SPL: Add FIT data-position property support

For external data, FIT has a optional property "data-position" which
can set the external data to a fixed offset to FIT beginning.
Add the support for this property in SPL FIT.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tomas Melin <tomas.melin@vaisala.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: "Andrew F. Davis" <afd@ti.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: "tomas.melin@vaisala.com" <tomas.melin@vaisala.com>
Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Lokesh Vutla <lokeshvutla@ti.com>
Cc: "Cooper Jr., Franklin" <fcooper@ti.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Cc: Jean-Jacques Hiblot <jjhiblot@ti.com>
Cc: Rick Altherr <raltherr@google.com>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/common/image-fit.c b/common/image-fit.c
index 7f17fd1..b785d8a 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -807,6 +807,31 @@
 }
 
 /**
+ * Get 'data-position' property from a given image node.
+ *
+ * @fit: pointer to the FIT image header
+ * @noffset: component image node offset
+ * @data_position: holds the data-position property
+ *
+ * returns:
+ *     0, on success
+ *     -ENOENT if the property could not be found
+ */
+int fit_image_get_data_position(const void *fit, int noffset,
+				int *data_position)
+{
+	const fdt32_t *val;
+
+	val = fdt_getprop(fit, noffset, FIT_DATA_POSITION_PROP, NULL);
+	if (!val)
+		return -ENOENT;
+
+	*data_position = fdt32_to_cpu(*val);
+
+	return 0;
+}
+
+/**
  * Get 'data-size' property from a given image node.
  *
  * @fit: pointer to the FIT image header
diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c
index 72ae8f4..cc07fbc 100644
--- a/common/spl/spl_fit.c
+++ b/common/spl/spl_fit.c
@@ -173,6 +173,7 @@
 	int align_len = ARCH_DMA_MINALIGN - 1;
 	uint8_t image_comp = -1, type = -1;
 	const void *data;
+	bool external_data = false;
 
 	if (IS_ENABLED(CONFIG_SPL_OS_BOOT) && IS_ENABLED(CONFIG_SPL_GZIP)) {
 		if (fit_image_get_comp(fit, node, &image_comp))
@@ -189,9 +190,15 @@
 	if (fit_image_get_load(fit, node, &load_addr))
 		load_addr = image_info->load_addr;
 
-	if (!fit_image_get_data_offset(fit, node, &offset)) {
-		/* External data */
+	if (!fit_image_get_data_position(fit, node, &offset)) {
+		external_data = true;
+	} else if (!fit_image_get_data_offset(fit, node, &offset)) {
 		offset += base_offset;
+		external_data = true;
+	}
+
+	if (external_data) {
+		/* External data */
 		if (fit_image_get_data_size(fit, node, &len))
 			return -ENOENT;
 
diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index 6f727a1..88663a1 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -288,7 +288,8 @@
 
 The 'data-offset' property can be substituted with 'data-position', which
 defines an absolute position or address as the offset. This is helpful when
-booting U-Boot proper before performing relocation.
+booting U-Boot proper before performing relocation. Pass '-p [offset]' to
+mkimage to enable 'data-position'.
 
 Normal kernel FIT image has data embedded within FIT structure. U-Boot image
 for SPL boot has external data. Existence of 'data-offset' can be used to
diff --git a/include/image.h b/include/image.h
index e9c18ce..a128a62 100644
--- a/include/image.h
+++ b/include/image.h
@@ -887,6 +887,7 @@
 
 /* image node */
 #define FIT_DATA_PROP		"data"
+#define FIT_DATA_POSITION_PROP	"data-position"
 #define FIT_DATA_OFFSET_PROP	"data-offset"
 #define FIT_DATA_SIZE_PROP	"data-size"
 #define FIT_TIMESTAMP_PROP	"timestamp"
@@ -968,6 +969,8 @@
 int fit_image_get_data(const void *fit, int noffset,
 				const void **data, size_t *size);
 int fit_image_get_data_offset(const void *fit, int noffset, int *data_offset);
+int fit_image_get_data_position(const void *fit, int noffset,
+				int *data_position);
 int fit_image_get_data_size(const void *fit, int noffset, int *data_size);
 
 int fit_image_hash_get_algo(const void *fit, int noffset, char **algo);