xref: /openbmc/linux/drivers/gpu/drm/vkms/vkms_plane.c (revision 2e7c04aec86758e0adfcad4a24c86593b45807a3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  */
8 
9 #include "vkms_drv.h"
10 #include <drm/drm_plane_helper.h>
11 #include <drm/drm_atomic.h>
12 #include <drm/drm_atomic_helper.h>
13 #include <drm/drm_gem_framebuffer_helper.h>
14 
15 static struct drm_plane_state *
16 vkms_plane_duplicate_state(struct drm_plane *plane)
17 {
18 	struct vkms_plane_state *vkms_state;
19 	struct vkms_crc_data *crc_data;
20 
21 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
22 	if (!vkms_state)
23 		return NULL;
24 
25 	crc_data = kzalloc(sizeof(*crc_data), GFP_KERNEL);
26 	if (WARN_ON(!crc_data))
27 		DRM_INFO("Couldn't allocate crc_data");
28 
29 	vkms_state->crc_data = crc_data;
30 
31 	__drm_atomic_helper_plane_duplicate_state(plane,
32 						  &vkms_state->base);
33 
34 	return &vkms_state->base;
35 }
36 
37 static void vkms_plane_destroy_state(struct drm_plane *plane,
38 				     struct drm_plane_state *old_state)
39 {
40 	struct vkms_plane_state *vkms_state = to_vkms_plane_state(old_state);
41 	struct drm_crtc *crtc = vkms_state->base.crtc;
42 
43 	if (crtc) {
44 		/* dropping the reference we acquired in
45 		 * vkms_primary_plane_update()
46 		 */
47 		if (drm_framebuffer_read_refcount(&vkms_state->crc_data->fb))
48 			drm_framebuffer_put(&vkms_state->crc_data->fb);
49 	}
50 
51 	kfree(vkms_state->crc_data);
52 	vkms_state->crc_data = NULL;
53 
54 	__drm_atomic_helper_plane_destroy_state(old_state);
55 	kfree(vkms_state);
56 }
57 
58 static void vkms_plane_reset(struct drm_plane *plane)
59 {
60 	struct vkms_plane_state *vkms_state;
61 
62 	if (plane->state)
63 		vkms_plane_destroy_state(plane, plane->state);
64 
65 	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
66 	if (!vkms_state) {
67 		DRM_ERROR("Cannot allocate vkms_plane_state\n");
68 		return;
69 	}
70 
71 	plane->state = &vkms_state->base;
72 	plane->state->plane = plane;
73 }
74 
75 static const struct drm_plane_funcs vkms_plane_funcs = {
76 	.update_plane		= drm_atomic_helper_update_plane,
77 	.disable_plane		= drm_atomic_helper_disable_plane,
78 	.destroy		= drm_plane_cleanup,
79 	.reset			= vkms_plane_reset,
80 	.atomic_duplicate_state = vkms_plane_duplicate_state,
81 	.atomic_destroy_state	= vkms_plane_destroy_state,
82 };
83 
84 static void vkms_primary_plane_update(struct drm_plane *plane,
85 				      struct drm_plane_state *old_state)
86 {
87 	struct vkms_plane_state *vkms_plane_state;
88 	struct vkms_crc_data *crc_data;
89 
90 	if (!plane->state->crtc || !plane->state->fb)
91 		return;
92 
93 	vkms_plane_state = to_vkms_plane_state(plane->state);
94 	crc_data = vkms_plane_state->crc_data;
95 	memcpy(&crc_data->src, &plane->state->src, sizeof(struct drm_rect));
96 	memcpy(&crc_data->fb, plane->state->fb, sizeof(struct drm_framebuffer));
97 	drm_framebuffer_get(&crc_data->fb);
98 }
99 
100 static int vkms_plane_atomic_check(struct drm_plane *plane,
101 				   struct drm_plane_state *state)
102 {
103 	struct drm_crtc_state *crtc_state;
104 	int ret;
105 
106 	if (!state->fb | !state->crtc)
107 		return 0;
108 
109 	crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
110 	if (IS_ERR(crtc_state))
111 		return PTR_ERR(crtc_state);
112 
113 	ret = drm_atomic_helper_check_plane_state(state, crtc_state,
114 						  DRM_PLANE_HELPER_NO_SCALING,
115 						  DRM_PLANE_HELPER_NO_SCALING,
116 						  false, true);
117 	if (ret != 0)
118 		return ret;
119 
120 	/* for now primary plane must be visible and full screen */
121 	if (!state->visible)
122 		return -EINVAL;
123 
124 	return 0;
125 }
126 
127 static int vkms_prepare_fb(struct drm_plane *plane,
128 			   struct drm_plane_state *state)
129 {
130 	struct drm_gem_object *gem_obj;
131 	struct vkms_gem_object *vkms_obj;
132 	int ret;
133 
134 	if (!state->fb)
135 		return 0;
136 
137 	gem_obj = drm_gem_fb_get_obj(state->fb, 0);
138 	vkms_obj = drm_gem_to_vkms_gem(gem_obj);
139 	ret = vkms_gem_vmap(gem_obj);
140 	if (ret)
141 		DRM_ERROR("vmap failed: %d\n", ret);
142 
143 	return drm_gem_fb_prepare_fb(plane, state);
144 }
145 
146 static void vkms_cleanup_fb(struct drm_plane *plane,
147 			    struct drm_plane_state *old_state)
148 {
149 	struct drm_gem_object *gem_obj;
150 
151 	if (!old_state->fb)
152 		return;
153 
154 	gem_obj = drm_gem_fb_get_obj(old_state->fb, 0);
155 	vkms_gem_vunmap(gem_obj);
156 }
157 
158 static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
159 	.atomic_update		= vkms_primary_plane_update,
160 	.atomic_check		= vkms_plane_atomic_check,
161 	.prepare_fb		= vkms_prepare_fb,
162 	.cleanup_fb		= vkms_cleanup_fb,
163 };
164 
165 struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev)
166 {
167 	struct drm_device *dev = &vkmsdev->drm;
168 	struct drm_plane *plane;
169 	const u32 *formats;
170 	int ret, nformats;
171 
172 	plane = kzalloc(sizeof(*plane), GFP_KERNEL);
173 	if (!plane)
174 		return ERR_PTR(-ENOMEM);
175 
176 	formats = vkms_formats;
177 	nformats = ARRAY_SIZE(vkms_formats);
178 
179 	ret = drm_universal_plane_init(dev, plane, 0,
180 				       &vkms_plane_funcs,
181 				       formats, nformats,
182 				       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
183 	if (ret) {
184 		kfree(plane);
185 		return ERR_PTR(ret);
186 	}
187 
188 	drm_plane_helper_add(plane, &vkms_primary_helper_funcs);
189 
190 	return plane;
191 }
192