[PATCH net-next v4 0/2] net: lan743x: add RMII support for PCI11x1x

[PATCH net-next v4 0/2] net: lan743x: add RMII support for PCI11x1x

[Thangaraj Samynathan]

This series adds RMII interface support for the Microchip PCI11x1x
Ethernet controller.

The PCI11x1x device supports RMII as an alternative MAC-PHY interface,
selected via the STRAP_READ software strap register. Patch 1 reads the
RMII strap bits from this register and sets the is_rmii_en flag. Patch 2
uses this flag to configure the PHY interface mode, phylink supported
interfaces, and enables RMII in hardware via the RMII_CTL register.

Change Log:
===========
v3 -> v4:
  - Fix dev_dbg() in lan743x_mdiobus_init() to print "RMII operation"
    instead of "RGMII operation" when RMII is selected [Simon Horman]

v2 -> v3:
  - Update debug log to report selected interface (SGMII/RMII/RGMII)
    instead of only SGMII enable/disable state [patch 1/2]
  - Update commit message to document that EEE is disabled by setting
    lpi_capabilities = 0 [patch 2/2]

v1 -> v2:
  - Remove redundant mac_capabilities &= ~MAC_1000FD; phylink already
    handles capability reduction for RMII via phy_caps_from_interface()
    [patch 2/2]

Thangaraj Samynathan (2):
  net: lan743x: add RMII strap status detection for PCI11x1x
  net: lan743x: add support for RMII interface

 drivers/net/ethernet/microchip/lan743x_main.c | 34 ++++++++++++++++---
 drivers/net/ethernet/microchip/lan743x_main.h |  6 ++++
 2 files changed, 36 insertions(+), 4 deletions(-)

-- 
2.34.1

[PATCH net-next v4 1/2] net: lan743x: add RMII strap status detection for PCI11x1x

[Thangaraj Samynathan]

Extend pci11x1x_strap_get_status() to read the RMII strap bits from
the STRAP_READ register. The is_rmii_en flag is initialized to
false and updated based on the hardware strap only if SGMII is not
already enabled. This ensures correct interface identification during
adapter initialization.

Update the netif_dbg() to report the selected interface as SGMII,
RMII, or RGMII.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
---
 drivers/net/ethernet/microchip/lan743x_main.c | 12 ++++++++++--
 drivers/net/ethernet/microchip/lan743x_main.h |  3 +++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 1cdce35e1423..0798f3f1f435 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -42,6 +42,7 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 	u32 strap;
 	int ret;
 
+	adapter->is_rmii_en = false;
 	/* Timeout = 100 (i.e. 1 sec (10 msce * 100)) */
 	ret = lan743x_hs_syslock_acquire(adapter, 100);
 	if (ret < 0) {
@@ -73,8 +74,15 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 			adapter->is_sgmii_en = false;
 		}
 	}
-	netif_dbg(adapter, drv, adapter->netdev,
-		  "SGMII I/F %sable\n", adapter->is_sgmii_en ? "En" : "Dis");
+
+	if (!adapter->is_sgmii_en && strap & STRAP_READ_USE_RMII_EN_) {
+		if (strap & STRAP_READ_RMII_EN_)
+			adapter->is_rmii_en = true;
+	}
+
+	netif_dbg(adapter, drv, adapter->netdev, "Selected I/F: %s\n",
+		  adapter->is_sgmii_en ? "SGMII" :
+		  adapter->is_rmii_en  ? "RMII"  : "RGMII");
 }
 
 static bool is_pci11x1x_chip(struct lan743x_adapter *adapter)
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 1573c8f9c993..1f8d9294a6ef 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -36,7 +36,9 @@
 #define FPGA_SGMII_OP			BIT(24)
 
 #define STRAP_READ			(0x0C)
+#define STRAP_READ_USE_RMII_EN_		BIT(23)
 #define STRAP_READ_USE_SGMII_EN_	BIT(22)
+#define STRAP_READ_RMII_EN_		BIT(7)
 #define STRAP_READ_SGMII_EN_		BIT(6)
 #define STRAP_READ_SGMII_REFCLK_	BIT(5)
 #define STRAP_READ_SGMII_2_5G_		BIT(4)
@@ -1072,6 +1074,7 @@ struct lan743x_adapter {
 	struct lan743x_rx       rx[LAN743X_USED_RX_CHANNELS];
 	bool			is_pci11x1x;
 	bool			is_sgmii_en;
+	bool			is_rmii_en;
 	/* protect ethernet syslock */
 	spinlock_t		eth_syslock_spinlock;
 	bool			eth_syslock_en;
-- 
2.34.1

[PATCH net-next v4 2/2] net: lan743x: add support for RMII interface

[Thangaraj Samynathan]

Enable RMII interface in the lan743x driver for PHY and MAC
configuration.

- Select RMII interface in lan743x_phy_interface_select().
- Update phylink supported_interfaces and MAC capabilities.
- Enable RMII via RMII_CTL in lan743x_hardware_init().
- Define RMII_CTL register and enable bit in lan743x_main.h.

EEE is not supported with RMII on PCI11x1x: the hardware does not
implement LPI signaling over RMII. Clear RMII from lpi_interfaces to
prevent phylink from enabling EEE on this interface.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
---
 drivers/net/ethernet/microchip/lan743x_main.c | 22 +++++++++++++++++--
 drivers/net/ethernet/microchip/lan743x_main.h |  3 +++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 0798f3f1f435..75303b0e1df0 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1402,6 +1402,8 @@ static void lan743x_phy_interface_select(struct lan743x_adapter *adapter)
 
 	if (adapter->is_pci11x1x && adapter->is_sgmii_en)
 		adapter->phy_interface = PHY_INTERFACE_MODE_SGMII;
+	else if (adapter->is_pci11x1x && adapter->is_rmii_en)
+		adapter->phy_interface = PHY_INTERFACE_MODE_RMII;
 	else if (id_rev == ID_REV_ID_LAN7430_)
 		adapter->phy_interface = PHY_INTERFACE_MODE_GMII;
 	else if ((id_rev == ID_REV_ID_LAN7431_) && (data & MAC_CR_MII_EN_))
@@ -3190,6 +3192,12 @@ static int lan743x_phylink_create(struct lan743x_adapter *adapter)
 		__set_bit(PHY_INTERFACE_MODE_MII,
 			  adapter->phylink_config.supported_interfaces);
 		break;
+	case PHY_INTERFACE_MODE_RMII:
+		__set_bit(PHY_INTERFACE_MODE_RMII,
+			  adapter->phylink_config.supported_interfaces);
+		adapter->phylink_config.lpi_capabilities = 0;
+		break;
+
 	default:
 		phy_interface_set_rgmii(adapter->phylink_config.supported_interfaces);
 	}
@@ -3197,6 +3205,9 @@ static int lan743x_phylink_create(struct lan743x_adapter *adapter)
 	memcpy(adapter->phylink_config.lpi_interfaces,
 	       adapter->phylink_config.supported_interfaces,
 	       sizeof(adapter->phylink_config.lpi_interfaces));
+	if (adapter->phy_interface == PHY_INTERFACE_MODE_RMII)
+		__clear_bit(PHY_INTERFACE_MODE_RMII,
+			    adapter->phylink_config.lpi_interfaces);
 
 	pl = phylink_create(&adapter->phylink_config, NULL,
 			    adapter->phy_interface, &lan743x_phylink_mac_ops);
@@ -3541,6 +3552,7 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
 {
 	struct lan743x_tx *tx;
 	u32 sgmii_ctl;
+	u32 rmii_ctl;
 	int index;
 	int ret;
 
@@ -3562,6 +3574,11 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
 			sgmii_ctl |= SGMII_CTL_SGMII_POWER_DN_;
 		}
 		lan743x_csr_write(adapter, SGMII_CTL, sgmii_ctl);
+		if (adapter->is_rmii_en) {
+			rmii_ctl = lan743x_csr_read(adapter, RMII_CTL);
+			rmii_ctl |= RMII_CTL_RMII_ENABLE_;
+			lan743x_csr_write(adapter, RMII_CTL, rmii_ctl);
+		}
 	} else {
 		adapter->max_tx_channels = LAN743X_MAX_TX_CHANNELS;
 		adapter->used_tx_channels = LAN743X_USED_TX_CHANNELS;
@@ -3628,8 +3645,9 @@ static int lan743x_mdiobus_init(struct lan743x_adapter *adapter)
 			adapter->mdiobus->name = "lan743x-mdiobus-c45";
 			dev_dbg(&adapter->pdev->dev, "lan743x-mdiobus-c45\n");
 		} else {
-			dev_dbg(&adapter->pdev->dev, "RGMII operation\n");
-			// Only C22 support when RGMII I/F
+			dev_dbg(&adapter->pdev->dev, "%s operation\n",
+				adapter->is_rmii_en ? "RMII" : "RGMII");
+			// Only C22 support when RGMII/RMII I/F
 			adapter->mdiobus->read = lan743x_mdiobus_read_c22;
 			adapter->mdiobus->write = lan743x_mdiobus_write_c22;
 			adapter->mdiobus->name = "lan743x-mdiobus";
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 1f8d9294a6ef..d9495cf96b41 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -325,6 +325,9 @@
 #define MAC_WUCSR2_IPV6_TCPSYN_RCD_	BIT(5)
 #define MAC_WUCSR2_IPV4_TCPSYN_RCD_	BIT(4)
 
+#define RMII_CTL			(0x710)
+#define RMII_CTL_RMII_ENABLE_		BIT(0)
+
 #define SGMII_ACC			(0x720)
 #define SGMII_ACC_SGMII_BZY_		BIT(31)
 #define SGMII_ACC_SGMII_WR_		BIT(30)
-- 
2.34.1

Re: [PATCH net-next v4 0/2] net: lan743x: add RMII support for PCI11x1x

[Jakub Kicinski]

On Wed, 17 Jun 2026 11:02:39 +0530 Thangaraj Samynathan wrote:
> This series adds RMII interface support for the Microchip PCI11x1x
> Ethernet controller.
> 
> The PCI11x1x device supports RMII as an alternative MAC-PHY interface,
> selected via the STRAP_READ software strap register. Patch 1 reads the
> RMII strap bits from this register and sets the is_rmii_en flag. Patch 2
> uses this flag to configure the PHY interface mode, phylink supported
> interfaces, and enables RMII in hardware via the RMII_CTL register.

## Form letter - net-next-closed

We have already submitted our pull request with net-next material for v7.2,
and therefore net-next is closed for new drivers, features, code refactoring
and optimizations. We are currently accepting bug fixes only.

Please repost when net-next reopens after June 29th.

RFC patches sent for review only are obviously welcome at any time.

See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
-- 
pw-bot: defer
pv-bot: closed