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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 /**
41  * The id of this module
42  */
43 #define HWC_HARDWARE_MODULE_ID "hwcomposer"
44 
45 /**
46  * Name of the sensors device to open
47  */
48 #define HWC_HARDWARE_COMPOSER   "composer"
49 
50 typedef struct hwc_rect {
51     int left;
52     int top;
53     int right;
54     int bottom;
55 } hwc_rect_t;
56 
57 typedef struct hwc_frect {
58     float left;
59     float top;
60     float right;
61     float bottom;
62 } hwc_frect_t;
63 
64 typedef struct hwc_region {
65     size_t numRects;
66     hwc_rect_t const* rects;
67 } hwc_region_t;
68 
69 typedef struct hwc_color {
70     uint8_t r;
71     uint8_t g;
72     uint8_t b;
73     uint8_t a;
74 } hwc_color_t;
75 
76 typedef struct hwc_layer_1 {
77     /*
78      * compositionType is used to specify this layer's type and is set by either
79      * the hardware composer implementation, or by the caller (see below).
80      *
81      *  This field is always reset to HWC_BACKGROUND or HWC_FRAMEBUFFER
82      *  before (*prepare)() is called when the HWC_GEOMETRY_CHANGED flag is
83      *  also set, otherwise, this field is preserved between (*prepare)()
84      *  calls.
85      *
86      * HWC_BACKGROUND
87      *   Always set by the caller before calling (*prepare)(), this value
88      *   indicates this is a special "background" layer. The only valid field
89      *   is backgroundColor.
90      *   The HWC can toggle this value to HWC_FRAMEBUFFER to indicate it CANNOT
91      *   handle the background color.
92      *
93      *
94      * HWC_FRAMEBUFFER_TARGET
95      *   Always set by the caller before calling (*prepare)(), this value
96      *   indicates this layer is the framebuffer surface used as the target of
97      *   OpenGL ES composition. If the HWC sets all other layers to HWC_OVERLAY
98      *   or HWC_BACKGROUND, then no OpenGL ES composition will be done, and
99      *   this layer should be ignored during set().
100      *
101      *   This flag (and the framebuffer surface layer) will only be used if the
102      *   HWC version is HWC_DEVICE_API_VERSION_1_1 or higher. In older versions,
103      *   the OpenGL ES target surface is communicated by the (dpy, sur) fields
104      *   in hwc_compositor_device_1_t.
105      *
106      *   This value cannot be set by the HWC implementation.
107      *
108      *
109      * HWC_FRAMEBUFFER
110      *   Set by the caller before calling (*prepare)() ONLY when the
111      *   HWC_GEOMETRY_CHANGED flag is also set.
112      *
113      *   Set by the HWC implementation during (*prepare)(), this indicates
114      *   that the layer will be drawn into the framebuffer using OpenGL ES.
115      *   The HWC can toggle this value to HWC_OVERLAY to indicate it will
116      *   handle the layer.
117      *
118      *
119      * HWC_OVERLAY
120      *   Set by the HWC implementation during (*prepare)(), this indicates
121      *   that the layer will be handled by the HWC (ie: it must not be
122      *   composited with OpenGL ES).
123      *
124      *
125      * HWC_SIDEBAND
126      *   Set by the caller before calling (*prepare)(), this value indicates
127      *   the contents of this layer come from a sideband video stream.
128      *
129      *   The h/w composer is responsible for receiving new image buffers from
130      *   the stream at the appropriate time (e.g. synchronized to a separate
131      *   audio stream), compositing them with the current contents of other
132      *   layers, and displaying the resulting image. This happens
133      *   independently of the normal prepare/set cycle. The prepare/set calls
134      *   only happen when other layers change, or when properties of the
135      *   sideband layer such as position or size change.
136      *
137      *   If the h/w composer can't handle the layer as a sideband stream for
138      *   some reason (e.g. unsupported scaling/blending/rotation, or too many
139      *   sideband layers) it can set compositionType to HWC_FRAMEBUFFER in
140      *   (*prepare)(). However, doing so will result in the layer being shown
141      *   as a solid color since the platform is not currently able to composite
142      *   sideband layers with the GPU. This may be improved in future
143      *   versions of the platform.
144      *
145      *
146      * HWC_CURSOR_OVERLAY
147      *   Set by the HWC implementation during (*prepare)(), this value
148      *   indicates the layer's composition will now be handled by the HWC.
149      *   Additionally, the client can now asynchronously update the on-screen
150      *   position of this layer using the setCursorPositionAsync() api.
151      */
152     int32_t compositionType;
153 
154     /*
155      * hints is bit mask set by the HWC implementation during (*prepare)().
156      * It is preserved between (*prepare)() calls, unless the
157      * HWC_GEOMETRY_CHANGED flag is set, in which case it is reset to 0.
158      *
159      * see hwc_layer_t::hints
160      */
161     uint32_t hints;
162 
163     /* see hwc_layer_t::flags */
164     uint32_t flags;
165 
166     union {
167         /* color of the background.  hwc_color_t.a is ignored */
168         hwc_color_t backgroundColor;
169 
170         struct {
171             union {
172                 /* When compositionType is HWC_FRAMEBUFFER, HWC_OVERLAY,
173                  * HWC_FRAMEBUFFER_TARGET, this is the handle of the buffer to
174                  * compose. This handle is guaranteed to have been allocated
175                  * from gralloc using the GRALLOC_USAGE_HW_COMPOSER usage flag.
176                  * If the layer's handle is unchanged across two consecutive
177                  * prepare calls and the HWC_GEOMETRY_CHANGED flag is not set
178                  * for the second call then the HWComposer implementation may
179                  * assume that the contents of the buffer have not changed. */
180                 buffer_handle_t handle;
181 
182                 /* When compositionType is HWC_SIDEBAND, this is the handle
183                  * of the sideband video stream to compose. */
184                 const native_handle_t* sidebandStream;
185             };
186 
187             /* transformation to apply to the buffer during composition */
188             uint32_t transform;
189 
190             /* blending to apply during composition */
191             int32_t blending;
192 
193             /* area of the source to consider, the origin is the top-left corner of
194              * the buffer. As of HWC_DEVICE_API_VERSION_1_3, sourceRect uses floats.
195              * If the h/w can't support a non-integer source crop rectangle, it should
196              * punt to OpenGL ES composition.
197              */
198             union {
199                 // crop rectangle in integer (pre HWC_DEVICE_API_VERSION_1_3)
200                 hwc_rect_t sourceCropi;
201                 hwc_rect_t sourceCrop; // just for source compatibility
202                 // crop rectangle in floats (as of HWC_DEVICE_API_VERSION_1_3)
203                 hwc_frect_t sourceCropf;
204             };
205 
206             /* where to composite the sourceCrop onto the display. The sourceCrop
207              * is scaled using linear filtering to the displayFrame. The origin is the
208              * top-left corner of the screen.
209              */
210             hwc_rect_t displayFrame;
211 
212             /* visible region in screen space. The origin is the
213              * top-left corner of the screen.
214              * The visible region INCLUDES areas overlapped by a translucent layer.
215              */
216             hwc_region_t visibleRegionScreen;
217 
218             /* Sync fence object that will be signaled when the buffer's
219              * contents are available. May be -1 if the contents are already
220              * available. This field is only valid during set(), and should be
221              * ignored during prepare(). The set() call must not wait for the
222              * fence to be signaled before returning, but the HWC must wait for
223              * all buffers to be signaled before reading from them.
224              *
225              * HWC_FRAMEBUFFER layers will never have an acquire fence, since
226              * reads from them are complete before the framebuffer is ready for
227              * display.
228              *
229              * HWC_SIDEBAND layers will never have an acquire fence, since
230              * synchronization is handled through implementation-defined
231              * sideband mechanisms.
232              *
233              * The HWC takes ownership of the acquireFenceFd and is responsible
234              * for closing it when no longer needed.
235              */
236             int acquireFenceFd;
237 
238             /* During set() the HWC must set this field to a file descriptor for
239              * a sync fence object that will signal after the HWC has finished
240              * reading from the buffer. The field is ignored by prepare(). Each
241              * layer should have a unique file descriptor, even if more than one
242              * refer to the same underlying fence object; this allows each to be
243              * closed independently.
244              *
245              * If buffer reads can complete at significantly different times,
246              * then using independent fences is preferred. For example, if the
247              * HWC handles some layers with a blit engine and others with
248              * overlays, then the blit layers can be reused immediately after
249              * the blit completes, but the overlay layers can't be reused until
250              * a subsequent frame has been displayed.
251              *
252              * Since HWC doesn't read from HWC_FRAMEBUFFER layers, it shouldn't
253              * produce a release fence for them. The releaseFenceFd will be -1
254              * for these layers when set() is called.
255              *
256              * Since HWC_SIDEBAND buffers don't pass through the HWC client,
257              * the HWC shouldn't produce a release fence for them. The
258              * releaseFenceFd will be -1 for these layers when set() is called.
259              *
260              * The HWC client taks ownership of the releaseFenceFd and is
261              * responsible for closing it when no longer needed.
262              */
263             int releaseFenceFd;
264 
265             /*
266              * Availability: HWC_DEVICE_API_VERSION_1_2
267              *
268              * Alpha value applied to the whole layer. The effective
269              * value of each pixel is computed as:
270              *
271              *   if (blending == HWC_BLENDING_PREMULT)
272              *      pixel.rgb = pixel.rgb * planeAlpha / 255
273              *   pixel.a = pixel.a * planeAlpha / 255
274              *
275              * Then blending proceeds as usual according to the "blending"
276              * field above.
277              *
278              * NOTE: planeAlpha applies to YUV layers as well:
279              *
280              *   pixel.rgb = yuv_to_rgb(pixel.yuv)
281              *   if (blending == HWC_BLENDING_PREMULT)
282              *      pixel.rgb = pixel.rgb * planeAlpha / 255
283              *   pixel.a = planeAlpha
284              *
285              *
286              * IMPLEMENTATION NOTE:
287              *
288              * If the source image doesn't have an alpha channel, then
289              * the h/w can use the HWC_BLENDING_COVERAGE equations instead of
290              * HWC_BLENDING_PREMULT and simply set the alpha channel to
291              * planeAlpha.
292              *
293              * e.g.:
294              *
295              *   if (blending == HWC_BLENDING_PREMULT)
296              *      blending = HWC_BLENDING_COVERAGE;
297              *   pixel.a = planeAlpha;
298              *
299              */
300             uint8_t planeAlpha;
301 
302             /* reserved for future use */
303             uint8_t _pad[3];
304         };
305     };
306 
307 #ifdef __LP64__
308     /*
309      * For 64-bit mode, this struct is 120 bytes (and 8-byte aligned), and needs
310      * to be padded as such to maintain binary compatibility.
311      */
312     uint8_t reserved[120 - 96];
313 #else
314     /*
315      * For 32-bit mode, this struct is 96 bytes, and needs to be padded as such
316      * to maintain binary compatibility.
317      */
318     uint8_t reserved[96 - 76];
319 #endif
320 
321 } hwc_layer_1_t;
322 
323 /* This represents a display, typically an EGLDisplay object */
324 typedef void* hwc_display_t;
325 
326 /* This represents a surface, typically an EGLSurface object  */
327 typedef void* hwc_surface_t;
328 
329 /*
330  * hwc_display_contents_1_t::flags values
331  */
332 enum {
333     /*
334      * HWC_GEOMETRY_CHANGED is set by SurfaceFlinger to indicate that the list
335      * passed to (*prepare)() has changed by more than just the buffer handles
336      * and acquire fences.
337      */
338     HWC_GEOMETRY_CHANGED = 0x00000001,
339 };
340 
341 /*
342  * Description of the contents to output on a display.
343  *
344  * This is the top-level structure passed to the prepare and set calls to
345  * negotiate and commit the composition of a display image.
346  */
347 typedef struct hwc_display_contents_1 {
348     /* File descriptor referring to a Sync HAL fence object which will signal
349      * when this composition is retired. For a physical display, a composition
350      * is retired when it has been replaced on-screen by a subsequent set. For
351      * a virtual display, the composition is retired when the writes to
352      * outputBuffer are complete and can be read. The fence object is created
353      * and returned by the set call; this field will be -1 on entry to prepare
354      * and set. SurfaceFlinger will close the returned file descriptor.
355      */
356     int retireFenceFd;
357 
358     union {
359         /* Fields only relevant for HWC_DEVICE_VERSION_1_0. */
360         struct {
361             /* (dpy, sur) is the target of SurfaceFlinger's OpenGL ES
362              * composition for HWC_DEVICE_VERSION_1_0. They aren't relevant to
363              * prepare. The set call should commit this surface atomically to
364              * the display along with any overlay layers.
365              */
366             hwc_display_t dpy;
367             hwc_surface_t sur;
368         };
369 
370         /* These fields are used for virtual displays when the h/w composer
371          * version is at least HWC_DEVICE_VERSION_1_3. */
372         struct {
373             /* outbuf is the buffer that receives the composed image for
374              * virtual displays. Writes to the outbuf must wait until
375              * outbufAcquireFenceFd signals. A fence that will signal when
376              * writes to outbuf are complete should be returned in
377              * retireFenceFd.
378              *
379              * This field is set before prepare(), so properties of the buffer
380              * can be used to decide which layers can be handled by h/w
381              * composer.
382              *
383              * If prepare() sets all layers to FRAMEBUFFER, then GLES
384              * composition will happen directly to the output buffer. In this
385              * case, both outbuf and the FRAMEBUFFER_TARGET layer's buffer will
386              * be the same, and set() has no work to do besides managing fences.
387              *
388              * If the TARGET_FORCE_HWC_FOR_VIRTUAL_DISPLAYS board config
389              * variable is defined (not the default), then this behavior is
390              * changed: if all layers are marked for FRAMEBUFFER, GLES
391              * composition will take place to a scratch framebuffer, and
392              * h/w composer must copy it to the output buffer. This allows the
393              * h/w composer to do format conversion if there are cases where
394              * that is more desirable than doing it in the GLES driver or at the
395              * virtual display consumer.
396              *
397              * If some or all layers are marked OVERLAY, then the framebuffer
398              * and output buffer will be different. As with physical displays,
399              * the framebuffer handle will not change between frames if all
400              * layers are marked for OVERLAY.
401              */
402             buffer_handle_t outbuf;
403 
404             /* File descriptor for a fence that will signal when outbuf is
405              * ready to be written. The h/w composer is responsible for closing
406              * this when no longer needed.
407              *
408              * Will be -1 whenever outbuf is NULL, or when the outbuf can be
409              * written immediately.
410              */
411             int outbufAcquireFenceFd;
412         };
413     };
414 
415     /* List of layers that will be composed on the display. The buffer handles
416      * in the list will be unique. If numHwLayers is 0, all composition will be
417      * performed by SurfaceFlinger.
418      */
419     uint32_t flags;
420     size_t numHwLayers;
421     hwc_layer_1_t hwLayers[0];
422 
423 } hwc_display_contents_1_t;
424 
425 /* see hwc_composer_device::registerProcs()
426  * All of the callbacks are required and non-NULL unless otherwise noted.
427  */
428 typedef struct hwc_procs {
429     /*
430      * (*invalidate)() triggers a screen refresh, in particular prepare and set
431      * will be called shortly after this call is made. Note that there is
432      * NO GUARANTEE that the screen refresh will happen after invalidate()
433      * returns (in particular, it could happen before).
434      * invalidate() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL and
435      * it is safe to call invalidate() from any of hwc_composer_device
436      * hooks, unless noted otherwise.
437      */
438     void (*invalidate)(const struct hwc_procs* procs);
439 
440     /*
441      * (*vsync)() is called by the h/w composer HAL when a vsync event is
442      * received and HWC_EVENT_VSYNC is enabled on a display
443      * (see: hwc_event_control).
444      *
445      * the "disp" parameter indicates which display the vsync event is for.
446      * the "timestamp" parameter is the system monotonic clock timestamp in
447      *   nanosecond of when the vsync event happened.
448      *
449      * vsync() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL.
450      *
451      * It is expected that vsync() is called from a thread of at least
452      * HAL_PRIORITY_URGENT_DISPLAY with as little latency as possible,
453      * typically less than 0.5 ms.
454      *
455      * It is a (silent) error to have HWC_EVENT_VSYNC enabled when calling
456      * hwc_composer_device.set(..., 0, 0, 0) (screen off). The implementation
457      * can either stop or continue to process VSYNC events, but must not
458      * crash or cause other problems.
459      */
460     void (*vsync)(const struct hwc_procs* procs, int disp, int64_t timestamp);
461 
462     /*
463      * (*hotplug)() is called by the h/w composer HAL when a display is
464      * connected or disconnected. The PRIMARY display is always connected and
465      * the hotplug callback should not be called for it.
466      *
467      * The disp parameter indicates which display type this event is for.
468      * The connected parameter indicates whether the display has just been
469      *   connected (1) or disconnected (0).
470      *
471      * The hotplug() callback may call back into the h/w composer on the same
472      * thread to query refresh rate and dpi for the display. Additionally,
473      * other threads may be calling into the h/w composer while the callback
474      * is in progress.
475      *
476      * The h/w composer must serialize calls to the hotplug callback; only
477      * one thread may call it at a time.
478      *
479      * This callback will be NULL if the h/w composer is using
480      * HWC_DEVICE_API_VERSION_1_0.
481      */
482     void (*hotplug)(const struct hwc_procs* procs, int disp, int connected);
483 
484 } hwc_procs_t;
485 
486 
487 /*****************************************************************************/
488 
489 typedef struct hwc_module {
490     /**
491      * Common methods of the hardware composer module.  This *must* be the first member of
492      * hwc_module as users of this structure will cast a hw_module_t to
493      * hwc_module pointer in contexts where it's known the hw_module_t references a
494      * hwc_module.
495      */
496     struct hw_module_t common;
497 } hwc_module_t;
498 
499 typedef struct hwc_composer_device_1 {
500     /**
501      * Common methods of the hardware composer device.  This *must* be the first member of
502      * hwc_composer_device_1 as users of this structure will cast a hw_device_t to
503      * hwc_composer_device_1 pointer in contexts where it's known the hw_device_t references a
504      * hwc_composer_device_1.
505      */
506     struct hw_device_t common;
507 
508     /*
509      * (*prepare)() is called for each frame before composition and is used by
510      * SurfaceFlinger to determine what composition steps the HWC can handle.
511      *
512      * (*prepare)() can be called more than once, the last call prevails.
513      *
514      * The HWC responds by setting the compositionType field in each layer to
515      * either HWC_FRAMEBUFFER, HWC_OVERLAY, or HWC_CURSOR_OVERLAY. For the
516      * HWC_FRAMEBUFFER type, composition for the layer is handled by
517      * SurfaceFlinger with OpenGL ES. For the latter two overlay types,
518      * the HWC will have to handle the layer's composition. compositionType
519      * and hints are preserved between (*prepare)() calles unless the
520      * HWC_GEOMETRY_CHANGED flag is set.
521      *
522      * (*prepare)() is called with HWC_GEOMETRY_CHANGED to indicate that the
523      * list's geometry has changed, that is, when more than just the buffer's
524      * handles have been updated. Typically this happens (but is not limited to)
525      * when a window is added, removed, resized or moved. In this case
526      * compositionType and hints are reset to their default value.
527      *
528      * For HWC 1.0, numDisplays will always be one, and displays[0] will be
529      * non-NULL.
530      *
531      * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
532      * Entries for unsupported or disabled/disconnected display types will be
533      * NULL.
534      *
535      * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
536      * entries correspond to enabled virtual displays, and will be non-NULL.
537      *
538      * returns: 0 on success. An negative error code on error. If an error is
539      * returned, SurfaceFlinger will assume that none of the layer will be
540      * handled by the HWC.
541      */
542     int (*prepare)(struct hwc_composer_device_1 *dev,
543                     size_t numDisplays, hwc_display_contents_1_t** displays);
544 
545     /*
546      * (*set)() is used in place of eglSwapBuffers(), and assumes the same
547      * functionality, except it also commits the work list atomically with
548      * the actual eglSwapBuffers().
549      *
550      * The layer lists are guaranteed to be the same as the ones returned from
551      * the last call to (*prepare)().
552      *
553      * When this call returns the caller assumes that the displays will be
554      * updated in the near future with the content of their work lists, without
555      * artifacts during the transition from the previous frame.
556      *
557      * A display with zero layers indicates that the entire composition has
558      * been handled by SurfaceFlinger with OpenGL ES. In this case, (*set)()
559      * behaves just like eglSwapBuffers().
560      *
561      * For HWC 1.0, numDisplays will always be one, and displays[0] will be
562      * non-NULL.
563      *
564      * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
565      * Entries for unsupported or disabled/disconnected display types will be
566      * NULL.
567      *
568      * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
569      * entries correspond to enabled virtual displays, and will be non-NULL.
570      *
571      * IMPORTANT NOTE: There is an implicit layer containing opaque black
572      * pixels behind all the layers in the list. It is the responsibility of
573      * the hwcomposer module to make sure black pixels are output (or blended
574      * from).
575      *
576      * IMPORTANT NOTE: In the event of an error this call *MUST* still cause
577      * any fences returned in the previous call to set to eventually become
578      * signaled.  The caller may have already issued wait commands on these
579      * fences, and having set return without causing those fences to signal
580      * will likely result in a deadlock.
581      *
582      * returns: 0 on success. A negative error code on error:
583      *    HWC_EGL_ERROR: eglGetError() will provide the proper error code (only
584      *        allowed prior to HWComposer 1.1)
585      *    Another code for non EGL errors.
586      */
587     int (*set)(struct hwc_composer_device_1 *dev,
588                 size_t numDisplays, hwc_display_contents_1_t** displays);
589 
590     /*
591      * eventControl(..., event, enabled)
592      * Enables or disables h/w composer events for a display.
593      *
594      * eventControl can be called from any thread and takes effect
595      * immediately.
596      *
597      *  Supported events are:
598      *      HWC_EVENT_VSYNC
599      *
600      * returns -EINVAL if the "event" parameter is not one of the value above
601      * or if the "enabled" parameter is not 0 or 1.
602      */
603     int (*eventControl)(struct hwc_composer_device_1* dev, int disp,
604             int event, int enabled);
605 
606     union {
607         /*
608          * For HWC 1.3 and earlier, the blank() interface is used.
609          *
610          * blank(..., blank)
611          * Blanks or unblanks a display's screen.
612          *
613          * Turns the screen off when blank is nonzero, on when blank is zero.
614          * Multiple sequential calls with the same blank value must be
615          * supported.
616          * The screen state transition must be be complete when the function
617          * returns.
618          *
619          * returns 0 on success, negative on error.
620          */
621         int (*blank)(struct hwc_composer_device_1* dev, int disp, int blank);
622 
623         /*
624          * For HWC 1.4 and above, setPowerMode() will be used in place of
625          * blank().
626          *
627          * setPowerMode(..., mode)
628          * Sets the display screen's power state.
629          *
630          * Refer to the documentation of the HWC_POWER_MODE_* constants
631          * for information about each power mode.
632          *
633          * The functionality is similar to the blank() command in previous
634          * versions of HWC, but with support for more power states.
635          *
636          * The display driver is expected to retain and restore the low power
637          * state of the display while entering and exiting from suspend.
638          *
639          * Multiple sequential calls with the same mode value must be supported.
640          *
641          * The screen state transition must be be complete when the function
642          * returns.
643          *
644          * returns 0 on success, negative on error.
645          */
646         int (*setPowerMode)(struct hwc_composer_device_1* dev, int disp,
647                 int mode);
648     };
649 
650     /*
651      * Used to retrieve information about the h/w composer
652      *
653      * Returns 0 on success or -errno on error.
654      */
655     int (*query)(struct hwc_composer_device_1* dev, int what, int* value);
656 
657     /*
658      * (*registerProcs)() registers callbacks that the h/w composer HAL can
659      * later use. It will be called immediately after the composer device is
660      * opened with non-NULL procs. It is FORBIDDEN to call any of the callbacks
661      * from within registerProcs(). registerProcs() must save the hwc_procs_t
662      * pointer which is needed when calling a registered callback.
663      */
664     void (*registerProcs)(struct hwc_composer_device_1* dev,
665             hwc_procs_t const* procs);
666 
667     /*
668      * This field is OPTIONAL and can be NULL.
669      *
670      * If non NULL it will be called by SurfaceFlinger on dumpsys
671      */
672     void (*dump)(struct hwc_composer_device_1* dev, char *buff, int buff_len);
673 
674     /*
675      * (*getDisplayConfigs)() returns handles for the configurations available
676      * on the connected display. These handles must remain valid as long as the
677      * display is connected.
678      *
679      * Configuration handles are written to configs. The number of entries
680      * allocated by the caller is passed in *numConfigs; getDisplayConfigs must
681      * not try to write more than this number of config handles. On return, the
682      * total number of configurations available for the display is returned in
683      * *numConfigs. If *numConfigs is zero on entry, then configs may be NULL.
684      *
685      * Hardware composers implementing HWC_DEVICE_API_VERSION_1_3 or prior
686      * shall choose one configuration to activate and report it as the first
687      * entry in the returned list. Reporting the inactive configurations is not
688      * required.
689      *
690      * HWC_DEVICE_API_VERSION_1_4 and later provide configuration management
691      * through SurfaceFlinger, and hardware composers implementing these APIs
692      * must also provide getActiveConfig and setActiveConfig. Hardware composers
693      * implementing these API versions may choose not to activate any
694      * configuration, leaving configuration selection to higher levels of the
695      * framework.
696      *
697      * Returns 0 on success or a negative error code on error. If disp is a
698      * hotpluggable display type and no display is connected, an error shall be
699      * returned.
700      *
701      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
702      * It shall be NULL for previous versions.
703      */
704     int (*getDisplayConfigs)(struct hwc_composer_device_1* dev, int disp,
705             uint32_t* configs, size_t* numConfigs);
706 
707     /*
708      * (*getDisplayAttributes)() returns attributes for a specific config of a
709      * connected display. The config parameter is one of the config handles
710      * returned by getDisplayConfigs.
711      *
712      * The list of attributes to return is provided in the attributes
713      * parameter, terminated by HWC_DISPLAY_NO_ATTRIBUTE. The value for each
714      * requested attribute is written in order to the values array. The
715      * HWC_DISPLAY_NO_ATTRIBUTE attribute does not have a value, so the values
716      * array will have one less value than the attributes array.
717      *
718      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
719      * It shall be NULL for previous versions.
720      *
721      * If disp is a hotpluggable display type and no display is connected,
722      * or if config is not a valid configuration for the display, a negative
723      * error code shall be returned.
724      */
725     int (*getDisplayAttributes)(struct hwc_composer_device_1* dev, int disp,
726             uint32_t config, const uint32_t* attributes, int32_t* values);
727 
728     /*
729      * (*getActiveConfig)() returns the index of the configuration that is
730      * currently active on the connected display. The index is relative to
731      * the list of configuration handles returned by getDisplayConfigs. If there
732      * is no active configuration, -1 shall be returned.
733      *
734      * Returns the configuration index on success or -1 on error.
735      *
736      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later.
737      * It shall be NULL for previous versions.
738      */
739     int (*getActiveConfig)(struct hwc_composer_device_1* dev, int disp);
740 
741     /*
742      * (*setActiveConfig)() instructs the hardware composer to switch to the
743      * display configuration at the given index in the list of configuration
744      * handles returned by getDisplayConfigs.
745      *
746      * If this function returns without error, any subsequent calls to
747      * getActiveConfig shall return the index set by this function until one
748      * of the following occurs:
749      *   1) Another successful call of this function
750      *   2) The display is disconnected
751      *
752      * Returns 0 on success or a negative error code on error. If disp is a
753      * hotpluggable display type and no display is connected, or if index is
754      * outside of the range of hardware configurations returned by
755      * getDisplayConfigs, an error shall be returned.
756      *
757      * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later.
758      * It shall be NULL for previous versions.
759      */
760     int (*setActiveConfig)(struct hwc_composer_device_1* dev, int disp,
761             int index);
762     /*
763      * Asynchronously update the location of the cursor layer.
764      *
765      * Within the standard prepare()/set() composition loop, the client
766      * (surfaceflinger) can request that a given layer uses dedicated cursor
767      * composition hardware by specifiying the HWC_IS_CURSOR_LAYER flag. Only
768      * one layer per display can have this flag set. If the layer is suitable
769      * for the platform's cursor hardware, hwcomposer will return from prepare()
770      * a composition type of HWC_CURSOR_OVERLAY for that layer. This indicates
771      * not only that the client is not responsible for compositing that layer,
772      * but also that the client can continue to update the position of that layer
773      * after a call to set(). This can reduce the visible latency of mouse
774      * movement to visible, on-screen cursor updates. Calls to
775      * setCursorPositionAsync() may be made from a different thread doing the
776      * prepare()/set() composition loop, but care must be taken to not interleave
777      * calls of setCursorPositionAsync() between calls of set()/prepare().
778      *
779      * Notes:
780      * - Only one layer per display can be specified as a cursor layer with
781      *   HWC_IS_CURSOR_LAYER.
782      * - hwcomposer will only return one layer per display as HWC_CURSOR_OVERLAY
783      * - This returns 0 on success or -errno on error.
784      * - This field is optional for HWC_DEVICE_API_VERSION_1_4 and later. It
785      *   should be null for previous versions.
786      */
787     int (*setCursorPositionAsync)(struct hwc_composer_device_1 *dev, int disp, int x_pos, int y_pos);
788 
789     /*
790      * Reserved for future use. Must be NULL.
791      */
792     void* reserved_proc[1];
793 
794 } hwc_composer_device_1_t;
795 
796 /** convenience API for opening and closing a device */
797 
hwc_open_1(const struct hw_module_t * module,hwc_composer_device_1_t ** device)798 static inline int hwc_open_1(const struct hw_module_t* module,
799         hwc_composer_device_1_t** device) {
800     return module->methods->open(module,
801             HWC_HARDWARE_COMPOSER, (struct hw_device_t**)device);
802 }
803 
hwc_close_1(hwc_composer_device_1_t * device)804 static inline int hwc_close_1(hwc_composer_device_1_t* device) {
805     return device->common.close(&device->common);
806 }
807 
808 /*****************************************************************************/
809 
810 __END_DECLS
811 
812 #endif /* ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H */
813