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          * @event: Actual event which will be sent to userspace.
  52          */
  53         struct drm_event_vblank event;
  54 };
  55
  56 /**
  57  * struct drm_vblank_crtc - vblank tracking for a CRTC
  58  *
  59  * This structure tracks the vblank state for one CRTC.
  60  *
  61  * Note that for historical reasons - the vblank handling code is still shared
  62  * with legacy/non-kms drivers - this is a free-standing structure not directly
  63  * connected to &struct drm_crtc. But all public interface functions are taking
  64  * a &struct drm_crtc to hide this implementation detail.
  65  */
  66 struct drm_vblank_crtc {
  67         /**
  68          * @dev: Pointer to the &drm_device.
  69          */
  70         struct drm_device *dev;
  71         /**
  72          * @queue: Wait queue for vblank waiters.
  73          */
  74         wait_queue_head_t queue;        /**< VBLANK wait queue */
  75         /**
  76          * @disable_timer: Disable timer for the delayed vblank disabling
  77          * hysteresis logic. Vblank disabling is controlled through the
  78          * drm_vblank_offdelay module option and the setting of the
  79          * &drm_device.max_vblank_count value.
  80          */
  81         struct timer_list disable_timer;
  82
  83         /**
  84          * @seqlock: Protect vblank count and time.
  85          */
  86         seqlock_t seqlock;              /* protects vblank count and time */
  87
  88         /**
  89          * @count: Current software vblank counter.
  90          */
  91         u32 count;
  92         /**
  93          * @time: Vblank timestamp corresponding to @count.
  94          */
  95         struct timeval time;
  96
  97         /**
  98          * @refcount: Number of users/waiters of the vblank interrupt. Only when
  99          * this refcount reaches 0 can the hardware interrupt be disabled using
 100          * @disable_timer.
 101          */
 102         atomic_t refcount;              /* number of users of vblank interruptsper crtc */
 103         /**
 104          * @last: Protected by &drm_device.vbl_lock, used for wraparound handling.
 105          */
 106         u32 last;
 107         /**
 108          * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
 109          * For legacy driver bit 2 additionally tracks whether an additional
 110          * temporary vblank reference has been acquired to paper over the
 111          * hardware counter resetting/jumping. KMS drivers should instead just
 112          * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
 113          * save and restore the vblank count.
 114          */
 115         unsigned int inmodeset;         /* Display driver is setting mode */
 116         /**
 117          * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
 118          * structure.
 119          */
 120         unsigned int pipe;
 121         /**
 122          * @framedur_ns: Frame/Field duration in ns, used by
 123          * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 124          * drm_calc_timestamping_constants().
 125          */
 126         int framedur_ns;
 127         /**
 128          * @linedur_ns: Line duration in ns, used by
 129          * drm_calc_vbltimestamp_from_scanoutpos() and computed by
 130          * drm_calc_timestamping_constants().
 131          */
 132         int linedur_ns;
 133
 134         /**
 135          * @hwmode:
 136          *
 137          * Cache of the current hardware display mode. Only valid when @enabled
 138          * is set. This is used by helpers like
 139          * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the
 140          * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode,
 141          * because that one is really hard to get from interrupt context.
 142          */
 143         struct drm_display_mode hwmode;
 144
 145         /**
 146          * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
 147          * avoid double-disabling and hence corrupting saved state. Needed by
 148          * drivers not using atomic KMS, since those might go through their CRTC
 149          * disabling functions multiple times.
 150          */
 151         bool enabled;
 152 };
 153
 154 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
 155 u32 drm_crtc_vblank_count(struct drm_crtc *crtc);
 156 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
 157                                    struct timeval *vblanktime);
 158 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
 159                                struct drm_pending_vblank_event *e);
 160 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
 161                               struct drm_pending_vblank_event *e);
 162 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
 163 bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
 164 int drm_crtc_vblank_get(struct drm_crtc *crtc);
 165 void drm_crtc_vblank_put(struct drm_crtc *crtc);
 166 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
 167 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
 168 void drm_crtc_vblank_off(struct drm_crtc *crtc);
 169 void drm_crtc_vblank_reset(struct drm_crtc *crtc);
 170 void drm_crtc_vblank_on(struct drm_crtc *crtc);
 171 void drm_vblank_cleanup(struct drm_device *dev);
 172 u32 drm_accurate_vblank_count(struct drm_crtc *crtc);
 173
 174 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
 175                                            unsigned int pipe, int *max_error,
 176                                            struct timeval *vblank_time,
 177                                            bool in_vblank_irq);
 178 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
 179                                      const struct drm_display_mode *mode);
 180 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
 181 #endif