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1/*2 * Copyright 2016 Intel Corp.3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice (including the next12 * paragraph) shall be included in all copies or substantial portions of the13 * Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL18 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR19 * 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 OR21 * 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 35struct drm_device;36struct drm_crtc;37struct drm_vblank_work;38 39/**40 * struct drm_pending_vblank_event - pending vblank event tracking41 */42struct 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 at53 */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 through68 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also69 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace70 * 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 CRTC83 */84struct drm_vblank_crtc_config {85 /**86 * @offdelay_ms: Vblank off delay in ms, used to determine how long87 * &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_immediate95 * for the exact semantics of immediate vblank disabling.96 *97 * Additionally, this tracks the disable immediate value per crtc, just98 * 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 in101 * drm_crtc_vblank_on().102 */103 bool disable_immediate;104};105 106/**107 * struct drm_vblank_crtc - vblank tracking for a CRTC108 *109 * This structure tracks the vblank state for one CRTC.110 *111 * Note that for historical reasons - the vblank handling code is still shared112 * with legacy/non-kms drivers - this is a free-standing structure not directly113 * connected to &struct drm_crtc. But all public interface functions are taking114 * a &struct drm_crtc to hide this implementation detail.115 */116struct 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 disabling127 * hysteresis logic. Vblank disabling is controlled through128 * &drm_vblank_crtc_config.offdelay_ms and the setting of the129 * &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 calling146 * drm_crtc_handle_vblank() will be visible to callers of the later147 * functions, iff the vblank count is the same or a later one.148 *149 * IMPORTANT: This guarantee requires barriers, therefor never access150 * 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 when160 * this refcount reaches 0 can the hardware interrupt be disabled using161 * @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 +1172 * will result in a wrap-around of the vblank register. It is used173 * by the vblank core to handle wrap-arounds.174 *175 * If set to zero the vblank core will try to guess the elapsed vblanks176 * between times when the vblank interrupt is disabled through177 * high-precision timestamps. That approach is suffering from small178 * races and imprecision over longer time periods, hence exposing a179 * hardware vblank counter is always recommended.180 *181 * This is the runtime configurable per-crtc maximum set through182 * drm_crtc_set_max_vblank_count(). If this is used the driver183 * 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 additional191 * temporary vblank reference has been acquired to paper over the192 * hardware counter resetting/jumping. KMS drivers should instead just193 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly194 * save and restore the vblank count.195 */196 unsigned int inmodeset;197 /**198 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this199 * structure.200 */201 unsigned int pipe;202 /**203 * @framedur_ns: Frame/Field duration in ns, used by204 * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by205 * drm_calc_timestamping_constants().206 */207 int framedur_ns;208 /**209 * @linedur_ns: Line duration in ns, used by210 * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by211 * 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 @enabled219 * is set. This is used by helpers like220 * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access221 * 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 to234 * avoid double-disabling and hence corrupting saved state. Needed by235 * drivers not using atomic KMS, since those might go through their CRTC236 * 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 are247 * 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 a253 * &drm_vblank_work item has either finished executing, or was254 * cancelled.255 */256 wait_queue_head_t work_wait_queue;257};258 259struct drm_vblank_crtc *drm_crtc_vblank_crtc(struct drm_crtc *crtc);260int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);261bool drm_dev_has_vblank(const struct drm_device *dev);262u64 drm_crtc_vblank_count(struct drm_crtc *crtc);263u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,264 ktime_t *vblanktime);265int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime);266void drm_crtc_send_vblank_event(struct drm_crtc *crtc,267 struct drm_pending_vblank_event *e);268void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,269 struct drm_pending_vblank_event *e);270void drm_vblank_set_event(struct drm_pending_vblank_event *e,271 u64 *seq,272 ktime_t *now);273bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);274bool drm_crtc_handle_vblank(struct drm_crtc *crtc);275int drm_crtc_vblank_get(struct drm_crtc *crtc);276void drm_crtc_vblank_put(struct drm_crtc *crtc);277void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);278void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);279void drm_crtc_vblank_off(struct drm_crtc *crtc);280void drm_crtc_vblank_reset(struct drm_crtc *crtc);281void drm_crtc_vblank_on_config(struct drm_crtc *crtc,282 const struct drm_vblank_crtc_config *config);283void drm_crtc_vblank_on(struct drm_crtc *crtc);284u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);285void drm_crtc_vblank_restore(struct drm_crtc *crtc);286 287void drm_calc_timestamping_constants(struct drm_crtc *crtc,288 const struct drm_display_mode *mode);289wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);290void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc,291 u32 max_vblank_count);292 293/*294 * Helpers for struct drm_crtc_funcs295 */296 297typedef 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 304bool305drm_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);310bool 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#endif316