gralloc.h revision 8255d9d3b62ddf90269ddbb54e6f92b29908fa75
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 <cutils/native_handle.h> 22 23#include <hardware/hardware.h> 24 25#include <stdint.h> 26#include <sys/cdefs.h> 27#include <sys/types.h> 28 29__BEGIN_DECLS 30 31/** 32 * The id of this module 33 */ 34#define GRALLOC_HARDWARE_MODULE_ID "gralloc" 35 36/** 37 * Name of the graphics device to open 38 */ 39 40#define GRALLOC_HARDWARE_FB0 "fb0" 41#define GRALLOC_HARDWARE_GPU0 "gpu0" 42 43enum { 44 /* buffer is never read in software */ 45 GRALLOC_USAGE_SW_READ_NEVER = 0x00000000, 46 /* buffer is rarely read in software */ 47 GRALLOC_USAGE_SW_READ_RARELY = 0x00000002, 48 /* buffer is often read in software */ 49 GRALLOC_USAGE_SW_READ_OFTEN = 0x00000003, 50 /* mask for the software read values */ 51 GRALLOC_USAGE_SW_READ_MASK = 0x0000000F, 52 53 /* buffer is never written in software */ 54 GRALLOC_USAGE_SW_WRITE_NEVER = 0x00000000, 55 /* buffer is never written in software */ 56 GRALLOC_USAGE_SW_WRITE_RARELY = 0x00000020, 57 /* buffer is never written in software */ 58 GRALLOC_USAGE_SW_WRITE_OFTEN = 0x00000030, 59 /* mask for the software write values */ 60 GRALLOC_USAGE_SW_WRITE_MASK = 0x000000F0, 61 62 /* buffer will be used as an OpenGL ES texture */ 63 GRALLOC_USAGE_HW_TEXTURE = 0x00000100, 64 /* buffer will be used as an OpenGL ES render target */ 65 GRALLOC_USAGE_HW_RENDER = 0x00000200, 66 /* buffer will be used by the 2D hardware blitter */ 67 GRALLOC_USAGE_HW_2D = 0x00000C00, 68 /* buffer will be used with the framebuffer device */ 69 GRALLOC_USAGE_HW_FB = 0x00001000, 70 /* mask for the software usage bit-mask */ 71 GRALLOC_USAGE_HW_MASK = 0x00001F00, 72}; 73 74/*****************************************************************************/ 75 76typedef const native_handle* buffer_handle_t; 77 78/** 79 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 80 * and the fields of this data structure must begin with hw_module_t 81 * followed by module specific information. 82 */ 83typedef struct gralloc_module_t { 84 struct hw_module_t common; 85 86 87 /* 88 * (*registerBuffer)() must be called before a buffer_handle_t that has not 89 * been created with (*alloc_device_t::alloc)() can be used. 90 * 91 * This is intended to be used with buffer_handle_t's that have been 92 * received in this process through IPC. 93 * 94 * This function checks that the handle is indeed a valid one and prepares 95 * it for use with (*lock)() and (*unlock)(). 96 * 97 * It is not necessary to call (*registerBuffer)() on a handle created 98 * with (*alloc_device_t::alloc)(). 99 * 100 * returns an error if this buffer_handle_t is not valid. 101 */ 102 int (*registerBuffer)(struct gralloc_module_t const* module, 103 buffer_handle_t handle); 104 105 /* 106 * (*unregisterBuffer)() is called once this handle is no longer needed in 107 * this process. After this call, it is an error to call (*lock)(), 108 * (*unlock)(), or (*registerBuffer)(). 109 * 110 * This function doesn't close or free the handle itself; this is done 111 * by other means, usually through libcutils's native_handle_close() and 112 * native_handle_free(). 113 * 114 * It is an error to call (*unregisterBuffer)() on a buffer that wasn't 115 * explicitly registered first. 116 */ 117 int (*unregisterBuffer)(struct gralloc_module_t const* module, 118 buffer_handle_t handle); 119 120 /* 121 * The (*lock)() method is called before a buffer is accessed for the 122 * specified usage. This call may block, for instance if the h/w needs 123 * to finish rendering or if CPU caches need to be synchronized. 124 * 125 * The caller promises to modify only pixels in the area specified 126 * by (l,t,w,h). 127 * 128 * The content of the buffer outside of the specified area is NOT modified 129 * by this call. 130 * 131 * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address 132 * of the buffer in virtual memory. 133 * 134 * THREADING CONSIDERATIONS: 135 * 136 * It is legal for several different threads to lock a buffer from 137 * read access, none of the threads are blocked. 138 * 139 * However, locking a buffer simultaneously for write or read/write is 140 * undefined, but: 141 * - shall not result in termination of the process 142 * - shall not block the caller 143 * It is acceptable to return an error or to leave the buffer's content 144 * into an indeterminate state. 145 * 146 * If the buffer was created with a usage mask incompatible with the 147 * requested usage flags here, -EINVAL is returned. 148 * 149 */ 150 151 int (*lock)(struct gralloc_module_t const* module, 152 buffer_handle_t handle, int usage, 153 int l, int t, int w, int h, 154 void** vaddr); 155 156 157 /* 158 * The (*unlock)() method must be called after all changes to the buffer 159 * are completed. 160 */ 161 162 int (*unlock)(struct gralloc_module_t const* module, 163 buffer_handle_t handle); 164 165 /* reserved for future use */ 166 void* reserved_proc[8]; 167} gralloc_module_t; 168 169/*****************************************************************************/ 170 171/** 172 * Every device data structure must begin with hw_device_t 173 * followed by module specific public methods and attributes. 174 */ 175 176typedef struct alloc_device_t { 177 struct hw_device_t common; 178 179 /* 180 * (*alloc)() Allocates a buffer in graphic memory with the requested 181 * parameters and returns a buffer_handle_t and the stride in pixels to 182 * allow the implementation to satisfy hardware constraints on the width 183 * of a pixmap (eg: it may have to be multiple of 8 pixels). 184 * The CALLER TAKES OWNERSHIP of the buffer_handle_t. 185 * 186 * Returns 0 on success or -errno on error. 187 */ 188 189 int (*alloc)(struct alloc_device_t* dev, 190 int w, int h, int format, int usage, 191 buffer_handle_t* handle, int* stride); 192 193 /* 194 * (*free)() Frees a previously allocated buffer. 195 * Behavior is undefined if the buffer is still mapped in any process, 196 * but shall not result in termination of the program or security breaches 197 * (allowing a process to get access to another process' buffers). 198 * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes 199 * invalid after the call. 200 * 201 * Returns 0 on success or -errno on error. 202 */ 203 int (*free)(struct alloc_device_t* dev, 204 buffer_handle_t handle); 205 206} alloc_device_t; 207 208 209typedef struct framebuffer_device_t { 210 struct hw_device_t common; 211 212 /* flags describing some attributes of the framebuffer */ 213 const uint32_t flags; 214 215 /* dimensions of the framebuffer in pixels */ 216 const uint32_t width; 217 const uint32_t height; 218 219 /* frambuffer stride in pixels */ 220 const int stride; 221 222 /* framebuffer pixel format */ 223 const int format; 224 225 /* resolution of the framebuffer's display panel in pixel per inch*/ 226 const float xdpi; 227 const float ydpi; 228 229 /* framebuffer's display panel refresh rate in frames per second */ 230 const float fps; 231 232 /* min swap interval supported by this framebuffer */ 233 const int minSwapInterval; 234 235 /* max swap interval supported by this framebuffer */ 236 const int maxSwapInterval; 237 238 int reserved[8]; 239 240 /* 241 * requests a specific swap-interval (same definition than EGL) 242 * 243 * Returns 0 on success or -errno on error. 244 */ 245 int (*setSwapInterval)(struct framebuffer_device_t* window, 246 int interval); 247 248 /* 249 * This hook is OPTIONAL. 250 * 251 * It is non NULL If the framebuffer driver supports "update-on-demand" 252 * and the given rectangle is the area of the screen that gets 253 * updated during (*post)(). 254 * 255 * This is useful on devices that are able to DMA only a portion of 256 * the screen to the display panel, upon demand -- as opposed to 257 * constantly refreshing the panel 60 times per second, for instance. 258 * 259 * Only the area defined by this rectangle is guaranteed to be valid, that 260 * is, the driver is not allowed to post anything outside of this 261 * rectangle. 262 * 263 * The rectangle evaluated during (*post)() and specifies which area 264 * of the buffer passed in (*post)() shall to be posted. 265 * 266 * return -EINVAL if width or height <=0, or if left or top < 0 267 */ 268 int (*setUpdateRect)(struct framebuffer_device_t* window, 269 int left, int top, int width, int height); 270 271 /* 272 * Post <buffer> to the display (display it on the screen) 273 * The buffer must have been allocated with the 274 * GRALLOC_USAGE_HW_FB usage flag. 275 * buffer must be the same width and height as the display and must NOT 276 * be locked. 277 * 278 * The buffer is shown during the next VSYNC. 279 * 280 * If the same buffer is posted again (possibly after some other buffer), 281 * post() will block until the the first post is completed. 282 * 283 * Internally, post() is expected to lock the buffer so that a 284 * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or 285 * USAGE_*_WRITE will block until it is safe; that is typically once this 286 * buffer is shown and another buffer has been posted. 287 * 288 * Returns 0 on success or -errno on error. 289 */ 290 int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer); 291 292 293 /* 294 * The (*compositionComplete)() method must be called after the 295 * compositor has finished issuing GL commands for client buffers. 296 */ 297 298 int (*compositionComplete)(struct framebuffer_device_t* dev); 299 300 301 void* reserved_proc[8]; 302 303} framebuffer_device_t; 304 305 306/** convenience API for opening and closing a supported device */ 307 308static inline int gralloc_open(const struct hw_module_t* module, 309 struct alloc_device_t** device) { 310 return module->methods->open(module, 311 GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device); 312} 313 314static inline int gralloc_close(struct alloc_device_t* device) { 315 return device->common.close(&device->common); 316} 317 318 319static inline int framebuffer_open(const struct hw_module_t* module, 320 struct framebuffer_device_t** device) { 321 return module->methods->open(module, 322 GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device); 323} 324 325static inline int framebuffer_close(struct framebuffer_device_t* device) { 326 return device->common.close(&device->common); 327} 328 329 330__END_DECLS 331 332#endif // ANDROID_ALLOC_INTERFACE_H 333