mmc: mv_sdhci: fix 8bus width access for 88SV331xV5

Marvell 88SV331xV5 platform's sdhci host control is not very standard
with the spec in the 8bit handling. It need to set its private register
to switch to the 8bit mode which is not included in the standard sdhci
registers.

This patch mainly hacks the writeb method, and set its private register
if it find the driver is going to switch to the 8bit mode.

Signed-off-by: Lei Wen <leiwen@marvell.com>
diff --git a/drivers/mmc/mv_sdhci.c b/drivers/mmc/mv_sdhci.c
index 9e59951..f92caeb 100644
--- a/drivers/mmc/mv_sdhci.c
+++ b/drivers/mmc/mv_sdhci.c
@@ -2,6 +2,33 @@
 #include <malloc.h>
 #include <sdhci.h>
 
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
+static struct sdhci_ops mv_ops;
+
+#if defined(CONFIG_SHEEVA_88SV331xV5)
+#define SD_CE_ATA_2	0xEA
+#define  MMC_CARD	0x1000
+#define  MMC_WIDTH	0x0100
+static inline void mv_sdhci_writeb(struct sdhci_host *host, u8 val, int reg)
+{
+	struct mmc *mmc = host->mmc;
+	u32 ata = (u32)host->ioaddr + SD_CE_ATA_2;
+
+	if (!IS_SD(mmc) && reg == SDHCI_HOST_CONTROL) {
+		if (mmc->bus_width == 8)
+			writew(readw(ata) | (MMC_CARD | MMC_WIDTH), ata);
+		else
+			writew(readw(ata) & ~(MMC_CARD | MMC_WIDTH), ata);
+	}
+
+	writeb(val, host->ioaddr + reg);
+}
+
+#else
+#define mv_sdhci_writeb	NULL
+#endif /* CONFIG_SHEEVA_88SV331xV5 */
+#endif /* CONFIG_MMC_SDHCI_IO_ACCESSORS */
+
 static char *MVSDH_NAME = "mv_sdh";
 int mv_sdh_init(u32 regbase, u32 max_clk, u32 min_clk, u32 quirks)
 {
@@ -15,6 +42,12 @@
 	host->name = MVSDH_NAME;
 	host->ioaddr = (void *)regbase;
 	host->quirks = quirks;
+#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
+	memset(&mv_ops, 0, sizeof(struct sdhci_ops));
+	if (mv_sdhci_writeb != NULL)
+		mv_ops.write_b = mv_sdhci_writeb;
+	host->ops = &mv_ops;
+#endif
 	host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
 	add_sdhci(host, max_clk, min_clk);
 	return 0;