realtek_mst_i2c_spi.c: Introduce ISP enter param

This is needed to avoid attempt entering ISP mode multiple
times. The ISP mode can only exit after a reset, so once the
reset MCU parameter is set to 0, the device will not able to
exit from ISP mode and hence shouldn't enter ISP again on
the next operation.
Without exit ISP mode, the device data, like firmware version,
will not show the correct value, this param will also help
to identify this situation.

BUG=b:152558985,b:148745673
BRANCH=none
TEST=build and run:
$ flashrom -p realtek_mst_i2c_spi:bus=x,reset-mcu=0,enter-isp=1 \
    -l layout -i PARTITION1:fw -w
$ flashrom -p realtek_mst_i2c_spi:bus=x,reset-mcu=0,enter-isp=0 \
    -l layout -i FLAG1:flag -w
then either reset computer to allow update to take effect, or:
$ flashrom -p realtek_mst_i2c_spi:bus=x,reset-mcu=1,enter-isp=0 \
    --flash-size
to trigger the update.

Signed-off-by: Shiyu Sun <sshiyu@chromium.org>
Change-Id: I58931ac8b42ab55829f102d243aea6fcfd632e3e
Reviewed-on: https://review.coreboot.org/c/flashrom/+/46623
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
1 file changed