Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line
might be missing from an ADC while for a DAC the MISO/RX line may be
optional. This patch adds these two new modes: SPI_NO_TX and
SPI_NO_RX. This way, the drivers will be able to identify if any of
these two lines is missing and to adjust the transfers accordingly.
Signed-off-by: NDragos Bogdan <dragos.bogdan@analog.com>
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.comSigned-off-by: NMark Brown <broonie@kernel.org>