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_crtc.h"
  18 #include "drm_atomic.h"
  19 #include "drm_atomic_helper.h"
  20 #include "drm_crtc_helper.h"
  21 #include "drm_plane_helper.h"
  22 #include "drm_fb_cma_helper.h"
  23 #include "vc4_drv.h"
  24
  25 static void vc4_output_poll_changed(struct drm_device *dev)
  26 {
  27         struct vc4_dev *vc4 = to_vc4_dev(dev);
  28
  29         if (vc4->fbdev)
  30                 drm_fbdev_cma_hotplug_event(vc4->fbdev);
  31 }
  32
  33 struct vc4_commit {
  34         struct drm_device *dev;
  35         struct drm_atomic_state *state;
  36         struct vc4_seqno_cb cb;
  37 };
  38
  39 static void
  40 vc4_atomic_complete_commit(struct vc4_commit *c)
  41 {
  42         struct drm_atomic_state *state = c->state;
  43         struct drm_device *dev = state->dev;
  44         struct vc4_dev *vc4 = to_vc4_dev(dev);
  45
  46         drm_atomic_helper_commit_modeset_disables(dev, state);
  47
  48         drm_atomic_helper_commit_planes(dev, state, false);
  49
  50         drm_atomic_helper_commit_modeset_enables(dev, state);
  51
  52         drm_atomic_helper_wait_for_vblanks(dev, state);
  53
  54         drm_atomic_helper_cleanup_planes(dev, state);
  55
  56         drm_atomic_state_free(state);
  57
  58         up(&vc4->async_modeset);
  59
  60         kfree(c);
  61 }
  62
  63 static void
  64 vc4_atomic_complete_commit_seqno_cb(struct vc4_seqno_cb *cb)
  65 {
  66         struct vc4_commit *c = container_of(cb, struct vc4_commit, cb);
  67
  68         vc4_atomic_complete_commit(c);
  69 }
  70
  71 static struct vc4_commit *commit_init(struct drm_atomic_state *state)
  72 {
  73         struct vc4_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
  74
  75         if (!c)
  76                 return NULL;
  77         c->dev = state->dev;
  78         c->state = state;
  79
  80         return c;
  81 }
  82
  83 /**
  84  * vc4_atomic_commit - commit validated state object
  85  * @dev: DRM device
  86  * @state: the driver state object
  87  * @async: asynchronous commit
  88  *
  89  * This function commits a with drm_atomic_helper_check() pre-validated state
  90  * object. This can still fail when e.g. the framebuffer reservation fails. For
  91  * now this doesn't implement asynchronous commits.
  92  *
  93  * RETURNS
  94  * Zero for success or -errno.
  95  */
  96 static int vc4_atomic_commit(struct drm_device *dev,
  97                              struct drm_atomic_state *state,
  98                              bool async)
  99 {
 100         struct vc4_dev *vc4 = to_vc4_dev(dev);
 101         int ret;
 102         int i;
 103         uint64_t wait_seqno = 0;
 104         struct vc4_commit *c;
 105
 106         c = commit_init(state);
 107         if (!c)
 108                 return -ENOMEM;
 109
 110         /* Make sure that any outstanding modesets have finished. */
 111         ret = down_interruptible(&vc4->async_modeset);
 112         if (ret) {
 113                 kfree(c);
 114                 return ret;
 115         }
 116
 117         ret = drm_atomic_helper_prepare_planes(dev, state);
 118         if (ret) {
 119                 kfree(c);
 120                 up(&vc4->async_modeset);
 121                 return ret;
 122         }
 123
 124         for (i = 0; i < dev->mode_config.num_total_plane; i++) {
 125                 struct drm_plane *plane = state->planes[i];
 126                 struct drm_plane_state *new_state = state->plane_states[i];
 127
 128                 if (!plane)
 129                         continue;
 130
 131                 if ((plane->state->fb != new_state->fb) && new_state->fb) {
 132                         struct drm_gem_cma_object *cma_bo =
 133                                 drm_fb_cma_get_gem_obj(new_state->fb, 0);
 134                         struct vc4_bo *bo = to_vc4_bo(&cma_bo->base);
 135
 136                         wait_seqno = max(bo->seqno, wait_seqno);
 137                 }
 138         }
 139
 140         /*
 141          * This is the point of no return - everything below never fails except
 142          * when the hw goes bonghits. Which means we can commit the new state on
 143          * the software side now.
 144          */
 145
 146         drm_atomic_helper_swap_state(dev, state);
 147
 148         /*
 149          * Everything below can be run asynchronously without the need to grab
 150          * any modeset locks at all under one condition: It must be guaranteed
 151          * that the asynchronous work has either been cancelled (if the driver
 152          * supports it, which at least requires that the framebuffers get
 153          * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
 154          * before the new state gets committed on the software side with
 155          * drm_atomic_helper_swap_state().
 156          *
 157          * This scheme allows new atomic state updates to be prepared and
 158          * checked in parallel to the asynchronous completion of the previous
 159          * update. Which is important since compositors need to figure out the
 160          * composition of the next frame right after having submitted the
 161          * current layout.
 162          */
 163
 164         if (async) {
 165                 vc4_queue_seqno_cb(dev, &c->cb, wait_seqno,
 166                                    vc4_atomic_complete_commit_seqno_cb);
 167         } else {
 168                 vc4_wait_for_seqno(dev, wait_seqno, ~0ull, false);
 169                 vc4_atomic_complete_commit(c);
 170         }
 171
 172         return 0;
 173 }
 174
 175 static const struct drm_mode_config_funcs vc4_mode_funcs = {
 176         .output_poll_changed = vc4_output_poll_changed,
 177         .atomic_check = drm_atomic_helper_check,
 178         .atomic_commit = vc4_atomic_commit,
 179         .fb_create = drm_fb_cma_create,
 180 };
 181
 182 int vc4_kms_load(struct drm_device *dev)
 183 {
 184         struct vc4_dev *vc4 = to_vc4_dev(dev);
 185         int ret;
 186
 187         sema_init(&vc4->async_modeset, 1);
 188
 189         ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
 190         if (ret < 0) {
 191                 dev_err(dev->dev, "failed to initialize vblank\n");
 192                 return ret;
 193         }
 194
 195         dev->mode_config.max_width = 2048;
 196         dev->mode_config.max_height = 2048;
 197         dev->mode_config.funcs = &vc4_mode_funcs;
 198         dev->mode_config.preferred_depth = 24;
 199         dev->mode_config.async_page_flip = true;
 200
 201         dev->vblank_disable_allowed = true;
 202
 203         drm_mode_config_reset(dev);
 204
 205         vc4->fbdev = drm_fbdev_cma_init(dev, 32,
 206                                         dev->mode_config.num_crtc,
 207                                         dev->mode_config.num_connector);
 208         if (IS_ERR(vc4->fbdev))
 209                 vc4->fbdev = NULL;
 210
 211         drm_kms_helper_poll_init(dev);
 212
 213         return 0;
 214 }