2023-10-12 22:36:28

by Linus Walleij

[permalink] [raw]
Subject: [PATCH 0/3] Create a binding for the Marvell MV88E6xxx DSA switches

This shows the path we could take with this, deprecating the
weird external bus thing.

I don't know what to do about the irq lines with a pointless
type flag that should be onecell:ed.

I need proper schema checking to add LED support to the
Marvell switch. Just how it is, it can't go on like this.

Andrew: if you have lots of ideas and want to do lots of
changes, feel free to just take over the patch set and do
what you like, this is an RFC after all.

Signed-off-by: Linus Walleij <[email protected]>
---
Linus Walleij (3):
ARM: dts: marvell: Fix some common switch mistakes
RFC: dt-bindings: marvell: Rewrite in schema
RFC: net: dsa: mv88e6xxx: Register mdio-external

.../bindings/net/dsa/marvell,mv88e6xxx.yaml | 249 +++++++++++++++++++++
.../devicetree/bindings/net/dsa/marvell.txt | 109 ---------
MAINTAINERS | 2 +-
arch/arm/boot/dts/marvell/armada-370-rd.dts | 2 -
.../dts/marvell/armada-381-netgear-gs110emx.dts | 2 -
.../dts/marvell/armada-385-clearfog-gtr-l8.dts | 2 +-
.../dts/marvell/armada-385-clearfog-gtr-s4.dts | 2 +-
arch/arm/boot/dts/marvell/armada-385-linksys.dtsi | 2 -
arch/arm/boot/dts/marvell/armada-388-clearfog.dts | 2 -
.../boot/dts/marvell/armada-xp-linksys-mamba.dts | 2 -
drivers/net/dsa/mv88e6xxx/chip.c | 16 +-
11 files changed, 267 insertions(+), 123 deletions(-)
---
base-commit: 69d714c69583c4387147d0b7f2f436d42baddadd
change-id: 20231008-marvell-88e6152-wan-led-88c43b7fd2fd

Best regards,
--
Linus Walleij <[email protected]>


2023-10-12 22:36:44

by Linus Walleij

[permalink] [raw]
Subject: [PATCH 3/3] RFC: net: dsa: mv88e6xxx: Register mdio-external

Make it legal to have a subnode just named "mdio-external"
and have that be recognized immediately as the external
MDIO bus, register it and return. Only fallback to the
old method with a compatible in the external bus node
if this doesn't work.

This is the result of deprecating the old DT method
of providing a node "mdio1" with a compatible string.

Signed-off-by: Linus Walleij <[email protected]>
---
drivers/net/dsa/mv88e6xxx/chip.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index 52a99d8bada0..05f6776885f6 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -3676,7 +3676,21 @@ static int mv88e6xxx_mdios_register(struct mv88e6xxx_chip *chip)
if (err)
return err;

- /* Walk the device tree, and see if there are any other nodes
+ /* If the optional external bus is explicitly named as such,
+ * just register it and be done with this.
+ */
+ child = of_get_child_by_name(np, "mdio-external");
+ if (child) {
+ err = mv88e6xxx_mdio_register(chip, child, true);
+ of_node_put(child);
+ if (err)
+ return err;
+ return 0;
+ }
+
+ /* Deprecated binding with compatible:
+ *
+ * Walk the device tree, and see if there are any other nodes
* which say they are compatible with the external mdio
* bus.
*/

--
2.41.0

2023-10-12 22:37:10

by Linus Walleij

[permalink] [raw]
Subject: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema

This is an attempt to rewrite the Marvell MV88E6xxx switch bindings
in YAML schema.

The current text binding says:
WARNING: This binding is currently unstable. Do not program it into a
FLASH never to be changed again. Once this binding is stable, this
warning will be removed.

Well that never happened before we switched to YAML markup,
we can't have it like this, what about fixing the mess?

Signed-off-by: Linus Walleij <[email protected]>
---
.../bindings/net/dsa/marvell,mv88e6xxx.yaml | 249 +++++++++++++++++++++
.../devicetree/bindings/net/dsa/marvell.txt | 109 ---------
MAINTAINERS | 2 +-
3 files changed, 250 insertions(+), 110 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.yaml b/Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.yaml
new file mode 100644
index 000000000000..8ff94e8b89da
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.yaml
@@ -0,0 +1,249 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/dsa/marvell,mv88e6xxx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell MV88E6xxx switch family
+
+maintainers:
+ - Andrew Lunn <[email protected]>
+
+description:
+ The Marvell MV88E6xxx switch series has been produced and sold
+ by Marvell since at least 2010. The switch has a few compatibles which
+ just indicate the base address of the switch, then operating systems
+ can investigate switch ID registers to find out which actual version
+ of the switch it is dealing with.
+
+properties:
+ compatible:
+ oneOf:
+ - enum:
+ - marvell,mv88e6060
+ - marvell,mv88e6085
+ - marvell,mv88e6190
+ - marvell,mv88e6250
+ description: |
+ marvell,mv88e6060: The oldest Marvell switch supported (singular version)
+ marvell,mv88e6085: This switch uses base address 0x10.
+ This switch and its siblings will be autodetected from
+ ID registers found in the switch, so only "marvell,mv88e6085" should be
+ specified. This includes the following list of MV88Exxxx switches:
+ 6085, 6095, 6097, 6123, 6131, 6141, 6161, 6165, 6171, 6172, 6175, 6176,
+ 6185, 6240, 6320, 6321, 6341, 6350, 6351, 6352
+ marvell,mv88e6190: This switch uses base address 0x00.
+ This switch and its siblings will be autodetected from
+ ID registers found in the switch, so only "marvell,mv88e6190" should be
+ specified. This includes the following list of MV88Exxxx switches:
+ 6190, 6190X, 6191, 6290, 6361, 6390, 6390X
+ marvell,mv88e6250: This switch uses base address 0x08 or 0x18.
+ This switch and its siblings will be autodetected from
+ ID registers found in the switch, so only "marvell,mv88e6250" should be
+ specified. This includes the following list of MV88Exxxx switches:
+ 6220, 6250
+ reg:
+ maxItems: 1
+
+ eeprom-length:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Set to the length of an EEPROM connected to the switch. Must be
+ set if the switch can not detect the presence and/or size of a connected
+ EEPROM, otherwise optional.
+
+ reset-gpios:
+ description:
+ GPIO to be used to reset the whole device
+ maxItems: 1
+
+ interrupts:
+ description: The switch provides an external interrupt line, but it is
+ not always used by target systems.
+ maxItems: 1
+
+ interrupt-controller:
+ description: The switch has an internal interrupt controller used by
+ the different sub-blocks.
+
+ '#interrupt-cells':
+ description: The internal interrupt controller only supports triggering
+ on IRQ_TYPE_LEVEL_HIGH
+ # FIXME: what is this? this should be one cell should it not?
+ # the Linux mv88e6xxx driver does not implement .irq_set_type in its irq_chip
+ # so at least in that implementation the type is flat out ignored.
+ const: 2
+
+ mdio:
+ $ref: /schemas/net/mdio.yaml#
+ unevaluatedProperties: false
+ description: Marvell MV88E6xxx switches have an internal mdio bus to
+ access switch ports, which is handled in this node.
+
+ mdio-external:
+ $ref: /schemas/net/mdio.yaml#
+ unevaluatedProperties: false
+ description: Marvell MV88E6xxx switches have an external mdio bus to
+ access switch ports.
+
+ mdio1:
+ $ref: /schemas/net/mdio.yaml#
+ unevaluatedProperties: false
+ description: Older version of mdio-external
+ deprecated: true
+ properties:
+ compatible:
+ const: marvell,mv88e6xxx-mdio-external
+
+ required:
+ - compatible
+
+$ref: dsa.yaml#
+
+patternProperties:
+ "^(ethernet-)?ports$":
+ type: object
+ patternProperties:
+ "^(ethernet-)?port@[0-9a-f]+$":
+ type: object
+ description: Ethernet switch ports
+
+ $ref: dsa-port.yaml#
+
+ unevaluatedProperties: false
+
+oneOf:
+ - required:
+ - ports
+ - required:
+ - ethernet-ports
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ switch0: switch@0 {
+ compatible = "marvell,mv88e6085";
+ reg = <0>;
+ reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
+ interrupt-parent = <&gpio0>;
+ interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+ label = "lan1";
+ };
+ port@1 {
+ reg = <1>;
+ label = "lan2";
+ };
+ port@2 {
+ reg = <2>;
+ label = "lan3";
+ };
+ port@3 {
+ reg = <3>;
+ label = "lan4";
+ };
+ port@4 {
+ reg = <4>;
+ label = "wan";
+ };
+
+ port@5 {
+ reg = <5>;
+ phy-mode = "sgmii";
+ ethernet = <&eth2>;
+
+ fixed-link {
+ speed = <1000>;
+ full-duplex;
+ };
+ };
+ };
+
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ switch0phy0: switch0phy@0 {
+ reg = <0>;
+ interrupt-parent = <&switch0>;
+ interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+ };
+ };
+ };
+ };
+
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ switch1: switch@0 {
+ compatible = "marvell,mv88e6190";
+ reg = <0>;
+ reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
+ interrupt-parent = <&gpio0>;
+ interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+ label = "lan1";
+ };
+ port@1 {
+ reg = <1>;
+ label = "lan2";
+ };
+ port@2 {
+ reg = <2>;
+ label = "lan3";
+ };
+ port@3 {
+ reg = <3>;
+ label = "lan4";
+ };
+ };
+
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ switch1phy0: switch1phy@0 {
+ reg = <0>;
+ interrupt-parent = <&switch1>;
+ interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+ };
+ };
+
+ mdio-external {
+ compatible = "marvell,mv88e6xxx-mdio-external";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ switch1phy9: switch1phy@9 {
+ reg = <9>;
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/net/dsa/marvell.txt b/Documentation/devicetree/bindings/net/dsa/marvell.txt
deleted file mode 100644
index 6ec0c181b6db..000000000000
--- a/Documentation/devicetree/bindings/net/dsa/marvell.txt
+++ /dev/null
@@ -1,109 +0,0 @@
-Marvell DSA Switch Device Tree Bindings
----------------------------------------
-
-WARNING: This binding is currently unstable. Do not program it into a
-FLASH never to be changed again. Once this binding is stable, this
-warning will be removed.
-
-If you need a stable binding, use the old dsa.txt binding.
-
-Marvell Switches are MDIO devices. The following properties should be
-placed as a child node of an mdio device.
-
-The properties described here are those specific to Marvell devices.
-Additional required and optional properties can be found in dsa.txt.
-
-The compatibility string is used only to find an identification register,
-which is at a different MDIO base address in different switch families.
-- "marvell,mv88e6085" : Switch has base address 0x10. Use with models:
- 6085, 6095, 6097, 6123, 6131, 6141, 6161, 6165,
- 6171, 6172, 6175, 6176, 6185, 6240, 6320, 6321,
- 6341, 6350, 6351, 6352
-- "marvell,mv88e6190" : Switch has base address 0x00. Use with models:
- 6190, 6190X, 6191, 6290, 6361, 6390, 6390X
-- "marvell,mv88e6250" : Switch has base address 0x08 or 0x18. Use with model:
- 6220, 6250
-
-Required properties:
-- compatible : Should be one of "marvell,mv88e6085",
- "marvell,mv88e6190" or "marvell,mv88e6250" as
- indicated above
-- reg : Address on the MII bus for the switch.
-
-Optional properties:
-
-- reset-gpios : Should be a gpio specifier for a reset line
-- interrupts : Interrupt from the switch
-- interrupt-controller : Indicates the switch is itself an interrupt
- controller. This is used for the PHY interrupts.
-#interrupt-cells = <2> : Controller uses two cells, number and flag
-- eeprom-length : Set to the length of an EEPROM connected to the
- switch. Must be set if the switch can not detect
- the presence and/or size of a connected EEPROM,
- otherwise optional.
-- mdio : Container of PHY and devices on the switches MDIO
- bus.
-- mdio? : Container of PHYs and devices on the external MDIO
- bus. The node must contains a compatible string of
- "marvell,mv88e6xxx-mdio-external"
-
-Example:
-
- mdio {
- #address-cells = <1>;
- #size-cells = <0>;
- interrupt-parent = <&gpio0>;
- interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
- interrupt-controller;
- #interrupt-cells = <2>;
-
- switch0: switch@0 {
- compatible = "marvell,mv88e6085";
- reg = <0>;
- reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
-
- mdio {
- #address-cells = <1>;
- #size-cells = <0>;
- switch1phy0: switch1phy0@0 {
- reg = <0>;
- interrupt-parent = <&switch0>;
- interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
- };
- };
- };
- };
-
- mdio {
- #address-cells = <1>;
- #size-cells = <0>;
- interrupt-parent = <&gpio0>;
- interrupts = <27 IRQ_TYPE_LEVEL_LOW>;
- interrupt-controller;
- #interrupt-cells = <2>;
-
- switch0: switch@0 {
- compatible = "marvell,mv88e6190";
- reg = <0>;
- reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;
-
- mdio {
- #address-cells = <1>;
- #size-cells = <0>;
- switch1phy0: switch1phy0@0 {
- reg = <0>;
- interrupt-parent = <&switch0>;
- interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
- };
- };
-
- mdio1 {
- compatible = "marvell,mv88e6xxx-mdio-external";
- #address-cells = <1>;
- #size-cells = <0>;
- switch1phy9: switch1phy0@9 {
- reg = <9>;
- };
- };
- };
- };
diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..1b4475254d27 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12625,7 +12625,7 @@ MARVELL 88E6XXX ETHERNET SWITCH FABRIC DRIVER
M: Andrew Lunn <[email protected]>
L: [email protected]
S: Maintained
-F: Documentation/devicetree/bindings/net/dsa/marvell.txt
+F: Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.yaml
F: Documentation/networking/devlink/mv88e6xxx.rst
F: drivers/net/dsa/mv88e6xxx/
F: include/linux/dsa/mv88e6xxx.h

--
2.41.0

2023-10-12 23:26:56

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema


On Fri, 13 Oct 2023 00:35:15 +0200, Linus Walleij wrote:
> This is an attempt to rewrite the Marvell MV88E6xxx switch bindings
> in YAML schema.
>
> The current text binding says:
> WARNING: This binding is currently unstable. Do not program it into a
> FLASH never to be changed again. Once this binding is stable, this
> warning will be removed.
>
> Well that never happened before we switched to YAML markup,
> we can't have it like this, what about fixing the mess?
>
> Signed-off-by: Linus Walleij <[email protected]>
> ---
> .../bindings/net/dsa/marvell,mv88e6xxx.yaml | 249 +++++++++++++++++++++
> .../devicetree/bindings/net/dsa/marvell.txt | 109 ---------
> MAINTAINERS | 2 +-
> 3 files changed, 250 insertions(+), 110 deletions(-)
>

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/net/marvell,mvusb.example.dtb: switch@0: ports: '#address-cells' is a required property
from schema $id: http://devicetree.org/schemas/net/dsa/marvell,mv88e6xxx.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/net/marvell,mvusb.example.dtb: switch@0: ports: '#size-cells' is a required property
from schema $id: http://devicetree.org/schemas/net/dsa/marvell,mv88e6xxx.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.example.dtb: switch@0: mdio-external: Unevaluated properties are not allowed ('compatible' was unexpected)
from schema $id: http://devicetree.org/schemas/net/dsa/marvell,mv88e6xxx.yaml#
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/net/dsa/marvell,mv88e6xxx.example.dtb: switch@0: Unevaluated properties are not allowed ('mdio-external' was unexpected)
from schema $id: http://devicetree.org/schemas/net/dsa/marvell,mv88e6xxx.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/[email protected]

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

2023-10-13 12:43:32

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema

> +properties:
> + compatible:
> + oneOf:
> + - enum:
> + - marvell,mv88e6060

The 6060 is a separate driver. Its not part of mv88e6xxx. So it should
have a binding document of its own.

> + '#interrupt-cells':
> + description: The internal interrupt controller only supports triggering
> + on IRQ_TYPE_LEVEL_HIGH
> + # FIXME: what is this? this should be one cell should it not?
> + # the Linux mv88e6xxx driver does not implement .irq_set_type in its irq_chip
> + # so at least in that implementation the type is flat out ignored.
> + const: 2

This interrupt controller is for the embedded PHYs. Its is hard wired
active high.

> + mdio-external:
> + $ref: /schemas/net/mdio.yaml#
> + unevaluatedProperties: false
> + description: Marvell MV88E6xxx switches have an external mdio bus to
> + access switch ports.

This is used to access external PHYs attached to the ports, not the
ports themselves.

> +
> + mdio1:
> + $ref: /schemas/net/mdio.yaml#
> + unevaluatedProperties: false
> + description: Older version of mdio-external
> + deprecated: true
> + properties:
> + compatible:
> + const: marvell,mv88e6xxx-mdio-external

The driver only looks at the compatible. It does not care what the
node is called. So you are going to need to change the driver if you
want this in the schema.

Andrew

2023-10-13 12:46:29

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH 3/3] RFC: net: dsa: mv88e6xxx: Register mdio-external

On Fri, Oct 13, 2023 at 12:35:16AM +0200, Linus Walleij wrote:
> Make it legal to have a subnode just named "mdio-external"
> and have that be recognized immediately as the external
> MDIO bus, register it and return. Only fallback to the
> old method with a compatible in the external bus node
> if this doesn't work.
>
> This is the result of deprecating the old DT method
> of providing a node "mdio1" with a compatible string.

What is missing from this description is why do you want to deprecate
the old method? What is wrong with it?

Andrew

2023-10-13 13:04:44

by Linus Walleij

[permalink] [raw]
Subject: Re: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema

Hi Andrew,

thanks for reviewing!

On Fri, Oct 13, 2023 at 2:43 PM Andrew Lunn <[email protected]> wrote:

> > +properties:
> > + compatible:
> > + oneOf:
> > + - enum:
> > + - marvell,mv88e6060
>
> The 6060 is a separate driver. Its not part of mv88e6xxx. So it should
> have a binding document of its own.

It really doesn't matter to the DT bindings.
It is not the job of DT to reflect the state of Linux.

In another operating system they might all be the same driver.
Or all four variants have their own driver.

If the hardware is distinctly different so a lot of the properties
are unique then it may be warranted with a separate DT
binding, for the sake of keeping bindings simpler and
coherent.

> > + '#interrupt-cells':
> > + description: The internal interrupt controller only supports triggering
> > + on IRQ_TYPE_LEVEL_HIGH
> > + # FIXME: what is this? this should be one cell should it not?
> > + # the Linux mv88e6xxx driver does not implement .irq_set_type in its irq_chip
> > + # so at least in that implementation the type is flat out ignored.
> > + const: 2
>
> This interrupt controller is for the embedded PHYs. Its is hard wired
> active high.

Hmm.... I need feedback from the DT people here. It does have a
polarity, but the polarity cannot be changed. So shall we encode this
always the same polarity in the flags cell or skip it altogether?

I'm uncertain. The currens scheme does reflect a reality.

> > + mdio1:
> > + $ref: /schemas/net/mdio.yaml#
> > + unevaluatedProperties: false
> > + description: Older version of mdio-external
> > + deprecated: true
> > + properties:
> > + compatible:
> > + const: marvell,mv88e6xxx-mdio-external
>
> The driver only looks at the compatible. It does not care what the
> node is called. So you are going to need to change the driver if you
> want this in the schema.

Yeah, thats what patch 3/3 does :D

Yours,
Linus Walleij

2023-10-13 14:16:29

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 3/3] RFC: net: dsa: mv88e6xxx: Register mdio-external

On Fri, Oct 13, 2023 at 12:35:16AM +0200, Linus Walleij wrote:
> Make it legal to have a subnode just named "mdio-external"
> and have that be recognized immediately as the external
> MDIO bus, register it and return. Only fallback to the
> old method with a compatible in the external bus node
> if this doesn't work.
>
> This is the result of deprecating the old DT method
> of providing a node "mdio1" with a compatible string.

I think this is the wrong direction. Using compatible is much better
than relying on node names. We've been "fixing" node names precisely
because they are usually not ABI.

Rob

2023-10-13 14:18:42

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema

On Fri, Oct 13, 2023 at 03:04:10PM +0200, Linus Walleij wrote:
> Hi Andrew,
>
> thanks for reviewing!
>
> On Fri, Oct 13, 2023 at 2:43 PM Andrew Lunn <[email protected]> wrote:
>
> > > +properties:
> > > + compatible:
> > > + oneOf:
> > > + - enum:
> > > + - marvell,mv88e6060
> >
> > The 6060 is a separate driver. Its not part of mv88e6xxx. So it should
> > have a binding document of its own.
>
> It really doesn't matter to the DT bindings.
> It is not the job of DT to reflect the state of Linux.
>
> In another operating system they might all be the same driver.
> Or all four variants have their own driver.
>
> If the hardware is distinctly different so a lot of the properties
> are unique then it may be warranted with a separate DT
> binding, for the sake of keeping bindings simpler and
> coherent.

Exactly.

>
> > > + '#interrupt-cells':
> > > + description: The internal interrupt controller only supports triggering
> > > + on IRQ_TYPE_LEVEL_HIGH
> > > + # FIXME: what is this? this should be one cell should it not?
> > > + # the Linux mv88e6xxx driver does not implement .irq_set_type in its irq_chip
> > > + # so at least in that implementation the type is flat out ignored.
> > > + const: 2
> >
> > This interrupt controller is for the embedded PHYs. Its is hard wired
> > active high.
>
> Hmm.... I need feedback from the DT people here. It does have a
> polarity, but the polarity cannot be changed. So shall we encode this
> always the same polarity in the flags cell or skip it altogether?
>
> I'm uncertain. The currens scheme does reflect a reality.

Either way is fine. If users are already doing 2 cells, then I'd
probably just keep that and state that the flags cell is ignored/unused.

Rob

2023-10-13 15:41:29

by Andrew Lunn

[permalink] [raw]
Subject: Re: [PATCH 2/3] RFC: dt-bindings: marvell: Rewrite in schema

On Fri, Oct 13, 2023 at 03:04:10PM +0200, Linus Walleij wrote:
> Hi Andrew,
>
> thanks for reviewing!
>
> On Fri, Oct 13, 2023 at 2:43 PM Andrew Lunn <[email protected]> wrote:
>
> > > +properties:
> > > + compatible:
> > > + oneOf:
> > > + - enum:
> > > + - marvell,mv88e6060
> >
> > The 6060 is a separate driver. Its not part of mv88e6xxx. So it should
> > have a binding document of its own.
>
> It really doesn't matter to the DT bindings.
> It is not the job of DT to reflect the state of Linux.
>
> In another operating system they might all be the same driver.
> Or all four variants have their own driver.
>
> If the hardware is distinctly different so a lot of the properties
> are unique then it may be warranted with a separate DT
> binding, for the sake of keeping bindings simpler and
> coherent.

What i want to avoid is giving the impression that the mv88e6060
implements something when in fact it does not. That device does not
have the interrupt controller, so all the interrupt properties are
invalid for it. The hardware does not allow access to the EEPROM, so
the EEPROM length property is not valid, etc.

If you do want to make it part of the binding, it would be good to add
constraints based on the compatible to indicate which properties are
actually valid for the hardware.

The 88e6060 actually has an open datasheet.

https://www.insidegadgets.com/wp-content/uploads/2014/07/88E6060.pdf

Andrew