[RFC PATCH v2 4/5] arm64: dts: google: lga: Add lga.fitconfig FIT configuration file

[Douglas Anderson]

Add a FIT configuration file (`lga.fitconfig`) listing the Google Tensor
G5 (LGA) Pixel 10 family boards (`lga-blazer.dtb`, `lga-frankel.dtb`,
and `lga-mustang.dtb`) along with board and SoC ID/revision metadata in
each configuration's `match-1` subnode [1], allowing the LGA FIT image
to be built with:

  make \
    FIT_CONFIG=google/lga.fitconfig \
    FIT_COMPRESSION=none \
    FIT_FACTOR_DTBS=1 \
    FDTFACTOR_ARGS="--strip-local-fixups --single-base-dtb" \
    image.fit

NOTE: At the moment, Pixel 10 doesn't directly boot from a FIT
image. However, packaging scripts will be able to take an image as
built above and convert it into a format that the bootloader can
handle.

Each configuration carries a `match-1` subnode (`compatible =
"google,board-id"`) with typed `board-id`, `board-rev`, `soc-id`, and
`soc-rev` properties [1] to identify which configuration to use on which
board without polluting the device trees themselves with loader
metadata. Having a structured (and upstream) place to store this data is
part of the motivation for landing this FIT configuration file.

Side note: at the moment, the Pixel bootloader can't handle picking
overlays based on the `soc-id` and `soc-rev` (it only uses those to pick
base dtb files), so for now we won't be able to support boards that
might have different SoCs. I've included the `soc-id` and `soc-rev` in
this FIT configuration in the hopes that we can improve the bootloader
in the future, though.

[1] https://github.com/open-source-firmware/flat-image-tree/pull/66

Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Changes in v2:
- Replace checked-in lga.its with a compact lga.fitconfig sidecar file
  consumed by scripts/make_fit.py (Simon Glass)
- Move board/SoC matching metadata from the configuration description
  string to a typed match-1 subnode per the proposed FIT spec extension
  (Simon Glass)

 arch/arm64/boot/dts/google/lga.fitconfig | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 arch/arm64/boot/dts/google/lga.fitconfig

diff --git a/arch/arm64/boot/dts/google/lga.fitconfig b/arch/arm64/boot/dts/google/lga.fitconfig
new file mode 100644
index 000000000000..fd90b85c2fb6
--- /dev/null
+++ b/arch/arm64/boot/dts/google/lga.fitconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+[lga-blazer.dtb]
+match-1/compatible = google,board-id
+match-1/board-id = 0x070406
+match-1/board-rev = 0x010000
+match-1/soc-id = 0x0005
+match-1/soc-rev = 0x010000
+
+[lga-frankel.dtb]
+match-1/compatible = google,board-id
+match-1/board-id = 0x070306
+match-1/board-rev = 0x010000
+match-1/soc-id = 0x0005
+match-1/soc-rev = 0x010000
+
+[lga-mustang.dtb]
+match-1/compatible = google,board-id
+match-1/board-id = 0x070506
+match-1/board-rev = 0x010000
+match-1/soc-id = 0x0005
+match-1/soc-rev = 0x010000
-- 
2.56.0.611.g1030f0b940-goog