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
 17struct drm_simple_display_pipe;
 18
 19/**
 20 * struct drm_simple_display_pipe_funcs - helper operations for a simple
 21 *                                        display pipeline
 22 */
 23struct 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	/**
 69	 * @disable:
 70	 *
 71	 * This function should be used to disable the pipeline.
 72	 * It is called when the underlying crtc is disabled.
 73	 * This hook is optional.
 74	 */
 75	void (*disable)(struct drm_simple_display_pipe *pipe);
 76
 77	/**
 78	 * @check:
 79	 *
 80	 * This function is called in the check phase of an atomic update,
 81	 * specifically when the underlying plane is checked.
 82	 * The simple display pipeline helpers already check that the plane is
 83	 * not scaled, fills the entire visible area and is always enabled
 84	 * when the crtc is also enabled.
 85	 * This hook is optional.
 86	 *
 87	 * RETURNS:
 88	 *
 89	 * 0 on success, -EINVAL if the state or the transition can't be
 90	 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
 91	 * attempt to obtain another state object ran into a &drm_modeset_lock
 92	 * deadlock.
 93	 */
 94	int (*check)(struct drm_simple_display_pipe *pipe,
 95		     struct drm_plane_state *plane_state,
 96		     struct drm_crtc_state *crtc_state);
 97	/**
 98	 * @update:
 99	 *
100	 * This function is called when the underlying plane state is updated.
101	 * This hook is optional.
102	 *
103	 * This is the function drivers should submit the
104	 * &drm_pending_vblank_event from. Using either
105	 * drm_crtc_arm_vblank_event(), when the driver supports vblank
106	 * interrupt handling, or drm_crtc_send_vblank_event() directly in case
107	 * the hardware lacks vblank support entirely.
108	 */
109	void (*update)(struct drm_simple_display_pipe *pipe,
110		       struct drm_plane_state *old_plane_state);
111
112	/**
113	 * @prepare_fb:
114	 *
115	 * Optional, called by &drm_plane_helper_funcs.prepare_fb.  Please read
116	 * the documentation for the &drm_plane_helper_funcs.prepare_fb hook for
117	 * more details.
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 */
162struct 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
171int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
172					  struct drm_bridge *bridge);
173
174int 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 */