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 #include <linux/kthread.h> 31 32 #include <drm/drm_file.h> 33 #include <drm/drm_modes.h> 34 35 struct drm_device; 36 struct drm_crtc; 37 struct drm_vblank_work; 38 39 /** 40 * struct drm_pending_vblank_event - pending vblank event tracking 41 */ 42 struct drm_pending_vblank_event { 43 /** 44 * @base: Base structure for tracking pending DRM events. 45 */ 46 struct drm_pending_event base; 47 /** 48 * @pipe: drm_crtc_index() of the &drm_crtc this event is for. 49 */ 50 unsigned int pipe; 51 /** 52 * @sequence: frame event should be triggered at 53 */ 54 u64 sequence; 55 /** 56 * @event: Actual event which will be sent to userspace. 57 */ 58 union { 59 /** 60 * @event.base: DRM event base class. 61 */ 62 struct drm_event base; 63 64 /** 65 * @event.vbl: 66 * 67 * Event payload for vblank events, requested through 68 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also 69 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace 70 * should use MODE_QUEUE_SEQUENCE and &event.seq instead. 71 */ 72 struct drm_event_vblank vbl; 73 74 /** 75 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL. 76 */ 77 struct drm_event_crtc_sequence seq; 78 } event; 79 }; 80 81 /** 82 * struct drm_vblank_crtc_config - vblank configuration for a CRTC 83 */ 84 struct drm_vblank_crtc_config { 85 /** 86 * @offdelay_ms: Vblank off delay in ms, used to determine how long 87 * &drm_vblank_crtc.disable_timer waits before disabling. 88 * 89 * Defaults to the value of drm_vblank_offdelay in drm_crtc_vblank_on(). 90 */ 91 int offdelay_ms; 92 93 /** 94 * @disable_immediate: See &drm_device.vblank_disable_immediate 95 * for the exact semantics of immediate vblank disabling. 96 * 97 * Additionally, this tracks the disable immediate value per crtc, just 98 * in case it needs to differ from the default value for a given device. 99 * 100 * Defaults to the value of &drm_device.vblank_disable_immediate in 101 * drm_crtc_vblank_on(). 102 */ 103 bool disable_immediate; 104 }; 105 106 /** 107 * struct drm_vblank_crtc - vblank tracking for a CRTC 108 * 109 * This structure tracks the vblank state for one CRTC. 110 * 111 * Note that for historical reasons - the vblank handling code is still shared 112 * with legacy/non-kms drivers - this is a free-standing structure not directly 113 * connected to &struct drm_crtc. But all public interface functions are taking 114 * a &struct drm_crtc to hide this implementation detail. 115 */ 116 struct drm_vblank_crtc { 117 /** 118 * @dev: Pointer to the &drm_device. 119 */ 120 struct drm_device *dev; 121 /** 122 * @queue: Wait queue for vblank waiters. 123 */ 124 wait_queue_head_t queue; 125 /** 126 * @disable_timer: Disable timer for the delayed vblank disabling 127 * hysteresis logic. Vblank disabling is controlled through 128 * &drm_vblank_crtc_config.offdelay_ms and the setting of the 129 * &drm_device.max_vblank_count value. 130 */ 131 struct timer_list disable_timer; 132 133 /** 134 * @seqlock: Protect vblank count and time. 135 */ 136 seqlock_t seqlock; 137 138 /** 139 * @count: 140 * 141 * Current software vblank counter. 142 * 143 * Note that for a given vblank counter value drm_crtc_handle_vblank() 144 * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() 145 * provide a barrier: Any writes done before calling 146 * drm_crtc_handle_vblank() will be visible to callers of the later 147 * functions, iff the vblank count is the same or a later one. 148 * 149 * IMPORTANT: This guarantee requires barriers, therefor never access 150 * this field directly. Use drm_crtc_vblank_count() instead. 151 */ 152 atomic64_t count; 153 /** 154 * @time: Vblank timestamp corresponding to @count. 155 */ 156 ktime_t time; 157 158 /** 159 * @refcount: Number of users/waiters of the vblank interrupt. Only when 160 * this refcount reaches 0 can the hardware interrupt be disabled using 161 * @disable_timer. 162 */ 163 atomic_t refcount; 164 /** 165 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. 166 */ 167 u32 last; 168 /** 169 * @max_vblank_count: 170 * 171 * Maximum value of the vblank registers for this crtc. This value +1 172 * will result in a wrap-around of the vblank register. It is used 173 * by the vblank core to handle wrap-arounds. 174 * 175 * If set to zero the vblank core will try to guess the elapsed vblanks 176 * between times when the vblank interrupt is disabled through 177 * high-precision timestamps. That approach is suffering from small 178 * races and imprecision over longer time periods, hence exposing a 179 * hardware vblank counter is always recommended. 180 * 181 * This is the runtime configurable per-crtc maximum set through 182 * drm_crtc_set_max_vblank_count(). If this is used the driver 183 * must leave the device wide &drm_device.max_vblank_count at zero. 184 * 185 * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set. 186 */ 187 u32 max_vblank_count; 188 /** 189 * @inmodeset: Tracks whether the vblank is disabled due to a modeset. 190 * For legacy driver bit 2 additionally tracks whether an additional 191 * temporary vblank reference has been acquired to paper over the 192 * hardware counter resetting/jumping. KMS drivers should instead just 193 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly 194 * save and restore the vblank count. 195 */ 196 unsigned int inmodeset; 197 /** 198 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this 199 * structure. 200 */ 201 unsigned int pipe; 202 /** 203 * @framedur_ns: Frame/Field duration in ns, used by 204 * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by 205 * drm_calc_timestamping_constants(). 206 */ 207 int framedur_ns; 208 /** 209 * @linedur_ns: Line duration in ns, used by 210 * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by 211 * drm_calc_timestamping_constants(). 212 */ 213 int linedur_ns; 214 215 /** 216 * @hwmode: 217 * 218 * Cache of the current hardware display mode. Only valid when @enabled 219 * is set. This is used by helpers like 220 * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access 221 * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, 222 * because that one is really hard to get from interrupt context. 223 */ 224 struct drm_display_mode hwmode; 225 226 /** 227 * @config: Stores vblank configuration values for a given CRTC. 228 * Also, see drm_crtc_vblank_on_config(). 229 */ 230 struct drm_vblank_crtc_config config; 231 232 /** 233 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to 234 * avoid double-disabling and hence corrupting saved state. Needed by 235 * drivers not using atomic KMS, since those might go through their CRTC 236 * disabling functions multiple times. 237 */ 238 bool enabled; 239 240 /** 241 * @worker: The &kthread_worker used for executing vblank works. 242 */ 243 struct kthread_worker *worker; 244 245 /** 246 * @pending_work: A list of scheduled &drm_vblank_work items that are 247 * waiting for a future vblank. 248 */ 249 struct list_head pending_work; 250 251 /** 252 * @work_wait_queue: The wait queue used for signaling that a 253 * &drm_vblank_work item has either finished executing, or was 254 * cancelled. 255 */ 256 wait_queue_head_t work_wait_queue; 257 }; 258 259 struct drm_vblank_crtc *drm_crtc_vblank_crtc(struct drm_crtc *crtc); 260 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); 261 bool drm_dev_has_vblank(const struct drm_device *dev); 262 u64 drm_crtc_vblank_count(struct drm_crtc *crtc); 263 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, 264 ktime_t *vblanktime); 265 int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime); 266 void drm_crtc_send_vblank_event(struct drm_crtc *crtc, 267 struct drm_pending_vblank_event *e); 268 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, 269 struct drm_pending_vblank_event *e); 270 void drm_vblank_set_event(struct drm_pending_vblank_event *e, 271 u64 *seq, 272 ktime_t *now); 273 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); 274 bool drm_crtc_handle_vblank(struct drm_crtc *crtc); 275 int drm_crtc_vblank_get(struct drm_crtc *crtc); 276 void drm_crtc_vblank_put(struct drm_crtc *crtc); 277 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe); 278 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); 279 void drm_crtc_vblank_off(struct drm_crtc *crtc); 280 void drm_crtc_vblank_reset(struct drm_crtc *crtc); 281 void drm_crtc_vblank_on_config(struct drm_crtc *crtc, 282 const struct drm_vblank_crtc_config *config); 283 void drm_crtc_vblank_on(struct drm_crtc *crtc); 284 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); 285 void drm_crtc_vblank_restore(struct drm_crtc *crtc); 286 287 void drm_calc_timestamping_constants(struct drm_crtc *crtc, 288 const struct drm_display_mode *mode); 289 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 290 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, 291 u32 max_vblank_count); 292 293 /* 294 * Helpers for struct drm_crtc_funcs 295 */ 296 297 typedef bool (*drm_vblank_get_scanout_position_func)(struct drm_crtc *crtc, 298 bool in_vblank_irq, 299 int *vpos, int *hpos, 300 ktime_t *stime, 301 ktime_t *etime, 302 const struct drm_display_mode *mode); 303 304 bool 305 drm_crtc_vblank_helper_get_vblank_timestamp_internal(struct drm_crtc *crtc, 306 int *max_error, 307 ktime_t *vblank_time, 308 bool in_vblank_irq, 309 drm_vblank_get_scanout_position_func get_scanout_position); 310 bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, 311 int *max_error, 312 ktime_t *vblank_time, 313 bool in_vblank_irq); 314 315 #endif 316