drivers/gpu/drm/drm_simple_kms_helper.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 Noralf Trønnes
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/slab.h>
   8
   9 #include <drm/drm_atomic.h>
  10 #include <drm/drm_atomic_helper.h>
  11 #include <drm/drm_plane_helper.h>
  12 #include <drm/drm_probe_helper.h>
  13 #include <drm/drm_simple_kms_helper.h>
  14
  15 /**
  16  * DOC: overview
  17  *
  18  * This helper library provides helpers for drivers for simple display
  19  * hardware.
  20  *
  21  * drm_simple_display_pipe_init() initializes a simple display pipeline
  22  * which has only one full-screen scanout buffer feeding one output. The
  23  * pipeline is represented by &struct drm_simple_display_pipe and binds
  24  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  25  * entity. Some flexibility for code reuse is provided through a separately
  26  * allocated &drm_connector object and supporting optional &drm_bridge
  27  * encoder drivers.
  28  */
  29
  30 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
  31         .destroy = drm_encoder_cleanup,
  32 };
  33
  34 static enum drm_mode_status
  35 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  36                                const struct drm_display_mode *mode)
  37 {
  38         struct drm_simple_display_pipe *pipe;
  39
  40         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  41         if (!pipe->funcs || !pipe->funcs->mode_valid)
  42                 /* Anything goes */
  43                 return MODE_OK;
  44
  45         return pipe->funcs->mode_valid(crtc, mode);
  46 }
  47
  48 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  49                                      struct drm_crtc_state *state)
  50 {
  51         bool has_primary = state->plane_mask &
  52                            drm_plane_mask(crtc->primary);
  53
  54         /* We always want to have an active plane with an active CRTC */
  55         if (has_primary != state->enable)
  56                 return -EINVAL;
  57
  58         return drm_atomic_add_affected_planes(state->state, crtc);
  59 }
  60
  61 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
  62                                        struct drm_crtc_state *old_state)
  63 {
  64         struct drm_plane *plane;
  65         struct drm_simple_display_pipe *pipe;
  66
  67         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  68         if (!pipe->funcs || !pipe->funcs->enable)
  69                 return;
  70
  71         plane = &pipe->plane;
  72         pipe->funcs->enable(pipe, crtc->state, plane->state);
  73 }
  74
  75 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
  76                                         struct drm_crtc_state *old_state)
  77 {
  78         struct drm_simple_display_pipe *pipe;
  79
  80         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  81         if (!pipe->funcs || !pipe->funcs->disable)
  82                 return;
  83
  84         pipe->funcs->disable(pipe);
  85 }
  86
  87 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  88         .mode_valid = drm_simple_kms_crtc_mode_valid,
  89         .atomic_check = drm_simple_kms_crtc_check,
  90         .atomic_enable = drm_simple_kms_crtc_enable,
  91         .atomic_disable = drm_simple_kms_crtc_disable,
  92 };
  93
  94 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
  95 {
  96         struct drm_simple_display_pipe *pipe;
  97
  98         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  99         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 100                 return 0;
 101
 102         return pipe->funcs->enable_vblank(pipe);
 103 }
 104
 105 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 106 {
 107         struct drm_simple_display_pipe *pipe;
 108
 109         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 110         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 111                 return;
 112
 113         pipe->funcs->disable_vblank(pipe);
 114 }
 115
 116 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 117         .reset = drm_atomic_helper_crtc_reset,
 118         .destroy = drm_crtc_cleanup,
 119         .set_config = drm_atomic_helper_set_config,
 120         .page_flip = drm_atomic_helper_page_flip,
 121         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 122         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 123         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 124         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 125 };
 126
 127 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 128                                         struct drm_plane_state *plane_state)
 129 {
 130         struct drm_simple_display_pipe *pipe;
 131         struct drm_crtc_state *crtc_state;
 132         int ret;
 133
 134         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 135         crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
 136                                                    &pipe->crtc);
 137
 138         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 139                                                   DRM_PLANE_HELPER_NO_SCALING,
 140                                                   DRM_PLANE_HELPER_NO_SCALING,
 141                                                   false, true);
 142         if (ret)
 143                 return ret;
 144
 145         if (!plane_state->visible)
 146                 return 0;
 147
 148         if (!pipe->funcs || !pipe->funcs->check)
 149                 return 0;
 150
 151         return pipe->funcs->check(pipe, plane_state, crtc_state);
 152 }
 153
 154 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 155                                         struct drm_plane_state *old_pstate)
 156 {
 157         struct drm_simple_display_pipe *pipe;
 158
 159         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 160         if (!pipe->funcs || !pipe->funcs->update)
 161                 return;
 162
 163         pipe->funcs->update(pipe, old_pstate);
 164 }
 165
 166 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 167                                            struct drm_plane_state *state)
 168 {
 169         struct drm_simple_display_pipe *pipe;
 170
 171         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 172         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 173                 return 0;
 174
 175         return pipe->funcs->prepare_fb(pipe, state);
 176 }
 177
 178 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 179                                             struct drm_plane_state *state)
 180 {
 181         struct drm_simple_display_pipe *pipe;
 182
 183         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 184         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 185                 return;
 186
 187         pipe->funcs->cleanup_fb(pipe, state);
 188 }
 189
 190 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 191                                                 uint32_t format,
 192                                                 uint64_t modifier)
 193 {
 194         return modifier == DRM_FORMAT_MOD_LINEAR;
 195 }
 196
 197 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 198         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 199         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 200         .atomic_check = drm_simple_kms_plane_atomic_check,
 201         .atomic_update = drm_simple_kms_plane_atomic_update,
 202 };
 203
 204 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 205         .update_plane           = drm_atomic_helper_update_plane,
 206         .disable_plane          = drm_atomic_helper_disable_plane,
 207         .destroy                = drm_plane_cleanup,
 208         .reset                  = drm_atomic_helper_plane_reset,
 209         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 210         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 211         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 212 };
 213
 214 /**
 215  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 216  * @pipe: simple display pipe object
 217  * @bridge: bridge to attach
 218  *
 219  * Makes it possible to still use the drm_simple_display_pipe helpers when
 220  * a DRM bridge has to be used.
 221  *
 222  * Note that you probably want to initialize the pipe by passing a NULL
 223  * connector to drm_simple_display_pipe_init().
 224  *
 225  * Returns:
 226  * Zero on success, negative error code on failure.
 227  */
 228 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 229                                           struct drm_bridge *bridge)
 230 {
 231         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 232 }
 233 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 234
 235 /**
 236  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 237  * @dev: DRM device
 238  * @pipe: simple display pipe object to initialize
 239  * @funcs: callbacks for the display pipe (optional)
 240  * @formats: array of supported formats (DRM_FORMAT\_\*)
 241  * @format_count: number of elements in @formats
 242  * @format_modifiers: array of formats modifiers
 243  * @connector: connector to attach and register (optional)
 244  *
 245  * Sets up a display pipeline which consist of a really simple
 246  * plane-crtc-encoder pipe.
 247  *
 248  * If a connector is supplied, the pipe will be coupled with the provided
 249  * connector. You may supply a NULL connector when using drm bridges, that
 250  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 251  *
 252  * Teardown of a simple display pipe is all handled automatically by the drm
 253  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 254  * release the memory for the structure themselves.
 255  *
 256  * Returns:
 257  * Zero on success, negative error code on failure.
 258  */
 259 int drm_simple_display_pipe_init(struct drm_device *dev,
 260                         struct drm_simple_display_pipe *pipe,
 261                         const struct drm_simple_display_pipe_funcs *funcs,
 262                         const uint32_t *formats, unsigned int format_count,
 263                         const uint64_t *format_modifiers,
 264                         struct drm_connector *connector)
 265 {
 266         struct drm_encoder *encoder = &pipe->encoder;
 267         struct drm_plane *plane = &pipe->plane;
 268         struct drm_crtc *crtc = &pipe->crtc;
 269         int ret;
 270
 271         pipe->connector = connector;
 272         pipe->funcs = funcs;
 273
 274         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 275         ret = drm_universal_plane_init(dev, plane, 0,
 276                                        &drm_simple_kms_plane_funcs,
 277                                        formats, format_count,
 278                                        format_modifiers,
 279                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 280         if (ret)
 281                 return ret;
 282
 283         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 284         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 285                                         &drm_simple_kms_crtc_funcs, NULL);
 286         if (ret)
 287                 return ret;
 288
 289         encoder->possible_crtcs = drm_crtc_mask(crtc);
 290         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 291                                DRM_MODE_ENCODER_NONE, NULL);
 292         if (ret || !connector)
 293                 return ret;
 294
 295         return drm_connector_attach_encoder(connector, encoder);
 296 }
 297 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 298
 299 MODULE_LICENSE("GPL");