To support multiple display pipelines, we would have multiple crtcs,
with one or more planes bound to them. Obviously having hardcoded
values for the drm_plane .possible_crtcs field is not going to work.

For primary and cursor planes, the value is set by
drm_crtc_init_with_planes. We just need to set it for overlay planes.

We also fix the value set for the RGB encoder, by referencing the
crtc set in sun4i_drv.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The current layer init code keeps a pointer to the primary plane layer
in sun4i_drv. When we eventually support multiple display pipelines,
this would force us to keep track of primary planes for all crtcs. And
these pointers only get used at bind time.

Instead, have the crtc init code iterate through the returned layers
to find the primary and cursor layers. And drop the pointer from the
sun4i_drv structure.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The number of defined planes in sun4i_layer is unknown to other parts
of the sun4i drm driver. Since the return value of sun4i_layers_init
is a list of layers, make it return 1 more empty layer as an end of
list guard value.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

sun4i_layers_init allocates an array to store pointers to newly created
layers returned by sun4i_layer_init_one(), but fails to actually store
them. But it actually returns the empty array to unsuspecting users.

Save the pointers in the array, so that they may be used later.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The assignment found in the main loop in sun4i_layers_init:

	struct sun4i_layer *layer = layers[i];

is useless as it gets overwritten by the next line:

	layer = sun4i_layer_init_one(drm, plane);

Drop the assignment.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

In sun4i_layers_init we are allocating an array of pointers to struct
sun4i_layer:

	layers = devm_kcalloc(drm->dev, ARRAY_SIZE(sun4i_backend_planes),
	                      sizeof(**layers), GFP_KERNEL);

The element size should be the size of an individual element of the
array. Change it to sizeof(*layers) to avoid wasting a lot of memory.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The planes can do more than what was previously exposed. Add support for
them.

Since we still have the issue that the primary plane cannot have any alpha
component, we will expose only the non-alpha formats in the primary
formats, and the alpha formats will be exposed in the overlays.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Even though all our planes can support the ARGB formats, the lowest plane
(ie the primary plane) cannot use the alpha component, otherwise it will
just result in the transparent area being entirely black.

Since some applications will still require the ARGB format, let's force the
format to XRGB to drop the alpha component entirely.
Signed-off-by: NMaxime 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: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>