Re: [PATCH v5 04/12] drm/mediatek: Add support for mmsys through a pdev

[CK Hu]

Hi, Matthias:

On Fri, 2018-11-16 at 13:54 +0100, matthias.bgg@xxxxxxxxxx wrote:
> From: Matthias Brugger <mbrugger@xxxxxxxx>
> 
> The MMSYS subsystem includes clocks and drm components.
> This patch adds an initailization path through a platform device
> for the clock part, so that both drivers get probed from the same
> device tree compatible.

Looks good to me except one coding style preference.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> 
> Signed-off-by: Matthias Brugger <mbrugger@xxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 23 +++++++++++++++++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 99dd612a6683..18fc761ba94f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -199,6 +199,7 @@ static const struct mtk_mmsys_driver_data mt2701_mmsys_driver_data = {
>  	.ext_path = mt2701_mtk_ddp_ext,
>  	.ext_len = ARRAY_SIZE(mt2701_mtk_ddp_ext),
>  	.shadow_register = true,
> +	.clk_drv_name = "clk-mt2701-mm",
>  };
>  
>  static const struct mtk_mmsys_driver_data mt2712_mmsys_driver_data = {
> @@ -215,6 +216,7 @@ static const struct mtk_mmsys_driver_data mt8173_mmsys_driver_data = {
>  	.main_len = ARRAY_SIZE(mt8173_mtk_ddp_main),
>  	.ext_path = mt8173_mtk_ddp_ext,
>  	.ext_len = ARRAY_SIZE(mt8173_mtk_ddp_ext),
> +	.clk_drv_name = "clk-mt8173-mm",
>  };
>  
>  static int mtk_drm_kms_init(struct drm_device *drm)
> @@ -473,6 +475,24 @@ static int mtk_drm_probe(struct platform_device *pdev)
>  	if (IS_ERR(private->config_regs))
>  		return PTR_ERR(private->config_regs);
>  
> +	/*
> +	 * For legacy reasons we need to probe the clock driver via
> +	 * a platfomr device. This is outdated and should not be used
> +	 * in newer SoCs.
> +	 */
> +	if (private->data->clk_drv_name) {
> +		private->clk_dev = platform_device_register_data(dev,
> +						private->data->clk_drv_name, -1,
> +						NULL, 0);
> +
> +		if (IS_ERR(private->clk_dev)) {
> +			pr_err("failed to register %s platform device\n",
> +						private->data->clk_drv_name);

I would like to align to the right of '('.

Regards,
CK

> +
> +			return PTR_ERR(private->clk_dev);
> +		}
> +	}
> +
>  	/* Iterate over sibling DISP function blocks */
>  	for_each_child_of_node(dev->of_node->parent, node) {
>  		const struct of_device_id *of_id;
> @@ -577,6 +597,9 @@ static int mtk_drm_remove(struct platform_device *pdev)
>  	for (i = 0; i < DDP_COMPONENT_ID_MAX; i++)
>  		of_node_put(private->comp_node[i]);
>  
> +	if (private->clk_dev)
> +		platform_device_unregister(private->clk_dev);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index ab0adbd7d4ee..515ac4cae922 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -37,11 +37,13 @@ struct mtk_mmsys_driver_data {
>  	unsigned int third_len;
>  
>  	bool shadow_register;
> +	const char *clk_drv_name;
>  };
>  
>  struct mtk_drm_private {
>  	struct drm_device *drm;
>  	struct device *dma_dev;
> +	struct platform_device *clk_dev;
>  
>  	unsigned int num_pipes;
>