Vincent Palatin 23ea0c9fa3 spi: extend spi master API on STM32 ...

Extend the SPI master API to be able to do fancier transactions:
- allow to read the incoming bits while transmitting.
If SPI_READBACK_ALL is set in 'rxlen' when calling spi_transaction(),
then the received data during transmission is recorded in rxdata buffer
and the function assumes that the real 'rxlen' is equal to 'txlen'.
- add spi_transaction_wait() which is similar to spi_transaction_flush()
but without de-asserting the chip select, so we can chain several
transfers in a single transaction.

Implement them for STM32.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=b:35648259
TEST=on Eve, use the FP sensor with the passthru.

Change-Id: Iebff617acd3230277d36a4f565766b7748721a1d
Reviewed-on: https://chromium-review.googlesource.com/452898
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>

2017-03-13 17:53:58 -07:00

3.2 KiB

Raw Blame History

View Raw