As the Renesas Reduced Pin Count Interface may be locked by TF-A, it is
disabled by default[1]. When unlocked, TF-A passes a DT fragment to
enable it, which is applied to the U-Boot DT[2].
Unlike the memory layout, the RPC-IF enablement is not propagated to
subsequent software. Hence e.g. Linux cannot know if the RPC-IF is
locked or not, and will lock-up when trying to access the RPC-IF when
locked.
Fix this by checking if the RPC-IF is enabled in the TF-A DT fragment, and
setting the status of the RPC-IF device node in the target DT, if
present, to "okay". Do this only when a "flash" subnode is found, to
avoid errors in subsequent software when the RPC-IF is not intended to
be used.
Note that this requires the status of the RPC-IF node to be set to
"disabled" in the target DT, just like in the U-Boot DT.
[1] commit 3d5f45c95c9db73d ("ARM: dts: rmobile: Disable RPC HF by
default")
[2] commit 361377dbdbc9f0f5 ("ARM: rmobile: Merge prior-stage firmware
DT fragment into U-Boot DT on Gen3")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
board/renesas/rcar-common/common.c | 46 ++++++++++++++++++++++++++++--
1 file changed, 44 insertions(+), 2 deletions(-)
diff --git a/board/renesas/rcar-common/common.c b/board/renesas/rcar-common/common.c
index 0352d341e757bed9..daa1beb14f807800 100644
--- a/board/renesas/rcar-common/common.c
+++ b/board/renesas/rcar-common/common.c
@@ -9,6 +9,7 @@
#include <common.h>
#include <dm.h>
+#include <fdt_support.h>
#include <init.h>
#include <asm/global_data.h>
#include <dm/uclass-internal.h>
@@ -19,9 +20,11 @@
DECLARE_GLOBAL_DATA_PTR;
-/* If the firmware passed a device tree use it for U-Boot DRAM setup. */
+/* If the firmware passed a device tree use it for e.g. U-Boot DRAM setup. */
extern u64 rcar_atf_boot_args[];
+#define FDT_RPC_PATH "/soc/spi@ee200000"
+
int fdtdec_board_setup(const void *fdt_blob)
{
void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
@@ -81,7 +84,7 @@ static int is_mem_overlap(void *blob, int first_mem_node, int curr_mem_node)
return 0;
}
-int ft_board_setup(void *blob, struct bd_info *bd)
+static void scrub_duplicate_memory(void *blob)
{
/*
* Scrub duplicate /memory@* node entries here. Some R-Car DTs might
@@ -119,6 +122,45 @@ int ft_board_setup(void *blob, struct bd_info *bd)
first_mem_node = 0;
mem = 0;
}
+}
+
+static void update_rpc_status(void *blob)
+{
+ void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
+ int offset, enabled;
+
+ /*
+ * Check if the DT fragment received from TF-A had its RPC-IF device node
+ * enabled.
+ */
+ if (fdt_magic(atf_fdt_blob) != FDT_MAGIC)
+ return;
+
+ offset = fdt_path_offset(atf_fdt_blob, FDT_RPC_PATH);
+ if (offset < 0)
+ return;
+
+ enabled = fdtdec_get_is_enabled(atf_fdt_blob, offset);
+ if (!enabled)
+ return;
+
+ /*
+ * Find the RPC-IF device node, and enable it if it has a flash subnode.
+ */
+ offset = fdt_path_offset(blob, FDT_RPC_PATH);
+ if (offset < 0)
+ return;
+
+ if (fdt_subnode_offset(blob, offset, "flash") < 0)
+ return;
+
+ fdt_status_okay(blob, offset);
+}
+
+int ft_board_setup(void *blob, struct bd_info *bd)
+{
+ scrub_duplicate_memory(blob);
+ update_rpc_status(blob);
return 0;
}
--
2.25.1
