gralloc.h revision 7edeaf91a8d066e6797f875451f8aa9e9a4682f6 
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           = 0x00000400,
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    /* buffer should be displayed full-screen on an external display when
74     * possible
75     */
76    GRALLOC_USAGE_EXTERNAL_DISP   = 0x00002000,
77
78    /* implementation-specific private usage flags */
79    GRALLOC_USAGE_PRIVATE_0       = 0x10000000,
80    GRALLOC_USAGE_PRIVATE_1       = 0x20000000,
81    GRALLOC_USAGE_PRIVATE_2       = 0x40000000,
82    GRALLOC_USAGE_PRIVATE_3       = 0x80000000,
83    GRALLOC_USAGE_PRIVATE_MASK    = 0xF0000000,
84};
85
86/*****************************************************************************/
87
88typedef const native_handle* buffer_handle_t;
89
90enum {
91    /* FIXME: this only exists to work-around some issues with
92     * the video and camera frameworks. don't implement unless
93     * you know what you're doing.
94     */
95    GRALLOC_MODULE_PERFORM_CREATE_HANDLE_FROM_BUFFER = 0x080000001,
96};
97
98/**
99 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
100 * and the fields of this data structure must begin with hw_module_t
101 * followed by module specific information.
102 */
103typedef struct gralloc_module_t {
104    struct hw_module_t common;
105
106    /*
107     * (*registerBuffer)() must be called before a buffer_handle_t that has not
108     * been created with (*alloc_device_t::alloc)() can be used.
109     *
110     * This is intended to be used with buffer_handle_t's that have been
111     * received in this process through IPC.
112     *
113     * This function checks that the handle is indeed a valid one and prepares
114     * it for use with (*lock)() and (*unlock)().
115     *
116     * It is not necessary to call (*registerBuffer)() on a handle created
117     * with (*alloc_device_t::alloc)().
118     *
119     * returns an error if this buffer_handle_t is not valid.
120     */
121    int (*registerBuffer)(struct gralloc_module_t const* module,
122            buffer_handle_t handle);
123
124    /*
125     * (*unregisterBuffer)() is called once this handle is no longer needed in
126     * this process. After this call, it is an error to call (*lock)(),
127     * (*unlock)(), or (*registerBuffer)().
128     *
129     * This function doesn't close or free the handle itself; this is done
130     * by other means, usually through libcutils's native_handle_close() and
131     * native_handle_free().
132     *
133     * It is an error to call (*unregisterBuffer)() on a buffer that wasn't
134     * explicitly registered first.
135     */
136    int (*unregisterBuffer)(struct gralloc_module_t const* module,
137            buffer_handle_t handle);
138
139    /*
140     * The (*lock)() method is called before a buffer is accessed for the
141     * specified usage. This call may block, for instance if the h/w needs
142     * to finish rendering or if CPU caches need to be synchronized.
143     *
144     * The caller promises to modify only pixels in the area specified
145     * by (l,t,w,h).
146     *
147     * The content of the buffer outside of the specified area is NOT modified
148     * by this call.
149     *
150     * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address
151     * of the buffer in virtual memory.
152     *
153     * THREADING CONSIDERATIONS:
154     *
155     * It is legal for several different threads to lock a buffer from
156     * read access, none of the threads are blocked.
157     *
158     * However, locking a buffer simultaneously for write or read/write is
159     * undefined, but:
160     * - shall not result in termination of the process
161     * - shall not block the caller
162     * It is acceptable to return an error or to leave the buffer's content
163     * into an indeterminate state.
164     *
165     * If the buffer was created with a usage mask incompatible with the
166     * requested usage flags here, -EINVAL is returned.
167     *
168     */
169
170    int (*lock)(struct gralloc_module_t const* module,
171            buffer_handle_t handle, int usage,
172            int l, int t, int w, int h,
173            void** vaddr);
174
175
176    /*
177     * The (*unlock)() method must be called after all changes to the buffer
178     * are completed.
179     */
180
181    int (*unlock)(struct gralloc_module_t const* module,
182            buffer_handle_t handle);
183
184
185    /* reserved for future use */
186    int (*perform)(struct gralloc_module_t const* module,
187            int operation, ... );
188
189    /* reserved for future use */
190    void* reserved_proc[7];
191} gralloc_module_t;
192
193/*****************************************************************************/
194
195/**
196 * Every device data structure must begin with hw_device_t
197 * followed by module specific public methods and attributes.
198 */
199
200typedef struct alloc_device_t {
201    struct hw_device_t common;
202
203    /*
204     * (*alloc)() Allocates a buffer in graphic memory with the requested
205     * parameters and returns a buffer_handle_t and the stride in pixels to
206     * allow the implementation to satisfy hardware constraints on the width
207     * of a pixmap (eg: it may have to be multiple of 8 pixels).
208     * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
209     *
210     * Returns 0 on success or -errno on error.
211     */
212
213    int (*alloc)(struct alloc_device_t* dev,
214            int w, int h, int format, int usage,
215            buffer_handle_t* handle, int* stride);
216
217    /*
218     * (*free)() Frees a previously allocated buffer.
219     * Behavior is undefined if the buffer is still mapped in any process,
220     * but shall not result in termination of the program or security breaches
221     * (allowing a process to get access to another process' buffers).
222     * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
223     * invalid after the call.
224     *
225     * Returns 0 on success or -errno on error.
226     */
227    int (*free)(struct alloc_device_t* dev,
228            buffer_handle_t handle);
229
230} alloc_device_t;
231
232
233typedef struct framebuffer_device_t {
234    struct hw_device_t common;
235
236    /* flags describing some attributes of the framebuffer */
237    const uint32_t  flags;
238
239    /* dimensions of the framebuffer in pixels */
240    const uint32_t  width;
241    const uint32_t  height;
242
243    /* frambuffer stride in pixels */
244    const int       stride;
245
246    /* framebuffer pixel format */
247    const int       format;
248
249    /* resolution of the framebuffer's display panel in pixel per inch*/
250    const float     xdpi;
251    const float     ydpi;
252
253    /* framebuffer's display panel refresh rate in frames per second */
254    const float     fps;
255
256    /* min swap interval supported by this framebuffer */
257    const int       minSwapInterval;
258
259    /* max swap interval supported by this framebuffer */
260    const int       maxSwapInterval;
261
262    int reserved[8];
263
264    /*
265     * requests a specific swap-interval (same definition than EGL)
266     *
267     * Returns 0 on success or -errno on error.
268     */
269    int (*setSwapInterval)(struct framebuffer_device_t* window,
270            int interval);
271
272    /*
273     * This hook is OPTIONAL.
274     *
275     * It is non NULL If the framebuffer driver supports "update-on-demand"
276     * and the given rectangle is the area of the screen that gets
277     * updated during (*post)().
278     *
279     * This is useful on devices that are able to DMA only a portion of
280     * the screen to the display panel, upon demand -- as opposed to
281     * constantly refreshing the panel 60 times per second, for instance.
282     *
283     * Only the area defined by this rectangle is guaranteed to be valid, that
284     * is, the driver is not allowed to post anything outside of this
285     * rectangle.
286     *
287     * The rectangle evaluated during (*post)() and specifies which area
288     * of the buffer passed in (*post)() shall to be posted.
289     *
290     * return -EINVAL if width or height <=0, or if left or top < 0
291     */
292    int (*setUpdateRect)(struct framebuffer_device_t* window,
293            int left, int top, int width, int height);
294
295    /*
296     * Post <buffer> to the display (display it on the screen)
297     * The buffer must have been allocated with the
298     *   GRALLOC_USAGE_HW_FB usage flag.
299     * buffer must be the same width and height as the display and must NOT
300     * be locked.
301     *
302     * The buffer is shown during the next VSYNC.
303     *
304     * If the same buffer is posted again (possibly after some other buffer),
305     * post() will block until the the first post is completed.
306     *
307     * Internally, post() is expected to lock the buffer so that a
308     * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
309     * USAGE_*_WRITE will block until it is safe; that is typically once this
310     * buffer is shown and another buffer has been posted.
311     *
312     * Returns 0 on success or -errno on error.
313     */
314    int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
315
316
317    /*
318     * The (*compositionComplete)() method must be called after the
319     * compositor has finished issuing GL commands for client buffers.
320     */
321
322    int (*compositionComplete)(struct framebuffer_device_t* dev);
323
324
325    void* reserved_proc[8];
326
327} framebuffer_device_t;
328
329
330/** convenience API for opening and closing a supported device */
331
332static inline int gralloc_open(const struct hw_module_t* module,
333        struct alloc_device_t** device) {
334    return module->methods->open(module,
335            GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
336}
337
338static inline int gralloc_close(struct alloc_device_t* device) {
339    return device->common.close(&device->common);
340}
341
342
343static inline int framebuffer_open(const struct hw_module_t* module,
344        struct framebuffer_device_t** device) {
345    return module->methods->open(module,
346            GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
347}
348
349static inline int framebuffer_close(struct framebuffer_device_t* device) {
350    return device->common.close(&device->common);
351}
352
353
354__END_DECLS
355
356#endif  // ANDROID_ALLOC_INTERFACE_H
357