mmc: sdhci-xenon: Support HS400 Enhanced Strobe feature

Support HS400 Enhanced Strobe feature in Xenon.

Enable Enhanced Strobe together with Data Strobe.
Disable Enhanced Strobe when eMMC is not in HS400 mode.

Signed-off-by: Hu Ziji <huziji@marvell.com>
Signed-off-by: Zhoujie Wu <zjwu@marvell.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-xenon-phy.c b/drivers/mmc/host/sdhci-xenon-phy.c
index f7e26b0..ec87943 100644 (file)
--- a/drivers/mmc/host/sdhci-xenon-phy.c
+++ b/drivers/mmc/host/sdhci-xenon-phy.c
@@ -409,17 +409,30 @@ static int xenon_emmc_phy_config_tuning(struct sdhci_host *host)
        return 0;
 }
 
-static void xenon_emmc_phy_disable_data_strobe(struct sdhci_host *host)
+static void xenon_emmc_phy_disable_strobe(struct sdhci_host *host)
 {
+       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+       struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
        u32 reg;
 
-       /* Disable SDHC Data Strobe */
+       /* Disable both SDHC Data Strobe and Enhanced Strobe */
        reg = sdhci_readl(host, XENON_SLOT_EMMC_CTRL);
-       reg &= ~XENON_ENABLE_DATA_STROBE;
+       reg &= ~(XENON_ENABLE_DATA_STROBE | XENON_ENABLE_RESP_STROBE);
        sdhci_writel(host, reg, XENON_SLOT_EMMC_CTRL);
+
+       /* Clear Strobe line Pull down or Pull up */
+       if (priv->phy_type == EMMC_5_0_PHY) {
+               reg = sdhci_readl(host, XENON_EMMC_5_0_PHY_PAD_CONTROL);
+               reg &= ~(XENON_EMMC5_FC_QSP_PD | XENON_EMMC5_FC_QSP_PU);
+               sdhci_writel(host, reg, XENON_EMMC_5_0_PHY_PAD_CONTROL);
+       } else {
+               reg = sdhci_readl(host, XENON_EMMC_PHY_PAD_CONTROL1);
+               reg &= ~(XENON_EMMC5_1_FC_QSP_PD | XENON_EMMC5_1_FC_QSP_PU);
+               sdhci_writel(host, reg, XENON_EMMC_PHY_PAD_CONTROL1);
+       }
 }
 
-/* Set HS400 Data Strobe */
+/* Set HS400 Data Strobe and Enhanced Strobe */
 static void xenon_emmc_phy_strobe_delay_adj(struct sdhci_host *host)
 {
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -439,6 +452,15 @@ static void xenon_emmc_phy_strobe_delay_adj(struct sdhci_host *host)
        /* Enable SDHC Data Strobe */
        reg = sdhci_readl(host, XENON_SLOT_EMMC_CTRL);
        reg |= XENON_ENABLE_DATA_STROBE;
+       /*
+        * Enable SDHC Enhanced Strobe if supported
+        * Xenon Enhanced Strobe should be enabled only when
+        * 1. card is in HS400 mode and
+        * 2. SDCLK is higher than 52MHz
+        * 3. DLL is enabled
+        */
+       if (host->mmc->ios.enhanced_strobe)
+               reg |= XENON_ENABLE_RESP_STROBE;
        sdhci_writel(host, reg, XENON_SLOT_EMMC_CTRL);
 
        /* Set Data Strobe Pull down */
@@ -615,7 +637,7 @@ static void xenon_emmc_phy_set(struct sdhci_host *host,
                sdhci_writel(host, phy_regs->logic_timing_val,
                             phy_regs->logic_timing_adj);
        else
-               xenon_emmc_phy_disable_data_strobe(host);
+               xenon_emmc_phy_disable_strobe(host);
 
 phy_init:
        xenon_emmc_phy_init(host);
@@ -705,7 +727,7 @@ void xenon_soc_pad_ctrl(struct sdhci_host *host,
 
 /*
  * Setting PHY when card is working in High Speed Mode.
- * HS400 set data strobe line.
+ * HS400 set Data Strobe and Enhanced Strobe if it is supported.
  * HS200/SDR104 set tuning config to prepare for tuning.
  */
 static int xenon_hs_delay_adj(struct sdhci_host *host)

diff --git a/drivers/mmc/host/sdhci-xenon.h b/drivers/mmc/host/sdhci-xenon.h
index 73debb4..01937f1 100644 (file)
--- a/drivers/mmc/host/sdhci-xenon.h
+++ b/drivers/mmc/host/sdhci-xenon.h
@@ -33,6 +33,7 @@
 #define XENON_TUNING_STEP_DIVIDER              BIT(6)
 
 #define XENON_SLOT_EMMC_CTRL                   0x0130
+#define XENON_ENABLE_RESP_STROBE               BIT(25)
 #define XENON_ENABLE_DATA_STROBE               BIT(24)
 
 #define XENON_SLOT_RETUNING_REQ_CTRL           0x0144