soc/amd/common/block/lpc/spi_dma: Implement SPI DMA functionality

This change will make it so the standard rdev readat call will use the
SPI DMA controller if the alignment is correct, and the transfer size is
larger than 64 bytes.

There is a magic bit that needs to be set for the SPI DMA controller to
function correctly. This is only available in RN/CZN+.

BUG=b:179699789
TEST=Boot guybrush to OS. This reduces loading verstage by 40ms,
verifying RW by 500us and loading romstage by 500 us.

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I0be555956581fd82bbe1482d8afa8828c61aaa01
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56228
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

0 files changed, 0 insertions, 0 deletions