mmc: sdhci: add hooks for setting UHS in platform specific code

Allow platform specific code to set UHS registers if
implementation requires speciial platform specific handling
Signed-off-by: Philip Rakity <prakity@marvell.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci.c

@@ -1346,8 +1346,16 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 			sdhci_set_clock(host, clock);
 		}
 
-		ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 
+		/* Reset SD Clock Enable */
+		clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+		clk &= ~SDHCI_CLOCK_CARD_EN;
+		sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+		if (host->ops->set_uhs_signaling)
+			host->ops->set_uhs_signaling(host, ios->timing);
+		else {
+			ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 			/* Select Bus Speed Mode for host */
 			ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
 			if (ios->timing == MMC_TIMING_UHS_SDR12)
@@ -1360,13 +1368,8 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
 			else if (ios->timing == MMC_TIMING_UHS_DDR50)
 				ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
-
-		/* Reset SD Clock Enable */
-		clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
-		clk &= ~SDHCI_CLOCK_CARD_EN;
-		sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
-
 			sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+		}
 
 		/* Re-enable SD Clock */
 		clock = host->clock;

drivers/mmc/host/sdhci.h

@@ -270,6 +270,8 @@ struct sdhci_ops {
 	unsigned int    (*get_ro)(struct sdhci_host *host);
 	void	(*platform_reset_enter)(struct sdhci_host *host, u8 mask);
 	void	(*platform_reset_exit)(struct sdhci_host *host, u8 mask);
+	int	(*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs);
+
 };
 
 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS