From b3cc55f71a99a60030ad611685dff7b8ed332791 Mon Sep 17 00:00:00 2001
From: "Ivan T. Ivanov" <iivanov@suse.de>
Date: Fri, 15 Dec 2023 10:17:14 +0100
Subject: [PATCH] rpi5: Use devicetree to retrieve board revision

Firmware on RPi5 return error on board revision query
through firmware interface, but on the other hand it fills
"linux,revision" in "system" node, so use it to detect board
revision.

	system {
		linux,revision = <0xc04170>;
		linux,serial = <0x6cf44e80 0x3c533ede>;
	};

Signed-off-by: Ivan T. Ivanov <iivanov@suse.de>
---
 board/raspberrypi/rpi/rpi.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index cd823ad746..2851ebc985 100644
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -171,6 +171,11 @@ static const struct rpi_model rpi_models_new_scheme[] = {
 		DTB_DIR "bcm2711-rpi-cm4.dtb",
 		true,
 	},
+	[0x17] = {
+		"5 Model B",
+		DTB_DIR "bcm2712-rpi-5-b.dtb",
+		true,
+	},
 };
 
 static const struct rpi_model rpi_models_old_scheme[] = {
@@ -429,15 +434,27 @@ static void get_board_revision(void)
 	int ret;
 	const struct rpi_model *models;
 	uint32_t models_count;
+	ofnode node;
 
 	BCM2835_MBOX_INIT_HDR(msg);
 	BCM2835_MBOX_INIT_TAG(&msg->get_board_rev, GET_BOARD_REV);
 
 	ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg->hdr);
 	if (ret) {
-		printf("bcm2835: Could not query board revision\n");
 		/* Ignore error; not critical */
-		return;
+		node = ofnode_path("/system");
+		if (!ofnode_valid(node)) {
+			printf("bcm2835: Could not find /system node\n");
+			return;
+		}
+
+		ret = ofnode_read_u32(node, "linux,revision", &revision);
+		if (ret) {
+			printf("bcm2835: Could not find linux,revision\n");
+			return;
+		}
+	} else {
+		revision = msg->get_board_rev.body.resp.rev;
 	}
 
 	/*
@@ -451,7 +468,6 @@ static void get_board_revision(void)
 	 * http://www.raspberrypi.org/forums/viewtopic.php?f=63&t=98367&start=250
 	 * http://www.raspberrypi.org/forums/viewtopic.php?f=31&t=20594
 	 */
-	revision = msg->get_board_rev.body.resp.rev;
 	if (revision & 0x800000) {
 		rev_scheme = 1;
 		rev_type = (revision >> 4) & 0xff;