[PATCH net-next 1/2] net: dsa: vsc73xx: make RGMII delays configurable

[PATCH net-next 1/2] net: dsa: vsc73xx: make RGMII delays configurable

[Pawel Dembicki]

This patch switches hardcoded RGMII transmit/receive delay to
a configurable value. Delay values are taken from the properties of
the CPU port: 'tx-internal-delay-ps' and 'rx-internal-delay-ps'.

The default value is configured to 2.0 ns to maintain backward
compatibility with existing code.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 drivers/net/dsa/vitesse-vsc73xx-core.c | 68 ++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c
index d9d3e30fd47a..7d3c8176dff7 100644
--- a/drivers/net/dsa/vitesse-vsc73xx-core.c
+++ b/drivers/net/dsa/vitesse-vsc73xx-core.c
@@ -684,6 +684,67 @@ vsc73xx_update_vlan_table(struct vsc73xx *vsc, int port, u16 vid, bool set)
 	return vsc73xx_write_vlan_table_entry(vsc, vid, portmap);
 }
 
+static void vsc73xx_configure_rgmii_port_delay(struct dsa_switch *ds)
+{
+	/* Keep 2.0 ns delay for backward complatibility */
+	u32 tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_2_0_NS;
+	u32 rx_delay = VSC73XX_GMIIDELAY_GMII0_RXDELAY_2_0_NS;
+	struct dsa_port *dp = dsa_to_port(ds, CPU_PORT);
+	struct device_node *port_dn = dp->dn;
+	struct vsc73xx *vsc = ds->priv;
+	u32 delay;
+
+	if (!of_property_read_u32(port_dn, "tx-internal-delay-ps", &delay)) {
+		switch (delay) {
+		case 0:
+			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_NONE;
+			break;
+		case 1400:
+			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_1_4_NS;
+			break;
+		case 1700:
+			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_1_7_NS;
+			break;
+		case 2000:
+			break;
+		default:
+			dev_warn(vsc->dev,
+				 "Unsupported RGMII Transmit Clock Delay, set to 2.0 ns\n");
+			break;
+		}
+	} else {
+		dev_info(vsc->dev,
+			 "RGMII Transmit Clock Delay isn't configured, set to 2.0 ns\n");
+	}
+
+	if (!of_property_read_u32(port_dn, "rx-internal-delay-ps", &delay)) {
+		switch (delay) {
+		case 0:
+			rx_delay = VSC73XX_GMIIDELAY_GMII0_RXDELAY_NONE;
+			break;
+		case 1400:
+			rx_delay = VSC73XX_GMIIDELAY_GMII0_RXDELAY_1_4_NS;
+			break;
+		case 1700:
+			rx_delay = VSC73XX_GMIIDELAY_GMII0_RXDELAY_1_7_NS;
+			break;
+		case 2000:
+			break;
+		default:
+			dev_warn(vsc->dev,
+				 "Unsupported RGMII Receive Clock Delay value, set to 2.0 ns\n");
+			break;
+		}
+	} else {
+		dev_info(vsc->dev,
+			 "RGMII Receive Clock Delay isn't configured, set to 2.0 ns\n");
+	}
+
+	/* MII delay, set both GTX and RX delay */
+	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GMIIDELAY,
+		      tx_delay | rx_delay);
+}
+
 static int vsc73xx_setup(struct dsa_switch *ds)
 {
 	struct vsc73xx *vsc = ds->priv;
@@ -746,10 +807,9 @@ static int vsc73xx_setup(struct dsa_switch *ds)
 			      VSC73XX_MAC_CFG, VSC73XX_MAC_CFG_RESET);
 	}
 
-	/* MII delay, set both GTX and RX delay to 2 ns */
-	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GMIIDELAY,
-		      VSC73XX_GMIIDELAY_GMII0_GTXDELAY_2_0_NS |
-		      VSC73XX_GMIIDELAY_GMII0_RXDELAY_2_0_NS);
+	/* Configure RGMII delay */
+	vsc73xx_configure_rgmii_port_delay(ds);
+
 	/* Ingess VLAN reception mask (table 145) */
 	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANMASK,
 		      0xff);
-- 
2.34.1

[PATCH net-next 2/2] dt-bindings: net: dsa: vsc73xx: add {rx,tx}-internal-delay-ps

[Pawel Dembicki]

Add a schema validator to vitesse,vsc73xx.yaml for MAC-level RGMII delays
in the CPU port. Additionally, valid values for VSC73XX were defined,
and a common definition for the RX and TX valid range was created.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
---
 .../bindings/net/dsa/vitesse,vsc73xx.yaml     | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/vitesse,vsc73xx.yaml b/Documentation/devicetree/bindings/net/dsa/vitesse,vsc73xx.yaml
index b99d7a694b70..f0fb31ad5d60 100644
--- a/Documentation/devicetree/bindings/net/dsa/vitesse,vsc73xx.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/vitesse,vsc73xx.yaml
@@ -52,6 +52,25 @@ properties:
 allOf:
   - $ref: dsa.yaml#/$defs/ethernet-ports
 
+patternProperties:
+  "^(ethernet-)?ports$":
+    additionalProperties: true
+    patternProperties:
+      "^(ethernet-)?port@6$":
+        allOf:
+          - if:
+              properties:
+                phy-mode:
+                  contains:
+                    enum:
+                      - rgmii
+            then:
+              properties:
+                rx-internal-delay-ps:
+                  $ref: "#/$defs/internal-delay-ps"
+                tx-internal-delay-ps:
+                  $ref: "#/$defs/internal-delay-ps"
+
 # This checks if reg is a chipselect so the device is on an SPI
 # bus, the if-clause will fail if reg is a tuple such as for a
 # platform device.
@@ -67,6 +86,14 @@ required:
   - compatible
   - reg
 
+$defs:
+  internal-delay-ps:
+    description:
+      Disable tunable delay lines using 0 ps, or enable them and select
+      the phase between 1400 ps and 2000 ps in increments of 300 ps.
+    enum:
+      [0, 1400, 1700, 2000]
+
 unevaluatedProperties: false
 
 examples:
@@ -108,6 +135,8 @@ examples:
             reg = <6>;
             ethernet = <&gmac1>;
             phy-mode = "rgmii";
+            rx-internal-delay-ps = <0>;
+            tx-internal-delay-ps = <0>;
             fixed-link {
               speed = <1000>;
               full-duplex;
@@ -150,6 +179,8 @@ examples:
           ethernet-port@6 {
             reg = <6>;
             ethernet = <&enet0>;
+            rx-internal-delay-ps = <0>;
+            tx-internal-delay-ps = <0>;
             phy-mode = "rgmii";
             fixed-link {
               speed = <1000>;
-- 
2.34.1

Re: [PATCH net-next 1/2] net: dsa: vsc73xx: make RGMII delays configurable

[Andrew Lunn]

On Tue, Jul 16, 2024 at 08:37:34PM +0200, Pawel Dembicki wrote:
> This patch switches hardcoded RGMII transmit/receive delay to
> a configurable value. Delay values are taken from the properties of
> the CPU port: 'tx-internal-delay-ps' and 'rx-internal-delay-ps'.
> 
> The default value is configured to 2.0 ns to maintain backward
> compatibility with existing code.
> 
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
>  drivers/net/dsa/vitesse-vsc73xx-core.c | 68 ++++++++++++++++++++++++--
>  1 file changed, 64 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c
> index d9d3e30fd47a..7d3c8176dff7 100644
> --- a/drivers/net/dsa/vitesse-vsc73xx-core.c
> +++ b/drivers/net/dsa/vitesse-vsc73xx-core.c
> @@ -684,6 +684,67 @@ vsc73xx_update_vlan_table(struct vsc73xx *vsc, int port, u16 vid, bool set)
>  	return vsc73xx_write_vlan_table_entry(vsc, vid, portmap);
>  }
>  
> +static void vsc73xx_configure_rgmii_port_delay(struct dsa_switch *ds)
> +{
> +	/* Keep 2.0 ns delay for backward complatibility */
> +	u32 tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_2_0_NS;
> +	u32 rx_delay = VSC73XX_GMIIDELAY_GMII0_RXDELAY_2_0_NS;
> +	struct dsa_port *dp = dsa_to_port(ds, CPU_PORT);
> +	struct device_node *port_dn = dp->dn;
> +	struct vsc73xx *vsc = ds->priv;
> +	u32 delay;
> +
> +	if (!of_property_read_u32(port_dn, "tx-internal-delay-ps", &delay)) {
> +		switch (delay) {
> +		case 0:
> +			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_NONE;
> +			break;
> +		case 1400:
> +			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_1_4_NS;
> +			break;
> +		case 1700:
> +			tx_delay = VSC73XX_GMIIDELAY_GMII0_GTXDELAY_1_7_NS;
> +			break;
> +		case 2000:
> +			break;
> +		default:
> +			dev_warn(vsc->dev,
> +				 "Unsupported RGMII Transmit Clock Delay, set to 2.0 ns\n");

I would suggest you make this dev_err() and return -EINVAL. The DT has
a real error in it which should be fixed.

> +			break;
> +		}
> +	} else {
> +		dev_info(vsc->dev,
> +			 "RGMII Transmit Clock Delay isn't configured, set to 2.0 ns\n");

This is for backwards compatibility. Do we need to spam the log? I
would say dev_dbg().

Same for RX please.

	Andrew

Re: [PATCH net-next 2/2] dt-bindings: net: dsa: vsc73xx: add {rx,tx}-internal-delay-ps

[Andrew Lunn]

> +$defs:
> +  internal-delay-ps:
> +    description:
> +      Disable tunable delay lines using 0 ps, or enable them and select
> +      the phase between 1400 ps and 2000 ps in increments of 300 ps.
> +    enum:
> +      [0, 1400, 1700, 2000]

It would be nice to document what the default is if the property is
missing.

	Andrew