1 /* $NetBSD: drm_vblank.h,v 1.12 2021/12/20 12:56:07 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 #ifdef __NetBSD__ 30 #include <sys/types.h> 31 #include <sys/file.h> 32 #define pipe pipe_drmhack /* see intel_display.h */ 33 #endif 34 35 #include <linux/seqlock.h> 36 #include <linux/idr.h> 37 #include <linux/poll.h> 38 #include <linux/timer.h> 39 #include <linux/ktime.h> 40 41 #include <drm/drm_file.h> 42 #include <drm/drm_modes.h> 43 44 #ifdef __NetBSD__ /* XXX */ 45 #include <drm/drm_wait_netbsd.h> 46 #endif 47 48 struct drm_device; 49 struct drm_crtc; 50 51 /** 52 * struct drm_pending_vblank_event - pending vblank event tracking 53 */ 54 struct drm_pending_vblank_event { 55 /** 56 * @base: Base structure for tracking pending DRM events. 57 */ 58 struct drm_pending_event base; 59 /** 60 * @pipe: drm_crtc_index() of the &drm_crtc this event is for. 61 */ 62 unsigned int pipe; 63 /** 64 * @sequence: frame event should be triggered at 65 */ 66 u64 sequence; 67 /** 68 * @event: Actual event which will be sent to userspace. 69 */ 70 union { 71 /** 72 * @event.base: DRM event base class. 73 */ 74 struct drm_event base; 75 76 /** 77 * @event.vbl: 78 * 79 * Event payload for vblank events, requested through 80 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also 81 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace 82 * should use MODE_QUEUE_SEQUENCE and &event.seq instead. 83 */ 84 struct drm_event_vblank vbl; 85 86 /** 87 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL. 88 */ 89 struct drm_event_crtc_sequence seq; 90 } event; 91 }; 92 93 /** 94 * struct drm_vblank_crtc - vblank tracking for a CRTC 95 * 96 * This structure tracks the vblank state for one CRTC. 97 * 98 * Note that for historical reasons - the vblank handling code is still shared 99 * with legacy/non-kms drivers - this is a free-standing structure not directly 100 * connected to &struct drm_crtc. But all public interface functions are taking 101 * a &struct drm_crtc to hide this implementation detail. 102 */ 103 struct drm_vblank_crtc { 104 /** 105 * @dev: Pointer to the &drm_device. 106 */ 107 struct drm_device *dev; 108 /** 109 * @queue: Wait queue for vblank waiters. 110 */ 111 drm_waitqueue_t queue; 112 /** 113 * @disable_timer: Disable timer for the delayed vblank disabling 114 * hysteresis logic. Vblank disabling is controlled through the 115 * drm_vblank_offdelay module option and the setting of the 116 * &drm_device.max_vblank_count value. 117 */ 118 struct timer_list disable_timer; 119 120 /** 121 * @seqlock: Protect vblank count and time. 122 */ 123 seqlock_t seqlock; 124 125 /** 126 * @count: 127 * 128 * Current software vblank counter. 129 * 130 * Note that for a given vblank counter value drm_crtc_handle_vblank() 131 * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() 132 * provide a barrier: Any writes done before calling 133 * drm_crtc_handle_vblank() will be visible to callers of the later 134 * functions, iff the vblank count is the same or a later one. 135 * 136 * IMPORTANT: This guarantee requires barriers, therefor never access 137 * this field directly. Use drm_crtc_vblank_count() instead. 138 */ 139 atomic64_t count; 140 /** 141 * @time: Vblank timestamp corresponding to @count. 142 */ 143 ktime_t time; 144 145 /** 146 * @refcount: Number of users/waiters of the vblank interrupt. Only when 147 * this refcount reaches 0 can the hardware interrupt be disabled using 148 * @disable_timer. 149 */ 150 atomic_t refcount; 151 /** 152 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. 153 */ 154 u32 last; 155 /** 156 * @max_vblank_count: 157 * 158 * Maximum value of the vblank registers for this crtc. This value +1 159 * will result in a wrap-around of the vblank register. It is used 160 * by the vblank core to handle wrap-arounds. 161 * 162 * If set to zero the vblank core will try to guess the elapsed vblanks 163 * between times when the vblank interrupt is disabled through 164 * high-precision timestamps. That approach is suffering from small 165 * races and imprecision over longer time periods, hence exposing a 166 * hardware vblank counter is always recommended. 167 * 168 * This is the runtime configurable per-crtc maximum set through 169 * drm_crtc_set_max_vblank_count(). If this is used the driver 170 * must leave the device wide &drm_device.max_vblank_count at zero. 171 * 172 * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set. 173 */ 174 u32 max_vblank_count; 175 /** 176 * @inmodeset: Tracks whether the vblank is disabled due to a modeset. 177 * For legacy driver bit 2 additionally tracks whether an additional 178 * temporary vblank reference has been acquired to paper over the 179 * hardware counter resetting/jumping. KMS drivers should instead just 180 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly 181 * save and restore the vblank count. 182 */ 183 unsigned int inmodeset; 184 /** 185 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this 186 * structure. 187 */ 188 unsigned int pipe; 189 /** 190 * @framedur_ns: Frame/Field duration in ns, used by 191 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 192 * drm_calc_timestamping_constants(). 193 */ 194 int framedur_ns; 195 /** 196 * @linedur_ns: Line duration in ns, used by 197 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 198 * drm_calc_timestamping_constants(). 199 */ 200 int linedur_ns; 201 202 /** 203 * @hwmode: 204 * 205 * Cache of the current hardware display mode. Only valid when @enabled 206 * is set. This is used by helpers like 207 * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the 208 * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, 209 * because that one is really hard to get from interrupt context. 210 */ 211 struct drm_display_mode hwmode; 212 213 /** 214 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to 215 * avoid double-disabling and hence corrupting saved state. Needed by 216 * drivers not using atomic KMS, since those might go through their CRTC 217 * disabling functions multiple times. 218 */ 219 bool enabled; 220 }; 221 222 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); 223 u64 drm_crtc_vblank_count(struct drm_crtc *crtc); 224 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, 225 ktime_t *vblanktime); 226 void drm_crtc_send_vblank_event(struct drm_crtc *crtc, 227 struct drm_pending_vblank_event *e); 228 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, 229 struct drm_pending_vblank_event *e); 230 void drm_vblank_set_event(struct drm_pending_vblank_event *e, 231 u64 *seq, 232 ktime_t *now); 233 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); 234 bool drm_crtc_handle_vblank(struct drm_crtc *crtc); 235 int drm_crtc_vblank_get(struct drm_crtc *crtc); 236 int drm_crtc_vblank_get_locked(struct drm_crtc *crtc); 237 void drm_crtc_vblank_put(struct drm_crtc *crtc); 238 void drm_crtc_vblank_put_locked(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 drm_waitqueue_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 255 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, 256 u32 max_vblank_count); 257 #endif 258