lib: uuid: introduce uuid_str_to_le_bin function

convert UUID string to little endian binary data

Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jens Wiklander <jens.wiklander@linaro.org>

lib/uuid.c

@@ -1,6 +1,10 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright 2011 Calxeda, Inc.
+ * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ *
+ * Authors:
+ *   Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
  */
 
 #include <common.h>
@@ -354,6 +358,50 @@ int uuid_str_to_bin(const char *uuid_str, unsigned char *uuid_bin,
 	return 0;
 }
 
+/**
+ * uuid_str_to_le_bin() - Convert string UUID to little endian binary data.
+ * @uuid_str:	pointer to UUID string
+ * @uuid_bin:	pointer to allocated array for little endian output [16B]
+ *
+ * UUID string is 36 characters (36 bytes):
+ *
+ * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+ *
+ * where x is a hexadecimal character. Fields are separated by '-'s.
+ * When converting to a little endian binary UUID, the string fields are reversed.
+ *
+ * Return:
+ *
+ *    uuid_bin filled with little endian UUID data
+ *    On success 0 is returned. Otherwise, failure code.
+ */
+int uuid_str_to_le_bin(const char *uuid_str, unsigned char *uuid_bin)
+{
+	u16 tmp16;
+	u32 tmp32;
+	u64 tmp64;
+
+	if (!uuid_str_valid(uuid_str) || !uuid_bin)
+		return -EINVAL;
+
+	tmp32 = cpu_to_le32(hextoul(uuid_str, NULL));
+	memcpy(uuid_bin, &tmp32, 4);
+
+	tmp16 = cpu_to_le16(hextoul(uuid_str + 9, NULL));
+	memcpy(uuid_bin + 4, &tmp16, 2);
+
+	tmp16 = cpu_to_le16(hextoul(uuid_str + 14, NULL));
+	memcpy(uuid_bin + 6, &tmp16, 2);
+
+	tmp16 = cpu_to_le16(hextoul(uuid_str + 19, NULL));
+	memcpy(uuid_bin + 8, &tmp16, 2);
+
+	tmp64 = cpu_to_le64(simple_strtoull(uuid_str + 24, NULL, 16));
+	memcpy(uuid_bin + 10, &tmp64, 6);
+
+	return 0;
+}
+
 /*
  * uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
  *