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         if (!crtc_state->enable)
 106                 goto out;
 107
 108         ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
 109         if (ret)
 110                 return ret;
 111
 112 out:
 113         return drm_atomic_add_affected_planes(state, crtc);
 114 }
 115
 116 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
 117                                        struct drm_atomic_state *state)
 118 {
 119         struct drm_plane *plane;
 120         struct drm_simple_display_pipe *pipe;
 121
 122         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 123         if (!pipe->funcs || !pipe->funcs->enable)
 124                 return;
 125
 126         plane = &pipe->plane;
 127         pipe->funcs->enable(pipe, crtc->state, plane->state);
 128 }
 129
 130 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
 131                                         struct drm_atomic_state *state)
 132 {
 133         struct drm_simple_display_pipe *pipe;
 134
 135         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 136         if (!pipe->funcs || !pipe->funcs->disable)
 137                 return;
 138
 139         pipe->funcs->disable(pipe);
 140 }
 141
 142 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 143         .mode_valid = drm_simple_kms_crtc_mode_valid,
 144         .atomic_check = drm_simple_kms_crtc_check,
 145         .atomic_enable = drm_simple_kms_crtc_enable,
 146         .atomic_disable = drm_simple_kms_crtc_disable,
 147 };
 148
 149 static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
 150 {
 151         struct drm_simple_display_pipe *pipe;
 152
 153         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 154         if (!pipe->funcs || !pipe->funcs->reset_crtc)
 155                 return drm_atomic_helper_crtc_reset(crtc);
 156
 157         return pipe->funcs->reset_crtc(pipe);
 158 }
 159
 160 static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
 161 {
 162         struct drm_simple_display_pipe *pipe;
 163
 164         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 165         if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
 166                 return drm_atomic_helper_crtc_duplicate_state(crtc);
 167
 168         return pipe->funcs->duplicate_crtc_state(pipe);
 169 }
 170
 171 static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
 172 {
 173         struct drm_simple_display_pipe *pipe;
 174
 175         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 176         if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
 177                 drm_atomic_helper_crtc_destroy_state(crtc, state);
 178         else
 179                 pipe->funcs->destroy_crtc_state(pipe, state);
 180 }
 181
 182 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 183 {
 184         struct drm_simple_display_pipe *pipe;
 185
 186         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 187         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 188                 return 0;
 189
 190         return pipe->funcs->enable_vblank(pipe);
 191 }
 192
 193 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 194 {
 195         struct drm_simple_display_pipe *pipe;
 196
 197         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 198         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 199                 return;
 200
 201         pipe->funcs->disable_vblank(pipe);
 202 }
 203
 204 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 205         .reset = drm_simple_kms_crtc_reset,
 206         .destroy = drm_crtc_cleanup,
 207         .set_config = drm_atomic_helper_set_config,
 208         .page_flip = drm_atomic_helper_page_flip,
 209         .atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
 210         .atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
 211         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 212         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 213 };
 214
 215 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 216                                         struct drm_atomic_state *state)
 217 {
 218         struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
 219                                                                              plane);
 220         struct drm_simple_display_pipe *pipe;
 221         struct drm_crtc_state *crtc_state;
 222         int ret;
 223
 224         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 225         crtc_state = drm_atomic_get_new_crtc_state(state,
 226                                                    &pipe->crtc);
 227
 228         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 229                                                   DRM_PLANE_NO_SCALING,
 230                                                   DRM_PLANE_NO_SCALING,
 231                                                   false, false);
 232         if (ret)
 233                 return ret;
 234
 235         if (!plane_state->visible)
 236                 return 0;
 237
 238         if (!pipe->funcs || !pipe->funcs->check)
 239                 return 0;
 240
 241         return pipe->funcs->check(pipe, plane_state, crtc_state);
 242 }
 243
 244 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 245                                         struct drm_atomic_state *state)
 246 {
 247         struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
 248                                                                             plane);
 249         struct drm_simple_display_pipe *pipe;
 250
 251         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 252         if (!pipe->funcs || !pipe->funcs->update)
 253                 return;
 254
 255         pipe->funcs->update(pipe, old_pstate);
 256 }
 257
 258 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 259                                            struct drm_plane_state *state)
 260 {
 261         struct drm_simple_display_pipe *pipe;
 262
 263         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 264         if (!pipe->funcs || !pipe->funcs->prepare_fb) {
 265                 if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
 266                         return 0;
 267
 268                 WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
 269
 270                 return drm_gem_plane_helper_prepare_fb(plane, state);
 271         }
 272
 273         return pipe->funcs->prepare_fb(pipe, state);
 274 }
 275
 276 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 277                                             struct drm_plane_state *state)
 278 {
 279         struct drm_simple_display_pipe *pipe;
 280
 281         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 282         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 283                 return;
 284
 285         pipe->funcs->cleanup_fb(pipe, state);
 286 }
 287
 288 static int drm_simple_kms_plane_begin_fb_access(struct drm_plane *plane,
 289                                                 struct drm_plane_state *new_plane_state)
 290 {
 291         struct drm_simple_display_pipe *pipe;
 292
 293         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 294         if (!pipe->funcs || !pipe->funcs->begin_fb_access)
 295                 return 0;
 296
 297         return pipe->funcs->begin_fb_access(pipe, new_plane_state);
 298 }
 299
 300 static void drm_simple_kms_plane_end_fb_access(struct drm_plane *plane,
 301                                                struct drm_plane_state *new_plane_state)
 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->end_fb_access)
 307                 return;
 308
 309         pipe->funcs->end_fb_access(pipe, new_plane_state);
 310 }
 311
 312 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 313                                                 uint32_t format,
 314                                                 uint64_t modifier)
 315 {
 316         return modifier == DRM_FORMAT_MOD_LINEAR;
 317 }
 318
 319 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 320         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 321         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 322         .begin_fb_access = drm_simple_kms_plane_begin_fb_access,
 323         .end_fb_access = drm_simple_kms_plane_end_fb_access,
 324         .atomic_check = drm_simple_kms_plane_atomic_check,
 325         .atomic_update = drm_simple_kms_plane_atomic_update,
 326 };
 327
 328 static void drm_simple_kms_plane_reset(struct drm_plane *plane)
 329 {
 330         struct drm_simple_display_pipe *pipe;
 331
 332         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 333         if (!pipe->funcs || !pipe->funcs->reset_plane)
 334                 return drm_atomic_helper_plane_reset(plane);
 335
 336         return pipe->funcs->reset_plane(pipe);
 337 }
 338
 339 static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
 340 {
 341         struct drm_simple_display_pipe *pipe;
 342
 343         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 344         if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
 345                 return drm_atomic_helper_plane_duplicate_state(plane);
 346
 347         return pipe->funcs->duplicate_plane_state(pipe);
 348 }
 349
 350 static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
 351                                                struct drm_plane_state *state)
 352 {
 353         struct drm_simple_display_pipe *pipe;
 354
 355         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 356         if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
 357                 drm_atomic_helper_plane_destroy_state(plane, state);
 358         else
 359                 pipe->funcs->destroy_plane_state(pipe, state);
 360 }
 361
 362 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 363         .update_plane           = drm_atomic_helper_update_plane,
 364         .disable_plane          = drm_atomic_helper_disable_plane,
 365         .destroy                = drm_plane_cleanup,
 366         .reset                  = drm_simple_kms_plane_reset,
 367         .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
 368         .atomic_destroy_state   = drm_simple_kms_plane_destroy_state,
 369         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 370 };
 371
 372 /**
 373  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 374  * @pipe: simple display pipe object
 375  * @bridge: bridge to attach
 376  *
 377  * Makes it possible to still use the drm_simple_display_pipe helpers when
 378  * a DRM bridge has to be used.
 379  *
 380  * Note that you probably want to initialize the pipe by passing a NULL
 381  * connector to drm_simple_display_pipe_init().
 382  *
 383  * Returns:
 384  * Zero on success, negative error code on failure.
 385  */
 386 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 387                                           struct drm_bridge *bridge)
 388 {
 389         return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
 390 }
 391 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 392
 393 /**
 394  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 395  * @dev: DRM device
 396  * @pipe: simple display pipe object to initialize
 397  * @funcs: callbacks for the display pipe (optional)
 398  * @formats: array of supported formats (DRM_FORMAT\_\*)
 399  * @format_count: number of elements in @formats
 400  * @format_modifiers: array of formats modifiers
 401  * @connector: connector to attach and register (optional)
 402  *
 403  * Sets up a display pipeline which consist of a really simple
 404  * plane-crtc-encoder pipe.
 405  *
 406  * If a connector is supplied, the pipe will be coupled with the provided
 407  * connector. You may supply a NULL connector when using drm bridges, that
 408  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 409  *
 410  * Teardown of a simple display pipe is all handled automatically by the drm
 411  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 412  * release the memory for the structure themselves.
 413  *
 414  * Returns:
 415  * Zero on success, negative error code on failure.
 416  */
 417 int drm_simple_display_pipe_init(struct drm_device *dev,
 418                         struct drm_simple_display_pipe *pipe,
 419                         const struct drm_simple_display_pipe_funcs *funcs,
 420                         const uint32_t *formats, unsigned int format_count,
 421                         const uint64_t *format_modifiers,
 422                         struct drm_connector *connector)
 423 {
 424         struct drm_encoder *encoder = &pipe->encoder;
 425         struct drm_plane *plane = &pipe->plane;
 426         struct drm_crtc *crtc = &pipe->crtc;
 427         int ret;
 428
 429         pipe->connector = connector;
 430         pipe->funcs = funcs;
 431
 432         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 433         ret = drm_universal_plane_init(dev, plane, 0,
 434                                        &drm_simple_kms_plane_funcs,
 435                                        formats, format_count,
 436                                        format_modifiers,
 437                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 438         if (ret)
 439                 return ret;
 440
 441         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 442         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 443                                         &drm_simple_kms_crtc_funcs, NULL);
 444         if (ret)
 445                 return ret;
 446
 447         encoder->possible_crtcs = drm_crtc_mask(crtc);
 448         ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
 449         if (ret || !connector)
 450                 return ret;
 451
 452         return drm_connector_attach_encoder(connector, encoder);
 453 }
 454 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 455
 456 MODULE_DESCRIPTION("Helpers for drivers for simple display hardware");
 457 MODULE_LICENSE("GPL");