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 int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
  38                                      struct drm_crtc_state *state)
  39 {
  40         bool has_primary = state->plane_mask &
  41                            BIT(drm_plane_index(crtc->primary));
  42
  43         /* We always want to have an active plane with an active CRTC */
  44         if (has_primary != state->enable)
  45                 return -EINVAL;
  46
  47         return drm_atomic_add_affected_planes(state->state, crtc);
  48 }
  49
  50 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
  51                                        struct drm_crtc_state *old_state)
  52 {
  53         struct drm_simple_display_pipe *pipe;
  54
  55         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  56         if (!pipe->funcs || !pipe->funcs->enable)
  57                 return;
  58
  59         pipe->funcs->enable(pipe, crtc->state);
  60 }
  61
  62 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
  63                                         struct drm_crtc_state *old_state)
  64 {
  65         struct drm_simple_display_pipe *pipe;
  66
  67         pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
  68         if (!pipe->funcs || !pipe->funcs->disable)
  69                 return;
  70
  71         pipe->funcs->disable(pipe);
  72 }
  73
  74 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
  75         .atomic_check = drm_simple_kms_crtc_check,
  76         .atomic_enable = drm_simple_kms_crtc_enable,
  77         .atomic_disable = drm_simple_kms_crtc_disable,
  78 };
  79
  80 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
  81         .reset = drm_atomic_helper_crtc_reset,
  82         .destroy = drm_crtc_cleanup,
  83         .set_config = drm_atomic_helper_set_config,
  84         .page_flip = drm_atomic_helper_page_flip,
  85         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
  86         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
  87 };
  88
  89 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
  90                                         struct drm_plane_state *plane_state)
  91 {
  92         struct drm_rect clip = { 0 };
  93         struct drm_simple_display_pipe *pipe;
  94         struct drm_crtc_state *crtc_state;
  95         int ret;
  96
  97         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
  98         crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
  99                                                    &pipe->crtc);
 100         if (!crtc_state->enable)
 101                 return 0; /* nothing to check when disabling or disabled */
 102
 103         clip.x2 = crtc_state->adjusted_mode.hdisplay;
 104         clip.y2 = crtc_state->adjusted_mode.vdisplay;
 105
 106         ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
 107                                                   &clip,
 108                                                   DRM_PLANE_HELPER_NO_SCALING,
 109                                                   DRM_PLANE_HELPER_NO_SCALING,
 110                                                   false, true);
 111         if (ret)
 112                 return ret;
 113
 114         if (!plane_state->visible)
 115                 return -EINVAL;
 116
 117         if (!pipe->funcs || !pipe->funcs->check)
 118                 return 0;
 119
 120         return pipe->funcs->check(pipe, plane_state, crtc_state);
 121 }
 122
 123 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
 124                                         struct drm_plane_state *old_pstate)
 125 {
 126         struct drm_simple_display_pipe *pipe;
 127
 128         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 129         if (!pipe->funcs || !pipe->funcs->update)
 130                 return;
 131
 132         pipe->funcs->update(pipe, old_pstate);
 133 }
 134
 135 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
 136                                            struct drm_plane_state *state)
 137 {
 138         struct drm_simple_display_pipe *pipe;
 139
 140         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 141         if (!pipe->funcs || !pipe->funcs->prepare_fb)
 142                 return 0;
 143
 144         return pipe->funcs->prepare_fb(pipe, state);
 145 }
 146
 147 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
 148                                             struct drm_plane_state *state)
 149 {
 150         struct drm_simple_display_pipe *pipe;
 151
 152         pipe = container_of(plane, struct drm_simple_display_pipe, plane);
 153         if (!pipe->funcs || !pipe->funcs->cleanup_fb)
 154                 return;
 155
 156         pipe->funcs->cleanup_fb(pipe, state);
 157 }
 158
 159 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
 160         .prepare_fb = drm_simple_kms_plane_prepare_fb,
 161         .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
 162         .atomic_check = drm_simple_kms_plane_atomic_check,
 163         .atomic_update = drm_simple_kms_plane_atomic_update,
 164 };
 165
 166 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
 167         .update_plane           = drm_atomic_helper_update_plane,
 168         .disable_plane          = drm_atomic_helper_disable_plane,
 169         .destroy                = drm_plane_cleanup,
 170         .reset                  = drm_atomic_helper_plane_reset,
 171         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 172         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 173 };
 174
 175 /**
 176  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
 177  * @pipe: simple display pipe object
 178  * @bridge: bridge to attach
 179  *
 180  * Makes it possible to still use the drm_simple_display_pipe helpers when
 181  * a DRM bridge has to be used.
 182  *
 183  * Note that you probably want to initialize the pipe by passing a NULL
 184  * connector to drm_simple_display_pipe_init().
 185  *
 186  * Returns:
 187  * Zero on success, negative error code on failure.
 188  */
 189 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
 190                                           struct drm_bridge *bridge)
 191 {
 192         return drm_bridge_attach(&pipe->encoder, bridge, NULL);
 193 }
 194 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
 195
 196 /**
 197  * drm_simple_display_pipe_init - Initialize a simple display pipeline
 198  * @dev: DRM device
 199  * @pipe: simple display pipe object to initialize
 200  * @funcs: callbacks for the display pipe (optional)
 201  * @formats: array of supported formats (DRM_FORMAT\_\*)
 202  * @format_count: number of elements in @formats
 203  * @format_modifiers: array of formats modifiers
 204  * @connector: connector to attach and register (optional)
 205  *
 206  * Sets up a display pipeline which consist of a really simple
 207  * plane-crtc-encoder pipe.
 208  *
 209  * If a connector is supplied, the pipe will be coupled with the provided
 210  * connector. You may supply a NULL connector when using drm bridges, that
 211  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
 212  *
 213  * Teardown of a simple display pipe is all handled automatically by the drm
 214  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
 215  * release the memory for the structure themselves.
 216  *
 217  * Returns:
 218  * Zero on success, negative error code on failure.
 219  */
 220 int drm_simple_display_pipe_init(struct drm_device *dev,
 221                         struct drm_simple_display_pipe *pipe,
 222                         const struct drm_simple_display_pipe_funcs *funcs,
 223                         const uint32_t *formats, unsigned int format_count,
 224                         const uint64_t *format_modifiers,
 225                         struct drm_connector *connector)
 226 {
 227         struct drm_encoder *encoder = &pipe->encoder;
 228         struct drm_plane *plane = &pipe->plane;
 229         struct drm_crtc *crtc = &pipe->crtc;
 230         int ret;
 231
 232         pipe->connector = connector;
 233         pipe->funcs = funcs;
 234
 235         drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
 236         ret = drm_universal_plane_init(dev, plane, 0,
 237                                        &drm_simple_kms_plane_funcs,
 238                                        formats, format_count,
 239                                        format_modifiers,
 240                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 241         if (ret)
 242                 return ret;
 243
 244         drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
 245         ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
 246                                         &drm_simple_kms_crtc_funcs, NULL);
 247         if (ret)
 248                 return ret;
 249
 250         encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
 251         ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
 252                                DRM_MODE_ENCODER_NONE, NULL);
 253         if (ret || !connector)
 254                 return ret;
 255
 256         return drm_mode_connector_attach_encoder(connector, encoder);
 257 }
 258 EXPORT_SYMBOL(drm_simple_display_pipe_init);
 259
 260 MODULE_LICENSE("GPL");