Re: [PATCH v2 2/3] net: stmmac: Add glue layer for T-HEAD TH1520 SoC

[Andrew Lunn <andrew@lunn.ch>]

> +static int thead_dwmac_init(struct platform_device *pdev, void *priv)
> +{
> +	struct thead_dwmac *dwmac = priv;
> +	int ret;
> +
> +	ret = thead_dwmac_set_phy_if(dwmac->plat);
> +	if (ret)
> +		return ret;
> +
> +	ret = thead_dwmac_set_txclk_dir(dwmac->plat);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_write(dwmac->apb_regmap, GMAC_RXCLK_DELAY_CTRL,
> +			   GMAC_RXCLK_DELAY_VAL(dwmac->rx_delay));
> +	if (ret)
> +		return dev_err_probe(dwmac->dev, ret,
> +				     "failed to set GMAC RX clock delay\n");
> +
> +	ret = regmap_write(dwmac->apb_regmap, GMAC_TXCLK_DELAY_CTRL,
> +			   GMAC_TXCLK_DELAY_VAL(dwmac->tx_delay));
> +	if (ret)
> +		return dev_err_probe(dwmac->dev, ret,
> +				     "failed to set GMAC TX clock delay\n");
> +
> +	thead_dwmac_fix_speed(dwmac, SPEED_1000, 0);

Is this needed? I would expect this to be called when the PHY has link
and you know the link speed. So why set it here?

> +
> +	return thead_dwmac_enable_clk(dwmac->plat);
> +}
> +
> +static int thead_dwmac_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct stmmac_resources stmmac_res;
> +	struct plat_stmmacenet_data *plat;
> +	struct thead_dwmac *dwmac;
> +	void __iomem *apb;
> +	u32 delay;
> +	int ret;
> +
> +	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret,
> +				     "failed to get resources\n");
> +
> +	plat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
> +	if (IS_ERR(plat))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(plat),
> +				     "dt configuration failed\n");
> +
> +	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
> +	if (!dwmac)
> +		return -ENOMEM;
> +
> +	/* hardware default is 0 for the rx and tx internal clock delay */
> +	dwmac->rx_delay = 0;
> +	dwmac->tx_delay = 0;
> +
> +	/* rx and tx internal delay properties are optional */
> +	if (!of_property_read_u32(np, "thead,rx-internal-delay", &delay)) {
> +		if (delay > GMAC_RXCLK_DELAY_MASK)
> +			dev_warn(&pdev->dev,
> +				 "thead,rx-internal-delay (%u) exceeds max (%lu)\n",
> +				 delay, GMAC_RXCLK_DELAY_MASK);
> +		else
> +			dwmac->rx_delay = delay;
> +	}
> +

So you keep going, with an invalid value? It is better to use
dev_err() and return -EINVAL. The DT write will then correct their
error when the device fails to probe.

If you decide to keep this... I'm not sure these properties are
needed.

> +MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");

Please add a second author, if you have taken over this driver.

       Andrew