Re: [PATCH net-next v5] net: stmmac: dwmac-qcom-ethqos: Add support for 2.5G SGMII

["Abhishek Chauhan (ABC)" <quic_abchauha@quicinc.com>]

On 2/19/2024 9:07 PM, Sneh Shah wrote:
> Serdes phy needs to operate at 2500 mode for 2.5G speed and 1000
> mode for 1G/100M/10M speed.
> Added changes to configure serdes phy and mac based on link speed.
> Changing serdes phy speed involves multiple register writes for
> serdes block. To avoid redundant write operations only update serdes
> phy when new speed is different.
> For 2500 speed MAC PCS autoneg needs to disabled. Added changes to
> disable MAC PCS autoneg if ANE parameter is not set.
> 
> Signed-off-by: Sneh Shah <quic_snehshah@quicinc.com>
Tested-by: Abhishek Chauhan <quic_abchauha@quicinc.com> # sa8775p-ride
Reviewed-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
> ---
> v5 changelog:
> - Updated commit message with more details on MAC PCS autoneg disable
> v4 changelog:
> - Made cosmetic changes
> v3 changelog:
> - updated commit message
> ---
> v2 changelog:
> - updated stmmac_pcs_ane to support autoneg disable
> - Update serdes speed to 1000 for 100M and 10M also---
> ---
>  .../stmicro/stmmac/dwmac-qcom-ethqos.c        | 26 +++++++++++++++++++
>  .../net/ethernet/stmicro/stmmac/stmmac_pcs.h  |  2 ++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> index 31631e3f89d0..6bbdbb7bef44 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> @@ -106,6 +106,7 @@ struct qcom_ethqos {
>  	struct clk *link_clk;
>  	struct phy *serdes_phy;
>  	unsigned int speed;
> +	int serdes_speed;
>  	phy_interface_t phy_mode;
>  
>  	const struct ethqos_emac_por *por;
> @@ -606,19 +607,39 @@ static int ethqos_configure_rgmii(struct qcom_ethqos *ethqos)
>   */
>  static int ethqos_configure_sgmii(struct qcom_ethqos *ethqos)
>  {
> +	struct net_device *dev = platform_get_drvdata(ethqos->pdev);
> +	struct stmmac_priv *priv = netdev_priv(dev);
>  	int val;
>  
>  	val = readl(ethqos->mac_base + MAC_CTRL_REG);
>  
>  	switch (ethqos->speed) {
> +	case SPEED_2500:
> +		val &= ~ETHQOS_MAC_CTRL_PORT_SEL;
> +		rgmii_updatel(ethqos, RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
> +			      RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
> +			      RGMII_IO_MACRO_CONFIG2);
> +		if (ethqos->serdes_speed != SPEED_2500)
> +			phy_set_speed(ethqos->serdes_phy, SPEED_2500);
> +		ethqos->serdes_speed = SPEED_2500;
> +		stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 0, 0, 0);
> +		break;
>  	case SPEED_1000:
>  		val &= ~ETHQOS_MAC_CTRL_PORT_SEL;
>  		rgmii_updatel(ethqos, RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
>  			      RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
>  			      RGMII_IO_MACRO_CONFIG2);
> +		if (ethqos->serdes_speed != SPEED_1000)
> +			phy_set_speed(ethqos->serdes_phy, SPEED_1000);
> +		ethqos->serdes_speed = SPEED_1000;
> +		stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
>  		break;
>  	case SPEED_100:
>  		val |= ETHQOS_MAC_CTRL_PORT_SEL | ETHQOS_MAC_CTRL_SPEED_MODE;
> +		if (ethqos->serdes_speed != SPEED_1000)
> +			phy_set_speed(ethqos->serdes_phy, SPEED_1000);
> +		ethqos->serdes_speed = SPEED_1000;
> +		stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
>  		break;
>  	case SPEED_10:
>  		val |= ETHQOS_MAC_CTRL_PORT_SEL;
> @@ -627,6 +648,10 @@ static int ethqos_configure_sgmii(struct qcom_ethqos *ethqos)
>  			      FIELD_PREP(RGMII_CONFIG_SGMII_CLK_DVDR,
>  					 SGMII_10M_RX_CLK_DVDR),
>  			      RGMII_IO_MACRO_CONFIG);
> +		if (ethqos->serdes_speed != SPEED_1000)
> +			phy_set_speed(ethqos->serdes_phy, ethqos->speed);
> +		ethqos->serdes_speed = SPEED_1000;
> +		stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
>  		break;
>  	}
>  
> @@ -799,6 +824,7 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
>  				     "Failed to get serdes phy\n");
>  
>  	ethqos->speed = SPEED_1000;
> +	ethqos->serdes_speed = SPEED_1000;
>  	ethqos_update_link_clk(ethqos, SPEED_1000);
>  	ethqos_set_func_clk_en(ethqos);
>  
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> index aefc121464b5..13a30e6df4c1 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> @@ -110,6 +110,8 @@ static inline void dwmac_ctrl_ane(void __iomem *ioaddr, u32 reg, bool ane,
>  	/* Enable and restart the Auto-Negotiation */
>  	if (ane)
>  		value |= GMAC_AN_CTRL_ANE | GMAC_AN_CTRL_RAN;
> +	else
> +		value &= ~GMAC_AN_CTRL_ANE;
>  
>  	/* In case of MAC-2-MAC connection, block is configured to operate
>  	 * according to MAC conf register.