include/drm/drm_simple_kms_helper.h

   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 */