[PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Aurelien Jarno]

This patchset changes the generation of the Raspberry Pi devices DTB
files to improve the support for out-of-tree device-tree overlays, like
it has recently been done for the Nvidia SoCs.

I personally only need that for arm64, but I have added a similar patch
to do the same on arm.

Aurelien Jarno (2):
  arm64: dts: broadcom: Enable device-tree overlay support for RPi
    devices
  arm: dts: Enable device-tree overlay support for RPi devices

 arch/arm/boot/dts/Makefile            | 18 ++++++++++++++++++
 arch/arm64/boot/dts/broadcom/Makefile | 11 +++++++++++
 2 files changed, 29 insertions(+)

-- 
2.35.1

[PATCH RESEND 1/2] arm64: dts: broadcom: Enable device-tree overlay support for RPi devices

[Aurelien Jarno]

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 \
-- 
2.35.1

[PATCH RESEND 2/2] arm: dts: Enable device-tree overlay support for RPi devices

[Aurelien Jarno]

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
  bcm2835-rpi-a.dtb         12641 -> 17852 bytes
  bcm2835-rpi-a-plus.dtb    12765 -> 17976 bytes
  bcm2835-rpi-b.dtb         12763 -> 17998 bytes
  bcm2835-rpi-b-plus.dtb    12979 -> 18263 bytes
  bcm2835-rpi-b-rev2.dtb    12847 -> 18131 bytes
  bcm2835-rpi-cm1-io1.dtb   12839 -> 18113 bytes
  bcm2835-rpi-zero.dtb      12681 -> 17924 bytes
  bcm2835-rpi-zero-w.dtb    13135 -> 18430 bytes
  bcm2836-rpi-2-b.dtb       13687 -> 19255 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/arm/boot/dts/Makefile | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
index 7c16f8a2b738..85644149de44 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -81,6 +81,24 @@ dtb-$(CONFIG_SOC_SAMA7G5) += \
 	at91-sama7g5ek.dtb
 dtb-$(CONFIG_ARCH_AXXIA) += \
 	axm5516-amarillo.dtb
+# Enables support for device-tree overlays
+DTC_FLAGS_bcm2835-rpi-b := -@
+DTC_FLAGS_bcm2835-rpi-a := -@
+DTC_FLAGS_bcm2835-rpi-b-rev2 := -@
+DTC_FLAGS_bcm2835-rpi-b-plus := -@
+DTC_FLAGS_bcm2835-rpi-a-plus := -@
+DTC_FLAGS_bcm2835-rpi-cm1-io1 := -@
+DTC_FLAGS_bcm2836-rpi-2-b := -@
+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 := -@
+DTC_FLAGS_bcm2711-rpi-400 := -@
+DTC_FLAGS_bcm2711-rpi-4-b := -@
+DTC_FLAGS_bcm2711-rpi-cm4-io := -@
+DTC_FLAGS_bcm2835-rpi-zero := -@
+DTC_FLAGS_bcm2835-rpi-zero-w := -@
 dtb-$(CONFIG_ARCH_BCM2835) += \
 	bcm2835-rpi-b.dtb \
 	bcm2835-rpi-a.dtb \
-- 
2.35.1

Re: [PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Florian Fainelli]

On 4/27/2022 4:36 PM, Aurelien Jarno wrote:
> This patchset changes the generation of the Raspberry Pi devices DTB
> files to improve the support for out-of-tree device-tree overlays, like
> it has recently been done for the Nvidia SoCs.
> 
> I personally only need that for arm64, but I have added a similar patch
> to do the same on arm.

This looks good to me, Rob, does that approach work for you?
-- 
Florian

Re: [PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Aurelien Jarno]

On 2022-05-18 12:52, Florian Fainelli wrote:
> 
> 
> On 4/27/2022 4:36 PM, Aurelien Jarno wrote:
> > This patchset changes the generation of the Raspberry Pi devices DTB
> > files to improve the support for out-of-tree device-tree overlays, like
> > it has recently been done for the Nvidia SoCs.
> > 
> > I personally only need that for arm64, but I have added a similar patch
> > to do the same on arm.
> 
> This looks good to me, Rob, does that approach work for you?

Any news about that?

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net

Re: [PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Moessbauer Felix]

On Wed, 2022-05-18 at 12:52 -0700, Florian Fainelli wrote:
> 
> 
> On 4/27/2022 4:36 PM, Aurelien Jarno wrote:
> > This patchset changes the generation of the Raspberry Pi devices
> > DTB
> > files to improve the support for out-of-tree device-tree overlays,
> > like
> > it has recently been done for the Nvidia SoCs.
> > 
> > I personally only need that for arm64, but I have added a similar
> > patch
> > to do the same on arm.
> 
> This looks good to me, Rob, does that approach work for you?

Since May 2023 this patch is integrated into the Debian kernel build
[1]. However it would be better if we could integrate it into the
kernel directly. Is there anything blocking? For me, the patch looks
fine. Similar patches for Nvidia boards also already got integrated
[2].

If there is no general objection against enabling the overlays, I plan
to send patches for the sun8i-h3 arm boards as well.

Best regards,
Felix Moessbauer
Siemens AG

[1]
https://salsa.debian.org/kernel-team/linux/-/commit/fae42149fd0a37c68a496efbbb11f1dac484a163
[2]
https://lore.kernel.org/all/20220203184327.65878-1-jonathanh@nvidia.com/T/

Re: [PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Stefan Wahren]

Hi Felix,

Am 27.06.23 um 03:56 schrieb Moessbauer Felix:
> On Wed, 2022-05-18 at 12:52 -0700, Florian Fainelli wrote:
>>
>>
>> On 4/27/2022 4:36 PM, Aurelien Jarno wrote:
>>> This patchset changes the generation of the Raspberry Pi devices
>>> DTB
>>> files to improve the support for out-of-tree device-tree overlays,
>>> like
>>> it has recently been done for the Nvidia SoCs.
>>>
>>> I personally only need that for arm64, but I have added a similar
>>> patch
>>> to do the same on arm.
>>
>> This looks good to me, Rob, does that approach work for you?
> 
> Since May 2023 this patch is integrated into the Debian kernel build
> [1]. However it would be better if we could integrate it into the
> kernel directly. Is there anything blocking? For me, the patch looks
> fine. Similar patches for Nvidia boards also already got integrated
> [2].
> 
> If there is no general objection against enabling the overlays, I plan
> to send patches for the sun8i-h3 arm boards as well.

this series has been resubmitted recently and applied. Could you please 
check current linux-next?

Best regards

> 
> Best regards,
> Felix Moessbauer
> Siemens AG
> 
> [1]
> https://salsa.debian.org/kernel-team/linux/-/commit/fae42149fd0a37c68a496efbbb11f1dac484a163
> [2]
> https://lore.kernel.org/all/20220203184327.65878-1-jonathanh@nvidia.com/T/

Re: [PATCH RESEND 0/2] arm/arm64: dts: Enable device-tree overlay support for RPi devices

[Moessbauer Felix]

On Tue, 2023-06-27 at 07:59 +0200, Stefan Wahren wrote:
> Hi Felix,
> 
> Am 27.06.23 um 03:56 schrieb Moessbauer Felix:
> > On Wed, 2022-05-18 at 12:52 -0700, Florian Fainelli wrote:
> > > 
> > > 
> > > On 4/27/2022 4:36 PM, Aurelien Jarno wrote:
> > > > This patchset changes the generation of the Raspberry Pi
> > > > devices
> > > > DTB
> > > > files to improve the support for out-of-tree device-tree
> > > > overlays,
> > > > like
> > > > it has recently been done for the Nvidia SoCs.
> > > > 
> > > > I personally only need that for arm64, but I have added a
> > > > similar
> > > > patch
> > > > to do the same on arm.
> > > 
> > > This looks good to me, Rob, does that approach work for you?
> > 
> > Since May 2023 this patch is integrated into the Debian kernel
> > build
> > [1]. However it would be better if we could integrate it into the
> > kernel directly. Is there anything blocking? For me, the patch
> > looks
> > fine. Similar patches for Nvidia boards also already got integrated
> > [2].
> > 
> > If there is no general objection against enabling the overlays, I
> > plan
> > to send patches for the sun8i-h3 arm boards as well.
> 
> this series has been resubmitted recently and applied. Could you
> please 
> check current linux-next?

Thanks for the quick response. That was indeed a very recent change
(not yet in a release) which I missed.

Then I'll send the patches for the sun8i-h3-*pi*.dts by end of today.

Felix

> 
> Best regards
> 
> > 
> > Best regards,
> > Felix Moessbauer
> > Siemens AG
> > 
> > [1]
> > https://salsa.debian.org/kernel-team/linux/-/commit/fae42149fd0a37c68a496efbbb11f1dac484a163
> > [2]
> > https://lore.kernel.org/all/20220203184327.65878-1-jonathanh@nvidia.com/T/