[V4] dt-bindings: nvmem: fixed-cell: add compatible for MAC cells
Commit Message
From: Rafał Miłecki <rafal@milecki.pl>
A lot of home routers have NVMEM fixed cells containing MAC address that
need some further processing. In ~99% cases MAC needs to be:
1. Optionally parsed from ASCII format
2. Increased by a vendor-picked value
There was already an attempt to design a binding for that at NVMEM
device level in the past. It wasn't accepted though as it didn't really
fit NVMEM device layer.
The introduction of NVMEM fixed-cells layout seems to be an opportunity
to provide a relevant binding in a clean way.
This commit adds a *generic* compatible string: "mac-base". As always it
needs to be carefully reviewed.
OpenWrt project currently supports ~300 home routers that have NVMEM
cell with binary-stored base MAC.T hose devices are manufactured by
multiple vendors. There are TP-Link devices (76 of them), Netgear (19),
D-Link (11), OpenMesh (9), EnGenius (8), GL.iNet (8), ZTE (7),
Xiaomi (5), Ubiquiti (6) and more. Those devices don't share an
architecture or SoC.
Another 200 devices have base MAC stored in an ASCII format (not all
those devices have been converted to DT though).
It would be impractical to provide unique "compatible" strings for NVMEM
layouts of all those devices. It seems like a valid case for allowing a
generic binding instead. Even if this binding will not be sufficient for
some further devices it seems to be useful enough as it is.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
V2: Drop "mac-ascii" as length can be checked instead
Fix "allOf" by adding required: [ compatible ]
V3: Fix cell length in "description" (thank you Rob!)
V4: Fix cell length (12 → 6) in fixed-layout.yaml example as well
---
.../bindings/nvmem/layouts/fixed-cell.yaml | 26 +++++++++++++++++++
.../bindings/nvmem/layouts/fixed-layout.yaml | 12 +++++++++
.../devicetree/bindings/nvmem/nvmem.yaml | 5 +++-
3 files changed, 42 insertions(+), 1 deletion(-)
Comments
On Tue, 27 Jun 2023 22:46:30 +0200, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
>
> A lot of home routers have NVMEM fixed cells containing MAC address that
> need some further processing. In ~99% cases MAC needs to be:
> 1. Optionally parsed from ASCII format
> 2. Increased by a vendor-picked value
>
> There was already an attempt to design a binding for that at NVMEM
> device level in the past. It wasn't accepted though as it didn't really
> fit NVMEM device layer.
>
> The introduction of NVMEM fixed-cells layout seems to be an opportunity
> to provide a relevant binding in a clean way.
>
> This commit adds a *generic* compatible string: "mac-base". As always it
> needs to be carefully reviewed.
>
> OpenWrt project currently supports ~300 home routers that have NVMEM
> cell with binary-stored base MAC.T hose devices are manufactured by
> multiple vendors. There are TP-Link devices (76 of them), Netgear (19),
> D-Link (11), OpenMesh (9), EnGenius (8), GL.iNet (8), ZTE (7),
> Xiaomi (5), Ubiquiti (6) and more. Those devices don't share an
> architecture or SoC.
>
> Another 200 devices have base MAC stored in an ASCII format (not all
> those devices have been converted to DT though).
>
> It would be impractical to provide unique "compatible" strings for NVMEM
> layouts of all those devices. It seems like a valid case for allowing a
> generic binding instead. Even if this binding will not be sufficient for
> some further devices it seems to be useful enough as it is.
>
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
> V2: Drop "mac-ascii" as length can be checked instead
> Fix "allOf" by adding required: [ compatible ]
> V3: Fix cell length in "description" (thank you Rob!)
> V4: Fix cell length (12 → 6) in fixed-layout.yaml example as well
> ---
> .../bindings/nvmem/layouts/fixed-cell.yaml | 26 +++++++++++++++++++
> .../bindings/nvmem/layouts/fixed-layout.yaml | 12 +++++++++
> .../devicetree/bindings/nvmem/nvmem.yaml | 5 +++-
> 3 files changed, 42 insertions(+), 1 deletion(-)
>
Reviewed-by: Rob Herring <robh@kernel.org>
On Tue, 27 Jun 2023 22:46:30 +0200, Rafał Miłecki wrote:
> A lot of home routers have NVMEM fixed cells containing MAC address that
> need some further processing. In ~99% cases MAC needs to be:
> 1. Optionally parsed from ASCII format
> 2. Increased by a vendor-picked value
>
> There was already an attempt to design a binding for that at NVMEM
> device level in the past. It wasn't accepted though as it didn't really
> fit NVMEM device layer.
>
> [...]
Applied, thanks!
[1/1] dt-bindings: nvmem: fixed-cell: add compatible for MAC cells
commit: b7495ea1b534fa4d73e5132f05ecc79f5068aa22
Best regards,
@@ -11,6 +11,15 @@ maintainers:
- Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
properties:
+ compatible:
+ oneOf:
+ - const: mac-base
+ description: >
+ Cell with base MAC address to be used for calculating extra relative
+ addresses.
+ It can be stored in a plain binary format (cell length 6) or as an
+ ASCII text like "00:11:22:33:44:55" (cell length 17).
+
reg:
maxItems: 1
@@ -25,6 +34,23 @@ properties:
description:
Size in bit within the address range specified by reg.
+allOf:
+ - if:
+ required: [ compatible ]
+ then:
+ if:
+ properties:
+ compatible:
+ contains:
+ const: mac-base
+ then:
+ properties:
+ "#nvmem-cell-cells":
+ description: The first argument is a MAC address offset.
+ const: 1
+ required:
+ - "#nvmem-cell-cells"
+
required:
- reg
@@ -44,6 +44,18 @@ examples:
#address-cells = <1>;
#size-cells = <1>;
+ mac@100 {
+ compatible = "mac-base";
+ reg = <0x100 0x6>;
+ #nvmem-cell-cells = <1>;
+ };
+
+ mac@110 {
+ compatible = "mac-base";
+ reg = <0x110 0x11>;
+ #nvmem-cell-cells = <1>;
+ };
+
calibration@4000 {
reg = <0x4000 0x100>;
};
@@ -49,7 +49,10 @@ properties:
patternProperties:
"@[0-9a-f]+(,[0-7])?$":
type: object
- $ref: layouts/fixed-cell.yaml
+ allOf:
+ - $ref: layouts/fixed-cell.yaml
+ - properties:
+ compatible: false
deprecated: true
additionalProperties: true