am33xx: Add SPI SPL as an option

Add the required config.mk logic for this SoC as well as the BOOT_DEVICE
define.  Finally, enable the options on the am335x_evm.

Signed-off-by: Tom Rini <trini@ti.com>

arch/arm/cpu/armv7/am33xx/config.mk

@@ -13,6 +13,7 @@
 #
 ifdef CONFIG_SPL_BUILD
 ALL-y	+= $(OBJTREE)/MLO
+ALL-$(CONFIG_SPL_SPI_SUPPORT) += $(OBJTREE)/MLO.byteswap
 else
 ALL-y	+= $(obj)u-boot.img
 endif

arch/arm/include/asm/arch-am33xx/spl.h

@@ -27,6 +27,7 @@
 #define BOOT_DEVICE_NAND	5
 #define BOOT_DEVICE_MMC1	8
 #define BOOT_DEVICE_MMC2	9	/* eMMC or daughter card */
+#define BOOT_DEVICE_SPI		11
 #define BOOT_DEVICE_UART	65
 #define BOOT_DEVICE_CPGMAC	70
 #define BOOT_DEVICE_MMC2_2      0xFF

include/configs/am335x_evm.h

@@ -218,6 +218,13 @@
 #define CONFIG_SPL_NET_SUPPORT
 #define CONFIG_SPL_NET_VCI_STRING	"AM335x U-Boot SPL"
 #define CONFIG_SPL_ETH_SUPPORT
+#define CONFIG_SPL_SPI_SUPPORT
+#define CONFIG_SPL_SPI_FLASH_SUPPORT
+#define CONFIG_SPL_SPI_LOAD
+#define CONFIG_SPL_SPI_BUS		0
+#define CONFIG_SPL_SPI_CS		0
+#define CONFIG_SYS_SPI_U_BOOT_OFFS	0x20000
+#define CONFIG_SYS_SPI_U_BOOT_SIZE	0x40000
 #define CONFIG_SPL_LDSCRIPT		"$(CPUDIR)/omap-common/u-boot-spl.lds"
 
 /*