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Diffstat (limited to 'include/drm/drm_vblank.h')
| -rw-r--r-- | include/drm/drm_vblank.h | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h new file mode 100644 index 0000000000..7f3957943d --- /dev/null +++ b/include/drm/drm_vblank.h @@ -0,0 +1,281 @@ +/* + * Copyright 2016 Intel Corp. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef _DRM_VBLANK_H_ +#define _DRM_VBLANK_H_ + +#include <linux/seqlock.h> +#include <linux/idr.h> +#include <linux/poll.h> +#include <linux/kthread.h> + +#include <drm/drm_file.h> +#include <drm/drm_modes.h> + +struct drm_device; +struct drm_crtc; +struct drm_vblank_work; + +/** + * struct drm_pending_vblank_event - pending vblank event tracking + */ +struct drm_pending_vblank_event { + /** + * @base: Base structure for tracking pending DRM events. + */ + struct drm_pending_event base; + /** + * @pipe: drm_crtc_index() of the &drm_crtc this event is for. + */ + unsigned int pipe; + /** + * @sequence: frame event should be triggered at + */ + u64 sequence; + /** + * @event: Actual event which will be sent to userspace. + */ + union { + /** + * @event.base: DRM event base class. + */ + struct drm_event base; + + /** + * @event.vbl: + * + * Event payload for vblank events, requested through + * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also + * generated by the legacy WAIT_VBLANK IOCTL, but new userspace + * should use MODE_QUEUE_SEQUENCE and &event.seq instead. + */ + struct drm_event_vblank vbl; + + /** + * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL. + */ + struct drm_event_crtc_sequence seq; + } event; +}; + +/** + * struct drm_vblank_crtc - vblank tracking for a CRTC + * + * This structure tracks the vblank state for one CRTC. + * + * Note that for historical reasons - the vblank handling code is still shared + * with legacy/non-kms drivers - this is a free-standing structure not directly + * connected to &struct drm_crtc. But all public interface functions are taking + * a &struct drm_crtc to hide this implementation detail. + */ +struct drm_vblank_crtc { + /** + * @dev: Pointer to the &drm_device. + */ + struct drm_device *dev; + /** + * @queue: Wait queue for vblank waiters. + */ + wait_queue_head_t queue; + /** + * @disable_timer: Disable timer for the delayed vblank disabling + * hysteresis logic. Vblank disabling is controlled through the + * drm_vblank_offdelay module option and the setting of the + * &drm_device.max_vblank_count value. + */ + struct timer_list disable_timer; + + /** + * @seqlock: Protect vblank count and time. + */ + seqlock_t seqlock; + + /** + * @count: + * + * Current software vblank counter. + * + * Note that for a given vblank counter value drm_crtc_handle_vblank() + * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time() + * provide a barrier: Any writes done before calling + * drm_crtc_handle_vblank() will be visible to callers of the later + * functions, iff the vblank count is the same or a later one. + * + * IMPORTANT: This guarantee requires barriers, therefor never access + * this field directly. Use drm_crtc_vblank_count() instead. + */ + atomic64_t count; + /** + * @time: Vblank timestamp corresponding to @count. + */ + ktime_t time; + + /** + * @refcount: Number of users/waiters of the vblank interrupt. Only when + * this refcount reaches 0 can the hardware interrupt be disabled using + * @disable_timer. + */ + atomic_t refcount; + /** + * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. + */ + u32 last; + /** + * @max_vblank_count: + * + * Maximum value of the vblank registers for this crtc. This value +1 + * will result in a wrap-around of the vblank register. It is used + * by the vblank core to handle wrap-arounds. + * + * If set to zero the vblank core will try to guess the elapsed vblanks + * between times when the vblank interrupt is disabled through + * high-precision timestamps. That approach is suffering from small + * races and imprecision over longer time periods, hence exposing a + * hardware vblank counter is always recommended. + * + * This is the runtime configurable per-crtc maximum set through + * drm_crtc_set_max_vblank_count(). If this is used the driver + * must leave the device wide &drm_device.max_vblank_count at zero. + * + * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set. + */ + u32 max_vblank_count; + /** + * @inmodeset: Tracks whether the vblank is disabled due to a modeset. + * For legacy driver bit 2 additionally tracks whether an additional + * temporary vblank reference has been acquired to paper over the + * hardware counter resetting/jumping. KMS drivers should instead just + * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly + * save and restore the vblank count. + */ + unsigned int inmodeset; + /** + * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this + * structure. + */ + unsigned int pipe; + /** + * @framedur_ns: Frame/Field duration in ns, used by + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by + * drm_calc_timestamping_constants(). + */ + int framedur_ns; + /** + * @linedur_ns: Line duration in ns, used by + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by + * drm_calc_timestamping_constants(). + */ + int linedur_ns; + + /** + * @hwmode: + * + * Cache of the current hardware display mode. Only valid when @enabled + * is set. This is used by helpers like + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, + * because that one is really hard to get from interrupt context. + */ + struct drm_display_mode hwmode; + + /** + * @enabled: Tracks the enabling state of the corresponding &drm_crtc to + * avoid double-disabling and hence corrupting saved state. Needed by + * drivers not using atomic KMS, since those might go through their CRTC + * disabling functions multiple times. + */ + bool enabled; + + /** + * @worker: The &kthread_worker used for executing vblank works. + */ + struct kthread_worker *worker; + + /** + * @pending_work: A list of scheduled &drm_vblank_work items that are + * waiting for a future vblank. + */ + struct list_head pending_work; + + /** + * @work_wait_queue: The wait queue used for signaling that a + * &drm_vblank_work item has either finished executing, or was + * cancelled. + */ + wait_queue_head_t work_wait_queue; +}; + +int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); +bool drm_dev_has_vblank(const struct drm_device *dev); +u64 drm_crtc_vblank_count(struct drm_crtc *crtc); +u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, + ktime_t *vblanktime); +int drm_crtc_next_vblank_start(struct drm_crtc *crtc, ktime_t *vblanktime); +void drm_crtc_send_vblank_event(struct drm_crtc *crtc, + struct drm_pending_vblank_event *e); +void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, + struct drm_pending_vblank_event *e); +void drm_vblank_set_event(struct drm_pending_vblank_event *e, + u64 *seq, + ktime_t *now); +bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); +bool drm_crtc_handle_vblank(struct drm_crtc *crtc); +int drm_crtc_vblank_get(struct drm_crtc *crtc); +void drm_crtc_vblank_put(struct drm_crtc *crtc); +void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe); +void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); +void drm_crtc_vblank_off(struct drm_crtc *crtc); +void drm_crtc_vblank_reset(struct drm_crtc *crtc); +void drm_crtc_vblank_on(struct drm_crtc *crtc); +u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); +void drm_crtc_vblank_restore(struct drm_crtc *crtc); + +void drm_calc_timestamping_constants(struct drm_crtc *crtc, + const struct drm_display_mode *mode); +wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); +void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, + u32 max_vblank_count); + +/* + * Helpers for struct drm_crtc_funcs + */ + +typedef bool (*drm_vblank_get_scanout_position_func)(struct drm_crtc *crtc, + bool in_vblank_irq, + int *vpos, int *hpos, + ktime_t *stime, + ktime_t *etime, + const struct drm_display_mode *mode); + +bool +drm_crtc_vblank_helper_get_vblank_timestamp_internal(struct drm_crtc *crtc, + int *max_error, + ktime_t *vblank_time, + bool in_vblank_irq, + drm_vblank_get_scanout_position_func get_scanout_position); +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, + int *max_error, + ktime_t *vblank_time, + bool in_vblank_irq); + +#endif |