mmc: sdhci-of-arasan: Use Mask writes for Tap delays

Mask the ITAP and OTAP delay bits before updating with the new
tap value for Versal platform.

Fixes: 1a47072 ("sdhci: arasan: Add support for Versal Tap Delays")
Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1605515565-117562-3-git-send-email-manish.narani@xilinx.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-of-arasan.c

@@ -30,7 +30,10 @@
 #define SDHCI_ARASAN_VENDOR_REGISTER	0x78
 
 #define SDHCI_ARASAN_ITAPDLY_REGISTER	0xF0F8
+#define SDHCI_ARASAN_ITAPDLY_SEL_MASK	0xFF
+
 #define SDHCI_ARASAN_OTAPDLY_REGISTER	0xF0FC
+#define SDHCI_ARASAN_OTAPDLY_SEL_MASK	0x3F
 
 #define SDHCI_ARASAN_CQE_BASE_ADDR	0x200
 #define VENDOR_ENHANCED_STROBE		BIT(0)
@@ -755,6 +758,7 @@ static int sdhci_versal_sdcardclk_set_phase(struct clk_hw *hw, int degrees)
 		regval = sdhci_readl(host, SDHCI_ARASAN_OTAPDLY_REGISTER);
 		regval |= SDHCI_OTAPDLY_ENABLE;
 		sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
+		regval &= ~SDHCI_ARASAN_OTAPDLY_SEL_MASK;
 		regval |= tap_delay;
 		sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
 	}
@@ -822,6 +826,7 @@ static int sdhci_versal_sampleclk_set_phase(struct clk_hw *hw, int degrees)
 		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
 		regval |= SDHCI_ITAPDLY_ENABLE;
 		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
+		regval &= ~SDHCI_ARASAN_ITAPDLY_SEL_MASK;
 		regval |= tap_delay;
 		sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
 		regval &= ~SDHCI_ITAPDLY_CHGWIN;