text: /*
   * 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 <android/system/window.h>
  #include <android/hardware/hardware.h>
  
  #include <stdint.h>
  #include <sys/cdefs.h>
  #include <sys/types.h>
  
  #include <android/cutils/native_handle.h>
  
  #include <android/hardware/hardware.h>
  #include <android/hardware/fb.h>
  
  __BEGIN_DECLS
  
  #define GRALLOC_API_VERSION 1
  
  /**
   * The id of this module
   */
  #define GRALLOC_HARDWARE_MODULE_ID "gralloc"
  
  /**
   * Name of the graphics device to open
   */
  
  #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                 = 0x00000400,
      /* buffer will be used by the HWComposer HAL module */
      GRALLOC_USAGE_HW_COMPOSER           = 0x00000800,
      /* buffer will be used with the framebuffer device */
      GRALLOC_USAGE_HW_FB                 = 0x00001000,
      /* buffer will be used with the HW video encoder */
      GRALLOC_USAGE_HW_VIDEO_ENCODER      = 0x00010000,
      /* mask for the software usage bit-mask */
      GRALLOC_USAGE_HW_MASK               = 0x00011F00,
  
      /* buffer should be displayed full-screen on an external display when
       * possible
       */
      GRALLOC_USAGE_EXTERNAL_DISP         = 0x00002000,
  
      /* Must have a hardware-protected path to external display sink for
       * this buffer.  If a hardware-protected path is not available, then
       * either don't composite only this buffer (preferred) to the
       * external sink, or (less desirable) do not route the entire
       * composition to the external sink.
       */
      GRALLOC_USAGE_PROTECTED             = 0x00004000,
  
      /* implementation-specific private usage flags */
      GRALLOC_USAGE_PRIVATE_0             = 0x10000000,
      GRALLOC_USAGE_PRIVATE_1             = 0x20000000,
      GRALLOC_USAGE_PRIVATE_2             = 0x40000000,
      GRALLOC_USAGE_PRIVATE_3             = 0x80000000,
      GRALLOC_USAGE_PRIVATE_MASK          = 0xF0000000,
  };
  
  /*****************************************************************************/
  
  /**
   * 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);
  
      /* This hook is OPTIONAL.
       *
       * If non NULL it will be caused by SurfaceFlinger on dumpsys
       */
      void (*dump)(struct alloc_device_t *dev, char *buff, int buff_len);
  
      void* reserved_proc[7];
  } alloc_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);
  }
  
  __END_DECLS
  
  #endif  // ANDROID_GRALLOC_INTERFACE_H
  