Re: [PATCH 1/2] net: phy: microchip: add downshift tunable support for LAN88xx

[Andrew Lunn]

> +static int lan88xx_set_downshift(struct phy_device *phydev, u8 cnt)
> +{
> +	u32 mask = LAN78XX_PHY_CTRL3_DOWNSHIFT_CTRL_MASK |
> +		   LAN78XX_PHY_CTRL3_AUTO_DOWNSHIFT;
> +	u32 val;
> +
> +	if (cnt == DOWNSHIFT_DEV_DISABLE)
> +		return phy_modify_paged(phydev, 1, LAN78XX_PHY_CTRL3,
> +					LAN78XX_PHY_CTRL3_AUTO_DOWNSHIFT, 0);
> +
> +	if (cnt == DOWNSHIFT_DEV_DEFAULT_COUNT)
> +		cnt = 2;
> +
> +	switch (cnt) {
> +	case 2:
> +		val = LAN78XX_PHY_CTRL3_DOWNSHIFT_CTRL_2;
> +		break;
> +	case 3:
> +		val = LAN78XX_PHY_CTRL3_DOWNSHIFT_CTRL_3;
> +		break;
> +	case 4:
> +		val = LAN78XX_PHY_CTRL3_DOWNSHIFT_CTRL_4;
> +		break;
> +	case 5:
> +		val = LAN78XX_PHY_CTRL3_DOWNSHIFT_CTRL_5;
> +		break;
> +	default:
> +		return -EINVAL;

And this could be a range check followed by a FIELD_PREP(cnt - 2);

	Andrew