2 * Copyright (C) 2010 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #ifndef ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H
18 #define ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H
21 #include <sys/cdefs.h>
23 #include <hardware/gralloc.h>
24 #include <hardware/hardware.h>
25 #include <cutils/native_handle.h>
27 #include <hardware/hwcomposer_defs.h>
31 /*****************************************************************************/
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
38 /*****************************************************************************/
41 * The id of this module
43 #define HWC_HARDWARE_MODULE_ID "hwcomposer"
46 * Name of the sensors device to open
48 #define HWC_HARDWARE_COMPOSER "composer"
50 typedef struct hwc_rect
{
57 typedef struct hwc_frect
{
64 typedef struct hwc_region
{
66 hwc_rect_t
const* rects
;
69 typedef struct hwc_color
{
76 typedef struct hwc_layer_1
{
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).
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)()
87 * Always set by the caller before calling (*prepare)(), this value
88 * indicates this is a special "background" layer. The only valid field
90 * The HWC can toggle this value to HWC_FRAMEBUFFER to indicate it CANNOT
91 * handle the background color.
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().
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.
106 * This value cannot be set by the HWC implementation.
110 * Set by the caller before calling (*prepare)() ONLY when the
111 * HWC_GEOMETRY_CHANGED flag is also set.
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
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).
125 int32_t compositionType
;
128 * hints is bit mask set by the HWC implementation during (*prepare)().
129 * It is preserved between (*prepare)() calls, unless the
130 * HWC_GEOMETRY_CHANGED flag is set, in which case it is reset to 0.
132 * see hwc_layer_t::hints
136 /* see hwc_layer_t::flags */
140 /* color of the background. hwc_color_t.a is ignored */
141 hwc_color_t backgroundColor
;
144 /* handle of buffer to compose. This handle is guaranteed to have been
145 * allocated from gralloc using the GRALLOC_USAGE_HW_COMPOSER usage flag. If
146 * the layer's handle is unchanged across two consecutive prepare calls and
147 * the HWC_GEOMETRY_CHANGED flag is not set for the second call then the
148 * HWComposer implementation may assume that the contents of the buffer have
150 buffer_handle_t handle
;
152 /* transformation to apply to the buffer during composition */
155 /* blending to apply during composition */
158 /* area of the source to consider, the origin is the top-left corner of
159 * the buffer. As of HWC_DEVICE_API_VERSION_1_3, sourceRect uses floats.
160 * If the h/w can't support a non-integer source crop rectangle, it should
161 * punt to OpenGL ES composition.
164 // crop rectangle in integer (pre HWC_DEVICE_API_VERSION_1_3)
165 hwc_rect_t sourceCropi
;
166 hwc_rect_t sourceCrop
; // just for source compatibility
167 // crop rectangle in floats (as of HWC_DEVICE_API_VERSION_1_3)
168 hwc_frect_t sourceCropf
;
171 /* where to composite the sourceCrop onto the display. The sourceCrop
172 * is scaled using linear filtering to the displayFrame. The origin is the
173 * top-left corner of the screen.
175 hwc_rect_t displayFrame
;
177 /* visible region in screen space. The origin is the
178 * top-left corner of the screen.
179 * The visible region INCLUDES areas overlapped by a translucent layer.
181 hwc_region_t visibleRegionScreen
;
183 /* Sync fence object that will be signaled when the buffer's
184 * contents are available. May be -1 if the contents are already
185 * available. This field is only valid during set(), and should be
186 * ignored during prepare(). The set() call must not wait for the
187 * fence to be signaled before returning, but the HWC must wait for
188 * all buffers to be signaled before reading from them.
190 * HWC_FRAMEBUFFER layers will never have an acquire fence, since
191 * reads from them are complete before the framebuffer is ready for
194 * The HWC takes ownership of the acquireFenceFd and is responsible
195 * for closing it when no longer needed.
199 /* During set() the HWC must set this field to a file descriptor for
200 * a sync fence object that will signal after the HWC has finished
201 * reading from the buffer. The field is ignored by prepare(). Each
202 * layer should have a unique file descriptor, even if more than one
203 * refer to the same underlying fence object; this allows each to be
204 * closed independently.
206 * If buffer reads can complete at significantly different times,
207 * then using independent fences is preferred. For example, if the
208 * HWC handles some layers with a blit engine and others with
209 * overlays, then the blit layers can be reused immediately after
210 * the blit completes, but the overlay layers can't be reused until
211 * a subsequent frame has been displayed.
213 * Since HWC doesn't read from HWC_FRAMEBUFFER layers, it shouldn't
214 * produce a release fence for them. The releaseFenceFd will be -1
215 * for these layers when set() is called.
217 * The HWC client taks ownership of the releaseFenceFd and is
218 * responsible for closing it when no longer needed.
223 * Availability: HWC_DEVICE_API_VERSION_1_2
225 * Alpha value applied to the whole layer. The effective
226 * value of each pixel is computed as:
228 * if (blending == HWC_BLENDING_PREMULT)
229 * pixel.rgb = pixel.rgb * planeAlpha / 255
230 * pixel.a = pixel.a * planeAlpha / 255
232 * Then blending proceeds as usual according to the "blending"
235 * NOTE: planeAlpha applies to YUV layers as well:
237 * pixel.rgb = yuv_to_rgb(pixel.yuv)
238 * if (blending == HWC_BLENDING_PREMULT)
239 * pixel.rgb = pixel.rgb * planeAlpha / 255
240 * pixel.a = planeAlpha
243 * IMPLEMENTATION NOTE:
245 * If the source image doesn't have an alpha channel, then
246 * the h/w can use the HWC_BLENDING_COVERAGE equations instead of
247 * HWC_BLENDING_PREMULT and simply set the alpha channel to
252 * if (blending == HWC_BLENDING_PREMULT)
253 * blending = HWC_BLENDING_COVERAGE;
254 * pixel.a = planeAlpha;
259 /* reserved for future use */
264 /* Allow for expansion w/o breaking binary compatibility.
265 * Pad layer to 96 bytes, assuming 32-bit pointers.
267 int32_t reserved
[24 - 19];
271 /* This represents a display, typically an EGLDisplay object */
272 typedef void* hwc_display_t
;
274 /* This represents a surface, typically an EGLSurface object */
275 typedef void* hwc_surface_t
;
278 * hwc_display_contents_1_t::flags values
282 * HWC_GEOMETRY_CHANGED is set by SurfaceFlinger to indicate that the list
283 * passed to (*prepare)() has changed by more than just the buffer handles
284 * and acquire fences.
286 HWC_GEOMETRY_CHANGED
= 0x00000001,
290 * Description of the contents to output on a display.
292 * This is the top-level structure passed to the prepare and set calls to
293 * negotiate and commit the composition of a display image.
295 typedef struct hwc_display_contents_1
{
296 /* File descriptor referring to a Sync HAL fence object which will signal
297 * when this composition is retired. For a physical display, a composition
298 * is retired when it has been replaced on-screen by a subsequent set. For
299 * a virtual display, the composition is retired when the writes to
300 * outputBuffer are complete and can be read. The fence object is created
301 * and returned by the set call; this field will be -1 on entry to prepare
302 * and set. SurfaceFlinger will close the returned file descriptor.
307 /* Fields only relevant for HWC_DEVICE_VERSION_1_0. */
309 /* (dpy, sur) is the target of SurfaceFlinger's OpenGL ES
310 * composition for HWC_DEVICE_VERSION_1_0. They aren't relevant to
311 * prepare. The set call should commit this surface atomically to
312 * the display along with any overlay layers.
318 /* These fields are used for virtual displays when the h/w composer
319 * version is at least HWC_DEVICE_VERSION_1_3. */
321 /* outbuf is the buffer that receives the composed image for
322 * virtual displays. Writes to the outbuf must wait until
323 * outbufAcquireFenceFd signals. A fence that will signal when
324 * writes to outbuf are complete should be returned in
327 * This field is set before prepare(), so properties of the buffer
328 * can be used to decide which layers can be handled by h/w
331 * If prepare() sets all layers to FRAMEBUFFER, then GLES
332 * composition will happen directly to the output buffer. In this
333 * case, both outbuf and the FRAMEBUFFER_TARGET layer's buffer will
334 * be the same, and set() has no work to do besides managing fences.
336 * If the TARGET_FORCE_HWC_FOR_VIRTUAL_DISPLAYS board config
337 * variable is defined (not the default), then this behavior is
338 * changed: if all layers are marked for FRAMEBUFFER, GLES
339 * composition will take place to a scratch framebuffer, and
340 * h/w composer must copy it to the output buffer. This allows the
341 * h/w composer to do format conversion if there are cases where
342 * that is more desirable than doing it in the GLES driver or at the
343 * virtual display consumer.
345 * If some or all layers are marked OVERLAY, then the framebuffer
346 * and output buffer will be different. As with physical displays,
347 * the framebuffer handle will not change between frames if all
348 * layers are marked for OVERLAY.
350 buffer_handle_t outbuf
;
352 /* File descriptor for a fence that will signal when outbuf is
353 * ready to be written. The h/w composer is responsible for closing
354 * this when no longer needed.
356 * Will be -1 whenever outbuf is NULL, or when the outbuf can be
357 * written immediately.
359 int outbufAcquireFenceFd
;
363 /* List of layers that will be composed on the display. The buffer handles
364 * in the list will be unique. If numHwLayers is 0, all composition will be
365 * performed by SurfaceFlinger.
369 hwc_layer_1_t hwLayers
[0];
371 } hwc_display_contents_1_t
;
373 /* see hwc_composer_device::registerProcs()
374 * All of the callbacks are required and non-NULL unless otherwise noted.
376 typedef struct hwc_procs
{
378 * (*invalidate)() triggers a screen refresh, in particular prepare and set
379 * will be called shortly after this call is made. Note that there is
380 * NO GUARANTEE that the screen refresh will happen after invalidate()
381 * returns (in particular, it could happen before).
382 * invalidate() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL and
383 * it is safe to call invalidate() from any of hwc_composer_device
384 * hooks, unless noted otherwise.
386 void (*invalidate
)(const struct hwc_procs
* procs
);
389 * (*vsync)() is called by the h/w composer HAL when a vsync event is
390 * received and HWC_EVENT_VSYNC is enabled on a display
391 * (see: hwc_event_control).
393 * the "disp" parameter indicates which display the vsync event is for.
394 * the "timestamp" parameter is the system monotonic clock timestamp in
395 * nanosecond of when the vsync event happened.
397 * vsync() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL.
399 * It is expected that vsync() is called from a thread of at least
400 * HAL_PRIORITY_URGENT_DISPLAY with as little latency as possible,
401 * typically less than 0.5 ms.
403 * It is a (silent) error to have HWC_EVENT_VSYNC enabled when calling
404 * hwc_composer_device.set(..., 0, 0, 0) (screen off). The implementation
405 * can either stop or continue to process VSYNC events, but must not
406 * crash or cause other problems.
408 void (*vsync
)(const struct hwc_procs
* procs
, int disp
, int64_t timestamp
);
411 * (*hotplug)() is called by the h/w composer HAL when a display is
412 * connected or disconnected. The PRIMARY display is always connected and
413 * the hotplug callback should not be called for it.
415 * The disp parameter indicates which display type this event is for.
416 * The connected parameter indicates whether the display has just been
417 * connected (1) or disconnected (0).
419 * The hotplug() callback may call back into the h/w composer on the same
420 * thread to query refresh rate and dpi for the display. Additionally,
421 * other threads may be calling into the h/w composer while the callback
424 * The h/w composer must serialize calls to the hotplug callback; only
425 * one thread may call it at a time.
427 * This callback will be NULL if the h/w composer is using
428 * HWC_DEVICE_API_VERSION_1_0.
430 void (*hotplug
)(const struct hwc_procs
* procs
, int disp
, int connected
);
435 /*****************************************************************************/
437 typedef struct hwc_module
{
438 struct hw_module_t common
;
441 typedef struct hwc_composer_device_1
{
442 struct hw_device_t common
;
445 * (*prepare)() is called for each frame before composition and is used by
446 * SurfaceFlinger to determine what composition steps the HWC can handle.
448 * (*prepare)() can be called more than once, the last call prevails.
450 * The HWC responds by setting the compositionType field in each layer to
451 * either HWC_FRAMEBUFFER or HWC_OVERLAY. In the former case, the
452 * composition for the layer is handled by SurfaceFlinger with OpenGL ES,
453 * in the later case, the HWC will have to handle the layer's composition.
454 * compositionType and hints are preserved between (*prepare)() calles
455 * unless the HWC_GEOMETRY_CHANGED flag is set.
457 * (*prepare)() is called with HWC_GEOMETRY_CHANGED to indicate that the
458 * list's geometry has changed, that is, when more than just the buffer's
459 * handles have been updated. Typically this happens (but is not limited to)
460 * when a window is added, removed, resized or moved. In this case
461 * compositionType and hints are reset to their default value.
463 * For HWC 1.0, numDisplays will always be one, and displays[0] will be
466 * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
467 * Entries for unsupported or disabled/disconnected display types will be
470 * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
471 * entries correspond to enabled virtual displays, and will be non-NULL.
473 * returns: 0 on success. An negative error code on error. If an error is
474 * returned, SurfaceFlinger will assume that none of the layer will be
475 * handled by the HWC.
477 int (*prepare
)(struct hwc_composer_device_1
*dev
,
478 size_t numDisplays
, hwc_display_contents_1_t
** displays
);
481 * (*set)() is used in place of eglSwapBuffers(), and assumes the same
482 * functionality, except it also commits the work list atomically with
483 * the actual eglSwapBuffers().
485 * The layer lists are guaranteed to be the same as the ones returned from
486 * the last call to (*prepare)().
488 * When this call returns the caller assumes that the displays will be
489 * updated in the near future with the content of their work lists, without
490 * artifacts during the transition from the previous frame.
492 * A display with zero layers indicates that the entire composition has
493 * been handled by SurfaceFlinger with OpenGL ES. In this case, (*set)()
494 * behaves just like eglSwapBuffers().
496 * For HWC 1.0, numDisplays will always be one, and displays[0] will be
499 * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES.
500 * Entries for unsupported or disabled/disconnected display types will be
503 * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra
504 * entries correspond to enabled virtual displays, and will be non-NULL.
506 * IMPORTANT NOTE: There is an implicit layer containing opaque black
507 * pixels behind all the layers in the list. It is the responsibility of
508 * the hwcomposer module to make sure black pixels are output (or blended
511 * IMPORTANT NOTE: In the event of an error this call *MUST* still cause
512 * any fences returned in the previous call to set to eventually become
513 * signaled. The caller may have already issued wait commands on these
514 * fences, and having set return without causing those fences to signal
515 * will likely result in a deadlock.
517 * returns: 0 on success. A negative error code on error:
518 * HWC_EGL_ERROR: eglGetError() will provide the proper error code (only
519 * allowed prior to HWComposer 1.1)
520 * Another code for non EGL errors.
522 int (*set
)(struct hwc_composer_device_1
*dev
,
523 size_t numDisplays
, hwc_display_contents_1_t
** displays
);
526 * eventControl(..., event, enabled)
527 * Enables or disables h/w composer events for a display.
529 * eventControl can be called from any thread and takes effect
532 * Supported events are:
535 * returns -EINVAL if the "event" parameter is not one of the value above
536 * or if the "enabled" parameter is not 0 or 1.
538 int (*eventControl
)(struct hwc_composer_device_1
* dev
, int disp
,
539 int event
, int enabled
);
543 * Blanks or unblanks a display's screen.
545 * Turns the screen off when blank is nonzero, on when blank is zero.
546 * Multiple sequential calls with the same blank value must be supported.
547 * The screen state transition must be be complete when the function
550 * returns 0 on success, negative on error.
552 int (*blank
)(struct hwc_composer_device_1
* dev
, int disp
, int blank
);
555 * Used to retrieve information about the h/w composer
557 * Returns 0 on success or -errno on error.
559 int (*query
)(struct hwc_composer_device_1
* dev
, int what
, int* value
);
562 * (*registerProcs)() registers callbacks that the h/w composer HAL can
563 * later use. It will be called immediately after the composer device is
564 * opened with non-NULL procs. It is FORBIDDEN to call any of the callbacks
565 * from within registerProcs(). registerProcs() must save the hwc_procs_t
566 * pointer which is needed when calling a registered callback.
568 void (*registerProcs
)(struct hwc_composer_device_1
* dev
,
569 hwc_procs_t
const* procs
);
572 * This field is OPTIONAL and can be NULL.
574 * If non NULL it will be called by SurfaceFlinger on dumpsys
576 void (*dump
)(struct hwc_composer_device_1
* dev
, char *buff
, int buff_len
);
579 * (*getDisplayConfigs)() returns handles for the configurations available
580 * on the connected display. These handles must remain valid as long as the
581 * display is connected.
583 * Configuration handles are written to configs. The number of entries
584 * allocated by the caller is passed in *numConfigs; getDisplayConfigs must
585 * not try to write more than this number of config handles. On return, the
586 * total number of configurations available for the display is returned in
587 * *numConfigs. If *numConfigs is zero on entry, then configs may be NULL.
589 * HWC_DEVICE_API_VERSION_1_1 does not provide a way to choose a config.
590 * For displays that support multiple configurations, the h/w composer
591 * implementation should choose one and report it as the first config in
592 * the list. Reporting the not-chosen configs is not required.
594 * Returns 0 on success or -errno on error. If disp is a hotpluggable
595 * display type and no display is connected, an error should be returned.
597 * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
598 * It should be NULL for previous versions.
600 int (*getDisplayConfigs
)(struct hwc_composer_device_1
* dev
, int disp
,
601 uint32_t* configs
, size_t* numConfigs
);
604 * (*getDisplayAttributes)() returns attributes for a specific config of a
605 * connected display. The config parameter is one of the config handles
606 * returned by getDisplayConfigs.
608 * The list of attributes to return is provided in the attributes
609 * parameter, terminated by HWC_DISPLAY_NO_ATTRIBUTE. The value for each
610 * requested attribute is written in order to the values array. The
611 * HWC_DISPLAY_NO_ATTRIBUTE attribute does not have a value, so the values
612 * array will have one less value than the attributes array.
614 * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later.
615 * It should be NULL for previous versions.
617 * If disp is a hotpluggable display type and no display is connected,
618 * or if config is not a valid configuration for the display, a negative
619 * value should be returned.
621 int (*getDisplayAttributes
)(struct hwc_composer_device_1
* dev
, int disp
,
622 uint32_t config
, const uint32_t* attributes
, int32_t* values
);
625 * Reserved for future use. Must be NULL.
627 void* reserved_proc
[4];
629 } hwc_composer_device_1_t
;
631 /** convenience API for opening and closing a device */
633 static inline int hwc_open_1(const struct hw_module_t
* module
,
634 hwc_composer_device_1_t
** device
) {
635 return module
->methods
->open(module
,
636 HWC_HARDWARE_COMPOSER
, (struct hw_device_t
**)device
);
639 static inline int hwc_close_1(hwc_composer_device_1_t
* device
) {
640 return device
->common
.close(&device
->common
);
643 /*****************************************************************************/
647 #endif /* ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H */