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 */
182