[PATCH net-next v3 1/2] net: lan743x: add RMII strap status detection for PCI11x1x

[Thangaraj Samynathan <thangaraj.s@microchip.com>]

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.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
---
Changes in v3:
  - Update debug log to report selected interface (SGMII/RMII/RGMII)
    instead of only SGMII enable/disable state

 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