cr50: Add probe command to poll Cr50 until DID VID is valid

Added new routine cr50_i2c_probe() which ensures that communication
with the Cr50 over I2C is good prior to attempting other initialization
of the Cr50 and TPM state.  This avoids a race condition when the Cr50
is first booting that it may reset it's I2C slave interface during the
first few I2C transactions initiated from coreboot.

BUG=b:120009037
BRANCH=none
TEST=Run the Cr50 factory update against Careena board.  Confirm that
I2C reads are retried until the DID VID is valid.  Tested against debug
Cr50 firmware that forced failure of cr50_i2c_probe() and verfied that
coreboot shows recovery screen.

Change-Id: I47c59a32378ad00336277e111e81ba8d2d63e69a
Signed-off-by: Keith Short <keithshort@chromium.org>
Reviewed-on: https://review.coreboot.org/c/30295
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Daniel Kurtz <djkurtz@google.com>

0 files changed, 0 insertions, 0 deletions