[PATCH v3 0/3] STM32 warning cleanup

[PATCH v3 0/3] STM32 warning cleanup

[Raphael Gallais-Pou]

This serie aims to reduce the number of device-tree warnings of
following boards :

  - STM32F469-DISCO
  - STM32MP15*

Those warnings were appearing either during build or when checking
dt-bindings and concern mostly LTDC and DSI IPs. They were due to the
following cases:

  - 'panel-dsi@0' instead of 'panel@0' according to the YAML
  - unnecessary #address-cells and #size-cells properties
  - residual 'reg' field on single endpoints

First patch fixes stm32f469-disco device-tree.

Second patch fixes st,stm32-dsi.yaml dt-bindings.

Third patch fixes stm32mp15* device-trees.

Changes since v2:
	* Added changelog
	* Enhanced commit descriptions

Changes since v1:
	* Added DSI subnode name change
	* Included stm32f469-disco DT in the cleanup
	* Included YAML fix to prevent regression

Raphael Gallais-Pou (3):
  ARM: dts: stm32: fix warnings on stm32f469-disco board
  dt-bindings: display: st,stm32-dsi: Remove unnecessary fields
  ARM: dts: stm32: fix several DT warnings on stm32mp15

 .../devicetree/bindings/display/st,stm32-dsi.yaml      |  2 --
 arch/arm/boot/dts/stm32f469-disco.dts                  |  4 ++--
 arch/arm/boot/dts/stm32mp151.dtsi                      |  5 -----
 arch/arm/boot/dts/stm32mp157.dtsi                      |  7 -------
 .../dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts    |  6 ++++--
 .../boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts   |  6 ++++--
 .../stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts  |  3 +--
 arch/arm/boot/dts/stm32mp157c-dk2.dts                  |  8 ++++++++
 arch/arm/boot/dts/stm32mp157c-ev1.dts                  | 10 +++++++---
 arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts              |  3 +--
 arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi     |  6 +-----
 arch/arm/boot/dts/stm32mp15xx-dkx.dtsi                 |  3 +--
 12 files changed, 29 insertions(+), 34 deletions(-)

-- 
2.25.1

[PATCH v3 1/3] ARM: dts: stm32: fix warnings on stm32f469-disco board

[Raphael Gallais-Pou]

Several warnings appear when building and checking stm32f429 device-tree:

arch/arm/boot/dts/stm32f469-disco.dts:182.28-184.5: Warning (unit_address_vs_reg):
/soc/display-controller@40016800/port/endpoint@0: node has a unit name, but no reg or ranges property

.../arch/arm/boot/dts/stm32f469-disco.dtb: dsi@40016c00: Unevaluated properties are not allowed ('panel-dsi@0' was unexpected)
	From schema: .../Documentation/devicetree/bindings/display/st,stm32-dsi.yaml

Fix those.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
---
 arch/arm/boot/dts/stm32f469-disco.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/stm32f469-disco.dts b/arch/arm/boot/dts/stm32f469-disco.dts
index 5a0daf8e8b11..cbbd521bf010 100644
--- a/arch/arm/boot/dts/stm32f469-disco.dts
+++ b/arch/arm/boot/dts/stm32f469-disco.dts
@@ -160,7 +160,7 @@ dsi_out: endpoint {
 		};
 	};
 
-	panel-dsi@0 {
+	panel@0 {
 		compatible = "orisetech,otm8009a";
 		reg = <0>; /* dsi virtual channel (0..3) */
 		reset-gpios = <&gpioh 7 GPIO_ACTIVE_LOW>;
@@ -179,7 +179,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_out_dsi: endpoint@0 {
+		ltdc_out_dsi: endpoint {
 			remote-endpoint = <&dsi_in>;
 		};
 	};
-- 
2.25.1

Re: [PATCH v3 1/3] ARM: dts: stm32: fix warnings on stm32f469-disco board

[Marek Vasut]

On 5/17/23 16:35, Raphael Gallais-Pou wrote:
> Several warnings appear when building and checking stm32f429 device-tree:
> 
> arch/arm/boot/dts/stm32f469-disco.dts:182.28-184.5: Warning (unit_address_vs_reg):
> /soc/display-controller@40016800/port/endpoint@0: node has a unit name, but no reg or ranges property
> 
> .../arch/arm/boot/dts/stm32f469-disco.dtb: dsi@40016c00: Unevaluated properties are not allowed ('panel-dsi@0' was unexpected)
> 	From schema: .../Documentation/devicetree/bindings/display/st,stm32-dsi.yaml
> 
> Fix those.
> 
> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>

Reviewed-by: Marek Vasut <marex@denx.de>

[PATCH v3 2/3] dt-bindings: display: st,stm32-dsi: Remove unnecessary fields

[Raphael Gallais-Pou]

"#address-cells" and "#size-cells" are two properties that are not
mandatory. For instance, the DSI could refer to a bridge outside the scope
of the node rather than include a 'panel@0' subnode. By doing so, address
and size fields become then unnecessary, creating a warning at build time.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
---
 Documentation/devicetree/bindings/display/st,stm32-dsi.yaml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/st,stm32-dsi.yaml b/Documentation/devicetree/bindings/display/st,stm32-dsi.yaml
index c488308d7be1..53560052aaf0 100644
--- a/Documentation/devicetree/bindings/display/st,stm32-dsi.yaml
+++ b/Documentation/devicetree/bindings/display/st,stm32-dsi.yaml
@@ -74,8 +74,6 @@ properties:
                   - const: 2
 
 required:
-  - "#address-cells"
-  - "#size-cells"
   - compatible
   - reg
   - clocks
-- 
2.25.1

Re: [PATCH v3 2/3] dt-bindings: display: st,stm32-dsi: Remove unnecessary fields

[Conor Dooley]

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On Wed, May 17, 2023 at 04:35:41PM +0200, Raphael Gallais-Pou wrote:
> "#address-cells" and "#size-cells" are two properties that are not
> mandatory. For instance, the DSI could refer to a bridge outside the scope
> of the node rather than include a 'panel@0' subnode. By doing so, address
> and size fields become then unnecessary, creating a warning at build time.
> 
> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>

Acked-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

[-- Attachment #2: signature.asc --]
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Re: [PATCH v3 2/3] dt-bindings: display: st,stm32-dsi: Remove unnecessary fields

[Marek Vasut]

On 5/17/23 16:35, Raphael Gallais-Pou wrote:
> "#address-cells" and "#size-cells" are two properties that are not
> mandatory. For instance, the DSI could refer to a bridge outside the scope
> of the node rather than include a 'panel@0' subnode. By doing so, address
> and size fields become then unnecessary, creating a warning at build time.
> 
> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>

Reviewed-by: Marek Vasut <marex@denx.de>

[PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Raphael Gallais-Pou]

Several warnings regarding LTDC and DSI on stm32mp15* device-trees remains.

Those concern:
  * "#size-cells" and "#address-cells" wrongly used
  * residual "reg" property appearing on endpoints where it could be
    avoided
  * Changed 'panel-dsi@0' to 'panel@0' according to dsi-controller.yaml

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
---
 arch/arm/boot/dts/stm32mp151.dtsi                      |  5 -----
 arch/arm/boot/dts/stm32mp157.dtsi                      |  7 -------
 .../dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts    |  6 ++++--
 .../boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts   |  6 ++++--
 .../stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts  |  3 +--
 arch/arm/boot/dts/stm32mp157c-dk2.dts                  |  8 ++++++++
 arch/arm/boot/dts/stm32mp157c-ev1.dts                  | 10 +++++++---
 arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts              |  3 +--
 arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi     |  6 +-----
 arch/arm/boot/dts/stm32mp15xx-dkx.dtsi                 |  3 +--
 10 files changed, 27 insertions(+), 30 deletions(-)

diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
index a98ae58e2c1c..bf3830dca742 100644
--- a/arch/arm/boot/dts/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/stm32mp151.dtsi
@@ -1529,11 +1529,6 @@ ltdc: display-controller@5a001000 {
 			clock-names = "lcd";
 			resets = <&rcc LTDC_R>;
 			status = "disabled";
-
-			port {
-				#address-cells = <1>;
-				#size-cells = <0>;
-			};
 		};
 
 		iwdg2: watchdog@5a002000 {
diff --git a/arch/arm/boot/dts/stm32mp157.dtsi b/arch/arm/boot/dts/stm32mp157.dtsi
index 54e73ccea446..5e733cd16ff9 100644
--- a/arch/arm/boot/dts/stm32mp157.dtsi
+++ b/arch/arm/boot/dts/stm32mp157.dtsi
@@ -24,14 +24,7 @@ dsi: dsi@5a000000 {
 			clock-names = "pclk", "ref", "px_clk";
 			resets = <&rcc DSI_R>;
 			reset-names = "apb";
-			#address-cells = <1>;
-			#size-cells = <0>;
 			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-			};
 		};
 	};
 };
diff --git a/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts b/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts
index 9a2a4bc7d079..4279b26547df 100644
--- a/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts
+++ b/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-ctouch2-of10.dts
@@ -49,6 +49,9 @@ &dsi {
 	phy-dsi-supply = <&reg18>;
 
 	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
 		port@0 {
 			reg = <0>;
 			dsi_in: endpoint {
@@ -104,8 +107,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&dsi_in>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts b/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts
index 390ee8c05754..efba54289820 100644
--- a/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts
+++ b/arch/arm/boot/dts/stm32mp157a-icore-stm32mp1-edimm2.2.dts
@@ -49,6 +49,9 @@ &dsi {
 	phy-dsi-supply = <&reg18>;
 
 	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
 		port@0 {
 			reg = <0>;
 			dsi_in_ltdc: endpoint {
@@ -104,8 +107,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_out_dsi: endpoint@0 {
-			reg = <0>;
+		ltdc_out_dsi: endpoint {
 			remote-endpoint = <&dsi_in_ltdc>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts b/arch/arm/boot/dts/stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts
index 0d7560ba2950..5116a7785201 100644
--- a/arch/arm/boot/dts/stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts
+++ b/arch/arm/boot/dts/stm32mp157a-microgea-stm32mp1-microdev2.0-of7.dts
@@ -81,8 +81,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&panel_in>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp157c-dk2.dts b/arch/arm/boot/dts/stm32mp157c-dk2.dts
index ab13e340f4ef..4bef2300ed7c 100644
--- a/arch/arm/boot/dts/stm32mp157c-dk2.dts
+++ b/arch/arm/boot/dts/stm32mp157c-dk2.dts
@@ -31,10 +31,15 @@ &cryp1 {
 };
 
 &dsi {
+	#address-cells = <1>;
+	#size-cells = <0>;
 	status = "okay";
 	phy-dsi-supply = <&reg18>;
 
 	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
 		port@0 {
 			reg = <0>;
 			dsi_in: endpoint {
@@ -82,6 +87,9 @@ &ltdc {
 	status = "okay";
 
 	port {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
 		ltdc_ep1_out: endpoint@1 {
 			reg = <1>;
 			remote-endpoint = <&dsi_in>;
diff --git a/arch/arm/boot/dts/stm32mp157c-ev1.dts b/arch/arm/boot/dts/stm32mp157c-ev1.dts
index ba8e9d9a42fa..49ca94c19b02 100644
--- a/arch/arm/boot/dts/stm32mp157c-ev1.dts
+++ b/arch/arm/boot/dts/stm32mp157c-ev1.dts
@@ -101,9 +101,14 @@ dcmi_0: endpoint {
 
 &dsi {
 	phy-dsi-supply = <&reg18>;
+	#address-cells = <1>;
+	#size-cells = <0>;
 	status = "okay";
 
 	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
 		port@0 {
 			reg = <0>;
 			dsi_in: endpoint {
@@ -119,7 +124,7 @@ dsi_out: endpoint {
 		};
 	};
 
-	panel-dsi@0 {
+	panel@0 {
 		compatible = "raydium,rm68200";
 		reg = <0>;
 		reset-gpios = <&gpiof 15 GPIO_ACTIVE_LOW>;
@@ -239,8 +244,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&dsi_in>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts b/arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts
index 407ed3952f75..eada9cf257be 100644
--- a/arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts
+++ b/arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts
@@ -161,8 +161,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&panel_input>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi
index 302efac5d26f..e1306f92fd82 100644
--- a/arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi
+++ b/arch/arm/boot/dts/stm32mp15xx-dhcor-avenger96.dtsi
@@ -336,11 +336,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		#address-cells = <1>;
-		#size-cells = <0>;
-
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&adv7513_in>;
 		};
 	};
diff --git a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
index 0f1110e42c93..a6e2e20f12fa 100644
--- a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
+++ b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
@@ -457,8 +457,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_ep0_out: endpoint@0 {
-			reg = <0>;
+		ltdc_ep0_out: endpoint {
 			remote-endpoint = <&sii9022_in>;
 		};
 	};
-- 
2.25.1

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Marek Vasut]

On 5/17/23 16:35, Raphael Gallais-Pou wrote:

Hi,

> diff --git a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
> index 0f1110e42c93..a6e2e20f12fa 100644
> --- a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
> +++ b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
> @@ -457,8 +457,7 @@ &ltdc {
>   	status = "okay";
>   
>   	port {
> -		ltdc_ep0_out: endpoint@0 {
> -			reg = <0>;
> +		ltdc_ep0_out: endpoint {
>   			remote-endpoint = <&sii9022_in>;
>   		};
>   	};

This LTDC port/endpoint stuff always scares me, because I always feel I 
get it wrong.

I believe the LTDC does have one "port" , correct.

But I think (?) that the LTDC has two endpoints, endpoint@0 for DPI 
(parallel output out of the SoC) and endpoint@1 for DSI (internal 
connection into the DSI serializer) ?

Only one of the endpoints can be connected at a time, but there are 
actually two endpoints in the LTDC port {} node, aren't there ?

So the original description should be OK I think , maybe 
#address/#size-cells are missing instead ?

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Raphael Gallais-Pou]

Hi Marek

On 5/17/23 17:41, Marek Vasut wrote:
> On 5/17/23 16:35, Raphael Gallais-Pou wrote:
>
> Hi,
>
>> diff --git a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>> b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>> index 0f1110e42c93..a6e2e20f12fa 100644
>> --- a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>> +++ b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>> @@ -457,8 +457,7 @@ &ltdc {
>>       status = "okay";
>>         port {
>> -        ltdc_ep0_out: endpoint@0 {
>> -            reg = <0>;
>> +        ltdc_ep0_out: endpoint {
>>               remote-endpoint = <&sii9022_in>;
>>           };
>>       };
>
> This LTDC port/endpoint stuff always scares me, because I always feel I get it
> wrong.
>
> I believe the LTDC does have one "port" , correct.
>
> But I think (?) that the LTDC has two endpoints, endpoint@0 for DPI (parallel
> output out of the SoC) and endpoint@1 for DSI (internal connection into the
> DSI serializer) ?

You are correct indeed, I rushed the patch and did not thought about this. I
agree that this can be confusing, as I also take some time to think through it.

>
> Only one of the endpoints can be connected at a time, but there are actually
> two endpoints in the LTDC port {} node, aren't there ?
Yes, they are mutually exclusive.
>
> So the original description should be OK I think , maybe #address/#size-cells
> are missing instead ?

Thing is: this file is only included in two device-trees : stm32mp157c-dk1.dts
and stm32mp157c-dk2.dts.

Among those two files there is only one which adds a second endpoint. Thus if
the fields are set higher in the hierarchy, a warning yields.

One way to do it would be to make the endpoint@0 go down in the device-tree with
its dependencies, so that both endpoints are the same level without generating
noise.


Raphaël

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Marek Vasut]

On 5/17/23 19:04, Raphael Gallais-Pou wrote:
> Hi Marek

Hi,

> On 5/17/23 17:41, Marek Vasut wrote:
>> On 5/17/23 16:35, Raphael Gallais-Pou wrote:
>>
>> Hi,
>>
>>> diff --git a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>> b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>> index 0f1110e42c93..a6e2e20f12fa 100644
>>> --- a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>> +++ b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>> @@ -457,8 +457,7 @@ &ltdc {
>>>        status = "okay";
>>>          port {
>>> -        ltdc_ep0_out: endpoint@0 {
>>> -            reg = <0>;
>>> +        ltdc_ep0_out: endpoint {
>>>                remote-endpoint = <&sii9022_in>;
>>>            };
>>>        };
>>
>> This LTDC port/endpoint stuff always scares me, because I always feel I get it
>> wrong.
>>
>> I believe the LTDC does have one "port" , correct.
>>
>> But I think (?) that the LTDC has two endpoints, endpoint@0 for DPI (parallel
>> output out of the SoC) and endpoint@1 for DSI (internal connection into the
>> DSI serializer) ?
> 
> You are correct indeed, I rushed the patch and did not thought about this. I
> agree that this can be confusing, as I also take some time to think through it.
> 
>>
>> Only one of the endpoints can be connected at a time, but there are actually
>> two endpoints in the LTDC port {} node, aren't there ?
> Yes, they are mutually exclusive.
>>
>> So the original description should be OK I think , maybe #address/#size-cells
>> are missing instead ?
> 
> Thing is: this file is only included in two device-trees : stm32mp157c-dk1.dts
> and stm32mp157c-dk2.dts.
> 
> Among those two files there is only one which adds a second endpoint. Thus if
> the fields are set higher in the hierarchy, a warning yields.

I do not understand this one part, which warning are you trying to fix ?
I just ran '$ make CHECK_DTBS=1 stm32mp157a-dk1.dtb stm32mp157c-dk2.dtb' 
in latest linux-next and there was no warning related to LTDC .

I think if you retain the stm32mp151.dtsi &ltdc { port { #address-cells 
= <1>; #size-cells = <0>; }; }; part, then you wouldn't be getting any 
warnings regarding LTDC , and you wouldn't have to remove the 
unit-address from endpoint@0 .

btw. I do use both endpoint@0/endpoint@1 in Avenger96 DTOs, but those 
are not submitted yet, I have to clean them up a bit more first.

> One way to do it would be to make the endpoint@0 go down in the device-tree with
> its dependencies, so that both endpoints are the same level without generating
> noise.

I'm afraid I really don't quite understand which warning you're 
referring to. Can you please share that warning and ideally how to 
trigger it (the command-line incantation) ?

-- 
Best regards,
Marek Vasut

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Raphael Gallais-Pou]

On 5/18/23 01:33, Marek Vasut wrote:
> On 5/17/23 19:04, Raphael Gallais-Pou wrote:
>> Hi Marek
>
> Hi,
>
>> On 5/17/23 17:41, Marek Vasut wrote:
>>> On 5/17/23 16:35, Raphael Gallais-Pou wrote:
>>>
>>> Hi,
>>>
>>>> diff --git a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>>> b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>>> index 0f1110e42c93..a6e2e20f12fa 100644
>>>> --- a/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>>> +++ b/arch/arm/boot/dts/stm32mp15xx-dkx.dtsi
>>>> @@ -457,8 +457,7 @@ &ltdc {
>>>>        status = "okay";
>>>>          port {
>>>> -        ltdc_ep0_out: endpoint@0 {
>>>> -            reg = <0>;
>>>> +        ltdc_ep0_out: endpoint {
>>>>                remote-endpoint = <&sii9022_in>;
>>>>            };
>>>>        };
>>>
>>> This LTDC port/endpoint stuff always scares me, because I always feel I get it
>>> wrong.
>>>
>>> I believe the LTDC does have one "port" , correct.
>>>
>>> But I think (?) that the LTDC has two endpoints, endpoint@0 for DPI (parallel
>>> output out of the SoC) and endpoint@1 for DSI (internal connection into the
>>> DSI serializer) ?
>>
>> You are correct indeed, I rushed the patch and did not thought about this. I
>> agree that this can be confusing, as I also take some time to think through it.
>>
>>>
>>> Only one of the endpoints can be connected at a time, but there are actually
>>> two endpoints in the LTDC port {} node, aren't there ?
>> Yes, they are mutually exclusive.
>>>
>>> So the original description should be OK I think , maybe #address/#size-cells
>>> are missing instead ?
>>
>> Thing is: this file is only included in two device-trees : stm32mp157c-dk1.dts
>> and stm32mp157c-dk2.dts.
>>
>> Among those two files there is only one which adds a second endpoint. Thus if
>> the fields are set higher in the hierarchy, a warning yields.
>
> I do not understand this one part, which warning are you trying to fix ?
> I just ran '$ make CHECK_DTBS=1 stm32mp157a-dk1.dtb stm32mp157c-dk2.dtb' in
> latest linux-next and there was no warning related to LTDC .

I'm sorry, I looked back at it and my explanations are confusing.

I use Alex Torgue's tree, and I'm based on the next branch, but linux-next
should be the same I just checked it.

>
> I think if you retain the stm32mp151.dtsi &ltdc { port { #address-cells = <1>;
> #size-cells = <0>; }; }; part, then you wouldn't be getting any warnings
> regarding LTDC , and you wouldn't have to remove the unit-address from
> endpoint@0 .
>
> btw. I do use both endpoint@0/endpoint@1 in Avenger96 DTOs, but those are not
> submitted yet, I have to clean them up a bit more first.
>
>> One way to do it would be to make the endpoint@0 go down in the device-tree with
>> its dependencies, so that both endpoints are the same level without generating
>> noise.
>
> I'm afraid I really don't quite understand which warning you're referring to.
> Can you please share that warning and ideally how to trigger it (the
> command-line incantation) ?

Using '$ make dtbs W=1', you can observe several of the followings:

arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning
(avoid_unnecessary_addr_size): /soc/display-controller@5a001000/port:
unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning (graph_child_address):
/soc/display-controller@5a001000/port: graph node has single child node
'endpoint@0', #address-cells/#size-cells are not necessary

This &ltdc { port { #address-cells = <1>; #size-cells = <0>; }; }; part is
actually annoying. This is because there is several device-trees that only got
one endpoint, and some other that includes two.

For instance: stm32mp15xx-dhcor-avenger96.dtsi vs stm32mp157c-dk2.dts.

I would like to remove to root part of address/size field and let only the lower
device-trees with with multiple endpoints handle their own fields. I hope this
explains a bit better my process.

Regards,
Raphaël Gallais-Pou

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Marek Vasut]

On 5/25/23 10:14, Raphael Gallais-Pou wrote:

Hi,

>> I think if you retain the stm32mp151.dtsi &ltdc { port { #address-cells = <1>;
>> #size-cells = <0>; }; }; part, then you wouldn't be getting any warnings
>> regarding LTDC , and you wouldn't have to remove the unit-address from
>> endpoint@0 .
>>
>> btw. I do use both endpoint@0/endpoint@1 in Avenger96 DTOs, but those are not
>> submitted yet, I have to clean them up a bit more first.
>>
>>> One way to do it would be to make the endpoint@0 go down in the device-tree with
>>> its dependencies, so that both endpoints are the same level without generating
>>> noise.
>>
>> I'm afraid I really don't quite understand which warning you're referring to.
>> Can you please share that warning and ideally how to trigger it (the
>> command-line incantation) ?
> 
> Using '$ make dtbs W=1', you can observe several of the followings:
> 
> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning
> (avoid_unnecessary_addr_size): /soc/display-controller@5a001000/port:
> unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning (graph_child_address):
> /soc/display-controller@5a001000/port: graph node has single child node
> 'endpoint@0', #address-cells/#size-cells are not necessary
> 
> This &ltdc { port { #address-cells = <1>; #size-cells = <0>; }; }; part is
> actually annoying. This is because there is several device-trees that only got
> one endpoint, and some other that includes two.
> 
> For instance: stm32mp15xx-dhcor-avenger96.dtsi vs stm32mp157c-dk2.dts.
> 
> I would like to remove to root part of address/size field and let only the lower
> device-trees with with multiple endpoints handle their own fields. I hope this
> explains a bit better my process.

After thinking about this some more, and digging through LTDC driver, 
and testing on EV1, I think dropping the LTDC node endpoint@N and 
reg=<N> altogether and just using port/endpoint (singular) is fine.

You might want to split the DSI node specific changes and the LTDC node 
specific changes into separate patches (LTDC specific change like you 
did in 1/3).

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Raphael Gallais-Pou]

On 5/26/23 18:55, Marek Vasut wrote:
> On 5/25/23 10:14, Raphael Gallais-Pou wrote:
>
> Hi,
Hi Marek,
>
>>> I think if you retain the stm32mp151.dtsi &ltdc { port { #address-cells = <1>;
>>> #size-cells = <0>; }; }; part, then you wouldn't be getting any warnings
>>> regarding LTDC , and you wouldn't have to remove the unit-address from
>>> endpoint@0 .
>>>
>>> btw. I do use both endpoint@0/endpoint@1 in Avenger96 DTOs, but those are not
>>> submitted yet, I have to clean them up a bit more first.
>>>
>>>> One way to do it would be to make the endpoint@0 go down in the device-tree
>>>> with
>>>> its dependencies, so that both endpoints are the same level without generating
>>>> noise.
>>>
>>> I'm afraid I really don't quite understand which warning you're referring to.
>>> Can you please share that warning and ideally how to trigger it (the
>>> command-line incantation) ?
>>
>> Using '$ make dtbs W=1', you can observe several of the followings:
>>
>> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning
>> (avoid_unnecessary_addr_size): /soc/display-controller@5a001000/port:
>> unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
>> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning (graph_child_address):
>> /soc/display-controller@5a001000/port: graph node has single child node
>> 'endpoint@0', #address-cells/#size-cells are not necessary
>>
>> This &ltdc { port { #address-cells = <1>; #size-cells = <0>; }; }; part is
>> actually annoying. This is because there is several device-trees that only got
>> one endpoint, and some other that includes two.
>>
>> For instance: stm32mp15xx-dhcor-avenger96.dtsi vs stm32mp157c-dk2.dts.
>>
>> I would like to remove to root part of address/size field and let only the lower
>> device-trees with with multiple endpoints handle their own fields. I hope this
>> explains a bit better my process.
>
> After thinking about this some more, and digging through LTDC driver, and
> testing on EV1, I think dropping the LTDC node endpoint@N and reg=<N>
> altogether and just using port/endpoint (singular) is fine.
>
> You might want to split the DSI node specific changes and the LTDC node
> specific changes into separate patches (LTDC specific change like you did in
> 1/3).

Yes, I prepared a new serie with that split, to that it is better to read and
review.


Raphaël

Re: [PATCH v3 3/3] ARM: dts: stm32: fix several DT warnings on stm32mp15

[Marek Vasut]

On 5/29/23 10:07, Raphael Gallais-Pou wrote:

Hi,

>>>> I think if you retain the stm32mp151.dtsi &ltdc { port { #address-cells = <1>;
>>>> #size-cells = <0>; }; }; part, then you wouldn't be getting any warnings
>>>> regarding LTDC , and you wouldn't have to remove the unit-address from
>>>> endpoint@0 .
>>>>
>>>> btw. I do use both endpoint@0/endpoint@1 in Avenger96 DTOs, but those are not
>>>> submitted yet, I have to clean them up a bit more first.
>>>>
>>>>> One way to do it would be to make the endpoint@0 go down in the device-tree
>>>>> with
>>>>> its dependencies, so that both endpoints are the same level without generating
>>>>> noise.
>>>>
>>>> I'm afraid I really don't quite understand which warning you're referring to.
>>>> Can you please share that warning and ideally how to trigger it (the
>>>> command-line incantation) ?
>>>
>>> Using '$ make dtbs W=1', you can observe several of the followings:
>>>
>>> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning
>>> (avoid_unnecessary_addr_size): /soc/display-controller@5a001000/port:
>>> unnecessary #address-cells/#size-cells without "ranges" or child "reg" property
>>> arch/arm/boot/dts/stm32mp151.dtsi:1533.9-1536.6: Warning (graph_child_address):
>>> /soc/display-controller@5a001000/port: graph node has single child node
>>> 'endpoint@0', #address-cells/#size-cells are not necessary
>>>
>>> This &ltdc { port { #address-cells = <1>; #size-cells = <0>; }; }; part is
>>> actually annoying. This is because there is several device-trees that only got
>>> one endpoint, and some other that includes two.
>>>
>>> For instance: stm32mp15xx-dhcor-avenger96.dtsi vs stm32mp157c-dk2.dts.
>>>
>>> I would like to remove to root part of address/size field and let only the lower
>>> device-trees with with multiple endpoints handle their own fields. I hope this
>>> explains a bit better my process.
>>
>> After thinking about this some more, and digging through LTDC driver, and
>> testing on EV1, I think dropping the LTDC node endpoint@N and reg=<N>
>> altogether and just using port/endpoint (singular) is fine.
>>
>> You might want to split the DSI node specific changes and the LTDC node
>> specific changes into separate patches (LTDC specific change like you did in
>> 1/3).
> 
> Yes, I prepared a new serie with that split, to that it is better to read and
> review.

Thank you !