File content as of revision 72:35ea0b4e725b:

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/*!
 ******************************************************************************
 * @file:
 * @brief:  ADMW OS-dependent wrapper layer for SPI interface
 *-----------------------------------------------------------------------------
 */

#include <mbed.h>

#include "inc/admw_spi.h"
#include "inc/admw_log.h"

#define ADMW_SPI_MODE       0 /* CPOL=0, CPHA=0 */
#define ADMW_SPI_FRAME_SIZE 8 /* 8-bit frame size */


#ifdef __cplusplus
extern "C" {
#endif


// Struct to contain anything needed to identify the SPI device
// This is returned as a ADMW_SPI_HANDLE*, and is required to use
// the other SPI functions
typedef struct {
    SPI *_spi;
    DigitalOut *_cs;
    DigitalOut *_wakeup;
} SpiContext_t;


/*
 * Open the SPI interface and allocate resources
 */
ADMW_RESULT admw_SpiOpen(
    ADMW_PLATFORM_SPI_CONFIG *pConfig,
    ADMW_SPI_HANDLE *phDevice)
{
    SpiContext_t *pCtx = (SpiContext_t*)malloc(sizeof(*pCtx));
    if(!pCtx) {
        ADMW_LOG_ERROR("Failed to allocate memory for SPI device");
        return ADMW_NO_MEM;
    }
    
    pCtx->_spi = new SPI((PinName)pConfig->mosiPin,
                (PinName)pConfig->misoPin,
                (PinName)pConfig->sckPin);
    pCtx->_cs = new DigitalOut((PinName)pConfig->csPin, 1);
    
    pCtx->_spi->format(ADMW_SPI_FRAME_SIZE, ADMW_SPI_MODE);
    pCtx->_spi->frequency(pConfig->maxSpeedHz);
    
    pCtx->_wakeup = new DigitalOut((PinName)pConfig->wakeupPin, 1);
    
    *phDevice = (ADMW_SPI_HANDLE)pCtx;
    
    return ADMW_SUCCESS;
}

ADMW_RESULT
admw_SpiReceive(
    ADMW_SPI_HANDLE hDevice,
    void *pTxData,
    void *pRxData,
    unsigned nLength,
    bool bCsHold)
{
    SpiContext_t *pCtx = (SpiContext_t*)hDevice;
    
    pCtx->_spi->format(ADMW_SPI_FRAME_SIZE, 1);
    
    int rc = 0;
   
    *(pCtx->_wakeup) = 1;
    wait_us(31);
    *(pCtx->_cs) = 0;
     
    rc  = pCtx->_spi->write((char*)(pTxData), pTxData ? nLength : 0,
                     (char*)(pRxData), pRxData ? nLength : 0);
    
    if ((rc < 0) || !bCsHold)
    {
       *(pCtx->_cs) = 1;
    }
    *(pCtx->_wakeup) = 0;
       
    if (rc < 0)
    {
        ADMW_LOG_ERROR("Failed to complete SPI transfer");
        return ADMW_FAILURE;
    }
    
    pCtx->_spi->format(ADMW_SPI_FRAME_SIZE, ADMW_SPI_MODE);
    
    return ADMW_SUCCESS;
}

/*
 * Execute a bi-directional data transfer on the SPI interface
 */
ADMW_RESULT
admw_SpiTransfer(
    ADMW_SPI_HANDLE hDevice,
    void *pTxData,
    void *pRxData,
    unsigned nLength,
    bool bCsHold)
{
    int rc = 0;
    
    SpiContext_t *pCtx = (SpiContext_t*)hDevice;

    *(pCtx->_wakeup) = 1;
    wait_us(31);
    *(pCtx->_cs) = 0;
    *(pCtx->_wakeup) = 0;
    rc  = pCtx->_spi->write((char*)(pTxData), pTxData ? nLength : 0,
                     (char*)(pRxData), pRxData ? nLength : 0);
    
    if ((rc < 0) || !bCsHold)
        *(pCtx->_cs) = 1;

    if (rc < 0)
    {
        ADMW_LOG_ERROR("Failed to complete SPI transfer");
        return ADMW_FAILURE;
    }
    
    return ADMW_SUCCESS;
}

/*
 * Close the SPI interface and free resources
 */
void admw_SpiClose(
    ADMW_SPI_HANDLE hDevice)
{
    SpiContext_t *pCtx = (SpiContext_t *)hDevice;

    delete pCtx->_spi;
    delete pCtx->_cs;
    delete pCtx->_wakeup;
    
    free(pCtx);
}

#ifdef __cplusplus
}
#endif

/*!
 * @}
 */