2020-11-16 17:16:21

by Gregory CLEMENT

Subject: [PATCH 1/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property

From: Lars Povlsen <[email protected]>

This documents the 'microchip,reset-switch-core' property in the
ocelot-reset driver.

Signed-off-by: Lars Povlsen <[email protected]>
---
.../devicetree/bindings/power/reset/ocelot-reset.txt | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
index 4d530d815484..20fff03753ad 100644
--- a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
+++ b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
@@ -9,9 +9,15 @@ microchip Sparx5 armv8 SoC's.
Required Properties:
- compatible: "mscc,ocelot-chip-reset" or "microchip,sparx5-chip-reset"

+Optional properties:
+- microchip,reset-switch-core : Perform a switch core reset at the
+ time of driver load. This is may be used to initialize the switch
+ core to a known state (before other drivers are loaded).
+
Example:
reset@1070008 {
compatible = "mscc,ocelot-chip-reset";
reg = <0x1070008 0x4>;
+ microchip,reset-switch-core;
};

--
2.29.2

2020-11-18 11:03:42

by Alexandre Belloni

Subject: Re: [PATCH 1/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property

On 16/11/2020 18:11:55+0100, Gregory CLEMENT wrote:
> From: Lars Povlsen <[email protected]>
>
> This documents the 'microchip,reset-switch-core' property in the
> ocelot-reset driver.
>
> Signed-off-by: Lars Povlsen <[email protected]>
> ---
> .../devicetree/bindings/power/reset/ocelot-reset.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> index 4d530d815484..20fff03753ad 100644
> --- a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> +++ b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> @@ -9,9 +9,15 @@ microchip Sparx5 armv8 SoC's.
> Required Properties:
> - compatible: "mscc,ocelot-chip-reset" or "microchip,sparx5-chip-reset"
>
> +Optional properties:
> +- microchip,reset-switch-core : Perform a switch core reset at the
> + time of driver load. This is may be used to initialize the switch
> + core to a known state (before other drivers are loaded).
> +

If this is to be used by the switchdev driver, then I would simply
register this reset as a proper reset controller (with the driver/reset
API) and consume that from the switchdev driver.

However, the switch may also be configured from userspace in existing
products. In this case you'd have to expose a reset interface, either
from the drivers/reset core or with a specific consumer.

My point is that this property is not necessary.

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com