[RFC PATCH] dts: automatically build necessary .dtb files

[Rasmus Villemoes]

When building for a custom board, it is quite common to maintain a
private branch which include some defconfig and .dts files. But to
hook up those .dts files requires modifying a file "belonging" to
upstream U-Boot, the arch/*/dts/Makefile. Forward-porting that branch
to a newer upstream then often results in a conflict which, while it
is trivial to resolve by hand, makes it harder to have a CI do "try to
build our board against latest upstream".

The .config usually includes information on precisely what .dtb(s) are
needed, so to avoid having to modify the Makefile, simply add the
files in (SPL_)OF_LIST to dtb-y.

A technicality is that (SPL_)OF_LIST is not always defined, so rework
the Kconfig symbols so that (SPL_)OF_LIST is always defined (when
(SPL_)OF_CONTROL), but only prompted for in the cases which used to be
their "depends on".

nios2 and microblaze already have something like this in their
dts/Makefile, and the rationale in commit 41f59f68539 is similar to
the above. So this simply generalizes existing practice. Followup
patches could remove the logic in those two makefiles, just as there's
potential for moving some common boilerplate from all the
arch/*/dts/Makefile files to the new scripts/Makefile.dts.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
 arch/arc/dts/Makefile        | 2 ++
 arch/arm/dts/Makefile        | 2 ++
 arch/m68k/dts/Makefile       | 2 ++
 arch/microblaze/dts/Makefile | 2 ++
 arch/mips/dts/Makefile       | 2 ++
 arch/nds32/dts/Makefile      | 2 ++
 arch/nios2/dts/Makefile      | 2 ++
 arch/powerpc/dts/Makefile    | 2 ++
 arch/riscv/dts/Makefile      | 2 ++
 arch/sandbox/dts/Makefile    | 2 ++
 arch/sh/dts/Makefile         | 2 ++
 arch/x86/dts/Makefile        | 2 ++
 arch/xtensa/dts/Makefile     | 2 ++
 dts/Kconfig                  | 8 ++++----
 scripts/Makefile.dts         | 3 +++
 15 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 scripts/Makefile.dts

diff --git a/arch/arc/dts/Makefile b/arch/arc/dts/Makefile
index 515fe1fe53..532a8131c5 100644
--- a/arch/arc/dts/Makefile
+++ b/arch/arc/dts/Makefile
@@ -8,6 +8,8 @@ dtb-$(CONFIG_TARGET_EMSDP) +=  emsdp.dtb
 dtb-$(CONFIG_TARGET_HSDK) +=  hsdk.dtb hsdk-4xd.dtb
 dtb-$(CONFIG_TARGET_IOT_DEVKIT) +=  iot_devkit.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index b3e2a9c9d7..ef58be0381 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -1163,6 +1163,8 @@ dtb-$(CONFIG_TARGET_IMX8MM_CL_IOT_GATE_OPTEE) += imx8mm-cl-iot-gate-optee.dtb
 
 dtb-$(CONFIG_TARGET_EA_LPC3250DEVKITV2) += lpc3250-ea3250.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 # Add any required device tree compiler flags here
diff --git a/arch/m68k/dts/Makefile b/arch/m68k/dts/Makefile
index fdd435bc34..7988522eb9 100644
--- a/arch/m68k/dts/Makefile
+++ b/arch/m68k/dts/Makefile
@@ -18,6 +18,8 @@ dtb-$(CONFIG_TARGET_M5373EVB) += M5373EVB.dtb
 dtb-$(CONFIG_TARGET_AMCORE) += amcore.dtb
 dtb-$(CONFIG_TARGET_STMARK2) += stmark2.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/microblaze/dts/Makefile b/arch/microblaze/dts/Makefile
index 4690dc1b9f..427a8f9aac 100644
--- a/arch/microblaze/dts/Makefile
+++ b/arch/microblaze/dts/Makefile
@@ -2,6 +2,8 @@
 
 dtb-y += $(shell echo $(CONFIG_DEFAULT_DEVICE_TREE)).dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/mips/dts/Makefile b/arch/mips/dts/Makefile
index 215283cfa0..95144b24dc 100644
--- a/arch/mips/dts/Makefile
+++ b/arch/mips/dts/Makefile
@@ -34,6 +34,8 @@ dtb-$(CONFIG_SOC_JR2) += jr2_pcb110.dtb jr2_pcb111.dtb serval2_pcb112.dtb
 dtb-$(CONFIG_SOC_SERVALT) += servalt_pcb116.dtb
 dtb-$(CONFIG_SOC_SERVAL) += serval_pcb105.dtb serval_pcb106.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 # Add any required device tree compiler flags here
diff --git a/arch/nds32/dts/Makefile b/arch/nds32/dts/Makefile
index a8e23ad9ad..5a09e3b45b 100644
--- a/arch/nds32/dts/Makefile
+++ b/arch/nds32/dts/Makefile
@@ -2,6 +2,8 @@
 
 dtb-$(CONFIG_TARGET_ADP_AG101P) += ag101p.dtb
 dtb-$(CONFIG_TARGET_ADP_AE3XX) += ae3xx.dtb
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/nios2/dts/Makefile b/arch/nios2/dts/Makefile
index 0014acfdfb..2b29fa90f6 100644
--- a/arch/nios2/dts/Makefile
+++ b/arch/nios2/dts/Makefile
@@ -2,6 +2,8 @@
 
 dtb-y += $(CONFIG_DEFAULT_DEVICE_TREE:"%"=%).dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/powerpc/dts/Makefile b/arch/powerpc/dts/Makefile
index ceaa8ce5c8..6f0e4d69f2 100644
--- a/arch/powerpc/dts/Makefile
+++ b/arch/powerpc/dts/Makefile
@@ -29,6 +29,8 @@ dtb-$(CONFIG_TARGET_TUXX1) += kmtuxa1.dtb
 dtb-$(CONFIG_TARGET_MCR3000) += mcr3000.dtb
 dtb-$(CONFIG_TARGET_GAZERBEAM) += gazerbeam.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 # Add any required device tree compiler flags here
diff --git a/arch/riscv/dts/Makefile b/arch/riscv/dts/Makefile
index b6e9166767..45b6381139 100644
--- a/arch/riscv/dts/Makefile
+++ b/arch/riscv/dts/Makefile
@@ -8,6 +8,8 @@ dtb-$(CONFIG_TARGET_SIFIVE_UNLEASHED) += hifive-unleashed-a00.dtb
 dtb-$(CONFIG_TARGET_SIFIVE_UNMATCHED) += hifive-unmatched-a00.dtb
 dtb-$(CONFIG_TARGET_SIPEED_MAIX) += k210-maix-bit.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/sandbox/dts/Makefile b/arch/sandbox/dts/Makefile
index 3e5dc67d53..6cbc9bbcaa 100644
--- a/arch/sandbox/dts/Makefile
+++ b/arch/sandbox/dts/Makefile
@@ -8,6 +8,8 @@ endif
 dtb-$(CONFIG_UT_DM) += test.dtb
 dtb-$(CONFIG_CMD_EXTENSION) += overlay0.dtbo overlay1.dtbo
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/sh/dts/Makefile b/arch/sh/dts/Makefile
index e423bfd566..144fd3e7d2 100644
--- a/arch/sh/dts/Makefile
+++ b/arch/sh/dts/Makefile
@@ -1,5 +1,7 @@
 dtb-y += sh7751-r2dplus.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 # Add any required device tree compiler flags here
diff --git a/arch/x86/dts/Makefile b/arch/x86/dts/Makefile
index be209aaaf8..8c1c366546 100644
--- a/arch/x86/dts/Makefile
+++ b/arch/x86/dts/Makefile
@@ -22,6 +22,8 @@ dtb-y += bayleybay.dtb \
 	slimbootloader.dtb \
 	baytrail_som-db5800-som-6867.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS += -R 4 -p 0x1000
diff --git a/arch/xtensa/dts/Makefile b/arch/xtensa/dts/Makefile
index 06ee25d2da..fbbdefaf2c 100644
--- a/arch/xtensa/dts/Makefile
+++ b/arch/xtensa/dts/Makefile
@@ -2,6 +2,8 @@
 
 dtb-$(CONFIG_XTFPGA) += ml605.dtb ml605_nommu.dtb kc705.dtb kc705_nommu.dtb
 
+include $(srctree)/scripts/Makefile.dts
+
 targets += $(dtb-y)
 
 DTC_FLAGS +=
diff --git a/dts/Kconfig b/dts/Kconfig
index b7c4a2fec0..446d709715 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -132,8 +132,8 @@ config DEFAULT_DEVICE_TREE
 	  $ make DEVICE_TREE=<device-tree-name>
 
 config OF_LIST
-	string "List of device tree files to include for DT control"
-	depends on SPL_LOAD_FIT || MULTI_DTB_FIT
+	string "List of device tree files to include for DT control" if SPL_LOAD_FIT || MULTI_DTB_FIT
+	depends on OF_CONTROL
 	default DEFAULT_DEVICE_TREE
 	help
 	  This option specifies a list of device tree files to use for DT
@@ -240,8 +240,8 @@ config SPL_MULTI_DTB_FIT
 	  capabilities, pad configurations).
 
 config SPL_OF_LIST
-	string "List of device tree files to include for DT control in SPL"
-	depends on SPL_MULTI_DTB_FIT
+	string "List of device tree files to include for DT control in SPL" if SPL_MULTI_DTB_FIT
+	depends on SPL_OF_CONTROL
 	default OF_LIST
 	help
 	  This option specifies a list of device tree files to use for DT
diff --git a/scripts/Makefile.dts b/scripts/Makefile.dts
new file mode 100644
index 0000000000..2561025da8
--- /dev/null
+++ b/scripts/Makefile.dts
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+dtb-y += $(patsubst %,%.dtb,$(subst ",,$(CONFIG_$(SPL_)OF_LIST)))
-- 
2.31.1