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| author | Alec Berg <alecaberg@chromium.org> | 2014-04-26 11:51:23 -0700 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-04-29 03:11:12 +0000 |
| commit | b57137dcac703ef9428032332ddff470ab424906 (patch) | |
| tree | b607e50db02155de643d5f38059f376b81f54a49 /include/ec_commands.h | |
| parent | 6f21e3f5c1c61caac1535ec433210aac213c1c1c (diff) | |
| download | chrome-ec-b57137dcac703ef9428032332ddff470ab424906.tar.gz | |
stm32: pd: add config option to use SPI master for USB PD trasmit
Added config option CONFIG_USB_PD_TX_USES_SPI_MASTER which switches
to use SPI master for PD transmit. The advantage of SPI master mode
is at the end of the tranmission, we don't have to send any dummy 0
bits. When the option is set, the CPU_CLOCK must be set to 38.4MHz,
so that the SPI master can generate the correct clock frequency.
BUG=chrome-os-partner:28309
BRANCH=none
TEST=Tested by connecting two fruitpies together across CC1. One
fruitpie has been modified such that the MISO and MOSI lines are
swapped and is running PD TX in SPI master mode with 38.4MHz clock,
while the other is running PD TX in SPI slave mode. On EC console
ran pd charger on one board and pd dev on other board. Verified
that communication works with no errors. Ran for 10 minutes in each
configuration.
Change-Id: Ib24030d34d95d59f4ac6c2dae98bf7adda1ada01
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/197215
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Diffstat (limited to 'include/ec_commands.h')
0 files changed, 0 insertions, 0 deletions