[PATCH] arm: exynos: Read default MMC device from XOM[7:5] pins

[Marek Szyprowski]

XOM pins provide information for iROM bootloader about the boot device.
Those pins are mapped to lower bits of OP_MODE register (0x10000008),
which is common for all Exynos SoC variants. Set the default MMC device id
to reflect the boot device selected by XOM[7:5] pins (2 for the SD or 0 for
the eMMC).

Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
 arch/arm/mach-exynos/include/mach/cpu.h |  1 +
 board/samsung/common/board.c            | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/arch/arm/mach-exynos/include/mach/cpu.h b/arch/arm/mach-exynos/include/mach/cpu.h
index 766edeeb29..fb5fdaf3ba 100644
--- a/arch/arm/mach-exynos/include/mach/cpu.h
+++ b/arch/arm/mach-exynos/include/mach/cpu.h
@@ -17,6 +17,7 @@
 
 #define EXYNOS4_GPIO_PART3_BASE		0x03860000
 #define EXYNOS4_PRO_ID			0x10000000
+#define EXYNOS4_OP_MODE			0x10000008
 #define EXYNOS4_SYSREG_BASE		0x10010000
 #define EXYNOS4_POWER_BASE		0x10020000
 #define EXYNOS4_SWRESET			0x10020400
diff --git a/board/samsung/common/board.c b/board/samsung/common/board.c
index ee2fc7971e..ac91c0a6fb 100644
--- a/board/samsung/common/board.c
+++ b/board/samsung/common/board.c
@@ -359,3 +359,17 @@ int board_usb_cleanup(int index, enum usb_init_type init)
 #endif
 	return 0;
 }
+
+/**
+ * mmc_get_env_dev() - read boot MMC device id from XOM[7:5] pins.
+ */
+int mmc_get_env_dev(void)
+{
+	u32 mode = readl(EXYNOS4_OP_MODE) & 0x1C;
+
+	if (mode == 0x04)
+		return 2; /* MMC2: SD */
+
+	/* MMC0: eMMC or unknown */
+	return 0;
+}
-- 
2.17.1