Re: [PATCH net-next 1/8] net: phy: realtek: rtl8221: allow to configure SERDES mode

[Steen Hegelund]

Hi Alexander,

On Thu, 2023-05-11 at 00:53 +0200, Alexander Couzens wrote:
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> 
> The rtl8221 supports multiple SERDES modes:
> - SGMII
> - 2500base-x
> - HiSGMII
> 
> Further it supports rate adaption on SERDES links to allow
> slow ethernet speeds (10/100/1000mbit) to work on 2500base-x/HiSGMII
> links without reducing the SERDES speed.
> 
> When operating without rate adapters the SERDES link will follow the
> ethernet speed.
> 
> Signed-off-by: Alexander Couzens <lynxis@xxxxxxx>
> ---
>  drivers/net/phy/realtek.c | 55 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
> index 3d99fd6664d7..a7dd5a075135 100644
> --- a/drivers/net/phy/realtek.c
> +++ b/drivers/net/phy/realtek.c
> @@ -53,6 +53,15 @@
>                                                  RTL8201F_ISR_LINK)
>  #define RTL8201F_IER                           0x13
> 
> +#define RTL8221B_MMD_SERDES_CTRL               MDIO_MMD_VEND1
> +#define RTL8221B_MMD_PHY_CTRL                  MDIO_MMD_VEND2
> +#define RTL8221B_SERDES_OPTION                 0x697a
> +#define RTL8221B_SERDES_OPTION_MODE_MASK       GENMASK(5, 0)
> +#define RTL8221B_SERDES_OPTION_MODE_2500BASEX_SGMII    0
> +#define RTL8221B_SERDES_OPTION_MODE_HISGMII_SGMII      1
> +#define RTL8221B_SERDES_OPTION_MODE_2500BASEX          2
> +#define RTL8221B_SERDES_OPTION_MODE_HISGMII            3
> +
>  #define RTL8366RB_POWER_SAVE                   0x15
>  #define RTL8366RB_POWER_SAVE_ON                        BIT(12)
> 
> @@ -849,6 +858,48 @@ static irqreturn_t rtl9000a_handle_interrupt(struct
> phy_device *phydev)
>         return IRQ_HANDLED;
>  }
> 
> +static int rtl8221b_config_init(struct phy_device *phydev)
> +{
> +       u16 option_mode;
> +
> +       switch (phydev->interface) {
> +       case PHY_INTERFACE_MODE_2500BASEX:
> +               if (!phydev->is_c45) {
> +                       option_mode = RTL8221B_SERDES_OPTION_MODE_2500BASEX;
> +                       break;
> +               }
> +               fallthrough;
> +       case PHY_INTERFACE_MODE_SGMII:
> +               option_mode = RTL8221B_SERDES_OPTION_MODE_2500BASEX_SGMII;
> +               break;
> +       default:
> +               return 0;
> +       }
> +
> +       phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL,
> +                     0x75f3, 0);

Please provide a symbol for the magic value.

> +
> +       phy_modify_mmd_changed(phydev, RTL8221B_MMD_SERDES_CTRL,
> +                              RTL8221B_SERDES_OPTION,
> +                              RTL8221B_SERDES_OPTION_MODE_MASK, option_mode);
> +       switch (option_mode) {
> +       case RTL8221B_SERDES_OPTION_MODE_2500BASEX_SGMII:
> +       case RTL8221B_SERDES_OPTION_MODE_2500BASEX:

This next section also uses a number of magic values.  Please convert to
symbols.

> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6a04,
> 0x0503);
> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6f10,
> 0xd455);
> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6f11,
> 0x8020);
> +               break;
> +       case RTL8221B_SERDES_OPTION_MODE_HISGMII_SGMII:
> +       case RTL8221B_SERDES_OPTION_MODE_HISGMII:
> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6a04,
> 0x0503);
> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6f10,
> 0xd433);
> +               phy_write_mmd(phydev, RTL8221B_MMD_SERDES_CTRL, 0x6f11,
> 0x8020);
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
>  static struct phy_driver realtek_drvs[] = {
>         {
>                 PHY_ID_MATCH_EXACT(0x00008201),
> @@ -970,6 +1021,7 @@ static struct phy_driver realtek_drvs[] = {
>                 .name           = "RTL8226B_RTL8221B 2.5Gbps PHY",
>                 .get_features   = rtl822x_get_features,
>                 .config_aneg    = rtl822x_config_aneg,
> +               .config_init    = rtl8221b_config_init,
>                 .read_status    = rtl822x_read_status,
>                 .suspend        = genphy_suspend,
>                 .resume         = rtlgen_resume,
> @@ -992,6 +1044,7 @@ static struct phy_driver realtek_drvs[] = {
>                 .name           = "RTL8226B-CG_RTL8221B-CG 2.5Gbps PHY",
>                 .get_features   = rtl822x_get_features,
>                 .config_aneg    = rtl822x_config_aneg,
> +               .config_init    = rtl8221b_config_init,
>                 .read_status    = rtl822x_read_status,
>                 .suspend        = genphy_suspend,
>                 .resume         = rtlgen_resume,
> @@ -1002,6 +1055,7 @@ static struct phy_driver realtek_drvs[] = {
>                 .name           = "RTL8221B-VB-CG 2.5Gbps PHY",
>                 .get_features   = rtl822x_get_features,
>                 .config_aneg    = rtl822x_config_aneg,
> +               .config_init    = rtl8221b_config_init,
>                 .read_status    = rtl822x_read_status,
>                 .suspend        = genphy_suspend,
>                 .resume         = rtlgen_resume,
> @@ -1012,6 +1066,7 @@ static struct phy_driver realtek_drvs[] = {
>                 .name           = "RTL8221B-VM-CG 2.5Gbps PHY",
>                 .get_features   = rtl822x_get_features,
>                 .config_aneg    = rtl822x_config_aneg,
> +               .config_init    = rtl8221b_config_init,
>                 .read_status    = rtl822x_read_status,
>                 .suspend        = genphy_suspend,
>                 .resume         = rtlgen_resume,
> --
> 2.40.0
> 
> 

Otherwise

Reviewed-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx>

Best Regards
Steen