spi: dt-bindings: introduce FIFO depth properties

There are SPI IPs that can be configured by the integrator with a
specific FIFO depth depending on the system's capabilities. For example,
the samsung USI SPI IP can be configured by the integrator with a TX/RX
FIFO from 8 byte to 256 bytes.

Introduce the ``fifo-depth`` property for such instances of IPs where the
same FIFO depth is used for both RX and TX. Introduce ``rx-fifo-depth``
and ``tx-fifo-depth`` properties for cases where the RX FIFO depth is
different from the TX FIFO depth.

Make the dedicated RX/TX properties dependent on each other and mutual
exclusive with the other.

Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Tudor Ambarus <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://msgid.link/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>

0 files changed, 0 insertions, 0 deletions