Re: [PATCH v5 21/34] drm/mediatek: mtk_hdmi: Move CEC device parsing in new function

[Alexandre Mergnat <amergnat@baylibre.com>]

On 13/01/2025 15:52, AngeloGioacchino Del Regno wrote:
> Move the CEC device parsing logic to a new function called
> mtk_hdmi_get_cec_dev(), and move the parsing action to the end
> of mtk_hdmi_dt_parse_pdata(), allowing to remove gotos in this
> function, reducing code size and improving readability.

Why CEC device parsing logic isn't done mtk_cec.c driver ? Then add "mtk_cec_get_dev" function to 
mtk_cec.c too. Finally, call this new function in mtk_hdmi_probe after mtk_hdmi_dt_parse_pdata().

> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>   drivers/gpu/drm/mediatek/mtk_hdmi.c | 84 ++++++++++++++---------------
>   1 file changed, 40 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> index 48c37294dcbb..eb285ec394a3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
> @@ -1367,24 +1367,16 @@ static const struct drm_bridge_funcs mtk_hdmi_bridge_funcs = {
>   	.edid_read = mtk_hdmi_bridge_edid_read,
>   };
>   
> -static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
> -				   struct platform_device *pdev)
> +static int mtk_hdmi_get_cec_dev(struct mtk_hdmi *hdmi, struct device *dev, struct device_node *np)
>   {
> -	struct device *dev = &pdev->dev;
> -	struct device_node *np = dev->of_node;
> -	struct device_node *remote, *i2c_np;
>   	struct platform_device *cec_pdev;
> -	struct regmap *regmap;
> +	struct device_node *cec_np;
>   	int ret;
>   
> -	ret = mtk_hdmi_get_all_clk(hdmi, np);
> -	if (ret)
> -		return dev_err_probe(dev, ret, "Failed to get clocks\n");
> -
>   	/* The CEC module handles HDMI hotplug detection */
>   	cec_np = of_get_compatible_child(np->parent, "mediatek,mt8173-cec");

If it's done in mtk_cec.c, the hardcoded compatible string method will be replaced by of_match_table 
(mtk_cec_of_ids), which is scalable and consistent.

>   	if (!cec_np)
> -		return dev_err_probe(dev, -EINVAL, "Failed to find CEC node\n");
> +		return dev_err_probe(dev, -ENOTSUPP, "Failed to find CEC node\n");
>   
>   	cec_pdev = of_find_device_by_node(cec_np);
>   	if (!cec_pdev) {
> @@ -1393,65 +1385,69 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
>   		return -EPROBE_DEFER;
>   	}
>   	of_node_put(cec_np);
> -	hdmi->cec_dev = &cec_pdev->dev;
>   
>   	/*
>   	 * The mediatek,syscon-hdmi property contains a phandle link to the
>   	 * MMSYS_CONFIG device and the register offset of the HDMI_SYS_CFG
>   	 * registers it contains.
>   	 */
> -	regmap = syscon_regmap_lookup_by_phandle(np, "mediatek,syscon-hdmi");
> -	ret = of_property_read_u32_index(np, "mediatek,syscon-hdmi", 1,
> -					 &hdmi->sys_offset);
> -	if (IS_ERR(regmap))
> -		ret = PTR_ERR(regmap);
> -	if (ret) {
> -		dev_err_probe(dev, ret,
> -			      "Failed to get system configuration registers\n");
> -		goto put_device;
> -	}
> -	hdmi->sys_regmap = regmap;
> +	hdmi->sys_regmap = syscon_regmap_lookup_by_phandle(np, "mediatek,syscon-hdmi");
> +	if (IS_ERR(hdmi->sys_regmap))
> +		return PTR_ERR(hdmi->sys_regmap);
> +
> +	ret = of_property_read_u32_index(np, "mediatek,syscon-hdmi", 1, &hdmi->sys_offset);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +				     "Failed to get system configuration registers\n");
> +
> +	hdmi->cec_dev = &cec_pdev->dev;
> +	return 0;
> +}
> +
> +static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
> +				   struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *remote, *i2c_np;
> +	int ret;
> +
> +	ret = mtk_hdmi_get_all_clk(hdmi, np);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get clocks\n");
>   
>   	hdmi->regs = device_node_to_regmap(dev->of_node);
> -	if (IS_ERR(hdmi->regs)) {
> -		ret = PTR_ERR(hdmi->regs);
> -		goto put_device;
> -	}
> +	if (IS_ERR(hdmi->regs))
> +		return PTR_ERR(hdmi->regs);
>   
>   	remote = of_graph_get_remote_node(np, 1, 0);
> -	if (!remote) {
> -		ret = -EINVAL;
> -		goto put_device;
> -	}
> +	if (!remote)
> +		return -EINVAL;
>   
>   	if (!of_device_is_compatible(remote, "hdmi-connector")) {
>   		hdmi->next_bridge = of_drm_find_bridge(remote);
>   		if (!hdmi->next_bridge) {
>   			dev_err(dev, "Waiting for external bridge\n");
>   			of_node_put(remote);
> -			ret = -EPROBE_DEFER;
> -			goto put_device;
> +			return -EPROBE_DEFER;
>   		}
>   	}
>   
>   	i2c_np = of_parse_phandle(remote, "ddc-i2c-bus", 0);
>   	of_node_put(remote);
> -	if (!i2c_np) {
> -		ret = dev_err_probe(dev, -EINVAL, "No ddc-i2c-bus in connector\n");
> -		goto put_device;
> -	}
> +	if (!i2c_np)
> +		return dev_err_probe(dev, -EINVAL, "No ddc-i2c-bus in connector\n");
>   
>   	hdmi->ddc_adpt = of_find_i2c_adapter_by_node(i2c_np);
>   	of_node_put(i2c_np);
> -	if (!hdmi->ddc_adpt) {
> -		ret = dev_err_probe(dev, -EINVAL, "Failed to get ddc i2c adapter by node\n");
> -		goto put_device;
> -	}
> +	if (!hdmi->ddc_adpt)
> +		return dev_err_probe(dev, -EINVAL, "Failed to get ddc i2c adapter by node\n");
> +
> +	ret = mtk_hdmi_get_cec_dev(hdmi, dev, np);
> +	if (ret)
> +		return ret;
>   
>   	return 0;
> -put_device:
> -	put_device(hdmi->cec_dev);
> -	return ret;
>   }
>   
>   /*

-- 
Regards,
Alexandre