drivers/gpu/drm/vc4/vc4_kms.c

   1 /*
   2  * Copyright (C) 2015 Broadcom
   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 version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 /**
  10  * DOC: VC4 KMS
  11  *
  12  * This is the general code for implementing KMS mode setting that
  13  * doesn't clearly associate with any of the other objects (plane,
  14  * crtc, HDMI encoder).
  15  */
  16
  17 #include <drm/drm_crtc.h>
  18 #include <drm/drm_atomic.h>
  19 #include <drm/drm_atomic_helper.h>
  20 #include <drm/drm_crtc_helper.h>
  21 #include <drm/drm_plane_helper.h>
  22 #include <drm/drm_fb_helper.h>
  23 #include <drm/drm_fb_cma_helper.h>
  24 #include <drm/drm_gem_framebuffer_helper.h>
  25 #include "vc4_drv.h"
  26
  27 static void
  28 vc4_atomic_complete_commit(struct drm_atomic_state *state)
  29 {
  30         struct drm_device *dev = state->dev;
  31         struct vc4_dev *vc4 = to_vc4_dev(dev);
  32
  33         drm_atomic_helper_wait_for_fences(dev, state, false);
  34
  35         drm_atomic_helper_wait_for_dependencies(state);
  36
  37         drm_atomic_helper_commit_modeset_disables(dev, state);
  38
  39         drm_atomic_helper_commit_planes(dev, state, 0);
  40
  41         drm_atomic_helper_commit_modeset_enables(dev, state);
  42
  43         /* Make sure that drm_atomic_helper_wait_for_vblanks()
  44          * actually waits for vblank.  If we're doing a full atomic
  45          * modeset (as opposed to a vc4_update_plane() short circuit),
  46          * then we need to wait for scanout to be done with our
  47          * display lists before we free it and potentially reallocate
  48          * and overwrite the dlist memory with a new modeset.
  49          */
  50         state->legacy_cursor_update = false;
  51
  52         drm_atomic_helper_commit_hw_done(state);
  53
  54         drm_atomic_helper_wait_for_vblanks(dev, state);
  55
  56         drm_atomic_helper_cleanup_planes(dev, state);
  57
  58         drm_atomic_helper_commit_cleanup_done(state);
  59
  60         drm_atomic_state_put(state);
  61
  62         up(&vc4->async_modeset);
  63 }
  64
  65 static void commit_work(struct work_struct *work)
  66 {
  67         struct drm_atomic_state *state = container_of(work,
  68                                                       struct drm_atomic_state,
  69                                                       commit_work);
  70         vc4_atomic_complete_commit(state);
  71 }
  72
  73 /**
  74  * vc4_atomic_commit - commit validated state object
  75  * @dev: DRM device
  76  * @state: the driver state object
  77  * @nonblock: nonblocking commit
  78  *
  79  * This function commits a with drm_atomic_helper_check() pre-validated state
  80  * object. This can still fail when e.g. the framebuffer reservation fails. For
  81  * now this doesn't implement asynchronous commits.
  82  *
  83  * RETURNS
  84  * Zero for success or -errno.
  85  */
  86 static int vc4_atomic_commit(struct drm_device *dev,
  87                              struct drm_atomic_state *state,
  88                              bool nonblock)
  89 {
  90         struct vc4_dev *vc4 = to_vc4_dev(dev);
  91         int ret;
  92
  93         ret = drm_atomic_helper_setup_commit(state, nonblock);
  94         if (ret)
  95                 return ret;
  96
  97         INIT_WORK(&state->commit_work, commit_work);
  98
  99         ret = down_interruptible(&vc4->async_modeset);
 100         if (ret)
 101                 return ret;
 102
 103         ret = drm_atomic_helper_prepare_planes(dev, state);
 104         if (ret) {
 105                 up(&vc4->async_modeset);
 106                 return ret;
 107         }
 108
 109         if (!nonblock) {
 110                 ret = drm_atomic_helper_wait_for_fences(dev, state, true);
 111                 if (ret) {
 112                         drm_atomic_helper_cleanup_planes(dev, state);
 113                         up(&vc4->async_modeset);
 114                         return ret;
 115                 }
 116         }
 117
 118         /*
 119          * This is the point of no return - everything below never fails except
 120          * when the hw goes bonghits. Which means we can commit the new state on
 121          * the software side now.
 122          */
 123
 124         BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
 125
 126         /*
 127          * Everything below can be run asynchronously without the need to grab
 128          * any modeset locks at all under one condition: It must be guaranteed
 129          * that the asynchronous work has either been cancelled (if the driver
 130          * supports it, which at least requires that the framebuffers get
 131          * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
 132          * before the new state gets committed on the software side with
 133          * drm_atomic_helper_swap_state().
 134          *
 135          * This scheme allows new atomic state updates to be prepared and
 136          * checked in parallel to the asynchronous completion of the previous
 137          * update. Which is important since compositors need to figure out the
 138          * composition of the next frame right after having submitted the
 139          * current layout.
 140          */
 141
 142         drm_atomic_state_get(state);
 143         if (nonblock)
 144                 queue_work(system_unbound_wq, &state->commit_work);
 145         else
 146                 vc4_atomic_complete_commit(state);
 147
 148         return 0;
 149 }
 150
 151 static struct drm_framebuffer *vc4_fb_create(struct drm_device *dev,
 152                                              struct drm_file *file_priv,
 153                                              const struct drm_mode_fb_cmd2 *mode_cmd)
 154 {
 155         struct drm_mode_fb_cmd2 mode_cmd_local;
 156
 157         /* If the user didn't specify a modifier, use the
 158          * vc4_set_tiling_ioctl() state for the BO.
 159          */
 160         if (!(mode_cmd->flags & DRM_MODE_FB_MODIFIERS)) {
 161                 struct drm_gem_object *gem_obj;
 162                 struct vc4_bo *bo;
 163
 164                 gem_obj = drm_gem_object_lookup(file_priv,
 165                                                 mode_cmd->handles[0]);
 166                 if (!gem_obj) {
 167                         DRM_DEBUG("Failed to look up GEM BO %d\n",
 168                                   mode_cmd->handles[0]);
 169                         return ERR_PTR(-ENOENT);
 170                 }
 171                 bo = to_vc4_bo(gem_obj);
 172
 173                 mode_cmd_local = *mode_cmd;
 174
 175                 if (bo->t_format) {
 176                         mode_cmd_local.modifier[0] =
 177                                 DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
 178                 } else {
 179                         mode_cmd_local.modifier[0] = DRM_FORMAT_MOD_NONE;
 180                 }
 181
 182                 drm_gem_object_put_unlocked(gem_obj);
 183
 184                 mode_cmd = &mode_cmd_local;
 185         }
 186
 187         return drm_gem_fb_create(dev, file_priv, mode_cmd);
 188 }
 189
 190 static const struct drm_mode_config_funcs vc4_mode_funcs = {
 191         .output_poll_changed = drm_fb_helper_output_poll_changed,
 192         .atomic_check = drm_atomic_helper_check,
 193         .atomic_commit = vc4_atomic_commit,
 194         .fb_create = vc4_fb_create,
 195 };
 196
 197 int vc4_kms_load(struct drm_device *dev)
 198 {
 199         struct vc4_dev *vc4 = to_vc4_dev(dev);
 200         int ret;
 201
 202         sema_init(&vc4->async_modeset, 1);
 203
 204         /* Set support for vblank irq fast disable, before drm_vblank_init() */
 205         dev->vblank_disable_immediate = true;
 206
 207         ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
 208         if (ret < 0) {
 209                 dev_err(dev->dev, "failed to initialize vblank\n");
 210                 return ret;
 211         }
 212
 213         dev->mode_config.max_width = 2048;
 214         dev->mode_config.max_height = 2048;
 215         dev->mode_config.funcs = &vc4_mode_funcs;
 216         dev->mode_config.preferred_depth = 24;
 217         dev->mode_config.async_page_flip = true;
 218
 219         drm_mode_config_reset(dev);
 220
 221         if (dev->mode_config.num_connector)
 222                 drm_fb_cma_fbdev_init(dev, 32, 0);
 223
 224         drm_kms_helper_poll_init(dev);
 225
 226         return 0;
 227 }