[PATCH net-next v11 2/5] net: spacemit: Add K1 Ethernet MAC

[Andrew Lunn]

> +static u32 emac_rd(struct emac_priv *priv, u32 reg)
> +{
> +	return readl(priv->iobase + reg);
> +}

> +static int emac_mii_read(struct mii_bus *bus, int phy_addr, int regnum)
> +{
> +	struct emac_priv *priv = bus->priv;
> +	u32 cmd = 0, val;
> +	int ret;
> +
> +	cmd |= FIELD_PREP(MREGBIT_PHY_ADDRESS, phy_addr);
> +	cmd |= FIELD_PREP(MREGBIT_REGISTER_ADDRESS, regnum);
> +	cmd |= MREGBIT_START_MDIO_TRANS | MREGBIT_MDIO_READ_WRITE;
> +
> +	emac_wr(priv, MAC_MDIO_DATA, 0x0);
> +	emac_wr(priv, MAC_MDIO_CONTROL, cmd);
> +
> +	ret = readl_poll_timeout(priv->iobase + MAC_MDIO_CONTROL, val,
> +				 !(val & MREGBIT_START_MDIO_TRANS), 100, 10000);
> +
> +	if (ret)
> +		return ret;
> +
> +	val = emac_rd(priv, MAC_MDIO_DATA);
> +	return val;

emac_rd() returns a u32. Is it guaranteed by the hardware that the
upper word is 0? Maybe this needs to be masked?

	Andrew