1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H
18 #define ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H
19 
20 #include <stdint.h>
21 #include <sys/cdefs.h>
22 
23 #include <hardware/gralloc.h>
24 #include <hardware/hardware.h>
25 #include <cutils/native_handle.h>
26 
27 #include <hardware/hwcomposer_defs.h>
28 
29 __BEGIN_DECLS
30 
31 /*****************************************************************************/
32 
33 /* for compatibility */
34 #define HWC_MODULE_API_VERSION      HWC_MODULE_API_VERSION_0_1
35 #define HWC_DEVICE_API_VERSION      HWC_DEVICE_API_VERSION_0_1
36 #define HWC_API_VERSION             HWC_DEVICE_API_VERSION
37 
38 /*****************************************************************************/
39 
40 typedef struct hwc_layer_1 {
41     /*
42      * compositionType is used to specify this layer's type and is set by either
43      * the hardware composer implementation, or by the caller (see below).
44      *
45      *  This field is always reset to HWC_BACKGROUND or HWC_FRAMEBUFFER
46      *  before (*prepare)() is called when the HWC_GEOMETRY_CHANGED flag is
47      *  also set, otherwise, this field is preserved between (*prepare)()
48      *  calls.
49      *
50      * HWC_BACKGROUND
51      *   Always set by the caller before calling (*prepare)(), this value
52      *   indicates this is a special "background" layer. The only valid field
53      *   is backgroundColor.
54      *   The HWC can toggle this value to HWC_FRAMEBUFFER to indicate it CANNOT
55      *   handle the background color.
56      *
57      *
58      * HWC_FRAMEBUFFER_TARGET
59      *   Always set by the caller before calling (*prepare)(), this value
60      *   indicates this layer is the framebuffer surface used as the target of
61      *   OpenGL ES composition. If the HWC sets all other layers to HWC_OVERLAY
62      *   or HWC_BACKGROUND, then no OpenGL ES composition will be done, and
63      *   this layer should be ignored during set().
64      *
65      *   This flag (and the framebuffer surface layer) will only be used if the
66      *   HWC version is HWC_DEVICE_API_VERSION_1_1 or higher. In older versions,
67      *   the OpenGL ES target surface is communicated by the (dpy, sur) fields
68      *   in hwc_compositor_device_1_t.
69      *
70      *   This value cannot be set by the HWC implementation.
71      *
72      *
73      * HWC_FRAMEBUFFER
74      *   Set by the caller before calling (*prepare)() ONLY when the
75      *   HWC_GEOMETRY_CHANGED flag is also set.
76      *
77      *   Set by the HWC implementation during (*prepare)(), this indicates
78      *   that the layer will be drawn into the framebuffer using OpenGL ES.
79      *   The HWC can toggle this value to HWC_OVERLAY to indicate it will
80      *   handle the layer.
81      *
82      *
83      * HWC_OVERLAY
84      *   Set by the HWC implementation during (*prepare)(), this indicates
85      *   that the layer will be handled by the HWC (ie: it must not be
86      *   composited with OpenGL ES).
87      *
88      *
89      * HWC_SIDEBAND
90      *   Set by the caller before calling (*prepare)(), this value indicates
91      *   the contents of this layer come from a sideband video stream.
92      *
93      *   The h/w composer is responsible for receiving new image buffers from
94      *   the stream at the appropriate time (e.g. synchronized to a separate
95      *   audio stream), compositing them with the current contents of other
96      *   layers, and displaying the resulting image. This happens
97      *   independently of the normal prepare/set cycle. The prepare/set calls
98      *   only happen when other layers change, or when properties of the
99      *   sideband layer such as position or size change.
100      *
101      *   If the h/w composer can't handle the layer as a sideband stream for
102      *   some reason (e.g. unsupported scaling/blending/rotation, or too many
103      *   sideband layers) it can set compositionType to HWC_FRAMEBUFFER in
104      *   (*prepare)(). However, doing so will result in the layer being shown
105      *   as a solid color since the platform is not currently able to composite
106      *   sideband layers with the GPU. This may be improved in future
107      *   versions of the platform.
108      *
109      *
110      * HWC_CURSOR_OVERLAY
111      *   Set by the HWC implementation during (*prepare)(), this value
112      *   indicates the layer's composition will now be handled by the HWC.
113      *   Additionally, the client can now asynchronously update the on-screen
114      *   position of this layer using the setCursorPositionAsync() api.
115      */
116     int32_t compositionType;
117 
118     /*
119      * hints is bit mask set by the HWC implementation during (*prepare)().
120      * It is preserved between (*prepare)() calls, unless the
121      * HWC_GEOMETRY_CHANGED flag is set, in which case it is reset to 0.
122      *
123      * see hwc_layer_t::hints
124      */
125     uint32_t hints;
126 
127     /* see hwc_layer_t::flags */
128     uint32_t flags;
129 
130     union {
131         /* color of the background.  hwc_color_t.a is ignored */
132         hwc_color_t backgroundColor;
133 
134         struct {
135             union {
136                 /* When compositionType is HWC_FRAMEBUFFER, HWC_OVERLAY,
137                  * HWC_FRAMEBUFFER_TARGET, this is the handle of the buffer to
138                  * compose. This handle is guaranteed to have been allocated
139                  * from gralloc using the GRALLOC_USAGE_HW_COMPOSER usage flag.
140                  * If the layer's handle is unchanged across two consecutive
141                  * prepare calls and the HWC_GEOMETRY_CHANGED flag is not set
142                  * for the second call then the HWComposer implementation may
143                  * assume that the contents of the buffer have not changed. */
144                 buffer_handle_t handle;
145 
146                 /* When compositionType is HWC_SIDEBAND, this is the handle
147                  * of the sideband video stream to compose. */
148                 const native_handle_t* sidebandStream;
149             };
150 
151             /* transformation to apply to the buffer during composition */
152             uint32_t transform;
153 
154             /* blending to apply during composition */
155             int32_t blending;
156 
157             /* area of the source to consider, the origin is the top-left corner of
158              * the buffer. As of HWC_DEVICE_API_VERSION_1_3, sourceRect uses floats.
159              * If the h/w can't support a non-integer source crop rectangle, it should
160              * punt to OpenGL ES composition.
161              */
162             union {
163                 // crop rectangle in integer (pre HWC_DEVICE_API_VERSION_1_3)
164                 hwc_rect_t sourceCropi;
165                 hwc_rect_t sourceCrop; // just for source compatibility
166                 // crop rectangle in floats (as of HWC_DEVICE_API_VERSION_1_3)
167                 hwc_frect_t sourceCropf;
168             };
169 
170             /* where to composite the sourceCrop onto the display. The sourceCrop
171              * is scaled using linear filtering to the displayFrame. The origin is the
172              * top-left corner of the screen.
173              */
174             hwc_rect_t displayFrame;
175 
176             /* visible region in screen space. The origin is the
177              * top-left corner of the screen.
178              * The visible region INCLUDES areas overlapped by a translucent layer.
179              */
180             hwc_region_t visibleRegionScreen;
181 
182             /* Sync fence object that will be signaled when the buffer's
183              * contents are available. May be -1 if the contents are already
184              * available. This field is only valid during set(), and should be
185              * ignored during prepare(). The set() call must not wait for the
186              * fence to be signaled before returning, but the HWC must wait for
187              * all buffers to be signaled before reading from them.
188              *
189              * HWC_FRAMEBUFFER layers will never have an acquire fence, since
190              * reads from them are complete before the framebuffer is ready for
191              * display.
192              *
193              * HWC_SIDEBAND layers will never have an acquire fence, since
194              * synchronization is handled through implementation-defined
195              * sideband mechanisms.
196              *
197              * The HWC takes ownership of the acquireFenceFd and is responsible
198              * for closing it when no longer needed.
199              */
200             int acquireFenceFd;
201 
202             /* During set() the HWC must set this field to a file descriptor for
203              * a sync fence object that will signal after the HWC has finished
204              * reading from the buffer. The field is ignored by prepare(). Each
205              * layer should have a unique file descriptor, even if more than one
206              * refer to the same underlying fence object; this allows each to be
207              * closed independently.
208              *
209              * If buffer reads can complete at significantly different times,
210              * then using independent fences is preferred. For example, if the
211              * HWC handles some layers with a blit engine and others with
212              * overlays, then the blit layers can be reused immediately after
213              * the blit completes, but the overlay layers can't be reused until
214              * a subsequent frame has been displayed.
215              *
216              * Since HWC doesn't read from HWC_FRAMEBUFFER layers, it shouldn't
217              * produce a release fence for them. The releaseFenceFd will be -1
218              * for these layers when set() is called.
219              *
220              * Since HWC_SIDEBAND buffers don't pass through the HWC client,
221              * the HWC shouldn't produce a release fence for them. The
222              * releaseFenceFd will be -1 for these layers when set() is called.
223              *
224              * The HWC client taks ownership of the releaseFenceFd and is
225              * responsible for closing it when no longer needed.
226              */
227             int releaseFenceFd;
228 
229             /*
230              * Availability: HWC_DEVICE_API_VERSION_1_2
231              *
232              * Alpha value applied to the whole layer. The effective
233              * value of each pixel is computed as:
234              *
235              *   if (blending == HWC_BLENDING_PREMULT)
236              *      pixel.rgb = pixel.rgb * planeAlpha / 255
237              *   pixel.a = pixel.a * planeAlpha / 255
238              *
239              * Then blending proceeds as usual according to the "blending"
240              * field above.
241              *
242              * NOTE: planeAlpha applies to YUV layers as well:
243              *
244              *   pixel.rgb = yuv_to_rgb(pixel.yuv)
245              *   if (blending == HWC_BLENDING_PREMULT)
246              *      pixel.rgb = pixel.rgb * planeAlpha / 255
247              *   pixel.a = planeAlpha
248              *
249              *
250              * IMPLEMENTATION NOTE:
251              *
252              * If the source image doesn't have an alpha channel, then
253              * the h/w can use the HWC_BLENDING_COVERAGE equations instead of
254              * HWC_BLENDING_PREMULT and simply set the alpha channel to
255              * planeAlpha.
256              *
257              * e.g.:
258              *
259              *   if (blending == HWC_BLENDING_PREMULT)
260              *      blending = HWC_BLENDING_COVERAGE;
261              *   pixel.a = planeAlpha;
262              *
263              */
264             uint8_t planeAlpha;
265 
266             /* Pad to 32 bits */
267             uint8_t _pad[3];
268 
269             /*
270              * Availability: HWC_DEVICE_API_VERSION_1_5
271              *
272              * This defines the region of the source buffer that has been
273              * modified since the last frame.
274              *
275              * If surfaceDamage.numRects > 0, then it may be assumed that any
276              * portion of the source buffer not covered by one of the rects has
277              * not been modified this frame. If surfaceDamage.numRects == 0,
278              * then the whole source buffer must be treated as if it had been
279              * modified.
280              *
281              * If the layer's contents are not modified relative to the prior
282              * prepare/set cycle, surfaceDamage will contain exactly one empty
283              * rect ([0, 0, 0, 0]).
284              *
285              * The damage rects are relative to the pre-transformed buffer, and
286              * their origin is the top-left corner.
287              */
288             hwc_region_t surfaceDamage;
289         };
290     };
291 
292 #ifdef __LP64__
293     /*
294      * For 64-bit mode, this struct is 120 bytes (and 8-byte aligned), and needs
295      * to be padded as such to maintain binary compatibility.
296      */
297     uint8_t reserved[120 - 112];
298 #else
299     /*
300      * For 32-bit mode, this struct is 96 bytes, and needs to be padded as such
301      * to maintain binary compatibility.
302      */
303     uint8_t reserved[96 - 84];
304 #endif
305 
306 } hwc_layer_1_t;
307 
308 /* This represents a display, typically an EGLDisplay object */
309 typedef void* hwc_display_t;
310 
311 /* This represents a surface, typically an EGLSurface object  */
312 typedef void* hwc_surface_t;
313 
314 /*
315  * hwc_display_contents_1_t::flags values
316  */
317 enum {
318     /*
319      * HWC_GEOMETRY_CHANGED is set by SurfaceFlinger to indicate that the list
320      * passed to (*prepare)() has changed by more than just the buffer handles
321      * and acquire fences.
322      */
323     HWC_GEOMETRY_CHANGED = 0x00000001,
324 };
325 
326 /*
327  * Description of the contents to output on a display.
328  *
329  * This is the top-level structure passed to the prepare and set calls to
330  * negotiate and commit the composition of a display image.
331  */
332 typedef struct hwc_display_contents_1 {
333     /* File descriptor referring to a Sync HAL fence object which will signal
334      * when this composition is retired. For a physical display, a composition
335      * is retired when it has been replaced on-screen by a subsequent set. For
336      * a virtual display, the composition is retired when the writes to
337      * outputBuffer are complete and can be read. The fence object is created
338      * and returned by the set call; this field will be -1 on entry to prepare
339      * and set. SurfaceFlinger will close the returned file descriptor.
340      */
341     int retireFenceFd;
342 
343     union {
344         /* Fields only relevant for HWC_DEVICE_VERSION_1_0. */
345         struct {
346             /* (dpy, sur) is the target of SurfaceFlinger's OpenGL ES
347              * composition for HWC_DEVICE_VERSION_1_0. They aren't relevant to
348              * prepare. The set call should commit this surface atomically to
349              * the display along with any overlay layers.
350              */
351             hwc_display_t dpy;
352             hwc_surface_t sur;
353         };
354 
355         /* These fields are used for virtual displays when the h/w composer
356          * version is at least HWC_DEVICE_VERSION_1_3. */
357         struct {
358             /* outbuf is the buffer that receives the composed image for
359              * virtual displays. Writes to the outbuf must wait until
360              * outbufAcquireFenceFd signals. A fence that will signal when
361              * writes to outbuf are complete should be returned in
362              * retireFenceFd.
363              *
364              * This field is set before prepare(), so properties of the buffer
365              * can be used to decide which layers can be handled by h/w
366              * composer.
367              *
368              * If prepare() sets all layers to FRAMEBUFFER, then GLES
369              * composition will happen directly to the output buffer. In this
370              * case, both outbuf and the FRAMEBUFFER_TARGET layer's buffer will
371              * be the same, and set() has no work to do besides managing fences.
372              *
373              * If the TARGET_FORCE_HWC_FOR_VIRTUAL_DISPLAYS board config
374              * variable is defined (not the default), then this behavior is
375              * changed: if all layers are marked for FRAMEBUFFER, GLES
376              * composition will take place to a scratch framebuffer, and
377              * h/w composer must copy it to the output buffer. This allows the
378              * h/w composer to do format conversion if there are cases where
379              * that is more desirable than doing it in the GLES driver or at the
380              * virtual display consumer.
381              *
382              * If some or all layers are marked OVERLAY, then the framebuffer
383              * and output buffer will be different. As with physical displays,
384              * the framebuffer handle will not change between frames if all
385              * layers are marked for OVERLAY.
386              */
387             buffer_handle_t outbuf;
388 
389             /* File descriptor for a fence that will signal when outbuf is
390              * ready to be written. The h/w composer is responsible for closing
391              * this when no longer needed.
392              *
393              * Will be -1 whenever outbuf is NULL, or when the outbuf can be
394              * written immediately.
395              */
396             int outbufAcquireFenceFd;
397         };
398     };
399 
400     /* List of layers that will be composed on the display. The buffer handles
401      * in the list will be unique. If numHwLayers is 0, all composition will be
402      * performed by SurfaceFlinger.
403      */
404     uint32_t flags;
405     size_t numHwLayers;
406     hwc_layer_1_t hwLayers[0];
407 
408 } hwc_display_contents_1_t;
409 
410 /* see hwc_composer_device::registerProcs()
411  * All of the callbacks are required and non-NULL unless otherwise noted.
412  */
413 typedef struct hwc_procs {
414     /*
415      * (*invalidate)() triggers a screen refresh, in particular prepare and set
416      * will be called shortly after this call is made. Note that there is
417      * NO GUARANTEE that the screen refresh will happen after invalidate()
418      * returns (in particular, it could happen before).
419      * invalidate() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL and
420      * it is safe to call invalidate() from any of hwc_composer_device
421      * hooks, unless noted otherwise.
422      */
423     void (*invalidate)(const struct hwc_procs* procs);
424 
425     /*
426      * (*vsync)() is called by the h/w composer HAL when a vsync event is
427      * received and HWC_EVENT_VSYNC is enabled on a display
428      * (see: hwc_event_control).
429      *
430      * the "disp" parameter indicates which display the vsync event is for.
431      * the "timestamp" parameter is the system monotonic clock timestamp in
432      *   nanosecond of when the vsync event happened.
433      *
434      * vsync() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL.
435      *
436      * It is expected that vsync() is called from a thread of at least
437      * HAL_PRIORITY_URGENT_DISPLAY with as little latency as possible,
438      * typically less than 0.5 ms.
439      *
440      * It is a (silent) error to have HWC_EVENT_VSYNC enabled when calling
441      * hwc_composer_device.set(..., 0, 0, 0) (screen off). The implementation
442      * can either stop or continue to process VSYNC events, but must not
443      * crash or cause other problems.
444      */
445     void (*vsync)(const struct hwc_procs* procs, int disp, int64_t timestamp);
446 
447     /*
448      * (*hotplug)() is called by the h/w composer HAL when a display is
449      * connected or disconnected. The PRIMARY display is always connected and
450      * the hotplug callback should not be called for it.
451      *
452      * The disp parameter indicates which display type this event is for.
453      * The connected parameter indicates whether the display has just been
454      *   connected (1) or disconnected (0).
455      *
456      * The hotplug() callback may call back into the h/w composer on the same
457      * thread to query refresh rate and dpi for the display. Additionally,
458      * other threads may be calling into the h/w composer while the callback
459      * is in progress.
460      *
461      * The h/w composer must serialize calls to the hotplug callback; only
462      * one thread may call it at a time.
463      *
464      * This callback will be NULL if the h/w composer is using
465      * HWC_DEVICE_API_VERSION_1_0.
466      */
467     void (*hotplug)(const struct hwc_procs* procs, int disp, int connected);
468 
469 } hwc_procs_t;
470 
471 
472 /*****************************************************************************/
473 
474 typedef struct hwc_module {
475     /**
476      * Common methods of the hardware composer module.  This *must* be the first member of
477      * hwc_module as users of this structure will cast a hw_module_t to
478      * hwc_module pointer in contexts where it's known the hw_module_t references a
479      * hwc_module.
480      */
481     struct hw_module_t common;
482 } hwc_module_t;
483 
484 typedef struct hwc_composer_device_1 {
485     /**
486      * Common methods of the hardware composer device.  This *must* be the first member of
487      * hwc_composer_device_1 as users of this structure will cast a hw_device_t to
488      * hwc_composer_device_1 pointer in contexts where it's known the hw_device_t references a
489      * hwc_composer_device_1.
490      */
491     struct hw_device_t common;
492 
493     /*
494      * (*prepare)() is called for each frame before composition and is used by
495      * SurfaceFlinger to determine what composition steps the HWC can handle.
496      *
497      * (*prepare)() can be called more than once, the last call prevails.
498      *
499      * The HWC responds by setting the compositionType field in each layer to
500      * either HWC_FRAMEBUFFER, HWC_OVERLAY, or HWC_CURSOR_OVERLAY. For the
501      * HWC_FRAMEBUFFER type, composition for the layer is handled by
502      * SurfaceFlinger with OpenGL ES. For the latter two overlay types,
503      * the HWC will have to handle the layer's composition. compositionType
504      * and hints are preserved between (*prepare)() calles unless the
505      * HWC_GEOMETRY_CHANGED flag is set.
506      *
507      * (*prepare)() is called with HWC_GEOMETRY_CHANGED to indicate that the
508      * list's geometry has changed, that is, when more than just the buffer's
509      * handles have been updated. Typically this happens (but is not limited to)
510      * when a window is added, removed, resized or moved. In this case
511      * compositionType and hints are reset to their default value.
512      *
513      * For HWC 1.0, numDisplays will always be one, and displays[0] will be
514      * non-NULL.
515      *
516      * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
517      * Entries for unsupported or disabled/disconnected display types will be
518      * NULL.
519      *
520      * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
521      * entries correspond to enabled virtual displays, and will be non-NULL.
522      *
523      * returns: 0 on success. An negative error code on error. If an error is
524      * returned, SurfaceFlinger will assume that none of the layer will be
525      * handled by the HWC.
526      */
527     int (*prepare)(struct hwc_composer_device_1 *dev,
528                     size_t numDisplays, hwc_display_contents_1_t** displays);
529 
530     /*
531      * (*set)() is used in place of eglSwapBuffers(), and assumes the same
532      * functionality, except it also commits the work list atomically with
533      * the actual eglSwapBuffers().
534      *
535      * The layer lists are guaranteed to be the same as the ones returned from
536      * the last call to (*prepare)().
537      *
538      * When this call returns the caller assumes that the displays will be
539      * updated in the near future with the content of their work lists, without
540      * artifacts during the transition from the previous frame.
541      *
542      * A display with zero layers indicates that the entire composition has
543      * been handled by SurfaceFlinger with OpenGL ES. In this case, (*set)()
544      * behaves just like eglSwapBuffers().
545      *
546      * For HWC 1.0, numDisplays will always be one, and displays[0] will be
547      * non-NULL.
548      *
549      * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
550      * Entries for unsupported or disabled/disconnected display types will be
551      * NULL.
552      *
553      * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
554      * entries correspond to enabled virtual displays, and will be non-NULL.
555      *
556      * IMPORTANT NOTE: There is an implicit layer containing opaque black
557      * pixels behind all the layers in the list. It is the responsibility of
558      * the hwcomposer module to make sure black pixels are output (or blended
559      * from).
560      *
561      * IMPORTANT NOTE: In the event of an error this call *MUST* still cause
562      * any fences returned in the previous call to set to eventually become
563      * signaled.  The caller may have already issued wait commands on these
564      * fences, and having set return without causing those fences to signal
565      * will likely result in a deadlock.
566      *
567      * returns: 0 on success. A negative error code on error:
568      *    HWC_EGL_ERROR: eglGetError() will provide the proper error code (only
569      *        allowed prior to HWComposer 1.1)
570      *    Another code for non EGL errors.
571      */
572     int (*set)(struct hwc_composer_device_1 *dev,
573                 size_t numDisplays, hwc_display_contents_1_t** displays);
574 
575     /*
576      * eventControl(..., event, enabled)
577      * Enables or disables h/w composer events for a display.
578      *
579      * eventControl can be called from any thread and takes effect
580      * immediately.
581      *
582      *  Supported events are:
583      *      HWC_EVENT_VSYNC
584      *
585      * returns -EINVAL if the "event" parameter is not one of the value above
586      * or if the "enabled" parameter is not 0 or 1.
587      */
588     int (*eventControl)(struct hwc_composer_device_1* dev, int disp,
589             int event, int enabled);
590 
591     union {
592         /*
593          * For HWC 1.3 and earlier, the blank() interface is used.
594          *
595          * blank(..., blank)
596          * Blanks or unblanks a display's screen.
597          *
598          * Turns the screen off when blank is nonzero, on when blank is zero.
599          * Multiple sequential calls with the same blank value must be
600          * supported.
601          * The screen state transition must be be complete when the function
602          * returns.
603          *
604          * returns 0 on success, negative on error.
605          */
606         int (*blank)(struct hwc_composer_device_1* dev, int disp, int blank);
607 
608         /*
609          * For HWC 1.4 and above, setPowerMode() will be used in place of
610          * blank().
611          *
612          * setPowerMode(..., mode)
613          * Sets the display screen's power state.
614          *
615          * Refer to the documentation of the HWC_POWER_MODE_* constants
616          * for information about each power mode.
617          *
618          * The functionality is similar to the blank() command in previous
619          * versions of HWC, but with support for more power states.
620          *
621          * The display driver is expected to retain and restore the low power
622          * state of the display while entering and exiting from suspend.
623          *
624          * Multiple sequential calls with the same mode value must be supported.
625          *
626          * The screen state transition must be be complete when the function
627          * returns.
628          *
629          * returns 0 on success, negative on error.
630          */
631         int (*setPowerMode)(struct hwc_composer_device_1* dev, int disp,
632                 int mode);
633     };
634 
635     /*
636      * Used to retrieve information about the h/w composer
637      *
638      * Returns 0 on success or -errno on error.
639      */
640     int (*query)(struct hwc_composer_device_1* dev, int what, int* value);
641 
642     /*
643      * (*registerProcs)() registers callbacks that the h/w composer HAL can
644      * later use. It will be called immediately after the composer device is
645      * opened with non-NULL procs. It is FORBIDDEN to call any of the callbacks
646      * from within registerProcs(). registerProcs() must save the hwc_procs_t
647      * pointer which is needed when calling a registered callback.
648      */
649     void (*registerProcs)(struct hwc_composer_device_1* dev,
650             hwc_procs_t const* procs);
651 
652     /*
653      * This field is OPTIONAL and can be NULL.
654      *
655      * If non NULL it will be called by SurfaceFlinger on dumpsys
656      */
657     void (*dump)(struct hwc_composer_device_1* dev, char *buff, int buff_len);
658 
659     /*
660      * (*getDisplayConfigs)() returns handles for the configurations available
661      * on the connected display. These handles must remain valid as long as the
662      * display is connected.
663      *
664      * Configuration handles are written to configs. The number of entries
665      * allocated by the caller is passed in *numConfigs; getDisplayConfigs must
666      * not try to write more than this number of config handles. On return, the
667      * total number of configurations available for the display is returned in
668      * *numConfigs. If *numConfigs is zero on entry, then configs may be NULL.
669      *
670      * Hardware composers implementing HWC_DEVICE_API_VERSION_1_3 or prior
671      * shall choose one configuration to activate and report it as the first
672      * entry in the returned list. Reporting the inactive configurations is not
673      * required.
674      *
675      * HWC_DEVICE_API_VERSION_1_4 and later provide configuration management
676      * through SurfaceFlinger, and hardware composers implementing these APIs
677      * must also provide getActiveConfig and setActiveConfig. Hardware composers
678      * implementing these API versions may choose not to activate any
679      * configuration, leaving configuration selection to higher levels of the
680      * framework.
681      *
682      * Returns 0 on success or a negative error code on error. If disp is a
683      * hotpluggable display type and no display is connected, an error shall be
684      * returned.
685      *
686      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
687      * It shall be NULL for previous versions.
688      */
689     int (*getDisplayConfigs)(struct hwc_composer_device_1* dev, int disp,
690             uint32_t* configs, size_t* numConfigs);
691 
692     /*
693      * (*getDisplayAttributes)() returns attributes for a specific config of a
694      * connected display. The config parameter is one of the config handles
695      * returned by getDisplayConfigs.
696      *
697      * The list of attributes to return is provided in the attributes
698      * parameter, terminated by HWC_DISPLAY_NO_ATTRIBUTE. The value for each
699      * requested attribute is written in order to the values array. The
700      * HWC_DISPLAY_NO_ATTRIBUTE attribute does not have a value, so the values
701      * array will have one less value than the attributes array.
702      *
703      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
704      * It shall be NULL for previous versions.
705      *
706      * If disp is a hotpluggable display type and no display is connected,
707      * or if config is not a valid configuration for the display, a negative
708      * error code shall be returned.
709      */
710     int (*getDisplayAttributes)(struct hwc_composer_device_1* dev, int disp,
711             uint32_t config, const uint32_t* attributes, int32_t* values);
712 
713     /*
714      * (*getActiveConfig)() returns the index of the configuration that is
715      * currently active on the connected display. The index is relative to
716      * the list of configuration handles returned by getDisplayConfigs. If there
717      * is no active configuration, -1 shall be returned.
718      *
719      * Returns the configuration index on success or -1 on error.
720      *
721      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later.
722      * It shall be NULL for previous versions.
723      */
724     int (*getActiveConfig)(struct hwc_composer_device_1* dev, int disp);
725 
726     /*
727      * (*setActiveConfig)() instructs the hardware composer to switch to the
728      * display configuration at the given index in the list of configuration
729      * handles returned by getDisplayConfigs.
730      *
731      * If this function returns without error, any subsequent calls to
732      * getActiveConfig shall return the index set by this function until one
733      * of the following occurs:
734      *   1) Another successful call of this function
735      *   2) The display is disconnected
736      *
737      * Returns 0 on success or a negative error code on error. If disp is a
738      * hotpluggable display type and no display is connected, or if index is
739      * outside of the range of hardware configurations returned by
740      * getDisplayConfigs, an error shall be returned.
741      *
742      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later.
743      * It shall be NULL for previous versions.
744      */
745     int (*setActiveConfig)(struct hwc_composer_device_1* dev, int disp,
746             int index);
747     /*
748      * Asynchronously update the location of the cursor layer.
749      *
750      * Within the standard prepare()/set() composition loop, the client
751      * (surfaceflinger) can request that a given layer uses dedicated cursor
752      * composition hardware by specifiying the HWC_IS_CURSOR_LAYER flag. Only
753      * one layer per display can have this flag set. If the layer is suitable
754      * for the platform's cursor hardware, hwcomposer will return from prepare()
755      * a composition type of HWC_CURSOR_OVERLAY for that layer. This indicates
756      * not only that the client is not responsible for compositing that layer,
757      * but also that the client can continue to update the position of that layer
758      * after a call to set(). This can reduce the visible latency of mouse
759      * movement to visible, on-screen cursor updates. Calls to
760      * setCursorPositionAsync() may be made from a different thread doing the
761      * prepare()/set() composition loop, but care must be taken to not interleave
762      * calls of setCursorPositionAsync() between calls of set()/prepare().
763      *
764      * Notes:
765      * - Only one layer per display can be specified as a cursor layer with
766      *   HWC_IS_CURSOR_LAYER.
767      * - hwcomposer will only return one layer per display as HWC_CURSOR_OVERLAY
768      * - This returns 0 on success or -errno on error.
769      * - This field is optional for HWC_DEVICE_API_VERSION_1_4 and later. It
770      *   should be null for previous versions.
771      */
772     int (*setCursorPositionAsync)(struct hwc_composer_device_1 *dev, int disp, int x_pos, int y_pos);
773 
774     /*
775      * Reserved for future use. Must be NULL.
776      */
777     void* reserved_proc[1];
778 
779 } hwc_composer_device_1_t;
780 
781 /** convenience API for opening and closing a device */
782 
hwc_open_1(const struct hw_module_t * module,hwc_composer_device_1_t ** device)783 static inline int hwc_open_1(const struct hw_module_t* module,
784         hwc_composer_device_1_t** device) {
785     return module->methods->open(module,
786             HWC_HARDWARE_COMPOSER, (struct hw_device_t**)device);
787 }
788 
hwc_close_1(hwc_composer_device_1_t * device)789 static inline int hwc_close_1(hwc_composer_device_1_t* device) {
790     return device->common.close(&device->common);
791 }
792 
793 /*****************************************************************************/
794 
795 __END_DECLS
796 
797 #endif /* ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H */
798