gralloc.h revision cd2433f3804a537aedc26f595b1c05f95a05244a 
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
78enum {
79    /* FIXME: this only exists to work-around some issues with
80     * the video and camera frameworks. don't implement unless
81     * you know what you're doing.
82     */
83    GRALLOC_MODULE_PERFORM_CREATE_HANDLE_FROM_BUFFER = 0x080000001,
84};
85
86/**
87 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
88 * and the fields of this data structure must begin with hw_module_t
89 * followed by module specific information.
90 */
91typedef struct gralloc_module_t {
92    struct hw_module_t common;
93
94    /*
95     * (*registerBuffer)() must be called before a buffer_handle_t that has not
96     * been created with (*alloc_device_t::alloc)() can be used.
97     *
98     * This is intended to be used with buffer_handle_t's that have been
99     * received in this process through IPC.
100     *
101     * This function checks that the handle is indeed a valid one and prepares
102     * it for use with (*lock)() and (*unlock)().
103     *
104     * It is not necessary to call (*registerBuffer)() on a handle created
105     * with (*alloc_device_t::alloc)().
106     *
107     * returns an error if this buffer_handle_t is not valid.
108     */
109    int (*registerBuffer)(struct gralloc_module_t const* module,
110            buffer_handle_t handle);
111
112    /*
113     * (*unregisterBuffer)() is called once this handle is no longer needed in
114     * this process. After this call, it is an error to call (*lock)(),
115     * (*unlock)(), or (*registerBuffer)().
116     *
117     * This function doesn't close or free the handle itself; this is done
118     * by other means, usually through libcutils's native_handle_close() and
119     * native_handle_free().
120     *
121     * It is an error to call (*unregisterBuffer)() on a buffer that wasn't
122     * explicitly registered first.
123     */
124    int (*unregisterBuffer)(struct gralloc_module_t const* module,
125            buffer_handle_t handle);
126
127    /*
128     * The (*lock)() method is called before a buffer is accessed for the
129     * specified usage. This call may block, for instance if the h/w needs
130     * to finish rendering or if CPU caches need to be synchronized.
131     *
132     * The caller promises to modify only pixels in the area specified
133     * by (l,t,w,h).
134     *
135     * The content of the buffer outside of the specified area is NOT modified
136     * by this call.
137     *
138     * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address
139     * of the buffer in virtual memory.
140     *
141     * THREADING CONSIDERATIONS:
142     *
143     * It is legal for several different threads to lock a buffer from
144     * read access, none of the threads are blocked.
145     *
146     * However, locking a buffer simultaneously for write or read/write is
147     * undefined, but:
148     * - shall not result in termination of the process
149     * - shall not block the caller
150     * It is acceptable to return an error or to leave the buffer's content
151     * into an indeterminate state.
152     *
153     * If the buffer was created with a usage mask incompatible with the
154     * requested usage flags here, -EINVAL is returned.
155     *
156     */
157
158    int (*lock)(struct gralloc_module_t const* module,
159            buffer_handle_t handle, int usage,
160            int l, int t, int w, int h,
161            void** vaddr);
162
163
164    /*
165     * The (*unlock)() method must be called after all changes to the buffer
166     * are completed.
167     */
168
169    int (*unlock)(struct gralloc_module_t const* module,
170            buffer_handle_t handle);
171
172
173    /* reserved for future use */
174    int (*perform)(struct gralloc_module_t const* module,
175            int operation, ... );
176
177    /* reserved for future use */
178    void* reserved_proc[7];
179} gralloc_module_t;
180
181/*****************************************************************************/
182
183/**
184 * Every device data structure must begin with hw_device_t
185 * followed by module specific public methods and attributes.
186 */
187
188typedef struct alloc_device_t {
189    struct hw_device_t common;
190
191    /*
192     * (*alloc)() Allocates a buffer in graphic memory with the requested
193     * parameters and returns a buffer_handle_t and the stride in pixels to
194     * allow the implementation to satisfy hardware constraints on the width
195     * of a pixmap (eg: it may have to be multiple of 8 pixels).
196     * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
197     *
198     * Returns 0 on success or -errno on error.
199     */
200
201    int (*alloc)(struct alloc_device_t* dev,
202            int w, int h, int format, int usage,
203            buffer_handle_t* handle, int* stride);
204
205    /*
206     * (*free)() Frees a previously allocated buffer.
207     * Behavior is undefined if the buffer is still mapped in any process,
208     * but shall not result in termination of the program or security breaches
209     * (allowing a process to get access to another process' buffers).
210     * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
211     * invalid after the call.
212     *
213     * Returns 0 on success or -errno on error.
214     */
215    int (*free)(struct alloc_device_t* dev,
216            buffer_handle_t handle);
217
218} alloc_device_t;
219
220
221typedef struct framebuffer_device_t {
222    struct hw_device_t common;
223
224    /* flags describing some attributes of the framebuffer */
225    const uint32_t  flags;
226
227    /* dimensions of the framebuffer in pixels */
228    const uint32_t  width;
229    const uint32_t  height;
230
231    /* frambuffer stride in pixels */
232    const int       stride;
233
234    /* framebuffer pixel format */
235    const int       format;
236
237    /* resolution of the framebuffer's display panel in pixel per inch*/
238    const float     xdpi;
239    const float     ydpi;
240
241    /* framebuffer's display panel refresh rate in frames per second */
242    const float     fps;
243
244    /* min swap interval supported by this framebuffer */
245    const int       minSwapInterval;
246
247    /* max swap interval supported by this framebuffer */
248    const int       maxSwapInterval;
249
250    int reserved[8];
251
252    /*
253     * requests a specific swap-interval (same definition than EGL)
254     *
255     * Returns 0 on success or -errno on error.
256     */
257    int (*setSwapInterval)(struct framebuffer_device_t* window,
258            int interval);
259
260    /*
261     * This hook is OPTIONAL.
262     *
263     * It is non NULL If the framebuffer driver supports "update-on-demand"
264     * and the given rectangle is the area of the screen that gets
265     * updated during (*post)().
266     *
267     * This is useful on devices that are able to DMA only a portion of
268     * the screen to the display panel, upon demand -- as opposed to
269     * constantly refreshing the panel 60 times per second, for instance.
270     *
271     * Only the area defined by this rectangle is guaranteed to be valid, that
272     * is, the driver is not allowed to post anything outside of this
273     * rectangle.
274     *
275     * The rectangle evaluated during (*post)() and specifies which area
276     * of the buffer passed in (*post)() shall to be posted.
277     *
278     * return -EINVAL if width or height <=0, or if left or top < 0
279     */
280    int (*setUpdateRect)(struct framebuffer_device_t* window,
281            int left, int top, int width, int height);
282
283    /*
284     * Post <buffer> to the display (display it on the screen)
285     * The buffer must have been allocated with the
286     *   GRALLOC_USAGE_HW_FB usage flag.
287     * buffer must be the same width and height as the display and must NOT
288     * be locked.
289     *
290     * The buffer is shown during the next VSYNC.
291     *
292     * If the same buffer is posted again (possibly after some other buffer),
293     * post() will block until the the first post is completed.
294     *
295     * Internally, post() is expected to lock the buffer so that a
296     * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
297     * USAGE_*_WRITE will block until it is safe; that is typically once this
298     * buffer is shown and another buffer has been posted.
299     *
300     * Returns 0 on success or -errno on error.
301     */
302    int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
303
304
305    /*
306     * The (*compositionComplete)() method must be called after the
307     * compositor has finished issuing GL commands for client buffers.
308     */
309
310    int (*compositionComplete)(struct framebuffer_device_t* dev);
311
312
313    void* reserved_proc[8];
314
315} framebuffer_device_t;
316
317
318/** convenience API for opening and closing a supported device */
319
320static inline int gralloc_open(const struct hw_module_t* module,
321        struct alloc_device_t** device) {
322    return module->methods->open(module,
323            GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
324}
325
326static inline int gralloc_close(struct alloc_device_t* device) {
327    return device->common.close(&device->common);
328}
329
330
331static inline int framebuffer_open(const struct hw_module_t* module,
332        struct framebuffer_device_t** device) {
333    return module->methods->open(module,
334            GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
335}
336
337static inline int framebuffer_close(struct framebuffer_device_t* device) {
338    return device->common.close(&device->common);
339}
340
341
342__END_DECLS
343
344#endif  // ANDROID_ALLOC_INTERFACE_H
345