drivers/gpu/drm/drm_simple_kms_helper.c

   1 /*
   2  * Copyright (C) 2016 Noralf Trønnes
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  */
   9
  10 #include <drm/drmP.h>
  11 #include <drm/drm_atomic.h>
  12 #include <drm/drm_atomic_helper.h>
  13 #include <drm/drm_plane_helper.h>
  14 #include <drm/drm_probe_helper.h>
  15 #include <drm/drm_simple_kms_helper.h>
  16 #include <linux/slab.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
  33 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
  34         .destroy = drm_encoder_cleanup,
  35 };
  36
  37 static enum drm_mode_status
  38 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
  39                                const struct drm_display_mode *mode)
  40 {
  41         struct drm_simple_display_pipe *pipe;
  42
  43         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  44         if (!pipe->funcs || !pipe->funcs->mode_valid)
  45                 /* Anything goes */
  46                 return MODE_OK;
  47
  48         return pipe->funcs->mode_valid(crtc, mode);
  49 }
  50
  51 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  52                                      struct drm_crtc_state *state)
  53 {
  54         bool has_primary = state->plane_mask &
  55                            drm_plane_mask(crtc->primary);
  56
  57         /* We always want to have an active plane with an active CRTC */
  58         if (has_primary != state->enable)
  59                 return -EINVAL;
  60
  61         return drm_atomic_add_affected_planes(state->state, crtc);
  62 }
  63
  64 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
  65                                        struct drm_crtc_state *old_state)
  66 {
  67         struct drm_plane *plane;
  68         struct drm_simple_display_pipe *pipe;
  69
  70         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  71         if (!pipe->funcs || !pipe->funcs->enable)
  72                 return;
  73
  74         plane = &pipe->plane;
  75         pipe->funcs->enable(pipe, crtc->state, plane->state);
  76 }
  77
  78 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
  79                                         struct drm_crtc_state *old_state)
  80 {
  81         struct drm_simple_display_pipe *pipe;
  82
  83         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  84         if (!pipe->funcs || !pipe->funcs->disable)
  85                 return;
  86
  87         pipe->funcs->disable(pipe);
  88 }
  89
  90 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  91         .mode_valid = drm_simple_kms_crtc_mode_valid,
  92         .atomic_check = drm_simple_kms_crtc_check,
  93         .atomic_enable = drm_simple_kms_crtc_enable,
  94         .atomic_disable = drm_simple_kms_crtc_disable,
  95 };
  96
  97 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
  98 {
  99         struct drm_simple_display_pipe *pipe;
 100
 101         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 102         if (!pipe->funcs || !pipe->funcs->enable_vblank)
 103                 return 0;
 104
 105         return pipe->funcs->enable_vblank(pipe);
 106 }
 107
 108 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 109 {
 110         struct drm_simple_display_pipe *pipe;
 111
 112         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
 113         if (!pipe->funcs || !pipe->funcs->disable_vblank)
 114                 return;
 115
 116         pipe->funcs->disable_vblank(pipe);
 117 }
 118
 119 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
 120         .reset = drm_atomic_helper_crtc_reset,
 121         .destroy = drm_crtc_cleanup,
 122         .set_config = drm_atomic_helper_set_config,
 123         .page_flip = drm_atomic_helper_page_flip,
 124         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 125         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 126         .enable_vblank = drm_simple_kms_crtc_enable_vblank,
 127         .disable_vblank = drm_simple_kms_crtc_disable_vblank,
 128 };
 129
 130 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 131                                         struct drm_plane_state *plane_state)
 132 {
 133         struct drm_simple_display_pipe *pipe;
 134         struct drm_crtc_state *crtc_state;
 135         int ret;
 136
 137         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 138         crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
 139                                                    &pipe->crtc);
 140
 141         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 142                                                   DRM_PLANE_HELPER_NO_SCALING,
 143                                                   DRM_PLANE_HELPER_NO_SCALING,
 144                                                   false, true);
 145         if (ret)
 146                 return ret;
 147
 148         if (!plane_state->visible)
 149                 return 0;
 150
 151         if (!pipe->funcs || !pipe->funcs->check)
 152                 return 0;
 153
 154         return pipe->funcs->check(pipe, plane_state, crtc_state);
 155 }
 156
 157 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 158                                         struct drm_plane_state *old_pstate)
 159 {
 160         struct drm_simple_display_pipe *pipe;
 161
 162         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 163         if (!pipe->funcs || !pipe->funcs->update)
 164                 return;
 165
 166         pipe->funcs->update(pipe, old_pstate);
 167 }
 168
 169 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 170                                            struct drm_plane_state *state)
 171 {
 172         struct drm_simple_display_pipe *pipe;
 173
 174         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 175         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 176                 return 0;
 177
 178         return pipe->funcs->prepare_fb(pipe, state);
 179 }
 180
 181 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 182                                             struct drm_plane_state *state)
 183 {
 184         struct drm_simple_display_pipe *pipe;
 185
 186         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 187         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 188                 return;
 189
 190         pipe->funcs->cleanup_fb(pipe, state);
 191 }
 192
 193 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
 194                                                 uint32_t format,
 195                                                 uint64_t modifier)
 196 {
 197         return modifier == DRM_FORMAT_MOD_LINEAR;
 198 }
 199
 200 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 201         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 202         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 203         .atomic_check = drm_simple_kms_plane_atomic_check,
 204         .atomic_update = drm_simple_kms_plane_atomic_update,
 205 };
 206
 207 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 208         .update_plane           = drm_atomic_helper_update_plane,
 209         .disable_plane          = drm_atomic_helper_disable_plane,
 210         .destroy                = drm_plane_cleanup,
 211         .reset                  = drm_atomic_helper_plane_reset,
 212         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 213         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 214         .format_mod_supported   = drm_simple_kms_format_mod_supported,
 215 };
 216
 217 /**
 218  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 219  * @pipe: simple display pipe object
 220  * @bridge: bridge to attach
 221  *
 222  * Makes it possible to still use the drm_simple_display_pipe helpers when
 223  * a DRM bridge has to be used.
 224  *
 225  * Note that you probably want to initialize the pipe by passing a NULL
 226  * connector to drm_simple_display_pipe_init().
 227  *
 228  * Returns:
 229  * Zero on success, negative error code on failure.
 230  */
 231 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 232                                           struct drm_bridge *bridge)
 233 {
 234         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 235 }
 236 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 237
 238 /**
 239  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 240  * @dev: DRM device
 241  * @pipe: simple display pipe object to initialize
 242  * @funcs: callbacks for the display pipe (optional)
 243  * @formats: array of supported formats (DRM_FORMAT\_\*)
 244  * @format_count: number of elements in @formats
 245  * @format_modifiers: array of formats modifiers
 246  * @connector: connector to attach and register (optional)
 247  *
 248  * Sets up a display pipeline which consist of a really simple
 249  * plane-crtc-encoder pipe.
 250  *
 251  * If a connector is supplied, the pipe will be coupled with the provided
 252  * connector. You may supply a NULL connector when using drm bridges, that
 253  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 254  *
 255  * Teardown of a simple display pipe is all handled automatically by the drm
 256  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 257  * release the memory for the structure themselves.
 258  *
 259  * Returns:
 260  * Zero on success, negative error code on failure.
 261  */
 262 int drm_simple_display_pipe_init(struct drm_device *dev,
 263                         struct drm_simple_display_pipe *pipe,
 264                         const struct drm_simple_display_pipe_funcs *funcs,
 265                         const uint32_t *formats, unsigned int format_count,
 266                         const uint64_t *format_modifiers,
 267                         struct drm_connector *connector)
 268 {
 269         struct drm_encoder *encoder = &pipe->encoder;
 270         struct drm_plane *plane = &pipe->plane;
 271         struct drm_crtc *crtc = &pipe->crtc;
 272         int ret;
 273
 274         pipe->connector = connector;
 275         pipe->funcs = funcs;
 276
 277         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 278         ret = drm_universal_plane_init(dev, plane, 0,
 279                                        &drm_simple_kms_plane_funcs,
 280                                        formats, format_count,
 281                                        format_modifiers,
 282                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 283         if (ret)
 284                 return ret;
 285
 286         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 287         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 288                                         &drm_simple_kms_crtc_funcs, NULL);
 289         if (ret)
 290                 return ret;
 291
 292         encoder->possible_crtcs = drm_crtc_mask(crtc);
 293         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 294                                DRM_MODE_ENCODER_NONE, NULL);
 295         if (ret || !connector)
 296                 return ret;
 297
 298         return drm_connector_attach_encoder(connector, encoder);
 299 }
 300 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 301
 302 MODULE_LICENSE("GPL");