net: phy: adin: add adi,phy-mode-override property

Override phy-mode property for adin. This is useful when a single
device tree supports an adin PHY (e.g. ADIN1300) or another PHY
(e.g. AR8033) at the same address, but they require different phy-modes.

Signed-off-by: Nate Drude <nate.d@variscite.com>

Documentation/devicetree/bindings/net/adi,adin.yaml

@@ -36,6 +36,12 @@ properties:
     enum: [ 4, 8, 12, 16, 20, 24 ]
     default: 8
 
+  adi,phy-mode-override:
+    description: |
+      Override phy-mode property for adin. This is useful when a single device tree
+      supports an adin PHY (e.g. ADIN1300) or another PHY (e.g. AR8033) at the same
+      address, but they require different phy-modes.
+
 examples:
   - |
     ethernet {
@@ -49,6 +55,7 @@ examples:
 
             adi,rx-internal-delay-ps = <1800>;
             adi,tx-internal-delay-ps = <2200>;
+            adi,phy-mode-override = "rgmii-id";
         };
     };
   - |

drivers/net/phy/adin.c

@@ -13,6 +13,7 @@
 #include <linux/mii.h>
 #include <linux/phy.h>
 #include <linux/property.h>
+#include <linux/of.h>
 
 #define PHY_ID_ADIN1200				0x0283bc20
 #define PHY_ID_ADIN1300				0x0283bc30
@@ -180,6 +181,39 @@ struct adin_priv {
 	u64			stats[ARRAY_SIZE(adin_hw_stats)];
 };
 
+/**
+ * adin_get_phy_mode_override - Get phy-mode override for adin PHY
+ *
+ * The function gets phy-mode string from property 'adi,phy-mode-override'
+ * and return its index in phy_modes table, or errno in error case.
+ */
+int adin_get_phy_mode_override(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct device_node *of_node = dev->of_node;
+	const char *phy_mode_override;
+	const char *prop_phy_mode_override = "adi,phy-mode-override";
+	int err, i;
+
+	err = of_property_read_string(of_node, prop_phy_mode_override,
+				      &phy_mode_override);
+	if (err < 0)
+		return err;
+
+	phydev_info(phydev,
+		    "%s = '%s'\n", prop_phy_mode_override, phy_mode_override);
+
+	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
+		if (!strcasecmp(phy_mode_override, phy_modes(i)))
+			return i;
+
+	phydev_err(phydev,
+		   "%s = '%s' is not valid\n",
+		   prop_phy_mode_override, phy_mode_override);
+
+	return -ENODEV;
+}
+
 static int adin_lookup_reg_value(const struct adin_cfg_reg_map *tbl, int cfg)
 {
 	size_t i;
@@ -219,6 +253,11 @@ static int adin_config_rgmii_mode(struct phy_device *phydev)
 {
 	u32 val;
 	int reg;
+	int phy_mode_override = adin_get_phy_mode_override(phydev);
+
+	if (phy_mode_override >= 0) {
+		phydev->interface = (phy_interface_t) phy_mode_override;
+	}
 
 	if (!phy_interface_is_rgmii(phydev))
 		return phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1,