[PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Uwe Kleine-König]

Hello,

based on an earlier submission by Aurelien Jarno, I rebased and slightly
simplified the patches.

There was some related irc conversion in #armlinux. Quoting the relevant
parts:

1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
1685078920< ukleinek> arnd, [florian]: If there is an agreement in general that this is a good idea, I can coordinate with Aurelien that for arm64 there is a v2 with the simpler approach I pointed out.
1685083481< arnd> ukleinek: I have no objections to this, if [florian] wants to pick it up and send me for 6.5.
1685083809< arnd> robher: any comments on this one?
1685466520 < [florian]> ukleinek: I was hoping we would get an Ack for robher before picking it up in the brcm soc tree, don't want to ruffle any feathers unnecessarily

So it seems to start a beneficial chain reaction, only Rob's Ack is
needed.

As these two changes would greatly simplify the application of dtbos for
rpi hats, I look forward to Rob agreeing to them.

Best regards
Uwe

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 |  4 ++++
 2 files changed, 22 insertions(+)

base-commit: ac9a78681b921877518763ba0e89202254349d1b
-- 
2.39.2

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

[Uwe Kleine-König]

From: Aurelien Jarno <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 v6.4-rc1 increase in size is as follows:

  bcm2711-rpi-400.dtb       27556 -> 38141 bytes
  bcm2711-rpi-4-b.dtb       27484 -> 38069 bytes
  bcm2711-rpi-cm4-io.dtb    27373 -> 38076 bytes
  bcm2837-rpi-3-a-plus.dtb  14930 -> 20713 bytes
  bcm2837-rpi-3-b.dtb       15107 -> 20979 bytes
  bcm2837-rpi-3-b-plus.dtb  15463 -> 21443 bytes
  bcm2837-rpi-cm3-io3.dtb   14429 -> 20098 bytes
  bcm2837-rpi-zero-2-w.dtb  14781 -> 20524 bytes

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/r/20220410225940.135744-2-aurelien@aurel32.net
[ukleinek: rebased to v6.4, replaced by a single assignment to DTC_FLAGS]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 arch/arm64/boot/dts/broadcom/Makefile | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/broadcom/Makefile b/arch/arm64/boot/dts/broadcom/Makefile
index 05d8c5ecf3b0..8b4591ddd27c 100644
--- a/arch/arm64/boot/dts/broadcom/Makefile
+++ b/arch/arm64/boot/dts/broadcom/Makefile
@@ -1,4 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
+
+# Enables support for device-tree overlays
+DTC_FLAGS := -@
+
 dtb-$(CONFIG_ARCH_BCM2835) += bcm2711-rpi-400.dtb \
 			      bcm2711-rpi-4-b.dtb \
 			      bcm2711-rpi-cm4-io.dtb \
-- 
2.39.2

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

[Uwe Kleine-König]

From: Aurelien Jarno <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 v6.4-rc1 increase in size is as follows:

  bcm2711-rpi-400.dtb       27556 -> 38141 bytes
  bcm2711-rpi-4-b.dtb       27484 -> 38069 bytes
  bcm2711-rpi-cm4-io.dtb    27373 -> 38076 bytes
  bcm2835-rpi-a.dtb         12879 -> 18235 bytes
  bcm2835-rpi-a-plus.dtb    13015 -> 18371 bytes
  bcm2835-rpi-b.dtb         12997 -> 18377 bytes
  bcm2835-rpi-b-plus.dtb    13237 -> 18666 bytes
  bcm2835-rpi-b-rev2.dtb    13085 -> 18514 bytes
  bcm2835-rpi-cm1-io1.dtb   13109 -> 18528 bytes
  bcm2835-rpi-zero.dtb      12923 -> 18311 bytes
  bcm2835-rpi-zero-w.dtb    13449 -> 18889 bytes
  bcm2836-rpi-2-b.dtb       14500 -> 20252 bytes
  bcm2837-rpi-3-a-plus.dtb  14930 -> 20713 bytes
  bcm2837-rpi-3-b.dtb       15107 -> 20979 bytes
  bcm2837-rpi-3-b-plus.dtb  15463 -> 21443 bytes
  bcm2837-rpi-cm3-io3.dtb   14429 -> 20098 bytes
  bcm2837-rpi-zero-2-w.dtb  14781 -> 20524 bytes

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/r/20220410225940.135744-3-aurelien@aurel32.net
[ukleinek: rebased to v6.4-rc1]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 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 59829fc90315..68e89f9289ef 100644
--- a/arch/arm/boot/dts/Makefile
+++ b/arch/arm/boot/dts/Makefile
@@ -85,6 +85,24 @@ dtb-$(CONFIG_SOC_SP7021) += \
 	sunplus-sp7021-demo-v3.dtb
 dtb-$(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 \
-- 
2.39.2

Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Uwe Kleine-König]

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Hello,

On Tue, May 30, 2023 at 07:56:22PM +0200, Uwe Kleine-König wrote:
> based on an earlier submission by Aurelien Jarno, I rebased and slightly
> simplified the patches.
> 
> There was some related irc conversion in #armlinux. Quoting the relevant
> parts:
> 
> 1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
> 1685078920< ukleinek> arnd, [florian]: If there is an agreement in general that this is a good idea, I can coordinate with Aurelien that for arm64 there is a v2 with the simpler approach I pointed out.
> 1685083481< arnd> ukleinek: I have no objections to this, if [florian] wants to pick it up and send me for 6.5.
> 1685083809< arnd> robher: any comments on this one?
> 1685466520 < [florian]> ukleinek: I was hoping we would get an Ack for robher before picking it up in the brcm soc tree, don't want to ruffle any feathers unnecessarily
> 
> So it seems to start a beneficial chain reaction, only Rob's Ack is
> needed.

Not sure this might help, but as Rob seems to be away for mail, I'll
try: arch/arm64/boot/dts/nvidia/Makefile and
arch/arm64/boot/dts/ti/Makefile also make use of -@. So this patch at
least isn't a completely new thing and maybe Florian might dare to take
this patch even without Rob's explicit consent?!

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Conor Dooley]

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On Thu, Jun 01, 2023 at 04:02:14PM +0200, Uwe Kleine-König wrote:
> Hello,
> 
> On Tue, May 30, 2023 at 07:56:22PM +0200, Uwe Kleine-König wrote:
> > based on an earlier submission by Aurelien Jarno, I rebased and slightly
> > simplified the patches.
> > 
> > There was some related irc conversion in #armlinux. Quoting the relevant
> > parts:
> > 
> > 1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
> > 1685078920< ukleinek> arnd, [florian]: If there is an agreement in general that this is a good idea, I can coordinate with Aurelien that for arm64 there is a v2 with the simpler approach I pointed out.
> > 1685083481< arnd> ukleinek: I have no objections to this, if [florian] wants to pick it up and send me for 6.5.
> > 1685083809< arnd> robher: any comments on this one?
> > 1685466520 < [florian]> ukleinek: I was hoping we would get an Ack for robher before picking it up in the brcm soc tree, don't want to ruffle any feathers unnecessarily
> > 
> > So it seems to start a beneficial chain reaction, only Rob's Ack is
> > needed.
> 
> Not sure this might help, but as Rob seems to be away for mail, I'll
> try: arch/arm64/boot/dts/nvidia/Makefile and
> arch/arm64/boot/dts/ti/Makefile also make use of -@. So this patch at
> least isn't a completely new thing and maybe Florian might dare to take
> this patch even without Rob's explicit consent?!

FWIW you can have mine, unless it is explicitly Rob's you want Florian.
Acked-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

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Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Florian Fainelli]

On 6/1/2023 7:13 AM, Conor Dooley wrote:
> On Thu, Jun 01, 2023 at 04:02:14PM +0200, Uwe Kleine-König wrote:
>> Hello,
>>
>> On Tue, May 30, 2023 at 07:56:22PM +0200, Uwe Kleine-König wrote:
>>> based on an earlier submission by Aurelien Jarno, I rebased and slightly
>>> simplified the patches.
>>>
>>> There was some related irc conversion in #armlinux. Quoting the relevant
>>> parts:
>>>
>>> 1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
>>> 1685078920< ukleinek> arnd, [florian]: If there is an agreement in general that this is a good idea, I can coordinate with Aurelien that for arm64 there is a v2 with the simpler approach I pointed out.
>>> 1685083481< arnd> ukleinek: I have no objections to this, if [florian] wants to pick it up and send me for 6.5.
>>> 1685083809< arnd> robher: any comments on this one?
>>> 1685466520 < [florian]> ukleinek: I was hoping we would get an Ack for robher before picking it up in the brcm soc tree, don't want to ruffle any feathers unnecessarily
>>>
>>> So it seems to start a beneficial chain reaction, only Rob's Ack is
>>> needed.
>>
>> Not sure this might help, but as Rob seems to be away for mail, I'll
>> try: arch/arm64/boot/dts/nvidia/Makefile and
>> arch/arm64/boot/dts/ti/Makefile also make use of -@. So this patch at
>> least isn't a completely new thing and maybe Florian might dare to take
>> this patch even without Rob's explicit consent?!
> 
> FWIW you can have mine, unless it is explicitly Rob's you want Florian.
> Acked-by: Conor Dooley <conor.dooley@microchip.com>

OK, I will take yours and queue those up!
-- 
Florian

Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Florian Fainelli]

On 6/1/23 08:37, Florian Fainelli wrote:
> 
> 
> On 6/1/2023 7:13 AM, Conor Dooley wrote:
>> On Thu, Jun 01, 2023 at 04:02:14PM +0200, Uwe Kleine-König wrote:
>>> Hello,
>>>
>>> On Tue, May 30, 2023 at 07:56:22PM +0200, Uwe Kleine-König wrote:
>>>> based on an earlier submission by Aurelien Jarno, I rebased and 
>>>> slightly
>>>> simplified the patches.
>>>>
>>>> There was some related irc conversion in #armlinux. Quoting the 
>>>> relevant
>>>> parts:
>>>>
>>>> 1685078851< ukleinek> arnd, [florian]: Who would pick up 
>>>> https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
>>>> 1685078920< ukleinek> arnd, [florian]: If there is an agreement in 
>>>> general that this is a good idea, I can coordinate with Aurelien 
>>>> that for arm64 there is a v2 with the simpler approach I pointed out.
>>>> 1685083481< arnd> ukleinek: I have no objections to this, if 
>>>> [florian] wants to pick it up and send me for 6.5.
>>>> 1685083809< arnd> robher: any comments on this one?
>>>> 1685466520 < [florian]> ukleinek: I was hoping we would get an Ack 
>>>> for robher before picking it up in the brcm soc tree, don't want to 
>>>> ruffle any feathers unnecessarily
>>>>
>>>> So it seems to start a beneficial chain reaction, only Rob's Ack is
>>>> needed.
>>>
>>> Not sure this might help, but as Rob seems to be away for mail, I'll
>>> try: arch/arm64/boot/dts/nvidia/Makefile and
>>> arch/arm64/boot/dts/ti/Makefile also make use of -@. So this patch at
>>> least isn't a completely new thing and maybe Florian might dare to take
>>> this patch even without Rob's explicit consent?!
>>
>> FWIW you can have mine, unless it is explicitly Rob's you want Florian.
>> Acked-by: Conor Dooley <conor.dooley@microchip.com>
> 
> OK, I will take yours and queue those up!

Applied both with Conor's ack. Uwe, please copy 
bcm-kernel-feedback-list@broadcom.com next time, so the patches show up 
in our patchwork and make my life a tad easier ;)

Thanks everyone.
-- 
Florian

Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Uwe Kleine-König]

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Hello Florian,

On Thu, Jun 01, 2023 at 10:40:07AM -0700, Florian Fainelli wrote:
> On 6/1/23 08:37, Florian Fainelli wrote:
> > On 6/1/2023 7:13 AM, Conor Dooley wrote:
> > > On Thu, Jun 01, 2023 at 04:02:14PM +0200, Uwe Kleine-König wrote:
> > > > On Tue, May 30, 2023 at 07:56:22PM +0200, Uwe Kleine-König wrote:
> > > > > based on an earlier submission by Aurelien Jarno, I rebased
> > > > > and slightly
> > > > > simplified the patches.
> > > > > 
> > > > > There was some related irc conversion in #armlinux. Quoting
> > > > > the relevant
> > > > > parts:
> > > > > 
> > > > > 1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net
> > > > > ?
> > > > > 1685078920< ukleinek> arnd, [florian]: If there is an
> > > > > agreement in general that this is a good idea, I can
> > > > > coordinate with Aurelien that for arm64 there is a v2 with
> > > > > the simpler approach I pointed out.
> > > > > 1685083481< arnd> ukleinek: I have no objections to this, if
> > > > > [florian] wants to pick it up and send me for 6.5.
> > > > > 1685083809< arnd> robher: any comments on this one?
> > > > > 1685466520 < [florian]> ukleinek: I was hoping we would get
> > > > > an Ack for robher before picking it up in the brcm soc tree,
> > > > > don't want to ruffle any feathers unnecessarily
> > > > > 
> > > > > So it seems to start a beneficial chain reaction, only Rob's Ack is
> > > > > needed.
> > > > 
> > > > Not sure this might help, but as Rob seems to be away for mail, I'll
> > > > try: arch/arm64/boot/dts/nvidia/Makefile and
> > > > arch/arm64/boot/dts/ti/Makefile also make use of -@. So this patch at
> > > > least isn't a completely new thing and maybe Florian might dare to take
> > > > this patch even without Rob's explicit consent?!
> > > 
> > > FWIW you can have mine, unless it is explicitly Rob's you want Florian.
> > > Acked-by: Conor Dooley <conor.dooley@microchip.com>
> > 
> > OK, I will take yours and queue those up!
> 
> Applied both with Conor's ack.

Thanks to all people involved here. I'm really glad this is accepted
now, it will make using dtbos in Debian quite a bit simpler.

> Uwe, please copy
> bcm-kernel-feedback-list@broadcom.com next time, so the patches show up in
> our patchwork and make my life a tad easier ;)

You could be relatively sure I will do that, if the MAINTAINERS file
gets modified such that

	scripts/get_maintainer.pl -f arch/arm64/boot/dts/broadcom/Makefile

includes this address. I took a quick look, but it wasn't obvious to me
which entry should be expanded accordingly. (But I'll try to remember
anyhow.)

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH 0/2] arm*/dts: Enable symbols for rpi device trees

[Cristian.Birsan]

Hi Uwe, All,

On 5/30/23 20:56, Uwe Kleine-König wrote:
> Hello,
> 
> based on an earlier submission by Aurelien Jarno, I rebased and slightly
> simplified the patches.
> 
> There was some related irc conversion in #armlinux. Quoting the relevant
> parts:
> 
> 1685078851< ukleinek> arnd, [florian]: Who would pick up https://lore.kernel.org/linux-arm-kernel/20220410225940.135744-1-aurelien@aurel32.net ?
> 1685078920< ukleinek> arnd, [florian]: If there is an agreement in general that this is a good idea, I can coordinate with Aurelien that for arm64 there is a v2 with the simpler approach I pointed out.
> 1685083481< arnd> ukleinek: I have no objections to this, if [florian] wants to pick it up and send me for 6.5.
> 1685083809< arnd> robher: any comments on this one?
> 1685466520 < [florian]> ukleinek: I was hoping we would get an Ack for robher before picking it up in the brcm soc tree, don't want to ruffle any feathers unnecessarily
> 
> So it seems to start a beneficial chain reaction, only Rob's Ack is
> needed.
> 
> As these two changes would greatly simplify the application of dtbos for
> rpi hats, I look forward to Rob agreeing to them.

I'm interested in enabling this feature too. We used device tree overlays for Microchip AT91 boards for some time.

I can prepare a similar patch to enable them upstream.

> 
> Best regards
> Uwe

Regards,
Cristi


> 
> 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 |  4 ++++
>   2 files changed, 22 insertions(+)
> 
> base-commit: ac9a78681b921877518763ba0e89202254349d1b