[PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties

Ryan Chen posted 4 patches 2 days, 23 hours ago
[PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
Posted by Ryan Chen 2 days, 23 hours ago
Add aspeed,enable-dma boolean property to indicate that DMA is
available for transfers on this I2C bus.

Also add the aspeed,global-regs phandle to reference the AST2600
global registers syscon node, containing the SoC-common I2C register
set.

These properties apply only to the AST2600 binding. Legacy DTs remain
unchanged.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v28:
- update commit message correspond with aspeed,enable-dma.
- remove aspeed,transfer-mode and add aspeed,enable-dma property and
  description.
- Fix aspeed,enable-dma description to reflect hardware capability rather
  than software behavior
Changes in v27:
- change aspeed,transfer-mode to aspeed,enable-dma.
---
 .../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml          | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
index de2c359037da..67b23d1a4cec 100644
--- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
@@ -37,6 +37,16 @@ properties:
   resets:
     maxItems: 1
 
+  aspeed,enable-dma:
+    type: boolean
+    description: Indicates this I2C controller instance has DMA capability.
+
+  aspeed,global-regs:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle reference to the i2c global syscon node, containing the
+      SoC-common i2c register set.
+
 required:
   - reg
   - compatible
@@ -59,4 +69,6 @@ examples:
         resets = <&syscon ASPEED_RESET_I2C>;
         clock-frequency = <100000>;
         interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+        aspeed,global-regs = <&i2c_global>;
+        aspeed,enable-dma;
     };

-- 
2.34.1
Re: [PATCH v28 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and enable-dma properties
Posted by Krzysztof Kozlowski 2 days ago
On Mon, Mar 30, 2026 at 04:21:47PM +0800, Ryan Chen wrote:
> Add aspeed,enable-dma boolean property to indicate that DMA is
> available for transfers on this I2C bus.
> 
> Also add the aspeed,global-regs phandle to reference the AST2600
> global registers syscon node, containing the SoC-common I2C register
> set.
> 
> These properties apply only to the AST2600 binding. Legacy DTs remain
> unchanged.
> 
> Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
> ---
> Changes in v28:
> - update commit message correspond with aspeed,enable-dma.
> - remove aspeed,transfer-mode and add aspeed,enable-dma property and
>   description.
> - Fix aspeed,enable-dma description to reflect hardware capability rather
>   than software behavior
> Changes in v27:
> - change aspeed,transfer-mode to aspeed,enable-dma.
> ---
>  .../devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml          | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> index de2c359037da..67b23d1a4cec 100644
> --- a/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/aspeed,ast2600-i2c.yaml
> @@ -37,6 +37,16 @@ properties:
>    resets:
>      maxItems: 1
>  
> +  aspeed,enable-dma:
> +    type: boolean
> +    description: Indicates this I2C controller instance has DMA capability.

Compatible implies that "I2C controller instance has DMA capability", no?

How two same devices, with exactly the same or compatible programming
model can have difference in the programming model for DMA (one lacks
it)?

Best regards,
Krzysztof