SPIDRV - SPI Driver

Description

Serial Peripheral Interface Driver.

The spidrv.c and spidrv.h source files for the SPI driver library are in the emdrv/spidrv folder.


Introduction

The SPI driver supports the SPI capabilities of EFM32/EZR32/EFR32 USARTs. The driver is fully reentrant, supports several driver instances, and does not buffer or queue data. Both synchronous and asynchronous transfer functions are included for both master and slave SPI mode. Synchronous transfer functions are blocking and do not return before the transfer is complete. Asynchronous transfer functions report transfer completion with callback functions. Transfers are handled using DMA.

Note
Transfer completion callback functions are called from within the DMA interrupt handler with interrupts disabled.


Configuration Options

Some properties of the SPIDRV driver are compile-time configurable. These properties are stored in a file named spidrv_config.h. A template for this file, containing default values, is in the emdrv/config folder. Currently the configuration options are as follows:

  • Inclusion of slave API transfer functions.

To configure SPIDRV, provide a custom configuration file. This is a sample spidrv_config.h file:

#ifndef __SILICON_LABS_SPIDRV_CONFIG_H__
#define __SILICON_LABS_SPIDRV_CONFIG_H__

// SPIDRV configuration option. Use this define to include the
// slave part of the SPIDRV API.
#define EMDRV_SPIDRV_INCLUDE_SLAVE

#endif

The properties of each SPI driver instance are set at run-time using the SPIDRV_Init data structure input parameter to the SPIDRV_Init() function.


The API

This section contains brief descriptions of the API functions. For detailed information on input and output parameters and return values, click on the hyperlinked function names. Most functions return an error code, ECODE_EMDRV_SPIDRV_OK is returned on success, see ecode.h and spidrv.h for other error codes.

The application code must include spidrv.h.

SPIDRV_Init(), SPIDRV_DeInit()
These functions initialize or deinitializes the SPIDRV driver. Typically, SPIDRV_Init() is called once in the startup code.

SPIDRV_GetTransferStatus()
Query the status of a transfer. Reports number of items (frames) transmitted and remaining.

SPIDRV_AbortTransfer()
Stop an ongoing transfer.

SPIDRV_SetBitrate(), SPIDRV_GetBitrate()
Set or query the SPI bus bitrate.

SPIDRV_SetFramelength(), SPIDRV_GetFramelength()
Set or query SPI the bus frame length.

SPIDRV_MReceive(), SPIDRV_MReceiveB()
SPIDRV_MTransfer(), SPIDRV_MTransferB(), SPIDRV_MTransferSingleItemB()
SPIDRV_MTransmit(), SPIDRV_MTransmitB()
SPIDRV_SReceive(), SPIDRV_SReceiveB()
SPIDRV_STransfer(), SPIDRV_STransferB()
SPIDRV_STransmit(), SPIDRV_STransmitB()
SPI transfer functions for SPI masters have an uppercase M in their name, the slave counterparts have an S.

As previously mentioned, transfer functions are synchronous and asynchronous. The synchronous versions have an uppercase B (for Blocking) at the end of their function name.

Transmit functions discard received data, receive functions transmit a fixed data pattern set when the driver is initialized (SPIDRV_Init::dummyTxValue). Transfer functions both receive and transmit data.

All slave transfer functions have a millisecond timeout parameter. Use 0 for no (infinite) timeout.


Example

#include "spidrv.h"

SPIDRV_HandleData_t handleData;
SPIDRV_Handle_t handle = &handleData;

void TransferComplete(SPIDRV_Handle_t handle,
                      Ecode_t transferStatus,
                      int itemsTransferred)
{
  if (transferStatus == ECODE_EMDRV_SPIDRV_OK) {
   // Success !
  }
}

int main(void)
{
  uint8_t buffer[10];
  SPIDRV_Init_t initData = SPIDRV_MASTER_USART2;

  // Initialize an SPI driver instance.
  SPIDRV_Init(handle, &initData);

  // Transmit data using a blocking transmit function.
  SPIDRV_MTransmitB(handle, buffer, 10);

  // Transmit data using a callback to catch transfer completion.
  SPIDRV_MTransmit(handle, buffer, 10, TransferComplete);
}

Modules

Error Codes
 
Init Configuration Data
 

Data Structures

struct  SPIDRV_Init
 An SPI driver instance initialization structure.
 
struct  SPIDRV_HandleData
 An SPI driver instance handle data structure.
 

Functions

Ecode_t SPIDRV_AbortTransfer (SPIDRV_Handle_t handle)
 Abort an ongoing SPI transfer.
 
Ecode_t SPIDRV_DeInit (SPIDRV_Handle_t handle)
 Deinitialize an SPI driver instance.
 
Ecode_t SPIDRV_GetBitrate (SPIDRV_Handle_t handle, uint32_t *bitRate)
 Get current SPI bus bitrate.
 
Ecode_t SPIDRV_GetFramelength (SPIDRV_Handle_t handle, uint32_t *frameLength)
 Get current SPI framelength.
 
Ecode_t SPIDRV_GetTransferStatus (SPIDRV_Handle_t handle, int *itemsTransferred, int *itemsRemaining)
 Get the status of an SPI transfer.
 
Ecode_t SPIDRV_Init (SPIDRV_Handle_t handle, SPIDRV_Init_t *initData)
 Initialize an SPI driver instance.
 
Ecode_t SPIDRV_MReceive (SPIDRV_Handle_t handle, void *buffer, int count, SPIDRV_Callback_t callback)
 Start an SPI master receive transfer.
 
Ecode_t SPIDRV_MReceiveB (SPIDRV_Handle_t handle, void *buffer, int count)
 Start an SPI master blocking receive transfer.
 
Ecode_t SPIDRV_MTransfer (SPIDRV_Handle_t handle, const void *txBuffer, void *rxBuffer, int count, SPIDRV_Callback_t callback)
 Start an SPI master transfer.
 
Ecode_t SPIDRV_MTransferB (SPIDRV_Handle_t handle, const void *txBuffer, void *rxBuffer, int count)
 Start an SPI master blocking transfer.
 
Ecode_t SPIDRV_MTransferSingleItemB (SPIDRV_Handle_t handle, uint32_t txValue, void *rxValue)
 Start an SPI master blocking single item (frame) transfer.
 
Ecode_t SPIDRV_MTransmit (SPIDRV_Handle_t handle, const void *buffer, int count, SPIDRV_Callback_t callback)
 Start an SPI master transmit transfer.
 
Ecode_t SPIDRV_MTransmitB (SPIDRV_Handle_t handle, const void *buffer, int count)
 Start an SPI master blocking transmit transfer.
 
Ecode_t SPIDRV_SetBitrate (SPIDRV_Handle_t handle, uint32_t bitRate)
 Set SPI bus bitrate.
 
Ecode_t SPIDRV_SetFramelength (SPIDRV_Handle_t handle, uint32_t frameLength)
 Set SPI framelength.
 
Ecode_t SPIDRV_SReceive (SPIDRV_Handle_t handle, void *buffer, int count, SPIDRV_Callback_t callback, int timeoutMs)
 Start an SPI slave receive transfer.
 
Ecode_t SPIDRV_SReceiveB (SPIDRV_Handle_t handle, void *buffer, int count, int timeoutMs)
 Start an SPI slave blocking receive transfer.
 
Ecode_t SPIDRV_STransfer (SPIDRV_Handle_t handle, const void *txBuffer, void *rxBuffer, int count, SPIDRV_Callback_t callback, int timeoutMs)
 Start an SPI slave transfer.
 
Ecode_t SPIDRV_STransferB (SPIDRV_Handle_t handle, const void *txBuffer, void *rxBuffer, int count, int timeoutMs)
 Start an SPI slave blocking transfer.
 
Ecode_t SPIDRV_STransmit (SPIDRV_Handle_t handle, const void *buffer, int count, SPIDRV_Callback_t callback, int timeoutMs)
 Start an SPI slave transmit transfer.
 
Ecode_t SPIDRV_STransmitB (SPIDRV_Handle_t handle, const void *buffer, int count, int timeoutMs)
 Start an SPI slave blocking transmit transfer.
 

Typedefs

typedef void(* SPIDRV_Callback_t) (struct SPIDRV_HandleData *handle, Ecode_t transferStatus, int itemsTransferred)
 SPIDRV transfer completion callback function.
 
typedef SPIDRV_HandleData_t * SPIDRV_Handle_t
 An SPI driver instance handle.
 

Enumerations

enum  SPIDRV_Type {
  spidrvMaster = 0,
  spidrvSlave = 1
}
 SPI driver instance type.
 
enum  SPIDRV_BitOrder {
  spidrvBitOrderLsbFirst = 0,
  spidrvBitOrderMsbFirst = 1
}
 SPI bus bit order.
 
enum  SPIDRV_ClockMode {
  spidrvClockMode0 = 0,
  spidrvClockMode1 = 1,
  spidrvClockMode2 = 2,
  spidrvClockMode3 = 3
}
 SPI clock mode (clock polarity and phase).
 
enum  SPIDRV_CsControl {
  spidrvCsControlAuto = 0,
  spidrvCsControlApplication = 1
}
 SPI master chip select (CS) control scheme.
 
enum  SPIDRV_SlaveStart {
  spidrvSlaveStartImmediate = 0,
  spidrvSlaveStartDelayed = 1
}
 SPI slave transfer start scheme.
 

Function Documentation

◆ SPIDRV_AbortTransfer()

Ecode_t SPIDRV_AbortTransfer ( SPIDRV_Handle_t  handle)

Abort an ongoing SPI transfer.

Parameters
[in]handlePointer to an SPI driver handle.
Returns
ECODE_EMDRV_SPIDRV_OK on success, ECODE_EMDRV_SPIDRV_IDLE if SPI is idle. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_DeInit()

Ecode_t SPIDRV_DeInit ( SPIDRV_Handle_t  handle)

Deinitialize an SPI driver instance.

Warning
This function should only be called with an initialized spidrv instance handle.
Parameters
[in]handlePointer to an SPI driver handle.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_GetBitrate()

Ecode_t SPIDRV_GetBitrate ( SPIDRV_Handle_t  handle,
uint32_t *  bitRate 
)

Get current SPI bus bitrate.

Parameters
[in]handlePointer to an SPI driver handle.
[out]bitRateCurrent SPI bus bitrate.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_GetFramelength()

Ecode_t SPIDRV_GetFramelength ( SPIDRV_Handle_t  handle,
uint32_t *  frameLength 
)

Get current SPI framelength.

Parameters
[in]handlePointer to an SPI driver handle.
[out]frameLengthCurrent SPI bus framelength.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_GetTransferStatus()

Ecode_t SPIDRV_GetTransferStatus ( SPIDRV_Handle_t  handle,
int *  itemsTransferred,
int *  itemsRemaining 
)

Get the status of an SPI transfer.

Returns status of an ongoing transfer. If no transfer is in progress, the status of the last transfer is reported.

Parameters
[in]handlePointer to an SPI driver handle.
[out]itemsTransferredNumber of items (frames) transferred.
[out]itemsRemainingNumber of items (frames) remaining.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_Init()

Ecode_t SPIDRV_Init ( SPIDRV_Handle_t  handle,
SPIDRV_Init_t *  initData 
)

Initialize an SPI driver instance.

Parameters
[out]handlePointer to an SPI driver handle; refer to SPIDRV_Handle_t.
[in]initDataPointer to an initialization data structure; refer to SPIDRV_Init.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MReceive()

Ecode_t SPIDRV_MReceive ( SPIDRV_Handle_t  handle,
void *  buffer,
int  count,
SPIDRV_Callback_t  callback 
)

Start an SPI master receive transfer.

Note
The MOSI wire will transmit SPIDRV_Init::dummyTxValue.
Parameters
[in]handlePointer to an SPI driver handle.
[out]bufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MReceiveB()

Ecode_t SPIDRV_MReceiveB ( SPIDRV_Handle_t  handle,
void *  buffer,
int  count 
)

Start an SPI master blocking receive transfer.

Note
The MOSI wire will transmit SPIDRV_Init::dummyTxValue.
This function is blocking and returns when the transfer is complete or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[out]bufferReceive data buffer.
[in]countNumber of bytes in transfer.
Returns
ECODE_EMDRV_SPIDRV_OK on success or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MTransfer()

Ecode_t SPIDRV_MTransfer ( SPIDRV_Handle_t  handle,
const void *  txBuffer,
void *  rxBuffer,
int  count,
SPIDRV_Callback_t  callback 
)

Start an SPI master transfer.

Parameters
[in]handlePointer to an SPI driver handle.
[in]txBufferTransmit data buffer.
[out]rxBufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MTransferB()

Ecode_t SPIDRV_MTransferB ( SPIDRV_Handle_t  handle,
const void *  txBuffer,
void *  rxBuffer,
int  count 
)

Start an SPI master blocking transfer.

Note
This function is blocking and returns when the transfer is complete or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[in]txBufferTransmit data buffer.
[out]rxBufferReceive data buffer.
[in]countNumber of bytes in transfer.
Returns
ECODE_EMDRV_SPIDRV_OK on success or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MTransferSingleItemB()

Ecode_t SPIDRV_MTransferSingleItemB ( SPIDRV_Handle_t  handle,
uint32_t  txValue,
void *  rxValue 
)

Start an SPI master blocking single item (frame) transfer.

Note
This function is blocking and returns when the transfer is complete or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[in]txValueValue to transmit.
[out]rxValueValue received.
Returns
ECODE_EMDRV_SPIDRV_OK on success or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MTransmit()

Ecode_t SPIDRV_MTransmit ( SPIDRV_Handle_t  handle,
const void *  buffer,
int  count,
SPIDRV_Callback_t  callback 
)

Start an SPI master transmit transfer.

Note
The data received on the MISO wire is discarded.
Parameters
[in]handlePointer to an SPI driver handle.
[in]bufferTransmit data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_MTransmitB()

Ecode_t SPIDRV_MTransmitB ( SPIDRV_Handle_t  handle,
const void *  buffer,
int  count 
)

Start an SPI master blocking transmit transfer.

Note
The data received on the MISO wire is discarded.
This function is blocking and returns when the transfer is complete.
Parameters
[in]handlePointer to an SPI driver handle.
[in]bufferTransmit data buffer.
[in]countNumber of bytes in transfer.
Returns
ECODE_EMDRV_SPIDRV_OK on success or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_SetBitrate()

Ecode_t SPIDRV_SetBitrate ( SPIDRV_Handle_t  handle,
uint32_t  bitRate 
)

Set SPI bus bitrate.

Parameters
[in]handlePointer to an SPI driver handle.
[in]bitRateNew SPI bus bitrate.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_SetFramelength()

Ecode_t SPIDRV_SetFramelength ( SPIDRV_Handle_t  handle,
uint32_t  frameLength 
)

Set SPI framelength.

Parameters
[in]handlePointer to an SPI driver handle.
[in]frameLengthNew SPI bus framelength.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_SReceive()

Ecode_t SPIDRV_SReceive ( SPIDRV_Handle_t  handle,
void *  buffer,
int  count,
SPIDRV_Callback_t  callback,
int  timeoutMs 
)

Start an SPI slave receive transfer.

Note
The MISO wire will transmit SPIDRV_Init::dummyTxValue.
Parameters
[in]handlePointer to an SPI driver handle.
[out]bufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_SReceiveB()

Ecode_t SPIDRV_SReceiveB ( SPIDRV_Handle_t  handle,
void *  buffer,
int  count,
int  timeoutMs 
)

Start an SPI slave blocking receive transfer.

Note
The MISO wire will transmit SPIDRV_Init::dummyTxValue.
This function is blocking and returns when the transfer is complete, on timeout, or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[out]bufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success, ECODE_EMDRV_SPIDRV_TIMEOUT on timeout or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_STransfer()

Ecode_t SPIDRV_STransfer ( SPIDRV_Handle_t  handle,
const void *  txBuffer,
void *  rxBuffer,
int  count,
SPIDRV_Callback_t  callback,
int  timeoutMs 
)

Start an SPI slave transfer.

Parameters
[in]handlePointer to an SPI driver handle.
[in]txBufferTransmit data buffer.
[out]rxBufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_STransferB()

Ecode_t SPIDRV_STransferB ( SPIDRV_Handle_t  handle,
const void *  txBuffer,
void *  rxBuffer,
int  count,
int  timeoutMs 
)

Start an SPI slave blocking transfer.

Note

This function is blocking and returns when the transfer is complete, on timeout, or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[in]txBufferTransmit data buffer.
[out]rxBufferReceive data buffer.
[in]countNumber of bytes in transfer.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success, ECODE_EMDRV_SPIDRV_TIMEOUT on timeout or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_STransmit()

Ecode_t SPIDRV_STransmit ( SPIDRV_Handle_t  handle,
const void *  buffer,
int  count,
SPIDRV_Callback_t  callback,
int  timeoutMs 
)

Start an SPI slave transmit transfer.

Note
The data received on the MOSI wire is discarded.
Parameters
[in]handlePointer to an SPI driver handle.
[in]bufferTransmit data buffer.
[in]countNumber of bytes in transfer.
[in]callbackTransfer completion callback.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success. On failure, an appropriate SPIDRV Ecode_t is returned.

◆ SPIDRV_STransmitB()

Ecode_t SPIDRV_STransmitB ( SPIDRV_Handle_t  handle,
const void *  buffer,
int  count,
int  timeoutMs 
)

Start an SPI slave blocking transmit transfer.

Note
The data received on the MOSI wire is discarded.
This function is blocking and returns when the transfer is complete, on timeout, or when SPIDRV_AbortTransfer() is called.
Parameters
[in]handlePointer to an SPI driver handle.
[in]bufferTransmit data buffer.
[in]countNumber of bytes in transfer.
[in]timeoutMsTransfer timeout in milliseconds.
Returns
ECODE_EMDRV_SPIDRV_OK on success, ECODE_EMDRV_SPIDRV_TIMEOUT on timeout or ECODE_EMDRV_SPIDRV_ABORTED if SPIDRV_AbortTransfer() has been called. On failure, an appropriate SPIDRV Ecode_t is returned.

Typedef Documentation

◆ SPIDRV_Callback_t

typedef void(* SPIDRV_Callback_t) (struct SPIDRV_HandleData *handle, Ecode_t transferStatus, int itemsTransferred)

SPIDRV transfer completion callback function.

Called when a transfer is complete. An application should check the transferStatus and itemsTransferred values.

Parameters
[in]handleThe SPIDRV device handle used to start the transfer.
[in]transferStatusA number of bytes actually transferred.
[in]itemsTransferredA number of bytes transferred.
Returns
ECODE_EMDRV_SPIDRV_OK on success, ECODE_EMDRV_SPIDRV_TIMEOUT on timeout. Timeouts are only relevant for slave mode transfers.

◆ SPIDRV_Handle_t

typedef SPIDRV_HandleData_t* SPIDRV_Handle_t

An SPI driver instance handle.

Enumeration Type Documentation

◆ SPIDRV_Type

SPI driver instance type.

Enumerator
spidrvMaster 

Act as an SPI master.

spidrvSlave 

Act as an SPI slave.

◆ SPIDRV_BitOrder

SPI bus bit order.

Enumerator
spidrvBitOrderLsbFirst 

LSB bit is transmitted first.

spidrvBitOrderMsbFirst 

MSB bit is transmitted first.

◆ SPIDRV_ClockMode

SPI clock mode (clock polarity and phase).

Enumerator
spidrvClockMode0 

SPI mode 0: CLKPOL=0, CLKPHA=0.

spidrvClockMode1 

SPI mode 1: CLKPOL=0, CLKPHA=1.

spidrvClockMode2 

SPI mode 2: CLKPOL=1, CLKPHA=0.

spidrvClockMode3 

SPI mode 3: CLKPOL=1, CLKPHA=1.

◆ SPIDRV_CsControl

SPI master chip select (CS) control scheme.

Enumerator
spidrvCsControlAuto 

CS controlled by the SPI driver.

spidrvCsControlApplication 

CS controlled by the application.

◆ SPIDRV_SlaveStart

SPI slave transfer start scheme.

Enumerator
spidrvSlaveStartImmediate 

Transfer starts immediately.

spidrvSlaveStartDelayed 

Transfer starts when the bus is idle (CS deasserted).