diff options
Diffstat (limited to 'drivers/spi/soft_spi.c')
| -rw-r--r-- | drivers/spi/soft_spi.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c index 5d22351..c969be3 100644 --- a/drivers/spi/soft_spi.c +++ b/drivers/spi/soft_spi.c @@ -136,10 +136,14 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, /* * Check if it is time to work on a new byte. */ - if((j % 8) == 0) { - tmpdout = *txd++; + if ((j % 8) == 0) { + if (txd) + tmpdout = *txd++; + else + tmpdout = 0; if(j != 0) { - *rxd++ = tmpdin; + if (rxd) + *rxd++ = tmpdin; } tmpdin = 0; } @@ -164,9 +168,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, * bits over to left-justify them. Then store the last byte * read in. */ - if((bitlen % 8) != 0) - tmpdin <<= 8 - (bitlen % 8); - *rxd++ = tmpdin; + if (rxd) { + if ((bitlen % 8) != 0) + tmpdin <<= 8 - (bitlen % 8); + *rxd++ = tmpdin; + } if (flags & SPI_XFER_END) spi_cs_deactivate(slave); |