Subject: RE: [PATCH v20 1/4] dt-bindings: i2c: Split AST2600 binding into a new
YAML

quoted

Subject: Re: [PATCH v20 1/4] dt-bindings: i2c: Split AST2600 binding
into a new YAML

On 29/10/2025 09:29, Ryan Chen wrote:

quoted

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Subject: Re: [PATCH v20 1/4] dt-bindings: i2c: Split AST2600
binding into a new YAML

On 21/10/2025 03:35, Ryan Chen wrote:

quoted

The AST2600 I2C controller is a new hardware design compared to
the I2C controllers in previous ASPEED SoCs (e.g., AST2400, AST2500).

It introduces new features such as:
 - A redesigned register layout
 - Separation between controller and target mode registers
 - Transfer mode selection (byte, buffer, DMA)
 - Support for a shared global register block for configuration

Due to these fundamental differences, maintaining a separate
devicetree binding file for AST2600 helps to clearly distinguish
the hardware capabilities and configuration options from the older
controllers.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
 .../devicetree/bindings/i2c/aspeed,i2c.yaml   |  3 +-
 .../devicetree/bindings/i2c/ast2600-i2c.yaml  | 66
+++++++++++++++++++
 2 files changed, 67 insertions(+), 2 deletions(-)  create mode
100644 Documentation/devicetree/bindings/i2c/ast2600-i2c.yaml

diff --git a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml

b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
index 5b9bd2feda3b..d4e4f412feba 100644

--- a/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml

@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/i2c/aspeed,i2c.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#

-title: ASPEED I2C on the AST24XX, AST25XX, and AST26XX SoCs
+title: ASPEED I2C on the AST24XX, AST25XX SoCs

 maintainers:
   - Rayn Chen <rayn_chen@aspeedtech.com> @@ -17,7 +17,6 @@

properties:
     enum:
       - aspeed,ast2400-i2c-bus
       - aspeed,ast2500-i2c-bus
-      - aspeed,ast2600-i2c-bus

   reg:
     minItems: 1
diff --git
a/Documentation/devicetree/bindings/i2c/ast2600-i2c.yaml
b/Documentation/devicetree/bindings/i2c/ast2600-i2c.yaml

Why completely breaking naming? Please follow writing bindings

carefully.

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Will update
$id: "http://devicetree.org/schemas/i2c/aspeed,ast2600-i2c.yaml#"

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new file mode 100644
index 000000000000..6ddcec5decdc

--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/ast2600-i2c.yaml

@@ -0,0 +1,66 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML
+1.2
+---
+$id: http://devicetree.org/schemas/i2c/ast2600-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED I2C on the AST26XX SoCs
+
+maintainers:
+  - Ryan Chen <ryan_chen@aspeedtech.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2600-i2c-bus
+
+  reg:
+    minItems: 1

Why?

Will update as following.

reg:
  minItems: 1
  maxItems: 2

No. You changed nothing. Instead explain why this is flexible.

See writing bindings.

Sorry, I still not understand your point. Do you mean need to explain why reg is
flexible 1 -> 2?
If yes, I will update to following.

reg:
  minItems: 1
  maxItems: 2
  description:
    The first region covers the controller registers.
    The optional second region covers the controller's buffer space.

After check the
https://docs.kernel.org/devicetree/bindings/writing-schema.html#annotated-example-schema
I think I should update with following, am I correct ?

 reg:
   items:
     - description: The first region covers the controller registers.
	 - description: The optional second region covers the controller's buffer space.

What you question about 
" Please explain me how one, same SoC has optional IO address space? I asked to explain WHY this is flexible"
The AST2600 i2c controller have three io,buffer,dma mode. 
The AST2600 have buffer register for buffer transfer. That is 2nd reg offset. 
If dtsi not descript it, the driver will go back to io mode transfer. Flexible implement is in driver.

"

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...

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+  bus-frequency:
+    minimum: 500
+    maximum: 4000000
+    default: 100000
+    description: frequency of the bus clock in Hz defaults to 100
+ kHz when

not

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+      specified

Don't repeat constraints in free form text.

Will update
clock-frequency:
    description: Desired I2C bus frequency in Hz
    default: 100000

Heh? You are making random set of changes like did not really read the
feedback. I not to repeat something. What is repeated? Constraints.
Where are the repeated "in free form text". What did you do? Dropped
constraints.

Sorry, I misunderstood your comment,
I think you are point out my description.

I will update with following.

clock-frequency:
  description: Desired operating frequency of the I2C bus in Hz.
  minimum: 500
  maximum: 4000000
  default: 100000

quoted

I don't know what to say.

Best regards,
Krzysztof