fdb164667b
The MIPI DBI 2.0 specification (2005) lists only two pixel formats for
the Type C Interface (SPI) and that is 3-bits/pixel RGB111 with
2 options for bit layout.
For Type A and B (parallel) the following formats are listed: RGB332,
RGB444, RGB565, RGB666 and RGB888 (some have 2 options for the bit layout).
Many MIPI DBI compatible controllers support all interface types on the
same chip and often the manufacturers have chosen to provide support for
the Type A/B interface pixel formats also on the Type C interface.
Some chips provide many pixel formats with optional bit layouts over SPI,
but the most common by far are RGB565 and RGB666. So even if the
specification doesn't list these formats for the Type C interface, the
industry has chosen to include them.
The MIPI DCS specification lists the standard commands that can be sent
over the MIPI DBI interface. The set_address_mode (36h) command has one
bit in the parameter that controls RGB/BGR order:
This bit controls the RGB data latching order transferred from the
peripheral’s frame memory to the display device.
This means that each supported RGB format also has a BGR variant.
Based on this rationale document the following pixel formats describing
the bit layout going over the wire:
- RGB111 (option 1): x2r1g1b1r1g1b1 (2 pixels per byte)
- BGR111 (option 1): x2b1g1r1b1g1r1 (2 pixels per byte)
- RGB111 (option 2): x1r1g1b1x1r1g1b1 (2 pixels per byte)
- BGR111 (option 2): x1b1g1r1x1b1g1r1 (2 pixels per byte)
- RGB565: r5g6b5 (2 bytes)
- BGR565: b5g6r5 (2 bytes)
- RGB666: r6x2g6x2b6x2 (3 bytes)
- BGR666: b6x2g6x2r6x2 (3 bytes)
(x: don't care)
v2:
- Use 'default: r5g6b5' (Rob)
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240604-panel-mipi-dbi-rgb666-v4-1-d7c2bcb9b78d@tronnes.org
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.