[net-next PATCH v8 3/4] net: dsa: Add Airoha AN8855 5-Port Gigabit DSA Switch driver

[Maxime Chevallier]

Hello Christian,

On Wed,  4 Dec 2024 08:24:10 +0100
Christian Marangi <ansuelsmth at gmail.com> wrote:

> Add Airoha AN8855 5-Port Gigabit DSA switch.
> 
> The switch is also a nvmem-provider as it does have EFUSE to calibrate
> the internal PHYs.
> 
> Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>

[...]

My two-cents review below :)

> +static void
> +an8855_phylink_mac_config(struct phylink_config *config, unsigned int mode,
> +			  const struct phylink_link_state *state)
> +{
> +	struct dsa_port *dp = dsa_phylink_to_port(config);
> +	struct dsa_switch *ds = dp->ds;
> +	struct an8855_priv *priv;
> +	int port = dp->index;
> +
> +	priv = ds->priv;
> +
> +	if (port != 5) {
> +		if (port > 5)
> +			dev_err(ds->dev, "unsupported port: %d", port);
> +		return;
> +	}

Looks like the above condition can be simplified to :

	if (port > 5)
		dev_err(...);


> +
> +	regmap_update_bits(priv->regmap, AN8855_PMCR_P(port),
> +			   AN8855_PMCR_IFG_XMIT | AN8855_PMCR_MAC_MODE |
> +			   AN8855_PMCR_BACKOFF_EN | AN8855_PMCR_BACKPR_EN,
> +			   FIELD_PREP(AN8855_PMCR_IFG_XMIT, 0x1) |
> +			   AN8855_PMCR_MAC_MODE | AN8855_PMCR_BACKOFF_EN |
> +			   AN8855_PMCR_BACKPR_EN);
> +}
> +
> +static void an8855_phylink_get_caps(struct dsa_switch *ds, int port,
> +				    struct phylink_config *config)
> +{
> +	switch (port) {
> +	case 0:
> +	case 1:
> +	case 2:
> +	case 3:
> +	case 4:
> +		__set_bit(PHY_INTERFACE_MODE_GMII,
> +			  config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_INTERNAL,
> +			  config->supported_interfaces);
> +		break;
> +	case 5:
> +		phy_interface_set_rgmii(config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_SGMII,
> +			  config->supported_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> +			  config->supported_interfaces);
> +		break;
> +	}
> +
> +	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
> +				   MAC_10 | MAC_100 | MAC_1000FD;

For port 5, you may also add the MAC_2500FD capability as it supports
2500BASEX ?

> +}
> +

[...]

> +
> +static void
> +an8855_phylink_mac_link_up(struct phylink_config *config,
> +			   struct phy_device *phydev, 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 an8855_priv *priv = dp->ds->priv;
> +	int port = dp->index;
> +	u32 reg;
> +
> +	reg = regmap_read(priv->regmap, AN8855_PMCR_P(port), &reg);
> +	if (phylink_autoneg_inband(mode)) {
> +		reg &= ~AN8855_PMCR_FORCE_MODE;
> +	} else {
> +		reg |= AN8855_PMCR_FORCE_MODE | AN8855_PMCR_FORCE_LNK;
> +
> +		reg &= ~AN8855_PMCR_FORCE_SPEED;
> +		switch (speed) {
> +		case SPEED_10:
> +			reg |= AN8855_PMCR_FORCE_SPEED_10;
> +			break;
> +		case SPEED_100:
> +			reg |= AN8855_PMCR_FORCE_SPEED_100;
> +			break;
> +		case SPEED_1000:
> +			reg |= AN8855_PMCR_FORCE_SPEED_1000;
> +			break;
> +		case SPEED_2500:
> +			reg |= AN8855_PMCR_FORCE_SPEED_2500;
> +			break;
> +		case SPEED_5000:
> +			reg |= AN8855_PMCR_FORCE_SPEED_5000;
> +			break;

There's no mention of any mode that can give support for the 5000Mbps
speed, is it a leftover from previous work on the driver ?

> +		}
> +
> +		reg &= ~AN8855_PMCR_FORCE_FDX;
> +		if (duplex == DUPLEX_FULL)
> +			reg |= AN8855_PMCR_FORCE_FDX;
> +
> +		reg &= ~AN8855_PMCR_RX_FC_EN;
> +		if (rx_pause || dsa_port_is_cpu(dp))
> +			reg |= AN8855_PMCR_RX_FC_EN;
> +
> +		reg &= ~AN8855_PMCR_TX_FC_EN;
> +		if (rx_pause || dsa_port_is_cpu(dp))
> +			reg |= AN8855_PMCR_TX_FC_EN;
> +
> +		/* Disable any EEE options */
> +		reg &= ~(AN8855_PMCR_FORCE_EEE5G | AN8855_PMCR_FORCE_EEE2P5G |
> +			 AN8855_PMCR_FORCE_EEE1G | AN8855_PMCR_FORCE_EEE100);
> +	}
> +
> +	reg |= AN8855_PMCR_TX_EN | AN8855_PMCR_RX_EN;
> +
> +	regmap_write(priv->regmap, AN8855_PMCR_P(port), reg);
> +}
> +
> +static void an8855_pcs_get_state(struct phylink_pcs *pcs,
> +				 struct phylink_link_state *state)
> +{
> +	struct an8855_priv *priv = container_of(pcs, struct an8855_priv, pcs);
> +	u32 val;
> +	int ret;
> +
> +	ret = regmap_read(priv->regmap, AN8855_PMSR_P(AN8855_CPU_PORT), &val);
> +	if (ret < 0) {
> +		state->link = false;
> +		return;
> +	}
> +
> +	state->link = !!(val & AN8855_PMSR_LNK);
> +	state->an_complete = state->link;
> +	state->duplex = (val & AN8855_PMSR_DPX) ? DUPLEX_FULL :
> +						  DUPLEX_HALF;
> +
> +	switch (val & AN8855_PMSR_SPEED) {
> +	case AN8855_PMSR_SPEED_10:
> +		state->speed = SPEED_10;
> +		break;
> +	case AN8855_PMSR_SPEED_100:
> +		state->speed = SPEED_100;
> +		break;
> +	case AN8855_PMSR_SPEED_1000:
> +		state->speed = SPEED_1000;
> +		break;
> +	case AN8855_PMSR_SPEED_2500:
> +		state->speed = SPEED_2500;
> +		break;
> +	case AN8855_PMSR_SPEED_5000:
> +		state->speed = SPEED_5000;

Same here for the SPEED_5000, unless i'm missing something :)

Thanks,

Maxime