[PATCH v5 0/3] Add support for CH1115 Controller

["Nicolás Antinori" <nico.antinori.7@gmail.com>]

This series add support for the CH1115 Controller [1].
It is a monochrome dot matrix OLED controller that supports several
interfaces such as SPI and I2C.

This driver only supports the I2C interface, but all common parts could
easily be put into a common file to be used with other interfaces.
I only have I2C to test with.

This is the first driver I write. The work is based on the driver
located at:
- drivers/gpu/drm/sitronix/st7571-i2c.c
- drivers/gpu/drm/sitronix/st7571.c

Tested with Raspberry Pi 3b+.

Changelog:

v5:
General:
 - Patch series based on 7.3-rc1
Driver:
 - Fixed KConfig dependencies (OF and BACKLIGHT_CLASS_DEVICE)
 - Initializing baclight with backlight_properties struct
 - Moved driver from drivers/gpu/drm/chipwealth to drivers/gpu/drm/tiny
 - Fixed allocation for hwbuf if width or height are not multiple of 8.
   I was allocating less memory than needed in those cases.
 - Fixed damage rect horizontal alignment.

Note: The last two fixes listed were pointed out by Sashiko in some
occasions but when I checked them I dismissed them for false positives
because I misunderstood them.

Note 2: Sashiko keeps complaining that i2c transfers are called in
atomic_update callback stating that it is forbidden to call sleeping
functions there because we are in an atomic context. AFAIK this atomic
context is not that the kernel is in a non-sleepable state, but refers
to the DRM way of working by doing check -> commit. In fact, the driver
I based this driver (st7571) and others (ssd103x) do i2c transfer in an
atomic plane update. Am I missing something?

v4: [6]
General:
  - Patch series based in kernel v7.3-rc1
Driver:
  - Fixed nits found by Christophe JAILLET.
  - Fixed max_width and max_height in modeset to avoid having bigger
  framebuffers than resolution.

v3: [5]
- General:
  - Patch series based in kernel v7.2
- In dt-bindings:
  - Removed "chipwealth,contrast" property (added backlight_device
    support in driver's code)
  - Renamed "chipwealth,invert" -> "chipwealth,inverted"
  - Added default value to "chipwealth,offset"
  - Removed 'status = "okay"' from example
  - Indented example with 4 spaces as stated in the documentation [4]
- In driver code:
  - Added support for backlight_device
  - Replaced drm_dev_unregister with drm_dev_unplug to cover the dt
    overlay unload case
  - Executing drm shutdown operations before turning off the display
  - Checking that the width (panel-timing.hactive) and height
    (panel-timing.vactive) parameters are greater than 0

v2: [3]
- General:
  - Patch series based in kernel v7.2
- In dt-bindings:
  - Fixed linter problems
  - Replaced first_page property with offset
- In driver code:
  - Fixed dst_pitch calculation
  - Renamed file from ch1115.c to ch1115-i2c.c
  - Support flip-vertical and flip-horizontal dt properties
  - Fixed several things found by sashiko-ai

v1: [2]

[1] https://datasheet4u.com/download/1576606/CH1115.html
[2] https://lore.kernel.org/all/cover.1786110720.git.nico.antinori.7@gmail.com/
[3] https://lore.kernel.org/all/cover.1787321297.git.nico.antinori.7@gmail.com/
[4] https://docs.kernel.org/devicetree/bindings/writing-schema.html#annotated-example-schema
[5] https://lore.kernel.org/all/cover.1787973729.git.nico.antinori.7@gmail.com/
[6] https://lore.kernel.org/all/cover.1788711082.git.nico.antinori.7@gmail.com/

Nicolás Antinori (3):
  dt-bindings: display: add Chipwealth CH1115 OLED Controller
  drm/ch1115: add support for Chipwealth CH1115 OLED controller
  MAINTAINERS: add entry for Chipwealth CH1115 OLED Controller

 .../bindings/display/chipwealth,ch1115.yaml   |  81 ++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   6 +
 drivers/gpu/drm/tiny/Kconfig                  |  17 +
 drivers/gpu/drm/tiny/Makefile                 |   1 +
 drivers/gpu/drm/tiny/ch1115-i2c.c             | 895 ++++++++++++++++++
 6 files changed, 1002 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/chipwealth,ch1115.yaml
 create mode 100644 drivers/gpu/drm/tiny/ch1115-i2c.c

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2.47.3