Subject: Re: [net-next RFC PATCH v5 10/10] net: airoha: add phylink support for GDM2/3/4

From: Lorenzo Bianconi <[email-masked]>
Date: Tue, 5 May 2026 23:56:32 +0200

> Add phylink support for GDM2/3/4 port that require configuration of the
> PCS to make the external PHY or attached SFP cage work.
> 
> These needs to be defined in the GDM port node using the pcs-handle
> property.
> 
> Signed-off-by: Christian Marangi <[email-masked]>

Hi Christian,

just a couple of nits inline.

Regards,
Lorenzo

> ---
>  drivers/net/ethernet/airoha/Kconfig       |   1 +
>  drivers/net/ethernet/airoha/airoha_eth.c  | 144 +++++++++++++++++++++-
>  drivers/net/ethernet/airoha/airoha_eth.h  |   3 +
>  drivers/net/ethernet/airoha/airoha_regs.h |  12 ++
>  4 files changed, 159 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/airoha/Kconfig b/drivers/net/ethernet/airoha/Kconfig
> index ad3ce501e7a5..38dcc76e5998 100644
> --- a/drivers/net/ethernet/airoha/Kconfig
> +++ b/drivers/net/ethernet/airoha/Kconfig
> @@ -20,6 +20,7 @@ config NET_AIROHA
>  	depends on NET_DSA || !NET_DSA
>  	select NET_AIROHA_NPU
>  	select PAGE_POOL
> +	select PHYLINK
>  	help
>  	  This driver supports the gigabit ethernet MACs in the
>  	  Airoha SoC family.
> diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> index 2bd79da70934..ad0328a25422 100644
> --- a/drivers/net/ethernet/airoha/airoha_eth.c
> +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> @@ -8,6 +8,7 @@
>  #include <linux/of_reserved_mem.h>
>  #include <linux/platform_device.h>
>  #include <linux/tcp.h>
> +#include <linux/pcs/pcs.h>
>  #include <linux/u64_stats_sync.h>
>  #include <net/dst_metadata.h>
>  #include <net/page_pool/helpers.h>
> @@ -71,6 +72,11 @@ static void airoha_qdma_irq_disable(struct airoha_irq_bank *irq_bank,
>  	airoha_qdma_set_irqmask(irq_bank, index, mask, 0);
>  }
>  
> +static bool airhoa_is_phy_external(struct airoha_gdm_port *port)
> +{
> +	return port->id != 1;

I guess you can use AIROHA_GDM1_IDX here.

> +}
> +
>  static void airoha_set_macaddr(struct airoha_gdm_port *port, const u8 *addr)
>  {
>  	struct airoha_eth *eth = port->qdma->eth;
> @@ -1644,6 +1650,17 @@ static int airoha_dev_open(struct net_device *dev)
>  	struct airoha_qdma *qdma = port->qdma;
>  	u32 pse_port = FE_PSE_PORT_PPE1;
>  
> +	if (airhoa_is_phy_external(port)) {
> +		err = phylink_of_phy_connect(port->phylink, dev->dev.of_node, 0);
> +		if (err) {
> +			netdev_err(dev, "%s: could not attach PHY: %d\n", __func__,
> +				   err);
> +			return err;
> +		}
> +
> +		phylink_start(port->phylink);
> +	}
> +
>  	netif_tx_start_all_queues(dev);
>  	err = airoha_set_vip_for_gdm_port(port, true);
>  	if (err)
> @@ -1707,6 +1724,11 @@ static int airoha_dev_stop(struct net_device *dev)
>  		}
>  	}
>  
> +	if (airhoa_is_phy_external(port)) {
> +		phylink_stop(port->phylink);
> +		phylink_disconnect_phy(port->phylink);
> +	}
> +
>  	return 0;
>  }
>  
> @@ -2883,6 +2905,115 @@ bool airoha_is_valid_gdm_port(struct airoha_eth *eth,
>  	return false;
>  }
>  
> +static void airoha_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 airoha_gdm_port *port = container_of(config, struct airoha_gdm_port,
> +						    phylink_config);
> +	struct airoha_qdma *qdma = port->qdma;
> +	struct airoha_eth *eth = qdma->eth;

since you do not need qdma pointer here, you can just do port->eth here.

> +	u32 frag_size_tx, frag_size_rx;
> +
> +	if (port->id != 4)

same here, AIROHA_GDM4_IDX

> +		return;
> +
> +	switch (speed) {
> +	case SPEED_10000:
> +	case SPEED_5000:
> +		frag_size_tx = 8;
> +		frag_size_rx = 8;
> +		break;
> +	case SPEED_2500:
> +		frag_size_tx = 2;
> +		frag_size_rx = 1;
> +		break;
> +	default:
> +		frag_size_tx = 1;
> +		frag_size_rx = 0;
> +	}
> +
> +	/* Configure TX/RX frag based on speed */
> +	airoha_fe_rmw(eth, REG_GDMA4_TMBI_FRAG,
> +		      GDMA4_SGMII0_TX_FRAG_SIZE_MASK,
> +		      FIELD_PREP(GDMA4_SGMII0_TX_FRAG_SIZE_MASK,
> +				 frag_size_tx));
> +
> +	airoha_fe_rmw(eth, REG_GDMA4_RMBI_FRAG,
> +		      GDMA4_SGMII0_RX_FRAG_SIZE_MASK,
> +		      FIELD_PREP(GDMA4_SGMII0_RX_FRAG_SIZE_MASK,
> +				 frag_size_rx));
> +}
> +
> +static const struct phylink_mac_ops airoha_phylink_ops = {
> +	.mac_link_up = airoha_mac_link_up,
> +};
> +
> +static int airoha_setup_phylink(struct net_device *dev)
> +{
> +	struct airoha_gdm_port *port = netdev_priv(dev);
> +	struct device_node *np = dev->dev.of_node;
> +	struct phylink_pcs **available_pcs;
> +	phy_interface_t phy_mode;
> +	struct phylink *phylink;
> +	unsigned int num_pcs;
> +	int err;
> +
> +	err = of_get_phy_mode(np, &phy_mode);
> +	if (err) {
> +		dev_err(&dev->dev, "incorrect phy-mode\n");
> +		return err;
> +	}
> +
> +	port->phylink_config.dev = &dev->dev;
> +	port->phylink_config.type = PHYLINK_NETDEV;
> +	port->phylink_config.mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
> +						MAC_10 | MAC_100 | MAC_1000 | MAC_2500FD |
> +						MAC_5000FD | MAC_10000FD;
> +
> +	err = fwnode_phylink_pcs_parse(dev_fwnode(&dev->dev), NULL, &num_pcs);
> +	if (err)
> +		return err;
> +
> +	available_pcs = kcalloc(num_pcs, sizeof(*available_pcs), GFP_KERNEL);
> +	if (!available_pcs)
> +		return -ENOMEM;
> +
> +	err = fwnode_phylink_pcs_parse(dev_fwnode(&dev->dev), available_pcs,
> +				       &num_pcs);
> +	if (err)
> +		goto out;
> +
> +	port->phylink_config.available_pcs = available_pcs;
> +	port->phylink_config.num_available_pcs = num_pcs;
> +
> +	__set_bit(PHY_INTERFACE_MODE_SGMII,
> +		  port->phylink_config.supported_interfaces);
> +	__set_bit(PHY_INTERFACE_MODE_1000BASEX,
> +		  port->phylink_config.supported_interfaces);
> +	__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> +		  port->phylink_config.supported_interfaces);
> +	__set_bit(PHY_INTERFACE_MODE_USXGMII,
> +		  port->phylink_config.supported_interfaces);
> +
> +	phy_interface_copy(port->phylink_config.pcs_interfaces,
> +			   port->phylink_config.supported_interfaces);
> +
> +	phylink = phylink_create(&port->phylink_config,
> +				 of_fwnode_handle(np),
> +				 phy_mode, &airoha_phylink_ops);
> +	if (IS_ERR(phylink)) {
> +		err = PTR_ERR(phylink);
> +		goto out;
> +	}
> +
> +	port->phylink = phylink;
> +out:
> +	kfree(available_pcs);
> +
> +	return err;
> +}
> +
>  static int airoha_alloc_gdm_port(struct airoha_eth *eth,
>  				 struct device_node *np)
>  {
> @@ -2954,6 +3085,12 @@ static int airoha_alloc_gdm_port(struct airoha_eth *eth,
>  	port->id = id;
>  	eth->ports[p] = port;
>  
> +	if (airhoa_is_phy_external(port)) {
> +		err = airoha_setup_phylink(dev);

should it be in airoha_register_gdm_devices()?

> +		if (err)
> +			return err;
> +	}
> +
>  	return airoha_metadata_dst_alloc(port);
>  }
>  
> @@ -3081,8 +3218,11 @@ static int airoha_probe(struct platform_device *pdev)
>  		if (!port)
>  			continue;
>  
> -		if (port->dev->reg_state == NETREG_REGISTERED)
> +		if (port->dev->reg_state == NETREG_REGISTERED) {
> +			if (airhoa_is_phy_external(port))
> +				phylink_destroy(port->phylink);
>  			unregister_netdev(port->dev);
> +		}
>  		airoha_metadata_dst_free(port);
>  	}
>  	airoha_hw_cleanup(eth);
> @@ -3107,6 +3247,8 @@ static void airoha_remove(struct platform_device *pdev)
>  		if (!port)
>  			continue;
>  
> +		if (airhoa_is_phy_external(port))
> +			phylink_destroy(port->phylink);
>  		unregister_netdev(port->dev);
>  		airoha_metadata_dst_free(port);
>  	}
> diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ethernet/airoha/airoha_eth.h
> index af29fc74165b..e5c70f1fa4f1 100644
> --- a/drivers/net/ethernet/airoha/airoha_eth.h
> +++ b/drivers/net/ethernet/airoha/airoha_eth.h
> @@ -538,6 +538,9 @@ struct airoha_gdm_port {
>  	struct net_device *dev;
>  	int id;
>  
> +	struct phylink *phylink;
> +	struct phylink_config phylink_config;
> +
>  	struct airoha_hw_stats stats;
>  
>  	DECLARE_BITMAP(qos_sq_bmap, AIROHA_NUM_QOS_CHANNELS);
> diff --git a/drivers/net/ethernet/airoha/airoha_regs.h b/drivers/net/ethernet/airoha/airoha_regs.h
> index 436f3c8779c1..27f2583e143a 100644
> --- a/drivers/net/ethernet/airoha/airoha_regs.h
> +++ b/drivers/net/ethernet/airoha/airoha_regs.h
> @@ -358,6 +358,18 @@
>  #define IP_FRAGMENT_PORT_MASK		GENMASK(8, 5)
>  #define IP_FRAGMENT_NBQ_MASK		GENMASK(4, 0)
>  
> +#define REG_GDMA4_TMBI_FRAG		0x2028
> +#define GDMA4_SGMII1_TX_WEIGHT_MASK	GENMASK(31, 26)
> +#define GDMA4_SGMII1_TX_FRAG_SIZE_MASK	GENMASK(25, 16)
> +#define GDMA4_SGMII0_TX_WEIGHT_MASK	GENMASK(15, 10)
> +#define GDMA4_SGMII0_TX_FRAG_SIZE_MASK	GENMASK(9, 0)
> +
> +#define REG_GDMA4_RMBI_FRAG		0x202c
> +#define GDMA4_SGMII1_RX_WEIGHT_MASK	GENMASK(31, 26)
> +#define GDMA4_SGMII1_RX_FRAG_SIZE_MASK	GENMASK(25, 16)
> +#define GDMA4_SGMII0_RX_WEIGHT_MASK	GENMASK(15, 10)
> +#define GDMA4_SGMII0_RX_FRAG_SIZE_MASK	GENMASK(9, 0)
> +
>  #define REG_MC_VLAN_EN			0x2100
>  #define MC_VLAN_EN_MASK			BIT(0)
>  
> -- 
> 2.53.0
>