Re: [PATCH v4 4/7] soc: qcom: Make the Qualcomm UFS/SDCC ICE a dedicated driver

[Eric Biggers <ebiggers@kernel.org>]

On Mon, Mar 27, 2023 at 04:47:31PM +0300, Abel Vesa wrote:
> +	/* For now this driver only supports ICE version 3 and 4. */
> +	if (major != 3 && major != 4) {
> +		dev_warn(dev, "Unsupported ICE version: v%d.%d.%d\n",
> +			 major, minor, step);
> +		return false;
> +	}

Version 4 support was not in the original.  This ought to be mentioned in the
commit message.

> +struct qcom_ice *of_qcom_ice_get(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct qcom_ice *ice = ERR_PTR(-EPROBE_DEFER);
> +	struct device_node *node;
> +	struct resource *res;
> +	void __iomem *base;
> +
> +	if (!dev || !dev->of_node)
> +		return ERR_PTR(-ENODEV);
> +
> +	/* legacy has ice reg range in the consumer DT node */
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ice");
> +	if (res) {
> +		base = devm_ioremap_resource(&pdev->dev, res);
> +		if (IS_ERR(base))
> +			return base;
> +
> +		/* create ICE instance using consumer dev */
> +		return qcom_ice_create(pdev, base);
> +	}
> +
> +	node = of_parse_phandle(dev->of_node, "qcom,ice", 0);
> +	if (!node) {
> +		ice = NULL;
> +		goto out;
> +	}

I think a longer comment in this code explaining the legacy implementation vs.
the new implementation would be helpful.

> +	pdev = of_find_device_by_node(node);
> +	if (!pdev) {
> +		dev_err(dev, "Cannot find device node %s\n", node->name);
> +		goto out;
> +	}

It is hard to understand the return value in this case, since
'ice = ERR_PTR(-EPROBE_DEFER)' happens way above.  Maybe do:

	if (!pdev) {
		dev_err(dev, "Cannot find device node %s\n", node->name);
		ice = ERR_PTR(-EPROBE_DEFER);
		goto out;
	}
> +
> +	ice = platform_get_drvdata(pdev);
> +	if (!ice) {
> +		dev_err(dev, "Cannot get ice\n");
> +		put_device(&pdev->dev);
> +		return ERR_PTR(-ENODEV);
> +	}

Can this error message be more descriptive?

Otherwise this patch is looking good, thanks!

- Eric