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