[PATCH net-next V2 1/5] net: lan743x: Add SFP support check flag

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

Support for SFP in the PCI11x1x devices is indicated by the "is_sfp_support_en"
flag in the STRAP register. This register is loaded at power up from the
PCI11x1x EEPROM contents (which specify the board configuration).

Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@microchip.com>
---
Change List:
============
V1 -> V2:
  - Change variable name from "chip_rev" to "fpga_rev" 
V0 -> V1:
  - No changes

 drivers/net/ethernet/microchip/lan743x_main.c | 34 +++++++++++++++----
 drivers/net/ethernet/microchip/lan743x_main.h |  3 ++
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 4dc5adcda6a3..20a42a2c7b0e 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -28,9 +28,9 @@
 
 #define RFE_RD_FIFO_TH_3_DWORDS	0x3
 
-static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
+static int pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 {
-	u32 chip_rev;
+	u32 fpga_rev;
 	u32 cfg_load;
 	u32 hw_cfg;
 	u32 strap;
@@ -41,7 +41,7 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 	if (ret < 0) {
 		netif_err(adapter, drv, adapter->netdev,
 			  "Sys Lock acquire failed ret:%d\n", ret);
-		return;
+		return ret;
 	}
 
 	cfg_load = lan743x_csr_read(adapter, ETH_SYS_CONFIG_LOAD_STARTED_REG);
@@ -55,10 +55,15 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 			adapter->is_sgmii_en = true;
 		else
 			adapter->is_sgmii_en = false;
+
+		if ((strap & STRAP_SFP_USE_EN_) && (strap & STRAP_SFP_EN_))
+			adapter->is_sfp_support_en = true;
+		else
+			adapter->is_sfp_support_en = false;
 	} else {
-		chip_rev = lan743x_csr_read(adapter, FPGA_REV);
-		if (chip_rev) {
-			if (chip_rev & FPGA_SGMII_OP)
+		fpga_rev = lan743x_csr_read(adapter, FPGA_REV);
+		if (fpga_rev) {
+			if (fpga_rev & FPGA_SGMII_OP)
 				adapter->is_sgmii_en = true;
 			else
 				adapter->is_sgmii_en = false;
@@ -66,8 +71,21 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 			adapter->is_sgmii_en = false;
 		}
 	}
+
+	if (adapter->is_pci11x1x && !adapter->is_sgmii_en &&
+	    adapter->is_sfp_support_en) {
+		netif_err(adapter, drv, adapter->netdev,
+			  "Invalid eeprom cfg: sfp enabled with sgmii disabled");
+		return -EINVAL;
+	}
+
 	netif_dbg(adapter, drv, adapter->netdev,
 		  "SGMII I/F %sable\n", adapter->is_sgmii_en ? "En" : "Dis");
+	netif_dbg(adapter, drv, adapter->netdev,
+		  "SFP support %sable\n", adapter->is_sfp_support_en ?
+		  "En" : "Dis");
+
+	return 0;
 }
 
 static bool is_pci11x1x_chip(struct lan743x_adapter *adapter)
@@ -3470,7 +3488,9 @@ 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);
+		ret = pci11x1x_strap_get_status(adapter);
+		if (ret < 0)
+			return ret;
 		spin_lock_init(&adapter->eth_syslock_spinlock);
 		mutex_init(&adapter->sgmii_rw_lock);
 		pci11x1x_set_rfe_rd_fifo_threshold(adapter);
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 8ef897c114d3..f7e96496600b 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -36,6 +36,8 @@
 
 #define STRAP_READ			(0x0C)
 #define STRAP_READ_USE_SGMII_EN_	BIT(22)
+#define STRAP_SFP_USE_EN_		BIT(31)
+#define STRAP_SFP_EN_			BIT(15)
 #define STRAP_READ_SGMII_EN_		BIT(6)
 #define STRAP_READ_SGMII_REFCLK_	BIT(5)
 #define STRAP_READ_SGMII_2_5G_		BIT(4)
@@ -1079,6 +1081,7 @@ struct lan743x_adapter {
 	u8			max_tx_channels;
 	u8			used_tx_channels;
 	u8			max_vector_count;
+	bool			is_sfp_support_en;
 
 #define LAN743X_ADAPTER_FLAG_OTP		BIT(0)
 	u32			flags;
-- 
2.34.1