[v5,0/5] drm/tiny: Add MIPI DBI compatible SPI driver

Message

Noralf Trønnes Feb. 24, 2022, 3:27 p.m. UTC

Hi,

This patchset adds a driver that will work with most MIPI DBI compatible
SPI panels out there.

It can replace the SPI interface support in these drivers:

$ grep -lr MIPI_DCS drivers/staging/fbtft/ | grep -v "-" | uniq | sort
drivers/staging/fbtft/fb_hx8340bn.c
drivers/staging/fbtft/fb_hx8353d.c
drivers/staging/fbtft/fb_hx8357d.c
drivers/staging/fbtft/fb_ili9163.c
drivers/staging/fbtft/fb_ili9340.c
drivers/staging/fbtft/fb_ili9341.c
drivers/staging/fbtft/fb_ili9481.c
drivers/staging/fbtft/fb_ili9486.c
drivers/staging/fbtft/fb_s6d02a1.c
drivers/staging/fbtft/fb_st7735r.c
drivers/staging/fbtft/fb_st7789v.c
drivers/staging/fbtft/fb_tinylcd.c

Note that the MIPI DBI parallel interface supported by fbtft does not
yet exist in DRM.

Maxime gave[1] a good overview of the situation with these displays and
proposed to make a driver that works with all MIPI DBI compatible
controllers and use a firmware file to provide the controller setup for
a particular panel.

Changes since version 4:
- Add sainsmart18 to compatible items (Rob)
- Expand write-only description (Sam)
- kconfig: s/DRM_KMS_CMA_HELPER/DRM_GEM_CMA_HELPER/ (Sam)
- kconfig: Add select VIDEOMODE_HELPERS (Sam)
- kconfig: Add wiki url in the description (Sam)
- Split out and use of_get_drm_panel_display_mode()(Sam)
- Only use the first compatible to look for a firmware file since the
  binding mandates 2 compatibles.
- Make having a firmware file mandatory so we can print an error
  message if it's missing to improve the user experience. It's very
  unlikely that a controller doesn't need to be initialized and if
  it doesn't, it's possible to have a firmware file containing only
  a DCS NOP.

See wiki[2] for a script to make command firmware files.

Noralf.

[1] https://lore.kernel.org/dri-devel/20211129093946.xhp22mvdut3m67sc@houat/
[2] https://github.com/notro/panel-mipi-dbi/wiki


Noralf Trønnes (5):
  dt-bindings: display: add bindings for MIPI DBI compatible SPI panels
  drm/modes: Remove trailing whitespace
  drm/modes: Add of_get_drm_panel_display_mode()
  drm/mipi-dbi: Add driver_private member to struct mipi_dbi_dev
  drm/tiny: Add MIPI DBI compatible SPI driver

 .../display/panel/panel-mipi-dbi-spi.yaml     | 127 ++++++
 MAINTAINERS                                   |   8 +
 drivers/gpu/drm/drm_modes.c                   |  51 ++-
 drivers/gpu/drm/tiny/Kconfig                  |  15 +
 drivers/gpu/drm/tiny/Makefile                 |   1 +
 drivers/gpu/drm/tiny/panel-mipi-dbi.c         | 398 ++++++++++++++++++
 include/drm/drm_mipi_dbi.h                    |   8 +
 include/drm/drm_modes.h                       |   8 +
 8 files changed, 615 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml
 create mode 100644 drivers/gpu/drm/tiny/panel-mipi-dbi.c