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      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     /**
     40      * Common methods of the framebuffer device.  This *must* be the first member of
     41      * framebuffer_device_t as users of this structure will cast a hw_device_t to
     42      * framebuffer_device_t pointer in contexts where it's known the hw_device_t references a
     43      * framebuffer_device_t.
     44      */
     45     struct hw_device_t common;
     46 
     47     /* flags describing some attributes of the framebuffer */
     48     const uint32_t  flags;
     49 
     50     /* dimensions of the framebuffer in pixels */
     51     const uint32_t  width;
     52     const uint32_t  height;
     53 
     54     /* frambuffer stride in pixels */
     55     const int       stride;
     56 
     57     /* framebuffer pixel format */
     58     const int       format;
     59 
     60     /* resolution of the framebuffer's display panel in pixel per inch*/
     61     const float     xdpi;
     62     const float     ydpi;
     63 
     64     /* framebuffer's display panel refresh rate in frames per second */
     65     const float     fps;
     66 
     67     /* min swap interval supported by this framebuffer */
     68     const int       minSwapInterval;
     69 
     70     /* max swap interval supported by this framebuffer */
     71     const int       maxSwapInterval;
     72 
     73     /* Number of framebuffers supported*/
     74     const int       numFramebuffers;
     75 
     76     int reserved[7];
     77 
     78     /*
     79      * requests a specific swap-interval (same definition than EGL)
     80      *
     81      * Returns 0 on success or -errno on error.
     82      */
     83     int (*setSwapInterval)(struct framebuffer_device_t* window,
     84             int interval);
     85 
     86     /*
     87      * This hook is OPTIONAL.
     88      *
     89      * It is non NULL If the framebuffer driver supports "update-on-demand"
     90      * and the given rectangle is the area of the screen that gets
     91      * updated during (*post)().
     92      *
     93      * This is useful on devices that are able to DMA only a portion of
     94      * the screen to the display panel, upon demand -- as opposed to
     95      * constantly refreshing the panel 60 times per second, for instance.
     96      *
     97      * Only the area defined by this rectangle is guaranteed to be valid, that
     98      * is, the driver is not allowed to post anything outside of this
     99      * rectangle.
    100      *
    101      * The rectangle evaluated during (*post)() and specifies which area
    102      * of the buffer passed in (*post)() shall to be posted.
    103      *
    104      * return -EINVAL if width or height <=0, or if left or top < 0
    105      */
    106     int (*setUpdateRect)(struct framebuffer_device_t* window,
    107             int left, int top, int width, int height);
    108 
    109     /*
    110      * Post <buffer> to the display (display it on the screen)
    111      * The buffer must have been allocated with the
    112      *   GRALLOC_USAGE_HW_FB usage flag.
    113      * buffer must be the same width and height as the display and must NOT
    114      * be locked.
    115      *
    116      * The buffer is shown during the next VSYNC.
    117      *
    118      * If the same buffer is posted again (possibly after some other buffer),
    119      * post() will block until the the first post is completed.
    120      *
    121      * Internally, post() is expected to lock the buffer so that a
    122      * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
    123      * USAGE_*_WRITE will block until it is safe; that is typically once this
    124      * buffer is shown and another buffer has been posted.
    125      *
    126      * Returns 0 on success or -errno on error.
    127      */
    128     int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
    129 
    130 
    131     /*
    132      * The (*compositionComplete)() method must be called after the
    133      * compositor has finished issuing GL commands for client buffers.
    134      */
    135 
    136     int (*compositionComplete)(struct framebuffer_device_t* dev);
    137 
    138     /*
    139      * This hook is OPTIONAL.
    140      *
    141      * If non NULL it will be caused by SurfaceFlinger on dumpsys
    142      */
    143     void (*dump)(struct framebuffer_device_t* dev, char *buff, int buff_len);
    144 
    145     /*
    146      * (*enableScreen)() is used to either blank (enable=0) or
    147      * unblank (enable=1) the screen this framebuffer is attached to.
    148      *
    149      * Returns 0 on success or -errno on error.
    150      */
    151     int (*enableScreen)(struct framebuffer_device_t* dev, int enable);
    152 
    153     void* reserved_proc[6];
    154 
    155 } framebuffer_device_t;
    156 
    157 
    158 /** convenience API for opening and closing a supported device */
    159 
    160 static inline int framebuffer_open(const struct hw_module_t* module,
    161         struct framebuffer_device_t** device) {
    162     return module->methods->open(module,
    163             GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
    164 }
    165 
    166 static inline int framebuffer_close(struct framebuffer_device_t* device) {
    167     return device->common.close(&device->common);
    168 }
    169 
    170 
    171 __END_DECLS
    172 
    173 #endif  // ANDROID_FB_INTERFACE_H
    174