1 /*
2  * Copyright (C) 2016 Noralf Trønnes
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #ifndef __LINUX_DRM_SIMPLE_KMS_HELPER_H
11 #define __LINUX_DRM_SIMPLE_KMS_HELPER_H
12 
13 #include <drm/drm_crtc.h>
14 #include <drm/drm_encoder.h>
15 #include <drm/drm_plane.h>
16 
17 struct drm_simple_display_pipe;
18 
19 /**
20  * struct drm_simple_display_pipe_funcs - helper operations for a simple
21  *                                        display pipeline
22  */
23 struct drm_simple_display_pipe_funcs {
24 	/**
25 	 * @mode_valid:
26 	 *
27 	 * This callback is used to check if a specific mode is valid in the
28 	 * crtc used in this simple display pipe. This should be implemented
29 	 * if the display pipe has some sort of restriction in the modes
30 	 * it can display. For example, a given display pipe may be responsible
31 	 * to set a clock value. If the clock can not produce all the values
32 	 * for the available modes then this callback can be used to restrict
33 	 * the number of modes to only the ones that can be displayed. Another
34 	 * reason can be bandwidth mitigation: the memory port on the display
35 	 * controller can have bandwidth limitations not allowing pixel data
36 	 * to be fetched at any rate.
37 	 *
38 	 * This hook is used by the probe helpers to filter the mode list in
39 	 * drm_helper_probe_single_connector_modes(), and it is used by the
40 	 * atomic helpers to validate modes supplied by userspace in
41 	 * drm_atomic_helper_check_modeset().
42 	 *
43 	 * This function is optional.
44 	 *
45 	 * NOTE:
46 	 *
47 	 * Since this function is both called from the check phase of an atomic
48 	 * commit, and the mode validation in the probe paths it is not allowed
49 	 * to look at anything else but the passed-in mode, and validate it
50 	 * against configuration-invariant hardware constraints.
51 	 *
52 	 * RETURNS:
53 	 *
54 	 * drm_mode_status Enum
55 	 */
56 	enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
57 					   const struct drm_display_mode *mode);
58 
59 	/**
60 	 * @enable:
61 	 *
62 	 * This function should be used to enable the pipeline.
63 	 * It is called when the underlying crtc is enabled.
64 	 * This hook is optional.
65 	 */
66 	void (*enable)(struct drm_simple_display_pipe *pipe,
67 		       struct drm_crtc_state *crtc_state,
68 		       struct drm_plane_state *plane_state);
69 	/**
70 	 * @disable:
71 	 *
72 	 * This function should be used to disable the pipeline.
73 	 * It is called when the underlying crtc is disabled.
74 	 * This hook is optional.
75 	 */
76 	void (*disable)(struct drm_simple_display_pipe *pipe);
77 
78 	/**
79 	 * @check:
80 	 *
81 	 * This function is called in the check phase of an atomic update,
82 	 * specifically when the underlying plane is checked.
83 	 * The simple display pipeline helpers already check that the plane is
84 	 * not scaled, fills the entire visible area and is always enabled
85 	 * when the crtc is also enabled.
86 	 * This hook is optional.
87 	 *
88 	 * RETURNS:
89 	 *
90 	 * 0 on success, -EINVAL if the state or the transition can't be
91 	 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
92 	 * attempt to obtain another state object ran into a &drm_modeset_lock
93 	 * deadlock.
94 	 */
95 	int (*check)(struct drm_simple_display_pipe *pipe,
96 		     struct drm_plane_state *plane_state,
97 		     struct drm_crtc_state *crtc_state);
98 	/**
99 	 * @update:
100 	 *
101 	 * This function is called when the underlying plane state is updated.
102 	 * This hook is optional.
103 	 *
104 	 * This is the function drivers should submit the
105 	 * &drm_pending_vblank_event from. Using either
106 	 * drm_crtc_arm_vblank_event(), when the driver supports vblank
107 	 * interrupt handling, or drm_crtc_send_vblank_event() directly in case
108 	 * the hardware lacks vblank support entirely.
109 	 */
110 	void (*update)(struct drm_simple_display_pipe *pipe,
111 		       struct drm_plane_state *old_plane_state);
112 
113 	/**
114 	 * @prepare_fb:
115 	 *
116 	 * Optional, called by &drm_plane_helper_funcs.prepare_fb.  Please read
117 	 * the documentation for the &drm_plane_helper_funcs.prepare_fb hook for
118 	 * more details.
119 	 *
120 	 * Drivers which always have their buffers pinned should use
121 	 * drm_gem_fb_simple_display_pipe_prepare_fb() for this hook.
122 	 */
123 	int (*prepare_fb)(struct drm_simple_display_pipe *pipe,
124 			  struct drm_plane_state *plane_state);
125 
126 	/**
127 	 * @cleanup_fb:
128 	 *
129 	 * Optional, called by &drm_plane_helper_funcs.cleanup_fb.  Please read
130 	 * the documentation for the &drm_plane_helper_funcs.cleanup_fb hook for
131 	 * more details.
132 	 */
133 	void (*cleanup_fb)(struct drm_simple_display_pipe *pipe,
134 			   struct drm_plane_state *plane_state);
135 
136 	/**
137 	 * @enable_vblank:
138 	 *
139 	 * Optional, called by &drm_crtc_funcs.enable_vblank. Please read
140 	 * the documentation for the &drm_crtc_funcs.enable_vblank hook for
141 	 * more details.
142 	 */
143 	int (*enable_vblank)(struct drm_simple_display_pipe *pipe);
144 
145 	/**
146 	 * @disable_vblank:
147 	 *
148 	 * Optional, called by &drm_crtc_funcs.disable_vblank. Please read
149 	 * the documentation for the &drm_crtc_funcs.disable_vblank hook for
150 	 * more details.
151 	 */
152 	void (*disable_vblank)(struct drm_simple_display_pipe *pipe);
153 };
154 
155 /**
156  * struct drm_simple_display_pipe - simple display pipeline
157  * @crtc: CRTC control structure
158  * @plane: Plane control structure
159  * @encoder: Encoder control structure
160  * @connector: Connector control structure
161  * @funcs: Pipeline control functions (optional)
162  *
163  * Simple display pipeline with plane, crtc and encoder collapsed into one
164  * entity. It should be initialized by calling drm_simple_display_pipe_init().
165  */
166 struct drm_simple_display_pipe {
167 	struct drm_crtc crtc;
168 	struct drm_plane plane;
169 	struct drm_encoder encoder;
170 	struct drm_connector *connector;
171 
172 	const struct drm_simple_display_pipe_funcs *funcs;
173 };
174 
175 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
176 					  struct drm_bridge *bridge);
177 
178 int drm_simple_display_pipe_init(struct drm_device *dev,
179 			struct drm_simple_display_pipe *pipe,
180 			const struct drm_simple_display_pipe_funcs *funcs,
181 			const uint32_t *formats, unsigned int format_count,
182 			const uint64_t *format_modifiers,
183 			struct drm_connector *connector);
184 
185 #endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */
186