imx: imx6ul: kontron-sl-mx6ul: Select correct boot and env device

Instead of checking both, SPI NOR and MMC for loading U-Boot proper
and the environment, implement a way to detect the actual boot
device even if the BootROM doesn't report it and we can't rely
solely on the fuse settings, as by default we use MMC as primary
boot device and boot from SPI NOR via the secondary fallback device
(EEPROM Recovery Mode).

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>

1 files changed, 14 insertions, 9 deletions

diff --git a/board/kontron/sl-mx6ul/spl.c b/board/kontron/sl-mx6ul/spl.c
index 12b0352146..ba6915c898 100644
--- a/board/kontron/sl-mx6ul/spl.c
+++ b/board/kontron/sl-mx6ul/spl.c
@@ -17,6 +17,7 @@
 #include <linux/sizes.h>
 #include <linux/errno.h>
 #include <mmc.h>
+#include <sl-mx6ul-common.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -339,26 +340,30 @@ void board_boot_order(u32 *spl_boot_list)
 
 	/*
 	 * The default boot fuse settings use the SD card (MMC1) as primary
-	 * boot device, but allow SPI NOR as a fallback boot device.
-	 * We can't detect the fallback case and spl_boot_device() will return
-	 * BOOT_DEVICE_MMC1 despite the actual boot device being SPI NOR.
-	 * Therefore we try to load U-Boot proper vom SPI NOR after loading
-	 * from MMC has failed.
+	 * boot device, but allow SPI NOR as a fallback boot device. There
+	 * is no proper way to detect if the fallback was used. Therefore
+	 * we read the ECSPI2_CONREG register and see if it differs from the
+	 * reset value 0x0. If that's the case we can assume that the BootROM
+	 * has successfully probed the SPI NOR.
 	 */
-	spl_boot_list[0] = bootdev;
-
 	switch (bootdev) {
 	case BOOT_DEVICE_MMC1:
 	case BOOT_DEVICE_MMC2:
-		spl_boot_list[1] = BOOT_DEVICE_SPI;
+		if (sl_mx6ul_is_spi_nor_boot()) {
+			spl_boot_list[0] = BOOT_DEVICE_SPI;
+			return;
+		}
 		break;
 	}
+
+	spl_boot_list[0] = bootdev;
 }
 
 int board_early_init_f(void)
 {
 	setup_iomux_uart();
-	setup_spi();
+	if (sl_mx6ul_is_spi_nor_boot())
+		setup_spi();
 
 	return 0;
 }