[U-Boot] [PATCH] arm: imx: make bmode command work with SPL/U-Boot combo

[Nikita Kiryanov]

The bmode command forces the SoC to use a specific boot device
by writing its boot mode into SRC_GPR9, and notifying the SoC of
the change using SRC_GPR10[28] bit: if the bit is on, bootROM
uses the value in SRC_GPR9 instead of SRC_SMBR1 to determine
the boot device.

SPL on the other hand is oblivious to this distinction, so once
the bootROM loads SPL from the device configured in SRC_GPR10,
SPL will attempt to load U-Boot from the device configured in
SRC_SMBR1, which is not updated by the bootROM to the value in
SRC_GPR9.

The result is that the selected boot device is not used across all
the boot stages.

Update spl_boot_device() to look at gpr9 when necessary.

Signed-off-by: Nikita Kiryanov <nikita at compulab.co.il>
Cc: Stefano Babic <sbabic at denx.de>
Cc: Troy Kisky <troy.kisky at boundarydevices.com>
Cc: Tim Harvey <tharvey at gateworks.com>
Cc: Eric Nelson <eric.nelson at boundarydevices.com>
Cc: Fabio Estevam <fabio.estevam at freescale.com>
Cc: Heiko Schocher <hs at denx.de>
---
 arch/arm/cpu/armv7/mx6/soc.c | 4 ++--
 arch/arm/imx-common/spl.c    | 5 +++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index dd5aaa2..07ae79e 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -333,8 +333,8 @@ void boot_mode_apply(unsigned cfg_val)
 /*
  * cfg_val will be used for
  * Boot_cfg4[7:0]:Boot_cfg3[7:0]:Boot_cfg2[7:0]:Boot_cfg1[7:0]
- * After reset, if GPR10[28] is 1, ROM will copy GPR9[25:0]
- * to SBMR1, which will determine the boot device.
+ * After reset, if GPR10[28] is 1, ROM will use GPR9[25:0]
+ * instead of SBMR1 to determine the boot device.
  */
 const struct boot_mode soc_boot_modes[] = {
 	{"normal",	MAKE_CFGVAL(0x00, 0x00, 0x00, 0x00)},
diff --git a/arch/arm/imx-common/spl.c b/arch/arm/imx-common/spl.c
index 9d3c31a..477c38c 100644
--- a/arch/arm/imx-common/spl.c
+++ b/arch/arm/imx-common/spl.c
@@ -14,11 +14,12 @@
 #include <spl.h>
 
 #if defined(CONFIG_MX6)
-/* determine boot device from SRC_SBMR1 register (BOOT_CFG[4:1]) */
+/* determine boot device from SRC_SBMR1 (BOOT_CFG[4:1]) or SRC_GPR9 register */
 u32 spl_boot_device(void)
 {
 	struct src *psrc = (struct src *)SRC_BASE_ADDR;
-	unsigned reg = readl(&psrc->sbmr1);
+	unsigned int gpr10_boot = readl(&psrc->gpr10) & (1 << 28);
+	unsigned reg = gpr10_boot ? readl(&psrc->gpr9) : readl(&psrc->sbmr1);
 
 	/* BOOT_CFG1[7:4] - see IMX6DQRM Table 8-8 */
 	switch ((reg & 0x000000FF) >> 4) {
-- 
1.9.1