mmc: renesas_sdhi: only check CMD status for HS400 manual correction
R-Car Gen3 cannot use correction error status with HS400.
HS200: CMD and DAT signal timing are based on CLK signal.
HS400: CMD signal is based on CLK. DAT signal is based on DS signal.
In HS400, CMD signal is 200MHz(SDR). DAT signal is 200MHz(DDR).
Center position of signal is different between CMD and DAT.
TAP position should be adjusted to the center position of CMD signal.
DAT sampling timing is adjusted by HS400 calibration circuit regardless
of TAP position. Refer to renesas_sdhi_adjust_hs400mode_enable().
However, correction error status contains CMD and DAT status in HS400
(DAT signal is not masked in HS400). Therefore, correction error status
cannot use in HS400. It means that auto correction cannot be uses in
HS400. Manual correction can change to the correct TAP position by
ignoring DAT correction error status and using only CMD correction
status.
Signed-off-by: Takeshi Saito <takeshi.saito.xv@renesas.com>
[wsa: refactored patch from BSP]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20191217114034.13290-4-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
1 file changed