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
 35struct drm_device;
 36struct drm_crtc;
 37
 38/**
 39 * struct drm_pending_vblank_event - pending vblank event tracking
 40 */
 41struct 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 */
 90struct 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;	/**< VBLANK wait 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;		/* protects vblank count and time */
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;		/* number of users of vblank interruptsper crtc */
127	/**
128	 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling.
129	 */
130	u32 last;
131	/**
132	 * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
133	 * For legacy driver bit 2 additionally tracks whether an additional
134	 * temporary vblank reference has been acquired to paper over the
135	 * hardware counter resetting/jumping. KMS drivers should instead just
136	 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
137	 * save and restore the vblank count.
138	 */
139	unsigned int inmodeset;		/* Display driver is setting mode */
140	/**
141	 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
142	 * structure.
143	 */
144	unsigned int pipe;
145	/**
146	 * @framedur_ns: Frame/Field duration in ns, used by
147	 * drm_calc_vbltimestamp_from_scanoutpos() and computed by
148	 * drm_calc_timestamping_constants().
149	 */
150	int framedur_ns;
151	/**
152	 * @linedur_ns: Line duration in ns, used by
153	 * drm_calc_vbltimestamp_from_scanoutpos() and computed by
154	 * drm_calc_timestamping_constants().
155	 */
156	int linedur_ns;
157
158	/**
159	 * @hwmode:
160	 *
161	 * Cache of the current hardware display mode. Only valid when @enabled
162	 * is set. This is used by helpers like
163	 * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the
164	 * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode,
165	 * because that one is really hard to get from interrupt context.
166	 */
167	struct drm_display_mode hwmode;
168
169	/**
170	 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
171	 * avoid double-disabling and hence corrupting saved state. Needed by
172	 * drivers not using atomic KMS, since those might go through their CRTC
173	 * disabling functions multiple times.
174	 */
175	bool enabled;
176};
177
178int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
179u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
180u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
181				   ktime_t *vblanktime);
182void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
183			       struct drm_pending_vblank_event *e);
184void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
185			      struct drm_pending_vblank_event *e);
186void drm_vblank_set_event(struct drm_pending_vblank_event *e,
187			  u64 *seq,
188			  ktime_t *now);
189bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
190bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
191int drm_crtc_vblank_get(struct drm_crtc *crtc);
192void drm_crtc_vblank_put(struct drm_crtc *crtc);
193void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
194void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
195void drm_crtc_vblank_off(struct drm_crtc *crtc);
196void drm_crtc_vblank_reset(struct drm_crtc *crtc);
197void drm_crtc_vblank_on(struct drm_crtc *crtc);
198u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);
199void drm_vblank_restore(struct drm_device *dev, unsigned int pipe);
200void drm_crtc_vblank_restore(struct drm_crtc *crtc);
201
202bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
203					   unsigned int pipe, int *max_error,
204					   ktime_t *vblank_time,
205					   bool in_vblank_irq);
206void drm_calc_timestamping_constants(struct drm_crtc *crtc,
207				     const struct drm_display_mode *mode);
208wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
209#endif