realtek: add support for RTL8218E

ZyXEL XGS1250-12 Rev.B1 has RTL8218E compared to RTL8218D in Rev.A1
but both of them seem very similar and pin compatible. Therefore
they can share the same phy_driver callbacks.

PHY identifier is set based on the datasheet from
  https://github.com/plappermaul/realtek-doc/blob/main/RTL8218E-CG_Datasheet.pdf

Before:

[    2.120161] rtl83xx-switch switch@1b000000 lan1 (uninitialized): PHY [mdio-bus:00] driver [Generic PHY] (irq=POLL)
[    2.134581] rtl83xx-switch switch@1b000000 lan2 (uninitialized): PHY [mdio-bus:01] driver [Generic PHY] (irq=POLL)
[    2.149043] rtl83xx-switch switch@1b000000 lan3 (uninitialized): PHY [mdio-bus:02] driver [Generic PHY] (irq=POLL)
[    2.163498] rtl83xx-switch switch@1b000000 lan4 (uninitialized): PHY [mdio-bus:03] driver [Generic PHY] (irq=POLL)
[    2.177963] rtl83xx-switch switch@1b000000 lan5 (uninitialized): PHY [mdio-bus:04] driver [Generic PHY] (irq=POLL)
[    2.192435] rtl83xx-switch switch@1b000000 lan6 (uninitialized): PHY [mdio-bus:05] driver [Generic PHY] (irq=POLL)
[    2.207009] rtl83xx-switch switch@1b000000 lan7 (uninitialized): PHY [mdio-bus:06] driver [Generic PHY] (irq=POLL)
[    2.221474] rtl83xx-switch switch@1b000000 lan8 (uninitialized): PHY [mdio-bus:07] driver [Generic PHY] (irq=POLL)

After:

[    2.119165] rtl83xx-switch switch@1b000000 lan1 (uninitialized): PHY [mdio-bus:00] driver [REALTEK RTL8218E] (irq=POLL)
[    2.132880] rtl83xx-switch switch@1b000000 lan2 (uninitialized): PHY [mdio-bus:01] driver [REALTEK RTL8218E] (irq=POLL)
[    2.146727] rtl83xx-switch switch@1b000000 lan3 (uninitialized): PHY [mdio-bus:02] driver [REALTEK RTL8218E] (irq=POLL)
[    2.160580] rtl83xx-switch switch@1b000000 lan4 (uninitialized): PHY [mdio-bus:03] driver [REALTEK RTL8218E] (irq=POLL)
[    2.174367] rtl83xx-switch switch@1b000000 lan5 (uninitialized): PHY [mdio-bus:04] driver [REALTEK RTL8218E] (irq=POLL)
[    2.188270] rtl83xx-switch switch@1b000000 lan6 (uninitialized): PHY [mdio-bus:05] driver [REALTEK RTL8218E] (irq=POLL)
[    2.202140] rtl83xx-switch switch@1b000000 lan7 (uninitialized): PHY [mdio-bus:06] driver [REALTEK RTL8218E] (irq=POLL)
[    2.216047] rtl83xx-switch switch@1b000000 lan8 (uninitialized): PHY [mdio-bus:07] driver [REALTEK RTL8218E] (irq=POLL)

Based-on-patch-by: Antanas Bruzas <[email protected]>
Signed-off-by: Thomas Martitz <[email protected]>
Link: openwrt/openwrt#20068
Signed-off-by: Hauke Mehrtens <[email protected]>

Author: kugel-

target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c

@@ -3263,7 +3263,7 @@ static int rtl8218b_int_phy_probe(struct phy_device *phydev)
 	return 0;
 }
 
-static int rtl8218d_phy_probe(struct phy_device *phydev)
+static int rtl8218x_phy_probe(struct phy_device *phydev)
 {
 	int base_addr = phydev->mdio.addr & ~7;
 
@@ -3445,7 +3445,20 @@ static struct phy_driver rtl83xx_phy_driver[] = {
 		.name		= "REALTEK RTL8218D",
 		.config_init	= rtl821x_config_init,
 		.features	= PHY_GBIT_FEATURES,
-		.probe		= rtl8218d_phy_probe,
+		.probe		= rtl8218x_phy_probe,
+		.read_mmd	= rtl821x_read_mmd,
+		.read_page	= rtl821x_read_page,
+		.resume		= genphy_resume,
+		.suspend	= genphy_suspend,
+		.write_mmd	= rtl821x_write_mmd,
+		.write_page	= rtl821x_write_page,
+	},
+	{
+		PHY_ID_MATCH_EXACT(PHY_ID_RTL8218E),
+		.name		= "REALTEK RTL8218E",
+		.config_init	= rtl821x_config_init,
+		.features	= PHY_GBIT_FEATURES,
+		.probe		= rtl8218x_phy_probe,
 		.read_mmd	= rtl821x_read_mmd,
 		.read_page	= rtl821x_read_page,
 		.resume		= genphy_resume,

target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.h

@@ -23,6 +23,7 @@ struct __attribute__ ((__packed__)) fw_header {
 #define PHY_ID_RTL8218B_E			0x001cc980
 #define PHY_ID_RTL8214_OR_8218			0x001cc981
 #define PHY_ID_RTL8218D				0x001cc983
+#define PHY_ID_RTL8218E				0x001cc984
 #define PHY_ID_RTL8218B_I			0x001cca40
 #define PHY_ID_RTL8390_GENERIC			0x001ccab0
 #define PHY_ID_RTL8393_I			0x001c8393