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 /*

  * Copyright (C) 2008 The Android Open Source Project

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 #ifndef ANDROID_GRALLOC_INTERFACE_H

 #define ANDROID_GRALLOC_INTERFACE_H

 #include <cutils/native_handle.h>

 #include <hardware/hardware.h>

 #include <stdint.h>

 #include <sys/cdefs.h>

 #include <sys/types.h>

 __BEGIN_DECLS

 /**

  * The id of this module

  */

 #define GRALLOC_HARDWARE_MODULE_ID "gralloc"

 /**

  * Name of the graphics device to open

  */

 #define GRALLOC_HARDWARE_FB0 "fb0"

 #define GRALLOC_HARDWARE_GPU0 "gpu0"

 enum {

     /* buffer is never read in software */

     GRALLOC_USAGE_SW_READ_NEVER   = 0x00000000,

     /* buffer is rarely read in software */

     GRALLOC_USAGE_SW_READ_RARELY  = 0x00000002,

     /* buffer is often read in software */

     GRALLOC_USAGE_SW_READ_OFTEN   = 0x00000003,

     /* mask for the software read values */

     GRALLOC_USAGE_SW_READ_MASK    = 0x0000000F,

     /* buffer is never written in software */

     GRALLOC_USAGE_SW_WRITE_NEVER  = 0x00000000,

     /* buffer is never written in software */

     GRALLOC_USAGE_SW_WRITE_RARELY = 0x00000020,

     /* buffer is never written in software */

     GRALLOC_USAGE_SW_WRITE_OFTEN  = 0x00000030,

     /* mask for the software write values */

     GRALLOC_USAGE_SW_WRITE_MASK   = 0x000000F0,

     /* buffer will be used as an OpenGL ES texture */

     GRALLOC_USAGE_HW_TEXTURE      = 0x00000100,

     /* buffer will be used as an OpenGL ES render target */

     GRALLOC_USAGE_HW_RENDER       = 0x00000200,

     /* buffer will be used by the 2D hardware blitter */

     GRALLOC_USAGE_HW_2D           = 0x00000C00,

     /* buffer will be used with the framebuffer device */

     GRALLOC_USAGE_HW_FB           = 0x00001000,

     /* mask for the software usage bit-mask */

     GRALLOC_USAGE_HW_MASK         = 0x00001F00,

 };

 /*****************************************************************************/

 typedef const native_handle* buffer_handle_t;

 enum {

     /* FIXME: this only exists to work-around some issues with

      * the video and camera frameworks. don't implement unless

      * you know what you're doing.

      */

     GRALLOC_MODULE_PERFORM_CREATE_HANDLE_FROM_BUFFER = 0x080000001,

 };

 /**

  * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM

  * and the fields of this data structure must begin with hw_module_t

  * followed by module specific information.

  */

 typedef struct gralloc_module_t {

     struct hw_module_t common;

     /*

      * (*registerBuffer)() must be called before a buffer_handle_t that has not

      * been created with (*alloc_device_t::alloc)() can be used.

      * 

      * This is intended to be used with buffer_handle_t's that have been

      * received in this process through IPC.

      * 

      * This function checks that the handle is indeed a valid one and prepares

      * it for use with (*lock)() and (*unlock)().

      * 

      * It is not necessary to call (*registerBuffer)() on a handle created 

      * with (*alloc_device_t::alloc)().

      * 

      * returns an error if this buffer_handle_t is not valid.

      */

     int (*registerBuffer)(struct gralloc_module_t const* module,

             buffer_handle_t handle);

     /*

      * (*unregisterBuffer)() is called once this handle is no longer needed in

      * this process. After this call, it is an error to call (*lock)(),

      * (*unlock)(), or (*registerBuffer)().

      * 

      * This function doesn't close or free the handle itself; this is done

      * by other means, usually through libcutils's native_handle_close() and

      * native_handle_free(). 

      * 

      * It is an error to call (*unregisterBuffer)() on a buffer that wasn't

      * explicitly registered first.

      */

     int (*unregisterBuffer)(struct gralloc_module_t const* module,

             buffer_handle_t handle);

     /*

      * The (*lock)() method is called before a buffer is accessed for the 

      * specified usage. This call may block, for instance if the h/w needs

      * to finish rendering or if CPU caches need to be synchronized.

      * 

      * The caller promises to modify only pixels in the area specified 

      * by (l,t,w,h).

      * 

      * The content of the buffer outside of the specified area is NOT modified

      * by this call.

      *

      * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address

      * of the buffer in virtual memory.

      *

      * THREADING CONSIDERATIONS:

      *

      * It is legal for several different threads to lock a buffer from 

      * read access, none of the threads are blocked.

      * 

      * However, locking a buffer simultaneously for write or read/write is

      * undefined, but:

      * - shall not result in termination of the process

      * - shall not block the caller

      * It is acceptable to return an error or to leave the buffer's content

      * into an indeterminate state.

      *

      * If the buffer was created with a usage mask incompatible with the

      * requested usage flags here, -EINVAL is returned. 

      * 

      */

     int (*lock)(struct gralloc_module_t const* module,

             buffer_handle_t handle, int usage,

             int l, int t, int w, int h,

             void** vaddr);

     /*

      * The (*unlock)() method must be called after all changes to the buffer

      * are completed.

      */

     int (*unlock)(struct gralloc_module_t const* module,

             buffer_handle_t handle);

     /* reserved for future use */

     int (*perform)(struct gralloc_module_t const* module,

             int operation, ... );

     /* reserved for future use */

     void* reserved_proc[7];

 } gralloc_module_t;

 /*****************************************************************************/

 /**

  * Every device data structure must begin with hw_device_t

  * followed by module specific public methods and attributes.

  */

 typedef struct alloc_device_t {

     struct hw_device_t common;

     /* 

      * (*alloc)() Allocates a buffer in graphic memory with the requested

      * parameters and returns a buffer_handle_t and the stride in pixels to

      * allow the implementation to satisfy hardware constraints on the width

      * of a pixmap (eg: it may have to be multiple of 8 pixels). 

      * The CALLER TAKES OWNERSHIP of the buffer_handle_t.

      * 

      * Returns 0 on success or -errno on error.

      */

     int (*alloc)(struct alloc_device_t* dev,

             int w, int h, int format, int usage,

             buffer_handle_t* handle, int* stride);

     /*

      * (*free)() Frees a previously allocated buffer. 

      * Behavior is undefined if the buffer is still mapped in any process,

      * but shall not result in termination of the program or security breaches

      * (allowing a process to get access to another process' buffers).

      * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes

      * invalid after the call. 

      * 

      * Returns 0 on success or -errno on error.

      */

     int (*free)(struct alloc_device_t* dev,

             buffer_handle_t handle);

 } alloc_device_t;

 typedef struct framebuffer_device_t {

     struct hw_device_t common;

     /* flags describing some attributes of the framebuffer */

     const uint32_t  flags;

     /* dimensions of the framebuffer in pixels */

     const uint32_t  width;

     const uint32_t  height;

     /* frambuffer stride in pixels */

     const int       stride;

     /* framebuffer pixel format */

     const int       format;

     /* resolution of the framebuffer's display panel in pixel per inch*/

     const float     xdpi;

     const float     ydpi;

     /* framebuffer's display panel refresh rate in frames per second */

     const float     fps;

     /* min swap interval supported by this framebuffer */

     const int       minSwapInterval;

     /* max swap interval supported by this framebuffer */

     const int       maxSwapInterval;

     int reserved[8];

     /* 

      * requests a specific swap-interval (same definition than EGL) 

      * 

      * Returns 0 on success or -errno on error.

      */

     int (*setSwapInterval)(struct framebuffer_device_t* window,

             int interval);

     /*

      * This hook is OPTIONAL.

      * 

      * It is non NULL If the framebuffer driver supports "update-on-demand" 

      * and the given rectangle is the area of the screen that gets 

      * updated during (*post)().

      * 

      * This is useful on devices that are able to DMA only a portion of

      * the screen to the display panel, upon demand -- as opposed to

      * constantly refreshing the panel 60 times per second, for instance.

      * 

      * Only the area defined by this rectangle is guaranteed to be valid, that

      * is, the driver is not allowed to post anything outside of this

      * rectangle. 

      * 

      * The rectangle evaluated during (*post)() and specifies which area

      * of the buffer passed in (*post)() shall to be posted.

      * 

      * return -EINVAL if width or height <=0, or if left or top < 0 

      */

     int (*setUpdateRect)(struct framebuffer_device_t* window,

             int left, int top, int width, int height);

     /*

      * Post <buffer> to the display (display it on the screen)

      * The buffer must have been allocated with the 

      *   GRALLOC_USAGE_HW_FB usage flag.

      * buffer must be the same width and height as the display and must NOT

      * be locked.

      * 

      * The buffer is shown during the next VSYNC. 

      * 

      * If the same buffer is posted again (possibly after some other buffer),

      * post() will block until the the first post is completed.

      *

      * Internally, post() is expected to lock the buffer so that a 

      * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or

      * USAGE_*_WRITE will block until it is safe; that is typically once this

      * buffer is shown and another buffer has been posted.

      *

      * Returns 0 on success or -errno on error.

      */

     int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);

     /*

      * The (*compositionComplete)() method must be called after the

      * compositor has finished issuing GL commands for client buffers.

      */

     int (*compositionComplete)(struct framebuffer_device_t* dev);

     void* reserved_proc[8];

 } framebuffer_device_t;

 /** convenience API for opening and closing a supported device */

 static inline int gralloc_open(const struct hw_module_t* module, 

         struct alloc_device_t** device) {

     return module->methods->open(module, 

             GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);

 }

 static inline int gralloc_close(struct alloc_device_t* device) {

     return device->common.close(&device->common);

 }

 static inline int framebuffer_open(const struct hw_module_t* module, 

         struct framebuffer_device_t** device) {

     return module->methods->open(module, 

             GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);

 }

 static inline int framebuffer_close(struct framebuffer_device_t* device) {

     return device->common.close(&device->common);

 }

 __END_DECLS

 #endif  // ANDROID_ALLOC_INTERFACE_H