mmc: add hs400 enhanced strobe support for mmc subsystem

[firefly-linux-kernel-4.4.55.git] / drivers / mmc / host / sdhci-of-arasan.c

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 4cdb97c300ff6e578fb3f182ee8127e0f7e66a65..426750bed6fa3b321d1aa2c166b662ee40f7839e 100644 (file)
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -25,7 +25,9 @@
 #include "sdhci-pltfm.h"
 
 #define SDHCI_ARASAN_CLK_CTRL_OFFSET   0x2c
+#define SDHCI_ARASAN_VENDOR_REGISTER   0x78
 
+#define VENDOR_ENHANCED_STROBE         BIT(0)
 #define CLK_CTRL_TIMEOUT_SHIFT         16
 #define CLK_CTRL_TIMEOUT_MASK          (0xf << CLK_CTRL_TIMEOUT_SHIFT)
 #define CLK_CTRL_TIMEOUT_MIN_EXP       13
@@ -55,6 +57,23 @@ static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
        return freq;
 }
 
+static int sdhci_arasan_enhanced_strobe(struct mmc_host *mmc,
+                                       bool enable)
+{
+       u32 vendor;
+       struct sdhci_host *host = mmc_priv(mmc);
+
+       vendor = readl(host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+       if (enable)
+               vendor |= VENDOR_ENHANCED_STROBE;
+       else
+               vendor &= (~VENDOR_ENHANCED_STROBE);
+
+       writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+
+       return 0;
+}
+
 static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
 {
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -249,6 +268,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
                        dev_err(&pdev->dev, "phy_power_on err.\n");
                        goto err_phy_power;
                }
+
+               host->mmc_host_ops.prepare_enhanced_strobe =
+                                       sdhci_arasan_enhanced_strobe;
        }
 
        ret = sdhci_add_host(host);