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 <drm/drmP.h>
   7 #include <drm/drm_atomic.h>
   8 #include <drm/drm_atomic_helper.h>
   9 #include <drm/drm_plane_helper.h>
  10 #include <drm/drm_probe_helper.h>
  11 #include <drm/drm_simple_kms_helper.h>
  12 #include <linux/slab.h>
  13
  14 /**
  15  * DOC: overview
  16  *
  17  * This helper library provides helpers for drivers for simple display
  18  * hardware.
  19  *
  20  * drm_simple_display_pipe_init() initializes a simple display pipeline
  21  * which has only one full-screen scanout buffer feeding one output. The
  22  * pipeline is represented by &struct drm_simple_display_pipe and binds
  23  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  24  * entity. Some flexibility for code reuse is provided through a separately
  25  * allocated &drm_connector object and supporting optional &drm_bridge
  26  * encoder drivers.
  27  */
  28
  29 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
  30         .destroy = drm_encoder_cleanup,
  31 };
  32
  33 static enum drm_mode_status
  34 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  35                                const struct drm_display_mode *mode)
  36 {
  37         struct drm_simple_display_pipe *pipe;
  38
  39         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  40         if (!pipe->funcs || !pipe->funcs->mode_valid)
  41                 /* Anything goes */
  42                 return MODE_OK;
  43
  44         return pipe->funcs->mode_valid(crtc, mode);
  45 }
  46
  47 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  48                                      struct drm_crtc_state *state)
  49 {
  50         bool has_primary = state->plane_mask &
  51                            drm_plane_mask(crtc->primary);
  52
  53         /* We always want to have an active plane with an active CRTC */
  54         if (has_primary != state->enable)
  55                 return -EINVAL;
  56
  57         return drm_atomic_add_affected_planes(state->state, crtc);
  58 }
  59
  60 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
  61                                        struct drm_crtc_state *old_state)
  62 {
  63         struct drm_plane *plane;
  64         struct drm_simple_display_pipe *pipe;
  65
  66         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  67         if (!pipe->funcs || !pipe->funcs->enable)
  68                 return;
  69
  70         plane = &pipe->plane;
  71         pipe->funcs->enable(pipe, crtc->state, plane->state);
  72 }
  73
  74 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
  75                                         struct drm_crtc_state *old_state)
  76 {
  77         struct drm_simple_display_pipe *pipe;
  78
  79         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  80         if (!pipe->funcs || !pipe->funcs->disable)
  81                 return;
  82
  83         pipe->funcs->disable(pipe);
  84 }
  85
  86 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  87         .mode_valid = drm_simple_kms_crtc_mode_valid,
  88         .atomic_check = drm_simple_kms_crtc_check,
  89         .atomic_enable = drm_simple_kms_crtc_enable,
  90         .atomic_disable = drm_simple_kms_crtc_disable,
  91 };
  92
  93 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
  94 {
  95         struct drm_simple_display_pipe *pipe;
  96
  97         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  98         if (!pipe->funcs || !pipe->funcs->enable_vblank)
  99                 return 0;
 100
 101         return pipe->funcs->enable_vblank(pipe);
 102 }
 103
 104 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 105 {
 106         struct drm_simple_display_pipe *pipe;
 107
 108         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 109         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 110                 return;
 111
 112         pipe->funcs->disable_vblank(pipe);
 113 }
 114
 115 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 116         .reset = drm_atomic_helper_crtc_reset,
 117         .destroy = drm_crtc_cleanup,
 118         .set_config = drm_atomic_helper_set_config,
 119         .page_flip = drm_atomic_helper_page_flip,
 120         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 121         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 122         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 123         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 124 };
 125
 126 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 127                                         struct drm_plane_state *plane_state)
 128 {
 129         struct drm_simple_display_pipe *pipe;
 130         struct drm_crtc_state *crtc_state;
 131         int ret;
 132
 133         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 134         crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
 135                                                    &pipe->crtc);
 136
 137         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 138                                                   DRM_PLANE_HELPER_NO_SCALING,
 139                                                   DRM_PLANE_HELPER_NO_SCALING,
 140                                                   false, true);
 141         if (ret)
 142                 return ret;
 143
 144         if (!plane_state->visible)
 145                 return 0;
 146
 147         if (!pipe->funcs || !pipe->funcs->check)
 148                 return 0;
 149
 150         return pipe->funcs->check(pipe, plane_state, crtc_state);
 151 }
 152
 153 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 154                                         struct drm_plane_state *old_pstate)
 155 {
 156         struct drm_simple_display_pipe *pipe;
 157
 158         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 159         if (!pipe->funcs || !pipe->funcs->update)
 160                 return;
 161
 162         pipe->funcs->update(pipe, old_pstate);
 163 }
 164
 165 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 166                                            struct drm_plane_state *state)
 167 {
 168         struct drm_simple_display_pipe *pipe;
 169
 170         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 171         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 172                 return 0;
 173
 174         return pipe->funcs->prepare_fb(pipe, state);
 175 }
 176
 177 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 178                                             struct drm_plane_state *state)
 179 {
 180         struct drm_simple_display_pipe *pipe;
 181
 182         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 183         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 184                 return;
 185
 186         pipe->funcs->cleanup_fb(pipe, state);
 187 }
 188
 189 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 190                                                 uint32_t format,
 191                                                 uint64_t modifier)
 192 {
 193         return modifier == DRM_FORMAT_MOD_LINEAR;
 194 }
 195
 196 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 197         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 198         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 199         .atomic_check = drm_simple_kms_plane_atomic_check,
 200         .atomic_update = drm_simple_kms_plane_atomic_update,
 201 };
 202
 203 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 204         .update_plane           = drm_atomic_helper_update_plane,
 205         .disable_plane          = drm_atomic_helper_disable_plane,
 206         .destroy                = drm_plane_cleanup,
 207         .reset                  = drm_atomic_helper_plane_reset,
 208         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 209         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 210         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 211 };
 212
 213 /**
 214  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 215  * @pipe: simple display pipe object
 216  * @bridge: bridge to attach
 217  *
 218  * Makes it possible to still use the drm_simple_display_pipe helpers when
 219  * a DRM bridge has to be used.
 220  *
 221  * Note that you probably want to initialize the pipe by passing a NULL
 222  * connector to drm_simple_display_pipe_init().
 223  *
 224  * Returns:
 225  * Zero on success, negative error code on failure.
 226  */
 227 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 228                                           struct drm_bridge *bridge)
 229 {
 230         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 231 }
 232 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 233
 234 /**
 235  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 236  * @dev: DRM device
 237  * @pipe: simple display pipe object to initialize
 238  * @funcs: callbacks for the display pipe (optional)
 239  * @formats: array of supported formats (DRM_FORMAT\_\*)
 240  * @format_count: number of elements in @formats
 241  * @format_modifiers: array of formats modifiers
 242  * @connector: connector to attach and register (optional)
 243  *
 244  * Sets up a display pipeline which consist of a really simple
 245  * plane-crtc-encoder pipe.
 246  *
 247  * If a connector is supplied, the pipe will be coupled with the provided
 248  * connector. You may supply a NULL connector when using drm bridges, that
 249  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 250  *
 251  * Teardown of a simple display pipe is all handled automatically by the drm
 252  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 253  * release the memory for the structure themselves.
 254  *
 255  * Returns:
 256  * Zero on success, negative error code on failure.
 257  */
 258 int drm_simple_display_pipe_init(struct drm_device *dev,
 259                         struct drm_simple_display_pipe *pipe,
 260                         const struct drm_simple_display_pipe_funcs *funcs,
 261                         const uint32_t *formats, unsigned int format_count,
 262                         const uint64_t *format_modifiers,
 263                         struct drm_connector *connector)
 264 {
 265         struct drm_encoder *encoder = &pipe->encoder;
 266         struct drm_plane *plane = &pipe->plane;
 267         struct drm_crtc *crtc = &pipe->crtc;
 268         int ret;
 269
 270         pipe->connector = connector;
 271         pipe->funcs = funcs;
 272
 273         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 274         ret = drm_universal_plane_init(dev, plane, 0,
 275                                        &drm_simple_kms_plane_funcs,
 276                                        formats, format_count,
 277                                        format_modifiers,
 278                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 279         if (ret)
 280                 return ret;
 281
 282         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 283         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 284                                         &drm_simple_kms_crtc_funcs, NULL);
 285         if (ret)
 286                 return ret;
 287
 288         encoder->possible_crtcs = drm_crtc_mask(crtc);
 289         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 290                                DRM_MODE_ENCODER_NONE, NULL);
 291         if (ret || !connector)
 292                 return ret;
 293
 294         return drm_connector_attach_encoder(connector, encoder);
 295 }
 296 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 297
 298 MODULE_LICENSE("GPL");