Subject: Re: [net-next PATCH v5 7/9] net: phy: qcom: add support for QCA807x PHY Family

From: Christian Marangi <[email-masked]>
Date: Fri, 2 Feb 2024 18:44:22 +0100

On Fri, Feb 02, 2024 at 02:35:11AM +0100, Andrew Lunn wrote:
> > +static int qca807x_read_fiber_status(struct phy_device *phydev)
> > +{
> > +	int ss, err, lpa, old_link = phydev->link;
> > +
> > +	/* Update the link, but return if there was an error */
> > +	err = genphy_update_link(phydev);
> > +	if (err)
> > +		return err;
> > +
> > +	/* why bother the PHY if nothing can have changed */
> > +	if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
> > +		return 0;
> > +
> > +	phydev->speed = SPEED_UNKNOWN;
> > +	phydev->duplex = DUPLEX_UNKNOWN;
> > +	phydev->pause = 0;
> > +	phydev->asym_pause = 0;
> > +
> > +	if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
> > +		lpa = phy_read(phydev, MII_LPA);
> > +		if (lpa < 0)
> > +			return lpa;
> > +
> > +		linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
> > +				 phydev->lp_advertising, lpa & LPA_LPACK);
> > +		linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
> > +				 phydev->lp_advertising, lpa & LPA_1000XFULL);
> > +		linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT,
> > +				 phydev->lp_advertising, lpa & LPA_1000XPAUSE);
> > +		linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
> > +				 phydev->lp_advertising,
> > +				 lpa & LPA_1000XPAUSE_ASYM);
> > +
> > +		phy_resolve_aneg_linkmode(phydev);
> > +	}
> 
> This looks a lot like genphy_c37_read_status(). Can it be used?
>

Yes but I had to expand genphy_c37_read_status. Hope it will be OK.

> > +
> > +	/* Read the QCA807x PHY-Specific Status register fiber page,
> > +	 * which indicates the speed and duplex that the PHY is actually
> > +	 * using, irrespective of whether we are in autoneg mode or not.
> > +	 */
> > +	ss = phy_read(phydev, AT803X_SPECIFIC_STATUS);
> > +	if (ss < 0)
> > +		return ss;
> > +
> > +	if (ss & AT803X_SS_SPEED_DUPLEX_RESOLVED) {
> > +		switch (FIELD_GET(AT803X_SS_SPEED_MASK, ss)) {
> > +		case AT803X_SS_SPEED_100:
> > +			phydev->speed = SPEED_100;
> > +			break;
> > +		case AT803X_SS_SPEED_1000:
> > +			phydev->speed = SPEED_1000;
> > +			break;
> > +		}
> > +
> > +		if (ss & AT803X_SS_DUPLEX)
> > +			phydev->duplex = DUPLEX_FULL;
> > +		else
> > +			phydev->duplex = DUPLEX_HALF;
> > +	}
> > +
> > +	return 0;
> > +}
> 
> 
> > +static int qca807x_phy_package_probe_once(struct phy_device *phydev)
> > +{
> > +	struct phy_package_shared *shared = phydev->shared;
> > +	struct qca807x_shared_priv *priv = shared->priv;
> > +	unsigned int tx_driver_strength = 0;
> > +	const char *package_mode_name;
> > +
> > +	of_property_read_u32(shared->np, "qcom,tx-driver-strength",
> > +			     &tx_driver_strength);
> > +	switch (tx_driver_strength) {
> > +	case 140:
> > +		priv->tx_driver_strength = PQSGMII_TX_DRIVER_140MV;
> > +		break;
> > +	case 160:
> > +		priv->tx_driver_strength = PQSGMII_TX_DRIVER_160MV;
> > +		break;
> > +	case 180:
> > +		priv->tx_driver_strength = PQSGMII_TX_DRIVER_180MV;
> > +		break;
> > +	case 200:
> 
> ...
> 
> > +	case 500:
> > +		priv->tx_driver_strength = PQSGMII_TX_DRIVER_500MV;
> > +		break;
> > +	case 600:
> > +	default:
> 
> If its missing default to 600. But if its an invalid value, return
> -EINVAL.
> 
> > +		priv->tx_driver_strength = PQSGMII_TX_DRIVER_600MV;
> > +	}
> > +
> > +	priv->package_mode = PHY_INTERFACE_MODE_NA;
> > +	if (!of_property_read_string(shared->np, "qcom,package-mode",
> > +				     &package_mode_name)) {
> > +		if (!strcasecmp(package_mode_name,
> > +				phy_modes(PHY_INTERFACE_MODE_PSGMII)))
> > +			priv->package_mode = PHY_INTERFACE_MODE_PSGMII;
> > +
> > +		if (!strcasecmp(package_mode_name,
> > +				phy_modes(PHY_INTERFACE_MODE_QSGMII)))
> > +			priv->package_mode = PHY_INTERFACE_MODE_QSGMII;
> 
> Again, return -EINVAL if it is neither.
> 
> > +static int qca807x_phy_package_config_init_once(struct phy_device *phydev)
> > +{
> > +	struct phy_package_shared *shared = phydev->shared;
> > +	struct qca807x_shared_priv *priv = shared->priv;
> > +	int val, ret;
> > +
> > +	phy_lock_mdio_bus(phydev);
> > +
> > +	/* Set correct PHY package mode */
> > +	val = __phy_package_read(phydev, QCA807X_COMBO_ADDR,
> > +				 QCA807X_CHIP_CONFIGURATION);
> > +	val &= ~QCA807X_CHIP_CONFIGURATION_MODE_CFG_MASK;
> > +	if (priv->package_mode == PHY_INTERFACE_MODE_QSGMII)
> > +		val |= QCA807X_CHIP_CONFIGURATION_MODE_QSGMII_SGMII;
> > +	else
> > +		val |= QCA807X_CHIP_CONFIGURATION_MODE_PSGMII_ALL_COPPER;
> 
> What about priv->package_mode == PHY_INTERFACE_MODE_NA;
>

I changed this to a switch and added some comments to make this more
clear. We default to PSGMII if package-mode is not defined. (will also
update schema with default value)

-- 
	Ansuel