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() for more
 104          * complex case. In case the hardware lacks vblank support entirely,
 105          * drivers can set &struct drm_crtc_state.no_vblank in
 106          * &struct drm_simple_display_pipe_funcs.check and let DRM's
 107          * atomic helper fake a vblank event.
 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          * Drivers which always have their buffers pinned should use
 120          * drm_gem_fb_simple_display_pipe_prepare_fb() for this hook.
 121          */
 122         int (*prepare_fb)(struct drm_simple_display_pipe *pipe,
 123                           struct drm_plane_state *plane_state);
 124
 125         /**
 126          * @cleanup_fb:
 127          *
 128          * Optional, called by &drm_plane_helper_funcs.cleanup_fb.  Please read
 129          * the documentation for the &drm_plane_helper_funcs.cleanup_fb hook for
 130          * more details.
 131          */
 132         void (*cleanup_fb)(struct drm_simple_display_pipe *pipe,
 133                            struct drm_plane_state *plane_state);
 134
 135         /**
 136          * @enable_vblank:
 137          *
 138          * Optional, called by &drm_crtc_funcs.enable_vblank. Please read
 139          * the documentation for the &drm_crtc_funcs.enable_vblank hook for
 140          * more details.
 141          */
 142         int (*enable_vblank)(struct drm_simple_display_pipe *pipe);
 143
 144         /**
 145          * @disable_vblank:
 146          *
 147          * Optional, called by &drm_crtc_funcs.disable_vblank. Please read
 148          * the documentation for the &drm_crtc_funcs.disable_vblank hook for
 149          * more details.
 150          */
 151         void (*disable_vblank)(struct drm_simple_display_pipe *pipe);
 152 };
 153
 154 /**
 155  * struct drm_simple_display_pipe - simple display pipeline
 156  * @crtc: CRTC control structure
 157  * @plane: Plane control structure
 158  * @encoder: Encoder control structure
 159  * @connector: Connector control structure
 160  * @funcs: Pipeline control functions (optional)
 161  *
 162  * Simple display pipeline with plane, crtc and encoder collapsed into one
 163  * entity. It should be initialized by calling drm_simple_display_pipe_init().
 164  */
 165 struct drm_simple_display_pipe {
 166         struct drm_crtc crtc;
 167         struct drm_plane plane;
 168         struct drm_encoder encoder;
 169         struct drm_connector *connector;
 170
 171         const struct drm_simple_display_pipe_funcs *funcs;
 172 };
 173
 174 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 175                                           struct drm_bridge *bridge);
 176
 177 int drm_simple_display_pipe_init(struct drm_device *dev,
 178                         struct drm_simple_display_pipe *pipe,
 179                         const struct drm_simple_display_pipe_funcs *funcs,
 180                         const uint32_t *formats, unsigned int format_count,
 181                         const uint64_t *format_modifiers,
 182                         struct drm_connector *connector);
 183
 184 int drm_simple_encoder_init(struct drm_device *dev,
 185                             struct drm_encoder *encoder,
 186                             int encoder_type);
 187
 188 #endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */