mmc: sdhci-of-esdhc: temporary fixup for eMMC HS400 issue

Currently only LX2160A eSDHC supports eMMC HS400. According to
a large number of tests, eMMC HS400 failed to work at 150MHz,
and for a few boards failed to work at 175MHz. But eMMC HS400
worked fine on 200MHz. We hadn't found the root cause but
setting eSDHC_DLLCFG0[DLL_FREQ_SEL] = 0 using slow delay chain
seemed to resovle this issue. Let's use this as fixup for now.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index b73d75251f8a965faee4030eb480db60e9addca9..b93a4556ac8cada45144a148d88f5f4b74b2bd9f 100644 (file)
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -623,7 +623,9 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
                esdhc_clock_enable(host, true);
 
                temp = sdhci_readl(host, ESDHC_DLLCFG0);
-               temp |= ESDHC_DLL_ENABLE | ESDHC_DLL_FREQ_SEL;
+               temp |= ESDHC_DLL_ENABLE;
+               if (host->mmc->actual_clock == MMC_HS200_MAX_DTR)
+                       temp |= ESDHC_DLL_FREQ_SEL;
                sdhci_writel(host, temp, ESDHC_DLLCFG0);
                temp = sdhci_readl(host, ESDHC_TBCTL);
                sdhci_writel(host, temp | ESDHC_HS400_WNDW_ADJUST, ESDHC_TBCTL);