[U-Boot] [RFC] spl: imx6: Let spl_boot_device return USDHC1 or USDHC2

[Adam Ford]

Currently, when the spl_boot_device checks the boot device, it
will only return MMC1 when it's either sd or eMMC regardless
of whether or not it's MMC1 or MMC2.  This is a problem when
booting from MMC2 if MMC isn't being manually configured like in
the DM_SPL case with SPL_OF_CONTROL.

This patch will check the register and return either MMC1 or MMC2.

Signed-off-by: Adam Ford <aford173 at gmail.com>

diff --git a/arch/arm/mach-imx/spl.c b/arch/arm/mach-imx/spl.c
index 9f1e0f6a72..1f230aca33 100644
--- a/arch/arm/mach-imx/spl.c
+++ b/arch/arm/mach-imx/spl.c
@@ -24,6 +24,7 @@ u32 spl_boot_device(void)
 {
 	unsigned int bmode = readl(&src_base->sbmr2);
 	u32 reg = imx6_src_get_boot_mode();
+	u32 mmc_index = ((reg >> 11) & 0x03);
 
 	/*
 	 * Check for BMODE if serial downloader is enabled
@@ -84,11 +85,12 @@ u32 spl_boot_device(void)
 	/* SD/eSD: 8.5.3, Table 8-15  */
 	case IMX6_BMODE_SD:
 	case IMX6_BMODE_ESD:
-		return BOOT_DEVICE_MMC1;
-	/* MMC/eMMC: 8.5.3 */
 	case IMX6_BMODE_MMC:
 	case IMX6_BMODE_EMMC:
-		return BOOT_DEVICE_MMC1;
+		if (mmc_index == 1)
+			return BOOT_DEVICE_MMC2;
+		else
+			return BOOT_DEVICE_MMC1;
 	/* NAND Flash: 8.5.2, Table 8-10 */
 	case IMX6_BMODE_NAND_MIN ... IMX6_BMODE_NAND_MAX:
 		return BOOT_DEVICE_NAND;
-- 
2.17.1