On 21 August 2018 at 15:17, Masahiro Yamada
[off-list ref] wrote:

(+CC Rob, DT, LKML)

I forgot to CC this to DT community...


2018-08-21 18:30 GMT+09:00 Masahiro Yamada [off-list ref]:

quoted

The MIO DMAC (Media IO DMA Controller) is used in UniPhier LD4,
Pro4, and sLD8 SoCs.

Signed-off-by: Masahiro Yamada <redacted>
---

 .../devicetree/bindings/dma/uniphier-mio-dmac.txt  | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt

diff --git a/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt
new file mode 100644
index 0000000..a9e969e
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/uniphier-mio-dmac.txt

@@ -0,0 +1,28 @@
+UniPhier Media IO DMA controller
+
+This works as an external DMA engine for SD/eMMC controllers etc.
+found in UniPhier LD4, Pro4, sLD8 SoCs.
+
+Required properties:
+- compatible: should be "socionext,uniphier-mio-dmac".
+- reg: offset and length of the register set for the device.
+- interrupts: a list of interrupt specifiers associated with the DMA channels.
+- clocks: a single clock specifier
+- #dma-cells: should be <1>. The single cell represents the channel number.
+- dma-channels: specify the number of the DMA channels. This should match to
+  the number of tuples in the interrupts property.
+

Can we not infer the number of channels from interrupt tuples? After
all the driver assumes they are same.