The documentation for drm_do_get_edid in drivers/gpu/drm/drm_edid.c states:
"As in the general case the DDC bus is accessible by the kernel at the I2C
level, drivers must make all reasonable efforts to expose it as an I2C
adapter and use drm_get_edid() instead of abusing this function."
Exposing the DDC bus as an I2C adapter is more beneficial as it can be used
for purposes other than reading the EDID such as modifying the EDID or
using the HDMI DDC pins as an I2C bus through the I2C dev interface from
userspace (e.g. i2c-tools).
Implement this for A10s.
Signed-off-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The earlier Allwinner SoCs (A10, A10s, A20, A31) have an embedded HDMI
controller.
That HDMI controller is able to do audio and CEC, but those have been left
out for now.
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Allwinner have a new "Display Engine 2.0" in their new SoCs, which comes
with mixers to do graphic processing and feed data to TCON, like the old
backends and frontends.
Add support for the mixer on Allwinner V3s SoC; it's the simplest one.
Currently a lot of functions are still missing -- more investigations
are needed to gain enough information for them.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
As sun4i-backend is now a dedicated module, add an Kconfig option for
it to make it optional, since some build may only use other engines.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
As we are going to add support for the Allwinner DE2 engine in sun4i-drm
driver, we will finally have two types of display engines -- the DE1
backend and the DE2 mixer. They both do some display blending and feed
graphics data to TCON, and is part of the "Display Engine" called by
Allwinner, so I choose to call them both "engine" here.
Abstract the engine type to a new struct with an ops struct, which contains
functions that should be called outside the engine-specified code (in
TCON, CRTC or TV Encoder code).
In order to preserve bisectability, we also switch the backend and layer
code in its own module.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The tcon provides part of the functionality of the crtc, and also
provides the device node for the output port of the crtc. To be able
to use drm_of_find_possible_crtcs(), all crtc must be initialized before
any downstream encoders. The other part of the crtc is the display
backend.
The Rockchip DRM driver does this by first binding all vops, which is
their crtc, and this step also creates the crtc objects. Then all
remaining hardware components are bound. With the Allwinner display
pipeline, we have multiple components comprising the crtc, and varying
depths of the display pipeline. Since components are added with a depth
first search of the of_graph, we can initialize the crtc object within
the tcon bind function. Since the backend precedes the tcon, and the
backends cannot be muxed or switched around, we can be sure that the
associated backend is already initialized.
This patch also moves the crtc pointer from the main drm_device data to
the tcon device data. Besides the crtc callbacks, the crtc structure is
only used within the tcon driver to signal vblank events from its
interrupt handler.
As the crtc and layer bits are now called from the tcon bits, we must
move them from the sun4i-drm module to the sun4i-tcon module to avoid
circular dependencies between the two modules. This is because sun4i-drm
also calls into sun4i-tcon.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The A33 pipeline also has a component called DRC. Even though its exact
features and programming model is not known (or documented), it needs to
be clocked for the pipeline to carry the video signal all the way.
Add a minimal driver for it that just claim the needed resources for the
pipeline to operate properly.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Some Allwinner SoCs have an IP called the TV encoder that is used to output
composite and VGA signals. In such a case, we need to use the second TCON
channel.
Add support for that TV encoder.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
One of the A10 display pipeline possible output is an RGB interface to
drive LCD panels directly. This is done through the first channel of the
TCON that will output our video signals directly.
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The Allwinner A10 and subsequent SoCs share the same display pipeline, with
variations in the number of controllers (1 or 2), or the presence or not of
some output (HDMI, TV, VGA) or not.
Add a driver with a limited set of features for now, and we will hopefully
support all of them eventually
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
