diff options
Diffstat (limited to 'src/rp2040')
| -rw-r--r-- | src/rp2040/spi.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/src/rp2040/spi.c b/src/rp2040/spi.c index a92a0358..9303e703 100644 --- a/src/rp2040/spi.c +++ b/src/rp2040/spi.c @@ -128,22 +128,27 @@ spi_prepare(struct spi_config config) ; } +#define MAX_FIFO 8 // Max rx fifo size (don't tx past this size) + void spi_transfer(struct spi_config config, uint8_t receive_data, uint8_t len, uint8_t *data) { - uint8_t* wptr = data; - uint8_t* end = data + len; + uint8_t *wptr = data, *end = data + len; spi_hw_t *spi = config.spi; while (data < end) { uint32_t sr = spi->sr & (SPI_SSPSR_TNF_BITS | SPI_SSPSR_RNE_BITS); - if ((sr == SPI_SSPSR_TNF_BITS) && wptr < end) + if (sr == SPI_SSPSR_TNF_BITS && wptr < end && wptr < data + MAX_FIFO) spi->dr = *wptr++; if (!(sr & SPI_SSPSR_RNE_BITS)) continue; uint8_t rdata = spi->dr; - if(receive_data) + if (receive_data) *data = rdata; data++; } + // Wait for any remaining SCLK updates before returning + while ((spi->sr & (SPI_SSPSR_TFE_BITS|SPI_SSPSR_BSY_BITS)) + != SPI_SSPSR_TFE_BITS) + ; } |