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_drv.h>
  13 #include <drm/drm_gem_atomic_helper.h>
  14 #include <drm/drm_managed.h>
  15 #include <drm/drm_probe_helper.h>
  16 #include <drm/drm_simple_kms_helper.h>
  17
  18 /**
  19  * DOC: overview
  20  *
  21  * This helper library provides helpers for drivers for simple display
  22  * hardware.
  23  *
  24  * drm_simple_display_pipe_init() initializes a simple display pipeline
  25  * which has only one full-screen scanout buffer feeding one output. The
  26  * pipeline is represented by &struct drm_simple_display_pipe and binds
  27  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  28  * entity. Some flexibility for code reuse is provided through a separately
  29  * allocated &drm_connector object and supporting optional &drm_bridge
  30  * encoder drivers.
  31  *
  32  * Many drivers require only a very simple encoder that fulfills the minimum
  33  * requirements of the display pipeline and does not add additional
  34  * functionality. The function drm_simple_encoder_init() provides an
  35  * implementation of such an encoder.
  36  */
  37
  38 static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = {
  39         .destroy = drm_encoder_cleanup,
  40 };
  41
  42 /**
  43  * drm_simple_encoder_init - Initialize a preallocated encoder with
  44  *                           basic functionality.
  45  * @dev: drm device
  46  * @encoder: the encoder to initialize
  47  * @encoder_type: user visible type of the encoder
  48  *
  49  * Initialises a preallocated encoder that has no further functionality.
  50  * Settings for possible CRTC and clones are left to their initial values.
  51  * The encoder will be cleaned up automatically as part of the mode-setting
  52  * cleanup.
  53  *
  54  * The caller of drm_simple_encoder_init() is responsible for freeing
  55  * the encoder's memory after the encoder has been cleaned up. At the
  56  * moment this only works reliably if the encoder data structure is
  57  * stored in the device structure. Free the encoder's memory as part of
  58  * the device release function.
  59  *
  60  * Note: consider using drmm_simple_encoder_alloc() instead of
  61  * drm_simple_encoder_init() to let the DRM managed resource infrastructure
  62  * take care of cleanup and deallocation.
  63  *
  64  * Returns:
  65  * Zero on success, error code on failure.
  66  */
  67 int drm_simple_encoder_init(struct drm_device *dev,
  68                             struct drm_encoder *encoder,
  69                             int encoder_type)
  70 {
  71         return drm_encoder_init(dev, encoder,
  72                                 &drm_simple_encoder_funcs_cleanup,
  73                                 encoder_type, NULL);
  74 }
  75 EXPORT_SYMBOL(drm_simple_encoder_init);
  76
  77 void *__drmm_simple_encoder_alloc(struct drm_device *dev, size_t size,
  78                                   size_t offset, int encoder_type)
  79 {
  80         return __drmm_encoder_alloc(dev, size, offset, NULL, encoder_type,
  81                                     NULL);
  82 }
  83 EXPORT_SYMBOL(__drmm_simple_encoder_alloc);
  84
  85 static enum drm_mode_status
  86 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  87                                const struct drm_display_mode *mode)
  88 {
  89         struct drm_simple_display_pipe *pipe;
  90
  91         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  92         if (!pipe->funcs || !pipe->funcs->mode_valid)
  93                 /* Anything goes */
  94                 return MODE_OK;
  95
  96         return pipe->funcs->mode_valid(pipe, mode);
  97 }
  98
  99 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
 100                                      struct drm_atomic_state *state)
 101 {
 102         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 103         int ret;
 104
 105         ret = drm_atomic_helper_check_crtc_state(crtc_state, false);
 106         if (ret)
 107                 return ret;
 108
 109         return drm_atomic_add_affected_planes(state, crtc);
 110 }
 111
 112 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
 113                                        struct drm_atomic_state *state)
 114 {
 115         struct drm_plane *plane;
 116         struct drm_simple_display_pipe *pipe;
 117
 118         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 119         if (!pipe->funcs || !pipe->funcs->enable)
 120                 return;
 121
 122         plane = &pipe->plane;
 123         pipe->funcs->enable(pipe, crtc->state, plane->state);
 124 }
 125
 126 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 127                                         struct drm_atomic_state *state)
 128 {
 129         struct drm_simple_display_pipe *pipe;
 130
 131         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 132         if (!pipe->funcs || !pipe->funcs->disable)
 133                 return;
 134
 135         pipe->funcs->disable(pipe);
 136 }
 137
 138 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 139         .mode_valid = drm_simple_kms_crtc_mode_valid,
 140         .atomic_check = drm_simple_kms_crtc_check,
 141         .atomic_enable = drm_simple_kms_crtc_enable,
 142         .atomic_disable = drm_simple_kms_crtc_disable,
 143 };
 144
 145 static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
 146 {
 147         struct drm_simple_display_pipe *pipe;
 148
 149         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 150         if (!pipe->funcs || !pipe->funcs->reset_crtc)
 151                 return drm_atomic_helper_crtc_reset(crtc);
 152
 153         return pipe->funcs->reset_crtc(pipe);
 154 }
 155
 156 static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
 157 {
 158         struct drm_simple_display_pipe *pipe;
 159
 160         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 161         if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
 162                 return drm_atomic_helper_crtc_duplicate_state(crtc);
 163
 164         return pipe->funcs->duplicate_crtc_state(pipe);
 165 }
 166
 167 static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
 168 {
 169         struct drm_simple_display_pipe *pipe;
 170
 171         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 172         if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
 173                 drm_atomic_helper_crtc_destroy_state(crtc, state);
 174         else
 175                 pipe->funcs->destroy_crtc_state(pipe, state);
 176 }
 177
 178 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 179 {
 180         struct drm_simple_display_pipe *pipe;
 181
 182         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 183         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 184                 return 0;
 185
 186         return pipe->funcs->enable_vblank(pipe);
 187 }
 188
 189 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 190 {
 191         struct drm_simple_display_pipe *pipe;
 192
 193         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 194         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 195                 return;
 196
 197         pipe->funcs->disable_vblank(pipe);
 198 }
 199
 200 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 201         .reset = drm_simple_kms_crtc_reset,
 202         .destroy = drm_crtc_cleanup,
 203         .set_config = drm_atomic_helper_set_config,
 204         .page_flip = drm_atomic_helper_page_flip,
 205         .atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
 206         .atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
 207         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 208         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 209 };
 210
 211 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 212                                         struct drm_atomic_state *state)
 213 {
 214         struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
 215                                                                              plane);
 216         struct drm_simple_display_pipe *pipe;
 217         struct drm_crtc_state *crtc_state;
 218         int ret;
 219
 220         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 221         crtc_state = drm_atomic_get_new_crtc_state(state,
 222                                                    &pipe->crtc);
 223
 224         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 225                                                   DRM_PLANE_NO_SCALING,
 226                                                   DRM_PLANE_NO_SCALING,
 227                                                   false, false);
 228         if (ret)
 229                 return ret;
 230
 231         if (!plane_state->visible)
 232                 return 0;
 233
 234         if (!pipe->funcs || !pipe->funcs->check)
 235                 return 0;
 236
 237         return pipe->funcs->check(pipe, plane_state, crtc_state);
 238 }
 239
 240 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 241                                         struct drm_atomic_state *state)
 242 {
 243         struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
 244                                                                             plane);
 245         struct drm_simple_display_pipe *pipe;
 246
 247         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 248         if (!pipe->funcs || !pipe->funcs->update)
 249                 return;
 250
 251         pipe->funcs->update(pipe, old_pstate);
 252 }
 253
 254 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 255                                            struct drm_plane_state *state)
 256 {
 257         struct drm_simple_display_pipe *pipe;
 258
 259         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 260         if (!pipe->funcs || !pipe->funcs->prepare_fb) {
 261                 if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
 262                         return 0;
 263
 264                 WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
 265
 266                 return drm_gem_simple_display_pipe_prepare_fb(pipe, state);
 267         }
 268
 269         return pipe->funcs->prepare_fb(pipe, state);
 270 }
 271
 272 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 273                                             struct drm_plane_state *state)
 274 {
 275         struct drm_simple_display_pipe *pipe;
 276
 277         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 278         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 279                 return;
 280
 281         pipe->funcs->cleanup_fb(pipe, state);
 282 }
 283
 284 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 285                                                 uint32_t format,
 286                                                 uint64_t modifier)
 287 {
 288         return modifier == DRM_FORMAT_MOD_LINEAR;
 289 }
 290
 291 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 292         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 293         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 294         .atomic_check = drm_simple_kms_plane_atomic_check,
 295         .atomic_update = drm_simple_kms_plane_atomic_update,
 296 };
 297
 298 static void drm_simple_kms_plane_reset(struct drm_plane *plane)
 299 {
 300         struct drm_simple_display_pipe *pipe;
 301
 302         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 303         if (!pipe->funcs || !pipe->funcs->reset_plane)
 304                 return drm_atomic_helper_plane_reset(plane);
 305
 306         return pipe->funcs->reset_plane(pipe);
 307 }
 308
 309 static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
 310 {
 311         struct drm_simple_display_pipe *pipe;
 312
 313         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 314         if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
 315                 return drm_atomic_helper_plane_duplicate_state(plane);
 316
 317         return pipe->funcs->duplicate_plane_state(pipe);
 318 }
 319
 320 static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
 321                                                struct drm_plane_state *state)
 322 {
 323         struct drm_simple_display_pipe *pipe;
 324
 325         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 326         if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
 327                 drm_atomic_helper_plane_destroy_state(plane, state);
 328         else
 329                 pipe->funcs->destroy_plane_state(pipe, state);
 330 }
 331
 332 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 333         .update_plane           = drm_atomic_helper_update_plane,
 334         .disable_plane          = drm_atomic_helper_disable_plane,
 335         .destroy                = drm_plane_cleanup,
 336         .reset                  = drm_simple_kms_plane_reset,
 337         .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
 338         .atomic_destroy_state   = drm_simple_kms_plane_destroy_state,
 339         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 340 };
 341
 342 /**
 343  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 344  * @pipe: simple display pipe object
 345  * @bridge: bridge to attach
 346  *
 347  * Makes it possible to still use the drm_simple_display_pipe helpers when
 348  * a DRM bridge has to be used.
 349  *
 350  * Note that you probably want to initialize the pipe by passing a NULL
 351  * connector to drm_simple_display_pipe_init().
 352  *
 353  * Returns:
 354  * Zero on success, negative error code on failure.
 355  */
 356 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 357                                           struct drm_bridge *bridge)
 358 {
 359         return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
 360 }
 361 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 362
 363 /**
 364  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 365  * @dev: DRM device
 366  * @pipe: simple display pipe object to initialize
 367  * @funcs: callbacks for the display pipe (optional)
 368  * @formats: array of supported formats (DRM_FORMAT\_\*)
 369  * @format_count: number of elements in @formats
 370  * @format_modifiers: array of formats modifiers
 371  * @connector: connector to attach and register (optional)
 372  *
 373  * Sets up a display pipeline which consist of a really simple
 374  * plane-crtc-encoder pipe.
 375  *
 376  * If a connector is supplied, the pipe will be coupled with the provided
 377  * connector. You may supply a NULL connector when using drm bridges, that
 378  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 379  *
 380  * Teardown of a simple display pipe is all handled automatically by the drm
 381  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 382  * release the memory for the structure themselves.
 383  *
 384  * Returns:
 385  * Zero on success, negative error code on failure.
 386  */
 387 int drm_simple_display_pipe_init(struct drm_device *dev,
 388                         struct drm_simple_display_pipe *pipe,
 389                         const struct drm_simple_display_pipe_funcs *funcs,
 390                         const uint32_t *formats, unsigned int format_count,
 391                         const uint64_t *format_modifiers,
 392                         struct drm_connector *connector)
 393 {
 394         struct drm_encoder *encoder = &pipe->encoder;
 395         struct drm_plane *plane = &pipe->plane;
 396         struct drm_crtc *crtc = &pipe->crtc;
 397         int ret;
 398
 399         pipe->connector = connector;
 400         pipe->funcs = funcs;
 401
 402         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 403         ret = drm_universal_plane_init(dev, plane, 0,
 404                                        &drm_simple_kms_plane_funcs,
 405                                        formats, format_count,
 406                                        format_modifiers,
 407                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 408         if (ret)
 409                 return ret;
 410
 411         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 412         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 413                                         &drm_simple_kms_crtc_funcs, NULL);
 414         if (ret)
 415                 return ret;
 416
 417         encoder->possible_crtcs = drm_crtc_mask(crtc);
 418         ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
 419         if (ret || !connector)
 420                 return ret;
 421
 422         return drm_connector_attach_encoder(connector, encoder);
 423 }
 424 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 425
 426 MODULE_LICENSE("GPL");