include/drm/drm_vblank.h

   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
  35 struct drm_device;
  36 struct drm_crtc;
  37
  38 /**
  39  * struct drm_pending_vblank_event - pending vblank event tracking
  40  */
  41 struct 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  */
  90 struct 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;        /**< VBLANK wait 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;              /* protects vblank count and time */
 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;              /* number of users of vblank interruptsper crtc */
 127         /**
 128          * @last: Protected by &drm_device.vbl_lock, used for wraparound handling.
 129          */
 130         u32 last;
 131         /**
 132          * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
 133          * For legacy driver bit 2 additionally tracks whether an additional
 134          * temporary vblank reference has been acquired to paper over the
 135          * hardware counter resetting/jumping. KMS drivers should instead just
 136          * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
 137          * save and restore the vblank count.
 138          */
 139         unsigned int inmodeset;         /* Display driver is setting mode */
 140         /**
 141          * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
 142          * structure.
 143          */
 144         unsigned int pipe;
 145         /**
 146          * @framedur_ns: Frame/Field duration in ns, used by
 147          * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 148          * drm_calc_timestamping_constants().
 149          */
 150         int framedur_ns;
 151         /**
 152          * @linedur_ns: Line duration in ns, used by
 153          * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 154          * drm_calc_timestamping_constants().
 155          */
 156         int linedur_ns;
 157
 158         /**
 159          * @hwmode:
 160          *
 161          * Cache of the current hardware display mode. Only valid when @enabled
 162          * is set. This is used by helpers like
 163          * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the
 164          * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode,
 165          * because that one is really hard to get from interrupt context.
 166          */
 167         struct drm_display_mode hwmode;
 168
 169         /**
 170          * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
 171          * avoid double-disabling and hence corrupting saved state. Needed by
 172          * drivers not using atomic KMS, since those might go through their CRTC
 173          * disabling functions multiple times.
 174          */
 175         bool enabled;
 176 };
 177
 178 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
 179 u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
 180 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
 181                                    ktime_t *vblanktime);
 182 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
 183                                struct drm_pending_vblank_event *e);
 184 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
 185                               struct drm_pending_vblank_event *e);
 186 void drm_vblank_set_event(struct drm_pending_vblank_event *e,
 187                           u64 *seq,
 188                           ktime_t *now);
 189 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
 190 bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
 191 int drm_crtc_vblank_get(struct drm_crtc *crtc);
 192 void drm_crtc_vblank_put(struct drm_crtc *crtc);
 193 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
 194 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
 195 void drm_crtc_vblank_off(struct drm_crtc *crtc);
 196 void drm_crtc_vblank_reset(struct drm_crtc *crtc);
 197 void drm_crtc_vblank_on(struct drm_crtc *crtc);
 198 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);
 199 void drm_vblank_restore(struct drm_device *dev, unsigned int pipe);
 200 void drm_crtc_vblank_restore(struct drm_crtc *crtc);
 201
 202 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
 203                                            unsigned int pipe, int *max_error,
 204                                            ktime_t *vblank_time,
 205                                            bool in_vblank_irq);
 206 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
 207                                      const struct drm_display_mode *mode);
 208 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
 209 #endif