davinci: MMC: add support for 8bit MMC cards

Add support for 8bit MMC cards.  The controller data width is configurable
depending on the wires setting in the platform data structure.

MMC 8bit is tested on OMAPL137 and MMC 4bit is tested on OMAPL138 EVM.
Signed-off-by: Vipin Bhandari <vipin.bhandari@ti.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Chaithrika U S <chaithrika@ti.com>
Cc: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/davinci_mmc.c

@@ -73,6 +73,7 @@
 /* DAVINCI_MMCCTL definitions */
 #define MMCCTL_DATRST         (1 << 0)
 #define MMCCTL_CMDRST         (1 << 1)
+#define MMCCTL_WIDTH_8_BIT    (1 << 8)
 #define MMCCTL_WIDTH_4_BIT    (1 << 2)
 #define MMCCTL_DATEG_DISABLED (0 << 6)
 #define MMCCTL_DATEG_RISING   (1 << 6)
@@ -791,22 +792,42 @@ static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
 
 static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
-	unsigned int mmc_pclk = 0;
 	struct mmc_davinci_host *host = mmc_priv(mmc);
 
-	mmc_pclk = host->mmc_input_clk;
 	dev_dbg(mmc_dev(host->mmc),
 		"clock %dHz busmode %d powermode %d Vdd %04x\n",
 		ios->clock, ios->bus_mode, ios->power_mode,
 		ios->vdd);
-	if (ios->bus_width == MMC_BUS_WIDTH_4) {
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_8:
+		dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
+		writel((readl(host->base + DAVINCI_MMCCTL) &
+			~MMCCTL_WIDTH_4_BIT) | MMCCTL_WIDTH_8_BIT,
+			host->base + DAVINCI_MMCCTL);
+		break;
+	case MMC_BUS_WIDTH_4:
 		dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
-		writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
+		if (host->version == MMC_CTLR_VERSION_2)
+			writel((readl(host->base + DAVINCI_MMCCTL) &
+				~MMCCTL_WIDTH_8_BIT) | MMCCTL_WIDTH_4_BIT,
 				host->base + DAVINCI_MMCCTL);
-	} else {
-		dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
-		writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
+		else
+			writel(readl(host->base + DAVINCI_MMCCTL) |
+				MMCCTL_WIDTH_4_BIT,
 				host->base + DAVINCI_MMCCTL);
+		break;
+	case MMC_BUS_WIDTH_1:
+		dev_dbg(mmc_dev(host->mmc), "Enabling 1 bit mode\n");
+		if (host->version == MMC_CTLR_VERSION_2)
+			writel(readl(host->base + DAVINCI_MMCCTL) &
+				~(MMCCTL_WIDTH_8_BIT | MMCCTL_WIDTH_4_BIT),
+				host->base + DAVINCI_MMCCTL);
+		else
+			writel(readl(host->base + DAVINCI_MMCCTL) &
+				~MMCCTL_WIDTH_4_BIT,
+				host->base + DAVINCI_MMCCTL);
+		break;
 	}
 
 	calculate_clk_divider(mmc, ios);
@@ -1189,10 +1210,14 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
 
 	/* REVISIT:  someday, support IRQ-driven card detection.  */
 	mmc->caps |= MMC_CAP_NEEDS_POLL;
+	mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
 
-	if (!pdata || pdata->wires == 4 || pdata->wires == 0)
+	if (pdata && (pdata->wires == 4 || pdata->wires == 0))
 		mmc->caps |= MMC_CAP_4_BIT_DATA;
 
+	if (pdata && (pdata->wires == 8))
+		mmc->caps |= (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA);
+
 	host->version = pdata->version;
 
 	mmc->ops = &mmc_davinci_ops;