[PATCH v4 1/6] boards: qemu-virt: apply overlay at postcore_initcall level

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Qemu board driver fixups should be applied very early to be able to
influence core components, even if they are controlled directly by
initcalls. For this reason, let's move the early board code into
the earliest possible initcall level.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 common/boards/qemu-virt/board.c | 51 +++++++++++++++++++--------------
 1 file changed, 29 insertions(+), 22 deletions(-)

diff --git a/common/boards/qemu-virt/board.c b/common/boards/qemu-virt/board.c
index d0f4412cdea5..19d995aa508e 100644
--- a/common/boards/qemu-virt/board.c
+++ b/common/boards/qemu-virt/board.c
@@ -36,22 +36,6 @@ static inline void arm_virt_init(void) {}
 
 extern char __dtb_overlay_of_flash_start[];
 
-static int virt_probe(struct device *dev)
-{
-	struct device_node *overlay;
-	void (*init)(void);
-
-	init = device_get_match_data(dev);
-	if (init)
-		init();
-
-	overlay = of_unflatten_dtb(__dtb_overlay_of_flash_start, INT_MAX);
-	of_overlay_apply_tree(dev->of_node, overlay);
-	/* of_probe() will happen later at of_populate_initcall */
-
-	return 0;
-}
-
 static const struct of_device_id virt_of_match[] = {
 	{ .compatible = "linux,dummy-virt", .data = arm_virt_init },
 	{ .compatible = "riscv-virtio" },
@@ -59,10 +43,33 @@ static const struct of_device_id virt_of_match[] = {
 };
 BAREBOX_DEEP_PROBE_ENABLE(virt_of_match);
 
-static struct driver virt_board_driver = {
-	.name = "board-qemu-virt",
-	.probe = virt_probe,
-	.of_compatible = virt_of_match,
-};
+/*
+ * We don't have a dedicated qemu-virt device tree and instead rely
+ * on what Qemu passes us. To be able to get fundamental changes
+ * in very early, we forego having a board driver here and do this
+ * directly in the initcall.
+ */
+static int virt_board_driver_init(void)
+{
+	struct device_node *root = of_get_root_node();
+	struct device_node *overlay;
+	const struct of_device_id *id;
+	void (*init)(void);
 
-postcore_platform_driver(virt_board_driver);
+	id = of_match_node(virt_of_match, root);
+	if (!id)
+		return 0;
+
+	if (id->data) {
+		init = id->data;
+		init();
+	}
+
+	overlay = of_unflatten_dtb(__dtb_overlay_of_flash_start, INT_MAX);
+	of_overlay_apply_tree(root, overlay);
+
+	/* of_probe() will happen later at of_populate_initcall */
+
+	return 0;
+}
+postcore_initcall(virt_board_driver_init);
-- 
2.39.2