treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drm/sun4i: abstract a engine type

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>

drm/sun4i: return only planes for layers created

As we are going to add support for the Allwinner DE2 Mixer in sun4i-drm
driver, we will finally have two types of layers.

Each layer is bound to a drm_plane that is CRTC-specific, so we create
them when initializing CRTC (calling sun4i_layers_init, which will be
generalized in next patch). The drm_plane's will be used when creating
CRTC, but the CRTC initialization code do not care other properties of
the layer, so we let the sun4i_layers_init function return drm_plane's
only.

As we have no need to trace the layers after the CRTC is properly
created, we drop the layers pointer in sun4i_crtc struct.

Doing this uncouples the CRTC code from the type of layer (the
sun4i_layers_init function name is still hardcoded and will be changed
in the next patch), so that we can finally gain support for the
mixer in DE2, which has different layers.

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>

drm/sun4i: Pass pointers for associated backend and tcon into crtc init

sun4i_crtc controls the backend and tcon hardware blocks of the display
pipeline.

Pass pointers to the underlying devices into the crtc init function,
instead of trying to fetch them from the drm_device structure. This
avoids the headache of trying to figure out which devices the crtc
is actually associated with.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drm/sun4i: Add backend and tcon pointers to sun4i_crtc

sun4i_crtc controls the backend and tcon hardware blocks of the display
pipeline. Instead of doing so through the master drm structure, leave
pointers to the corresponding backend and tcon in itself.

Also drop the drm_device pointer, since it is no longer needed.

The next step forward would be to pass the pointers in through
sun4i_crtc_init as parameters. This would make it easier to support
multiple display pipelines layer on.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drm/sun4i: Move layers from sun4i_drv to sun4i_crtc

This patch moves the sun4i_layers_init call from sun4i_drv_bind to
sun4i_crtc_init, and the layers pointer from struct sun4i_drv to
struct sun4i_crtc.

The layers are bound to a specific crtc, and they are not directly
used once initiated. They are used through their included drm_plane
structures.

Moving the layers into the crtc facilitates binding them to the crtc
explicitly, by setting the corresponding bit in their .possible_crtcs
fields right after the crtc is initialized. This is done in a later
patch.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drm: Add Allwinner A10 Display Engine support

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>