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
 34struct drm_device;
 35struct drm_crtc;
 36
 37/**
 38 * struct drm_pending_vblank_event - pending vblank event tracking
 39 */
 40struct drm_pending_vblank_event {
 41	/**
 42	 * @base: Base structure for tracking pending DRM events.
 43	 */
 44	struct drm_pending_event base;
 45	/**
 46	 * @pipe: drm_crtc_index() of the &drm_crtc this event is for.
 47	 */
 48	unsigned int pipe;
 49	/**
 50	 * @sequence: frame event should be triggered at
 51	 */
 52	u64 sequence;
 53	/**
 54	 * @event: Actual event which will be sent to userspace.
 55	 */
 56	union {
 57		/**
 58		 * @event.base: DRM event base class.
 59		 */
 60		struct drm_event base;
 61
 62		/**
 63		 * @event.vbl:
 64		 *
 65		 * Event payload for vblank events, requested through
 66		 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also
 67		 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace
 68		 * should use MODE_QUEUE_SEQUENCE and &event.seq instead.
 69		 */
 70		struct drm_event_vblank vbl;
 71
 72		/**
 73		 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL.
 74		 */
 75		struct drm_event_crtc_sequence seq;
 76	} event;
 77};
 78
 79/**
 80 * struct drm_vblank_crtc - vblank tracking for a CRTC
 81 *
 82 * This structure tracks the vblank state for one CRTC.
 83 *
 84 * Note that for historical reasons - the vblank handling code is still shared
 85 * with legacy/non-kms drivers - this is a free-standing structure not directly
 86 * connected to &struct drm_crtc. But all public interface functions are taking
 87 * a &struct drm_crtc to hide this implementation detail.
 88 */
 89struct drm_vblank_crtc {
 90	/**
 91	 * @dev: Pointer to the &drm_device.
 92	 */
 93	struct drm_device *dev;
 94	/**
 95	 * @queue: Wait queue for vblank waiters.
 96	 */
 97	wait_queue_head_t queue;
 98	/**
 99	 * @disable_timer: Disable timer for the delayed vblank disabling
100	 * hysteresis logic. Vblank disabling is controlled through the
101	 * drm_vblank_offdelay module option and the setting of the
102	 * &drm_device.max_vblank_count value.
103	 */
104	struct timer_list disable_timer;
105
106	/**
107	 * @seqlock: Protect vblank count and time.
108	 */
109	seqlock_t seqlock;
110
111	/**
112	 * @count: Current software vblank counter.
113	 */
114	u64 count;
115	/**
116	 * @time: Vblank timestamp corresponding to @count.
117	 */
118	ktime_t time;
119
120	/**
121	 * @refcount: Number of users/waiters of the vblank interrupt. Only when
122	 * this refcount reaches 0 can the hardware interrupt be disabled using
123	 * @disable_timer.
124	 */
125	atomic_t refcount;
126	/**
127	 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling.
128	 */
129	u32 last;
130	/**
131	 * @max_vblank_count:
132	 *
133	 * Maximum value of the vblank registers for this crtc. This value +1
134	 * will result in a wrap-around of the vblank register. It is used
135	 * by the vblank core to handle wrap-arounds.
136	 *
137	 * If set to zero the vblank core will try to guess the elapsed vblanks
138	 * between times when the vblank interrupt is disabled through
139	 * high-precision timestamps. That approach is suffering from small
140	 * races and imprecision over longer time periods, hence exposing a
141	 * hardware vblank counter is always recommended.
142	 *
143	 * This is the runtime configurable per-crtc maximum set through
144	 * drm_crtc_set_max_vblank_count(). If this is used the driver
145	 * must leave the device wide &drm_device.max_vblank_count at zero.
146	 *
147	 * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set.
148	 */
149	u32 max_vblank_count;
150	/**
151	 * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
152	 * For legacy driver bit 2 additionally tracks whether an additional
153	 * temporary vblank reference has been acquired to paper over the
154	 * hardware counter resetting/jumping. KMS drivers should instead just
155	 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
156	 * save and restore the vblank count.
157	 */
158	unsigned int inmodeset;
159	/**
160	 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
161	 * structure.
162	 */
163	unsigned int pipe;
164	/**
165	 * @framedur_ns: Frame/Field duration in ns, used by
166	 * drm_calc_vbltimestamp_from_scanoutpos() and computed by
167	 * drm_calc_timestamping_constants().
168	 */
169	int framedur_ns;
170	/**
171	 * @linedur_ns: Line duration in ns, used by
172	 * drm_calc_vbltimestamp_from_scanoutpos() and computed by
173	 * drm_calc_timestamping_constants().
174	 */
175	int linedur_ns;
176
177	/**
178	 * @hwmode:
179	 *
180	 * Cache of the current hardware display mode. Only valid when @enabled
181	 * is set. This is used by helpers like
182	 * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the
183	 * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode,
184	 * because that one is really hard to get from interrupt context.
185	 */
186	struct drm_display_mode hwmode;
187
188	/**
189	 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
190	 * avoid double-disabling and hence corrupting saved state. Needed by
191	 * drivers not using atomic KMS, since those might go through their CRTC
192	 * disabling functions multiple times.
193	 */
194	bool enabled;
195};
196
197int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
198u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
199u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
200				   ktime_t *vblanktime);
201void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
202			       struct drm_pending_vblank_event *e);
203void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
204			      struct drm_pending_vblank_event *e);
205void drm_vblank_set_event(struct drm_pending_vblank_event *e,
206			  u64 *seq,
207			  ktime_t *now);
208bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
209bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
210int drm_crtc_vblank_get(struct drm_crtc *crtc);
211void drm_crtc_vblank_put(struct drm_crtc *crtc);
212void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
213void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
214void drm_crtc_vblank_off(struct drm_crtc *crtc);
215void drm_crtc_vblank_reset(struct drm_crtc *crtc);
216void drm_crtc_vblank_on(struct drm_crtc *crtc);
217u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);
218void drm_vblank_restore(struct drm_device *dev, unsigned int pipe);
219void drm_crtc_vblank_restore(struct drm_crtc *crtc);
220
221bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
222					   unsigned int pipe, int *max_error,
223					   ktime_t *vblank_time,
224					   bool in_vblank_irq);
225void drm_calc_timestamping_constants(struct drm_crtc *crtc,
226				     const struct drm_display_mode *mode);
227wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
228void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc,
229				   u32 max_vblank_count);
230#endif