drm/ssd130x: Add support for the SSD132x OLED controller family

The Solomon SSD132x controllers (such as the SSD1322, SSD1325 and SSD1327)
are used by 16 grayscale dot matrix OLED panels, extend the driver to also
support this chip family.

Instead adding an indirection level to allow the same modesetting pipeline
to be used by both controller families, add another pipeline for SSD132x.

This leads to some code duplication but it makes the driver easier to read
and reason about. Once other controller families are added (e.g: SSD133x),
some common code can be factored out in driver helpers to be shared by the
different families. But that can be done later once these patterns emerge.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231014071520.1342189-5-javierm@redhat.com

drm/solomon: Add SSD130x OLED displays SPI support

The ssd130x driver only provides the core support for these devices but it
does not have any bus transport logic. Add a driver to interface over SPI.

There is a difference in the communication protocol when using 4-wire SPI
instead of I2C. For the latter, a control byte that contains a D/C# field
has to be sent. This field tells the controller whether the data has to be
written to the command register or to the graphics display data memory.

But for 4-wire SPI that control byte is not used, instead a real D/C# line
must be pulled HIGH for commands data and LOW for graphics display data.

For this reason the standard SPI regmap can't be used and a custom .write
bus handler is needed.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patchwork.freedesktop.org/patch/msgid/20220419214824.335075-6-javierm@redhat.com

drm/ssd130x: Add support for SINO WEALTH SH1106

The SINO WEALTH SH1106 is an OLED display driver that is somewhat
compatible with the SSD1306. It supports a slightly wider display,
at 132 instead of 128 pixels. The basic commands are the same, but
the SH1106 doesn't support the horizontal or vertical address modes.

Add support for this display driver. The default values for some of
the hardware settings are taken from the datasheet.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220406172956.3953-5-wens@kernel.org

drm/solomon: Make DRM_SSD130X depends on MMU

WARNING: unmet direct dependencies detected for DRM_GEM_SHMEM_HELPER
Depends on [n]: HAS_IOMEM [=y] && DRM [=m] && MMU [=n]
Selected by [m]:
- DRM_SSD130X [=m] && HAS_IOMEM [=y] && DRM [=m]

DRM_GEM_SHMEM_HELPER depends on MMU, DRM_SSD130X should also depends on MMU.

Fixes: a61732e80867 ("drm: Add driver for Solomon SSD130x OLED displays")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220312063437.19160-1-yuehaibing@huawei.com

drm/solomon: Add SSD130x OLED displays I2C support

The ssd130x driver only provides the core support for these devices but it
does not have any bus transport logic. Add a driver to interface over I2C.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-5-javierm@redhat.com

drm: Add driver for Solomon SSD130x OLED displays

This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
OLED display controllers.

It's only the core part of the driver and a bus specific driver is needed
for each transport interface supported by the display controllers.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220214133710.3278506-4-javierm@redhat.com