Current board DTS for Raspberry Pi5 states that bcm2712-rpi-5-b.dts
should not be modified and all declarations should go in the overlay
board DTS instead (bcm2712-rpi-5-b-ovl-rp1.dts).
There's a caveat though: there's currently no infrastructure to reliably
reference nodes that have not been declared yet, as is the case when
loading those nodes from a runtime overlay. For more details about
these limitations see [1] and follow-ups.
Change the comment to make it clear which DTS file will host specific
nodes, especially the RP1 related nodes which should be customized
outside the overlay DTS.
Link
[1] - https://lore.kernel.org/all/CAMEGJJ3=W8_R0xBvm8r+Q7iExZx8xPBHEWWGAT9ngpGWDSKCaQ@mail.gmail.com/
Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
---
arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts
index adad85e68f1b..865f092608a6 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts
+++ b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts
@@ -4,8 +4,14 @@
* the RP1 driver to load the RP1 dtb overlay at runtime, while
* bcm2712-rpi-5-b.dts (this file) is the fully defined one (i.e. it
* already contains RP1 node, so no overlay is loaded nor needed).
- * This file is not intended to be modified, nodes should be added
- * to the included bcm2712-rpi-5-b-ovl-rp1.dts.
+ * This file is intended to host the override nodes for the RP1 peripherals,
+ * e.g. to declare the phy of the ethernet interface or the custom pin setup
+ * for several RP1 peripherals.
+ * This in turn is due to the fact that there's no current generic
+ * infrastructure to reference nodes (i.e. the nodes in rp1-common.dtsi) that
+ * are not yet defined in the DT since they are loaded at runtime via overlay.
+ * All other nodes that do not have anything to do with RP1 should be added
+ * to the included bcm2712-rpi-5-b-ovl-rp1.dts instead.
*/
/dts-v1/;
--
2.35.3
From: Florian Fainelli <f.fainelli@gmail.com> On Mon, 11 Aug 2025 16:12:35 +0200, Andrea della Porta <andrea.porta@suse.com> wrote: > Current board DTS for Raspberry Pi5 states that bcm2712-rpi-5-b.dts > should not be modified and all declarations should go in the overlay > board DTS instead (bcm2712-rpi-5-b-ovl-rp1.dts). > > There's a caveat though: there's currently no infrastructure to reliably > reference nodes that have not been declared yet, as is the case when > loading those nodes from a runtime overlay. For more details about > these limitations see [1] and follow-ups. > > Change the comment to make it clear which DTS file will host specific > nodes, especially the RP1 related nodes which should be customized > outside the overlay DTS. > > Link > [1] - https://lore.kernel.org/all/CAMEGJJ3=W8_R0xBvm8r+Q7iExZx8xPBHEWWGAT9ngpGWDSKCaQ@mail.gmail.com/ > > Signed-off-by: Andrea della Porta <andrea.porta@suse.com> > --- Applied to https://github.com/Broadcom/stblinux/commits/devicetree-arm64/next, thanks! -- Florian
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