[PATCH net-next v2 0/2] net: lan743x: add RMII support for PCI11x1x

[PATCH net-next v2 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:
===========
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 | 24 +++++++++++++++++++
 drivers/net/ethernet/microchip/lan743x_main.h |  6 +++++
 2 files changed, 30 insertions(+)

-- 
2.34.1

[PATCH net-next v2 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.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
---
 drivers/net/ethernet/microchip/lan743x_main.c | 7 +++++++
 drivers/net/ethernet/microchip/lan743x_main.h | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index f3332417162e..7d6ffaf13b5e 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) {
@@ -73,6 +74,12 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
 			adapter->is_sgmii_en = false;
 		}
 	}
+
+	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,
 		  "SGMII I/F %sable\n", adapter->is_sgmii_en ? "En" : "Dis");
 }
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 160d94a7cee6..1d7d37456553 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)
@@ -1071,6 +1073,7 @@ 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 v2 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.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
---
 drivers/net/ethernet/microchip/lan743x_main.c | 17 +++++++++++++++++
 drivers/net/ethernet/microchip/lan743x_main.h |  3 +++
 2 files changed, 20 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 7d6ffaf13b5e..1c0484c4705d 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1370,6 +1370,8 @@ 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_))
@@ -3158,6 +3160,12 @@ 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);
 	}
@@ -3165,6 +3173,9 @@ 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);
@@ -3509,6 +3520,7 @@ static int lan743x_hardware_init(struct lan743x_adapter *adapter,
 {
 	struct lan743x_tx *tx;
 	u32 sgmii_ctl;
+	u32 rmii_ctl;
 	int index;
 	int ret;
 
@@ -3530,6 +3542,11 @@ 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;
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 1d7d37456553..03f3727ed8f7 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -324,6 +324,9 @@
 #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 v2 1/2] net: lan743x: add RMII strap status detection for PCI11x1x

[Andrew Lunn]

> +	if (!adapter->is_sgmii_en && strap & STRAP_READ_USE_RMII_EN_) {
> +		if (strap & STRAP_READ_RMII_EN_)
> +			adapter->is_rmii_en = true;
> +	}

What does it mean when both SGMII and RMII is strapped? What if
neither is strapped?

> +
>  	netif_dbg(adapter, drv, adapter->netdev,
>  		  "SGMII I/F %sable\n", adapter->is_sgmii_en ? "En" : "Dis");

Since there is a netif_dbg() for sgmii, maybe add one for rmii, so the
code is somewhat symmetrical?

>  	struct lan743x_rx       rx[LAN743X_USED_RX_CHANNELS];
>  	bool			is_pci11x1x;
>  	bool			is_sgmii_en;
> +	bool			is_rmii_en;

Are there other strapping bits? Are we going to get is_gmii_en, and
is_rgmii_en?

Does a collection of bools make sense, when the interface modes are
typically mutually exclusive at the hardware level? Would an enum be
better? Or why not phy_interface_t ?

	Andrew