sdhci: Add support for hosts reporting inverted write-protect state

This patch adds SDHCI_QUIRK_INVERTED_WRITE_PROTECT quirk. When
specified, the sdhci driver will invert WP state.

p.s. Actually, the quirk is more board-specific than
     controller-specific.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/host/sdhci.c

@@ -1149,6 +1149,8 @@ static int sdhci_get_ro(struct mmc_host *mmc)
 
 	spin_unlock_irqrestore(&host->lock, flags);
 
+	if (host->quirks & SDHCI_QUIRK_INVERTED_WRITE_PROTECT)
+		return !!(present & SDHCI_WRITE_PROTECT);
 	return !(present & SDHCI_WRITE_PROTECT);
 }
 

drivers/mmc/host/sdhci.h

@@ -216,6 +216,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK_NO_BUSY_IRQ				(1<<14)
 /* Controller has unreliable card detection */
 #define SDHCI_QUIRK_BROKEN_CARD_DETECTION		(1<<15)
+/* Controller reports inverted write-protect state */
+#define SDHCI_QUIRK_INVERTED_WRITE_PROTECT		(1<<16)
 
 	int			irq;		/* Device IRQ */
 	void __iomem *		ioaddr;		/* Mapped address */