Re: [PATCH v10 5/5] soc / drm: mediatek: Fix mediatek-drm device probing

CK Hu
2020-02-28T10:07:55Z

Hi, Enric:

On Thu, 2020-02-27 at 19:08 +0100, Enric Balletbo i Serra wrote:
> In the actual implementation the same compatible string
> "mediatek,<chip>-mmsys" is used to bind the clock drivers
> (drivers/soc/mediatek) as well as to the gpu driver
> (drivers/gpu/drm/mediatek/mtk_drm_drv.c). This ends with the problem
> that the only probed driver is the clock driver and there is no display
> at all.
>
> In any case having the same compatible string for two drivers is not
> correct and should be fixed. To fix this, and maintain backward
> compatibility, we can consider that the mmsys driver is the top-level
> entry point for the multimedia subsystem, so is not a pure clock
> controller but a system controller, and the drm driver is instantiated
> by that MMSYS driver.

Reviewed-by: CK Hu <ck.hu@mediatek.com>
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> Changes in v10:
> - Match driver data to get display routing.
>
> Changes in v9:
> - Do not move the display routing from the drm driver (CK)
>
> Changes in v8:
> - New patch introduced in this series.
>
> Changes in v7: None
>
> drivers/gpu/drm/mediatek/mtk_drm_drv.c | 31 ++++++++++++++++----------
> drivers/soc/mediatek/mtk-mmsys.c | 6 +++++
> 2 files changed, 25 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 02011d3168df..29252fc0aab7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -422,9 +422,21 @@ static const struct of_device_id mtk_ddp_comp_dt_ids[] = {
> { }
> };
>
> +static const struct of_device_id mtk_drm_of_ids[] = {
> + { .compatible = "mediatek,mt2701-mmsys",
> + .data = &mt2701_mmsys_driver_data},
> + { .compatible = "mediatek,mt2712-mmsys",
> + .data = &mt2712_mmsys_driver_data},
> + { .compatible = "mediatek,mt8173-mmsys",
> + .data = &mt8173_mmsys_driver_data},
> + { }
> +};
> +
> static int mtk_drm_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> + struct device_node *phandle = dev->parent->of_node;
> + const struct of_device_id *of_id;
> struct mtk_drm_private *private;
> struct device_node *node;
> struct component_match *match = NULL;
> @@ -443,8 +455,14 @@ static int mtk_drm_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + of_id = of_match_node(mtk_drm_of_ids, phandle);
> + if (!of_id)
> + return -ENODEV;
> +
> + private->data = of_id->data;
> +
> /* Iterate over sibling DISP function blocks */
> - for_each_child_of_node(dev->of_node->parent, node) {
> + for_each_child_of_node(phandle->parent, node) {
> const struct of_device_id *of_id;
> enum mtk_ddp_comp_type comp_type;
> int comp_id;
> @@ -576,22 +594,11 @@ static int mtk_drm_sys_resume(struct device *dev)
> static SIMPLE_DEV_PM_OPS(mtk_drm_pm_ops, mtk_drm_sys_suspend,
> mtk_drm_sys_resume);
>
> -static const struct of_device_id mtk_drm_of_ids[] = {
> - { .compatible = "mediatek,mt2701-mmsys",
> - .data = &mt2701_mmsys_driver_data},
> - { .compatible = "mediatek,mt2712-mmsys",
> - .data = &mt2712_mmsys_driver_data},
> - { .compatible = "mediatek,mt8173-mmsys",
> - .data = &mt8173_mmsys_driver_data},
> - { }
> -};
> -
> static struct platform_driver mtk_drm_platform_driver = {
> .probe = mtk_drm_probe,
> .remove = mtk_drm_remove,
> .driver = {
> .name = "mediatek-drm",
> - .of_match_table = mtk_drm_of_ids,
> .pm = &mtk_drm_pm_ops,
> },
> };
> diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
> index a8a98777064e..d99c8beb2ed2 100644
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
> @@ -377,6 +377,7 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
> const struct mtk_mmsys_driver_data *data;
> struct clk_onecell_data *clk_data;
> struct device *dev = &pdev->dev;
> + struct platform_device *drm;
> void __iomem *config_regs;
> struct resource *mem;
> int ret;
> @@ -407,6 +408,11 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + drm = platform_device_register_data(&pdev->dev, "mediatek-drm",
> + PLATFORM_DEVID_NONE, NULL, 0);
> + if (IS_ERR(drm))
> + return PTR_ERR(drm);
> +
> return 0;
> }