[PATCH v3 3/5] env: scsi: Add support for partition type GUID based environment

[Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>]

Add support for locating SCSI environment partition using GPT type
GUID instead of unique UUID. This enables the saveenv command to
work with partitions identified by their type rather than unique
identifiers, providing flexibility for systems where partition
UUIDs may vary across devices but types remain constant.

Introduce a Kconfig choice statement to select between three partition
lookup methods. The choice provides mutually exclusive options:
ENV_SCSI_PART_USE_UUID (default), ENV_SCSI_PART_USE_TYPE_GUID, and
ENV_SCSI_PART_USE_HW. The corresponding string configs depend on their
respective selection method, creating a clear configuration structure.

Introduce CONFIG_ENV_SCSI_PART_TYPE_GUID configuration option that
allows specifying a partition type GUID for environment storage.
When SCSI_ENV_PART_USE_TYPE_GUID is enabled, the environment subsystem
uses the type GUID based lookup method via
scsi_get_blk_by_type_guid() to find the first matching partition.

Refactor env/scsi.c to use compile-time preprocessor conditionals
instead of runtime string checks. Replace the previous logic that
checked if CONFIG_ENV_SCSI_PART_UUID was empty with explicit #if/#elif
branches for each method.

Elevate hardware partition selection from an implicit fallback to an
explicit choice (ENV_SCSI_PART_USE_HW), improving configuration clarity.
Move ENV_SCSI_HW_PARTITION to depend on this new option.

Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
---
Changes in v3:
- Introduce a new choice config: ENV_SCSI_PART_USE_HW for
  ENV_SCSI_HW_PARTITION
- Refactor env_scsi_get_part and env_scsi_load functions based
  on the choice configs

Changes in v2:
- Introduce a Kconfig choice config to select between UUID-based
and type GUID-based partition lookup methods.
---
 env/Kconfig | 51 +++++++++++++++++++++++++++++++++++++++++++--------
 env/scsi.c  | 45 +++++++++++++++++++++++++++------------------
 2 files changed, 70 insertions(+), 26 deletions(-)

diff --git a/env/Kconfig b/env/Kconfig
index 7abd82ab6f3..d5d956cb4ce 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -780,10 +780,51 @@ config ENV_MMC_USE_DT
 	  The 2 defines CONFIG_ENV_OFFSET, CONFIG_ENV_OFFSET_REDUND
 	  are not used as fallback.
 
+choice
+	prompt "SCSI partition selection method"
+	depends on ENV_IS_IN_SCSI
+	default ENV_SCSI_PART_USE_UUID
+	help
+	  Select the method to identify the SCSI partition for environment storage.
+
+config ENV_SCSI_PART_USE_UUID
+	bool "Use partition UUID"
+	help
+	  Use the partition's unique UUID to identify the SCSI partition
+	  for environment storage.
+
+config ENV_SCSI_PART_USE_TYPE_GUID
+	bool "Use partition type GUID"
+	help
+	  Use the partition type GUID to identify the SCSI partition
+	  for environment storage. The first partition matching the
+	  specified type GUID will be used.
+
+config ENV_SCSI_PART_USE_HW
+	bool "Use hardware partition number"
+	help
+	  Use the hardware device number to identify the SCSI device
+	  for environment storage.
+
+endchoice
+
+config ENV_SCSI_PART_UUID
+	string "SCSI partition UUID for saving environment"
+	depends on ENV_SCSI_PART_USE_UUID
+	help
+	  UUID of the SCSI partition that you want to store the environment in.
+
+config ENV_SCSI_PART_TYPE_GUID
+	string "SCSI partition type GUID for saving environment"
+	depends on ENV_SCSI_PART_USE_TYPE_GUID
+	help
+	  Type GUID of the SCSI partition to store the environment in.
+	  Uses the first partition matching this type GUID.
+
 config ENV_SCSI_HW_PARTITION
 	string "SCSI hardware partition number"
-	depends on ENV_IS_IN_SCSI
-	default 0
+	depends on ENV_SCSI_PART_USE_HW
+	default "0"
 	help
 	  SCSI hardware partition device number on the platform where the
 	  environment is stored.  Note that this is not related to any software
@@ -791,12 +832,6 @@ config ENV_SCSI_HW_PARTITION
 	  partition 0 or the first boot partition, which is 1 or some other defined
 	  partition.
 
-config ENV_SCSI_PART_UUID
-	string "SCSI partition UUID for saving environment"
-	depends on ENV_IS_IN_SCSI
-	help
-	  UUID of the SCSI partition that you want to store the environment in.
-
 config ENV_USE_DEFAULT_ENV_TEXT_FILE
 	bool "Create default environment from file"
 	depends on !COMPILE_TEST
diff --git a/env/scsi.c b/env/scsi.c
index 91a6c430302..abb8b0a1dfd 100644
--- a/env/scsi.c
+++ b/env/scsi.c
@@ -41,14 +41,19 @@ static inline struct env_scsi_info *env_scsi_get_part(void)
 		is_scsi_scanned = true;
 	}
 
-	if (CONFIG_ENV_SCSI_PART_UUID[0] == '\0') {
-		if (blk_get_device_part_str("scsi", CONFIG_ENV_SCSI_HW_PARTITION,
-					    &ep->blk, &ep->part, true))
-			return NULL;
-	} else {
-		if (scsi_get_blk_by_uuid(CONFIG_ENV_SCSI_PART_UUID, &ep->blk, &ep->part))
-			return NULL;
-	}
+#if defined(CONFIG_ENV_SCSI_PART_USE_TYPE_GUID)
+	if (scsi_get_blk_by_type_guid(CONFIG_ENV_SCSI_PART_TYPE_GUID, &ep->blk, &ep->part))
+		return NULL;
+
+#elif defined(CONFIG_ENV_SCSI_PART_USE_UUID)
+	if (scsi_get_blk_by_uuid(CONFIG_ENV_SCSI_PART_UUID, &ep->blk, &ep->part))
+		return NULL;
+
+#elif defined(CONFIG_ENV_SCSI_PART_USE_HW)
+	if (blk_get_device_part_str("scsi", CONFIG_ENV_SCSI_HW_PARTITION,
+				    &ep->blk, &ep->part, true))
+		return NULL;
+#endif
 
 	ep->count = CONFIG_ENV_SIZE / ep->part.blksz;
 
@@ -95,20 +100,24 @@ static int env_scsi_load(void)
 	int ret;
 
 	if (!ep) {
-		if (CONFIG_ENV_SCSI_PART_UUID[0] == '\0')
-			env_set_default("SCSI partition " CONFIG_ENV_SCSI_HW_PARTITION " not found", 0);
-		else
-			env_set_default(CONFIG_ENV_SCSI_PART_UUID " partition not found", 0);
-
+#if defined(CONFIG_ENV_SCSI_PART_USE_TYPE_GUID)
+		env_set_default(CONFIG_ENV_SCSI_PART_TYPE_GUID " partition not found", 0);
+#elif defined(CONFIG_ENV_SCSI_PART_USE_UUID)
+		env_set_default(CONFIG_ENV_SCSI_PART_UUID " partition not found", 0);
+#elif defined(CONFIG_ENV_SCSI_PART_USE_HW)
+		env_set_default("SCSI partition " CONFIG_ENV_SCSI_HW_PARTITION " not found", 0);
+#endif
 		return -ENOENT;
 	}
 
 	if (blk_dread(ep->blk, ep->part.start, ep->count, &envbuf) != ep->count) {
-		if (CONFIG_ENV_SCSI_PART_UUID[0] == '\0')
-			env_set_default("SCSI partition " CONFIG_ENV_SCSI_HW_PARTITION " read failed", 0);
-		else
-			env_set_default(CONFIG_ENV_SCSI_PART_UUID " partition read failed", 0);
-
+#if defined(CONFIG_ENV_SCSI_PART_USE_TYPE_GUID)
+		env_set_default(CONFIG_ENV_SCSI_PART_TYPE_GUID " partition read failed", 0);
+#elif defined(CONFIG_ENV_SCSI_PART_USE_UUID)
+		env_set_default(CONFIG_ENV_SCSI_PART_UUID " partition read failed", 0);
+#elif defined(CONFIG_ENV_SCSI_PART_USE_HW)
+		env_set_default("SCSI partition " CONFIG_ENV_SCSI_HW_PARTITION " read failed", 0);
+#endif
 		return -EIO;
 	}
 

-- 
2.34.1