sun4i/drm: engine: Add mode_set callback

This optional callback is useful for setting properties which depends
only on current mode. Such properties are width, height and interlaced
output.

These properties are currently set in update layer callback for primary
plane which is less than ideal. More about that in follow up patches,
which will migrate that code to this newly defined callback.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220424162633.12369-7-samuel@sholland.org

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: Fix build warnings in sunxi_engine.h

Fixes the following build warnings:
In file included from ../drivers/gpu/drm/sun4i/sun8i_mixer.h:18:0,
from ../drivers/gpu/drm/sun4i/sun8i_vi_scaler.h:13,
from ../drivers/gpu/drm/sun4i/sun8i_vi_scaler.c:12:
../drivers/gpu/drm/sun4i/sunxi_engine.h:36:16: warning: ‘struct drm_crtc_state’ declared inside parameter list will not be visible outside of this definition or declaration
struct drm_crtc_state *old_state);
^~~~~~~~~~~~~~
../drivers/gpu/drm/sun4i/sunxi_engine.h:53:15: warning: ‘struct drm_crtc_state’ declared inside parameter list will not be visible outside of this definition or declaration
struct drm_crtc_state *state);
^~~~~~~~~~~~~~
In file included from ../drivers/gpu/drm/sun4i/sun8i_mixer.h:18:0,
from ../drivers/gpu/drm/sun4i/sun8i_ui_scaler.h:12,
from ../drivers/gpu/drm/sun4i/sun8i_ui_scaler.c:12:
../drivers/gpu/drm/sun4i/sunxi_engine.h:36:16: warning: ‘struct drm_crtc_state’ declared inside parameter list will not be visible outside of this definition or declaration
struct drm_crtc_state *old_state);
^~~~~~~~~~~~~~
../drivers/gpu/drm/sun4i/sunxi_engine.h:53:15: warning: ‘struct drm_crtc_state’ declared inside parameter list will not be visible outside of this definition or declaration
struct drm_crtc_state *state);
^~~~~~~~~~~~~~

Fixes: 6b8562c86e24 ("drm/sun4i: engine: Create an atomic_begin
callback")
Fixes: 656e5f654903 ("drm/sun4i: engine: Add a custom crtc
atomic_check")
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180122174306.231609-1-seanpaul@chromium.org

drm/sun4i: engine: Create an atomic_begin callback

We have to implement some display engine specific behaviours in
atomic_begin. Let's add a function for that.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/44110951ae0cc13767fefc7fc1d9e2ec782d0a40.1516613040.git-series.maxime.ripard@free-electrons.com

drm/sun4i: engine: Add a VBLANK quirk callback

In some cases, the display engine needs to apply some quirks during the
VBLANK event. In the Display Engine 1.0 case for example, we can only
disable the frontend once the backend has been, which is at VBLANK.

Let's introduce a callback that can be implemented by the various engines.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7c298d43aa1500196aa5d15d7a7c0f228c7a6f3c.1516613040.git-series.maxime.ripard@free-electrons.com

drm/sun4i: engine: Add a custom crtc atomic_check

We have some restrictions on what the planes and CRTC can provide that are
tied to only one generation of display engines.

For example, on the first generation, we can only have one YUV plane or one
plane that uses the frontend output.

Let's allow our engines to provide an atomic_check callback to validate the
current configuration.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e5f5f144e5c20d348cdb29933ae876c105bec017.1516613040.git-series.maxime.ripard@free-electrons.com

drm/sun4i: backend: Document the engine operations

Our operations were missing some documentation to explain what was expected
from them.

Let's make that clearer.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fdcd8ec3ae9ecd73ef089ede5218d3a41b49be05.1516613040.git-series.maxime.ripard@free-electrons.com

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>