include/drm/drm_simple_kms_helper.h

   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_simple_display_pipe *pipe,
  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 */