drm_vblank.h revision 1.8
1 /* $NetBSD: drm_vblank.h,v 1.8 2021/12/19 01:58:04 riastradh Exp $ */ 2 3 /* 4 * Copyright 2016 Intel Corp. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 23 * OTHER DEALINGS IN THE SOFTWARE. 24 */ 25 26 #ifndef _DRM_VBLANK_H_ 27 #define _DRM_VBLANK_H_ 28 29 #include <linux/seqlock.h> 30 #include <linux/idr.h> 31 #include <linux/poll.h> 32 #include <linux/timer.h> 33 #include <linux/ktime.h> 34 35 #include <drm/drm_file.h> 36 #include <drm/drm_modes.h> 37 38 #ifdef __NetBSD__ /* XXX */ 39 #include <drm/drm_wait_netbsd.h> 40 #endif 41 42 #ifdef __NetBSD__ /* XXX */ 43 #include <drm/drm_wait_netbsd.h> 44 #endif 45 46 struct drm_device; 47 struct drm_crtc; 48 49 /** 50 * struct drm_pending_vblank_event - pending vblank event tracking 51 */ 52 struct drm_pending_vblank_event { 53 /** 54 * @base: Base structure for tracking pending DRM events. 55 */ 56 struct drm_pending_event base; 57 /** 58 * @pipe: drm_crtc_index() of the &drm_crtc this event is for. 59 */ 60 unsigned int pipe; 61 /** 62 * @sequence: frame event should be triggered at 63 */ 64 u64 sequence; 65 /** 66 * @event: Actual event which will be sent to userspace. 67 */ 68 union { 69 /** 70 * @event.base: DRM event base class. 71 */ 72 struct drm_event base; 73 74 /** 75 * @event.vbl: 76 * 77 * Event payload for vblank events, requested through 78 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also 79 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace 80 * should use MODE_QUEUE_SEQUENCE and &event.seq instead. 81 */ 82 struct drm_event_vblank vbl; 83 84 /** 85 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL. 86 */ 87 struct drm_event_crtc_sequence seq; 88 } event; 89 }; 90 91 /** 92 * struct drm_vblank_crtc - vblank tracking for a CRTC 93 * 94 * This structure tracks the vblank state for one CRTC. 95 * 96 * Note that for historical reasons - the vblank handling code is still shared 97 * with legacy/non-kms drivers - this is a free-standing structure not directly 98 * connected to &struct drm_crtc. But all public interface functions are taking 99 * a &struct drm_crtc to hide this implementation detail. 100 */ 101 struct drm_vblank_crtc { 102 /** 103 * @dev: Pointer to the &drm_device. 104 */ 105 struct drm_device *dev; 106 /** 107 * @queue: Wait queue for vblank waiters. 108 */ 109 #ifdef __NetBSD__ 110 drm_waitqueue_t queue; 111 #else 112 wait_queue_head_t queue; 113 #endif 114 /** 115 * @disable_timer: Disable timer for the delayed vblank disabling 116 * hysteresis logic. Vblank disabling is controlled through the 117 * drm_vblank_offdelay module option and the setting of the 118 * &drm_device.max_vblank_count value. 119 */ 120 struct timer_list disable_timer; 121 122 /** 123 * @seqlock: Protect vblank count and time. 124 */ 125 seqlock_t seqlock; 126 127 /** 128 * @count: 129 * 130 * Current software vblank counter. 131 * 132 * Note that for a given vblank counter value drm_crtc_handle_vblank() 133 * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() 134 * provide a barrier: Any writes done before calling 135 * drm_crtc_handle_vblank() will be visible to callers of the later 136 * functions, iff the vblank count is the same or a later one. 137 * 138 * IMPORTANT: This guarantee requires barriers, therefor never access 139 * this field directly. Use drm_crtc_vblank_count() instead. 140 */ 141 atomic64_t count; 142 /** 143 * @time: Vblank timestamp corresponding to @count. 144 */ 145 ktime_t time; 146 147 /** 148 * @refcount: Number of users/waiters of the vblank interrupt. Only when 149 * this refcount reaches 0 can the hardware interrupt be disabled using 150 * @disable_timer. 151 */ 152 atomic_t refcount; 153 /** 154 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. 155 */ 156 u32 last; 157 /** 158 * @max_vblank_count: 159 * 160 * Maximum value of the vblank registers for this crtc. This value +1 161 * will result in a wrap-around of the vblank register. It is used 162 * by the vblank core to handle wrap-arounds. 163 * 164 * If set to zero the vblank core will try to guess the elapsed vblanks 165 * between times when the vblank interrupt is disabled through 166 * high-precision timestamps. That approach is suffering from small 167 * races and imprecision over longer time periods, hence exposing a 168 * hardware vblank counter is always recommended. 169 * 170 * This is the runtime configurable per-crtc maximum set through 171 * drm_crtc_set_max_vblank_count(). If this is used the driver 172 * must leave the device wide &drm_device.max_vblank_count at zero. 173 * 174 * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set. 175 */ 176 u32 max_vblank_count; 177 /** 178 * @inmodeset: Tracks whether the vblank is disabled due to a modeset. 179 * For legacy driver bit 2 additionally tracks whether an additional 180 * temporary vblank reference has been acquired to paper over the 181 * hardware counter resetting/jumping. KMS drivers should instead just 182 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly 183 * save and restore the vblank count. 184 */ 185 unsigned int inmodeset; 186 /** 187 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this 188 * structure. 189 */ 190 unsigned int pipe; 191 /** 192 * @framedur_ns: Frame/Field duration in ns, used by 193 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 194 * drm_calc_timestamping_constants(). 195 */ 196 int framedur_ns; 197 /** 198 * @linedur_ns: Line duration in ns, used by 199 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 200 * drm_calc_timestamping_constants(). 201 */ 202 int linedur_ns; 203 204 /** 205 * @hwmode: 206 * 207 * Cache of the current hardware display mode. Only valid when @enabled 208 * is set. This is used by helpers like 209 * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the 210 * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, 211 * because that one is really hard to get from interrupt context. 212 */ 213 struct drm_display_mode hwmode; 214 215 /** 216 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to 217 * avoid double-disabling and hence corrupting saved state. Needed by 218 * drivers not using atomic KMS, since those might go through their CRTC 219 * disabling functions multiple times. 220 */ 221 bool enabled; 222 }; 223 224 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); 225 u64 drm_crtc_vblank_count(struct drm_crtc *crtc); 226 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, 227 ktime_t *vblanktime); 228 void drm_crtc_send_vblank_event(struct drm_crtc *crtc, 229 struct drm_pending_vblank_event *e); 230 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, 231 struct drm_pending_vblank_event *e); 232 void drm_vblank_set_event(struct drm_pending_vblank_event *e, 233 u64 *seq, 234 ktime_t *now); 235 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); 236 bool drm_crtc_handle_vblank(struct drm_crtc *crtc); 237 int drm_crtc_vblank_get(struct drm_crtc *crtc); 238 void drm_crtc_vblank_put(struct drm_crtc *crtc); 239 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe); 240 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); 241 void drm_crtc_vblank_off(struct drm_crtc *crtc); 242 void drm_crtc_vblank_reset(struct drm_crtc *crtc); 243 void drm_crtc_vblank_on(struct drm_crtc *crtc); 244 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); 245 void drm_vblank_restore(struct drm_device *dev, unsigned int pipe); 246 void drm_crtc_vblank_restore(struct drm_crtc *crtc); 247 248 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, 249 unsigned int pipe, int *max_error, 250 ktime_t *vblank_time, 251 bool in_vblank_irq); 252 void drm_calc_timestamping_constants(struct drm_crtc *crtc, 253 const struct drm_display_mode *mode); 254 #ifdef __NetBSD__ 255 drm_waitqueue_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 256 #else 257 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 258 #endif 259 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, 260 u32 max_vblank_count); 261 #endif 262
Indexes created Sun Oct 19 02:09:48 GMT 2025