mmc: sdhci: Read capabilities register1 and update host caps

This patch reads the capabilities register1 and update the host
caps accordingly for mmc layer usage. This patch mainly reads
for UHS capabilities inorder to support SD3.0.

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

drivers/mmc/sdhci.c

@@ -557,7 +557,7 @@ static const struct mmc_ops sdhci_ops = {
 int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
 		u32 f_max, u32 f_min)
 {
-	u32 caps, caps_1;
+	u32 caps, caps_1 = 0;
 
 	caps = sdhci_readl(host, SDHCI_CAPABILITIES);
 
@@ -638,6 +638,32 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
 		cfg->host_caps &= ~MMC_MODE_HS_52MHz;
 	}
 
+	if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300)
+		caps_1 = sdhci_readl(host, SDHCI_CAPABILITIES_1);
+
+	if (!(cfg->voltages & MMC_VDD_165_195) ||
+	    (host->quirks & SDHCI_QUIRK_NO_1_8_V))
+		caps_1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
+			    SDHCI_SUPPORT_DDR50);
+
+	if (caps_1 & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
+		      SDHCI_SUPPORT_DDR50))
+		cfg->host_caps |= MMC_CAP(UHS_SDR12) | MMC_CAP(UHS_SDR25);
+
+	if (caps_1 & SDHCI_SUPPORT_SDR104) {
+		cfg->host_caps |= MMC_CAP(UHS_SDR104) | MMC_CAP(UHS_SDR50);
+		/*
+		 * SD3.0: SDR104 is supported so (for eMMC) the caps2
+		 * field can be promoted to support HS200.
+		 */
+		cfg->host_caps |= MMC_CAP(MMC_HS_200);
+	} else if (caps_1 & SDHCI_SUPPORT_SDR50) {
+		cfg->host_caps |= MMC_CAP(UHS_SDR50);
+	}
+
+	if (caps_1 & SDHCI_SUPPORT_DDR50)
+		cfg->host_caps |= MMC_CAP(UHS_DDR50);
+
 	if (host->host_caps)
 		cfg->host_caps |= host->host_caps;
 

include/sdhci.h

@@ -166,6 +166,11 @@
 #define  SDHCI_CAN_64BIT	BIT(28)
 
 #define SDHCI_CAPABILITIES_1	0x44
+#define  SDHCI_SUPPORT_SDR50	0x00000001
+#define  SDHCI_SUPPORT_SDR104	0x00000002
+#define  SDHCI_SUPPORT_DDR50	0x00000004
+#define  SDHCI_USE_SDR50_TUNING	0x00002000
+
 #define  SDHCI_CLOCK_MUL_MASK	0x00FF0000
 #define  SDHCI_CLOCK_MUL_SHIFT	16
 
@@ -220,6 +225,7 @@
 #define SDHCI_QUIRK_BROKEN_HISPD_MODE	BIT(5)
 #define SDHCI_QUIRK_WAIT_SEND_CMD	(1 << 6)
 #define SDHCI_QUIRK_USE_WIDE8		(1 << 8)
+#define SDHCI_QUIRK_NO_1_8_V		(1 << 9)
 
 /* to make gcc happy */
 struct sdhci_host;