Different versions of NETC switches have different numbers of ports and
MAC capabilities, so add .phylink_get_caps() to struct netc_switch_info,
so that each version of the NETC switch can implement its own callback
to obtain MAC capabilities. In addition, related interfaces of struct
phylink_mac_ops are added, such as .mac_config(), .mac_link_up(), and
.mac_link_down().

Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/dsa/netc/netc_main.c      | 212 ++++++++++++++++++++++++++
 drivers/net/dsa/netc/netc_platform.c  |  40 +++++
 drivers/net/dsa/netc/netc_switch.h    |   4 +
 drivers/net/dsa/netc/netc_switch_hw.h |  25 +++
 4 files changed, 281 insertions(+)

diff --git a/drivers/net/dsa/netc/netc_main.c b/drivers/net/dsa/netc/netc_main.c
index 5828fd3e342e..e2d88496f5f3 100644
--- a/drivers/net/dsa/netc/netc_main.c
+++ b/drivers/net/dsa/netc/netc_main.c
@@ -569,10 +569,221 @@ static void netc_switch_get_ip_revision(struct netc_switch *priv)
 	priv->revision = val & IPBRR0_IP_REV;
 }
 
+static void netc_phylink_get_caps(struct dsa_switch *ds, int port,
+				  struct phylink_config *config)
+{
+	struct netc_switch *priv = ds->priv;
+
+	priv->info->phylink_get_caps(port, config);
+}
+
+static void netc_port_set_mac_mode(struct netc_port *np,
+				   unsigned int mode,
+				   phy_interface_t phy_mode)
+{
+	u32 mask = PM_IF_MODE_IFMODE | PM_IF_MODE_REVMII | PM_IF_MODE_ENA;
+	u32 val = 0;
+
+	switch (phy_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		val |= IFMODE_RGMII;
+		/* Enable auto-negotiation for the MAC if its
+		 * RGMII interface supports In-Band status.
+		 */
+		if (phylink_autoneg_inband(mode))
+			val |= PM_IF_MODE_ENA;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		val |= IFMODE_RMII;
+		break;
+	case PHY_INTERFACE_MODE_REVMII:
+		val |= PM_IF_MODE_REVMII;
+		fallthrough;
+	case PHY_INTERFACE_MODE_MII:
+		val |= IFMODE_MII;
+		break;
+	case PHY_INTERFACE_MODE_SGMII:
+	case PHY_INTERFACE_MODE_2500BASEX:
+		val |= IFMODE_SGMII;
+		break;
+	default:
+		break;
+	}
+
+	netc_mac_port_rmw(np, NETC_PM_IF_MODE(0), mask, val);
+}
+
+static void netc_mac_config(struct phylink_config *config, unsigned int mode,
+			    const struct phylink_link_state *state)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+
+	netc_port_set_mac_mode(NETC_PORT(dp->ds, dp->index), mode,
+			       state->interface);
+}
+
+static void netc_port_set_speed(struct netc_port *np, int speed)
+{
+	netc_port_rmw(np, NETC_PCR, PCR_PSPEED, PSPEED_SET_VAL(speed));
+}
+
+/* If the RGMII device does not support the In-Band Status (IBS), we need
+ * the MAC driver to get the link speed and duplex mode from the PHY driver.
+ * The MAC driver then sets the MAC for the correct speed and duplex mode
+ * to match the PHY. The PHY driver gets the link status and speed and duplex
+ * information from the PHY via the MDIO/MDC interface.
+ */
+static void netc_port_force_set_rgmii_mac(struct netc_port *np,
+					  int speed, int duplex)
+{
+	u32 mask, val;
+
+	mask = PM_IF_MODE_ENA | PM_IF_MODE_SSP | PM_IF_MODE_HD |
+	       PM_IF_MODE_M10 | PM_IF_MODE_REVMII;
+
+	switch (speed) {
+	default:
+	case SPEED_1000:
+		val = FIELD_PREP(PM_IF_MODE_SSP, SSP_1G);
+		break;
+	case SPEED_100:
+		val = FIELD_PREP(PM_IF_MODE_SSP, SSP_100M);
+		break;
+	case SPEED_10:
+		val = FIELD_PREP(PM_IF_MODE_SSP, SSP_10M);
+		break;
+	}
+
+	if (duplex != DUPLEX_FULL)
+		val |= PM_IF_MODE_HD;
+
+	netc_mac_port_rmw(np, NETC_PM_IF_MODE(0), mask, val);
+}
+
+static void netc_port_set_rmii_mii_mac(struct netc_port *np,
+				       int speed, int duplex)
+{
+	u32 mask, val = 0;
+
+	mask = PM_IF_MODE_ENA | PM_IF_MODE_SSP | PM_IF_MODE_HD |
+	       PM_IF_MODE_M10;
+
+	if (speed == SPEED_10)
+		val |= PM_IF_MODE_M10;
+
+	if (duplex != DUPLEX_FULL)
+		val |= PM_IF_MODE_HD;
+
+	netc_mac_port_rmw(np, NETC_PM_IF_MODE(0), mask, val);
+}
+
+static void netc_port_set_hd_flow_control(struct netc_port *np, bool en)
+{
+	if (!np->caps.half_duplex)
+		return;
+
+	/* The HD_FCEN is used in conjunction with the PM_HD_FLOW_CTRL
+	 * register, which has a default value, so currently we do not
+	 * set it in the driver. The half duplex flow control works by
+	 * the backpressure, and the backpressure is essentially just
+	 * a long preamble transmitted on the link intended to create
+	 * a collision and get the half duplex link partner to defer.
+	 */
+	netc_mac_port_rmw(np, NETC_PM_CMD_CFG(0), PM_CMD_CFG_HD_FCEN,
+			  en ? PM_CMD_CFG_HD_FCEN : 0);
+}
+
+static void netc_port_mac_rx_enable(struct netc_port *np)
+{
+	netc_port_rmw(np, NETC_POR, PCR_RXDIS, 0);
+	netc_mac_port_rmw(np, NETC_PM_CMD_CFG(0), PM_CMD_CFG_RX_EN,
+			  PM_CMD_CFG_RX_EN);
+}
+
+static void netc_port_wait_rx_empty(struct netc_port *np, int mac)
+{
+	u32 val;
+
+	if (read_poll_timeout(netc_port_rd, val, val & PM_IEVENT_RX_EMPTY,
+			      100, 10000, false, np, NETC_PM_IEVENT(mac)))
+		dev_warn(np->switch_priv->dev,
+			 "MAC %d of swp%d RX is not empty\n", mac,
+			 np->dp->index);
+}
+
+static void netc_port_mac_rx_graceful_stop(struct netc_port *np)
+{
+	u32 val;
+
+	if (is_netc_pseudo_port(np))
+		goto check_rx_busy;
+
+	if (np->caps.pmac) {
+		netc_port_rmw(np, NETC_PM_CMD_CFG(1), PM_CMD_CFG_RX_EN, 0);
+		netc_port_wait_rx_empty(np, 1);
+	}
+
+	netc_port_rmw(np, NETC_PM_CMD_CFG(0), PM_CMD_CFG_RX_EN, 0);
+	netc_port_wait_rx_empty(np, 0);
+
+check_rx_busy:
+	if (read_poll_timeout(netc_port_rd, val, !(val & PSR_RX_BUSY),
+			      100, 10000, false, np, NETC_PSR))
+		dev_warn(np->switch_priv->dev, "swp%d RX is busy\n",
+			 np->dp->index);
+
+	netc_port_rmw(np, NETC_POR, PCR_RXDIS, PCR_RXDIS);
+}
+
+static void netc_mac_link_up(struct phylink_config *config,
+			     struct phy_device *phy, unsigned int mode,
+			     phy_interface_t interface, int speed,
+			     int duplex, bool tx_pause, bool rx_pause)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct netc_port *np;
+
+	np = NETC_PORT(dp->ds, dp->index);
+	netc_port_set_speed(np, speed);
+
+	if (phy_interface_mode_is_rgmii(interface) &&
+	    !phylink_autoneg_inband(mode)) {
+		netc_port_force_set_rgmii_mac(np, speed, duplex);
+	}
+
+	if (interface == PHY_INTERFACE_MODE_RMII ||
+	    interface == PHY_INTERFACE_MODE_REVMII ||
+	    interface == PHY_INTERFACE_MODE_MII) {
+		netc_port_set_rmii_mii_mac(np, speed, duplex);
+	}
+
+	netc_port_set_hd_flow_control(np, duplex == DUPLEX_HALF);
+	netc_port_mac_rx_enable(np);
+}
+
+static void netc_mac_link_down(struct phylink_config *config,
+			       unsigned int mode,
+			       phy_interface_t interface)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+
+	netc_port_mac_rx_graceful_stop(NETC_PORT(dp->ds, dp->index));
+}
+
+static const struct phylink_mac_ops netc_phylink_mac_ops = {
+	.mac_config		= netc_mac_config,
+	.mac_link_up		= netc_mac_link_up,
+	.mac_link_down		= netc_mac_link_down,
+};
+
 static const struct dsa_switch_ops netc_switch_ops = {
 	.get_tag_protocol		= netc_get_tag_protocol,
 	.setup				= netc_setup,
 	.teardown			= netc_teardown,
+	.phylink_get_caps		= netc_phylink_get_caps,
 };
 
 static int netc_switch_probe(struct pci_dev *pdev,
@@ -613,6 +824,7 @@ static int netc_switch_probe(struct pci_dev *pdev,
 	ds->num_ports = priv->info->num_ports;
 	ds->num_tx_queues = NETC_TC_NUM;
 	ds->ops = &netc_switch_ops;
+	ds->phylink_mac_ops = &netc_phylink_mac_ops;
 	ds->priv = priv;
 
 	priv->ds = ds;
diff --git a/drivers/net/dsa/netc/netc_platform.c b/drivers/net/dsa/netc/netc_platform.c
index abd599ea9c8d..8d3fb5151902 100644
--- a/drivers/net/dsa/netc/netc_platform.c
+++ b/drivers/net/dsa/netc/netc_platform.c
@@ -11,8 +11,48 @@ struct netc_switch_platform {
 	const struct netc_switch_info *info;
 };
 
+static void imx94_switch_phylink_get_caps(int port,
+					  struct phylink_config *config)
+{
+	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
+				   MAC_1000FD;
+
+	switch (port) {
+	case 0 ... 1:
+		__set_bit(PHY_INTERFACE_MODE_SGMII,
+			  config->supported_interfaces);
+		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
+			  config->supported_interfaces);
+		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
+			  config->supported_interfaces);
+		config->mac_capabilities |= MAC_2500FD;
+		fallthrough;
+	case 2:
+		config->mac_capabilities |= MAC_10 | MAC_100;
+		__set_bit(PHY_INTERFACE_MODE_MII,
+			  config->supported_interfaces);
+		__set_bit(PHY_INTERFACE_MODE_RMII,
+			  config->supported_interfaces);
+		if (port == 2)
+			__set_bit(PHY_INTERFACE_MODE_REVMII,
+				  config->supported_interfaces);
+
+		phy_interface_set_rgmii(config->supported_interfaces);
+		break;
+	case 3: /* CPU port */
+		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
+			  config->supported_interfaces);
+		config->mac_capabilities |= MAC_10FD | MAC_100FD |
+					    MAC_2500FD;
+		break;
+	default:
+		break;
+	}
+}
+
 static const struct netc_switch_info imx94_info = {
 	.num_ports = 4,
+	.phylink_get_caps = imx94_switch_phylink_get_caps,
 };
 
 static const struct netc_switch_platform netc_platforms[] = {
diff --git a/drivers/net/dsa/netc/netc_switch.h b/drivers/net/dsa/netc/netc_switch.h
index dac19bfba02b..eb65c36ecead 100644
--- a/drivers/net/dsa/netc/netc_switch.h
+++ b/drivers/net/dsa/netc/netc_switch.h
@@ -34,6 +34,7 @@ struct netc_switch;
 
 struct netc_switch_info {
 	u32 num_ports;
+	void (*phylink_get_caps)(int port, struct phylink_config *config);
 };
 
 struct netc_port_caps {
@@ -70,6 +71,9 @@ struct netc_switch {
 	struct ntmp_user ntmp;
 };
 
+#define NETC_PRIV(ds)			((struct netc_switch *)((ds)->priv))
+#define NETC_PORT(ds, port_id)		(NETC_PRIV(ds)->ports[(port_id)])
+
 /* Write/Read Switch base registers */
 #define netc_base_rd(r, o)		netc_read((r)->base + (o))
 #define netc_base_wr(r, o, v)		netc_write((r)->base + (o), v)
diff --git a/drivers/net/dsa/netc/netc_switch_hw.h b/drivers/net/dsa/netc/netc_switch_hw.h
index 03b49857c854..6d7758631e61 100644
--- a/drivers/net/dsa/netc/netc_switch_hw.h
+++ b/drivers/net/dsa/netc/netc_switch_hw.h
@@ -71,6 +71,10 @@
 #define  PCR_TXDIS			BIT(0)
 #define  PCR_RXDIS			BIT(1)
 
+#define NETC_PSR			0x104
+#define  PSR_TX_BUSY			BIT(0)
+#define  PSR_RX_BUSY			BIT(1)
+
 #define NETC_PTCTMSDUR(a)		(0x208 + (a) * 0x20)
 #define  PTCTMSDUR_MAXSDU		GENMASK(15, 0)
 #define  PTCTMSDUR_SDU_TYPE		GENMASK(17, 16)
@@ -145,6 +149,27 @@ enum netc_mfo {
 #define NETC_PM_MAXFRM(a)		(0x1014 + (a) * 0x400)
 #define  PM_MAXFRAM			GENMASK(15, 0)
 
+#define NETC_PM_IEVENT(a)		(0x1040 + (a) * 0x400)
+#define  PM_IEVENT_RX_EMPTY		BIT(6)
+
+#define NETC_PM_IF_MODE(a)		(0x1300 + (a) * 0x400)
+#define  PM_IF_MODE_IFMODE		GENMASK(2, 0)
+#define   IFMODE_MII			1
+#define   IFMODE_RMII			3
+#define   IFMODE_RGMII			4
+#define   IFMODE_SGMII			5
+#define  PM_IF_MODE_REVMII		BIT(3)
+#define  PM_IF_MODE_M10			BIT(4)
+#define  PM_IF_MODE_HD			BIT(6)
+#define  PM_IF_MODE_RGMII_RX_SKW	BIT(10)
+#define  PM_IF_MODE_RGMII_TX_SKW	BIT(11)
+#define  PM_IF_MODE_CLK_STOP		BIT(12)
+#define  PM_IF_MODE_SSP			GENMASK(14, 13)
+#define   SSP_100M			0
+#define   SSP_10M			1
+#define   SSP_1G			2
+#define  PM_IF_MODE_ENA			BIT(15)
+
 #define NETC_PEMDIOCR			0x1c00
 #define NETC_EMDIO_BASE			NETC_PEMDIOCR
 
-- 
2.34.1

On Mon, Mar 23, 2026 at 02:07:49PM +0800, Wei Fang wrote:
> +static void netc_port_set_mac_mode(struct netc_port *np,
> +				   unsigned int mode,
> +				   phy_interface_t phy_mode)
> +{
> +	u32 mask = PM_IF_MODE_IFMODE | PM_IF_MODE_REVMII | PM_IF_MODE_ENA;
> +	u32 val = 0;
> +
> +	switch (phy_mode) {
> +	case PHY_INTERFACE_MODE_RGMII:
> +	case PHY_INTERFACE_MODE_RGMII_ID:
> +	case PHY_INTERFACE_MODE_RGMII_RXID:
> +	case PHY_INTERFACE_MODE_RGMII_TXID:
> +		val |= IFMODE_RGMII;
> +		/* Enable auto-negotiation for the MAC if its
> +		 * RGMII interface supports In-Band status.
> +		 */
> +		if (phylink_autoneg_inband(mode))
> +			val |= PM_IF_MODE_ENA;

I would prefer newer drivers not to use phylink_autoneg_inband()
anymore. Note that there is no need to support RGMII inband in the
kernel (nor is there any proper support without a "phylink_pcs"
being present to provide the inband status.)

> +static void netc_port_set_hd_flow_control(struct netc_port *np, bool en)
> +{
> +	if (!np->caps.half_duplex)
> +		return;
> +
> +	/* The HD_FCEN is used in conjunction with the PM_HD_FLOW_CTRL
> +	 * register, which has a default value, so currently we do not
> +	 * set it in the driver. The half duplex flow control works by
> +	 * the backpressure, and the backpressure is essentially just
> +	 * a long preamble transmitted on the link intended to create
> +	 * a collision and get the half duplex link partner to defer.
> +	 */
> +	netc_mac_port_rmw(np, NETC_PM_CMD_CFG(0), PM_CMD_CFG_HD_FCEN,
> +			  en ? PM_CMD_CFG_HD_FCEN : 0);

We don't support half duplex backpressure in the kernel. I notice
you always enable this whenever HD mode is negotiated, which means
there's no way for the user to disable it. Flow control can cause
problems. Ethernet relies on packet dropping for congestion
management.

> +static void imx94_switch_phylink_get_caps(int port,
> +					  struct phylink_config *config)
> +{
> +	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
> +				   MAC_1000FD;
> +
> +	switch (port) {
> +	case 0 ... 1:
> +		__set_bit(PHY_INTERFACE_MODE_SGMII,
> +			  config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_1000BASEX,
> +			  config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> +			  config->supported_interfaces);
> +		config->mac_capabilities |= MAC_2500FD;
> +		fallthrough;
> +	case 2:
> +		config->mac_capabilities |= MAC_10 | MAC_100;
> +		__set_bit(PHY_INTERFACE_MODE_MII,
> +			  config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_RMII,
> +			  config->supported_interfaces);
> +		if (port == 2)
> +			__set_bit(PHY_INTERFACE_MODE_REVMII,
> +				  config->supported_interfaces);

The "case 2" above already ensures that port is 2 here.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

On 3/23/26 10:30 AM, Russell King (Oracle) wrote:
> On Mon, Mar 23, 2026 at 02:07:49PM +0800, Wei Fang wrote:
>> +static void netc_port_set_mac_mode(struct netc_port *np,
>> +				   unsigned int mode,
>> +				   phy_interface_t phy_mode)
>> +{
>> +	u32 mask = PM_IF_MODE_IFMODE | PM_IF_MODE_REVMII | PM_IF_MODE_ENA;
>> +	u32 val = 0;
>> +
>> +	switch (phy_mode) {
>> +	case PHY_INTERFACE_MODE_RGMII:
>> +	case PHY_INTERFACE_MODE_RGMII_ID:
>> +	case PHY_INTERFACE_MODE_RGMII_RXID:
>> +	case PHY_INTERFACE_MODE_RGMII_TXID:
>> +		val |= IFMODE_RGMII;
>> +		/* Enable auto-negotiation for the MAC if its
>> +		 * RGMII interface supports In-Band status.
>> +		 */
>> +		if (phylink_autoneg_inband(mode))
>> +			val |= PM_IF_MODE_ENA;
> 
> I would prefer newer drivers not to use phylink_autoneg_inband()
> anymore. Note that there is no need to support RGMII inband in the
> kernel (nor is there any proper support without a "phylink_pcs"
> being present to provide the inband status.)
Would you mind sharing a patch adding a comment nearby
phylink_autoneg_inband(), explaining the above for future memory?

Thanks,

Paolo