mmc: sdhci: add support for realtek rts5250

Add support for realtek rts5250 pci card reader. The card reader has
some problems with DDR50 mode, so add a new quirks2 for broken ddr50.
Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
Signed-off-by: Chris Ball <chris@printf.net>

drivers/mmc/host/sdhci-pci.c

@@ -610,6 +610,18 @@ static const struct sdhci_pci_fixes sdhci_via = {
 	.probe		= via_probe,
 };
 
+static int rtsx_probe_slot(struct sdhci_pci_slot *slot)
+{
+	slot->host->mmc->caps2 |= MMC_CAP2_HS200;
+	return 0;
+}
+
+static const struct sdhci_pci_fixes sdhci_rtsx = {
+	.quirks2	= SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
+			SDHCI_QUIRK2_BROKEN_DDR50,
+	.probe_slot	= rtsx_probe_slot,
+};
+
 static const struct pci_device_id pci_ids[] = {
 	{
 		.vendor		= PCI_VENDOR_ID_RICOH,
@@ -731,6 +743,14 @@ static const struct pci_device_id pci_ids[] = {
 		.driver_data	= (kernel_ulong_t)&sdhci_via,
 	},
 
+	{
+		.vendor		= PCI_VENDOR_ID_REALTEK,
+		.device		= 0x5250,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.driver_data	= (kernel_ulong_t)&sdhci_rtsx,
+	},
+
 	{
 		.vendor		= PCI_VENDOR_ID_INTEL,
 		.device		= PCI_DEVICE_ID_INTEL_MRST_SD0,

drivers/mmc/host/sdhci.c

@@ -3020,7 +3020,8 @@ int sdhci_add_host(struct sdhci_host *host)
 	} else if (caps[1] & SDHCI_SUPPORT_SDR50)
 		mmc->caps |= MMC_CAP_UHS_SDR50;
 
-	if (caps[1] & SDHCI_SUPPORT_DDR50)
+	if ((caps[1] & SDHCI_SUPPORT_DDR50) &&
+		!(host->quirks2 & SDHCI_QUIRK2_BROKEN_DDR50))
 		mmc->caps |= MMC_CAP_UHS_DDR50;
 
 	/* Does the host need tuning for SDR50? */

include/linux/mmc/sdhci.h

@@ -100,6 +100,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK2_BROKEN_HOST_CONTROL		(1<<5)
 /* Controller does not support HS200 */
 #define SDHCI_QUIRK2_BROKEN_HS200			(1<<6)
+/* Controller does not support DDR50 */
+#define SDHCI_QUIRK2_BROKEN_DDR50			(1<<7)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */