[PATCH] arm64: dts: exynos850: Add GPU/Mali Bifrost node

[PATCH] arm64: dts: exynos850: Add GPU/Mali Bifrost node

[Thomas Turner]

This can provide basic GPU functionality for the Exynos850 platform.
Tested on the SM-A217F device. Does not provide support for temperature
throttling, DVFS, power domains, governor support, boosting and voltage
control. Once PMIC is properly implemented, support will hopefully
increase. However the panfrost driver probes, the Mali-G52 GPU
initializes and the core clock is set-up.

Signed-off-by: Thomas Turner <tturner@lineageos.org>
---
 arch/arm64/boot/dts/exynos/exynos850.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index 3881f573ec08..8ed85c125030 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -296,6 +296,18 @@ cmu_g3d: clock-controller@11400000 {
 			clock-names = "oscclk", "dout_g3d_switch";
 		};
 
+		gpu: gpu@11500000 {
+			compatible = "samsung,exynos850-mali", "arm,mali-bifrost";
+			reg = <0x11500000 0x5000>;
+			interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 127 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "job", "mmu", "gpu";
+			clocks = <&cmu_g3d CLK_GOUT_G3D_GPU_CLK>;
+			clock-names = "core";
+			status = "disabled";
+		};
+
 		cmu_apm: clock-controller@11800000 {
 			compatible = "samsung,exynos850-cmu-apm";
 			reg = <0x11800000 0x8000>;
-- 
2.47.3

Re: [PATCH] arm64: dts: exynos850: Add GPU/Mali Bifrost node

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The newly introduced compatible string 'samsung,exynos850-mali' is not documented in the device tree bindings schema.
--

--- Patch [1]: [PATCH] arm64: dts: exynos850: Add GPU/Mali Bifrost node ---
commit 358cd68635088d124d51d9f2284625ff11e03e28
Author: Thomas Turner <tturner@lineageos.org>

arm64: dts: exynos850: Add GPU/Mali Bifrost node

This commit adds a GPU node for the Exynos850 platform to provide basic GPU
functionality. The panfrost driver can probe the Mali-G52 GPU with core
clocks set up, though advanced power management features are not yet
supported.

> diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
> index 3881f573ec08d..8ed85c125030a 100644
> --- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
> @@ -296,6 +296,18 @@ cmu_g3d: clock-controller@11400000 {
>  			clock-names = "oscclk", "dout_g3d_switch";
>  		};
>  
> +		gpu: gpu@11500000 {
> +			compatible = "samsung,exynos850-mali", "arm,mali-bifrost";

[Severity: Low]
Is the new compatible string samsung,exynos850-mali documented in the
device tree bindings schema?

It appears this SoC-specific compatible string lacks a corresponding entry in
the dt-bindings documentation (e.g.
Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml). This will
likely cause make dtbs_check to emit warnings or fail validation for this
device tree file.

> +			reg = <0x11500000 0x5000>;
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260820133556.76300-1-tturner@lineageos.org?part=1

Re: [PATCH] arm64: dts: exynos850: Add GPU/Mali Bifrost node

[Krzysztof Kozlowski]

On 20/08/2026 15:35, Thomas Turner wrote:
> This can provide basic GPU functionality for the Exynos850 platform.
> Tested on the SM-A217F device. Does not provide support for temperature

How? The node is disabled.

Please respond to actual comments you received before.

Also, you need to version your patches correctly. This is v2. You also
need changelog under ---.

Best regards,
Krzysztof

[PATCH v2 0/2] Exynos850 GPU support

[Thomas Turner]

Hi all,
This is my first time sending patches to linux so apologies for
mistakes. This series provides basic GPU support to the Exynos850
platform, making use of the Mali G52 GPU through the panfrost driver.

Thomas Turner (2):
  dt-bindings: gpu: arm,mali-bifrost: add exynos850-mali compatible
  arm64: dts: exynos850: Add GPU/Mali Bifrost node

 .../devicetree/bindings/gpu/arm,mali-bifrost.yaml    |  1 +
 arch/arm64/boot/dts/exynos/exynos850.dtsi            | 12 ++++++++++++
 2 files changed, 13 insertions(+)

-- 
2.47.3

[PATCH v2 1/2] dt-bindings: gpu: arm,mali-bifrost: add exynos850-mali compatible

[Thomas Turner]

Exynos850 SoC uses the ARM Mali G52 GPU, document its compatible
string with the appropriate fallback.

Signed-off-by: Thomas Turner <tturner@lineageos.org>
---
 Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
index 9db9f84ad964..ece2b637cd41 100644
--- a/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
+++ b/Documentation/devicetree/bindings/gpu/arm,mali-bifrost.yaml
@@ -34,6 +34,7 @@ properties:
               - rockchip,rk3562-mali
               - rockchip,rk3568-mali
               - rockchip,rk3576-mali
+              - samsung,exynos850-mali
           - const: arm,mali-bifrost # Mali Bifrost GPU model/revision is fully discoverable
       - items:
           - enum:
-- 
2.47.3

[PATCH v2 2/2] arm64: dts: exynos850: Add GPU/Mali Bifrost node

[Thomas Turner]

This can provide basic GPU functionality for the Exynos850 platform.
Tested on the SM-A217F device. Does not provide support for temperature
throttling, DVFS, power domains, governor support, boosting and voltage
control. Once PMIC is properly implemented, support will hopefully
increase. However the panfrost driver probes, the Mali-G52 GPU
initializes and the core clock is set-up.

Signed-off-by: Thomas Turner <tturner@lineageos.org>
---
 arch/arm64/boot/dts/exynos/exynos850.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index 3881f573ec08..8ed85c125030 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -296,6 +296,18 @@ cmu_g3d: clock-controller@11400000 {
 			clock-names = "oscclk", "dout_g3d_switch";
 		};
 
+		gpu: gpu@11500000 {
+			compatible = "samsung,exynos850-mali", "arm,mali-bifrost";
+			reg = <0x11500000 0x5000>;
+			interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 127 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "job", "mmu", "gpu";
+			clocks = <&cmu_g3d CLK_GOUT_G3D_GPU_CLK>;
+			clock-names = "core";
+			status = "disabled";
+		};
+
 		cmu_apm: clock-controller@11800000 {
 			compatible = "samsung,exynos850-cmu-apm";
 			reg = <0x11800000 0x8000>;
-- 
2.47.3

Re: [PATCH v2 0/2] Exynos850 GPU support

[Krzysztof Kozlowski]

On 20/08/2026 16:23, Thomas Turner wrote:
> Hi all,
> This is my first time sending patches to linux so apologies for
> mistakes. This series provides basic GPU support to the Exynos850
> platform, making use of the Mali G52 GPU through the panfrost driver.
> 

Again: slow down.

Why does this appear under empty subject thread?

Best regards,
Krzysztof

Re: [PATCH v2 0/2] Exynos850 GPU support

[thomas_turner@talktalk.net]

Apologies, I think I am missing the --thread parameter. The command I ran was

git send-email --in-reply-to='<GVYP280MB12139AB976CA7ACF49FEB768A1A52@GVYP280MB1213.SWEP280.PROD.OUTLOOK.COM>' \
    --to='etc' \
    --cc='etc' \
    v2-000*.patch


I want to avoid spamming the mailing list with null information so I would appreciate some guidance on what I am doing wrong. In regards to your comment, I left it disabled as I was initially unsure whether the E850-96 Board uses Mali G52, however it seems all exynos850 devices share the same GPU, would it be better to have as status="okay"  ?

As for the comments I believe I already responded to them but I am testing this on the Samsung Galaxy A21s and here are some logs I pulled.
[    0.230437] panfrost 11500000.gpu: clock rate = 377000000
[    0.230863] panfrost 11500000.gpu: mali-g52 id 0x7212 major 0x0 minor 0x0 status 0x0
[    0.230945] panfrost 11500000.gpu: features: 00000000,00000df7, issues: 00000000,00000400
[    0.231026] panfrost 11500000.gpu: Features: L2:0x07100206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
[    0.231137] panfrost 11500000.gpu: shader_present=0x1 l2_present=0x1
[    0.232552] panfrost 11500000.gpu: [drm] Using Transparent Hugepage
[    0.233172] [drm] Initialized panfrost 1.6.0 for 11500000.gpu on minor 0

________________________________________
From: thomas_turner@talktalk.net <thomas_turner@talktalk.net>
Sent: Thursday, August 20, 2026 7:39 AM
To: Krzysztof Kozlowski; Thomas Turner
Cc: semen.protsenko@linaro.org; robh@kernel.org; krzk+dt@kernel.org; conor+dt@kernel.org; peter.griffin@linaro.org; alim.akhtar@samsung.com; linux-arm-kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] Exynos850 GPU support

Apologies, I think I am missing the --thread parameter. The command I ran was

git send-email --in-reply-to='<GVYP280MB12139AB976CA7ACF49FEB768A1A52@GVYP280MB1213.SWEP280.PROD.OUTLOOK.COM>' \
    --to='etc' \
    --cc='etc' \
    v2-000*.patch


I want to avoid spamming the mailing list with null information so I would appreciate some guidance on what I am doing wrong. In regards to your comment, I left it disabled as I was initially unsure whether the E850-96 Board uses Mali G52, however it seems all exynos850 devices share the same GPU, would it be better to have as status="okay"  ?

As for the comments I believe I already responded to them but I am testing this on the Samsung Galaxy A21s and here are some logs I pulled.
[    0.230437] panfrost 11500000.gpu: clock rate = 377000000
[    0.230863] panfrost 11500000.gpu: mali-g52 id 0x7212 major 0x0 minor 0x0 status 0x0
[    0.230945] panfrost 11500000.gpu: features: 00000000,00000df7, issues: 00000000,00000400
[    0.231026] panfrost 11500000.gpu: Features: L2:0x07100206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
[    0.231137] panfrost 11500000.gpu: shader_present=0x1 l2_present=0x1
[    0.232552] panfrost 11500000.gpu: [drm] Using Transparent Hugepage
[    0.233172] [drm] Initialized panfrost 1.6.0 for 11500000.gpu on minor 0

________________________________________
From: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Sent: Thursday, August 20, 2026 7:28 AM
To: Thomas Turner; krzysztof.kozlowski@oss.qualcomm.com
Cc: semen.protsenko@linaro.org; robh@kernel.org; krzk+dt@kernel.org; conor+dt@kernel.org; peter.griffin@linaro.org; alim.akhtar@samsung.com; linux-arm-kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org; devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] Exynos850 GPU support

On 20/08/2026 16:23, Thomas Turner wrote:
> Hi all,
> This is my first time sending patches to linux so apologies for
> mistakes. This series provides basic GPU support to the Exynos850
> platform, making use of the Mali G52 GPU through the panfrost driver.
>

Again: slow down.

Why does this appear under empty subject thread?

Best regards,
Krzysztof

Re: [PATCH v2 0/2] Exynos850 GPU support

[Krzysztof Kozlowski]

On 20/08/2026 18:22, thomas_turner@talktalk.net wrote:
> 
> Apologies, I think I am missing the --thread parameter. The command I ran was
> 
> git send-email --in-reply-to='<GVYP280MB12139AB976CA7ACF49FEB768A1A52@GVYP280MB1213.SWEP280.PROD.OUTLOOK.COM>' \

You almost never use this parameter.

git format patch; scripts/getmaintainers; git send email

Or just use b4 as all recent guides are asking
https://www.linaro.org/blog/becoming-a-kernel-developer-part1-posting-your-first-patch/

Please read:
https://subspace.kernel.org/etiquette.html


Best regards,
Krzysztof

Re: [PATCH v2 0/2] Exynos850 GPU support

[Thomas Turner]

Hi,

 > Can you please tell us a bit about how you tested this patch, and on
 > which board? As DPU is not currently enabled on Exynos850 SoC, I'm not
 > sure how exactly GPU can be useful. If you have a use case or a
 > testing procedure we can run on the E850-96 board, please share.

I tested this patch by running phosh (PostMarketOS) on the Samsung 
Galaxy A21s device, in my tests logs indicated that the GPU hardware was 
probed successfully and things were working. As for DPU, I simply 
enabled CONFIG_DRM_SIMPLEDRM and that was enough since the bootloader 
configured the related DPU bits. Since I don't own the e850-96 dev board 
myself a testing procedure you could do is.

1) Set status="okay"
2) Enable CONFIG_DRM_SIMPLEDRM and CONFIG_DRM_PANFROST
3) Try and boot some form of GUI and compare logs from dmesg with mine.
4) NOTE: we set up fixed regulators during our testing with some support 
from a secondary bootloader, however it should work with dummy regulators.

 > Would be nice to have a more detailed commit message overall. In
 > addition to the above, it probably makes sense to also discuss current
 > limitations. E.g. thermal, PD, and DVFS, which are enabled in the
 > downstream kernel's GPU node [1].

Yes, I have updated the commit message in v2 of the patch series to be 
more descriptive about what does and does not work, I hope that level of 
detail is sufficient but feel free to point out any sections I may have 
missed.

 > How? The node is disabled.

Not sure if the e850-96 device supports this functionality so for the 
mean time I left it as "disabled", but would be interesting to see if 
Sam or Alexey could test it too.

 > Also, you need to version your patches correctly. This is v2. You also
 > need changelog under ---.

Again, sorry for not including this I am still getting my head around 
the process, but in the v3 of the patch series I will make sure to 
include it.

 > You almost never use this parameter.
 > git format patch; scripts/getmaintainers; git send email

Got it thanks, Sam has been helping me with some of the kernel etiquette 
and procedures in a private thread so hopefully the next patch set 
should be lots clearer :).


One other thing I wanted to ask, do you think it would be best to 
include the logs about the GPU probing in the commit message of v3?

In the next patch version I am going to reword the commit msg to be more 
precise, i.e Add nodes for GPU. Can add more information about how I 
tested it and possibly logs from dmesg.

Cheers,
Tom.

Re: [PATCH v2 0/2] Exynos850 GPU support

[Alexey Klimov]

On Thu Aug 20, 2026 at 3:23 PM BST, Thomas Turner wrote:
> Hi all,

Hi Thomas,

On the next submission, could you please also add my email
alexey.klimov@linaro.org to c/c list?
It is interesting topic.

Offtopic: I have working patches that enable cpu idle states on Exynos850
but they are not upstreameable due to PSCI (needs some argument
shift in one of the PSCI calls due to messed up MPIDRs).
If you will be interested to test/use that, please let me know.

> This is my first time sending patches to linux so apologies for
> mistakes. This series provides basic GPU support to the Exynos850
> platform, making use of the Mali G52 GPU through the panfrost driver.

Best regards,
Alexey

Re: [PATCH v2 0/2] Exynos850 GPU support

[Thomas Turner]

Hi Alexey,

On 25/08/2026 16:50, Alexey Klimov wrote:
> 
> Hi Thomas,
> 
> On the next submission, could you please also add my email
> alexey.klimov@linaro.org to c/c list?
> It is interesting topic.

Sure thing.
> Offtopic: I have working patches that enable cpu idle states on Exynos850
> but they are not upstreameable due to PSCI (needs some argument
> shift in one of the PSCI calls due to messed up MPIDRs).
> If you will be interested to test/use that, please let me know.
> 

Absolutely would be interested to try and test that on my ERD850 device,
feel free to send patches/instructions my way.

On another side note, I noticed that on the e850-96 you setup basic PMIC
functionality in u-boot, on ERD850 we also do a similar thing via a
secondary bootloader (uniLoader), was curious to know whether you or Sam
have tried implementing PMIC capabilities into the Linux kernel at all and
if so how successful or unsuccessful has it been?

Best Regards,
Tom

Re:

[Thomas Turner]

Hi Sam and Alexey,

On 19/08/2026 20:51, Sam Protsenko wrote:
> Can you please tell us a bit about how you tested this patch, and on
> which board? As DPU is not currently enabled on Exynos850 SoC, I'm not
> sure how exactly GPU can be useful. If you have a use case or a
> testing procedure we can run on the E850-96 board, please share.
> 

Sam, Alexey could you please test GPU on the E850-96 board by following
these instructions:

1) Apply this patch series locally
2) Change status="disabled"; to status="okay";
3) Make sure these configs are enabled:
CONFIG_DRM_SIMPLEDRM=y
CONFIG_DRM_PANFROST=y
4) In terms of regulators we set up a basic mali regulator via our
secondary bootloader [1] and configured with this dts setup [2], NOTE
you may be able to get away with a dummy regulator so try that first.
If not I am sure you can replicate something simple with u-boot PMIC.
5) Boot a GUI, I saw Debian was used for the bring-up, that should work
6) Run the following command:
$ dmesg | grep "panfrost"
7) Compare that to the output at [3]

I hope these instructions make sense, but feel free to send any queries
my way.

Best Regards,
Tom

[1] https://github.com/samsungexynos850/uniLoader/commit/6a2ed2d97aaf1616e581d0979f9e56a046093e15
[2] https://github.com/samsungexynos850/linux/commit/68442271304b7c7a410d85118e85df67bcda108a
[3] https://gist.github.com/DaemonMCR/63fa564483202642d6d66e628b8e6c90