diff mbox series

[v1,07/14] dt-bindings: lcdif: Do not require power-domains for i.MX6ULL

Message ID 20240210012114.489102-8-sre@kernel.org
State New
Headers
Series UNI-T UTi260B support |

Commit Message

Sebastian Reichel Feb. 10, 2024, 1:18 a.m. UTC 
  i.MX6UL(L) uses "fsl,imx6sx-lcdif" as fallback compatible string,
but has only very lightweight DISPLAY power domain. Its DISPLAY
power domain is not supported by the binding / Linux kernel at
the moment. Since the current setup is working, let's remove the
power-domain from being required for that platform to fix the warning
printed by CHECK_DTBS=y.

Fixes: f62678a77d58 ("dt-bindings: mxsfb: Document i.MX8M/i.MX6SX/i.MX6SL power-domains property")
Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 Documentation/devicetree/bindings/display/fsl,lcdif.yaml | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Krzysztof Kozlowski Feb. 11, 2024, 12:48 p.m. UTC | #1 
On 10/02/2024 02:18, Sebastian Reichel wrote:
> i.MX6UL(L) uses "fsl,imx6sx-lcdif" as fallback compatible string,
> but has only very lightweight DISPLAY power domain. Its DISPLAY
> power domain is not supported by the binding / Linux kernel at
> the moment. Since the current setup is working, let's remove 


Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>


Best regards,
Krzysztof
Stefan Wahren Feb. 12, 2024, 7:20 p.m. UTC | #2 
Hi Sebastian,

Am 10.02.24 um 02:18 schrieb Sebastian Reichel:
> i.MX6UL(L) uses "fsl,imx6sx-lcdif" as fallback compatible string,
> but has only very lightweight DISPLAY power domain. Its DISPLAY
> power domain is not supported by the binding / Linux kernel at
> the moment. Since the current setup is working, let's remove the
> power-domain from being required for that platform to fix the warning
> printed by CHECK_DTBS=y.
i'm not sure this is a good idea. In case i.MX6UL(L) is different from
i.MX6SX here, then it should have a different compatible.

Regards
Sebastian Reichel Feb. 12, 2024, 11:10 p.m. UTC | #3 
Hi Stefan,

On Mon, Feb 12, 2024 at 08:20:35PM +0100, Stefan Wahren wrote:
> Am 10.02.24 um 02:18 schrieb Sebastian Reichel:
> > i.MX6UL(L) uses "fsl,imx6sx-lcdif" as fallback compatible string,
> > but has only very lightweight DISPLAY power domain. Its DISPLAY
> > power domain is not supported by the binding / Linux kernel at
> > the moment. Since the current setup is working, let's remove the
> > power-domain from being required for that platform to fix the warning
> > printed by CHECK_DTBS=y.
> i'm not sure this is a good idea. In case i.MX6UL(L) is different from
> i.MX6SX here, then it should have a different compatible.

It already has. The i.MX6UL(L) compatible looks like this:

compatible = "fsl,imx6ul-lcdif", "fsl,imx6sx-lcdif"

So the i.MX6SX one is just a fallback compatible. But the current
requirement for power-domains affects i.MX6UL(L), since it says
the compatible only needs to contain "fsl,imx6sx-lcdif" somewhere
to make power-domains mandatory.

Note, that the kernel driver does not use "fsl,imx6ul-lcdif", so
the hardware itself is indeed compatible.

-- Sebastian
Stefan Wahren Feb. 13, 2024, 8:57 a.m. UTC | #4 
Hi Sebastian,

Am 13.02.24 um 00:10 schrieb Sebastian Reichel:
> Hi Stefan,
>
> On Mon, Feb 12, 2024 at 08:20:35PM +0100, Stefan Wahren wrote:
>> Am 10.02.24 um 02:18 schrieb Sebastian Reichel:
>>> i.MX6UL(L) uses "fsl,imx6sx-lcdif" as fallback compatible string,
>>> but has only very lightweight DISPLAY power domain. Its DISPLAY
>>> power domain is not supported by the binding / Linux kernel at
>>> the moment. Since the current setup is working, let's remove the
>>> power-domain from being required for that platform to fix the warning
>>> printed by CHECK_DTBS=y.
>> i'm not sure this is a good idea. In case i.MX6UL(L) is different from
>> i.MX6SX here, then it should have a different compatible.
> It already has. The i.MX6UL(L) compatible looks like this:
>
> compatible = "fsl,imx6ul-lcdif", "fsl,imx6sx-lcdif"
>
> So the i.MX6SX one is just a fallback compatible. But the current
> requirement for power-domains affects i.MX6UL(L), since it says
> the compatible only needs to contain "fsl,imx6sx-lcdif" somewhere
> to make power-domains mandatory.
thanks, i misunderstood the commit message. I thought this was a
i.MX6UL(L) specific issue and the i.MX6SX is slightly different. In the
past the fallback compatible was sometimes abused.

So everything makes sense now.
> Note, that the kernel driver does not use "fsl,imx6ul-lcdif", so
> the hardware itself is indeed compatible.
>
> -- Sebastian
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
index 1c2be8d6f633..0681fc49aa1b 100644
--- a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
+++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
@@ -120,13 +120,19 @@  allOf:
           maxItems: 1
         clock-names:
           maxItems: 1
+  - if:
+      properties:
+        compatible:
+          const: fsl,imx6sx-lcdif
+    then:
+      required:
+        - power-domains
   - if:
       properties:
         compatible:
           contains:
             enum:
               - fsl,imx6sl-lcdif
-              - fsl,imx6sx-lcdif
               - fsl,imx8mm-lcdif
               - fsl,imx8mn-lcdif
               - fsl,imx8mp-lcdif