[U-Boot] [PATCH 6/9] net: sun8i_emac: Support RX/TX delay chains

[Joe Hershberger]

On Fri, Sep 22, 2017 at 2:26 AM, Chen-Yu Tsai <wens at csie.org> wrote:
> The EMAC syscon has configurable RX/TX delay chains for use with RGMII
> PHYs.
>
> This adds support for configuring them via device tree properties. The
> property names and format were defined in Linux's dwmac-sun8i binding
> that was merged at one point.
>
> Signed-off-by: Chen-Yu Tsai <wens at csie.org>
> ---
>  drivers/net/sun8i_emac.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
> index 09bbb2cdb5ca..5fa1b4c170d7 100644
> --- a/drivers/net/sun8i_emac.c
> +++ b/drivers/net/sun8i_emac.c
> @@ -56,6 +56,10 @@
>  #define H3_EPHY_SELECT         BIT(15) /* 1: internal PHY, 0: external PHY */
>
>  #define SC_RMII_EN             BIT(13)
> +#define SC_TXDC_SHIFT          10
> +#define SC_TXDC_MASK           GENMASK(2, 0)
> +#define SC_RXDC_SHIFT          5
> +#define SC_RXDC_MASK           GENMASK(4, 0)
>  #define SC_EPIT                        BIT(2) /* 1: RGMII, 0: MII */
>  #define SC_ETCS_MASK           GENMASK(1, 0)
>  #define SC_ETCS_EXT_GMII       0x1
> @@ -125,6 +129,8 @@ struct emac_eth_dev {
>         u32 addr;
>         u32 tx_slot;
>         bool use_internal_phy;
> +       u32 tx_delay;
> +       u32 rx_delay;
>
>         enum emac_variant variant;
>         void *mac_reg;
> @@ -290,6 +296,12 @@ static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
>         if (priv->variant == H3_EMAC || priv->variant == A64_EMAC)
>                 reg &= ~SC_RMII_EN;
>
> +       /* Configure RX/TX delay chains */
> +       reg &= ~(SC_RXDC_MASK << SC_RXDC_SHIFT);
> +       reg &= ~(SC_TXDC_MASK << SC_TXDC_SHIFT);
> +       reg |= (priv->rx_delay & SC_RXDC_MASK) << SC_RXDC_SHIFT;
> +       reg |= (priv->tx_delay & SC_TXDC_MASK) << SC_TXDC_SHIFT;

Why not use bitfield_replace_by_mask() from include/bitfield.h?

> +
>         switch (priv->interface) {
>         case PHY_INTERFACE_MODE_MII:
>                 /* default */
> @@ -836,6 +848,19 @@ static int sun8i_emac_eth_ofdata_to_platdata(struct udevice *dev)
>         }
>  #endif
>
> +       /* Get RX/TX delays for RGMII */
> +       priv->rx_delay = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
> +                                        "allwinner,rx-delay-ps", 0);
> +       if (priv->rx_delay % 100 || priv->rx_delay > 3100)
> +               debug("%s: invalid rx delay value\n", __func__);
> +       priv->rx_delay /= 100;
> +
> +       priv->tx_delay = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
> +                                        "allwinner,tx-delay-ps", 0);
> +       if (priv->tx_delay % 100 || priv->tx_delay > 800)
> +               debug("%s: invalid tx delay value\n", __func__);
> +       priv->tx_delay /= 100;
> +
>         return 0;
>  }
>
> --
> 2.14.1
>
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