chromeec: Add wakeup delay after SPI /CS assertion
Some ECs may require a few microseconds to ramp up their clock after
being awaken by /CS assertion. This adds a Kconfig variable that can
be overridden at the mainboard-level which will force a delay between
asserting /CS and beginning a transfer.
BUG=chrome-os-partner:32223
BRANCH=none
TEST=verified ~100us delay using logic analyzer
Change-Id: I6d9b8beaa808252f008efb10e7448afdf96d2004
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Original-Commit-Id: ec6b10e4e3f0362dea0dc8046cfd4e4615a42585
Original-Change-Id: Ibba356e4af18f80a7da73c96dadfda0f25251381
Original-Signed-off-by: David Hendricks <dhendrix@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/220242
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-by: Alexandru Stan <amstan@chromium.org>
Reviewed-on: http://review.coreboot.org/9217
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: build bot (Jenkins)
2 files changed