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Update spi_api.c 

Modified line 145:  previously the fill character has been hard coded to 0x00. However in Mbed OS core SPI_FILL_CHAR is defined in the core to be 0xFF by default (one can change that through mbed_app.json for example). This mod allows us to use the same fill character that is defined for Mbed OS.

Also modified spi_master_block_write(): previously it called am_hal_iom_blocking_transfer on line 182, but that prevented succesful SD card writing operations. Now i changed that part to am_hal_iom_spi_blocking_fullduplex and SD functionality seems to be working.
pull/13861/head
Peter B 2020-10-26 16:03:04 +01:00 committed by GitHub
parent c2bddbbc57
commit d56f942ae7
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1 changed files with 8 additions and 4 deletions
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12
targets/TARGET_Ambiq_Micro/TARGET_Apollo3/device/spi_api.c
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@ -142,7 +142,7 @@ void spi_frequency(spi_t *obj, int hz)
int spi_master_write(spi_t *obj, int value)
{
uint32_t rxval = 0;
spi_master_block_write(obj, (const char *)&value, 1, (char *)&rxval, 1, 0x00);
spi_master_block_write(obj, (const char *)&value, 1, (char *)&rxval, 1, SPI_FILL_CHAR);
return rxval;
}
@ -167,7 +167,7 @@ int spi_master_block_write(spi_t *obj, const char *tx_buffer, int tx_length, cha
}
// handle difference between buffers
if (tx_length != rx_length) {
else if (tx_length != rx_length) {
bool Rw = (rx_length >= tx_length);
// set up common config
@ -177,9 +177,13 @@ int spi_master_block_write(spi_t *obj, const char *tx_buffer, int tx_length, cha
xfer.pui32TxBuffer = (Rw) ? NULL : (uint32_t *)(tx_buffer + chars_handled);
uint32_t status = AM_HAL_STATUS_SUCCESS;
if (!Rw || (write_fill == 0x00)) {
if (!Rw || (write_fill == SPI_FILL_CHAR)) {
// when transmitting (w) or reading with a zero fill just use a simplex transfer
status = am_hal_iom_blocking_transfer(obj->spi.iom_obj.iom.handle, &xfer);
uint8_t fill[xfer.ui32NumBytes];
memset(fill, write_fill, xfer.ui32NumBytes);
xfer.eDirection = AM_HAL_IOM_FULLDUPLEX;
xfer.pui32RxBuffer = (uint32_t *)&fill;
uint32_t status = am_hal_iom_spi_blocking_fullduplex(obj->spi.iom_obj.iom.handle, &xfer);
if (AM_HAL_STATUS_SUCCESS != status) {
return chars_handled;
}