From: Aurelien Jarno <aurelien@aurel32.net>
To: linux-kernel@vger.kernel.org
Cc: Aurelien Jarno <aurelien@aurel32.net>,
Arnd Bergmann <arnd@arndb.de>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Olof Johansson <olof@lixom.net>, Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-rpi-kernel@lists.infradead.org, soc@kernel.org
Subject: [PATCH 1/2] arm64: dts: broadcom: Enable device-tree overlay support for RPi devices
Date: Mon, 11 Apr 2022 00:59:39 +0200 [thread overview]
Message-ID: <20220410225940.135744-2-aurelien@aurel32.net> (raw)
In-Reply-To: <20220410225940.135744-1-aurelien@aurel32.net>
Add the '-@' DTC option for the Raspberry Pi devices. This option
populates the '__symbols__' node that contains all the necessary symbols
for supporting device-tree overlays (for instance from the firmware or
the bootloader) on these devices.
The Rasbperry Pi devices are well known for their GPIO header, that
allow various "HATs" or other modules do be connected and this enables
users to create out-of-tree device-tree overlays for these modules.
Please note that this change does increase the size of the resulting DTB
by ~40%. For example, with v5.17 increase in size is as follows:
bcm2711-rpi-400.dtb 26481 -> 36830 bytes
bcm2711-rpi-4-b.dtb 26537 -> 36886 bytes
bcm2711-rpi-cm4-io.dtb 26426 -> 36945 bytes
bcm2837-rpi-3-a-plus.dtb 14133 -> 19740 bytes
bcm2837-rpi-3-b.dtb 14310 -> 20006 bytes
bcm2837-rpi-3-b-plus.dtb 14670 -> 20474 bytes
bcm2837-rpi-cm3-io3.dtb 13680 -> 19266 bytes
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
arch/arm64/boot/dts/broadcom/Makefile | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile
index 5082fcd1fea5..0aa8ee2afdd5 100644
--- a/arch/arm64/boot/dts/broadcom/Makefile
+++ b/arch/arm64/boot/dts/broadcom/Makefile
@@ -1,4 +1,15 @@
# SPDX-License-Identifier: GPL-2.0
+
+# Enables support for device-tree overlays
+DTC_FLAGS_bcm2711-rpi-400 := -@
+DTC_FLAGS_bcm2711-rpi-4-b := -@
+DTC_FLAGS_bcm2711-rpi-cm4-io := -@
+DTC_FLAGS_bcm2837-rpi-3-a-plus := -@
+DTC_FLAGS_bcm2837-rpi-3-b := -@
+DTC_FLAGS_bcm2837-rpi-3-b-plus := -@
+DTC_FLAGS_bcm2837-rpi-cm3-io3 := -@
+DTC_FLAGS_bcm2837-rpi-zero-2-w := -@
+
dtb-$(CONFIG_ARCH_BCM2835) += bcm2711-rpi-400.dtb \
bcm2711-rpi-4-b.dtb \
bcm2711-rpi-cm4-io.dtb \
--
2.34.1
next prev parent reply other threads:[~2022-04-10 23:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-10 22:59 [PATCH 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices Aurelien Jarno
2022-04-10 22:59 ` Aurelien Jarno [this message]
2023-05-25 7:36 ` [PATCH 1/2] arm64: dts: broadcom: " Uwe Kleine-König
2022-04-10 22:59 ` [PATCH 2/2] arm: dts: " Aurelien Jarno
2023-05-22 6:22 ` [PATCH 0/2] arm/arm64: " Uwe Kleine-König
2023-05-30 17:56 [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees Uwe Kleine-König
2023-05-30 17:56 ` [PATCH 1/2] arm64: dts: broadcom: Enable device-tree overlay support for RPi devices Uwe Kleine-König
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