[PATCH v3 02/13] dt-bindings: memory: mediatek: Add mt8195 smi sub common

From: Yong Wu
Date: Tue Aug 10 2021 - 04:11:16 EST


Add the binding for smi-sub-common. The SMI block diagram like this:

IOMMU
| |
smi-common
------------------
| .... |
larb0 larb7 <-max is 8

The smi-common connects with smi-larb and IOMMU. The maximum larbs number
that connects with a smi-common is 8. If the engines number is over 8,
sometimes we use a smi-sub-common which is nearly same with smi-common.
It supports up to 8 input and 1 output(smi-common has 2 output)

Something like:

IOMMU
| |
smi-common
---------------------
| | ...
larb0 sub-common ... <-max is 8
-----------
| | ... <-max is 8 too.
larb2 larb5

We don't need extra SW setting for smi-sub-common, only the sub-common has
special clocks need to enable when the engines access dram.

If it is sub-common, it should have a "mediatek,smi" phandle to point to
its smi-common. meanwhile the sub-common only has one gals clock.

Additionally, add a new property "mediatek,smi_sub_common" for this
sub-common, this is needed in the IOMMU driver in which we create a device
link between smi-common and the IOMMU device. If we add the smi-sub-common
here, the IOMMU driver still need to find the smi-common device. thus,
add this bool property to indicate if it is sub-common.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
change note:
a. change mediatek, smi type from phandle-array to phandle from Rob.
b. Add a new bool property (mediatek,smi_sub_common) to indicate this is
smi-sub-common. the reason is as above.
---
.../mediatek,smi-common.yaml | 30 +++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml b/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
index 602592b6c3f5..26bb9903864b 100644
--- a/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,smi-common.yaml
@@ -38,6 +38,7 @@ properties:
- mediatek,mt8192-smi-common
- mediatek,mt8195-smi-common-vdo
- mediatek,mt8195-smi-common-vpp
+ - mediatek,mt8195-smi-sub-common

- description: for mt7623
items:
@@ -67,6 +68,14 @@ properties:
minItems: 2
maxItems: 4

+ mediatek,smi:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: a phandle to the smi-common node above. Only for sub-common.
+
+ mediatek,smi_sub_common:
+ type: boolean
+ description: Indicate if this is smi-sub-common.
+
required:
- compatible
- reg
@@ -93,6 +102,27 @@ allOf:
- const: smi
- const: async

+ - if: # only for sub common
+ properties:
+ compatible:
+ contains:
+ enum:
+ - mediatek,mt8195-smi-sub-common
+ then:
+ required:
+ - mediatek,smi
+ - mediatek,smi_sub_common
+ properties:
+ clock:
+ items:
+ minItems: 3
+ maxItems: 3
+ clock-names:
+ items:
+ - const: apb
+ - const: smi
+ - const: gals0
+
- if: # for gen2 HW that have gals
properties:
compatible:
--
2.18.0