This series adds drm_panel support to drm_mipi_dbi. This avoids having 2 drivers for the same controller, one per interface DPI/DBI. Some display controllers like the ILI9341 support both interfaces and some displays/panels make both these interfaces available.
Some info about why MIPI DBI is special: MIPI DSI (Display Serial Interface) and MIPI DPI (Display Pixel Interface) needs specialiced hardware and thus they have interface drivers for this. MIPI DBI (Display Bus Interface) on the other hand reuses existing busses like SPI/8080/6800 and in the case of SPI just reuses the exising SPI subsystem. All the panels I have seen that have onboard RAM and can receive pixels over DBI needs to initialize the controller as well. This means that both the panel driver and the interface driver needs access to the same bus device.
Changes since RFC[1]: - Instead of starting with Josef's driver[2], I've started with moving the existing ili9341 driver into drm/panel and then move over mi0283qt as well since it has a ili9341 controller. Josef can then add support for his panel to this driver. His panel can support both interface modes. - Emil mentioned that the DRM driver name is ABI so I've honoured that. - The DRM driver structure is now defined in the driver using a macro instead of doing it in drm_mipi_dbi. This is necessary for file open to take a ref on the driver module.
Another thing: Looking at drm_panel.c I couldn't find anything that pins the panel driver module while the panel is attached to the connector. Shouldn't struct drm_panel_funcs have a module owner field?
Noralf.
[1] https://patchwork.freedesktop.org/series/64398/ [2] https://patchwork.freedesktop.org/patch/316528/
Noralf Trønnes (4): drm/mipi-dbi: Support command mode panel drivers drm/tiny/ili9341: Move driver to drm/panel drm/tiny/mi0283qt: Move driver to panel-ilitek-ili9341 drm/panel/ili9341: Support DPI panels
MAINTAINERS | 16 +- drivers/gpu/drm/drm_mipi_dbi.c | 92 ++++ drivers/gpu/drm/panel/Kconfig | 13 + drivers/gpu/drm/panel/Makefile | 1 + drivers/gpu/drm/panel/panel-ilitek-ili9341.c | 469 +++++++++++++++++++ drivers/gpu/drm/tiny/Kconfig | 24 - drivers/gpu/drm/tiny/Makefile | 2 - drivers/gpu/drm/tiny/ili9341.c | 268 ----------- drivers/gpu/drm/tiny/mi0283qt.c | 294 ------------ include/drm/drm_mipi_dbi.h | 34 ++ 10 files changed, 618 insertions(+), 595 deletions(-) create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9341.c delete mode 100644 drivers/gpu/drm/tiny/ili9341.c delete mode 100644 drivers/gpu/drm/tiny/mi0283qt.c