drivers/gpu/drm/drm_plane_helper.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation
   3  *
   4  * DRM universal plane helper functions
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <linux/list.h>
  27
  28 #include <drm/drm_atomic.h>
  29 #include <drm/drm_atomic_helper.h>
  30 #include <drm/drm_atomic_uapi.h>
  31 #include <drm/drm_device.h>
  32 #include <drm/drm_drv.h>
  33 #include <drm/drm_encoder.h>
  34 #include <drm/drm_plane_helper.h>
  35 #include <drm/drm_print.h>
  36 #include <drm/drm_rect.h>
  37
  38 #define SUBPIXEL_MASK 0xffff
  39
  40 /**
  41  * DOC: overview
  42  *
  43  * This helper library contains helpers to implement primary plane support on
  44  * top of the normal CRTC configuration interface.
  45  * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
  46  * plane together with the CRTC state this does not allow userspace to disable
  47  * the primary plane itself. The default primary plane only expose XRBG8888 and
  48  * ARGB8888 as valid pixel formats for the attached framebuffer.
  49  *
  50  * Drivers are highly recommended to implement proper support for primary
  51  * planes, and newly merged drivers must not rely upon these transitional
  52  * helpers.
  53  *
  54  * The plane helpers share the function table structures with other helpers,
  55  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
  56  * the details.
  57  */
  58
  59 /*
  60  * Returns the connectors currently associated with a CRTC.  This function
  61  * should be called twice:  once with a NULL connector list to retrieve
  62  * the list size, and once with the properly allocated list to be filled in.
  63  */
  64 static int get_connectors_for_crtc(struct drm_crtc *crtc,
  65                                    struct drm_connector **connector_list,
  66                                    int num_connectors)
  67 {
  68         struct drm_device *dev = crtc->dev;
  69         struct drm_connector *connector;
  70         struct drm_connector_list_iter conn_iter;
  71         int count = 0;
  72
  73         /*
  74          * Note: Once we change the plane hooks to more fine-grained locking we
  75          * need to grab the connection_mutex here to be able to make these
  76          * checks.
  77          */
  78         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
  79
  80         drm_connector_list_iter_begin(dev, &conn_iter);
  81         drm_for_each_connector_iter(connector, &conn_iter) {
  82                 if (connector->encoder && connector->encoder->crtc == crtc) {
  83                         if (connector_list != NULL && count < num_connectors)
  84                                 *(connector_list++) = connector;
  85
  86                         count++;
  87                 }
  88         }
  89         drm_connector_list_iter_end(&conn_iter);
  90
  91         return count;
  92 }
  93
  94 static int drm_plane_helper_check_update(struct drm_plane *plane,
  95                                          struct drm_crtc *crtc,
  96                                          struct drm_framebuffer *fb,
  97                                          struct drm_rect *src,
  98                                          struct drm_rect *dst,
  99                                          unsigned int rotation,
 100                                          int min_scale,
 101                                          int max_scale,
 102                                          bool can_position,
 103                                          bool can_update_disabled,
 104                                          bool *visible)
 105 {
 106         struct drm_plane_state plane_state = {
 107                 .plane = plane,
 108                 .crtc = crtc,
 109                 .fb = fb,
 110                 .src_x = src->x1,
 111                 .src_y = src->y1,
 112                 .src_w = drm_rect_width(src),
 113                 .src_h = drm_rect_height(src),
 114                 .crtc_x = dst->x1,
 115                 .crtc_y = dst->y1,
 116                 .crtc_w = drm_rect_width(dst),
 117                 .crtc_h = drm_rect_height(dst),
 118                 .rotation = rotation,
 119         };
 120         struct drm_crtc_state crtc_state = {
 121                 .crtc = crtc,
 122                 .enable = crtc->enabled,
 123                 .mode = crtc->mode,
 124         };
 125         int ret;
 126
 127         ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
 128                                                   min_scale, max_scale,
 129                                                   can_position,
 130                                                   can_update_disabled);
 131         if (ret)
 132                 return ret;
 133
 134         *src = plane_state.src;
 135         *dst = plane_state.dst;
 136         *visible = plane_state.visible;
 137
 138         return 0;
 139 }
 140
 141 /**
 142  * drm_plane_helper_update_primary - Helper for updating primary planes
 143  * @plane: plane to update
 144  * @crtc: the plane's new CRTC
 145  * @fb: the plane's new framebuffer
 146  * @crtc_x: x coordinate within CRTC
 147  * @crtc_y: y coordinate within CRTC
 148  * @crtc_w: width coordinate within CRTC
 149  * @crtc_h: height coordinate within CRTC
 150  * @src_x: x coordinate within source
 151  * @src_y: y coordinate within source
 152  * @src_w: width coordinate within source
 153  * @src_h: height coordinate within source
 154  * @ctx: modeset locking context
 155  *
 156  * This helper validates the given parameters and updates the primary plane.
 157  *
 158  * This function is only useful for non-atomic modesetting. Don't use
 159  * it in new drivers.
 160  *
 161  * Returns:
 162  * Zero on success, or an errno code otherwise.
 163  */
 164 int drm_plane_helper_update_primary(struct drm_plane *plane, struct drm_crtc *crtc,
 165                                     struct drm_framebuffer *fb,
 166                                     int crtc_x, int crtc_y,
 167                                     unsigned int crtc_w, unsigned int crtc_h,
 168                                     uint32_t src_x, uint32_t src_y,
 169                                     uint32_t src_w, uint32_t src_h,
 170                                     struct drm_modeset_acquire_ctx *ctx)
 171 {
 172         struct drm_mode_set set = {
 173                 .crtc = crtc,
 174                 .fb = fb,
 175                 .mode = &crtc->mode,
 176                 .x = src_x >> 16,
 177                 .y = src_y >> 16,
 178         };
 179         struct drm_rect src = {
 180                 .x1 = src_x,
 181                 .y1 = src_y,
 182                 .x2 = src_x + src_w,
 183                 .y2 = src_y + src_h,
 184         };
 185         struct drm_rect dest = {
 186                 .x1 = crtc_x,
 187                 .y1 = crtc_y,
 188                 .x2 = crtc_x + crtc_w,
 189                 .y2 = crtc_y + crtc_h,
 190         };
 191         struct drm_device *dev = plane->dev;
 192         struct drm_connector **connector_list;
 193         int num_connectors, ret;
 194         bool visible;
 195
 196         if (drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev)))
 197                 return -EINVAL;
 198
 199         ret = drm_plane_helper_check_update(plane, crtc, fb,
 200                                             &src, &dest,
 201                                             DRM_MODE_ROTATE_0,
 202                                             DRM_PLANE_NO_SCALING,
 203                                             DRM_PLANE_NO_SCALING,
 204                                             false, false, &visible);
 205         if (ret)
 206                 return ret;
 207
 208         if (!visible)
 209                 /*
 210                  * Primary plane isn't visible.  Note that unless a driver
 211                  * provides their own disable function, this will just
 212                  * wind up returning -EINVAL to userspace.
 213                  */
 214                 return plane->funcs->disable_plane(plane, ctx);
 215
 216         /* Find current connectors for CRTC */
 217         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 218         BUG_ON(num_connectors == 0);
 219         connector_list = kcalloc(num_connectors, sizeof(*connector_list),
 220                                  GFP_KERNEL);
 221         if (!connector_list)
 222                 return -ENOMEM;
 223         get_connectors_for_crtc(crtc, connector_list, num_connectors);
 224
 225         set.connectors = connector_list;
 226         set.num_connectors = num_connectors;
 227
 228         /*
 229          * We call set_config() directly here rather than using
 230          * drm_mode_set_config_internal.  We're reprogramming the same
 231          * connectors that were already in use, so we shouldn't need the extra
 232          * cross-CRTC fb refcounting to accommodate stealing connectors.
 233          * drm_mode_setplane() already handles the basic refcounting for the
 234          * framebuffers involved in this operation.
 235          */
 236         ret = crtc->funcs->set_config(&set, ctx);
 237
 238         kfree(connector_list);
 239         return ret;
 240 }
 241 EXPORT_SYMBOL(drm_plane_helper_update_primary);
 242
 243 /**
 244  * drm_plane_helper_disable_primary - Helper for disabling primary planes
 245  * @plane: plane to disable
 246  * @ctx: modeset locking context
 247  *
 248  * This helper returns an error when trying to disable the primary
 249  * plane.
 250  *
 251  * This function is only useful for non-atomic modesetting. Don't use
 252  * it in new drivers.
 253  *
 254  * Returns:
 255  * An errno code.
 256  */
 257 int drm_plane_helper_disable_primary(struct drm_plane *plane,
 258                                      struct drm_modeset_acquire_ctx *ctx)
 259 {
 260         struct drm_device *dev = plane->dev;
 261
 262         drm_WARN_ON_ONCE(dev, drm_drv_uses_atomic_modeset(dev));
 263
 264         return -EINVAL;
 265 }
 266 EXPORT_SYMBOL(drm_plane_helper_disable_primary);
 267
 268 /**
 269  * drm_plane_helper_destroy() - Helper for primary plane destruction
 270  * @plane: plane to destroy
 271  *
 272  * Provides a default plane destroy handler for primary planes.  This handler
 273  * is called during CRTC destruction.  We disable the primary plane, remove
 274  * it from the DRM plane list, and deallocate the plane structure.
 275  */
 276 void drm_plane_helper_destroy(struct drm_plane *plane)
 277 {
 278         drm_plane_cleanup(plane);
 279         kfree(plane);
 280 }
 281 EXPORT_SYMBOL(drm_plane_helper_destroy);
 282
 283 /**
 284  * drm_plane_helper_atomic_check() - Helper to check plane atomic-state
 285  * @plane: plane to check
 286  * @state: atomic state object
 287  *
 288  * Provides a default plane-state check handler for planes whose atomic-state
 289  * scale and positioning are not expected to change since the plane is always
 290  * a fullscreen scanout buffer.
 291  *
 292  * This is often the case for the primary plane of simple framebuffers. See
 293  * also drm_crtc_helper_atomic_check() for the respective CRTC-state check
 294  * helper function.
 295  *
 296  * RETURNS:
 297  * Zero on success, or an errno code otherwise.
 298  */
 299 int drm_plane_helper_atomic_check(struct drm_plane *plane, struct drm_atomic_state *state)
 300 {
 301         struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
 302         struct drm_crtc *new_crtc = new_plane_state->crtc;
 303         struct drm_crtc_state *new_crtc_state = NULL;
 304
 305         if (new_crtc)
 306                 new_crtc_state = drm_atomic_get_new_crtc_state(state, new_crtc);
 307
 308         return drm_atomic_helper_check_plane_state(new_plane_state, new_crtc_state,
 309                                                    DRM_PLANE_NO_SCALING,
 310                                                    DRM_PLANE_NO_SCALING,
 311                                                    false, false);
 312 }
 313 EXPORT_SYMBOL(drm_plane_helper_atomic_check);