hardware/fb.h

   1 /*
   2  * Copyright (C) 2008 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
  18 #ifndef ANDROID_FB_INTERFACE_H
  19 #define ANDROID_FB_INTERFACE_H
  20
  21 #include <stdint.h>
  22 #include <sys/cdefs.h>
  23 #include <sys/types.h>
  24
  25 #include <cutils/native_handle.h>
  26
  27 #include <hardware/hardware.h>
  28
  29 __BEGIN_DECLS
  30
  31 #define GRALLOC_HARDWARE_FB0 "fb0"
  32
  33 /*****************************************************************************/
  34
  35
  36 /*****************************************************************************/
  37
  38 typedef struct framebuffer_device_t {
  39     struct hw_device_t common;
  40
  41     /* flags describing some attributes of the framebuffer */
  42     const uint32_t  flags;
  43
  44     /* dimensions of the framebuffer in pixels */
  45     const uint32_t  width;
  46     const uint32_t  height;
  47
  48     /* frambuffer stride in pixels */
  49     const int       stride;
  50
  51     /* framebuffer pixel format */
  52     const int       format;
  53
  54     /* resolution of the framebuffer's display panel in pixel per inch*/
  55     const float     xdpi;
  56     const float     ydpi;
  57
  58     /* framebuffer's display panel refresh rate in frames per second */
  59     const float     fps;
  60
  61     /* min swap interval supported by this framebuffer */
  62     const int       minSwapInterval;
  63
  64     /* max swap interval supported by this framebuffer */
  65     const int       maxSwapInterval;
  66
  67     /* Number of framebuffers supported*/
  68     const int       numFramebuffers;
  69
  70     int reserved[7];
  71
  72     /*
  73      * requests a specific swap-interval (same definition than EGL)
  74      *
  75      * Returns 0 on success or -errno on error.
  76      */
  77     int (*setSwapInterval)(struct framebuffer_device_t* window,
  78             int interval);
  79
  80     /*
  81      * This hook is OPTIONAL.
  82      *
  83      * It is non NULL If the framebuffer driver supports "update-on-demand"
  84      * and the given rectangle is the area of the screen that gets
  85      * updated during (*post)().
  86      *
  87      * This is useful on devices that are able to DMA only a portion of
  88      * the screen to the display panel, upon demand -- as opposed to
  89      * constantly refreshing the panel 60 times per second, for instance.
  90      *
  91      * Only the area defined by this rectangle is guaranteed to be valid, that
  92      * is, the driver is not allowed to post anything outside of this
  93      * rectangle.
  94      *
  95      * The rectangle evaluated during (*post)() and specifies which area
  96      * of the buffer passed in (*post)() shall to be posted.
  97      *
  98      * return -EINVAL if width or height <=0, or if left or top < 0
  99      */
 100     int (*setUpdateRect)(struct framebuffer_device_t* window,
 101             int left, int top, int width, int height);
 102
 103     /*
 104      * Post <buffer> to the display (display it on the screen)
 105      * The buffer must have been allocated with the
 106      *   GRALLOC_USAGE_HW_FB usage flag.
 107      * buffer must be the same width and height as the display and must NOT
 108      * be locked.
 109      *
 110      * The buffer is shown during the next VSYNC.
 111      *
 112      * If the same buffer is posted again (possibly after some other buffer),
 113      * post() will block until the the first post is completed.
 114      *
 115      * Internally, post() is expected to lock the buffer so that a
 116      * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
 117      * USAGE_*_WRITE will block until it is safe; that is typically once this
 118      * buffer is shown and another buffer has been posted.
 119      *
 120      * Returns 0 on success or -errno on error.
 121      */
 122     int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
 123
 124
 125     /*
 126      * The (*compositionComplete)() method must be called after the
 127      * compositor has finished issuing GL commands for client buffers.
 128      */
 129
 130     int (*compositionComplete)(struct framebuffer_device_t* dev);
 131
 132     /*
 133      * This hook is OPTIONAL.
 134      *
 135      * If non NULL it will be caused by SurfaceFlinger on dumpsys
 136      */
 137     void (*dump)(struct framebuffer_device_t* dev, char *buff, int buff_len);
 138
 139     /*
 140      * (*enableScreen)() is used to either blank (enable=0) or
 141      * unblank (enable=1) the screen this framebuffer is attached to.
 142      *
 143      * Returns 0 on success or -errno on error.
 144      */
 145     int (*enableScreen)(struct framebuffer_device_t* dev, int enable);
 146
 147     void* reserved_proc[6];
 148
 149 } framebuffer_device_t;
 150
 151
 152 /** convenience API for opening and closing a supported device */
 153
 154 static inline int framebuffer_open(const struct hw_module_t* module,
 155         struct framebuffer_device_t** device) {
 156     return module->methods->open(module,
 157             GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
 158 }
 159
 160 static inline int framebuffer_close(struct framebuffer_device_t* device) {
 161     return device->common.close(&device->common);
 162 }
 163
 164
 165 __END_DECLS
 166
 167 #endif  // ANDROID_FB_INTERFACE_H