[U-Boot] [PATCH 1/2] sun8i_emac: add support for setting EMAC TX/RX delay

[Jagan Teki <jagan@amarulasolutions.com>]

On Fri, Nov 16, 2018 at 9:08 PM Alexander Weidinger
<alexander.weidinger@tum.de> wrote:
>
> From: Icenowy Zheng <icenowy@aosc.io>
>
> Some boards have the EMAC TX/RX lanes wired with a different length with
> the clock lane, which can be workarounded by setting a TX/RX delay in
> the EMAC.
>
> This kind of delays are already defined in the newest device tree
> binding of dwmac-sun8i, which has already entered linux-next.
>
> Add support for setting these delays.
>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> ---
>  drivers/net/sun8i_emac.c | 31 +++++++++++++++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
> index 3ba3a1ff8b..230ff045d5 100644
> --- a/drivers/net/sun8i_emac.c
> +++ b/drivers/net/sun8i_emac.c
> @@ -60,6 +60,10 @@
>  #define SC_ETCS_MASK           GENMASK(1, 0)
>  #define SC_ETCS_EXT_GMII       0x1
>  #define SC_ETCS_INT_GMII       0x2
> +#define SC_ETXDC_MASK          GENMASK(12, 10)
> +#define SC_ETXDC_OFFSET                10
> +#define SC_ERXDC_MASK          GENMASK(9, 5)
> +#define SC_ERXDC_OFFSET                5
>
>  #define CONFIG_MDIO_TIMEOUT    (3 * CONFIG_SYS_HZ)
>
> @@ -140,6 +144,8 @@ struct emac_eth_dev {
>  struct sun8i_eth_pdata {
>         struct eth_pdata eth_pdata;
>         u32 reset_delays[3];
> +       int tx_delay_ps;
> +       int rx_delay_ps;
>  };
>
>
> @@ -273,7 +279,8 @@ static int sun8i_emac_set_syscon_ephy(struct emac_eth_dev *priv, u32 *reg)
>         return 0;
>  }
>
> -static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
> +static int sun8i_emac_set_syscon(struct sun8i_eth_pdata *pdata,
> +                                struct emac_eth_dev *priv)
>  {
>         int ret;
>         u32 reg;
> @@ -312,6 +319,14 @@ static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
>                 return -EINVAL;
>         }
>
> +       if (pdata->tx_delay_ps)
> +               reg |= ((pdata->tx_delay_ps / 100) << SC_ETXDC_OFFSET)
> +                        & SC_ETXDC_MASK;
> +
> +       if (pdata->rx_delay_ps)
> +               reg |= ((pdata->rx_delay_ps / 100) << SC_ERXDC_OFFSET)
> +                        & SC_ERXDC_MASK;
> +
>         writel(reg, priv->sysctl_reg + 0x30);
>
>         return 0;
> @@ -790,7 +805,7 @@ static int sun8i_emac_eth_probe(struct udevice *dev)
>         priv->mac_reg = (void *)pdata->iobase;
>
>         sun8i_emac_board_setup(priv);
> -       sun8i_emac_set_syscon(priv);
> +       sun8i_emac_set_syscon((struct sun8i_eth_pdata *)pdata, priv);

We can get the platdata using dev_get_platdata instead of this type casting.