From c1887257a81bf62f48178d3b9d31e23520d67b2c Mon Sep 17 00:00:00 2001 From: Damien Dejean Date: Wed, 18 Mar 2026 22:54:58 +0100 Subject: [PATCH 1/4] dt-bindings: net: ethernet-phy: add property enet-phy-pair-order Add property enet-phy-pair-order to the device tree bindings to define the pair order of the PHY. To simplify PCB design some manufacturers allow to wire the pairs in a reverse order, and change the order in software. The property can be set to 0 to force the normal pair order (ABCD), or 1 to force the reverse pair order (DCBA). Signed-off-by: Damien Dejean Reviewed-by: Rob Herring (Arm) Link: https://patch.msgid.link/20260318215502.106528-2-dam.dejean@gmail.com Signed-off-by: Jakub Kicinski --- Documentation/devicetree/bindings/net/ethernet-phy.yaml | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml index 58634fee9fc4..4a27547f7d7a 100644 --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml @@ -126,6 +126,12 @@ properties: e.g. wrong bootstrap configuration caused by issues in PCB layout design. + enet-phy-pair-order: + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 1] + description: + For normal (0) or reverse (1) order of the pairs (ABCD -> DCBA). + eee-broken-100tx: $ref: /schemas/types.yaml#/definitions/flag description: From 330296ea9e158758aa65631f5ec64aa74806b7e2 Mon Sep 17 00:00:00 2001 From: Damien Dejean Date: Wed, 18 Mar 2026 22:54:59 +0100 Subject: [PATCH 2/4] net: phy: realtek: add RTL8224 pair order support The RTL8224 has a register to configure a pair swap (from ABCD order to DCBA) providing PCB designers more flexbility when wiring the chip. The swap parameter has to be set correctly for each of the 4 ports before the chip can detect a link. After a reset, this register is (unfortunately) left in a random state, thus it has to be initialized. On most of the devices the bootloader does it once for all and we can rely on the value set, on some other it is not and the kernel has to do it. The MDI pair swap can be set in the device tree using the property enet-phy-pair-order. The property is set to 0 to keep the default order (ABCD), or 1 to reverse the pairs (DCBA). Signed-off-by: Damien Dejean Link: https://patch.msgid.link/20260318215502.106528-3-dam.dejean@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/phy/realtek/Kconfig | 1 + drivers/net/phy/realtek/realtek_main.c | 64 ++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) diff --git a/drivers/net/phy/realtek/Kconfig b/drivers/net/phy/realtek/Kconfig index b05c2a1e9024..a741b34d193e 100644 --- a/drivers/net/phy/realtek/Kconfig +++ b/drivers/net/phy/realtek/Kconfig @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only config REALTEK_PHY tristate "Realtek PHYs" + select PHY_PACKAGE help Currently supports RTL821x/RTL822x and fast ethernet PHYs diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c index 530b4e26d16e..63134e300c33 100644 --- a/drivers/net/phy/realtek/realtek_main.c +++ b/drivers/net/phy/realtek/realtek_main.c @@ -171,6 +171,8 @@ #define RTL8224_SRAM_RTCT_LEN(pair) (0x8028 + (pair) * 4) +#define RTL8224_VND1_MDI_PAIR_SWAP 0xa90 + #define RTL8366RB_POWER_SAVE 0x15 #define RTL8366RB_POWER_SAVE_ON BIT(12) @@ -1820,6 +1822,66 @@ static int rtl8224_cable_test_get_status(struct phy_device *phydev, bool *finish return rtl8224_cable_test_report(phydev, finished); } +static int rtl8224_package_modify_mmd(struct phy_device *phydev, int devad, + u32 regnum, u16 mask, u16 set) +{ + int val, ret; + + phy_lock_mdio_bus(phydev); + + val = __phy_package_read_mmd(phydev, 0, devad, regnum); + if (val < 0) { + ret = val; + goto exit; + } + + val &= ~mask; + val |= set; + + ret = __phy_package_write_mmd(phydev, 0, devad, regnum, val); + +exit: + phy_unlock_mdio_bus(phydev); + return ret; +} + +static int rtl8224_mdi_config_order(struct phy_device *phydev) +{ + struct device_node *np = phydev->mdio.dev.of_node; + u8 port_offset = phydev->mdio.addr & 3; + u32 order = 0; + int ret; + + ret = of_property_read_u32(np, "enet-phy-pair-order", &order); + + /* Do nothing in case the property is not present */ + if (ret == -EINVAL || ret == -ENOSYS) + return 0; + + if (ret) + return ret; + + if (order & ~1) + return -EINVAL; + + return rtl8224_package_modify_mmd(phydev, MDIO_MMD_VEND1, + RTL8224_VND1_MDI_PAIR_SWAP, + BIT(port_offset), + order ? BIT(port_offset) : 0); +} + +static int rtl8224_config_init(struct phy_device *phydev) +{ + return rtl8224_mdi_config_order(phydev); +} + +static int rtl8224_probe(struct phy_device *phydev) +{ + /* Chip exposes 4 ports, join all of them in the same package */ + return devm_phy_package_join(&phydev->mdio.dev, phydev, + phydev->mdio.addr & ~3, 0); +} + static bool rtlgen_supports_2_5gbps(struct phy_device *phydev) { int val; @@ -2395,6 +2457,8 @@ static struct phy_driver realtek_drvs[] = { PHY_ID_MATCH_EXACT(0x001ccad0), .name = "RTL8224 2.5Gbps PHY", .flags = PHY_POLL_CABLE_TEST, + .probe = rtl8224_probe, + .config_init = rtl8224_config_init, .get_features = rtl822x_c45_get_features, .config_aneg = rtl822x_c45_config_aneg, .read_status = rtl822x_c45_read_status, From 58ffb5910f32e5b387d4af31ee21851c40eb31b5 Mon Sep 17 00:00:00 2001 From: Damien Dejean Date: Wed, 18 Mar 2026 22:55:00 +0100 Subject: [PATCH 3/4] dt-bindings: net: ethernet-phy: add property enet-phy-pair-polarity Add the property enet-phy-pair-polarity to describe the polarity of the PHY pairs. To ease PCB designs some manufacturers allow to wire the pairs with a reverse polarity and provide a way to configure it. The property 'enet-phy-pair-polarity' sets the polarity of each pair. Bit 0 to 3 configure the polarity or pairs A to D, if set to 1 the polarity is reversed for this pair. Signed-off-by: Damien Dejean Reviewed-by: Rob Herring (Arm) Link: https://patch.msgid.link/20260318215502.106528-4-dam.dejean@gmail.com Signed-off-by: Jakub Kicinski --- Documentation/devicetree/bindings/net/ethernet-phy.yaml | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml index 4a27547f7d7a..21a1a63506f0 100644 --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml @@ -132,6 +132,14 @@ properties: description: For normal (0) or reverse (1) order of the pairs (ABCD -> DCBA). + enet-phy-pair-polarity: + $ref: /schemas/types.yaml#/definitions/uint32 + maximum: 0xf + description: + A bitmap to describe pair polarity swap. Bit 0 to swap polarity of pair A, + bit 1 to swap polarity of pair B, bit 2 to swap polarity of pair C and bit + 3 to swap polarity of pair D. + eee-broken-100tx: $ref: /schemas/types.yaml#/definitions/flag description: From beed9c0e9b53c98bc66d28d46fbe38c347e9aa74 Mon Sep 17 00:00:00 2001 From: Damien Dejean Date: Wed, 18 Mar 2026 22:55:01 +0100 Subject: [PATCH 4/4] net: phy: realtek: add RTL8224 polarity support 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 Link: https://patch.msgid.link/20260318215502.106528-5-dam.dejean@gmail.com Signed-off-by: Jakub Kicinski --- drivers/net/phy/realtek/realtek_main.c | 34 +++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c index 63134e300c33..023e47ad605b 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) @@ -1870,9 +1871,40 @@ static int rtl8224_mdi_config_order(struct phy_device *phydev) order ? BIT(port_offset) : 0); } +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; + + ret = of_property_read_u32(np, "enet-phy-pair-polarity", &polarity); + + /* Do nothing if the property is not present */ + if (ret == -EINVAL || ret == -ENOSYS) + return 0; + + if (ret) + return ret; + + if (polarity & ~0xf) + return -EINVAL; + + return rtl8224_package_modify_mmd(phydev, MDIO_MMD_VEND1, + RTL8224_VND1_MDI_POLARITY_SWAP, + 0xf << offset, + polarity << offset); +} + 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)