Quite often, you only want to do a single SPI transfer with chip select toggling before and after. Add a simple convenience wrapper for this purpose. For more "advanced" usage, the spi_xfer() function is still available.
Signed-off-by: Haavard Skinnemoen haavard.skinnemoen@atmel.com --- include/spi.h | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/include/spi.h b/include/spi.h index 320e50e..be87173 100644 --- a/include/spi.h +++ b/include/spi.h @@ -176,6 +176,19 @@ void spi_cs_activate(struct spi_slave *slave); void spi_cs_deactivate(struct spi_slave *slave);
/*----------------------------------------------------------------------- + * Single SPI Transfer + * + * Convenience wrapper for doing a single SPI transfer, i.e. asserting + * CS before, and deasserting it after the transfer. + */ +static inline int spi_xfer_single(struct spi_slave *slave, + unsigned int bitlen, const void *dout, void *din) +{ + return spi_xfer(slave, bitlen, dout, din, + SPI_XFER_BEGIN | SPI_XFER_END); +} + +/*----------------------------------------------------------------------- * Write 8 bits, then read 8 bits. * slave: The SPI slave we're communicating with * byte: Byte to be written @@ -193,7 +206,7 @@ static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte) dout[0] = byte; dout[1] = 0;
- ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END); + ret = spi_xfer_single(slave, 16, dout, din); return ret < 0 ? ret : din[1]; }