Adding Lee Jones.
On 21/02/2020 05:39, CK Hu wrote:
Hi, Enric:
On Thu, 2020-02-20 at 18:21 +0100, Enric Balletbo i Serra wrote:
Dear all,
Those patches are intended to solve an old standing issue on some Mediatek devices (mt8173, mt2701 and mt2712) in a slightly different way to the precedent series.
Up to now both drivers, clock and drm are probed with the same device tree compatible. But only the first driver get probed, which in effect breaks graphics on those devices.
The version eight of the series tries to solve the problem with a different approach than the previous series but similar to how is solved on other Mediatek devices.
The MMSYS (Multimedia subsystem) in Mediatek SoCs has some registers to control clock gates (which is used in the clk driver) and some registers to set the routing and enable the differnet blocks of the display and MDP (Media Data Path) subsystem. On this series the clk driver is not a pure clock controller but a system controller that can provide access to the shared registers between the different drivers that need it (mediatek-drm and mediatek-mdp). And the biggest change is, that in this version, clk driver is the entry point (parent) which will trigger the probe of the corresponding mediatek-drm driver and pass its MMSYS platform data for display configuration.
When mmsys is a system controller, I prefer to place mmsys in drivers/soc/mediatek, and it share registers for clock, display, and mdp driver. This means the probe function is placed in drivers/soc/mediatek ,its display clock function, mdp clock function are placed in drivers/clk, display routing are placed in drivers/gpu/drm, and mdp routing are placed in dirvers/video.
Which sounds to me like a mfd device. Something we already tried and got a NACKed by Lee Jones: https://patchwork.kernel.org/patch/10367877/
Maybe we understand the problem better now to give more arguments why it makes sense to create a mfd here?
Regards, Matthias
Regards, CK
All this series was tested on the Acer R13 Chromebook only.
For reference, here are the links to the old discussions:
- v7: https://patchwork.kernel.org/project/linux-mediatek/list/?series=241217
- v6: https://patchwork.kernel.org/project/linux-mediatek/list/?series=213219
- v5: https://patchwork.kernel.org/project/linux-mediatek/list/?series=44063
- v4:
- v3:
- https://patchwork.kernel.org/patch/10367857/
- https://patchwork.kernel.org/patch/10367861/
- https://patchwork.kernel.org/patch/10367877/
- https://patchwork.kernel.org/patch/10367875/
- https://patchwork.kernel.org/patch/10367885/
- https://patchwork.kernel.org/patch/10367883/
- https://patchwork.kernel.org/patch/10367889/
- https://patchwork.kernel.org/patch/10367907/
- https://patchwork.kernel.org/patch/10367909/
- https://patchwork.kernel.org/patch/10367905/
- v2: No relevant discussion, see v3
- v1:
Best regards, Enric
Changes in v8:
- Be a builtin_platform_driver like other mediatek mmsys drivers.
- New patches introduced in this series.
Changes in v7:
- Add R-by from CK
- Add R-by from CK
- Fix check of return value of of_clk_get
- Fix identation
- Free clk_data->clks as well
- Get rid of private data structure
Enric Balletbo i Serra (2): drm/mediatek: Move MMSYS configuration to include/linux/platform_data clk/drm: mediatek: Fix mediatek-drm device probing
Matthias Brugger (4): drm/mediatek: Use regmap for register access drm/mediatek: Omit warning on probe defers media: mtk-mdp: Check return value of of_clk_get clk: mediatek: mt8173: Switch MMSYS to platform driver
drivers/clk/mediatek/Kconfig | 6 + drivers/clk/mediatek/Makefile | 1 + drivers/clk/mediatek/clk-mt2701-mm.c | 30 +++ drivers/clk/mediatek/clk-mt2712-mm.c | 44 +++++ drivers/clk/mediatek/clk-mt8173-mm.c | 172 ++++++++++++++++++ drivers/clk/mediatek/clk-mt8173.c | 104 ----------- drivers/gpu/drm/mediatek/mtk_disp_color.c | 5 +- drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 5 +- drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 5 +- drivers/gpu/drm/mediatek/mtk_dpi.c | 12 +- drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 4 +- drivers/gpu/drm/mediatek/mtk_drm_ddp.c | 53 +++--- drivers/gpu/drm/mediatek/mtk_drm_ddp.h | 4 +- drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 56 +----- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 113 +----------- drivers/gpu/drm/mediatek/mtk_drm_drv.h | 13 +- drivers/gpu/drm/mediatek/mtk_dsi.c | 8 +- drivers/gpu/drm/mediatek/mtk_hdmi.c | 4 +- drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 6 + include/linux/platform_data/mtk_mmsys.h | 73 ++++++++ 20 files changed, 401 insertions(+), 317 deletions(-) create mode 100644 drivers/clk/mediatek/clk-mt8173-mm.c create mode 100644 include/linux/platform_data/mtk_mmsys.h