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_crtc_helper.h>
  14 #include <drm/drm_plane_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                            BIT(drm_plane_index(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_simple_display_pipe *pipe;
  68
  69         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  70         if (!pipe->funcs || !pipe->funcs->enable)
  71                 return;
  72
  73         pipe->funcs->enable(pipe, crtc->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 const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 192         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 193         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 194         .atomic_check = drm_simple_kms_plane_atomic_check,
 195         .atomic_update = drm_simple_kms_plane_atomic_update,
 196 };
 197
 198 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 199         .update_plane           = drm_atomic_helper_update_plane,
 200         .disable_plane          = drm_atomic_helper_disable_plane,
 201         .destroy                = drm_plane_cleanup,
 202         .reset                  = drm_atomic_helper_plane_reset,
 203         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 204         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 205 };
 206
 207 /**
 208  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 209  * @pipe: simple display pipe object
 210  * @bridge: bridge to attach
 211  *
 212  * Makes it possible to still use the drm_simple_display_pipe helpers when
 213  * a DRM bridge has to be used.
 214  *
 215  * Note that you probably want to initialize the pipe by passing a NULL
 216  * connector to drm_simple_display_pipe_init().
 217  *
 218  * Returns:
 219  * Zero on success, negative error code on failure.
 220  */
 221 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 222                                           struct drm_bridge *bridge)
 223 {
 224         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 225 }
 226 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 227
 228 /**
 229  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 230  * @dev: DRM device
 231  * @pipe: simple display pipe object to initialize
 232  * @funcs: callbacks for the display pipe (optional)
 233  * @formats: array of supported formats (DRM_FORMAT\_\*)
 234  * @format_count: number of elements in @formats
 235  * @format_modifiers: array of formats modifiers
 236  * @connector: connector to attach and register (optional)
 237  *
 238  * Sets up a display pipeline which consist of a really simple
 239  * plane-crtc-encoder pipe.
 240  *
 241  * If a connector is supplied, the pipe will be coupled with the provided
 242  * connector. You may supply a NULL connector when using drm bridges, that
 243  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 244  *
 245  * Teardown of a simple display pipe is all handled automatically by the drm
 246  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 247  * release the memory for the structure themselves.
 248  *
 249  * Returns:
 250  * Zero on success, negative error code on failure.
 251  */
 252 int drm_simple_display_pipe_init(struct drm_device *dev,
 253                         struct drm_simple_display_pipe *pipe,
 254                         const struct drm_simple_display_pipe_funcs *funcs,
 255                         const uint32_t *formats, unsigned int format_count,
 256                         const uint64_t *format_modifiers,
 257                         struct drm_connector *connector)
 258 {
 259         struct drm_encoder *encoder = &pipe->encoder;
 260         struct drm_plane *plane = &pipe->plane;
 261         struct drm_crtc *crtc = &pipe->crtc;
 262         int ret;
 263
 264         pipe->connector = connector;
 265         pipe->funcs = funcs;
 266
 267         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 268         ret = drm_universal_plane_init(dev, plane, 0,
 269                                        &drm_simple_kms_plane_funcs,
 270                                        formats, format_count,
 271                                        format_modifiers,
 272                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 273         if (ret)
 274                 return ret;
 275
 276         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 277         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 278                                         &drm_simple_kms_crtc_funcs, NULL);
 279         if (ret)
 280                 return ret;
 281
 282         encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
 283         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 284                                DRM_MODE_ENCODER_NONE, NULL);
 285         if (ret || !connector)
 286                 return ret;
 287
 288         return drm_mode_connector_attach_encoder(connector, encoder);
 289 }
 290 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 291
 292 MODULE_LICENSE("GPL");