[PATCH net-next V1 4/5] net: lan743x: Add support for SGMII interface

[Raju Lakkaraju <Raju.Lakkaraju@microchip.com>]

This change facilitates the selection between SGMII and (R)GIII
interfaces

Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@microchip.com>
---
Changes:
 V1: 1. Replace "netif_info" with "netif_dbg"
     2. Add strap check for ASIC and FPGA device configuration
     3. Based on review comments, optimise the code

 drivers/net/ethernet/microchip/lan743x_main.c | 48 +++++++++++++++++++
 drivers/net/ethernet/microchip/lan743x_main.h | 17 +++++++
 2 files changed, 65 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 814d825e3deb..8b0890aa66fa 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -18,6 +18,34 @@
 #include "lan743x_main.h"
 #include "lan743x_ethtool.h"
 
+static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
+{
+	u32 chip_rev;
+	u32 strap;
+
+	strap = lan743x_csr_read(adapter, STRAP_READ);
+	if (strap & STRAP_READ_USE_SGMII_EN_) {
+		if (strap & STRAP_READ_SGMII_EN_)
+			adapter->is_sgmii_en = true;
+		else
+			adapter->is_sgmii_en = false;
+		netif_dbg(adapter, drv, adapter->netdev,
+			  "STRAP_READ: 0x%08X\n", strap);
+	} else {
+		chip_rev = lan743x_csr_read(adapter, FPGA_REV);
+		if (chip_rev) {
+			if (chip_rev & FPGA_SGMII_OP)
+				adapter->is_sgmii_en = true;
+			else
+				adapter->is_sgmii_en = false;
+			netif_dbg(adapter, drv, adapter->netdev,
+				  "FPGA_REV: 0x%08X\n", chip_rev);
+		} else {
+			adapter->is_sgmii_en = false;
+		}
+	}
+}
+
 static bool is_pci11x1x_chip(struct lan743x_adapter *adapter)
 {
 	struct lan743x_csr *csr = &adapter->csr;
@@ -2744,6 +2772,7 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
 		adapter->max_tx_channels = PCI11X1X_MAX_TX_CHANNELS;
 		adapter->used_tx_channels = PCI11X1X_USED_TX_CHANNELS;
 		adapter->max_vector_count = PCI11X1X_MAX_VECTOR_COUNT;
+		pci11x1x_strap_get_status(adapter);
 	} else {
 		adapter->max_tx_channels = LAN743X_MAX_TX_CHANNELS;
 		adapter->used_tx_channels = LAN743X_USED_TX_CHANNELS;
@@ -2792,6 +2821,7 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
 
 static int lan743x_mdiobus_init(struct lan743x_adapter *adapter)
 {
+	u32 sgmii_ctl;
 	int ret;
 
 	adapter->mdiobus = devm_mdiobus_alloc(&adapter->pdev->dev);
@@ -2801,6 +2831,24 @@ static int lan743x_mdiobus_init(struct lan743x_adapter *adapter)
 	}
 
 	adapter->mdiobus->priv = (void *)adapter;
+	if (adapter->is_pci11x1x) {
+		if (adapter->is_sgmii_en) {
+			sgmii_ctl = lan743x_csr_read(adapter, SGMII_CTL);
+			sgmii_ctl |= SGMII_CTL_SGMII_ENABLE_;
+			sgmii_ctl &= ~SGMII_CTL_SGMII_POWER_DN_;
+			lan743x_csr_write(adapter, SGMII_CTL, sgmii_ctl);
+			netif_dbg(adapter, drv, adapter->netdev,
+				  "SGMII operation\n");
+		} else {
+			sgmii_ctl = lan743x_csr_read(adapter, SGMII_CTL);
+			sgmii_ctl &= ~SGMII_CTL_SGMII_ENABLE_;
+			sgmii_ctl |= SGMII_CTL_SGMII_POWER_DN_;
+			lan743x_csr_write(adapter, SGMII_CTL, sgmii_ctl);
+			netif_dbg(adapter, drv, adapter->netdev,
+					  "(R)GMII operation\n");
+		}
+	}
+
 	adapter->mdiobus->read = lan743x_mdiobus_read;
 	adapter->mdiobus->write = lan743x_mdiobus_write;
 	adapter->mdiobus->name = "lan743x-mdiobus";
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 9a3ac9df4209..7c387ca2d25c 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -30,6 +30,17 @@
 #define FPGA_REV			(0x04)
 #define FPGA_REV_GET_MINOR_(fpga_rev)	(((fpga_rev) >> 8) & 0x000000FF)
 #define FPGA_REV_GET_MAJOR_(fpga_rev)	((fpga_rev) & 0x000000FF)
+#define FPGA_SGMII_OP			BIT(24)
+
+#define STRAP_READ			(0x0C)
+#define STRAP_READ_USE_SGMII_EN_	BIT(22)
+#define STRAP_READ_SGMII_EN_		BIT(6)
+#define STRAP_READ_SGMII_REFCLK_	BIT(5)
+#define STRAP_READ_SGMII_2_5G_		BIT(4)
+#define STRAP_READ_BASE_X_		BIT(3)
+#define STRAP_READ_RGMII_TXC_DELAY_EN_	BIT(2)
+#define STRAP_READ_RGMII_RXC_DELAY_EN_	BIT(1)
+#define STRAP_READ_ADV_PM_DISABLE_	BIT(0)
 
 #define HW_CFG					(0x010)
 #define HW_CFG_RELOAD_TYPE_ALL_			(0x00000FC0)
@@ -219,6 +230,11 @@
 
 #define MAC_WUCSR2			(0x600)
 
+#define SGMII_CTL			(0x728)
+#define SGMII_CTL_SGMII_ENABLE_		BIT(31)
+#define SGMII_CTL_LINK_STATUS_SOURCE_	BIT(8)
+#define SGMII_CTL_SGMII_POWER_DN_	BIT(1)
+
 #define INT_STS				(0x780)
 #define INT_BIT_DMA_RX_(channel)	BIT(24 + (channel))
 #define INT_BIT_ALL_RX_			(0x0F000000)
@@ -739,6 +755,7 @@ struct lan743x_adapter {
 	struct lan743x_tx       tx[PCI11X1X_USED_TX_CHANNELS];
 	struct lan743x_rx       rx[LAN743X_USED_RX_CHANNELS];
 	bool			is_pci11x1x;
+	bool			is_sgmii_en;
 	u8			max_tx_channels;
 	u8			used_tx_channels;
 	u8			max_vector_count;
-- 
2.25.1