[MMC] sdhci: check controller version

Check the interface version of the controller and bail out if it's an unknown
version.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/mmc/sdhci.c

@@ -1073,6 +1073,7 @@ static int sdhci_resume (struct pci_dev *pdev)
 static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
 {
 	int ret;
+	unsigned int version;
 	struct sdhci_chip *chip;
 	struct mmc_host *mmc;
 	struct sdhci_host *host;
@@ -1131,6 +1132,16 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
 		goto release;
 	}
 
+	version = readw(host->ioaddr + SDHCI_HOST_VERSION);
+	version = (version & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT;
+	if (version != 0) {
+		printk(KERN_ERR "%s: Unknown controller version (%d). "
+			"Cowardly refusing to continue.\n", host->slot_descr,
+			version);
+		ret = -ENODEV;
+		goto unmap;
+	}
+
 	caps = readl(host->ioaddr + SDHCI_CAPABILITIES);
 
 	if ((caps & SDHCI_CAN_DO_DMA) && ((pdev->class & 0x0000FF) == 0x01))

drivers/mmc/sdhci.h

@@ -149,6 +149,10 @@
 #define SDHCI_SLOT_INT_STATUS	0xFC
 
 #define SDHCI_HOST_VERSION	0xFE
+#define  SDHCI_VENDOR_VER_MASK	0xFF00
+#define  SDHCI_VENDOR_VER_SHIFT	8
+#define  SDHCI_SPEC_VER_MASK	0x00FF
+#define  SDHCI_SPEC_VER_SHIFT	0
 
 struct sdhci_chip;