gpu/drm/drm_plane_helper.c

0001 /*
0002  * Copyright (C) 2014 Intel Corporation
0003  *
0004  * DRM universal plane helper functions
0005  *
0006  * Permission is hereby granted, free of charge, to any person obtaining a
0007  * copy of this software and associated documentation files (the "Software"),
0008  * to deal in the Software without restriction, including without limitation
0009  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0010  * and/or sell copies of the Software, and to permit persons to whom the
0011  * Software is furnished to do so, subject to the following conditions:
0012  *
0013  * The above copyright notice and this permission notice (including the next
0014  * paragraph) shall be included in all copies or substantial portions of the
0015  * Software.
0016  *
0017  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0018  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0019  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0020  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0021  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
0022  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
0023  * SOFTWARE.
0024  */
0025
0026 #include <linux/list.h>
0027
0028 #include <drm/drm_atomic.h>
0029 #include <drm/drm_atomic_helper.h>
0030 #include <drm/drm_atomic_uapi.h>
0031 #include <drm/drm_crtc_helper.h>
0032 #include <drm/drm_device.h>
0033 #include <drm/drm_encoder.h>
0034 #include <drm/drm_plane_helper.h>
0035 #include <drm/drm_rect.h>
0036
0037 #define SUBPIXEL_MASK 0xffff
0038
0039 /**
0040  * DOC: overview
0041  *
0042  * This helper library has two parts. The first part has support to implement
0043  * primary plane support on top of the normal CRTC configuration interface.
0044  * Since the legacy &drm_mode_config_funcs.set_config interface ties the primary
0045  * plane together with the CRTC state this does not allow userspace to disable
0046  * the primary plane itself. The default primary plane only expose XRBG8888 and
0047  * ARGB8888 as valid pixel formats for the attached framebuffer.
0048  *
0049  * Drivers are highly recommended to implement proper support for primary
0050  * planes, and newly merged drivers must not rely upon these transitional
0051  * helpers.
0052  *
0053  * The second part also implements transitional helpers which allow drivers to
0054  * gradually switch to the atomic helper infrastructure for plane updates. Once
0055  * that switch is complete drivers shouldn't use these any longer, instead using
0056  * the proper legacy implementations for update and disable plane hooks provided
0057  * by the atomic helpers.
0058  *
0059  * Again drivers are strongly urged to switch to the new interfaces.
0060  *
0061  * The plane helpers share the function table structures with other helpers,
0062  * specifically also the atomic helpers. See &struct drm_plane_helper_funcs for
0063  * the details.
0064  */
0065
0066 /*
0067  * Returns the connectors currently associated with a CRTC.  This function
0068  * should be called twice:  once with a NULL connector list to retrieve
0069  * the list size, and once with the properly allocated list to be filled in.
0070  */
0071 static int get_connectors_for_crtc(struct drm_crtc *crtc,
0072                    struct drm_connector **connector_list,
0073                    int num_connectors)
0074 {
0075     struct drm_device *dev = crtc->dev;
0076     struct drm_connector *connector;
0077     struct drm_connector_list_iter conn_iter;
0078     int count = 0;
0079
0080     /*
0081      * Note: Once we change the plane hooks to more fine-grained locking we
0082      * need to grab the connection_mutex here to be able to make these
0083      * checks.
0084      */
0085     WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
0086
0087     drm_connector_list_iter_begin(dev, &conn_iter);
0088     drm_for_each_connector_iter(connector, &conn_iter) {
0089         if (connector->encoder && connector->encoder->crtc == crtc) {
0090             if (connector_list != NULL && count < num_connectors)
0091                 *(connector_list++) = connector;
0092
0093             count++;
0094         }
0095     }
0096     drm_connector_list_iter_end(&conn_iter);
0097
0098     return count;
0099 }
0100
0101 static int drm_plane_helper_check_update(struct drm_plane *plane,
0102                      struct drm_crtc *crtc,
0103                      struct drm_framebuffer *fb,
0104                      struct drm_rect *src,
0105                      struct drm_rect *dst,
0106                      unsigned int rotation,
0107                      int min_scale,
0108                      int max_scale,
0109                      bool can_position,
0110                      bool can_update_disabled,
0111                      bool *visible)
0112 {
0113     struct drm_plane_state plane_state = {
0114         .plane = plane,
0115         .crtc = crtc,
0116         .fb = fb,
0117         .src_x = src->x1,
0118         .src_y = src->y1,
0119         .src_w = drm_rect_width(src),
0120         .src_h = drm_rect_height(src),
0121         .crtc_x = dst->x1,
0122         .crtc_y = dst->y1,
0123         .crtc_w = drm_rect_width(dst),
0124         .crtc_h = drm_rect_height(dst),
0125         .rotation = rotation,
0126     };
0127     struct drm_crtc_state crtc_state = {
0128         .crtc = crtc,
0129         .enable = crtc->enabled,
0130         .mode = crtc->mode,
0131     };
0132     int ret;
0133
0134     ret = drm_atomic_helper_check_plane_state(&plane_state, &crtc_state,
0135                           min_scale, max_scale,
0136                           can_position,
0137                           can_update_disabled);
0138     if (ret)
0139         return ret;
0140
0141     *src = plane_state.src;
0142     *dst = plane_state.dst;
0143     *visible = plane_state.visible;
0144
0145     return 0;
0146 }
0147
0148 static int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
0149                      struct drm_framebuffer *fb,
0150                      int crtc_x, int crtc_y,
0151                      unsigned int crtc_w, unsigned int crtc_h,
0152                      uint32_t src_x, uint32_t src_y,
0153                      uint32_t src_w, uint32_t src_h,
0154                      struct drm_modeset_acquire_ctx *ctx)
0155 {
0156     struct drm_mode_set set = {
0157         .crtc = crtc,
0158         .fb = fb,
0159         .mode = &crtc->mode,
0160         .x = src_x >> 16,
0161         .y = src_y >> 16,
0162     };
0163     struct drm_rect src = {
0164         .x1 = src_x,
0165         .y1 = src_y,
0166         .x2 = src_x + src_w,
0167         .y2 = src_y + src_h,
0168     };
0169     struct drm_rect dest = {
0170         .x1 = crtc_x,
0171         .y1 = crtc_y,
0172         .x2 = crtc_x + crtc_w,
0173         .y2 = crtc_y + crtc_h,
0174     };
0175     struct drm_connector **connector_list;
0176     int num_connectors, ret;
0177     bool visible;
0178
0179     ret = drm_plane_helper_check_update(plane, crtc, fb,
0180                         &src, &dest,
0181                         DRM_MODE_ROTATE_0,
0182                         DRM_PLANE_HELPER_NO_SCALING,
0183                         DRM_PLANE_HELPER_NO_SCALING,
0184                         false, false, &visible);
0185     if (ret)
0186         return ret;
0187
0188     if (!visible)
0189         /*
0190          * Primary plane isn't visible.  Note that unless a driver
0191          * provides their own disable function, this will just
0192          * wind up returning -EINVAL to userspace.
0193          */
0194         return plane->funcs->disable_plane(plane, ctx);
0195
0196     /* Find current connectors for CRTC */
0197     num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
0198     BUG_ON(num_connectors == 0);
0199     connector_list = kcalloc(num_connectors, sizeof(*connector_list),
0200                  GFP_KERNEL);
0201     if (!connector_list)
0202         return -ENOMEM;
0203     get_connectors_for_crtc(crtc, connector_list, num_connectors);
0204
0205     set.connectors = connector_list;
0206     set.num_connectors = num_connectors;
0207
0208     /*
0209      * We call set_config() directly here rather than using
0210      * drm_mode_set_config_internal.  We're reprogramming the same
0211      * connectors that were already in use, so we shouldn't need the extra
0212      * cross-CRTC fb refcounting to accommodate stealing connectors.
0213      * drm_mode_setplane() already handles the basic refcounting for the
0214      * framebuffers involved in this operation.
0215      */
0216     ret = crtc->funcs->set_config(&set, ctx);
0217
0218     kfree(connector_list);
0219     return ret;
0220 }
0221
0222 static int drm_primary_helper_disable(struct drm_plane *plane,
0223                       struct drm_modeset_acquire_ctx *ctx)
0224 {
0225     return -EINVAL;
0226 }
0227
0228 /**
0229  * drm_primary_helper_destroy() - Helper for primary plane destruction
0230  * @plane: plane to destroy
0231  *
0232  * Provides a default plane destroy handler for primary planes.  This handler
0233  * is called during CRTC destruction.  We disable the primary plane, remove
0234  * it from the DRM plane list, and deallocate the plane structure.
0235  */
0236 void drm_primary_helper_destroy(struct drm_plane *plane)
0237 {
0238     drm_plane_cleanup(plane);
0239     kfree(plane);
0240 }
0241 EXPORT_SYMBOL(drm_primary_helper_destroy);
0242
0243 const struct drm_plane_funcs drm_primary_helper_funcs = {
0244     .update_plane = drm_primary_helper_update,
0245     .disable_plane = drm_primary_helper_disable,
0246     .destroy = drm_primary_helper_destroy,
0247 };
0248 EXPORT_SYMBOL(drm_primary_helper_funcs);