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_bridge.h>
  12 #include <drm/drm_managed.h>
  13 #include <drm/drm_plane_helper.h>
  14 #include <drm/drm_probe_helper.h>
  15 #include <drm/drm_simple_kms_helper.h>
  16
  17 /**
  18  * DOC: overview
  19  *
  20  * This helper library provides helpers for drivers for simple display
  21  * hardware.
  22  *
  23  * drm_simple_display_pipe_init() initializes a simple display pipeline
  24  * which has only one full-screen scanout buffer feeding one output. The
  25  * pipeline is represented by &struct drm_simple_display_pipe and binds
  26  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  27  * entity. Some flexibility for code reuse is provided through a separately
  28  * allocated &drm_connector object and supporting optional &drm_bridge
  29  * encoder drivers.
  30  *
  31  * Many drivers require only a very simple encoder that fulfills the minimum
  32  * requirements of the display pipeline and does not add additional
  33  * functionality. The function drm_simple_encoder_init() provides an
  34  * implementation of such an encoder.
  35  */
  36
  37 static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = {
  38         .destroy = drm_encoder_cleanup,
  39 };
  40
  41 /**
  42  * drm_simple_encoder_init - Initialize a preallocated encoder with
  43  *                           basic functionality.
  44  * @dev: drm device
  45  * @encoder: the encoder to initialize
  46  * @encoder_type: user visible type of the encoder
  47  *
  48  * Initialises a preallocated encoder that has no further functionality.
  49  * Settings for possible CRTC and clones are left to their initial values.
  50  * The encoder will be cleaned up automatically as part of the mode-setting
  51  * cleanup.
  52  *
  53  * The caller of drm_simple_encoder_init() is responsible for freeing
  54  * the encoder's memory after the encoder has been cleaned up. At the
  55  * moment this only works reliably if the encoder data structure is
  56  * stored in the device structure. Free the encoder's memory as part of
  57  * the device release function.
  58  *
  59  * Note: consider using drmm_simple_encoder_alloc() instead of
  60  * drm_simple_encoder_init() to let the DRM managed resource infrastructure
  61  * take care of cleanup and deallocation.
  62  *
  63  * Returns:
  64  * Zero on success, error code on failure.
  65  */
  66 int drm_simple_encoder_init(struct drm_device *dev,
  67                             struct drm_encoder *encoder,
  68                             int encoder_type)
  69 {
  70         return drm_encoder_init(dev, encoder,
  71                                 &drm_simple_encoder_funcs_cleanup,
  72                                 encoder_type, NULL);
  73 }
  74 EXPORT_SYMBOL(drm_simple_encoder_init);
  75
  76 void *__drmm_simple_encoder_alloc(struct drm_device *dev, size_t size,
  77                                   size_t offset, int encoder_type)
  78 {
  79         return __drmm_encoder_alloc(dev, size, offset, NULL, encoder_type,
  80                                     NULL);
  81 }
  82 EXPORT_SYMBOL(__drmm_simple_encoder_alloc);
  83
  84 static enum drm_mode_status
  85 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  86                                const struct drm_display_mode *mode)
  87 {
  88         struct drm_simple_display_pipe *pipe;
  89
  90         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  91         if (!pipe->funcs || !pipe->funcs->mode_valid)
  92                 /* Anything goes */
  93                 return MODE_OK;
  94
  95         return pipe->funcs->mode_valid(pipe, mode);
  96 }
  97
  98 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  99                                      struct drm_atomic_state *state)
 100 {
 101         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 102                                                                           crtc);
 103         bool has_primary = crtc_state->plane_mask &
 104                            drm_plane_mask(crtc->primary);
 105
 106         /* We always want to have an active plane with an active CRTC */
 107         if (has_primary != crtc_state->enable)
 108                 return -EINVAL;
 109
 110         return drm_atomic_add_affected_planes(state, crtc);
 111 }
 112
 113 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
 114                                        struct drm_atomic_state *state)
 115 {
 116         struct drm_plane *plane;
 117         struct drm_simple_display_pipe *pipe;
 118
 119         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 120         if (!pipe->funcs || !pipe->funcs->enable)
 121                 return;
 122
 123         plane = &pipe->plane;
 124         pipe->funcs->enable(pipe, crtc->state, plane->state);
 125 }
 126
 127 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 128                                         struct drm_atomic_state *state)
 129 {
 130         struct drm_simple_display_pipe *pipe;
 131
 132         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 133         if (!pipe->funcs || !pipe->funcs->disable)
 134                 return;
 135
 136         pipe->funcs->disable(pipe);
 137 }
 138
 139 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 140         .mode_valid = drm_simple_kms_crtc_mode_valid,
 141         .atomic_check = drm_simple_kms_crtc_check,
 142         .atomic_enable = drm_simple_kms_crtc_enable,
 143         .atomic_disable = drm_simple_kms_crtc_disable,
 144 };
 145
 146 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 147 {
 148         struct drm_simple_display_pipe *pipe;
 149
 150         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 151         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 152                 return 0;
 153
 154         return pipe->funcs->enable_vblank(pipe);
 155 }
 156
 157 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 158 {
 159         struct drm_simple_display_pipe *pipe;
 160
 161         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 162         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 163                 return;
 164
 165         pipe->funcs->disable_vblank(pipe);
 166 }
 167
 168 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 169         .reset = drm_atomic_helper_crtc_reset,
 170         .destroy = drm_crtc_cleanup,
 171         .set_config = drm_atomic_helper_set_config,
 172         .page_flip = drm_atomic_helper_page_flip,
 173         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 174         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 175         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 176         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 177 };
 178
 179 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 180                                         struct drm_atomic_state *state)
 181 {
 182         struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
 183                                                                              plane);
 184         struct drm_simple_display_pipe *pipe;
 185         struct drm_crtc_state *crtc_state;
 186         int ret;
 187
 188         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 189         crtc_state = drm_atomic_get_new_crtc_state(state,
 190                                                    &pipe->crtc);
 191
 192         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 193                                                   DRM_PLANE_HELPER_NO_SCALING,
 194                                                   DRM_PLANE_HELPER_NO_SCALING,
 195                                                   false, true);
 196         if (ret)
 197                 return ret;
 198
 199         if (!plane_state->visible)
 200                 return 0;
 201
 202         if (!pipe->funcs || !pipe->funcs->check)
 203                 return 0;
 204
 205         return pipe->funcs->check(pipe, plane_state, crtc_state);
 206 }
 207
 208 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 209                                         struct drm_atomic_state *state)
 210 {
 211         struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
 212                                                                             plane);
 213         struct drm_simple_display_pipe *pipe;
 214
 215         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 216         if (!pipe->funcs || !pipe->funcs->update)
 217                 return;
 218
 219         pipe->funcs->update(pipe, old_pstate);
 220 }
 221
 222 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 223                                            struct drm_plane_state *state)
 224 {
 225         struct drm_simple_display_pipe *pipe;
 226
 227         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 228         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 229                 return 0;
 230
 231         return pipe->funcs->prepare_fb(pipe, state);
 232 }
 233
 234 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 235                                             struct drm_plane_state *state)
 236 {
 237         struct drm_simple_display_pipe *pipe;
 238
 239         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 240         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 241                 return;
 242
 243         pipe->funcs->cleanup_fb(pipe, state);
 244 }
 245
 246 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 247                                                 uint32_t format,
 248                                                 uint64_t modifier)
 249 {
 250         return modifier == DRM_FORMAT_MOD_LINEAR;
 251 }
 252
 253 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 254         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 255         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 256         .atomic_check = drm_simple_kms_plane_atomic_check,
 257         .atomic_update = drm_simple_kms_plane_atomic_update,
 258 };
 259
 260 static void drm_simple_kms_plane_reset(struct drm_plane *plane)
 261 {
 262         struct drm_simple_display_pipe *pipe;
 263
 264         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 265         if (!pipe->funcs || !pipe->funcs->reset_plane)
 266                 return drm_atomic_helper_plane_reset(plane);
 267
 268         return pipe->funcs->reset_plane(pipe);
 269 }
 270
 271 static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
 272 {
 273         struct drm_simple_display_pipe *pipe;
 274
 275         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 276         if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
 277                 return drm_atomic_helper_plane_duplicate_state(plane);
 278
 279         return pipe->funcs->duplicate_plane_state(pipe);
 280 }
 281
 282 static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
 283                                                struct drm_plane_state *state)
 284 {
 285         struct drm_simple_display_pipe *pipe;
 286
 287         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 288         if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
 289                 drm_atomic_helper_plane_destroy_state(plane, state);
 290         else
 291                 pipe->funcs->destroy_plane_state(pipe, state);
 292 }
 293
 294 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 295         .update_plane           = drm_atomic_helper_update_plane,
 296         .disable_plane          = drm_atomic_helper_disable_plane,
 297         .destroy                = drm_plane_cleanup,
 298         .reset                  = drm_simple_kms_plane_reset,
 299         .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
 300         .atomic_destroy_state   = drm_simple_kms_plane_destroy_state,
 301         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 302 };
 303
 304 /**
 305  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 306  * @pipe: simple display pipe object
 307  * @bridge: bridge to attach
 308  *
 309  * Makes it possible to still use the drm_simple_display_pipe helpers when
 310  * a DRM bridge has to be used.
 311  *
 312  * Note that you probably want to initialize the pipe by passing a NULL
 313  * connector to drm_simple_display_pipe_init().
 314  *
 315  * Returns:
 316  * Zero on success, negative error code on failure.
 317  */
 318 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 319                                           struct drm_bridge *bridge)
 320 {
 321         return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
 322 }
 323 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 324
 325 /**
 326  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 327  * @dev: DRM device
 328  * @pipe: simple display pipe object to initialize
 329  * @funcs: callbacks for the display pipe (optional)
 330  * @formats: array of supported formats (DRM_FORMAT\_\*)
 331  * @format_count: number of elements in @formats
 332  * @format_modifiers: array of formats modifiers
 333  * @connector: connector to attach and register (optional)
 334  *
 335  * Sets up a display pipeline which consist of a really simple
 336  * plane-crtc-encoder pipe.
 337  *
 338  * If a connector is supplied, the pipe will be coupled with the provided
 339  * connector. You may supply a NULL connector when using drm bridges, that
 340  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 341  *
 342  * Teardown of a simple display pipe is all handled automatically by the drm
 343  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 344  * release the memory for the structure themselves.
 345  *
 346  * Returns:
 347  * Zero on success, negative error code on failure.
 348  */
 349 int drm_simple_display_pipe_init(struct drm_device *dev,
 350                         struct drm_simple_display_pipe *pipe,
 351                         const struct drm_simple_display_pipe_funcs *funcs,
 352                         const uint32_t *formats, unsigned int format_count,
 353                         const uint64_t *format_modifiers,
 354                         struct drm_connector *connector)
 355 {
 356         struct drm_encoder *encoder = &pipe->encoder;
 357         struct drm_plane *plane = &pipe->plane;
 358         struct drm_crtc *crtc = &pipe->crtc;
 359         int ret;
 360
 361         pipe->connector = connector;
 362         pipe->funcs = funcs;
 363
 364         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 365         ret = drm_universal_plane_init(dev, plane, 0,
 366                                        &drm_simple_kms_plane_funcs,
 367                                        formats, format_count,
 368                                        format_modifiers,
 369                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 370         if (ret)
 371                 return ret;
 372
 373         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 374         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 375                                         &drm_simple_kms_crtc_funcs, NULL);
 376         if (ret)
 377                 return ret;
 378
 379         encoder->possible_crtcs = drm_crtc_mask(crtc);
 380         ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
 381         if (ret || !connector)
 382                 return ret;
 383
 384         return drm_connector_attach_encoder(connector, encoder);
 385 }
 386 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 387
 388 MODULE_LICENSE("GPL");