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
34 struct drm_device;
35 struct drm_crtc;
36
37 /**
38 * struct drm_pending_vblank_event - pending vblank event tracking
39 */
40 struct 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 */
89 struct 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
197 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
198 u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
199 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
200 ktime_t *vblanktime);
201 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
202 struct drm_pending_vblank_event *e);
203 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
204 struct drm_pending_vblank_event *e);
205 void drm_vblank_set_event(struct drm_pending_vblank_event *e,
206 u64 *seq,
207 ktime_t *now);
208 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
209 bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
210 int drm_crtc_vblank_get(struct drm_crtc *crtc);
211 void drm_crtc_vblank_put(struct drm_crtc *crtc);
212 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
213 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
214 void drm_crtc_vblank_off(struct drm_crtc *crtc);
215 void drm_crtc_vblank_reset(struct drm_crtc *crtc);
216 void drm_crtc_vblank_on(struct drm_crtc *crtc);
217 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc);
218 void drm_vblank_restore(struct drm_device *dev, unsigned int pipe);
219 void drm_crtc_vblank_restore(struct drm_crtc *crtc);
220
221 bool 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);
225 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
226 const struct drm_display_mode *mode);
227 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc);
228 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc,
229 u32 max_vblank_count);
230 #endif