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_crtc.h>
15 #include <drm/drm_plane_helper.h>
16 #include <drm/drmP.h>
17 
18 #include "sun4i_backend.h"
19 #include "sun4i_drv.h"
20 #include "sun4i_layer.h"
21 
22 struct sun4i_plane_desc {
23 	       enum drm_plane_type     type;
24 	       u8                      pipe;
25 	       const uint32_t          *formats;
26 	       uint32_t                nformats;
27 };
28 
29 static int sun4i_backend_layer_atomic_check(struct drm_plane *plane,
30 					    struct drm_plane_state *state)
31 {
32 	return 0;
33 }
34 
35 static void sun4i_backend_layer_atomic_disable(struct drm_plane *plane,
36 					       struct drm_plane_state *old_state)
37 {
38 	struct sun4i_layer *layer = plane_to_sun4i_layer(plane);
39 	struct sun4i_drv *drv = layer->drv;
40 	struct sun4i_backend *backend = drv->backend;
41 
42 	sun4i_backend_layer_enable(backend, layer->id, false);
43 }
44 
45 static void sun4i_backend_layer_atomic_update(struct drm_plane *plane,
46 					      struct drm_plane_state *old_state)
47 {
48 	struct sun4i_layer *layer = plane_to_sun4i_layer(plane);
49 	struct sun4i_drv *drv = layer->drv;
50 	struct sun4i_backend *backend = drv->backend;
51 
52 	sun4i_backend_update_layer_coord(backend, layer->id, plane);
53 	sun4i_backend_update_layer_formats(backend, layer->id, plane);
54 	sun4i_backend_update_layer_buffer(backend, layer->id, plane);
55 	sun4i_backend_layer_enable(backend, layer->id, true);
56 }
57 
58 static struct drm_plane_helper_funcs sun4i_backend_layer_helper_funcs = {
59 	.atomic_check	= sun4i_backend_layer_atomic_check,
60 	.atomic_disable	= sun4i_backend_layer_atomic_disable,
61 	.atomic_update	= sun4i_backend_layer_atomic_update,
62 };
63 
64 static const struct drm_plane_funcs sun4i_backend_layer_funcs = {
65 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
66 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
67 	.destroy		= drm_plane_cleanup,
68 	.disable_plane		= drm_atomic_helper_disable_plane,
69 	.reset			= drm_atomic_helper_plane_reset,
70 	.update_plane		= drm_atomic_helper_update_plane,
71 };
72 
73 static const uint32_t sun4i_backend_layer_formats_primary[] = {
74 	DRM_FORMAT_ARGB8888,
75 	DRM_FORMAT_RGB888,
76 	DRM_FORMAT_RGB565,
77 	DRM_FORMAT_XRGB8888,
78 };
79 
80 static const uint32_t sun4i_backend_layer_formats_overlay[] = {
81 	DRM_FORMAT_ARGB8888,
82 	DRM_FORMAT_ARGB4444,
83 	DRM_FORMAT_ARGB1555,
84 	DRM_FORMAT_RGBA5551,
85 	DRM_FORMAT_RGBA4444,
86 	DRM_FORMAT_RGB888,
87 	DRM_FORMAT_RGB565,
88 	DRM_FORMAT_XRGB8888,
89 };
90 
91 static const struct sun4i_plane_desc sun4i_backend_planes[] = {
92 	{
93 		.type = DRM_PLANE_TYPE_PRIMARY,
94 		.pipe = 0,
95 		.formats = sun4i_backend_layer_formats_primary,
96 		.nformats = ARRAY_SIZE(sun4i_backend_layer_formats_primary),
97 	},
98 	{
99 		.type = DRM_PLANE_TYPE_OVERLAY,
100 		.pipe = 1,
101 		.formats = sun4i_backend_layer_formats_overlay,
102 		.nformats = ARRAY_SIZE(sun4i_backend_layer_formats_overlay),
103 	},
104 };
105 
106 static struct sun4i_layer *sun4i_layer_init_one(struct drm_device *drm,
107 						const struct sun4i_plane_desc *plane)
108 {
109 	struct sun4i_drv *drv = drm->dev_private;
110 	struct sun4i_layer *layer;
111 	int ret;
112 
113 	layer = devm_kzalloc(drm->dev, sizeof(*layer), GFP_KERNEL);
114 	if (!layer)
115 		return ERR_PTR(-ENOMEM);
116 
117 	ret = drm_universal_plane_init(drm, &layer->plane, BIT(0),
118 				       &sun4i_backend_layer_funcs,
119 				       plane->formats, plane->nformats,
120 				       plane->type, NULL);
121 	if (ret) {
122 		dev_err(drm->dev, "Couldn't initialize layer\n");
123 		return ERR_PTR(ret);
124 	}
125 
126 	drm_plane_helper_add(&layer->plane,
127 			     &sun4i_backend_layer_helper_funcs);
128 	layer->drv = drv;
129 
130 	if (plane->type == DRM_PLANE_TYPE_PRIMARY)
131 		drv->primary = &layer->plane;
132 
133 	return layer;
134 }
135 
136 struct sun4i_layer **sun4i_layers_init(struct drm_device *drm)
137 {
138 	struct sun4i_drv *drv = drm->dev_private;
139 	struct sun4i_layer **layers;
140 	int i;
141 
142 	layers = devm_kcalloc(drm->dev, ARRAY_SIZE(sun4i_backend_planes),
143 			      sizeof(**layers), GFP_KERNEL);
144 	if (!layers)
145 		return ERR_PTR(-ENOMEM);
146 
147 	/*
148 	 * The hardware is a bit unusual here.
149 	 *
150 	 * Even though it supports 4 layers, it does the composition
151 	 * in two separate steps.
152 	 *
153 	 * The first one is assigning a layer to one of its two
154 	 * pipes. If more that 1 layer is assigned to the same pipe,
155 	 * and if pixels overlaps, the pipe will take the pixel from
156 	 * the layer with the highest priority.
157 	 *
158 	 * The second step is the actual alpha blending, that takes
159 	 * the two pipes as input, and uses the eventual alpha
160 	 * component to do the transparency between the two.
161 	 *
162 	 * This two steps scenario makes us unable to guarantee a
163 	 * robust alpha blending between the 4 layers in all
164 	 * situations. So we just expose two layers, one per pipe. On
165 	 * SoCs that support it, sprites could fill the need for more
166 	 * layers.
167 	 */
168 	for (i = 0; i < ARRAY_SIZE(sun4i_backend_planes); i++) {
169 		const struct sun4i_plane_desc *plane = &sun4i_backend_planes[i];
170 		struct sun4i_layer *layer = layers[i];
171 
172 		layer = sun4i_layer_init_one(drm, plane);
173 		if (IS_ERR(layer)) {
174 			dev_err(drm->dev, "Couldn't initialize %s plane\n",
175 				i ? "overlay" : "primary");
176 			return ERR_CAST(layer);
177 		};
178 
179 		DRM_DEBUG_DRIVER("Assigning %s plane to pipe %d\n",
180 				 i ? "overlay" : "primary", plane->pipe);
181 		regmap_update_bits(drv->backend->regs, SUN4I_BACKEND_ATTCTL_REG0(i),
182 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK,
183 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(plane->pipe));
184 
185 		layer->id = i;
186 	};
187 
188 	return layers;
189 }
190