[PATCH 6/6] board: phytec: common: k3: Apply SoM-specific overlays to OS device tree

[Wadim Egorov]

Our SoMs are available in multiple configurations, managed via device
tree overlays. To determine the specific variant in use, we read the
EEPROM and apply the appropriate overlays during boot to the device tree
used by the OS.

Signed-off-by: Wadim Egorov <w.egorov at phytec.de>
---
 board/phytec/common/k3/board.c | 73 ++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/board/phytec/common/k3/board.c b/board/phytec/common/k3/board.c
index 3d7e090ccaa..346b2b6491a 100644
--- a/board/phytec/common/k3/board.c
+++ b/board/phytec/common/k3/board.c
@@ -6,7 +6,9 @@
 
 #include <env_internal.h>
 #include <fdt_support.h>
+#include <dm/ofnode.h>
 #include <spl.h>
+#include <malloc.h>
 #include <asm/arch/hardware.h>
 
 #include "../am6_som_detection.h"
@@ -97,8 +99,79 @@ int board_late_init(void)
 #endif
 
 #if IS_ENABLED(CONFIG_OF_LIBFDT) && IS_ENABLED(CONFIG_OF_BOARD_SETUP)
+static int fdt_apply_overlay_from_fit(const char *overlay_path, void *fdt)
+{
+	u64 loadaddr;
+	ofnode node;
+	int ret;
+
+	node = ofnode_path(overlay_path);
+	if (!ofnode_valid(node))
+		return -FDT_ERR_NOTFOUND;
+
+	ret = ofnode_read_u64(node, "load", &loadaddr);
+	if (ret)
+		return ret;
+
+	return fdt_overlay_apply_verbose(fdt, (void *)loadaddr);
+}
+
+static void fdt_apply_som_overlays(void *blob)
+{
+	void *fdt_copy;
+	u32 fdt_size;
+	struct phytec_eeprom_data data;
+	int err;
+
+	fdt_size = fdt_totalsize(blob);
+	fdt_copy = malloc(fdt_size);
+	if (!fdt_copy)
+		goto fixup_error;
+
+	memcpy(fdt_copy, blob, fdt_size);
+
+	err = phytec_eeprom_data_setup(&data, 0, EEPROM_ADDR);
+	if (err)
+		goto fixup_error;
+
+	if (phytec_get_am6_rtc(&data) == 0) {
+		err = fdt_apply_overlay_from_fit("/fit-images/som-no-rtc", fdt_copy);
+		if (err)
+			goto fixup_error;
+	}
+
+	if (phytec_get_am6_spi(&data) == PHYTEC_EEPROM_VALUE_X) {
+		err = fdt_apply_overlay_from_fit("/fit-images/som-no-spi", fdt_copy);
+		if (err)
+			goto fixup_error;
+	}
+
+	if (phytec_get_am6_eth(&data) == 0) {
+		err = fdt_apply_overlay_from_fit("/fit-images/som-no-eth", fdt_copy);
+		if (err)
+			goto fixup_error;
+	}
+
+	if (phytec_am6_is_qspi(&data)) {
+		err = fdt_apply_overlay_from_fit("/fit-images/som-qspi-nor", fdt_copy);
+		if (err)
+			goto fixup_error;
+	}
+
+	memcpy(blob, fdt_copy, fdt_size);
+
+cleanup:
+	free(fdt_copy);
+	return;
+
+fixup_error:
+	pr_err("Failed to apply SoM overlays\n");
+	goto cleanup;
+}
+
 int ft_board_setup(void *blob, struct bd_info *bd)
 {
+	fdt_apply_som_overlays(blob);
 	fdt_copy_fixed_partitions(blob);
 
 	return 0;
-- 
2.34.1