[PATCH v3 net-next 00/10] dt-binding preparation for ocelot switches

Colin Foster
2022-11-27T22:48:01Z

Ocelot switches have the abilitiy to be used internally via
memory-mapped IO or externally via SPI or PCIe. This brings up issues
for documentation, where the same chip might be accessed internally in a
switchdev manner, or externally in a DSA configuration. This patch set
is perparation to bring DSA functionality to the VSC7512, utilizing as
much as possible with an almost identical VSC7514 chip.

This patch set changed quite a bit from v2, so I'll omit the background
of how those sets came to be. Rob offered a lot of very useful guidance.
My thanks.

At the end of the day, with this patch set, there should be a framework
to document Ocelot switches (and any switch) in scenarios where they can
be controlled internally (ethernet-switch) or externally (dsa-switch).

---

v2 -> v3
* Restructured everything to use a "base" iref for devices that don't
have additional properties, and simply a "ref" for devices that do.
* New patches to fix up brcm,sf2, qca8k, and mt7530
* Fix unevaluatedProperties errors from previous sets (see specific
patches for more detail)
* Removed redundant "Device Tree Binding" from titles, where applicable.

v1 -> v2
* Two MFD patches were brought into the MFD tree, so are dropped
* Add first patch 1/6 to allow DSA devices to add ports and port
properties
* Test qca8k against new dt-bindings and fix warnings. (patch 2/6)
* Add tags (patch 3/6)
* Fix vsc7514 refs and properties

---

Colin Foster (10):
dt-bindings: net: dsa: sf2: fix brcm,use-bcm-hdr documentation
dt-bindings: net: dsa: qca8k: remove address-cells and size-cells from
switch node
dt-bindings: net: dsa: utilize base definitions for standard dsa
switches
dt-bindings: net: dsa: allow additional ethernet-port properties
dt-bindings: net: dsa: qca8k: utilize shared dsa.yaml
dt-bindings: net: dsa: mediatek,mt7530: fix port description location
dt-bindings: net: dsa: mediatek,mt7530: remove unnecessary dsa-port
reference
dt-bindings: net: add generic ethernet-switch
dt-bindings: net: add generic ethernet-switch-port binding
dt-bindings: net: mscc,vsc7514-switch: utilize generic
ethernet-switch.yaml

.../bindings/net/dsa/arrow,xrs700x.yaml | 2 +-
.../devicetree/bindings/net/dsa/brcm,b53.yaml | 2 +-
.../devicetree/bindings/net/dsa/brcm,sf2.yaml | 15 +++--
.../devicetree/bindings/net/dsa/dsa-port.yaml | 24 +------
.../devicetree/bindings/net/dsa/dsa.yaml | 37 +++++------
.../net/dsa/hirschmann,hellcreek.yaml | 2 +-
.../bindings/net/dsa/mediatek,mt7530.yaml | 17 ++---
.../bindings/net/dsa/microchip,ksz.yaml | 2 +-
.../bindings/net/dsa/microchip,lan937x.yaml | 2 +-
.../bindings/net/dsa/mscc,ocelot.yaml | 2 +-
.../bindings/net/dsa/nxp,sja1105.yaml | 2 +-
.../devicetree/bindings/net/dsa/qca8k.yaml | 15 +----
.../devicetree/bindings/net/dsa/realtek.yaml | 2 +-
.../bindings/net/dsa/renesas,rzn1-a5psw.yaml | 2 +-
.../bindings/net/ethernet-switch-port.yaml | 25 ++++++++
.../bindings/net/ethernet-switch.yaml | 62 +++++++++++++++++++
.../bindings/net/mscc,vsc7514-switch.yaml | 31 +---------
MAINTAINERS | 2 +
18 files changed, 134 insertions(+), 112 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/ethernet-switch-port.yaml
create mode 100644 Documentation/devicetree/bindings/net/ethernet-switch.yaml

--
2.25.1

From 20867224faa46fc375f31b11aece705af091151a Mon Sep 17 00:00:00 2001
From: Colin Foster <colin.foster@in-advantage.com>
Date: Thu, 3 Nov 2022 21:10:02 -0700
Subject: [PATCH v2 net-next 0/6] dt-binding preparation for ocelot switches
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Ocelot switches have the abilitiy to be used internally via
memory-mapped IO or externally via SPI or PCIe. This brings up issues
for documentation, where the same chip might be accessed internally in a
switchdev manner, or externally in a DSA configuration. This patch set
is perparation to bring DSA functionality to the VSC7512, utilizing as
much as possible with an almost identical VSC7514 chip.

During the most recent RFC for internal ethernet switch functionality to
the VSC7512, there were 10 steps laid out to adequately prepare
documentation:

https://lore.kernel.org/all/20221010174856.nd3n4soxk7zbmcm7@skbuf/

The full context is quoted below. This patch set represents steps 1-7 of
the 10 steps, with the remaining steps to likely be part of what was the
original RFC.

The first two patches are specifically rewording and fixing of the MFD
bindings. I kept them in this patch set since they might cause conflicts
with future documentation changes that will be part of the net-next
tree. I can separate them if desired.

Context:

```
To end the discussion on a constructive note, I think if I were Colin,
I would do the following, in the following order, according to what was
expressed as a constraint:

1. Reword the "driver" word out of mscc,vsc7514-switch.yaml and express
the description in terms of what the switch can do, not what the
driver can do.

2. Make qca8k.yaml have "$ref: dsa.yaml#". Remove "$ref: dsa-port.yaml#"
from the same schema.

3. Remove "- $ref: dsa-port.yaml#" from mediatek,mt7530.yaml. It doesn't
seem to be needed, since dsa.yaml also has this. We need this because
we want to make sure no one except dsa.yaml references dsa-port.yaml.

4. Move the DSA-unspecific portion from dsa.yaml into a new
ethernet-switch.yaml. What remains in dsa.yaml is "dsa,member".
The dsa.yaml schema will have "$ref: ethernet-switch.yaml#" for the
"(ethernet-)switch" node, plus its custom additions.

5. Move the DSA-unspecific portion from dsa-port.yaml into a new
ethernet-switch-port.yaml. What remains in dsa-port.yaml is:
* ethernet phandle
* link phandle
* label property
* dsa-tag-protocol property
* the constraint that CPU and DSA ports must have phylink bindings

6. The ethernet-switch.yaml will have "$ref: ethernet-switch-port.yaml#"
and "$ref: dsa-port.yaml". The dsa-port.yaml schema will *not* have
"$ref: ethernet-switch-port.yaml#", just its custom additions.
I'm not 100% on this, but I think there will be a problem if:
- dsa.yaml references ethernet-switch.yaml
- ethernet-switch.yaml references ethernet-switch-port.yaml
- dsa.yaml also references dsa-port.yaml
- dsa-port.yaml references ethernet-switch-port.yaml
because ethernet-switch-port.yaml will be referenced twice. Again,
not sure if this is a problem. If it isn't, things can be simpler,
just make dsa-port.yaml reference ethernet-switch-port.yaml, and skip
steps 2 and 3 since dsa-port.yaml containing just the DSA specifics
is no longer problematic.

7. Make mscc,vsc7514-switch.yaml have "$ref: ethernet-switch.yaml#" for
the "mscc,vsc7514-switch.yaml" compatible string. This will eliminate
its own definitions for the generic properties: $nodename and
ethernet-ports (~45 lines of code if I'm not mistaken).

8. Introduce the "mscc,vsc7512-switch" compatible string as part of
mscc,vsc7514-switch.yaml, but this will have "$ref: dsa.yaml#" (this
will have to be referenced by full path because they are in different
folders) instead of "ethernet-switch.yaml". Doing this will include
the common bindings for a switch, plus the DSA specifics.

9. Optional: rework ti,cpsw-switch.yaml, microchip,lan966x-switch.yaml,
microchip,sparx5-switch.yaml to have "$ref: ethernet-switch.yaml#"
which should reduce some duplication in existing schemas.

10. Question for future support of VSC7514 in DSA mode: how do we decide
whether to $ref: ethernet-switch.yaml or dsa.yaml? If the parent MFD
node has a compatible string similar to "mscc,vsc7512", then use DSA,
otherwise use generic ethernet-switch?
```

Colin Foster (6):
dt-bindings: net: dsa: allow additional ethernet-port properties
dt-bindings: net: dsa: qca8k: utilize shared dsa.yaml
dt-bindings: net: dsa: mediatek,mt7530: remove unnecessary dsa-port
reference
dt-bindings: net: add generic ethernet-switch
dt-bindings: net: add generic ethernet-switch-port binding
dt-bindings: net: mscc,vsc7514-switch: utilize generic
ethernet-switch.yaml

.../devicetree/bindings/net/dsa/dsa-port.yaml | 27 +---------
.../devicetree/bindings/net/dsa/dsa.yaml | 26 +---------
.../bindings/net/dsa/mediatek,mt7530.yaml | 3 --
.../devicetree/bindings/net/dsa/qca8k.yaml | 18 +++----
.../bindings/net/ethernet-switch-port.yaml | 44 ++++++++++++++++
.../bindings/net/ethernet-switch.yaml | 51 +++++++++++++++++++
.../bindings/net/mscc,vsc7514-switch.yaml | 40 ++-------------
MAINTAINERS | 2 +
8 files changed, 112 insertions(+), 99 deletions(-)
create mode 100644 Documentation/devicetree/bindings/net/ethernet-switch-port.yaml
create mode 100644 Documentation/devicetree/bindings/net/ethernet-switch.yaml

--
2.25.1