diff mbox series

[RFC,v3,net-next,02/10] dt-bindings: net: dsa: hellcreek: add missing CPU port phy-mode/fixed-link to example

Message ID 20220806141059.2498226-3-vladimir.oltean@nxp.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series Validate OF nodes for DSA shared ports | expand

Commit Message

Vladimir Oltean Aug. 6, 2022, 2:10 p.m. UTC
Looking at hellcreek_phylink_get_caps(), I see that depending on whether
is_100_mbits is set, speeds of 1G or of 100M will be advertised. The
de1soc_r1_pdata sets is_100_mbits to true.

The PHY modes declared in the capabilities are MII, RGMII and GMII. GMII
doesn't support 100Mbps, and as for RGMII, it would be a bit implausible
to me to support this PHY mode but limit it to only 25 MHz. So I've
settled on MII as a phy-mode in the example, and a fixed-link of
100Mbps.

As a side note, there exists such a thing as "rev-mii", because the MII
protocol is asymmetric, and "mii" is the designation for the MAC side
(expected to be connected to a PHY), and "rev-mii" is the designation
for the PHY side (expected to be connected to a MAC). I wonder whether
"mii" or "rev-mii" should actually be used here, since this is a CPU
port and presumably connected to another MAC.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
v2->v3: patch is new

 .../devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml   | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Kurt Kanzenbach Aug. 8, 2022, 5:31 a.m. UTC | #1
On Sat Aug 06 2022, Vladimir Oltean wrote:
> Looking at hellcreek_phylink_get_caps(), I see that depending on whether
> is_100_mbits is set, speeds of 1G or of 100M will be advertised. The
> de1soc_r1_pdata sets is_100_mbits to true.
>
> The PHY modes declared in the capabilities are MII, RGMII and GMII. GMII
> doesn't support 100Mbps, and as for RGMII, it would be a bit implausible
> to me to support this PHY mode but limit it to only 25 MHz. So I've
> settled on MII as a phy-mode in the example, and a fixed-link of
> 100Mbps.
>
> As a side note, there exists such a thing as "rev-mii", because the MII
> protocol is asymmetric, and "mii" is the designation for the MAC side
> (expected to be connected to a PHY), and "rev-mii" is the designation
> for the PHY side (expected to be connected to a MAC). I wonder whether
> "mii" or "rev-mii" should actually be used here, since this is a CPU
> port and presumably connected to another MAC.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Rob Herring Aug. 9, 2022, 8:11 p.m. UTC | #2
On Sat, 06 Aug 2022 17:10:51 +0300, Vladimir Oltean wrote:
> Looking at hellcreek_phylink_get_caps(), I see that depending on whether
> is_100_mbits is set, speeds of 1G or of 100M will be advertised. The
> de1soc_r1_pdata sets is_100_mbits to true.
> 
> The PHY modes declared in the capabilities are MII, RGMII and GMII. GMII
> doesn't support 100Mbps, and as for RGMII, it would be a bit implausible
> to me to support this PHY mode but limit it to only 25 MHz. So I've
> settled on MII as a phy-mode in the example, and a fixed-link of
> 100Mbps.
> 
> As a side note, there exists such a thing as "rev-mii", because the MII
> protocol is asymmetric, and "mii" is the designation for the MAC side
> (expected to be connected to a PHY), and "rev-mii" is the designation
> for the PHY side (expected to be connected to a MAC). I wonder whether
> "mii" or "rev-mii" should actually be used here, since this is a CPU
> port and presumably connected to another MAC.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
> ---
> v2->v3: patch is new
> 
>  .../devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml   | 6 ++++++
>  1 file changed, 6 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml b/Documentation/devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml
index 228683773151..1ff44dd68a61 100644
--- a/Documentation/devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/hirschmann,hellcreek.yaml
@@ -93,6 +93,12 @@  examples:
                     reg = <0>;
                     label = "cpu";
                     ethernet = <&gmac0>;
+                    phy-mode = "mii";
+
+                    fixed-link {
+                        speed = <100>;
+                        full-duplex;
+                    };
                 };
 
                 port@2 {