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