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_plane_helper.h>
  13 #include <drm/drm_probe_helper.h>
  14 #include <drm/drm_simple_kms_helper.h>
  15
  16 /**
  17  * DOC: overview
  18  *
  19  * This helper library provides helpers for drivers for simple display
  20  * hardware.
  21  *
  22  * drm_simple_display_pipe_init() initializes a simple display pipeline
  23  * which has only one full-screen scanout buffer feeding one output. The
  24  * pipeline is represented by &struct drm_simple_display_pipe and binds
  25  * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
  26  * entity. Some flexibility for code reuse is provided through a separately
  27  * allocated &drm_connector object and supporting optional &drm_bridge
  28  * encoder drivers.
  29  */
  30
  31 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
  32         .destroy = drm_encoder_cleanup,
  33 };
  34
  35 static enum drm_mode_status
  36 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  37                                const struct drm_display_mode *mode)
  38 {
  39         struct drm_simple_display_pipe *pipe;
  40
  41         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  42         if (!pipe->funcs || !pipe->funcs->mode_valid)
  43                 /* Anything goes */
  44                 return MODE_OK;
  45
  46         return pipe->funcs->mode_valid(pipe, mode);
  47 }
  48
  49 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  50                                      struct drm_crtc_state *state)
  51 {
  52         bool has_primary = state->plane_mask &
  53                            drm_plane_mask(crtc->primary);
  54
  55         /* We always want to have an active plane with an active CRTC */
  56         if (has_primary != state->enable)
  57                 return -EINVAL;
  58
  59         return drm_atomic_add_affected_planes(state->state, crtc);
  60 }
  61
  62 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
  63                                        struct drm_crtc_state *old_state)
  64 {
  65         struct drm_plane *plane;
  66         struct drm_simple_display_pipe *pipe;
  67
  68         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  69         if (!pipe->funcs || !pipe->funcs->enable)
  70                 return;
  71
  72         plane = &pipe->plane;
  73         pipe->funcs->enable(pipe, crtc->state, plane->state);
  74 }
  75
  76 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
  77                                         struct drm_crtc_state *old_state)
  78 {
  79         struct drm_simple_display_pipe *pipe;
  80
  81         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  82         if (!pipe->funcs || !pipe->funcs->disable)
  83                 return;
  84
  85         pipe->funcs->disable(pipe);
  86 }
  87
  88 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  89         .mode_valid = drm_simple_kms_crtc_mode_valid,
  90         .atomic_check = drm_simple_kms_crtc_check,
  91         .atomic_enable = drm_simple_kms_crtc_enable,
  92         .atomic_disable = drm_simple_kms_crtc_disable,
  93 };
  94
  95 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
  96 {
  97         struct drm_simple_display_pipe *pipe;
  98
  99         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 100         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 101                 return 0;
 102
 103         return pipe->funcs->enable_vblank(pipe);
 104 }
 105
 106 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 107 {
 108         struct drm_simple_display_pipe *pipe;
 109
 110         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 111         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 112                 return;
 113
 114         pipe->funcs->disable_vblank(pipe);
 115 }
 116
 117 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 118         .reset = drm_atomic_helper_crtc_reset,
 119         .destroy = drm_crtc_cleanup,
 120         .set_config = drm_atomic_helper_set_config,
 121         .page_flip = drm_atomic_helper_page_flip,
 122         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 123         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 124         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 125         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 126 };
 127
 128 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 129                                         struct drm_plane_state *plane_state)
 130 {
 131         struct drm_simple_display_pipe *pipe;
 132         struct drm_crtc_state *crtc_state;
 133         int ret;
 134
 135         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 136         crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
 137                                                    &pipe->crtc);
 138
 139         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 140                                                   DRM_PLANE_HELPER_NO_SCALING,
 141                                                   DRM_PLANE_HELPER_NO_SCALING,
 142                                                   false, true);
 143         if (ret)
 144                 return ret;
 145
 146         if (!plane_state->visible)
 147                 return 0;
 148
 149         if (!pipe->funcs || !pipe->funcs->check)
 150                 return 0;
 151
 152         return pipe->funcs->check(pipe, plane_state, crtc_state);
 153 }
 154
 155 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 156                                         struct drm_plane_state *old_pstate)
 157 {
 158         struct drm_simple_display_pipe *pipe;
 159
 160         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 161         if (!pipe->funcs || !pipe->funcs->update)
 162                 return;
 163
 164         pipe->funcs->update(pipe, old_pstate);
 165 }
 166
 167 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 168                                            struct drm_plane_state *state)
 169 {
 170         struct drm_simple_display_pipe *pipe;
 171
 172         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 173         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 174                 return 0;
 175
 176         return pipe->funcs->prepare_fb(pipe, state);
 177 }
 178
 179 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 180                                             struct drm_plane_state *state)
 181 {
 182         struct drm_simple_display_pipe *pipe;
 183
 184         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 185         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 186                 return;
 187
 188         pipe->funcs->cleanup_fb(pipe, state);
 189 }
 190
 191 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 192                                                 uint32_t format,
 193                                                 uint64_t modifier)
 194 {
 195         return modifier == DRM_FORMAT_MOD_LINEAR;
 196 }
 197
 198 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 199         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 200         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 201         .atomic_check = drm_simple_kms_plane_atomic_check,
 202         .atomic_update = drm_simple_kms_plane_atomic_update,
 203 };
 204
 205 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 206         .update_plane           = drm_atomic_helper_update_plane,
 207         .disable_plane          = drm_atomic_helper_disable_plane,
 208         .destroy                = drm_plane_cleanup,
 209         .reset                  = drm_atomic_helper_plane_reset,
 210         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 211         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 212         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 213 };
 214
 215 /**
 216  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 217  * @pipe: simple display pipe object
 218  * @bridge: bridge to attach
 219  *
 220  * Makes it possible to still use the drm_simple_display_pipe helpers when
 221  * a DRM bridge has to be used.
 222  *
 223  * Note that you probably want to initialize the pipe by passing a NULL
 224  * connector to drm_simple_display_pipe_init().
 225  *
 226  * Returns:
 227  * Zero on success, negative error code on failure.
 228  */
 229 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 230                                           struct drm_bridge *bridge)
 231 {
 232         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 233 }
 234 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 235
 236 /**
 237  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 238  * @dev: DRM device
 239  * @pipe: simple display pipe object to initialize
 240  * @funcs: callbacks for the display pipe (optional)
 241  * @formats: array of supported formats (DRM_FORMAT\_\*)
 242  * @format_count: number of elements in @formats
 243  * @format_modifiers: array of formats modifiers
 244  * @connector: connector to attach and register (optional)
 245  *
 246  * Sets up a display pipeline which consist of a really simple
 247  * plane-crtc-encoder pipe.
 248  *
 249  * If a connector is supplied, the pipe will be coupled with the provided
 250  * connector. You may supply a NULL connector when using drm bridges, that
 251  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 252  *
 253  * Teardown of a simple display pipe is all handled automatically by the drm
 254  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 255  * release the memory for the structure themselves.
 256  *
 257  * Returns:
 258  * Zero on success, negative error code on failure.
 259  */
 260 int drm_simple_display_pipe_init(struct drm_device *dev,
 261                         struct drm_simple_display_pipe *pipe,
 262                         const struct drm_simple_display_pipe_funcs *funcs,
 263                         const uint32_t *formats, unsigned int format_count,
 264                         const uint64_t *format_modifiers,
 265                         struct drm_connector *connector)
 266 {
 267         struct drm_encoder *encoder = &pipe->encoder;
 268         struct drm_plane *plane = &pipe->plane;
 269         struct drm_crtc *crtc = &pipe->crtc;
 270         int ret;
 271
 272         pipe->connector = connector;
 273         pipe->funcs = funcs;
 274
 275         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 276         ret = drm_universal_plane_init(dev, plane, 0,
 277                                        &drm_simple_kms_plane_funcs,
 278                                        formats, format_count,
 279                                        format_modifiers,
 280                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 281         if (ret)
 282                 return ret;
 283
 284         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 285         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 286                                         &drm_simple_kms_crtc_funcs, NULL);
 287         if (ret)
 288                 return ret;
 289
 290         encoder->possible_crtcs = drm_crtc_mask(crtc);
 291         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 292                                DRM_MODE_ENCODER_NONE, NULL);
 293         if (ret || !connector)
 294                 return ret;
 295
 296         return drm_connector_attach_encoder(connector, encoder);
 297 }
 298 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 299
 300 MODULE_LICENSE("GPL");