This is an attempt at providing a DRM version of drivers/staging/fbtft. I'm sending this early before cleaning up the code hoping to get some feedback in case there are better ways to structure this.
The tinydrm module provides a very simplified view of DRM for displays that has onboard video memory and is connected through a slow bus like SPI/I2C. A driver using tinydrm has to provide a function that will be called from the dirtyfb ioctl and optionally drm_panel functions which can be used to set up the display controller and control backlight.
tinydrm also has fbdev support using fb_deferred_io which is tied in through the dirtyfb function call. A driver can use the provided deferred work code to collect dirtyfb calls and schedule display memory updates if it whishes. The various display controllers can have library modules that handles display updates. Display controllers that have a similar register interface as the MIPI DBI/DCS controllers can use the lcdreg module for register access.
struct tinydrm_device { struct drm_device *base; u32 width, height; struct drm_panel panel; [...] int (*dirtyfb)(struct drm_framebuffer *fb, void *vmem, unsigned flags, unsigned color, struct drm_clip_rect *clips, unsigned num_clips); };
+------------------------------+---------+ | | fbdev | | DRM +------+ | | | | +-------------------------------------+--+ | | | tinydrm | | | +------------------+ . . . . . . . | | | deferred work | | Display driver +---------------------+ | | Controller module | +------------------+---------------------+ | lcdreg | +----------------------------------------+ | Interface (SPI, I2C, parallel) | +----------------------------------------+
Noralf Trønnes (5): drm: Add DRM support for tiny LCD displays drm/tinydrm: Add lcd register abstraction drm/tinydrm/lcdreg: Add SPI support drm/tinydrm: Add mipi-dbi support drm/tinydrm: Add support for several Adafruit TFT displays
drivers/gpu/drm/Kconfig | 2 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/tinydrm/Kconfig | 27 + drivers/gpu/drm/tinydrm/Makefile | 8 + drivers/gpu/drm/tinydrm/adafruit-tft.c | 256 ++++++++ drivers/gpu/drm/tinydrm/core/Makefile | 8 + drivers/gpu/drm/tinydrm/core/internal.h | 43 ++ drivers/gpu/drm/tinydrm/core/tinydrm-core.c | 194 ++++++ drivers/gpu/drm/tinydrm/core/tinydrm-crtc.c | 203 ++++++ drivers/gpu/drm/tinydrm/core/tinydrm-deferred.c | 116 ++++ drivers/gpu/drm/tinydrm/core/tinydrm-fbdev.c | 345 ++++++++++ drivers/gpu/drm/tinydrm/core/tinydrm-framebuffer.c | 112 ++++ drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 97 +++ drivers/gpu/drm/tinydrm/core/tinydrm-plane.c | 50 ++ drivers/gpu/drm/tinydrm/lcdreg/Kconfig | 8 + drivers/gpu/drm/tinydrm/lcdreg/Makefile | 5 + drivers/gpu/drm/tinydrm/lcdreg/internal.h | 8 + drivers/gpu/drm/tinydrm/lcdreg/lcdreg-core.c | 190 ++++++ drivers/gpu/drm/tinydrm/lcdreg/lcdreg-debugfs.c | 281 ++++++++ drivers/gpu/drm/tinydrm/lcdreg/lcdreg-spi.c | 720 +++++++++++++++++++++ drivers/gpu/drm/tinydrm/mipi-dbi.c | 231 +++++++ include/drm/tinydrm/ili9340.h | 85 +++ include/drm/tinydrm/lcdreg-spi.h | 63 ++ include/drm/tinydrm/lcdreg.h | 126 ++++ include/drm/tinydrm/mipi-dbi.h | 24 + include/drm/tinydrm/tinydrm.h | 142 ++++ 26 files changed, 3345 insertions(+) create mode 100644 drivers/gpu/drm/tinydrm/Kconfig create mode 100644 drivers/gpu/drm/tinydrm/Makefile create mode 100644 drivers/gpu/drm/tinydrm/adafruit-tft.c create mode 100644 drivers/gpu/drm/tinydrm/core/Makefile create mode 100644 drivers/gpu/drm/tinydrm/core/internal.h create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-core.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-crtc.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-deferred.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-fbdev.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-framebuffer.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-plane.c create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/Kconfig create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/Makefile create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/internal.h create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/lcdreg-core.c create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/lcdreg-debugfs.c create mode 100644 drivers/gpu/drm/tinydrm/lcdreg/lcdreg-spi.c create mode 100644 drivers/gpu/drm/tinydrm/mipi-dbi.c create mode 100644 include/drm/tinydrm/ili9340.h create mode 100644 include/drm/tinydrm/lcdreg-spi.h create mode 100644 include/drm/tinydrm/lcdreg.h create mode 100644 include/drm/tinydrm/mipi-dbi.h create mode 100644 include/drm/tinydrm/tinydrm.h
-- 2.2.2