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,
 104                                                                           crtc);
 105         bool has_primary = crtc_state->plane_mask &
 106                            drm_plane_mask(crtc->primary);
 107
 108         /* We always want to have an active plane with an active CRTC */
 109         if (has_primary != crtc_state->enable)
 110                 return -EINVAL;
 111
 112         return drm_atomic_add_affected_planes(state, crtc);
 113 }
 114
 115 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
 116                                        struct drm_atomic_state *state)
 117 {
 118         struct drm_plane *plane;
 119         struct drm_simple_display_pipe *pipe;
 120
 121         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 122         if (!pipe->funcs || !pipe->funcs->enable)
 123                 return;
 124
 125         plane = &pipe->plane;
 126         pipe->funcs->enable(pipe, crtc->state, plane->state);
 127 }
 128
 129 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 130                                         struct drm_atomic_state *state)
 131 {
 132         struct drm_simple_display_pipe *pipe;
 133
 134         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 135         if (!pipe->funcs || !pipe->funcs->disable)
 136                 return;
 137
 138         pipe->funcs->disable(pipe);
 139 }
 140
 141 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 142         .mode_valid = drm_simple_kms_crtc_mode_valid,
 143         .atomic_check = drm_simple_kms_crtc_check,
 144         .atomic_enable = drm_simple_kms_crtc_enable,
 145         .atomic_disable = drm_simple_kms_crtc_disable,
 146 };
 147
 148 static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
 149 {
 150         struct drm_simple_display_pipe *pipe;
 151
 152         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 153         if (!pipe->funcs || !pipe->funcs->reset_crtc)
 154                 return drm_atomic_helper_crtc_reset(crtc);
 155
 156         return pipe->funcs->reset_crtc(pipe);
 157 }
 158
 159 static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
 160 {
 161         struct drm_simple_display_pipe *pipe;
 162
 163         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 164         if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
 165                 return drm_atomic_helper_crtc_duplicate_state(crtc);
 166
 167         return pipe->funcs->duplicate_crtc_state(pipe);
 168 }
 169
 170 static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
 171 {
 172         struct drm_simple_display_pipe *pipe;
 173
 174         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 175         if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
 176                 drm_atomic_helper_crtc_destroy_state(crtc, state);
 177         else
 178                 pipe->funcs->destroy_crtc_state(pipe, state);
 179 }
 180
 181 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 182 {
 183         struct drm_simple_display_pipe *pipe;
 184
 185         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 186         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 187                 return 0;
 188
 189         return pipe->funcs->enable_vblank(pipe);
 190 }
 191
 192 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 193 {
 194         struct drm_simple_display_pipe *pipe;
 195
 196         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 197         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 198                 return;
 199
 200         pipe->funcs->disable_vblank(pipe);
 201 }
 202
 203 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 204         .reset = drm_simple_kms_crtc_reset,
 205         .destroy = drm_crtc_cleanup,
 206         .set_config = drm_atomic_helper_set_config,
 207         .page_flip = drm_atomic_helper_page_flip,
 208         .atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
 209         .atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
 210         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 211         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 212 };
 213
 214 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 215                                         struct drm_atomic_state *state)
 216 {
 217         struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
 218                                                                              plane);
 219         struct drm_simple_display_pipe *pipe;
 220         struct drm_crtc_state *crtc_state;
 221         int ret;
 222
 223         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 224         crtc_state = drm_atomic_get_new_crtc_state(state,
 225                                                    &pipe->crtc);
 226
 227         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 228                                                   DRM_PLANE_HELPER_NO_SCALING,
 229                                                   DRM_PLANE_HELPER_NO_SCALING,
 230                                                   false, true);
 231         if (ret)
 232                 return ret;
 233
 234         if (!plane_state->visible)
 235                 return 0;
 236
 237         if (!pipe->funcs || !pipe->funcs->check)
 238                 return 0;
 239
 240         return pipe->funcs->check(pipe, plane_state, crtc_state);
 241 }
 242
 243 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 244                                         struct drm_atomic_state *state)
 245 {
 246         struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
 247                                                                             plane);
 248         struct drm_simple_display_pipe *pipe;
 249
 250         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 251         if (!pipe->funcs || !pipe->funcs->update)
 252                 return;
 253
 254         pipe->funcs->update(pipe, old_pstate);
 255 }
 256
 257 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 258                                            struct drm_plane_state *state)
 259 {
 260         struct drm_simple_display_pipe *pipe;
 261
 262         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 263         if (!pipe->funcs || !pipe->funcs->prepare_fb) {
 264                 if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
 265                         return 0;
 266
 267                 WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
 268
 269                 return drm_gem_simple_display_pipe_prepare_fb(pipe, state);
 270         }
 271
 272         return pipe->funcs->prepare_fb(pipe, state);
 273 }
 274
 275 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 276                                             struct drm_plane_state *state)
 277 {
 278         struct drm_simple_display_pipe *pipe;
 279
 280         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 281         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 282                 return;
 283
 284         pipe->funcs->cleanup_fb(pipe, state);
 285 }
 286
 287 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 288                                                 uint32_t format,
 289                                                 uint64_t modifier)
 290 {
 291         return modifier == DRM_FORMAT_MOD_LINEAR;
 292 }
 293
 294 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 295         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 296         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 297         .atomic_check = drm_simple_kms_plane_atomic_check,
 298         .atomic_update = drm_simple_kms_plane_atomic_update,
 299 };
 300
 301 static void drm_simple_kms_plane_reset(struct drm_plane *plane)
 302 {
 303         struct drm_simple_display_pipe *pipe;
 304
 305         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 306         if (!pipe->funcs || !pipe->funcs->reset_plane)
 307                 return drm_atomic_helper_plane_reset(plane);
 308
 309         return pipe->funcs->reset_plane(pipe);
 310 }
 311
 312 static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
 313 {
 314         struct drm_simple_display_pipe *pipe;
 315
 316         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 317         if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
 318                 return drm_atomic_helper_plane_duplicate_state(plane);
 319
 320         return pipe->funcs->duplicate_plane_state(pipe);
 321 }
 322
 323 static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
 324                                                struct drm_plane_state *state)
 325 {
 326         struct drm_simple_display_pipe *pipe;
 327
 328         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 329         if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
 330                 drm_atomic_helper_plane_destroy_state(plane, state);
 331         else
 332                 pipe->funcs->destroy_plane_state(pipe, state);
 333 }
 334
 335 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 336         .update_plane           = drm_atomic_helper_update_plane,
 337         .disable_plane          = drm_atomic_helper_disable_plane,
 338         .destroy                = drm_plane_cleanup,
 339         .reset                  = drm_simple_kms_plane_reset,
 340         .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
 341         .atomic_destroy_state   = drm_simple_kms_plane_destroy_state,
 342         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 343 };
 344
 345 /**
 346  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 347  * @pipe: simple display pipe object
 348  * @bridge: bridge to attach
 349  *
 350  * Makes it possible to still use the drm_simple_display_pipe helpers when
 351  * a DRM bridge has to be used.
 352  *
 353  * Note that you probably want to initialize the pipe by passing a NULL
 354  * connector to drm_simple_display_pipe_init().
 355  *
 356  * Returns:
 357  * Zero on success, negative error code on failure.
 358  */
 359 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 360                                           struct drm_bridge *bridge)
 361 {
 362         return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
 363 }
 364 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 365
 366 /**
 367  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 368  * @dev: DRM device
 369  * @pipe: simple display pipe object to initialize
 370  * @funcs: callbacks for the display pipe (optional)
 371  * @formats: array of supported formats (DRM_FORMAT\_\*)
 372  * @format_count: number of elements in @formats
 373  * @format_modifiers: array of formats modifiers
 374  * @connector: connector to attach and register (optional)
 375  *
 376  * Sets up a display pipeline which consist of a really simple
 377  * plane-crtc-encoder pipe.
 378  *
 379  * If a connector is supplied, the pipe will be coupled with the provided
 380  * connector. You may supply a NULL connector when using drm bridges, that
 381  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 382  *
 383  * Teardown of a simple display pipe is all handled automatically by the drm
 384  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 385  * release the memory for the structure themselves.
 386  *
 387  * Returns:
 388  * Zero on success, negative error code on failure.
 389  */
 390 int drm_simple_display_pipe_init(struct drm_device *dev,
 391                         struct drm_simple_display_pipe *pipe,
 392                         const struct drm_simple_display_pipe_funcs *funcs,
 393                         const uint32_t *formats, unsigned int format_count,
 394                         const uint64_t *format_modifiers,
 395                         struct drm_connector *connector)
 396 {
 397         struct drm_encoder *encoder = &pipe->encoder;
 398         struct drm_plane *plane = &pipe->plane;
 399         struct drm_crtc *crtc = &pipe->crtc;
 400         int ret;
 401
 402         pipe->connector = connector;
 403         pipe->funcs = funcs;
 404
 405         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 406         ret = drm_universal_plane_init(dev, plane, 0,
 407                                        &drm_simple_kms_plane_funcs,
 408                                        formats, format_count,
 409                                        format_modifiers,
 410                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 411         if (ret)
 412                 return ret;
 413
 414         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 415         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 416                                         &drm_simple_kms_crtc_funcs, NULL);
 417         if (ret)
 418                 return ret;
 419
 420         encoder->possible_crtcs = drm_crtc_mask(crtc);
 421         ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
 422         if (ret || !connector)
 423                 return ret;
 424
 425         return drm_connector_attach_encoder(connector, encoder);
 426 }
 427 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 428
 429 MODULE_LICENSE("GPL");