On Wed, 2018-07-18 at 09:27 +0200, Matthias Brugger wrote: > Hi Sean, > > On 18/07/18 04:57, Sean Wang wrote: > > On Wed, 2018-07-18 at 00:03 +0200, 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. > >> > > > > Sorry for that I should have a response earlier for the series. > > > > Some points I felt they're not exactly right and should be fixed up > > before we're moving on > > > > Currently, drm driver have a wrong reference to the dt-binding, > > "mediatek,mt2701-mmsys" or "mediatek,mt8173-mmsys", they should be all > > for the subsystem exporting clock and reset line such common resource to > > its sub-devices. Every subsystem has a similar shape. I hope mmsys > > shouldn't be an exception. > > I'm not sure if I understand what you mean. You proposed to use a platform > device [1] and now you say we should change the DTS? > Yes, my initial thought is that I would like to embed drm platform device into mmsys. It is the easiest way to solve problems caused by compatible string conflict we met here in short term. > What do you mean by "drm driver has a wrong reference to the dt-binding"? How But for long-term goal, device has to define its own dt-binding before the driver is being implemented. Currently, drm driver uses wrong compatible string, "mediatek,mt2701-mmsys" or "mediatek,mt8173-mmsys", that are owned by mmsys device [1], not by drm device. [1] https://elixir.bootlin.com/linux/v4.18-rc5/source/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt > would you want to name it and most important, what would be your approach to > have backwards compatibility to older device tree bindings? > We can use embed a platform device into mmsys for solving issue caused by the older device tree binding. But for long-term, it's neccessary to have a drm device dt-binding document allowing drm driver and its components driver to follow. > > > > DRM device needs to have its own dt-binding show how connections between > > DRM components being made and its node should be put under mmsys node. > > > In this way, it becomes easy to see how the topology of the subsystem is > > and grows, like a tree "device tree", instead of hiding the details in > > the implementation. > > > > The similar example we already did for audsys on mt2701 and mt7623 as > > below > > > > audsys: clock-controller@11220000 { > > compatible = "mediatek,mt7623-audsys", > > "mediatek,mt2701-audsys", > > "syscon"; > > ... > > > > afe: audio-controller { > > compatible = "mediatek,mt7623-audio", > > "mediatek,mt2701-audio"; > > > > ... > > }; > > }; > > > > I think this approach is not working as, due to backwards compatibility, we have > to make sure that the DRM driver gets probed with the mmsys binding. > > Regards, > Matthias > > > > > Sean > > > > > >> Signed-off-by: Matthias Brugger <mbrugger@xxxxxxxx> > >> --- > >> drivers/gpu/drm/mediatek/mtk_drm_drv.c | 18 ++++++++++++++++++ > >> drivers/gpu/drm/mediatek/mtk_drm_drv.h | 2 ++ > >> 2 files changed, 20 insertions(+) > >> > >> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > >> index dd249cf5121e..c946aea722e5 100644 > >> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > >> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > >> @@ -173,6 +173,7 @@ 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 mt8173_mmsys_driver_data = { > >> @@ -180,6 +181,7 @@ 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) > >> @@ -411,6 +413,19 @@ static int mtk_drm_probe(struct platform_device *pdev) > >> if (IS_ERR(private->config_regs)) > >> return PTR_ERR(private->config_regs); > >> > >> + 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); > >> + > >> + 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; > >> @@ -515,6 +530,9 @@ 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 86cec19193c4..200eee5de419 100644 > >> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h > >> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h > >> @@ -34,11 +34,13 @@ struct mtk_mmsys_driver_data { > >> const enum mtk_ddp_comp_id *ext_path; > >> unsigned int ext_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; > >> > > > > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
