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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_GRALLOC_INTERFACE_H
     19 #define ANDROID_GRALLOC_INTERFACE_H
     20 
     21 #include <system/window.h>
     22 #include <hardware/hardware.h>
     23 
     24 #include <stdint.h>
     25 #include <sys/cdefs.h>
     26 #include <sys/types.h>
     27 
     28 #include <cutils/native_handle.h>
     29 
     30 #include <hardware/hardware.h>
     31 #include <hardware/fb.h>
     32 
     33 __BEGIN_DECLS
     34 
     35 #define GRALLOC_API_VERSION 1
     36 
     37 /**
     38  * The id of this module
     39  */
     40 #define GRALLOC_HARDWARE_MODULE_ID "gralloc"
     41 
     42 /**
     43  * Name of the graphics device to open
     44  */
     45 
     46 #define GRALLOC_HARDWARE_GPU0 "gpu0"
     47 
     48 enum {
     49     /* buffer is never read in software */
     50     GRALLOC_USAGE_SW_READ_NEVER   = 0x00000000,
     51     /* buffer is rarely read in software */
     52     GRALLOC_USAGE_SW_READ_RARELY  = 0x00000002,
     53     /* buffer is often read in software */
     54     GRALLOC_USAGE_SW_READ_OFTEN   = 0x00000003,
     55     /* mask for the software read values */
     56     GRALLOC_USAGE_SW_READ_MASK    = 0x0000000F,
     57 
     58     /* buffer is never written in software */
     59     GRALLOC_USAGE_SW_WRITE_NEVER  = 0x00000000,
     60     /* buffer is never written in software */
     61     GRALLOC_USAGE_SW_WRITE_RARELY = 0x00000020,
     62     /* buffer is never written in software */
     63     GRALLOC_USAGE_SW_WRITE_OFTEN  = 0x00000030,
     64     /* mask for the software write values */
     65     GRALLOC_USAGE_SW_WRITE_MASK   = 0x000000F0,
     66 
     67     /* buffer will be used as an OpenGL ES texture */
     68     GRALLOC_USAGE_HW_TEXTURE      = 0x00000100,
     69     /* buffer will be used as an OpenGL ES render target */
     70     GRALLOC_USAGE_HW_RENDER       = 0x00000200,
     71     /* buffer will be used by the 2D hardware blitter */
     72     GRALLOC_USAGE_HW_2D           = 0x00000400,
     73     /* buffer will be used by the HWComposer HAL module */
     74     GRALLOC_USAGE_HW_COMPOSER     = 0x00000800,
     75     /* buffer will be used with the framebuffer device */
     76     GRALLOC_USAGE_HW_FB           = 0x00001000,
     77     /* mask for the software usage bit-mask */
     78     GRALLOC_USAGE_HW_MASK         = 0x00001F00,
     79 
     80     /* buffer should be displayed full-screen on an external display when
     81      * possible
     82      */
     83     GRALLOC_USAGE_EXTERNAL_DISP   = 0x00002000,
     84 
     85     /* Must have a hardware-protected path to external display sink for
     86      * this buffer.  If a hardware-protected path is not available, then
     87      * either don't composite only this buffer (preferred) to the
     88      * external sink, or (less desirable) do not route the entire
     89      * composition to the external sink.
     90      */
     91     GRALLOC_USAGE_PROTECTED       = 0x00004000,
     92 
     93     /* implementation-specific private usage flags */
     94     GRALLOC_USAGE_PRIVATE_0       = 0x10000000,
     95     GRALLOC_USAGE_PRIVATE_1       = 0x20000000,
     96     GRALLOC_USAGE_PRIVATE_2       = 0x40000000,
     97     GRALLOC_USAGE_PRIVATE_3       = 0x80000000,
     98     GRALLOC_USAGE_PRIVATE_MASK    = 0xF0000000,
     99 };
    100 
    101 /*****************************************************************************/
    102 
    103 /**
    104  * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
    105  * and the fields of this data structure must begin with hw_module_t
    106  * followed by module specific information.
    107  */
    108 typedef struct gralloc_module_t {
    109     struct hw_module_t common;
    110 
    111     /*
    112      * (*registerBuffer)() must be called before a buffer_handle_t that has not
    113      * been created with (*alloc_device_t::alloc)() can be used.
    114      *
    115      * This is intended to be used with buffer_handle_t's that have been
    116      * received in this process through IPC.
    117      *
    118      * This function checks that the handle is indeed a valid one and prepares
    119      * it for use with (*lock)() and (*unlock)().
    120      *
    121      * It is not necessary to call (*registerBuffer)() on a handle created
    122      * with (*alloc_device_t::alloc)().
    123      *
    124      * returns an error if this buffer_handle_t is not valid.
    125      */
    126     int (*registerBuffer)(struct gralloc_module_t const* module,
    127             buffer_handle_t handle);
    128 
    129     /*
    130      * (*unregisterBuffer)() is called once this handle is no longer needed in
    131      * this process. After this call, it is an error to call (*lock)(),
    132      * (*unlock)(), or (*registerBuffer)().
    133      *
    134      * This function doesn't close or free the handle itself; this is done
    135      * by other means, usually through libcutils's native_handle_close() and
    136      * native_handle_free().
    137      *
    138      * It is an error to call (*unregisterBuffer)() on a buffer that wasn't
    139      * explicitly registered first.
    140      */
    141     int (*unregisterBuffer)(struct gralloc_module_t const* module,
    142             buffer_handle_t handle);
    143 
    144     /*
    145      * The (*lock)() method is called before a buffer is accessed for the
    146      * specified usage. This call may block, for instance if the h/w needs
    147      * to finish rendering or if CPU caches need to be synchronized.
    148      *
    149      * The caller promises to modify only pixels in the area specified
    150      * by (l,t,w,h).
    151      *
    152      * The content of the buffer outside of the specified area is NOT modified
    153      * by this call.
    154      *
    155      * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address
    156      * of the buffer in virtual memory.
    157      *
    158      * THREADING CONSIDERATIONS:
    159      *
    160      * It is legal for several different threads to lock a buffer from
    161      * read access, none of the threads are blocked.
    162      *
    163      * However, locking a buffer simultaneously for write or read/write is
    164      * undefined, but:
    165      * - shall not result in termination of the process
    166      * - shall not block the caller
    167      * It is acceptable to return an error or to leave the buffer's content
    168      * into an indeterminate state.
    169      *
    170      * If the buffer was created with a usage mask incompatible with the
    171      * requested usage flags here, -EINVAL is returned.
    172      *
    173      */
    174 
    175     int (*lock)(struct gralloc_module_t const* module,
    176             buffer_handle_t handle, int usage,
    177             int l, int t, int w, int h,
    178             void** vaddr);
    179 
    180 
    181     /*
    182      * The (*unlock)() method must be called after all changes to the buffer
    183      * are completed.
    184      */
    185 
    186     int (*unlock)(struct gralloc_module_t const* module,
    187             buffer_handle_t handle);
    188 
    189 
    190     /* reserved for future use */
    191     int (*perform)(struct gralloc_module_t const* module,
    192             int operation, ... );
    193 
    194     /* reserved for future use */
    195     void* reserved_proc[7];
    196 } gralloc_module_t;
    197 
    198 /*****************************************************************************/
    199 
    200 /**
    201  * Every device data structure must begin with hw_device_t
    202  * followed by module specific public methods and attributes.
    203  */
    204 
    205 typedef struct alloc_device_t {
    206     struct hw_device_t common;
    207 
    208     /*
    209      * (*alloc)() Allocates a buffer in graphic memory with the requested
    210      * parameters and returns a buffer_handle_t and the stride in pixels to
    211      * allow the implementation to satisfy hardware constraints on the width
    212      * of a pixmap (eg: it may have to be multiple of 8 pixels).
    213      * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
    214      *
    215      * Returns 0 on success or -errno on error.
    216      */
    217 
    218     int (*alloc)(struct alloc_device_t* dev,
    219             int w, int h, int format, int usage,
    220             buffer_handle_t* handle, int* stride);
    221 
    222     /*
    223      * (*free)() Frees a previously allocated buffer.
    224      * Behavior is undefined if the buffer is still mapped in any process,
    225      * but shall not result in termination of the program or security breaches
    226      * (allowing a process to get access to another process' buffers).
    227      * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
    228      * invalid after the call.
    229      *
    230      * Returns 0 on success or -errno on error.
    231      */
    232     int (*free)(struct alloc_device_t* dev,
    233             buffer_handle_t handle);
    234 
    235     /* This hook is OPTIONAL.
    236      *
    237      * If non NULL it will be caused by SurfaceFlinger on dumpsys
    238      */
    239     void (*dump)(struct alloc_device_t *dev, char *buff, int buff_len);
    240 
    241     void* reserved_proc[7];
    242 } alloc_device_t;
    243 
    244 
    245 /** convenience API for opening and closing a supported device */
    246 
    247 static inline int gralloc_open(const struct hw_module_t* module,
    248         struct alloc_device_t** device) {
    249     return module->methods->open(module,
    250             GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
    251 }
    252 
    253 static inline int gralloc_close(struct alloc_device_t* device) {
    254     return device->common.close(&device->common);
    255 }
    256 
    257 __END_DECLS
    258 
    259 #endif  // ANDROID_ALLOC_INTERFACE_H
    260