When CMD13 is sent after switching to HS400ES mode, the bus
is operating at either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR.
To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI
interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host
controller CAR clock and the interface clock are rate matched.
Signed-off-by: Prathamesh Shete <pshete@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 43 ++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 17 deletions(-)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 387ce9cdbd7c..ddaa3d9000f6 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -354,23 +354,6 @@ static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
}
}
-static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc,
- struct mmc_ios *ios)
-{
- struct sdhci_host *host = mmc_priv(mmc);
- u32 val;
-
- val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
-
- if (ios->enhanced_strobe)
- val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
- else
- val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
-
- sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
-
-}
-
static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -791,6 +774,32 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
}
}
+static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc,
+ struct mmc_ios *ios)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ u32 val;
+
+ val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
+
+ if (ios->enhanced_strobe) {
+ val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
+ /*
+ * When CMD13 is sent from mmc_select_hs400es() after
+ * switching to HS400ES mode, the bus is operating at
+ * either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR.
+ * To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI
+ * interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host
+ * controller CAR clock and the interface clock are rate matched.
+ */
+ tegra_sdhci_set_clock(host, MMC_HS200_MAX_DTR);
+ } else {
+ val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
+ }
+
+ sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
+}
+
static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
--
2.17.1
