[U-Boot] [PATCH v3 1/2] env_mmc: make board configurable the partition for the environment

[Hector Palacios]

This complements commit 9404a5fc7cb58 "env_mmc: allow environment to be
in an eMMC partition" by allowing boards to accommodate the partition
to use for the environment in different scenarios (similarly to what is
done with the mmc dev number). Depending on the detected boot media,
boards may decide to store the environment in a different partition.

The __weak function also allows to remove some ifdefs from the code.
If CONFIG_SYS_MMC_ENV_PART is not defined, partition 0 is assumed
(default value for U-Boot when a partition is not provided).

Signed-off-by: Hector Palacios <hector.palacios at digi.com>
Reviewed-by: Stephen Warren <swarren at nvidia.com>
---

Notes:
    Changes since v2:
    - Move CONFIG_SYS_MMC_ENV_PART to config_fallbacks
    Changes since v1:
    - Use default define if not set

 common/env_mmc.c           | 25 +++++++++++++------------
 include/config_fallbacks.h |  6 ++++++
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/common/env_mmc.c b/common/env_mmc.c
index 78c2bc7a1f08..8dbeb057a3c4 100644
--- a/common/env_mmc.c
+++ b/common/env_mmc.c
@@ -66,6 +66,11 @@ __weak int mmc_get_env_devno(void)
 	return CONFIG_SYS_MMC_ENV_DEV;
 }
 
+__weak int mmc_get_env_partno(void)
+{
+	return CONFIG_SYS_MMC_ENV_PART;
+}
+
 int env_init(void)
 {
 	/* use default */
@@ -77,6 +82,9 @@ int env_init(void)
 
 static int init_mmc_for_env(struct mmc *mmc)
 {
+	int mmc_env_devno = mmc_get_env_devno();
+	int mmc_env_partno = mmc_get_env_partno();
+
 	if (!mmc) {
 		puts("No MMC card found\n");
 		return -1;
@@ -87,30 +95,23 @@ static int init_mmc_for_env(struct mmc *mmc)
 		return -1;
 	}
 
-#ifdef CONFIG_SYS_MMC_ENV_PART
-	if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num) {
-		int mmc_env_devno = mmc_get_env_devno();
-
-		if (mmc_switch_part(mmc_env_devno,
-				    CONFIG_SYS_MMC_ENV_PART)) {
+	if (mmc_env_partno != mmc->part_num) {
+		if (mmc_switch_part(mmc_env_devno, mmc_env_partno)) {
 			puts("MMC partition switch failed\n");
 			return -1;
 		}
 	}
-#endif
 
 	return 0;
 }
 
 static void fini_mmc_for_env(struct mmc *mmc)
 {
-#ifdef CONFIG_SYS_MMC_ENV_PART
 	int mmc_env_devno = mmc_get_env_devno();
+	int mmc_env_partno = mmc_get_env_partno();
 
-	if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num)
-		mmc_switch_part(mmc_env_devno,
-				mmc->part_num);
-#endif
+	if (mmc_env_partno != mmc->part_num)
+		mmc_switch_part(mmc_env_devno, mmc->part_num);
 }
 
 #ifdef CONFIG_CMD_SAVEENV
diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h
index e59ee963f71f..7a6f55feb12e 100644
--- a/include/config_fallbacks.h
+++ b/include/config_fallbacks.h
@@ -53,4 +53,10 @@
 #define HAVE_BLOCK_DEVICE
 #endif
 
+#if defined(CONFIG_MMC)
+#if !defined(CONFIG_SYS_MMC_ENV_PART)
+#define CONFIG_SYS_MMC_ENV_PART 0
+#endif
+#endif
+
 #endif	/* __CONFIG_FALLBACKS_H */