ARM: renesas: Configure DRAM size from ATF DT fragment

The ATF can pass additional information via the first four registers,
x0...x3. The R-Car Gen3 with mainline ATF, register x1 contains pointer
to a device tree with platform information. Parse this device tree and
extract DRAM size information from it. This is useful on systems where
the DRAM size can vary between configurations.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

1 files changed, 24 insertions, 4 deletions

diff --git a/board/renesas/salvator-x/salvator-x.c b/board/renesas/salvator-x/salvator-x.c
index 8f0247e0461..1db08fce6a2 100644
--- a/board/renesas/salvator-x/salvator-x.c
+++ b/board/renesas/salvator-x/salvator-x.c
@@ -69,17 +69,37 @@ int board_init(void)
 	return 0;
 }
 
+/*
+ * If the firmware passed a device tree use it for U-Boot DRAM setup.
+ */
+extern u64 rcar_atf_boot_args[];
+
 int dram_init(void)
 {
-	if (fdtdec_setup_mem_size_base() != 0)
-		return -EINVAL;
+	const void *atf_fdt_blob = (const void *)(rcar_atf_boot_args[1]);
+	const void *blob;
 
-	return 0;
+	/* Check if ATF passed us DTB. If not, fall back to builtin DTB. */
+	if (fdt_magic(atf_fdt_blob) == FDT_MAGIC)
+		blob = atf_fdt_blob;
+	else
+		blob = gd->fdt_blob;
+
+	return fdtdec_setup_mem_size_base_fdt(blob);
 }
 
 int dram_init_banksize(void)
 {
-	fdtdec_setup_memory_banksize();
+	const void *atf_fdt_blob = (const void *)(rcar_atf_boot_args[1]);
+	const void *blob;
+
+	/* Check if ATF passed us DTB. If not, fall back to builtin DTB. */
+	if (fdt_magic(atf_fdt_blob) == FDT_MAGIC)
+		blob = atf_fdt_blob;
+	else
+		blob = gd->fdt_blob;
+
+	fdtdec_setup_memory_banksize_fdt(blob);
 
 	return 0;
 }