Re: [PATCH v5 08/12] net: stmmac: starfive_dmac: Add phy interface settings

[Andrew Lunn <andrew@lunn.ch>]

> +static int starfive_dwmac_set_mode(struct plat_stmmacenet_data *plat_dat)
> +{
> +	struct starfive_dwmac *dwmac = plat_dat->bsp_priv;
> +	struct of_phandle_args args;
> +	struct regmap *regmap;
> +	unsigned int reg, mask, mode;
> +	int err;
> +
> +	switch (plat_dat->interface) {
> +	case PHY_INTERFACE_MODE_RMII:
> +		mode = MACPHYC_PHY_INFT_RMII;
> +		break;
> +
> +	case PHY_INTERFACE_MODE_RGMII:
> +	case PHY_INTERFACE_MODE_RGMII_ID:
> +		mode = MACPHYC_PHY_INFT_RGMII;
> +		break;
> +
> +	default:
> +		dev_err(dwmac->dev, "Unsupported interface %d\n",
> +			plat_dat->interface);
> +	}

Please add a return -EINVAL;

> +
> +	err = of_parse_phandle_with_fixed_args(dwmac->dev->of_node,
> +					       "starfive,syscon", 2, 0, &args);
> +	if (err) {
> +		dev_dbg(dwmac->dev, "syscon reg not found\n");
> +		return -EINVAL;
> +	}
> +
> +	reg = args.args[0];
> +	mask = args.args[1];
> +	regmap = syscon_node_to_regmap(args.np);
> +	of_node_put(args.np);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	return regmap_update_bits(regmap, reg, mask, mode << __ffs(mask));

This is a poor device tree binding. We generally don't allow bindings
which say put value X in register Y.

Could you add a table: interface mode, reg, mask? You can then do a
simple lookup based on the interface mode? No device tree binding
needed at all?

       Andrew