[Patch v3 0/3] Addition of new compatible for Exynos3250.

[Patch v3 0/3] Addition of new compatible for Exynos3250.

[Aakarsh Jain]

This patch series adds new compatible for Exynos3250 along with its
driver variant data for MFC v7 hardware.
Since,MFC v7 support was added for Exynos5420 and Exynos
3250 SoC with same compatible string "samsung,mfc-v7".As
both SoCs having different hardware properties and having
same compatible string for both SoCs doesn't seems to be correct.
So ,new compatible is added for Exynos3250 SOC which will
differentiate the node properties for both SoCs which
support MFC v7.

Changes since v2:
 - Addressed review comments from Krzysztof Kozlowski[1].

Changes since v1:
 - Addressed review comments from Marek Szyprowski[2].
 - Addressed review comments from Krzysztof Kozlowski[3].
 - Addressed review comments from Tommaso Merciai[4].

 1-https://patchwork.kernel.org/project/linux-media/patch/20221109035507.69086-1-aakarsh.jain@samsung.com/#25081990
 2-https://patchwork.kernel.org/project/linux-media/patch/20221102130602.48969-1-aakarsh.jain@samsung.com/#25072873
 3-https://patchwork.kernel.org/project/linux-media/patch/20221102130602.48969-1-aakarsh.jain@samsung.com/#25073109
 4-https://patchwork.kernel.org/project/linux-media/patch/20221102130602.48969-2-aakarsh.jain@samsung.com/#25072977

Aakarsh Jain (3):
  media: dt-bindings: s5p-mfc: Add new compatible string for Exynos3250
    SoC.
  media: s5p-mfc:Add variant data for MFC v7 hardware for Exynos 3250
    SoC
  ARM: dts: exynos: Rename compatible string property from version to
    SoC specific

 .../devicetree/bindings/media/s5p-mfc.txt       |  9 +++++----
 arch/arm/boot/dts/exynos3250.dtsi               |  2 +-
 .../media/platform/samsung/s5p-mfc/s5p_mfc.c    | 17 +++++++++++++++--
 3 files changed, 21 insertions(+), 7 deletions(-)

-- 
2.17.1

[Patch v3 1/3] media: dt-bindings: s5p-mfc: Add new compatible string for Exynos3250 SoC.

[Aakarsh Jain]

Since,MFC v7 support was added for Exynos5420 and Exynos
3250 SoC with same compatible string "samsung,mfc-v7".As
both SoCs having different hardware properties and having
same compatible string for both SoCs doesn't seems to be correct.
New compatible is added for Exynos3250 SOC which will
differentiate the node properties for both SoCs which
support MFC v7.

Reviewed-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com>
Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
---
 Documentation/devicetree/bindings/media/s5p-mfc.txt | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

We are already in process of converting this txt file to yaml.
https://patchwork.kernel.org/project/linux-media/patch/20221011122516.32135-2-aakarsh.jain@samsung.com/
Modifying this txt binding for completeness.

diff --git a/Documentation/devicetree/bindings/media/s5p-mfc.txt b/Documentation/devicetree/bindings/media/s5p-mfc.txt
index aa54c8159d9f..cb166654fa81 100644
--- a/Documentation/devicetree/bindings/media/s5p-mfc.txt
+++ b/Documentation/devicetree/bindings/media/s5p-mfc.txt
@@ -10,10 +10,11 @@ Required properties:
   - compatible : value should be either one among the following
 	(a) "samsung,mfc-v5" for MFC v5 present in Exynos4 SoCs
 	(b) "samsung,mfc-v6" for MFC v6 present in Exynos5 SoCs
-	(c) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
-	(d) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
-	(e) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
-	(f) "samsung,mfc-v10" for MFC v10 present in Exynos7880 SoC
+	(c) "samsung,exynos3250-mfc" for MFC v7 present in Exynos3250 SoC
+	(d) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
+	(e) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
+	(f) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
+	(g) "samsung,mfc-v10" for MFC v10 present in Exynos7880 SoC
 
   - reg : Physical base address of the IP registers and length of memory
 	  mapped region.
-- 
2.17.1

[Patch v3 2/3] media: s5p-mfc: Add variant data for MFC v7 hardware for Exynos 3250 SoC

[Aakarsh Jain]

commit "5441e9dafdfc6dc40fa" which adds mfc v7 support for
Exynos3250 and use the same compatible string as used by
Exynos5240 but both the IPs are a bit different in terms of
IP clock.
Lets add variant driver data based on the new compatible string
"samsung,exynos3250-mfc" for Exynos3250 SoC.

Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
Fixes: 5441e9dafdfc ("[media] s5p-mfc: Core support for MFC v7")
Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
---
 .../media/platform/samsung/s5p-mfc/s5p_mfc.c    | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c
index fca5c6405eec..007c7dbee037 100644
--- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c
@@ -1576,8 +1576,18 @@ static struct s5p_mfc_variant mfc_drvdata_v7 = {
 	.port_num	= MFC_NUM_PORTS_V7,
 	.buf_size	= &buf_size_v7,
 	.fw_name[0]     = "s5p-mfc-v7.fw",
-	.clk_names	= {"mfc", "sclk_mfc"},
-	.num_clocks	= 2,
+	.clk_names	= {"mfc"},
+	.num_clocks	= 1,
+};
+
+static struct s5p_mfc_variant mfc_drvdata_v7_3250 = {
+	.version        = MFC_VERSION_V7,
+	.version_bit    = MFC_V7_BIT,
+	.port_num       = MFC_NUM_PORTS_V7,
+	.buf_size       = &buf_size_v7,
+	.fw_name[0]     = "s5p-mfc-v7.fw",
+	.clk_names      = {"mfc", "sclk_mfc"},
+	.num_clocks     = 2,
 };
 
 static struct s5p_mfc_buf_size_v6 mfc_buf_size_v8 = {
@@ -1647,6 +1657,9 @@ static const struct of_device_id exynos_mfc_match[] = {
 	}, {
 		.compatible = "samsung,mfc-v7",
 		.data = &mfc_drvdata_v7,
+	}, {
+		.compatible = "samsung,exynos3250-mfc",
+		.data = &mfc_drvdata_v7_3250,
 	}, {
 		.compatible = "samsung,mfc-v8",
 		.data = &mfc_drvdata_v8,
-- 
2.17.1

[Patch v3 3/3] ARM: dts: exynos: Rename compatible string property from version to SoC specific

[Aakarsh Jain]

commit "752d3a23d1f68de87e3c" which adds MFC codec device node
for exynos3250 SoC. Since exynos3250.dtsi and exynos5420.dtsi are
using same compatible string as "samsung,mfc-v7" but their
node properties are different.As both SoCs have MFC v7 hardware
module but with different clock hierarchy and complexity.
So renaming compatible string from version specific to SoC based.

Reviewed-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com>
Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
---
 arch/arm/boot/dts/exynos3250.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi
index 326b9e0ed8d3..98105c64f7d9 100644
--- a/arch/arm/boot/dts/exynos3250.dtsi
+++ b/arch/arm/boot/dts/exynos3250.dtsi
@@ -485,7 +485,7 @@
 		};
 
 		mfc: codec@13400000 {
-			compatible = "samsung,mfc-v7";
+			compatible = "samsung,exynos3250-mfc";
 			reg = <0x13400000 0x10000>;
 			interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
 			clock-names = "mfc", "sclk_mfc";
-- 
2.17.1

Re: [Patch v3 0/3] Addition of new compatible for Exynos3250.

[Krzysztof Kozlowski]

On 11/11/2022 04:23, Aakarsh Jain wrote:
> This patch series adds new compatible for Exynos3250 along with its
> driver variant data for MFC v7 hardware.
> Since,MFC v7 support was added for Exynos5420 and Exynos
> 3250 SoC with same compatible string "samsung,mfc-v7".As
> both SoCs having different hardware properties and having
> same compatible string for both SoCs doesn't seems to be correct.
> So ,new compatible is added for Exynos3250 SOC which will
> differentiate the node properties for both SoCs which
> support MFC v7.
> 
> Changes since v2:
>  - Addressed review comments from Krzysztof Kozlowski[1].


What changed exactly?

> 
> Changes since v1:
>  - Addressed review comments from Marek Szyprowski[2].
>  - Addressed review comments from Krzysztof Kozlowski[3].
>  - Addressed review comments from Tommaso Merciai[4].

What changed exactly?

Best regards,
Krzysztof

Re: [Patch v3 1/3] media: dt-bindings: s5p-mfc: Add new compatible string for Exynos3250 SoC.

[Krzysztof Kozlowski]

On 11/11/2022 04:23, Aakarsh Jain wrote:
> Since,MFC v7 support was added for Exynos5420 and Exynos
> 3250 SoC with same compatible string "samsung,mfc-v7".As
> both SoCs having different hardware properties and having
> same compatible string for both SoCs doesn't seems to be correct.
> New compatible is added for Exynos3250 SOC which will
> differentiate the node properties for both SoCs which
> support MFC v7.

Subject: Drop full stop from subject.

Commit: This is not correct formatting, nor wrapping. In English after
every comma  or full stop there is a space.
Please wrap commit message according to Linux coding style / submission
process:
https://elixir.bootlin.com/linux/v5.18-rc4/source/Documentation/process/submitting-patches.rst#L586

Not "is added" but just "Add new compatible"
https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

But what is more important:

> 
> Reviewed-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com>
> Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
> ---
>  Documentation/devicetree/bindings/media/s5p-mfc.txt | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> We are already in process of converting this txt file to yaml.
> https://patchwork.kernel.org/project/linux-media/patch/20221011122516.32135-2-aakarsh.jain@samsung.com/
> Modifying this txt binding for completeness.
> 
> diff --git a/Documentation/devicetree/bindings/media/s5p-mfc.txt b/Documentation/devicetree/bindings/media/s5p-mfc.txt
> index aa54c8159d9f..cb166654fa81 100644
> --- a/Documentation/devicetree/bindings/media/s5p-mfc.txt
> +++ b/Documentation/devicetree/bindings/media/s5p-mfc.txt
> @@ -10,10 +10,11 @@ Required properties:
>    - compatible : value should be either one among the following
>  	(a) "samsung,mfc-v5" for MFC v5 present in Exynos4 SoCs
>  	(b) "samsung,mfc-v6" for MFC v6 present in Exynos5 SoCs
> -	(c) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
> -	(d) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
> -	(e) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
> -	(f) "samsung,mfc-v10" for MFC v10 present in Exynos7880 SoC
> +	(c) "samsung,exynos3250-mfc" for MFC v7 present in Exynos3250 SoC
> +	(d) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
> +	(e) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
> +	(f) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
> +	(g) "samsung,mfc-v10" for MFC v10 present in Exynos7880 SoC

I don't see here any improvements about which I commented since v1.

Best regards,
Krzysztof

Re: [Patch v3 3/3] ARM: dts: exynos: Rename compatible string property from version to SoC specific

[Krzysztof Kozlowski]

On 11/11/2022 04:23, Aakarsh Jain wrote:
> commit "752d3a23d1f68de87e3c" which adds MFC codec device node
> for exynos3250 SoC. Since exynos3250.dtsi and exynos5420.dtsi are
> using same compatible string as "samsung,mfc-v7" but their
> node properties are different.As both SoCs have MFC v7 hardware
> module but with different clock hierarchy and complexity.
> So renaming compatible string from version specific to SoC based.
> 
> Reviewed-by: Tommaso Merciai <tommaso.merciai@amarulasolutions.com>
> Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
> ---
>  arch/arm/boot/dts/exynos3250.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi
> index 326b9e0ed8d3..98105c64f7d9 100644
> --- a/arch/arm/boot/dts/exynos3250.dtsi
> +++ b/arch/arm/boot/dts/exynos3250.dtsi
> @@ -485,7 +485,7 @@
>  		};
>  
>  		mfc: codec@13400000 {
> -			compatible = "samsung,mfc-v7";
> +			compatible = "samsung,exynos3250-mfc";

No improvements. Changeset is non-bisectable. I said it in v1, then in
v2. So now third time... Don't send a new version if you are not going
to fix it or resolve discussion.

In cover letter you said "Addressed review comments from Krzysztof
Kozlowski", so please explain me, how did you resolve my comments about
fallback for this patch and for bindings patch?

Best regards,
Krzysztof

RE: [Patch v3 3/3] ARM: dts: exynos: Rename compatible string property from version to SoC specific

[Aakarsh Jain]

Hi Krzysztof,

> -----Original Message-----
> From: Krzysztof Kozlowski [mailto:krzysztof.kozlowski@linaro.org]
> Sent: 11 November 2022 13:41
> To: Aakarsh Jain <aakarsh.jain@samsung.com>; linux-arm-
> kernel@lists.infradead.org; linux-media@vger.kernel.org; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org
> Cc: m.szyprowski@samsung.com; andrzej.hajda@intel.com;
> mchehab@kernel.org; hverkuil-cisco@xs4all.nl;
> ezequiel@vanguardiasur.com.ar; jernej.skrabec@gmail.com;
> benjamin.gaignard@collabora.com; krzysztof.kozlowski+dt@linaro.org;
> stanimir.varbanov@linaro.org; dillon.minfei@gmail.com;
> david.plowman@raspberrypi.com; mark.rutland@arm.com;
> robh+dt@kernel.org; krzk+dt@kernel.org; andi@etezian.org;
> alim.akhtar@samsung.com; aswani.reddy@samsung.com;
> pankaj.dubey@samsung.com; smitha.t@samsung.com
> Subject: Re: [Patch v3 3/3] ARM: dts: exynos: Rename compatible string
> property from version to SoC specific
> 
> On 11/11/2022 04:23, Aakarsh Jain wrote:
> > commit "752d3a23d1f68de87e3c" which adds MFC codec device node for
> > exynos3250 SoC. Since exynos3250.dtsi and exynos5420.dtsi are using
> > same compatible string as "samsung,mfc-v7" but their node properties
> > are different.As both SoCs have MFC v7 hardware module but with
> > different clock hierarchy and complexity.
> > So renaming compatible string from version specific to SoC based.
> >
> > Reviewed-by: Tommaso Merciai
> <tommaso.merciai@amarulasolutions.com>
> > Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
> > Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
> > ---
> >  arch/arm/boot/dts/exynos3250.dtsi | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm/boot/dts/exynos3250.dtsi
> > b/arch/arm/boot/dts/exynos3250.dtsi
> > index 326b9e0ed8d3..98105c64f7d9 100644
> > --- a/arch/arm/boot/dts/exynos3250.dtsi
> > +++ b/arch/arm/boot/dts/exynos3250.dtsi
> > @@ -485,7 +485,7 @@
> >  		};
> >
> >  		mfc: codec@13400000 {
> > -			compatible = "samsung,mfc-v7";
> > +			compatible = "samsung,exynos3250-mfc";
> 
> No improvements. Changeset is non-bisectable. I said it in v1, then in v2. So
> now third time... Don't send a new version if you are not going to fix it or
> resolve discussion.
> 
My bad, misunderstood, now I understood your concerns around bisectability.

I hope you mean the below:
------
diff --git a/Documentation/devicetree/bindings/media/s5p-mfc.txt b/Documentation/devicetree/bindings/media/s5p-mfc.txt
index cb166654fa81..734e53445eb5 100644
--- a/Documentation/devicetree/bindings/media/s5p-mfc.txt
+++ b/Documentation/devicetree/bindings/media/s5p-mfc.txt
@@ -10,7 +10,8 @@ Required properties:
   - compatible : value should be either one among the following
        (a) "samsung,mfc-v5" for MFC v5 present in Exynos4 SoCs
        (b) "samsung,mfc-v6" for MFC v6 present in Exynos5 SoCs
-       (c) "samsung,exynos3250-mfc" for MFC v7 present in Exynos3250 SoC
+       (c) "samsung,exynos3250-mfc","samsung,mfc-v7" for MFC v7
+            variant present in Exynos3250 SoC.
        (d) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
        (e) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
        (f) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi
index 98105c64f7d9..a2d6ee7fff08 100644
--- a/arch/arm/boot/dts/exynos3250.dtsi
+++ b/arch/arm/boot/dts/exynos3250.dtsi
@@ -485,7 +485,7 @@
                };

                mfc: codec@13400000 {
-                       compatible = "samsung,exynos3250-mfc";
+                       compatible = "samsung,exynos3250-mfc", "samsung,mfc-v7";
                        reg = <0x13400000 0x10000>;
                        interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
                        clock-names = "mfc", "sclk_mfc";
-----

Where mfc-v7 will be used as fallback for the older kernel which might use new dtb.

Let me know if this is not what you meant or am I still missing something?


> In cover letter you said "Addressed review comments from Krzysztof
> Kozlowski", so please explain me, how did you resolve my comments about
> fallback for this patch and for bindings patch?
> 
My bad, I just explained the misunderstanding above.

> Best regards,
> Krzysztof

Re: [Patch v3 3/3] ARM: dts: exynos: Rename compatible string property from version to SoC specific

[Krzysztof Kozlowski]

On 11/11/2022 10:22, Aakarsh Jain wrote:
> Hi Krzysztof,
> 
>> -----Original Message-----
>> From: Krzysztof Kozlowski [mailto:krzysztof.kozlowski@linaro.org]
>> Sent: 11 November 2022 13:41
>> To: Aakarsh Jain <aakarsh.jain@samsung.com>; linux-arm-
>> kernel@lists.infradead.org; linux-media@vger.kernel.org; linux-
>> kernel@vger.kernel.org; devicetree@vger.kernel.org
>> Cc: m.szyprowski@samsung.com; andrzej.hajda@intel.com;
>> mchehab@kernel.org; hverkuil-cisco@xs4all.nl;
>> ezequiel@vanguardiasur.com.ar; jernej.skrabec@gmail.com;
>> benjamin.gaignard@collabora.com; krzysztof.kozlowski+dt@linaro.org;
>> stanimir.varbanov@linaro.org; dillon.minfei@gmail.com;
>> david.plowman@raspberrypi.com; mark.rutland@arm.com;
>> robh+dt@kernel.org; krzk+dt@kernel.org; andi@etezian.org;
>> alim.akhtar@samsung.com; aswani.reddy@samsung.com;
>> pankaj.dubey@samsung.com; smitha.t@samsung.com
>> Subject: Re: [Patch v3 3/3] ARM: dts: exynos: Rename compatible string
>> property from version to SoC specific
>>
>> On 11/11/2022 04:23, Aakarsh Jain wrote:
>>> commit "752d3a23d1f68de87e3c" which adds MFC codec device node for
>>> exynos3250 SoC. Since exynos3250.dtsi and exynos5420.dtsi are using
>>> same compatible string as "samsung,mfc-v7" but their node properties
>>> are different.As both SoCs have MFC v7 hardware module but with
>>> different clock hierarchy and complexity.
>>> So renaming compatible string from version specific to SoC based.
>>>
>>> Reviewed-by: Tommaso Merciai
>> <tommaso.merciai@amarulasolutions.com>
>>> Suggested-by: Alim Akhtar <alim.akhtar@samsung.com>
>>> Signed-off-by: Aakarsh Jain <aakarsh.jain@samsung.com>
>>> ---
>>>  arch/arm/boot/dts/exynos3250.dtsi | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos3250.dtsi
>>> b/arch/arm/boot/dts/exynos3250.dtsi
>>> index 326b9e0ed8d3..98105c64f7d9 100644
>>> --- a/arch/arm/boot/dts/exynos3250.dtsi
>>> +++ b/arch/arm/boot/dts/exynos3250.dtsi
>>> @@ -485,7 +485,7 @@
>>>  		};
>>>
>>>  		mfc: codec@13400000 {
>>> -			compatible = "samsung,mfc-v7";
>>> +			compatible = "samsung,exynos3250-mfc";
>>
>> No improvements. Changeset is non-bisectable. I said it in v1, then in v2. So
>> now third time... Don't send a new version if you are not going to fix it or
>> resolve discussion.
>>
> My bad, misunderstood, now I understood your concerns around bisectability.
> 
> I hope you mean the below:
> ------
> diff --git a/Documentation/devicetree/bindings/media/s5p-mfc.txt b/Documentation/devicetree/bindings/media/s5p-mfc.txt
> index cb166654fa81..734e53445eb5 100644
> --- a/Documentation/devicetree/bindings/media/s5p-mfc.txt
> +++ b/Documentation/devicetree/bindings/media/s5p-mfc.txt
> @@ -10,7 +10,8 @@ Required properties:
>    - compatible : value should be either one among the following
>         (a) "samsung,mfc-v5" for MFC v5 present in Exynos4 SoCs
>         (b) "samsung,mfc-v6" for MFC v6 present in Exynos5 SoCs
> -       (c) "samsung,exynos3250-mfc" for MFC v7 present in Exynos3250 SoC
> +       (c) "samsung,exynos3250-mfc","samsung,mfc-v7" for MFC v7
> +            variant present in Exynos3250 SoC.
>         (d) "samsung,mfc-v7" for MFC v7 present in Exynos5420 SoC
>         (e) "samsung,mfc-v8" for MFC v8 present in Exynos5800 SoC
>         (f) "samsung,exynos5433-mfc" for MFC v8 present in Exynos5433 SoC
> diff --git a/arch/arm/boot/dts/exynos3250.dtsi b/arch/arm/boot/dts/exynos3250.dtsi
> index 98105c64f7d9..a2d6ee7fff08 100644
> --- a/arch/arm/boot/dts/exynos3250.dtsi
> +++ b/arch/arm/boot/dts/exynos3250.dtsi
> @@ -485,7 +485,7 @@
>                 };
> 
>                 mfc: codec@13400000 {
> -                       compatible = "samsung,exynos3250-mfc";
> +                       compatible = "samsung,exynos3250-mfc", "samsung,mfc-v7";
>                         reg = <0x13400000 0x10000>;
>                         interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
>                         clock-names = "mfc", "sclk_mfc";
> -----
> 
> Where mfc-v7 will be used as fallback for the older kernel which might use new dtb.
> 
> Let me know if this is not what you meant or am I still missing something?

Yes, this is what I meant. Thanks.

Best regards,
Krzysztof