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; 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 }; 197 198 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); 199 u64 drm_crtc_vblank_count(struct drm_crtc *crtc); 200 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, 201 ktime_t *vblanktime); 202 void drm_crtc_send_vblank_event(struct drm_crtc *crtc, 203 struct drm_pending_vblank_event *e); 204 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, 205 struct drm_pending_vblank_event *e); 206 void drm_vblank_set_event(struct drm_pending_vblank_event *e, 207 u64 *seq, 208 ktime_t *now); 209 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); 210 bool drm_crtc_handle_vblank(struct drm_crtc *crtc); 211 int drm_crtc_vblank_get(struct drm_crtc *crtc); 212 void drm_crtc_vblank_put(struct drm_crtc *crtc); 213 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe); 214 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); 215 void drm_crtc_vblank_off(struct drm_crtc *crtc); 216 void drm_crtc_vblank_reset(struct drm_crtc *crtc); 217 void drm_crtc_vblank_on(struct drm_crtc *crtc); 218 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); 219 void drm_vblank_restore(struct drm_device *dev, unsigned int pipe); 220 void drm_crtc_vblank_restore(struct drm_crtc *crtc); 221 222 bool 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); 226 void drm_calc_timestamping_constants(struct drm_crtc *crtc, 227 const struct drm_display_mode *mode); 228 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 229 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, 230 u32 max_vblank_count); 231 #endif 232