1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright (C) 2016 Noralf Trønnes
4 */
5
6 #ifndef __LINUX_DRM_SIMPLE_KMS_HELPER_H
7 #define __LINUX_DRM_SIMPLE_KMS_HELPER_H
8
9 #include <drm/drm_crtc.h>
10 #include <drm/drm_encoder.h>
11 #include <drm/drm_plane.h>
12
13 struct drm_simple_display_pipe;
14
15 /**
16 * struct drm_simple_display_pipe_funcs - helper operations for a simple
17 * display pipeline
18 */
19 struct drm_simple_display_pipe_funcs {
20 /**
21 * @mode_valid:
22 *
23 * This callback is used to check if a specific mode is valid in the
24 * crtc used in this simple display pipe. This should be implemented
25 * if the display pipe has some sort of restriction in the modes
26 * it can display. For example, a given display pipe may be responsible
27 * to set a clock value. If the clock can not produce all the values
28 * for the available modes then this callback can be used to restrict
29 * the number of modes to only the ones that can be displayed. Another
30 * reason can be bandwidth mitigation: the memory port on the display
31 * controller can have bandwidth limitations not allowing pixel data
32 * to be fetched at any rate.
33 *
34 * This hook is used by the probe helpers to filter the mode list in
35 * drm_helper_probe_single_connector_modes(), and it is used by the
36 * atomic helpers to validate modes supplied by userspace in
37 * drm_atomic_helper_check_modeset().
38 *
39 * This function is optional.
40 *
41 * NOTE:
42 *
43 * Since this function is both called from the check phase of an atomic
44 * commit, and the mode validation in the probe paths it is not allowed
45 * to look at anything else but the passed-in mode, and validate it
46 * against configuration-invariant hardware constraints.
47 *
48 * RETURNS:
49 *
50 * drm_mode_status Enum
51 */
52 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
53 const struct drm_display_mode *mode);
54
55 /**
56 * @enable:
57 *
58 * This function should be used to enable the pipeline.
59 * It is called when the underlying crtc is enabled.
60 * This hook is optional.
61 */
62 void (*enable)(struct drm_simple_display_pipe *pipe,
63 struct drm_crtc_state *crtc_state,
64 struct drm_plane_state *plane_state);
65 /**
66 * @disable:
67 *
68 * This function should be used to disable the pipeline.
69 * It is called when the underlying crtc is disabled.
70 * This hook is optional.
71 */
72 void (*disable)(struct drm_simple_display_pipe *pipe);
73
74 /**
75 * @check:
76 *
77 * This function is called in the check phase of an atomic update,
78 * specifically when the underlying plane is checked.
79 * The simple display pipeline helpers already check that the plane is
80 * not scaled, fills the entire visible area and is always enabled
81 * when the crtc is also enabled.
82 * This hook is optional.
83 *
84 * RETURNS:
85 *
86 * 0 on success, -EINVAL if the state or the transition can't be
87 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
88 * attempt to obtain another state object ran into a &drm_modeset_lock
89 * deadlock.
90 */
91 int (*check)(struct drm_simple_display_pipe *pipe,
92 struct drm_plane_state *plane_state,
93 struct drm_crtc_state *crtc_state);
94 /**
95 * @update:
96 *
97 * This function is called when the underlying plane state is updated.
98 * This hook is optional.
99 *
100 * This is the function drivers should submit the
101 * &drm_pending_vblank_event from. Using either
102 * drm_crtc_arm_vblank_event(), when the driver supports vblank
103 * interrupt handling, or drm_crtc_send_vblank_event() directly in case
104 * the hardware lacks vblank support entirely.
105 */
106 void (*update)(struct drm_simple_display_pipe *pipe,
107 struct drm_plane_state *old_plane_state);
108
109 /**
110 * @prepare_fb:
111 *
112 * Optional, called by &drm_plane_helper_funcs.prepare_fb. Please read
113 * the documentation for the &drm_plane_helper_funcs.prepare_fb hook for
114 * more details.
115 *
116 * Drivers which always have their buffers pinned should use
117 * drm_gem_fb_simple_display_pipe_prepare_fb() for this hook.
118 */
119 int (*prepare_fb)(struct drm_simple_display_pipe *pipe,
120 struct drm_plane_state *plane_state);
121
122 /**
123 * @cleanup_fb:
124 *
125 * Optional, called by &drm_plane_helper_funcs.cleanup_fb. Please read
126 * the documentation for the &drm_plane_helper_funcs.cleanup_fb hook for
127 * more details.
128 */
129 void (*cleanup_fb)(struct drm_simple_display_pipe *pipe,
130 struct drm_plane_state *plane_state);
131
132 /**
133 * @enable_vblank:
134 *
135 * Optional, called by &drm_crtc_funcs.enable_vblank. Please read
136 * the documentation for the &drm_crtc_funcs.enable_vblank hook for
137 * more details.
138 */
139 int (*enable_vblank)(struct drm_simple_display_pipe *pipe);
140
141 /**
142 * @disable_vblank:
143 *
144 * Optional, called by &drm_crtc_funcs.disable_vblank. Please read
145 * the documentation for the &drm_crtc_funcs.disable_vblank hook for
146 * more details.
147 */
148 void (*disable_vblank)(struct drm_simple_display_pipe *pipe);
149 };
150
151 /**
152 * struct drm_simple_display_pipe - simple display pipeline
153 * @crtc: CRTC control structure
154 * @plane: Plane control structure
155 * @encoder: Encoder control structure
156 * @connector: Connector control structure
157 * @funcs: Pipeline control functions (optional)
158 *
159 * Simple display pipeline with plane, crtc and encoder collapsed into one
160 * entity. It should be initialized by calling drm_simple_display_pipe_init().
161 */
162 struct drm_simple_display_pipe {
163 struct drm_crtc crtc;
164 struct drm_plane plane;
165 struct drm_encoder encoder;
166 struct drm_connector *connector;
167
168 const struct drm_simple_display_pipe_funcs *funcs;
169 };
170
171 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
172 struct drm_bridge *bridge);
173
174 int drm_simple_display_pipe_init(struct drm_device *dev,
175 struct drm_simple_display_pipe *pipe,
176 const struct drm_simple_display_pipe_funcs *funcs,
177 const uint32_t *formats, unsigned int format_count,
178 const uint64_t *format_modifiers,
179 struct drm_connector *connector);
180
181 #endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */