Re: [EXT] Re: [PATCH 2/2] dt-bindings: i2c: imx-lpi2c: Add bus recovery example

Resending as my previous email probably got lost. If you got it twice,
apologies.

On 31/05/2023 12:22, Carlos Song wrote:

Hi,
	Thanks for you reply. 

quoted

-----Original Message-----
From: Krzysztof Kozlowski <redacted>
Sent: Tuesday, May 30, 2023 10:59 PM
To: Carlos Song <redacted>; Aisheng Dong
[off-list ref]; shawnguo@kernel.org; s.hauer@pengutronix.de;
kernel@pengutronix.de; festevam@gmail.com; robh+dt@kernel.org;
krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org;
Anson.Huang@nxp.com
Cc: Clark Wang <xiaoning.wang@nxp.com>; Bough Chen
[off-list ref]; dl-linux-imx [off-list ref];
linux-i2c@vger.kernel.org; devicetree@vger.kernel.org;
linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
Subject: [EXT] Re: [PATCH 2/2] dt-bindings: i2c: imx-lpi2c: Add bus recovery
example

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On 29/05/2023 09:43, carlos.song@nxp.com wrote:

quoted

From: Clark Wang <xiaoning.wang@nxp.com>

Add i2c bus recovery configuration example.

Why? That's just example... also with coding style issue.

quoted

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Carlos Song <redacted>
---
 .../devicetree/bindings/i2c/i2c-imx-lpi2c.yaml   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml

b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml
index 4656f5112b84..62ee457496e4 100644

--- a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml

@@ -58,6 +58,16 @@ properties:
   power-domains:
     maxItems: 1

+  pinctrl-names:
+    minItems: 1
+    maxItems: 3

What's the benefit of this? Entries should be defined but without it is not really
helpful. Anyway not explained in commit msg.

quoted

+
+  scl-gpios:
+    maxItems: 1
+
+  sda-gpios:
+    maxItems: 1

You don't need these two. Anyway not explained in commit msg.

Sorry for confusing you with the poor commit log and without
full description.

The reason why we need sending the patch for dt-binding is :
We sent out a patch for I.MX LPI2C bus support recovery function.
When LPI2C use recovery function, lpi2c controller need to switch the 
SCL pin and SDA pin to their GPIO function.  So I think the scl-gpio and
sda-gpio property need to be added in the dt-bindings.

Why do you think they are not in the bindings already?

And alternative pinmux settings are described in a separate pinctrl state "gpio". 
So maybe "gpio" pinctrl item need to be added.

I would like to know whether the above changes are really unnecessary according to above case?
Or because of the vague commit log, you are misled and think that our patch is not necessary to add examples.

I claim your patch has zero effect. Can you prove otherwise?

Proof is with DTS example and result of dtbs_check.

Is there no need to add sda/scl-gpios property or no need to add maxItems: 1?

I think entire patch can be dropped.

We also find the sci-gpio and sda-gpio have been defined in the ref: /schemas/i2c/i2c-controller.yaml. 
So is this the root cause of no need to add these properties?

Yes.


Best regards,
Krzysztof


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