of the device.
fn set_client(&self, client: Option<&'static dyn SpiSlaveClient>)
fn set_client(&self, client: Option<&'static dyn SpiSlaveClient>)
Set the callback for slave operations, passing None
to
disable peripheral mode.
fn set_write_byte(&self, write_byte: u8)
fn set_write_byte(&self, write_byte: u8)
Set a single byte to write in response to a read/write operation from a controller. Useful for devices that always send a status code in their first byte.
Provide buffers for the peripheral to write from and read
into when a controller performs a read_write_bytes
operation.
The device will issue a callback when one of four things occurs:
- The controller completes the operation by bringing the chip select high.
- A
Some
write buffer is written. - A
Some
read buffer is filled. len
bytes are read/written Return values:- Ok(()): the SPI bus will read/write the provided buffers on the next SPI operation requested by the controller.
- Err(BUSY): the device is busy with an existing
read_write_bytes
operation. - Err(INVAL): the
len
parameter is 0
Err
return values return the passed buffer Option
s.
fn set_polarity(&self, polarity: ClockPolarity) -> Result<(), ErrorCode>
fn set_polarity(&self, polarity: ClockPolarity) -> Result<(), ErrorCode>
Set the bus polarity (whether idle is high or low). Return values:
- Ok(()): the polarity was set.
- Err(BUSY): the SPI bus is busy with a
read_write_bytes
operation whose callback hasn’t been called yet. - Err(FAIL): other failure
fn get_polarity(&self) -> ClockPolarity
fn get_polarity(&self) -> ClockPolarity
Return the current bus polarity.
Set the bus phase (whether data is sent/received on leading or trailing edges).
- Ok(()): the phase was set.
- Err(BUSY): the SPI bus is busy with a
read_write_bytes
operation whose callback hasn’t been called yet. - Err(FAIL): other failure
fn get_phase(&self) -> ClockPhase
fn get_phase(&self) -> ClockPhase
Return the current bus phase.