Hi Michael,
On Fri, 2022-08-26 at 13:56 +0200, Michael Walle wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Originally this was used in by the switch core driver to issue a reset.
> But it turns out, this isn't just a switch core reset but instead it
> will reset almost the complete SoC.
>
> Instead of adding almost all devices of the SoC a shared reset line,
> issue the reset once early on startup. Keep the reset controller for
> backwards compatibility, but make the actual reset a noop.
>
> Suggested-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> Signed-off-by: Michael Walle <michael@xxxxxxxx>
> ---
> drivers/reset/reset-microchip-sparx5.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
> index 00b612a0effa..f3528dd1d084 100644
> --- a/drivers/reset/reset-microchip-sparx5.c
> +++ b/drivers/reset/reset-microchip-sparx5.c
> @@ -33,11 +33,8 @@ static struct regmap_config sparx5_reset_regmap_config = {
> .reg_stride = 4,
> };
>
> -static int sparx5_switch_reset(struct reset_controller_dev *rcdev,
> - unsigned long id)
> +static int sparx5_switch_reset(struct mchp_reset_context *ctx)
> {
> - struct mchp_reset_context *ctx =
> - container_of(rcdev, struct mchp_reset_context, rcdev);
> u32 val;
>
> /* Make sure the core is PROTECTED from reset */
> @@ -54,8 +51,14 @@ static int sparx5_switch_reset(struct reset_controller_dev *rcdev,
> 1, 100);
> }
>
> +static int sparx5_reset_noop(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return 0;
> +}
> +
> static const struct reset_control_ops sparx5_reset_ops = {
> - .reset = sparx5_switch_reset,
> + .reset = sparx5_reset_noop,
> };
>
> static int mchp_sparx5_map_syscon(struct platform_device *pdev, char *name,
> @@ -122,6 +125,11 @@ static int mchp_sparx5_reset_probe(struct platform_device *pdev)
> ctx->rcdev.of_node = dn;
> ctx->props = device_get_match_data(&pdev->dev);
>
> + /* Issue the reset very early, our actual reset callback is a noop. */
> + err = sparx5_switch_reset(ctx);
> + if (err)
> + return err;
> +
> return devm_reset_controller_register(&pdev->dev, &ctx->rcdev);
> }
>
> @@ -163,6 +171,10 @@ static int __init mchp_sparx5_reset_init(void)
> return platform_driver_register(&mchp_sparx5_reset_driver);
> }
>
> +/*
> + * Because this is a global reset, keep this postcore_initcall() to issue the
> + * reset as early as possible during the kernel startup.
> + */
> postcore_initcall(mchp_sparx5_reset_init);
>
> MODULE_DESCRIPTION("Microchip Sparx5 switch reset driver");
> --
> 2.30.2
>
Tested-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx> on Sparx5
BR
Steen
