LXR linux/include/drm/drm

   1/*
   2 * Copyright 2016 Intel Corp.
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice (including the next
  12 * paragraph) shall be included in all copies or substantial portions of the
  13 * Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21 * OTHER DEALINGS IN THE SOFTWARE.
  22 */
  23
  24#ifndef _DRM_VBLANK_H_
  25#define _DRM_VBLANK_H_
  26
  27#include <linux/seqlock.h>
  28#include <linux/idr.h>
  29#include <linux/poll.h>
  30
  31#include <drm/drm_file.h>
  32#include <drm/drm_modes.h>
  33#include <uapi/drm/drm.h>
  34
  35struct drm_device;
  36struct drm_crtc;
  37
  38/**
  39 * struct drm_pending_vblank_event - pending vblank event tracking
  40 */
  41struct drm_pending_vblank_event {
  42        /**
  43         * @base: Base structure for tracking pending DRM events.
  44         */
  45        struct drm_pending_event base;
  46        /**
  47         * @pipe: drm_crtc_index() of the &drm_crtc this event is for.
  48         */
  49        unsigned int pipe;
  50        /**
  51         * @sequence: frame event should be triggered at
  52         */
  53        u64 sequence;
  54        /**
  55         * @event: Actual event which will be sent to userspace.
  56         */
  57        union {
  58                /**
  59                 * @event.base: DRM event base class.
  60                 */
  61                struct drm_event base;
  62
  63                /**
  64                 * @event.vbl:
  65                 *
  66                 * Event payload for vblank events, requested through
  67                 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also
  68                 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace
  69                 * should use MODE_QUEUE_SEQUENCE and &event.seq instead.
  70                 */
  71                struct drm_event_vblank vbl;
  72
  73                /**
  74                 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL.
  75                 */
  76                struct drm_event_crtc_sequence seq;
  77        } event;
  78};
  79
  80/**
  81 * struct drm_vblank_crtc - vblank tracking for a CRTC
  82 *
  83 * This structure tracks the vblank state for one CRTC.
  84 *
  85 * Note that for historical reasons - the vblank handling code is still shared
  86 * with legacy/non-kms drivers - this is a free-standing structure not directly
  87 * connected to &struct drm_crtc. But all public interface functions are taking
  88 * a &struct drm_crtc to hide this implementation detail.
  89 */
  90struct drm_vblank_crtc {
  91        /**
  92         * @dev: Pointer to the &drm_device.
  93         */
  94        struct drm_device *dev;
  95        /**
  96         * @queue: Wait queue for vblank waiters.
  97         */
  98        wait_queue_head_t queue;
  99        /**
 100         * @disable_timer: Disable timer for the delayed vblank disabling
 101         * hysteresis logic. Vblank disabling is controlled through the
 102         * drm_vblank_offdelay module option and the setting of the
 103         * &drm_device.max_vblank_count value.
 104         */
 105        struct timer_list disable_timer;
 106
 107        /**
 108         * @seqlock: Protect vblank count and time.
 109         */
 110        seqlock_t seqlock;
 111
 112        /**
 113         * @count: Current software vblank counter.
 114         */
 115        u64 count;
 116        /**
 117         * @time: Vblank timestamp corresponding to @count.
 118         */
 119        ktime_t time;
 120
 121        /**
 122         * @refcount: Number of users/waiters of the vblank interrupt. Only when
 123         * this refcount reaches 0 can the hardware interrupt be disabled using
 124         * @disable_timer.
 125         */
 126        atomic_t refcount;
 127        /**
 128         * @last: Protected by &drm_device.vbl_lock, used for wraparound handling.
 129         */
 130        u32 last;
 131        /**
 132         * @max_vblank_count:
 133         *
 134         * Maximum value of the vblank registers for this crtc. This value +1
 135         * will result in a wrap-around of the vblank register. It is used
 136         * by the vblank core to handle wrap-arounds.
 137         *
 138         * If set to zero the vblank core will try to guess the elapsed vblanks
 139         * between times when the vblank interrupt is disabled through
 140         * high-precision timestamps. That approach is suffering from small
 141         * races and imprecision over longer time periods, hence exposing a
 142         * hardware vblank counter is always recommended.
 143         *
 144         * This is the runtime configurable per-crtc maximum set through
 145         * drm_crtc_set_max_vblank_count(). If this is used the driver
 146         * must leave the device wide &drm_device.max_vblank_count at zero.
 147         *
 148         * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set.
 149         */
 150        u32 max_vblank_count;
 151        /**
 152         * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
 153         * For legacy driver bit 2 additionally tracks whether an additional
 154         * temporary vblank reference has been acquired to paper over the
 155         * hardware counter resetting/jumping. KMS drivers should instead just
 156         * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
 157         * save and restore the vblank count.
 158         */
 159        unsigned int inmodeset;
 160        /**
 161         * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
 162         * structure.
 163         */
 164        unsigned int pipe;
 165        /**
 166         * @framedur_ns: Frame/Field duration in ns, used by
 167         * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 168         * drm_calc_timestamping_constants().
 169         */
 170        int framedur_ns;
 171        /**
 172         * @linedur_ns: Line duration in ns, used by
 173         * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 174         * drm_calc_timestamping_constants().
 175         */
 176        int linedur_ns;
 177
 178        /**
 179         * @hwmode:
 180         *
 181         * Cache of the current hardware display mode. Only valid when @enabled
 182         * is set. This is used by helpers like
 183         * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the
 184         * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode,
 185         * because that one is really hard to get from interrupt context.
 186         */
 187        struct drm_display_mode hwmode;
 188
 189        /**
 190         * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
 191         * avoid double-disabling and hence corrupting saved state. Needed by
 192         * drivers not using atomic KMS, since those might go through their CRTC
 193         * disabling functions multiple times.
 194         */
 195        bool enabled;
 196};
 197
 198int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
 199u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
 200u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
 201                                   ktime_t *vblanktime);
 202void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
 203                               struct drm_pending_vblank_event *e);
 204void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
 205                              struct drm_pending_vblank_event *e);
 206void drm_vblank_set_event(struct drm_pending_vblank_event *e,
 207                          u64 *seq,
 208                          ktime_t *now);
 209bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
 210bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
 211int drm_crtc_vblank_get(struct drm_crtc *crtc);
 212void drm_crtc_vblank_put(struct drm_crtc *crtc);
 213void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
 214void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
 215void drm_crtc_vblank_off(struct drm_crtc *crtc);
 216void drm_crtc_vblank_reset(struct drm_crtc *crtc);
 217void drm_crtc_vblank_on(struct drm_crtc *crtc);
 218u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);
 219void drm_vblank_restore(struct drm_device *dev, unsigned int pipe);
 220void drm_crtc_vblank_restore(struct drm_crtc *crtc);
 221
 222bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
 223                                           unsigned int pipe, int *max_error,
 224                                           ktime_t *vblank_time,
 225                                           bool in_vblank_irq);
 226void drm_calc_timestamping_constants(struct drm_crtc *crtc,
 227                                     const struct drm_display_mode *mode);
 228wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
 229void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc,
 230                                   u32 max_vblank_count);
 231#endif
 232