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[1/3] reset: microchip-sparx5: issue a reset on startup

Message ID 20220826115607.1148489-2-michael@walle.cc (mailing list archive)
State Not Applicable
Headers show
Series reset: microchip-sparx5: fix the broken switch reset | expand

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Commit Message

Michael Walle Aug. 26, 2022, 11:56 a.m. UTC
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@pengutronix.de>
Signed-off-by: Michael Walle <michael@walle.cc>
---
 drivers/reset/reset-microchip-sparx5.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

Comments

Steen Hegelund Aug. 29, 2022, 9:14 a.m. UTC | #1
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@pengutronix.de>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
>  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@microchip.com> on Sparx5

BR
Steen
Michael Walle Aug. 29, 2022, 9:22 a.m. UTC | #2
Hi Steen,

Am 2022-08-29 11:14, schrieb Steen Hegelund:
> 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@pengutronix.de>
>> Signed-off-by: Michael Walle <michael@walle.cc>
..

> Tested-by: Steen Hegelund <Steen.Hegelund@microchip.com> on Sparx5

Thanks for testing!

-michael
Philipp Zabel Aug. 30, 2022, 4:46 p.m. UTC | #3
On Fr, 2022-08-26 at 13:56 +0200, Michael Walle wrote:
> 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@pengutronix.de>
> Signed-off-by: Michael Walle <michael@walle.cc>

I've applied this patch to the reset/fixes branch.

regards
Philipp
diff mbox series

Patch

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");