[PATCH 0/5] Add support for Seeed Studio BeagleBone HDMI cape overlay

[PATCH 0/5] Add support for Seeed Studio BeagleBone HDMI cape overlay

[Kory Maincent (TI)]

Add devicetree overlay for the Seeed Studio BeagleBone HDMI cape, which
provides HDMI output via an ITE IT66121 HDMI bridge and audio support
through McASP.

https://www.seeedstudio.com/Seeed-Studio-BeagleBoner-Green-HDMI-Cape.html

This overlay requires the recent tilcdc cleanup patch series that was merged
to drm-misc-next to function properly:
https://lore.kernel.org/lkml/20260123-feature_tilcdc-v5-0-5a44d2aa3f6f@bootlin.com/

With this DRM tree dependency I don't know if this series should land in
DRM tree or in OMAP tree.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
Kory Maincent (TI) (5):
      ARM: dts: ti: Enable overlays for all DTB files
      ARM: multi_v7_defconfig: Enable TILCDC DRM driver
      ARM: omap2plus_defconfig: Enable ITE IT66121 driver
      ARM: multi_v7_defconfig: Enable ITE IT66121 driver
      ARM: dts: am335x: Add Seeed Studio BeagleBone HDMI cape overlay

 arch/arm/boot/dts/ti/omap/Makefile                 |   8 ++
 .../boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso    | 157 +++++++++++++++++++++
 arch/arm/configs/multi_v7_defconfig                |   2 +
 arch/arm/configs/omap2plus_defconfig               |   1 +
 4 files changed, 168 insertions(+)
---
base-commit: 40c1ccc1a3b86259e455a9a5082d5c8e0f944d62
change-id: 20260212-feature_bbge-932870b2edf5

Best regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

[PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Kory Maincent (TI)]

Allow overlays to be applied to any DTB. This adds around ~40% to the
total size of the DTB files on average.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
--

Enable overlays for all dtb similarly to what has been done for arch64
TI boards, but we could only enable overlays for Beagle Bone and
variant boards if required.
---
 arch/arm/boot/dts/ti/omap/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/dts/ti/omap/Makefile b/arch/arm/boot/dts/ti/omap/Makefile
index 14e500846875e..52df04328aff2 100644
--- a/arch/arm/boot/dts/ti/omap/Makefile
+++ b/arch/arm/boot/dts/ti/omap/Makefile
@@ -175,3 +175,6 @@ dtb-$(CONFIG_SOC_TI81XX) += \
 	dm8148-t410.dtb \
 	dm8168-evm.dtb \
 	dra62x-j5eco-evm.dtb
+
+# Enable support for device-tree overlays
+DTC_FLAGS := -@

-- 
2.43.0

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Krzysztof Kozlowski]

On 12/02/2026 16:26, Kory Maincent (TI) wrote:
> Allow overlays to be applied to any DTB. This adds around ~40% to the
> total size of the DTB files on average.
> 
> Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
> --
> 
> Enable overlays for all dtb similarly to what has been done for arch64
> TI boards, but we could only enable overlays for Beagle Bone and
> variant boards if required.

You mixed changelog with commit with invalid separator thus there is no
final SoB.


Best regards,
Krzysztof

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Kory Maincent]

On Thu, 12 Feb 2026 16:42:12 +0100
Krzysztof Kozlowski <krzk@kernel.org> wrote:

> On 12/02/2026 16:26, Kory Maincent (TI) wrote:
> > Allow overlays to be applied to any DTB. This adds around ~40% to the
> > total size of the DTB files on average.
> > 
> > Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
> > --
> > 
> > Enable overlays for all dtb similarly to what has been done for arch64
> > TI boards, but we could only enable overlays for Beagle Bone and
> > variant boards if required.  
> 
> You mixed changelog with commit with invalid separator thus there is no
> final SoB.

Arf forgot one '-'. Sorry for that.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[H. Nikolaus Schaller]

> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
> 
> Allow overlays to be applied to any DTB. This adds around ~40% to the
> total size of the DTB files on average.

Is this unconditionally enabled or can it be turned off by some CONFIG? We have
our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
and disabled in ours.

We have several devices where the boot loader can't handle overlays (never touch
a working boot-loader :) So this seems to only contribute to build and load time
without benefit.

BR,
Nikolaus

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Andreas Kemnade]

On Thu, 12 Feb 2026 16:49:43 +0100
"H. Nikolaus Schaller" <hns@goldelico.com> wrote:

> > Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
> > 
> > Allow overlays to be applied to any DTB. This adds around ~40% to the
> > total size of the DTB files on average.  
> 
> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
> and disabled in ours.
> 
> We have several devices where the boot loader can't handle overlays (never touch
> a working boot-loader :) So this seems to only contribute to build and load time
> without benefit.
> 
As long as you do not add overlays, the bootloader does not care. I would
like to simply carry around the 1-bit mmc overlay for one broken board.
That would help me. So I think there is a benefit but nobody forces
you to use it.

Regards,
Andreas

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[H. Nikolaus Schaller]

> Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
> 
> On Thu, 12 Feb 2026 16:49:43 +0100
> "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> 
>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
>>> 
>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
>>> total size of the DTB files on average.  
>> 
>> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
>> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
>> and disabled in ours.
>> 
>> We have several devices where the boot loader can't handle overlays (never touch
>> a working boot-loader :) So this seems to only contribute to build and load time
>> without benefit.
>> 
> As long as you do not add overlays, the bootloader does not care. I would
> like to simply carry around the 1-bit mmc overlay for one broken board.
> That would help me. So I think there is a benefit but nobody forces
> you to use it.

Well, it does not force to use the really good feature, but it forces to add
~40% more file size and some more compile time, if I understand it correctly.

This makes me think that it should be an option to turn it off completely (and
not just ignore it by the boot loader).

BR,
Nikolaus

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Andreas Kemnade]

On Thu, 12 Feb 2026 17:55:43 +0100
"H. Nikolaus Schaller" <hns@goldelico.com> wrote:

> > Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
> > 
> > On Thu, 12 Feb 2026 16:49:43 +0100
> > "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> >   
> >>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
> >>> 
> >>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> >>> total size of the DTB files on average.    
> >> 
> >> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
> >> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
> >> and disabled in ours.
> >> 
> >> We have several devices where the boot loader can't handle overlays (never touch
> >> a working boot-loader :) So this seems to only contribute to build and load time
> >> without benefit.
> >>   
> > As long as you do not add overlays, the bootloader does not care. I would
> > like to simply carry around the 1-bit mmc overlay for one broken board.
> > That would help me. So I think there is a benefit but nobody forces
> > you to use it.  
> 
> Well, it does not force to use the really good feature, but it forces to add
> ~40% more file size and some more compile time, if I understand it correctly.
> 
Compile time, hardly measurable even if you just do make dtbs.

Size on disk:
a) if it lives around in a /boot partitions with kernels and initrams in it,
   then we are around 1% more space needed.

b) if it has separate partitions maybe on some mtd: Looking around: GTA04
   has quite some headroom left. Usage is still <50% even with symbols
   enabled.

But on the other no one else seems to enable that besides for devices with
open expansion boards carrying "hats". So overall, should we really be the
exception? 

Regards,
Andreas

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Robert Nelson]

On Thu, Feb 12, 2026 at 4:19 PM Andreas Kemnade <andreas@kemnade.info> wrote:
>
> On Thu, 12 Feb 2026 17:55:43 +0100
> "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>
> > > Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
> > >
> > > On Thu, 12 Feb 2026 16:49:43 +0100
> > > "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> > >
> > >>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
> > >>>
> > >>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> > >>> total size of the DTB files on average.
> > >>
> > >> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
> > >> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
> > >> and disabled in ours.
> > >>
> > >> We have several devices where the boot loader can't handle overlays (never touch
> > >> a working boot-loader :) So this seems to only contribute to build and load time
> > >> without benefit.
> > >>
> > > As long as you do not add overlays, the bootloader does not care. I would
> > > like to simply carry around the 1-bit mmc overlay for one broken board.
> > > That would help me. So I think there is a benefit but nobody forces
> > > you to use it.
> >
> > Well, it does not force to use the really good feature, but it forces to add
> > ~40% more file size and some more compile time, if I understand it correctly.
> >
> Compile time, hardly measurable even if you just do make dtbs.
>
> Size on disk:
> a) if it lives around in a /boot partitions with kernels and initrams in it,
>    then we are around 1% more space needed.
>
> b) if it has separate partitions maybe on some mtd: Looking around: GTA04
>    has quite some headroom left. Usage is still <50% even with symbols
>    enabled.
>
> But on the other no one else seems to enable that besides for devices with
> open expansion boards carrying "hats". So overall, should we really be the
> exception?

Do we want to maybe transition like TI did for k3?

Start with board specific DTC_FLAGS flags for specific boards:

and then just enabling overlays by default :
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64/boot/dts/ti/Makefile?id=bca4146b1f66dbca07591bfd6ad695c699b5a093

If we do board-specific, all the "Beagle" related items can be auto
enabled `-@`..

Regards,

-- 
Robert Nelson
https://rcn-ee.com/

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Kory Maincent]

On Thu, 12 Feb 2026 21:16:05 -0600
Robert Nelson <robertcnelson@gmail.com> wrote:

> On Thu, Feb 12, 2026 at 4:19 PM Andreas Kemnade <andreas@kemnade.info> wrote:
> >
> > On Thu, 12 Feb 2026 17:55:43 +0100
> > "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> >  
> > > > Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
> > > >
> > > > On Thu, 12 Feb 2026 16:49:43 +0100
> > > > "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> > > >  
> > > >>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI)
> > > >>> <kory.maincent@bootlin.com>:
> > > >>>
> > > >>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> > > >>> total size of the DTB files on average.  
> > > >>
> > > >> Is this unconditionally enabled or can it be turned off by some
> > > >> CONFIG? We have our own defconfig so I would not worry if if is
> > > >> enabled in omap2plus_defconfig and disabled in ours.
> > > >>
> > > >> We have several devices where the boot loader can't handle overlays
> > > >> (never touch a working boot-loader :) So this seems to only contribute
> > > >> to build and load time without benefit.
> > > >>  
> > > > As long as you do not add overlays, the bootloader does not care. I
> > > > would like to simply carry around the 1-bit mmc overlay for one broken
> > > > board. That would help me. So I think there is a benefit but nobody
> > > > forces you to use it.  
> > >
> > > Well, it does not force to use the really good feature, but it forces to
> > > add ~40% more file size and some more compile time, if I understand it
> > > correctly. 
> > Compile time, hardly measurable even if you just do make dtbs.
> >
> > Size on disk:
> > a) if it lives around in a /boot partitions with kernels and initrams in it,
> >    then we are around 1% more space needed.
> >
> > b) if it has separate partitions maybe on some mtd: Looking around: GTA04
> >    has quite some headroom left. Usage is still <50% even with symbols
> >    enabled.
> >
> > But on the other no one else seems to enable that besides for devices with
> > open expansion boards carrying "hats". So overall, should we really be the
> > exception?  
> 
> Do we want to maybe transition like TI did for k3?
> 
> Start with board specific DTC_FLAGS flags for specific boards:
> 
> and then just enabling overlays by default :
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64/boot/dts/ti/Makefile?id=bca4146b1f66dbca07591bfd6ad695c699b5a093
> 
> If we do board-specific, all the "Beagle" related items can be auto
> enabled `-@`..

Yes, I will move on to this solution for now to avoid too many complaints about
the devicetree size increases.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[H. Nikolaus Schaller]

Hi Kory,

> Am 16.02.2026 um 16:11 schrieb Kory Maincent <kory.maincent@bootlin.com>:
> 
>>>>> 
>>>>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI)
>>>>>>> <kory.maincent@bootlin.com>:
>>>>>>> 
>>>>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
>>>>>>> total size of the DTB files on average.  
> 
> Yes, I will move on to this solution for now to avoid too many complaints about
> the devicetree size increases.

I have done some experimentation with this patch (on top of v6.19 and our private defconfig)
but could not find any DTB size increase.

Does it require another patch or CONFIG change?

BR,
Nikolaus

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Andreas Kemnade]

On Tue, 17 Feb 2026 09:58:04 +0100
H. Nikolaus Schaller <hns@goldelico.com> wrote:

> Hi Kory,
> 
> > Am 16.02.2026 um 16:11 schrieb Kory Maincent <kory.maincent@bootlin.com>:
> >   
> >>>>>   
> >>>>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI)
> >>>>>>> <kory.maincent@bootlin.com>:
> >>>>>>> 
> >>>>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> >>>>>>> total size of the DTB files on average.    
> > 
> > Yes, I will move on to this solution for now to avoid too many complaints about
> > the devicetree size increases.  
> 
> I have done some experimentation with this patch (on top of v6.19 and our private defconfig)
> but could not find any DTB size increase.
> 
> Does it require another patch or CONFIG change?
> 
if it is your letux_defconfig, then it does not require anything else.

I think something already enables symbols in your tree. Look with
fdtdump at the generated dtbs for a __symbols__ node.
If it is there, then it is enabled.

Regards,
Andreas

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Kory Maincent]

On Tue, 17 Feb 2026 09:58:04 +0100
H. Nikolaus Schaller <hns@goldelico.com> wrote:

> Hi Kory,
> 
> > Am 16.02.2026 um 16:11 schrieb Kory Maincent <kory.maincent@bootlin.com>:
> >   
> >>>>>   
> >>>>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI)
> >>>>>>> <kory.maincent@bootlin.com>:
> >>>>>>> 
> >>>>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> >>>>>>> total size of the DTB files on average.    
> > 
> > Yes, I will move on to this solution for now to avoid too many complaints
> > about the devicetree size increases.  
> 
> I have done some experimentation with this patch (on top of v6.19 and our
> private defconfig) but could not find any DTB size increase.
> 
> Does it require another patch or CONFIG change?

No, but maybe you had already the "DTC_FLAGS=-@" option enabled while building
you image.
This options add the "__symbols__" node listing the symbols to the built
devicetree:
$ fdtdump arch/arm/boot/dts/ti/omap/am335x-bonegreen-eco.dtb 2>/dev/null | grep symbols

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[H. Nikolaus Schaller]

Hi Kory,

> Am 17.02.2026 um 10:36 schrieb Kory Maincent <kory.maincent@bootlin.com>:
> 
> On Tue, 17 Feb 2026 09:58:04 +0100
> H. Nikolaus Schaller <hns@goldelico.com> wrote:
> 
>> Hi Kory,
>> 
>>> Am 16.02.2026 um 16:11 schrieb Kory Maincent <kory.maincent@bootlin.com>:
>>> 
>>>>>>> 
>>>>>>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI)
>>>>>>>>> <kory.maincent@bootlin.com>:
>>>>>>>>> 
>>>>>>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
>>>>>>>>> total size of the DTB files on average.    
>>> 
>>> Yes, I will move on to this solution for now to avoid too many complaints
>>> about the devicetree size increases.  
>> 
>> I have done some experimentation with this patch (on top of v6.19 and our
>> private defconfig) but could not find any DTB size increase.
>> 
>> Does it require another patch or CONFIG change?
> 
> No, but maybe you had already the "DTC_FLAGS=-@" option enabled while building
> you image.
> This options add the "__symbols__" node listing the symbols to the built
> devicetree:
> $ fdtdump arch/arm/boot/dts/ti/omap/am335x-bonegreen-eco.dtb 2>/dev/null | grep symbols

Yes, indeed there is a __symbols__ node in all .dtb I have checked.

With make V=1 (on v6.19.0 + some local extensions) I see

./scripts/dtc/dtc -o arch/arm/boot/dts/ti/omap/am335x-bonegreen.dtb -b 0 -iarch/arm/boot/dts/ti/omap/ -i./scripts/dtc/include-prefixes -Wno-interrupt_provider --symbol -Wno-unique_unit_address -Wno-unit_address_vs_reg -Wno-avoid_unnecessary_addr_size -Wno-alias_paths -Wno-graph_child_address -Wno-simple_bus_reg   -Wno-unique_unit_address -Wno-unit_address_vs_reg -Wno-avoid_unnecessary_addr_size -Wno-alias_paths -Wno-graph_child_address -Wno-interrupt_map -Wno-simple_bus_reg   -d arch/arm/boot/dts/ti/omap/.am335x-bonegreen.dtb.d.dtc.tmp arch/arm/boot/dts/ti/omap/.am335x-bonegreen.dtb.dts.tmp

So --symbol is already included, even without your patch.

With your patch I see:

./scripts/dtc/dtc -o arch/arm/boot/dts/ti/omap/am335x-bonegreen.dtb -b 0 -iarch/arm/boot/dts/ti/omap/ -i./scripts/dtc/include-prefixes -@ -Wno-interrupt_provider --symbol -Wno-unique_unit_address -Wno-unit_address_vs_reg -Wno-avoid_unnecessary_addr_size -Wno-alias_paths -Wno-graph_child_address -Wno-simple_bus_reg   -Wno-unique_unit_address -Wno-unit_address_vs_reg -Wno-avoid_unnecessary_addr_size -Wno-alias_paths -Wno-graph_child_address -Wno-interrupt_map -Wno-simple_bus_reg   -d arch/arm/boot/dts/ti/omap/.am335x-bonegreen.dtb.d.dtc.tmp arch/arm/boot/dts/ti/omap/.am335x-bonegreen.dtb.dts.tmp

Here we have -@ and --symbol (synonyms for dtc).

Well, I finally could trace it down to a malicious infection of our LetuxOS tree
by some ODROID kernel patch to scripts/Makefile.lib (0ac84640f12c). That patch
globally modifies the DTC_FLAGS mechanism and permanently adds --symbol instead of adding
-@ in the arch/board specific Makefile like you propose here.

So now I know why I didn't see any increase in size (because it was never reduced).

With removing this I now get 67179 bytes as default for am335x-bonegreen.dtb.
And with your patch I get (back) to 94260 bytes so I can confirm a 40.3% increase.

Please proceed as planned (I don't think it necessarily has to be limited to
motherboards with an expansion card system, although that would be a good
indication of its usefulness), and thank you for bringing our local issue
to my attention.

BR and thanks,
Nikolaus

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[H. Nikolaus Schaller]

Hi,

> Am 12.02.2026 um 23:19 schrieb Andreas Kemnade <andreas@kemnade.info>:
> 
> On Thu, 12 Feb 2026 17:55:43 +0100
> "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> 
>>> Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
>>> 
>>> On Thu, 12 Feb 2026 16:49:43 +0100
>>> "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
>>> 
>>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
>>>>> 
>>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
>>>>> total size of the DTB files on average.    
>>>> 
>>>> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
>>>> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
>>>> and disabled in ours.
>>>> 
>>>> We have several devices where the boot loader can't handle overlays (never touch
>>>> a working boot-loader :) So this seems to only contribute to build and load time
>>>> without benefit.
>>>> 
>>> As long as you do not add overlays, the bootloader does not care. I would
>>> like to simply carry around the 1-bit mmc overlay for one broken board.
>>> That would help me. So I think there is a benefit but nobody forces
>>> you to use it.  
>> 
>> Well, it does not force to use the really good feature, but it forces to add
>> ~40% more file size and some more compile time, if I understand it correctly.
>> 
> Compile time, hardly measurable even if you just do make dtbs.
> 
> Size on disk:
> a) if it lives around in a /boot partitions with kernels and initrams in it,
>   then we are around 1% more space needed.

Ah, I see. I was too focussed on the "adds around ~40% to the total size of the DTB files".

For the Letux arm distro all DTBs are around 8.1 MB at the moment so it will grow not that much
(there are non-TI devices included).

So you are right, it is ~1% of the total if the kernel image is counted.

Therefore, space should not be something we should be too concerned about (although I remember
discussions for driver code where every single byte did count).

On the other hand this increases load time from (sometimes slow) µSD for a specific DTB by 40%.
That should at least be discussed.

BR,
Nikolaus

Re: [PATCH 1/5] ARM: dts: ti: Enable overlays for all DTB files

[Andreas Kemnade]

On Fri, 13 Feb 2026 06:33:46 +0100
"H. Nikolaus Schaller" <hns@goldelico.com> wrote:

> Hi,
> 
> > Am 12.02.2026 um 23:19 schrieb Andreas Kemnade <andreas@kemnade.info>:
> > 
> > On Thu, 12 Feb 2026 17:55:43 +0100
> > "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> >   
> >>> Am 12.02.2026 um 17:47 schrieb Andreas Kemnade <andreas@kemnade.info>:
> >>> 
> >>> On Thu, 12 Feb 2026 16:49:43 +0100
> >>> "H. Nikolaus Schaller" <hns@goldelico.com> wrote:
> >>>   
> >>>>> Am 12.02.2026 um 16:26 schrieb Kory Maincent (TI) <kory.maincent@bootlin.com>:
> >>>>> 
> >>>>> Allow overlays to be applied to any DTB. This adds around ~40% to the
> >>>>> total size of the DTB files on average.      
> >>>> 
> >>>> Is this unconditionally enabled or can it be turned off by some CONFIG? We have
> >>>> our own defconfig so I would not worry if if is enabled in omap2plus_defconfig
> >>>> and disabled in ours.
> >>>> 
> >>>> We have several devices where the boot loader can't handle overlays (never touch
> >>>> a working boot-loader :) So this seems to only contribute to build and load time
> >>>> without benefit.
> >>>>   
> >>> As long as you do not add overlays, the bootloader does not care. I would
> >>> like to simply carry around the 1-bit mmc overlay for one broken board.
> >>> That would help me. So I think there is a benefit but nobody forces
> >>> you to use it.    
> >> 
> >> Well, it does not force to use the really good feature, but it forces to add
> >> ~40% more file size and some more compile time, if I understand it correctly.
> >>   
> > Compile time, hardly measurable even if you just do make dtbs.
> > 
> > Size on disk:
> > a) if it lives around in a /boot partitions with kernels and initrams in it,
> >   then we are around 1% more space needed.  
> 
> Ah, I see. I was too focussed on the "adds around ~40% to the total size of the DTB files".
> 
> For the Letux arm distro all DTBs are around 8.1 MB at the moment so it will grow not that much
> (there are non-TI devices included).
> 
> So you are right, it is ~1% of the total if the kernel image is counted.
> 
> Therefore, space should not be something we should be too concerned about (although I remember
> discussions for driver code where every single byte did count).
> 
> On the other hand this increases load time from (sometimes slow) µSD for a specific DTB by 40%.
> That should at least be discussed.
> 
so also 1% of total loading time. And symbols can be stripped away during
e.g. deployment.
fdtput -r some_board.dtb /__symbols__

I am not strongly against it. It is just we are doing something unusual here.
Are there reasons why it is unusual I do not understand?
I think it can be useful for every board in some situations. For the
ones with can carry a head, they are the most useful.

What was the reasoning to have it enabled for k3 for every board? K3 and Broadcom-64bit
seem to be the only arch doing that. Broadcom mostly many RPis, some routers. 

Regards,
Andreas

[PATCH 2/5] ARM: multi_v7_defconfig: Enable TILCDC DRM driver

[Kory Maincent (TI)]

Enable CONFIG_DRM_TILCDC as a module to provide display support for
TI AM335x-based SoCs in the multi_v7 kernel configuration.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 7f1fa9dd88c92..196b6872ca463 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -735,6 +735,7 @@ CONFIG_DRM_RCAR_DU=m
 CONFIG_DRM_SUN4I=m
 CONFIG_DRM_OMAP=m
 CONFIG_OMAP5_DSS_HDMI=y
+CONFIG_DRM_TILCDC=m
 CONFIG_DRM_MSM=m
 CONFIG_DRM_FSL_DCU=m
 CONFIG_DRM_TEGRA=y

-- 
2.43.0

[PATCH 3/5] ARM: omap2plus_defconfig: Enable ITE IT66121 driver

[Kory Maincent (TI)]

Enable the ITE IT66121 HDMI bridge driver to support HDMI output on
the BeagleBone Green with the Seeed Studio HDMI cape.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
 arch/arm/configs/omap2plus_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
index 4e53c331cd841..cdf69ac2e5126 100644
--- a/arch/arm/configs/omap2plus_defconfig
+++ b/arch/arm/configs/omap2plus_defconfig
@@ -486,6 +486,7 @@ CONFIG_VIDEO_OMAP3=m
 CONFIG_VIDEO_MT9P031=m
 CONFIG_VIDEO_TVP5150=m
 CONFIG_DRM=m
+CONFIG_DRM_ITE_IT66121=m
 CONFIG_DRM_OMAP=m
 CONFIG_OMAP5_DSS_HDMI=y
 CONFIG_OMAP2_DSS_SDI=y

-- 
2.43.0

[PATCH 4/5] ARM: multi_v7_defconfig: Enable ITE IT66121 driver

[Kory Maincent (TI)]

Enable the ITE IT66121 HDMI bridge driver to support HDMI output on
the BeagleBone Green with the Seeed Studio HDMI cape.

Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 196b6872ca463..2c9587855f044 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -751,6 +751,7 @@ CONFIG_DRM_PANEL_SAMSUNG_S6E63J0X03=m
 CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0=m
 CONFIG_DRM_PANEL_SHARP_LQ101R1SX01=m
 CONFIG_DRM_DISPLAY_CONNECTOR=m
+CONFIG_DRM_ITE_IT66121=m
 CONFIG_DRM_LVDS_CODEC=m
 CONFIG_DRM_NXP_PTN3460=m
 CONFIG_DRM_PARADE_PS8622=m

-- 
2.43.0

Re: [PATCH 4/5] ARM: multi_v7_defconfig: Enable ITE IT66121 driver

[Krzysztof Kozlowski]

On 12/02/2026 16:26, Kory Maincent (TI) wrote:
> Enable the ITE IT66121 HDMI bridge driver to support HDMI output on
> the BeagleBone Green with the Seeed Studio HDMI cape.

This is not one option per patch. All three patches should be squashed,
because are logically one change.

Best regards,
Krzysztof

Re: [PATCH 4/5] ARM: multi_v7_defconfig: Enable ITE IT66121 driver

[Kory Maincent]

On Thu, 12 Feb 2026 16:40:14 +0100
Krzysztof Kozlowski <krzk@kernel.org> wrote:

> On 12/02/2026 16:26, Kory Maincent (TI) wrote:
> > Enable the ITE IT66121 HDMI bridge driver to support HDMI output on
> > the BeagleBone Green with the Seeed Studio HDMI cape.  
> 
> This is not one option per patch. All three patches should be squashed,
> because are logically one change.

Ok, as you prefer.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

[PATCH 5/5] ARM: dts: am335x: Add Seeed Studio BeagleBone HDMI cape overlay

[Kory Maincent (TI)]

Add devicetree overlay for the Seeed Studio BeagleBone HDMI cape, which
provides HDMI output via an ITE IT66121 HDMI bridge and audio support
through McASP.

The cape is designed for BeagleBone Green but is also compatible with
BeagleBone and BeagleBone Black due to pin compatibility.

Link: https://www.seeedstudio.com/Seeed-Studio-BeagleBoner-Green-HDMI-Cape.html
Signed-off-by: Kory Maincent (TI) <kory.maincent@bootlin.com>
---
 arch/arm/boot/dts/ti/omap/Makefile                 |   5 +
 .../boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso    | 157 +++++++++++++++++++++
 2 files changed, 162 insertions(+)

diff --git a/arch/arm/boot/dts/ti/omap/Makefile b/arch/arm/boot/dts/ti/omap/Makefile
index 52df04328aff2..23ae6df682206 100644
--- a/arch/arm/boot/dts/ti/omap/Makefile
+++ b/arch/arm/boot/dts/ti/omap/Makefile
@@ -82,6 +82,10 @@ dtb-$(CONFIG_ARCH_OMAP4) += \
 	omap4-var-stk-om44.dtb \
 	omap4-xyboard-mz609.dtb \
 	omap4-xyboard-mz617.dtb
+
+am335x-bonegreen-hdmi-00a0-dtbs := am335x-bonegreen-eco.dtb \
+	am335x-bone-hdmi-00a0.dtbo
+
 dtb-$(CONFIG_SOC_AM33XX) += \
 	am335x-baltos-ir2110.dtb \
 	am335x-baltos-ir3220.dtb \
@@ -94,6 +98,7 @@ dtb-$(CONFIG_SOC_AM33XX) += \
 	am335x-bonegreen.dtb \
 	am335x-bonegreen-wireless.dtb \
 	am335x-bonegreen-eco.dtb \
+	am335x-bonegreen-hdmi-00a0.dtb \
 	am335x-chiliboard.dtb \
 	am335x-cm-t335.dtb \
 	am335x-evm.dtb \
diff --git a/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso b/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso
new file mode 100644
index 0000000000000..f43f44c79c96d
--- /dev/null
+++ b/arch/arm/boot/dts/ti/omap/am335x-bone-hdmi-00a0.dtso
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 2017 Copyright (c) Seeed Technology Inc.  All right reserved.
+ * Author: Baozhu Zuo <zuobaozhu@gmail.com>
+ * Copyright (c) Bootlin 2026
+ *
+ * This device tree overlay is compatible with the BeagleBone Black, Green
+ * and their subversions.
+ */
+
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/pinctrl/am33xx.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+
+&{/} {
+	hdmi0: connector-hdmi {
+		compatible = "hdmi-connector";
+		label = "hdmi";
+		type = "a";
+		port {
+			hdmi_connector_in: endpoint {
+				remote-endpoint = <&it66121_out>;
+			};
+		};
+	};
+
+	clk_mcasp0_fixed: clk-mcasp0-fixed {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <24576000>;
+	};
+
+	clk_mcasp0: clk-mcasp0 {
+		#clock-cells = <0>;
+		compatible = "gpio-gate-clock";
+		clocks = <&clk_mcasp0_fixed>;
+		enable-gpios = <&gpio1 27 0>;
+	};
+
+	sound {
+		compatible = "simple-audio-card";
+		simple-audio-card,name = "TI BeagleBone Green HDMI cape";
+		simple-audio-card,format = "i2s";
+		simple-audio-card,bitclock-master = <&sound_master>;
+		simple-audio-card,frame-master = <&sound_master>;
+
+		sound_master: simple-audio-card,cpu {
+			sound-dai = <&mcasp0>;
+			clocks = <&clk_mcasp0>;
+		};
+
+		simple-audio-card,codec {
+			sound-dai = <&it66121>;
+		};
+	};
+};
+
+&am33xx_pinmux {
+	bb_lcd_pins: pinmux-bb-lcd-pins {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA0, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA1, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA2, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA3, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA4, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA5, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA6, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA7, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA8, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA9, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA10, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA11, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA12, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA13, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA14, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_DATA15, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_VSYNC, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_HSYNC, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_PCLK, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_LCD_AC_BIAS_EN, PIN_OUTPUT, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_ADVN_ALE, PIN_OUTPUT_PULLDOWN, MUX_MODE7)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_OEN_REN, PIN_OUTPUT_PULLDOWN, MUX_MODE7)
+			AM33XX_PADCONF(AM335X_PIN_GPMC_WEN, PIN_INPUT, MUX_MODE7)
+		>;
+	};
+	mcasp0_pins: mcasp0-pins {
+		pinctrl-single,pins = <
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_AHCLKX, PIN_INPUT_PULLUP, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_AHCLKR, PIN_OUTPUT_PULLDOWN, MUX_MODE2)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_FSX, PIN_OUTPUT_PULLUP, MUX_MODE0)
+			AM33XX_PADCONF(AM335X_PIN_MCASP0_ACLKX, PIN_OUTPUT_PULLDOWN, MUX_MODE0)
+		>;
+	};
+};
+
+&i2c2 {
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	it66121: it66121 {
+		compatible = "ite,it66121";
+		reg = <0x4d>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bb_lcd_pins>;
+
+		#sound-dai-cells = <0>;
+
+		interrupt-parent = <&gpio2>;
+		interrupts = <4 IRQ_TYPE_EDGE_RISING>;
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				it66121_in: endpoint {
+					bus-width = <24>;
+					remote-endpoint = <&lcdc_0>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+				it66121_out: endpoint {
+					remote-endpoint = <&hdmi_connector_in>;
+				};
+			};
+		};
+	};
+};
+
+&lcdc {
+	status = "okay";
+	blue-and-red-wiring = "straight";
+	port {
+		lcdc_0: endpoint@0 {
+			remote-endpoint = <&it66121_in>;
+		};
+	};
+};
+
+
+&mcasp0 {
+	status = "okay";
+	#sound-dai-cells = <0>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&mcasp0_pins>;
+	op-mode = <0>;
+	tdm-slots = <2>;
+	serial-dir = < 0 0 1 0 >;
+	tx-num-evt = <32>;
+	rx-num-evt = <32>;
+};
+

-- 
2.43.0