[PATCH 1/2] lib: utils: Implement "ranges" property parsing

[Atish Patra]

The "reg" property in a device node may not be the correct address always.
If a parent node defines a "ranges" property, the child address need to be
translated with respect to parents address. If the ranges property is not
present, it will just use 1:1 translation.

Signed-off-by: Atish Patra <atish.patra at wdc.com>
---
 lib/utils/fdt/fdt_helper.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
index aec73a0598d7..8e1d1800d4de 100644
--- a/lib/utils/fdt/fdt_helper.c
+++ b/lib/utils/fdt/fdt_helper.c
@@ -74,10 +74,10 @@ int fdt_find_match(void *fdt, int startoff,
 int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
 			   unsigned long *size)
 {
-	int parent, len, i;
+	int parent, len, i, rlen;
 	int cell_addr, cell_size;
-	const fdt32_t *prop_addr, *prop_size;
-	uint64_t temp = 0;
+	const fdt32_t *prop_addr, *prop_size, *ranges;
+	uint64_t temp = 0, offset = 0, caddr = 0, paddr = 0, rsize = 0;
 
 	parent = fdt_parent_offset(fdt, node);
 	if (parent < 0)
@@ -98,7 +98,24 @@ int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
 	if (addr) {
 		for (i = 0; i < cell_addr; i++)
 			temp = (temp << 32) | fdt32_to_cpu(*prop_addr++);
-		*addr = temp;
+		ranges = fdt_getprop(fdt, parent, "ranges", &rlen);
+		if (ranges && rlen > 0) {
+			for (i = 0; i < cell_addr; i++)
+				caddr = (caddr << 32) | fdt32_to_cpu(*ranges++);
+			for (i = 0; i < cell_addr; i++)
+				paddr = (paddr << 32) | fdt32_to_cpu(*ranges++);
+			for (i = 0; i < cell_size; i++)
+				rsize = (rsize << 32) | fdt32_to_cpu(*ranges++);
+			if (temp < caddr || caddr >= (temp + rsize )) {
+				sbi_dprintf("invalid address translation reg [%lx] : ca [%lx]\n",temp, caddr);
+				return SBI_ENODEV;
+			}
+			offset = temp - caddr;
+			*addr = paddr + offset;
+		} else {
+			/* No translation required */
+			*addr = temp;
+		}
 	}
 	temp = 0;
 
-- 
2.25.1