[PATCH 4.4 15/28] mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

Greg Kroah-Hartman
2017-04-25T15:35:05Z

From: Haibo Chen <haibo.chen@nxp.com>

commit 9f327845358d3dd0d8a5a7a5436b0aa5c432e757 upstream.

Currently for DDR50 card, it need tuning in default. We meet tuning fail
issue for DDR50 card and some data CRC error when DDR50 sd card works.

This is because the default pad I/O drive strength can't make sure DDR50
card work stable. So increase the pad I/O drive strength for DDR50 card,
and use pins_100mhz.

This fixes DDR50 card support for IMX since DDR50 tuning was enabled from
commit 9faac7b95ea4 ("mmc: sdhci: enable tuning for DDR50")

Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mmc/host/sdhci-esdhc-imx.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -804,6 +804,7 @@ static int esdhc_change_pinstate(struct

switch (uhs) {
case MMC_TIMING_UHS_SDR50:
+ case MMC_TIMING_UHS_DDR50:
pinctrl = imx_data->pins_100mhz;
break;
case MMC_TIMING_UHS_SDR104: