xref: /openbmc/linux/drivers/gpu/drm/sun4i/sun4i_layer.c (revision 4da722ca19f30f7db250db808d1ab1703607a932)
1 /*
2  * Copyright (C) 2015 Free Electrons
3  * Copyright (C) 2015 NextThing Co
4  *
5  * Maxime Ripard <maxime.ripard@free-electrons.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  */
12 
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_plane_helper.h>
15 #include <drm/drmP.h>
16 
17 #include "sun4i_backend.h"
18 #include "sun4i_layer.h"
19 #include "sunxi_engine.h"
20 
21 struct sun4i_plane_desc {
22 	       enum drm_plane_type     type;
23 	       u8                      pipe;
24 	       const uint32_t          *formats;
25 	       uint32_t                nformats;
26 };
27 
28 static int sun4i_backend_layer_atomic_check(struct drm_plane *plane,
29 					    struct drm_plane_state *state)
30 {
31 	return 0;
32 }
33 
34 static void sun4i_backend_layer_atomic_disable(struct drm_plane *plane,
35 					       struct drm_plane_state *old_state)
36 {
37 	struct sun4i_layer *layer = plane_to_sun4i_layer(plane);
38 	struct sun4i_backend *backend = layer->backend;
39 
40 	sun4i_backend_layer_enable(backend, layer->id, false);
41 }
42 
43 static void sun4i_backend_layer_atomic_update(struct drm_plane *plane,
44 					      struct drm_plane_state *old_state)
45 {
46 	struct sun4i_layer *layer = plane_to_sun4i_layer(plane);
47 	struct sun4i_backend *backend = layer->backend;
48 
49 	sun4i_backend_update_layer_coord(backend, layer->id, plane);
50 	sun4i_backend_update_layer_formats(backend, layer->id, plane);
51 	sun4i_backend_update_layer_buffer(backend, layer->id, plane);
52 	sun4i_backend_layer_enable(backend, layer->id, true);
53 }
54 
55 static struct drm_plane_helper_funcs sun4i_backend_layer_helper_funcs = {
56 	.atomic_check	= sun4i_backend_layer_atomic_check,
57 	.atomic_disable	= sun4i_backend_layer_atomic_disable,
58 	.atomic_update	= sun4i_backend_layer_atomic_update,
59 };
60 
61 static const struct drm_plane_funcs sun4i_backend_layer_funcs = {
62 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
63 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
64 	.destroy		= drm_plane_cleanup,
65 	.disable_plane		= drm_atomic_helper_disable_plane,
66 	.reset			= drm_atomic_helper_plane_reset,
67 	.update_plane		= drm_atomic_helper_update_plane,
68 };
69 
70 static const uint32_t sun4i_backend_layer_formats_primary[] = {
71 	DRM_FORMAT_ARGB8888,
72 	DRM_FORMAT_RGB888,
73 	DRM_FORMAT_RGB565,
74 	DRM_FORMAT_XRGB8888,
75 };
76 
77 static const uint32_t sun4i_backend_layer_formats_overlay[] = {
78 	DRM_FORMAT_ARGB8888,
79 	DRM_FORMAT_ARGB4444,
80 	DRM_FORMAT_ARGB1555,
81 	DRM_FORMAT_RGBA5551,
82 	DRM_FORMAT_RGBA4444,
83 	DRM_FORMAT_RGB888,
84 	DRM_FORMAT_RGB565,
85 	DRM_FORMAT_XRGB8888,
86 };
87 
88 static const struct sun4i_plane_desc sun4i_backend_planes[] = {
89 	{
90 		.type = DRM_PLANE_TYPE_PRIMARY,
91 		.pipe = 0,
92 		.formats = sun4i_backend_layer_formats_primary,
93 		.nformats = ARRAY_SIZE(sun4i_backend_layer_formats_primary),
94 	},
95 	{
96 		.type = DRM_PLANE_TYPE_OVERLAY,
97 		.pipe = 1,
98 		.formats = sun4i_backend_layer_formats_overlay,
99 		.nformats = ARRAY_SIZE(sun4i_backend_layer_formats_overlay),
100 	},
101 };
102 
103 static struct sun4i_layer *sun4i_layer_init_one(struct drm_device *drm,
104 						struct sun4i_backend *backend,
105 						const struct sun4i_plane_desc *plane)
106 {
107 	struct sun4i_layer *layer;
108 	int ret;
109 
110 	layer = devm_kzalloc(drm->dev, sizeof(*layer), GFP_KERNEL);
111 	if (!layer)
112 		return ERR_PTR(-ENOMEM);
113 
114 	/* possible crtcs are set later */
115 	ret = drm_universal_plane_init(drm, &layer->plane, 0,
116 				       &sun4i_backend_layer_funcs,
117 				       plane->formats, plane->nformats,
118 				       plane->type, NULL);
119 	if (ret) {
120 		dev_err(drm->dev, "Couldn't initialize layer\n");
121 		return ERR_PTR(ret);
122 	}
123 
124 	drm_plane_helper_add(&layer->plane,
125 			     &sun4i_backend_layer_helper_funcs);
126 	layer->backend = backend;
127 
128 	return layer;
129 }
130 
131 struct drm_plane **sun4i_layers_init(struct drm_device *drm,
132 				     struct sunxi_engine *engine)
133 {
134 	struct drm_plane **planes;
135 	struct sun4i_backend *backend = engine_to_sun4i_backend(engine);
136 	int i;
137 
138 	planes = devm_kcalloc(drm->dev, ARRAY_SIZE(sun4i_backend_planes) + 1,
139 			      sizeof(*planes), GFP_KERNEL);
140 	if (!planes)
141 		return ERR_PTR(-ENOMEM);
142 
143 	/*
144 	 * The hardware is a bit unusual here.
145 	 *
146 	 * Even though it supports 4 layers, it does the composition
147 	 * in two separate steps.
148 	 *
149 	 * The first one is assigning a layer to one of its two
150 	 * pipes. If more that 1 layer is assigned to the same pipe,
151 	 * and if pixels overlaps, the pipe will take the pixel from
152 	 * the layer with the highest priority.
153 	 *
154 	 * The second step is the actual alpha blending, that takes
155 	 * the two pipes as input, and uses the eventual alpha
156 	 * component to do the transparency between the two.
157 	 *
158 	 * This two steps scenario makes us unable to guarantee a
159 	 * robust alpha blending between the 4 layers in all
160 	 * situations. So we just expose two layers, one per pipe. On
161 	 * SoCs that support it, sprites could fill the need for more
162 	 * layers.
163 	 */
164 	for (i = 0; i < ARRAY_SIZE(sun4i_backend_planes); i++) {
165 		const struct sun4i_plane_desc *plane = &sun4i_backend_planes[i];
166 		struct sun4i_layer *layer;
167 
168 		layer = sun4i_layer_init_one(drm, backend, plane);
169 		if (IS_ERR(layer)) {
170 			dev_err(drm->dev, "Couldn't initialize %s plane\n",
171 				i ? "overlay" : "primary");
172 			return ERR_CAST(layer);
173 		};
174 
175 		DRM_DEBUG_DRIVER("Assigning %s plane to pipe %d\n",
176 				 i ? "overlay" : "primary", plane->pipe);
177 		regmap_update_bits(engine->regs, SUN4I_BACKEND_ATTCTL_REG0(i),
178 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK,
179 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(plane->pipe));
180 
181 		layer->id = i;
182 		planes[i] = &layer->plane;
183 	};
184 
185 	return planes;
186 }
187