[PATCH 0/3] Expose REFCLK for RMII and enable RMII

[PATCH 0/3] Expose REFCLK for RMII and enable RMII

[Ryan.Wanner]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

This set allows the REFCLK property to be exposed as a dt-property to
properly reflect the correct RMII layout. RMII can take an external or
internal provided REFCLK, since this is not SoC dependent but board
dependent this must be exposed as a DT property for the macb driver.

This set also enables RMII mode for the SAMA7 SoCs gigabit mac.

Ryan Wanner (3):
  dt-bindings: net: cdns,macb: Add external REFCLK property
  net: cadence: macb: Expose REFCLK as a device tree property
  net: cadence: macb: Enable RMII for SAMA7 gem

 Documentation/devicetree/bindings/net/cdns,macb.yaml | 7 +++++++
 drivers/net/ethernet/cadence/macb_main.c             | 6 ++++++
 2 files changed, 13 insertions(+)

-- 
2.43.0

[PATCH 1/3] dt-bindings: net: cdns,macb: Add external REFCLK property

[Ryan.Wanner]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

REFCLK can be provided by an external source so this should be exposed
by a DT property. The REFCLK is used for RMII and in some SoCs that use
this driver the RGMII 125MHz clk can also be provided by an external
source.

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
---
 Documentation/devicetree/bindings/net/cdns,macb.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/cdns,macb.yaml b/Documentation/devicetree/bindings/net/cdns,macb.yaml
index 8d69846b2e09..e69f60c37793 100644
--- a/Documentation/devicetree/bindings/net/cdns,macb.yaml
+++ b/Documentation/devicetree/bindings/net/cdns,macb.yaml
@@ -114,6 +114,13 @@ properties:
   power-domains:
     maxItems: 1
 
+  cdns,refclk-ext:
+    type: boolean
+    description:
+      This selects if the REFCLK for RMII is provided by an external source.
+      For RGMII mode this selects if the 125MHz REF clock is provided by an external
+      source.
+
   cdns,rx-watermark:
     $ref: /schemas/types.yaml#/definitions/uint32
     description:
-- 
2.43.0

[PATCH 2/3] net: cadence: macb: Expose REFCLK as a device tree property

[Ryan.Wanner]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

The RMII and RGMII can both support internal or external provided
REFCLKs 50MHz and 125MHz respectively. Since this is dependent on
the board that the SoC is on this needs to be set via the device tree.

This property flag is checked in the MACB DT node so the REFCLK cap is
configured the correct way for the RMII or RGMII is configured on the
board.

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index d1f1ae5ea161..146e532543a1 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4109,6 +4109,8 @@ static const struct net_device_ops macb_netdev_ops = {
 static void macb_configure_caps(struct macb *bp,
 				const struct macb_config *dt_conf)
 {
+	struct device_node *np = bp->pdev->dev.of_node;
+	bool refclk_ext = of_property_present(np, "cdns,refclk-ext");
 	u32 dcfg;
 
 	if (dt_conf)
@@ -4141,6 +4143,9 @@ static void macb_configure_caps(struct macb *bp,
 		}
 	}
 
+	if (refclk_ext)
+		bp->caps |= MACB_CAPS_USRIO_HAS_CLKEN;
+
 	dev_dbg(&bp->pdev->dev, "Cadence caps 0x%08x\n", bp->caps);
 }
 
-- 
2.43.0

[PATCH 3/3] net: cadence: macb: Enable RMII for SAMA7 gem

[Ryan.Wanner]

From: Ryan Wanner <Ryan.Wanner@microchip.com>

This macro enables the RMII mode bit in the USRIO register when RMII
mode is requested.

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 146e532543a1..f4f922915ade 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -5101,6 +5101,7 @@ static const struct macb_config mpfs_config = {
 
 static const struct macb_config sama7g5_gem_config = {
 	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_CLK_HW_CHG |
+		MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII |
 		MACB_CAPS_MIIONRGMII | MACB_CAPS_GEM_HAS_PTP,
 	.dma_burst_length = 16,
 	.clk_init = macb_clk_init,
-- 
2.43.0

Re: [PATCH 2/3] net: cadence: macb: Expose REFCLK as a device tree property

[Simon Horman]

On Thu, Jun 19, 2025 at 10:04:14AM -0700, Ryan.Wanner@microchip.com wrote:
> From: Ryan Wanner <Ryan.Wanner@microchip.com>
> 
> The RMII and RGMII can both support internal or external provided
> REFCLKs 50MHz and 125MHz respectively. Since this is dependent on
> the board that the SoC is on this needs to be set via the device tree.
> 
> This property flag is checked in the MACB DT node so the REFCLK cap is
> configured the correct way for the RMII or RGMII is configured on the
> board.
> 
> Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
> ---
>  drivers/net/ethernet/cadence/macb_main.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index d1f1ae5ea161..146e532543a1 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -4109,6 +4109,8 @@ static const struct net_device_ops macb_netdev_ops = {
>  static void macb_configure_caps(struct macb *bp,
>  				const struct macb_config *dt_conf)
>  {
> +	struct device_node *np = bp->pdev->dev.of_node;
> +	bool refclk_ext = of_property_present(np, "cdns,refclk-ext");
>  	u32 dcfg;

Hi Ryan,

Some minor feedback from my side.

1. of_property_read_bool() seems slightly more appropriate here
2. Please consider arranging local variables in Networking code
   in reverse xmas tree order - longest line to shortest.

   This tool can be helpful for this
   https://github.com/ecree-solarflare/xmastree

	struct device_node *np = bp->pdev->dev.of_node;
	bool refclk_ext;
	u32 dcfg;

	refclk_ext = of_property_read_bool(np, "cdns,refclk-ext");

...

Re: [PATCH 1/3] dt-bindings: net: cdns,macb: Add external REFCLK property

[Conor Dooley]

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On Thu, Jun 19, 2025 at 10:04:13AM -0700, Ryan.Wanner@microchip.com wrote:
> From: Ryan Wanner <Ryan.Wanner@microchip.com>
> 
> REFCLK can be provided by an external source so this should be exposed
> by a DT property. The REFCLK is used for RMII and in some SoCs that use
> this driver the RGMII 125MHz clk can also be provided by an external
> source.
> 
> Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
> ---
>  Documentation/devicetree/bindings/net/cdns,macb.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/cdns,macb.yaml b/Documentation/devicetree/bindings/net/cdns,macb.yaml
> index 8d69846b2e09..e69f60c37793 100644
> --- a/Documentation/devicetree/bindings/net/cdns,macb.yaml
> +++ b/Documentation/devicetree/bindings/net/cdns,macb.yaml
> @@ -114,6 +114,13 @@ properties:
>    power-domains:
>      maxItems: 1
>  
> +  cdns,refclk-ext:
> +    type: boolean
> +    description:
> +      This selects if the REFCLK for RMII is provided by an external source.
> +      For RGMII mode this selects if the 125MHz REF clock is provided by an external
> +      source.

If this gets a v2, is the distinction between RMII and RGMII worth
mentioning? Or is that mentioned because the property has no effect for
!{RGMII,RMII} usecases?
I'm okay with the property existing, though so
Acked-by: Conor Dooley <conor.dooley@microchip.com>
if it's the latter or with an improved description for the former.

> +
>    cdns,rx-watermark:
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
> -- 
> 2.43.0
> 

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Re: [PATCH 0/3] Expose REFCLK for RMII and enable RMII

[Andrew Lunn]

On Thu, Jun 19, 2025 at 10:04:12AM -0700, Ryan.Wanner@microchip.com wrote:
> From: Ryan Wanner <Ryan.Wanner@microchip.com>
> 
> This set allows the REFCLK property to be exposed as a dt-property to
> properly reflect the correct RMII layout. RMII can take an external or
> internal provided REFCLK, since this is not SoC dependent but board
> dependent this must be exposed as a DT property for the macb driver.

What board is going to use this? Do you have a patch for a .dts file?

	Andrew

Re: [PATCH 0/3] Expose REFCLK for RMII and enable RMII

[Ryan Wanner]

On 6/21/25 00:24, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Thu, Jun 19, 2025 at 10:04:12AM -0700, Ryan.Wanner@microchip.com wrote:
>> From: Ryan Wanner <Ryan.Wanner@microchip.com>
>>
>> This set allows the REFCLK property to be exposed as a dt-property to
>> properly reflect the correct RMII layout. RMII can take an external or
>> internal provided REFCLK, since this is not SoC dependent but board
>> dependent this must be exposed as a DT property for the macb driver.
> 
> What board is going to use this? Do you have a patch for a .dts file?

Our SAMA7D65_curiosity board has a connector that allows us to change
ethernet phys. Since some of the phys we have provide their own REFCLK
while others do not, this property needs to be added so we are able to
use all of these.

I do not have an exact .dts patch for this since our default is MPU
provides the REFCLK, this property will be used with dt-overlays that
match each phy that is connected.

Ryan
> 
>         Andrew

Re: [PATCH 0/3] Expose REFCLK for RMII and enable RMII

[Andrew Lunn]

> Our SAMA7D65_curiosity board has a connector that allows us to change
> ethernet phys. Since some of the phys we have provide their own REFCLK
> while others do not, this property needs to be added so we are able to
> use all of these.
> 
> I do not have an exact .dts patch for this since our default is MPU
> provides the REFCLK, this property will be used with dt-overlays that
> match each phy that is connected.

We generally don't allow a feature without a user. So please re-submit
this when you submit a DT overlay which can actually use it.

    Andrew

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