[PATCH v6 4/4] net: phy: realtek: add RTL8224 polarity support
From: Damien Dejean <hidden>
Date: 2026-02-07 09:25:59
Also in:
linux-devicetree, lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The RTL8224 has a register to configure the polarity of every pair of each port. It provides device designers more flexbility when wiring the chip. Unfortunately, the register is left in an unknown state after a reset. Thus on devices where the bootloader don't initialize it, the driver has to do it to detect and use a link. The MDI polarity swap can be set in the device tree using the property enet-phy-pair-polarity. The u32 value is a bitfield where bit[0..3] control the polarity of pairs A..D. Signed-off-by: Damien Dejean <redacted> --- drivers/net/phy/realtek/realtek_main.c | 45 +++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c
index 4f0c1b72f7e0..d15d3b41e5d1 100644
--- a/drivers/net/phy/realtek/realtek_main.c
+++ b/drivers/net/phy/realtek/realtek_main.c@@ -172,6 +172,7 @@ #define RTL8224_SRAM_RTCT_LEN(pair) (0x8028 + (pair) * 4) #define RTL8224_VND1_MDI_PAIR_SWAP 0xa90 +#define RTL8224_VND1_MDI_POLARITY_SWAP 0xa94 #define RTL8366RB_POWER_SAVE 0x15 #define RTL8366RB_POWER_SAVE_ON BIT(12)
@@ -1861,9 +1862,51 @@ static int rtl8224_mdi_config_order(struct phy_device *phydev) return ret; } +static int rtl8224_mdi_config_polarity(struct phy_device *phydev) +{ + struct device_node *np = phydev->mdio.dev.of_node; + u8 offset = (phydev->mdio.addr & 3) * 4; + u32 polarity = 0; + int ret, val; + + ret = of_property_read_u32(np, "enet-phy-pair-polarity", &polarity); + + /* Do nothing if the property is not present */ + if (ret == -EINVAL) + return 0; + + if (ret) + return ret; + + if (polarity & ~0xf) + return -EINVAL; + + phy_lock_mdio_bus(phydev); + val = __phy_package_read_mmd(phydev, 0, MDIO_MMD_VEND1, + RTL8224_VND1_MDI_POLARITY_SWAP); + if (val < 0) { + ret = val; + goto exit; + } + + val &= ~(0xf << offset); + val |= polarity << offset; + ret = __phy_package_write_mmd(phydev, 0, MDIO_MMD_VEND1, + RTL8224_VND1_MDI_POLARITY_SWAP, val); +exit: + phy_unlock_mdio_bus(phydev); + return ret; +} + static int rtl8224_config_init(struct phy_device *phydev) { - return rtl8224_mdi_config_order(phydev); + int ret; + + ret = rtl8224_mdi_config_order(phydev); + if (ret) + return ret; + + return rtl8224_mdi_config_polarity(phydev); } static int rtl8224_probe(struct phy_device *phydev)
--
2.47.3