Thread (9 messages) 9 messages, 2 authors, 2020-03-23

Re: [PATCH v2 1/6] dt-bindings: dma: uniphier-xdmac: Remove extension register region description

From: Masahiro Yamada <masahiroy@kernel.org>
Date: 2020-03-19 14:19:37
Also in: linux-devicetree

On Thu, Mar 19, 2020 at 4:51 PM Kunihiko Hayashi
[off-list ref] wrote:
The address of the extension register region in example is incorrect,
however, this extension register region is optional

On which SoC is it optional?

In your previous DT submission, every reg was,
like this:

reg = <0x5fc10000 0x1000>, <0x5fc20000 0x800>;



and you meant

reg = <0x5fc10000 0x1000>, <0x5fc12000 0x800>;

?
and isn't currently
referred from the driver, so the description of the region should be
suppressed until referred by the driver.
This sounds like you plan to get it back
as you extend the driver.

I checked the datasheet. This controller has more registers,
so you split the reg into small chunks, the final form will look scary:

reg = <0x5fc10000 0x1000>, <0x5fc12000 0x800>,
      <0x5fc14000 0x100>,  <0x5fc15000 0x100>;


My question is why you did not use a single reg tuple
that covers the whole registers.

Is any other hardware reg interleaved in between?





quoted hunk ↗ jump to hunk
Fixes: b9fb56b6ba8a ("dt-bindings: dmaengine: Add UniPhier external DMA controller bindings")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
 Documentation/devicetree/bindings/dma/socionext,uniphier-xdmac.yaml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/socionext,uniphier-xdmac.yaml b/Documentation/devicetree/bindings/dma/socionext,uniphier-xdmac.yaml
index 86cfb59..f4c3f49 100644
--- a/Documentation/devicetree/bindings/dma/socionext,uniphier-xdmac.yaml
+++ b/Documentation/devicetree/bindings/dma/socionext,uniphier-xdmac.yaml
@@ -24,7 +24,6 @@ properties:
   reg:
     items:
       - description: XDMAC base register region (offset and length)
-      - description: XDMAC extension register region (offset and length)

   interrupts:
     maxItems: 1
@@ -54,7 +53,7 @@ examples:
   - |
     xdmac: dma-controller@5fc10000 {
         compatible = "socionext,uniphier-xdmac";
-        reg = <0x5fc10000 0x1000>, <0x5fc20000 0x800>;
+        reg = <0x5fc10000 0x1000>;
         interrupts = <0 188 4>;
         #dma-cells = <2>;
         dma-channels = <16>;
--
2.7.4

-- 
Best Regards
Masahiro Yamada

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