[PATCH] board: stm32mp1: use CONFIG_SYS_MMC_ENV_DEV when available

[Patrick Delaunay]

Check whether user has explicitly defined the mmc device to use
in mmc_get_env_dev() with CONFIG_SYS_MMC_ENV_DEV.

On STMicroelectronics boards the used mmc device for environment is
the instance of boot device provided by the ROM code; the mmc instance
is configured by alias in device tree. The used partition is defined in
device tree with u-boot,mmc-env-partition = "ssbl".

This patch allows to override this selection for the support of customer
boards without alias; for example when SDMMC1 is not used and ENV in
mmc0=SDMMC2, user can force the value: CONFIG_SYS_MMC_ENV_DEV = 0.

On STMicroelectronics boards, the current behavior is kept with
CONFIG_SYS_MMC_ENV_DEV = -1.

Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---

 board/st/stm32mp1/stm32mp1.c        | 8 +++++++-
 configs/stm32mp15_basic_defconfig   | 1 +
 configs/stm32mp15_trusted_defconfig | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index ab85d8ba68..759181fb5d 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -862,8 +862,14 @@ const char *env_ext4_get_dev_part(void)
 
 int mmc_get_env_dev(void)
 {
-	u32 bootmode = get_bootmode();
+	u32 bootmode;
+
+	if (CONFIG_SYS_MMC_ENV_DEV >= 0)
+		return CONFIG_SYS_MMC_ENV_DEV;
+
+	bootmode = get_bootmode();
 
+	/* use boot instance to select the correct mmc device identifier */
 	return (bootmode & TAMP_BOOT_INSTANCE_MASK) - 1;
 }
 
diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index 1c680984b8..a2f745099e 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -71,6 +71,7 @@ CONFIG_ENV_UBI_PART="UBI"
 CONFIG_ENV_UBI_VOLUME="uboot_config"
 CONFIG_ENV_UBI_VOLUME_REDUND="uboot_config_r"
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_SYS_MMC_ENV_DEV=-1
 # CONFIG_SPL_ENV_IS_NOWHERE is not set
 # CONFIG_SPL_ENV_IS_IN_SPI_FLASH is not set
 CONFIG_STM32_ADC=y
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index 107041119f..f41aaa750f 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -52,6 +52,7 @@ CONFIG_ENV_UBI_PART="UBI"
 CONFIG_ENV_UBI_VOLUME="uboot_config"
 CONFIG_ENV_UBI_VOLUME_REDUND="uboot_config_r"
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_SYS_MMC_ENV_DEV=-1
 CONFIG_STM32_ADC=y
 CONFIG_SET_DFU_ALT_INFO=y
 CONFIG_USB_FUNCTION_FASTBOOT=y
-- 
2.17.1