/*****************************************************************************
* @fn HalUARTReadSPI
*
* @brief Execute a blocking read from master if Rx buffer is empty. Otherwise return up to 'len'
* bytes of read data.
*
* @param buf - valid data buffer at least 'len' bytes in size
* len - max length number of bytes to copy to 'buf'
*
* @return length of buffer that was read
*****************************************************************************/
uint16 HalUARTReadSPI(uint8 *buf, uint16 len)
{
uint16 cnt = 0;
if ((spiCfg.rxHead == 0) && (spiCfg.rxHead == spiCfg.rxTail))
{
uint8 tmp;
UxDBUF = 0;
URXxIF = 0;
// Slave signals ready for read by setting its ready flag first.
SRDY_SET();
while (!MRDY_SET);
do {
while (!URXxIF && MRDY_SET);
tmp = UxDBUF;
URXxIF = 0;
// Master ends slave read by clearing its ready flag first.
if (!MRDY_SET)
{
break;
}
spiCfg.rxBuf[spiCfg.rxTail] = tmp;
if (++spiCfg.rxTail >= HAL_UART_SPI_RX_MAX)
{
spiCfg.rxTail = 0;
}
} while(1);
// Master blocks waiting for slave to clear its ready flag before continuing.
SRDY_CLR();
}
while ((spiCfg.rxHead != spiCfg.rxTail) && (cnt < len))
{
*buf++ = spiCfg.rxBuf[spiCfg.rxHead++];
if (spiCfg.rxHead >= HAL_UART_SPI_RX_MAX)
{
spiCfg.rxHead = 0;
}
cnt++;
}
if (cnt == 0)
{
spiCfg.rxHead = spiCfg.rxTail = 0;
}
return cnt;
}
/******************************************************************************
* @fn HalUARTWriteSPI
*
* @brief Write a buffer to the UART.
* @brief Execute a blocking write to the master.
*
* @param buf - pointer to the buffer that will be written, not freed
* len - length of
*
* @return length of the buffer that was sent
*****************************************************************************/
uint16 HalUARTWriteSPI(uint8 *buf, uint16 len)
{
uint16 cnt;
// Enforce all or none and at least one.
if ((HAL_UART_SPI_TX_AVAIL() < len) || (len == 0))
{
return 0;
}
UxDBUF = *buf++;
for (cnt = 1; cnt < len; cnt++)
{
spiCfg.txBuf[spiCfg.txTail] = *buf++;
if (spiCfg.txTail >= HAL_UART_SPI_TX_MAX-1)
{
spiCfg.txTail = 0;
}
else
{
spiCfg.txTail++;
}
}
URXxIF = 0;
// Master signals ready for slave write by setting its ready flag first.
while (!MRDY_SET);
// Master blocks waiting for slave to set its ready flag before continuing.
SRDY_SET();
do {
while (!URXxIF && MRDY_SET);
UxDBUF = spiCfg.txBuf[spiCfg.txHead];
URXxIF = 0;
if (spiCfg.txHead == spiCfg.txTail)
{
spiCfg.txBuf[spiCfg.txHead] = 0;
}
else if (++spiCfg.txHead >= HAL_UART_SPI_TX_MAX)
{
spiCfg.txHead = 0;
}
} while(MRDY_SET); // Master ends slave write by clearing its ready flag first.
// Master blocks waiting for slave to set its ready flag before continuing.
SRDY_CLR();
return cnt;
}
/**************************************************************************************************
* @fn sblWait
*
* @brief A timed-out wait loop that exits early upon receiving a force code/sbl byte.
*
* input parameters
*
* None.
*
* output parameters
*
* None.
*
* @return TRUE to run the code image, FALSE to run the SBL.
**************************************************************************************************
*/
static uint8 sblWait(uint16 sbl_wait_time)
{
uint32 dlyCnt;
uint8 rtrn = FALSE;
uint8 sbExec_rc;
uint8 ch;
if (znpCfg1 == ZNP_CFG1_SPI)
{
// Slave signals ready for read by setting its ready flag first.
SRDY_SET();
// Flag to sbRx() to poll for 1 Rx byte instead of blocking read until MRDY_CLR.
spiPoll = TRUE;
dlyCnt = 0x38; // About 50 msecs.
}
else
{
URX0IE = 1;
HAL_ENABLE_INTERRUPTS();
dlyCnt = (uint32)0x7332 * sbl_wait_time; //0x7332 gives about 1 second
sbReportState(SB_STATE_WAITING);
}
while (1)
{
if (znpCfg1 == ZNP_CFG1_UART)
{
sbUartPoll();
sbExec_rc = sbExec();
if (sbExec_rc == SB_CMND_ENABLE_STATE_REPORTING)
{
sbReportState(SB_STATE_WAITING);
}
else if (sbExec_rc == SB_CMND_FORCE_RUN)
{
dlyCnt = 0;
}
else if ((sbExec_rc != SB_CMND_IDLE) && (sbExec_rc != SB_CMND_UNSUPPORTED))
{
break;
}
}
else // Note: the SPI implementation was left unchanged, since the new implementation
// (as implemented for the UART) was not tested with SPI at this time.
{
if (sbRx(&ch, 1))
{
if (ch == SB_FORCE_BOOT)
{
break;
}
else if (ch == SB_FORCE_RUN)
{
dlyCnt = 0;
}
}
}
if (dlyCnt-- == 0)
{
rtrn = TRUE;
break;
}
}
if (znpCfg1 == ZNP_CFG1_SPI)
{
// Master blocks waiting for slave to clear its ready flag before continuing.
SRDY_CLR();
// Flag to sbRx() to now block while reading Rx bytes until MRDY_CLR.
spiPoll = FALSE;
}
else
{
HAL_DISABLE_INTERRUPTS();
URX0IE = 0;
}
return rtrn;
}
