Merge branch 'make-phy-output-rmii-reference-clock'

Wei Fang says:

====================
make PHY output RMII reference clock

The TJA11xx PHYs have the capability to provide 50MHz reference clock
in RMII mode and output on REF_CLK pin. Therefore, add the new property
"nxp,rmii-refclk-output" to support this feature. This property is only
available for PHYs which use nxp-c45-tja11xx driver, such as TJA1103,
TJA1104, TJA1120 and TJA1121.
====================

Link: https://patch.msgid.link/20241010061944.266966-1-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Documentation/devicetree/bindings/net/nxp,tja11xx.yaml

@@ -62,6 +62,22 @@ allOf:
             reference clock output when RMII mode enabled.
             Only supported on TJA1100 and TJA1101.
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - ethernet-phy-id001b.b010
+              - ethernet-phy-id001b.b013
+              - ethernet-phy-id001b.b030
+              - ethernet-phy-id001b.b031
+
+    then:
+      properties:
+        nxp,rmii-refclk-out:
+          type: boolean
+          description: Enable 50MHz RMII reference clock output on REF_CLK pin.
+
 patternProperties:
   "^ethernet-phy@[0-9a-f]+$":
     type: object

drivers/net/phy/nxp-c45-tja11xx.c

@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/mii.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/phy.h>
 #include <linux/processor.h>
 #include <linux/property.h>
@@ -185,6 +186,8 @@
 
 #define NXP_C45_SKB_CB(skb)	((struct nxp_c45_skb_cb *)(skb)->cb)
 
+#define TJA11XX_REVERSE_MODE		BIT(0)
+
 struct nxp_c45_phy;
 
 struct nxp_c45_skb_cb {
@@ -1510,6 +1513,8 @@ static int nxp_c45_get_delays(struct phy_device *phydev)
 
 static int nxp_c45_set_phy_mode(struct phy_device *phydev)
 {
+	struct nxp_c45_phy *priv = phydev->priv;
+	u16 basic_config;
 	int ret;
 
 	ret = phy_read_mmd(phydev, MDIO_MMD_VEND1, VEND1_ABILITIES);
@@ -1561,8 +1566,15 @@ static int nxp_c45_set_phy_mode(struct phy_device *phydev)
 			phydev_err(phydev, "rmii mode not supported\n");
 			return -EINVAL;
 		}
+
+		basic_config = MII_BASIC_CONFIG_RMII;
+
+		/* This is not PHY_INTERFACE_MODE_REVRMII */
+		if (priv->flags & TJA11XX_REVERSE_MODE)
+			basic_config |= MII_BASIC_CONFIG_REV;
+
 		phy_write_mmd(phydev, MDIO_MMD_VEND1, VEND1_MII_BASIC_CONFIG,
-			      MII_BASIC_CONFIG_RMII);
+			      basic_config);
 		break;
 	case PHY_INTERFACE_MODE_SGMII:
 		if (!(ret & SGMII_ABILITY)) {
@@ -1623,6 +1635,20 @@ static int nxp_c45_get_features(struct phy_device *phydev)
 	return genphy_c45_pma_read_abilities(phydev);
 }
 
+static int nxp_c45_parse_dt(struct phy_device *phydev)
+{
+	struct device_node *node = phydev->mdio.dev.of_node;
+	struct nxp_c45_phy *priv = phydev->priv;
+
+	if (!IS_ENABLED(CONFIG_OF_MDIO))
+		return 0;
+
+	if (of_property_read_bool(node, "nxp,rmii-refclk-out"))
+		priv->flags |= TJA11XX_REVERSE_MODE;
+
+	return 0;
+}
+
 static int nxp_c45_probe(struct phy_device *phydev)
 {
 	struct nxp_c45_phy *priv;
@@ -1642,6 +1668,8 @@ static int nxp_c45_probe(struct phy_device *phydev)
 
 	phydev->priv = priv;
 
+	nxp_c45_parse_dt(phydev);
+
 	mutex_init(&priv->ptp_lock);
 
 	phy_abilities = phy_read_mmd(phydev, MDIO_MMD_VEND1,

drivers/net/phy/nxp-c45-tja11xx.h

@@ -28,6 +28,7 @@ struct nxp_c45_phy {
 	int extts_index;
 	bool extts;
 	struct nxp_c45_macsec *macsec;
+	u32 flags;
 };
 
 #if IS_ENABLED(CONFIG_MACSEC)