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_cma_helper.h>
  23 #include <drm/drm_gem_framebuffer_helper.h>
  24 #include "vc4_drv.h"
  25
  26 static void vc4_output_poll_changed(struct drm_device *dev)
  27 {
  28         struct vc4_dev *vc4 = to_vc4_dev(dev);
  29
  30         drm_fbdev_cma_hotplug_event(vc4->fbdev);
  31 }
  32
  33 static void
  34 vc4_atomic_complete_commit(struct drm_atomic_state *state)
  35 {
  36         struct drm_device *dev = state->dev;
  37         struct vc4_dev *vc4 = to_vc4_dev(dev);
  38
  39         drm_atomic_helper_wait_for_fences(dev, state, false);
  40
  41         drm_atomic_helper_wait_for_dependencies(state);
  42
  43         drm_atomic_helper_commit_modeset_disables(dev, state);
  44
  45         drm_atomic_helper_commit_planes(dev, state, 0);
  46
  47         drm_atomic_helper_commit_modeset_enables(dev, state);
  48
  49         /* Make sure that drm_atomic_helper_wait_for_vblanks()
  50          * actually waits for vblank.  If we're doing a full atomic
  51          * modeset (as opposed to a vc4_update_plane() short circuit),
  52          * then we need to wait for scanout to be done with our
  53          * display lists before we free it and potentially reallocate
  54          * and overwrite the dlist memory with a new modeset.
  55          */
  56         state->legacy_cursor_update = false;
  57
  58         drm_atomic_helper_commit_hw_done(state);
  59
  60         drm_atomic_helper_wait_for_vblanks(dev, state);
  61
  62         drm_atomic_helper_cleanup_planes(dev, state);
  63
  64         drm_atomic_helper_commit_cleanup_done(state);
  65
  66         drm_atomic_state_put(state);
  67
  68         up(&vc4->async_modeset);
  69 }
  70
  71 static void commit_work(struct work_struct *work)
  72 {
  73         struct drm_atomic_state *state = container_of(work,
  74                                                       struct drm_atomic_state,
  75                                                       commit_work);
  76         vc4_atomic_complete_commit(state);
  77 }
  78
  79 /**
  80  * vc4_atomic_commit - commit validated state object
  81  * @dev: DRM device
  82  * @state: the driver state object
  83  * @nonblock: nonblocking commit
  84  *
  85  * This function commits a with drm_atomic_helper_check() pre-validated state
  86  * object. This can still fail when e.g. the framebuffer reservation fails. For
  87  * now this doesn't implement asynchronous commits.
  88  *
  89  * RETURNS
  90  * Zero for success or -errno.
  91  */
  92 static int vc4_atomic_commit(struct drm_device *dev,
  93                              struct drm_atomic_state *state,
  94                              bool nonblock)
  95 {
  96         struct vc4_dev *vc4 = to_vc4_dev(dev);
  97         int ret;
  98
  99         ret = drm_atomic_helper_setup_commit(state, nonblock);
 100         if (ret)
 101                 return ret;
 102
 103         INIT_WORK(&state->commit_work, commit_work);
 104
 105         ret = down_interruptible(&vc4->async_modeset);
 106         if (ret)
 107                 return ret;
 108
 109         ret = drm_atomic_helper_prepare_planes(dev, state);
 110         if (ret) {
 111                 up(&vc4->async_modeset);
 112                 return ret;
 113         }
 114
 115         if (!nonblock) {
 116                 ret = drm_atomic_helper_wait_for_fences(dev, state, true);
 117                 if (ret) {
 118                         drm_atomic_helper_cleanup_planes(dev, state);
 119                         up(&vc4->async_modeset);
 120                         return ret;
 121                 }
 122         }
 123
 124         /*
 125          * This is the point of no return - everything below never fails except
 126          * when the hw goes bonghits. Which means we can commit the new state on
 127          * the software side now.
 128          */
 129
 130         BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
 131
 132         /*
 133          * Everything below can be run asynchronously without the need to grab
 134          * any modeset locks at all under one condition: It must be guaranteed
 135          * that the asynchronous work has either been cancelled (if the driver
 136          * supports it, which at least requires that the framebuffers get
 137          * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
 138          * before the new state gets committed on the software side with
 139          * drm_atomic_helper_swap_state().
 140          *
 141          * This scheme allows new atomic state updates to be prepared and
 142          * checked in parallel to the asynchronous completion of the previous
 143          * update. Which is important since compositors need to figure out the
 144          * composition of the next frame right after having submitted the
 145          * current layout.
 146          */
 147
 148         drm_atomic_state_get(state);
 149         if (nonblock)
 150                 queue_work(system_unbound_wq, &state->commit_work);
 151         else
 152                 vc4_atomic_complete_commit(state);
 153
 154         return 0;
 155 }
 156
 157 static struct drm_framebuffer *vc4_fb_create(struct drm_device *dev,
 158                                              struct drm_file *file_priv,
 159                                              const struct drm_mode_fb_cmd2 *mode_cmd)
 160 {
 161         struct drm_mode_fb_cmd2 mode_cmd_local;
 162
 163         /* If the user didn't specify a modifier, use the
 164          * vc4_set_tiling_ioctl() state for the BO.
 165          */
 166         if (!(mode_cmd->flags & DRM_MODE_FB_MODIFIERS)) {
 167                 struct drm_gem_object *gem_obj;
 168                 struct vc4_bo *bo;
 169
 170                 gem_obj = drm_gem_object_lookup(file_priv,
 171                                                 mode_cmd->handles[0]);
 172                 if (!gem_obj) {
 173                         DRM_DEBUG("Failed to look up GEM BO %d\n",
 174                                   mode_cmd->handles[0]);
 175                         return ERR_PTR(-ENOENT);
 176                 }
 177                 bo = to_vc4_bo(gem_obj);
 178
 179                 mode_cmd_local = *mode_cmd;
 180
 181                 if (bo->t_format) {
 182                         mode_cmd_local.modifier[0] =
 183                                 DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED;
 184                 } else {
 185                         mode_cmd_local.modifier[0] = DRM_FORMAT_MOD_NONE;
 186                 }
 187
 188                 drm_gem_object_put_unlocked(gem_obj);
 189
 190                 mode_cmd = &mode_cmd_local;
 191         }
 192
 193         return drm_gem_fb_create(dev, file_priv, mode_cmd);
 194 }
 195
 196 static const struct drm_mode_config_funcs vc4_mode_funcs = {
 197         .output_poll_changed = vc4_output_poll_changed,
 198         .atomic_check = drm_atomic_helper_check,
 199         .atomic_commit = vc4_atomic_commit,
 200         .fb_create = vc4_fb_create,
 201 };
 202
 203 int vc4_kms_load(struct drm_device *dev)
 204 {
 205         struct vc4_dev *vc4 = to_vc4_dev(dev);
 206         int ret;
 207
 208         sema_init(&vc4->async_modeset, 1);
 209
 210         /* Set support for vblank irq fast disable, before drm_vblank_init() */
 211         dev->vblank_disable_immediate = true;
 212
 213         ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
 214         if (ret < 0) {
 215                 dev_err(dev->dev, "failed to initialize vblank\n");
 216                 return ret;
 217         }
 218
 219         dev->mode_config.max_width = 2048;
 220         dev->mode_config.max_height = 2048;
 221         dev->mode_config.funcs = &vc4_mode_funcs;
 222         dev->mode_config.preferred_depth = 24;
 223         dev->mode_config.async_page_flip = true;
 224
 225         drm_mode_config_reset(dev);
 226
 227         if (dev->mode_config.num_connector) {
 228                 vc4->fbdev = drm_fbdev_cma_init(dev, 32,
 229                                                 dev->mode_config.num_connector);
 230                 if (IS_ERR(vc4->fbdev))
 231                         vc4->fbdev = NULL;
 232         }
 233
 234         drm_kms_helper_poll_init(dev);
 235
 236         return 0;
 237 }