gralloc.h revision 95d78bef32edd183fb8c16b7775bf0a069948420 
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    /* implementation-specific private usage flags */
74    GRALLOC_USAGE_PRIVATE_0       = 0x10000000,
75    GRALLOC_USAGE_PRIVATE_1       = 0x20000000,
76    GRALLOC_USAGE_PRIVATE_2       = 0x40000000,
77    GRALLOC_USAGE_PRIVATE_3       = 0x80000000,
78    GRALLOC_USAGE_PRIVATE_MASK    = 0xF0000000,
79};
80
81/*****************************************************************************/
82
83typedef const native_handle* buffer_handle_t;
84
85enum {
86    /* FIXME: this only exists to work-around some issues with
87     * the video and camera frameworks. don't implement unless
88     * you know what you're doing.
89     */
90    GRALLOC_MODULE_PERFORM_CREATE_HANDLE_FROM_BUFFER = 0x080000001,
91};
92
93/**
94 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
95 * and the fields of this data structure must begin with hw_module_t
96 * followed by module specific information.
97 */
98typedef struct gralloc_module_t {
99    struct hw_module_t common;
100
101    /*
102     * (*registerBuffer)() must be called before a buffer_handle_t that has not
103     * been created with (*alloc_device_t::alloc)() can be used.
104     *
105     * This is intended to be used with buffer_handle_t's that have been
106     * received in this process through IPC.
107     *
108     * This function checks that the handle is indeed a valid one and prepares
109     * it for use with (*lock)() and (*unlock)().
110     *
111     * It is not necessary to call (*registerBuffer)() on a handle created
112     * with (*alloc_device_t::alloc)().
113     *
114     * returns an error if this buffer_handle_t is not valid.
115     */
116    int (*registerBuffer)(struct gralloc_module_t const* module,
117            buffer_handle_t handle);
118
119    /*
120     * (*unregisterBuffer)() is called once this handle is no longer needed in
121     * this process. After this call, it is an error to call (*lock)(),
122     * (*unlock)(), or (*registerBuffer)().
123     *
124     * This function doesn't close or free the handle itself; this is done
125     * by other means, usually through libcutils's native_handle_close() and
126     * native_handle_free().
127     *
128     * It is an error to call (*unregisterBuffer)() on a buffer that wasn't
129     * explicitly registered first.
130     */
131    int (*unregisterBuffer)(struct gralloc_module_t const* module,
132            buffer_handle_t handle);
133
134    /*
135     * The (*lock)() method is called before a buffer is accessed for the
136     * specified usage. This call may block, for instance if the h/w needs
137     * to finish rendering or if CPU caches need to be synchronized.
138     *
139     * The caller promises to modify only pixels in the area specified
140     * by (l,t,w,h).
141     *
142     * The content of the buffer outside of the specified area is NOT modified
143     * by this call.
144     *
145     * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address
146     * of the buffer in virtual memory.
147     *
148     * THREADING CONSIDERATIONS:
149     *
150     * It is legal for several different threads to lock a buffer from
151     * read access, none of the threads are blocked.
152     *
153     * However, locking a buffer simultaneously for write or read/write is
154     * undefined, but:
155     * - shall not result in termination of the process
156     * - shall not block the caller
157     * It is acceptable to return an error or to leave the buffer's content
158     * into an indeterminate state.
159     *
160     * If the buffer was created with a usage mask incompatible with the
161     * requested usage flags here, -EINVAL is returned.
162     *
163     */
164
165    int (*lock)(struct gralloc_module_t const* module,
166            buffer_handle_t handle, int usage,
167            int l, int t, int w, int h,
168            void** vaddr);
169
170
171    /*
172     * The (*unlock)() method must be called after all changes to the buffer
173     * are completed.
174     */
175
176    int (*unlock)(struct gralloc_module_t const* module,
177            buffer_handle_t handle);
178
179
180    /* reserved for future use */
181    int (*perform)(struct gralloc_module_t const* module,
182            int operation, ... );
183
184    /* reserved for future use */
185    void* reserved_proc[7];
186} gralloc_module_t;
187
188/*****************************************************************************/
189
190/**
191 * Every device data structure must begin with hw_device_t
192 * followed by module specific public methods and attributes.
193 */
194
195typedef struct alloc_device_t {
196    struct hw_device_t common;
197
198    /*
199     * (*alloc)() Allocates a buffer in graphic memory with the requested
200     * parameters and returns a buffer_handle_t and the stride in pixels to
201     * allow the implementation to satisfy hardware constraints on the width
202     * of a pixmap (eg: it may have to be multiple of 8 pixels).
203     * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
204     *
205     * Returns 0 on success or -errno on error.
206     */
207
208    int (*alloc)(struct alloc_device_t* dev,
209            int w, int h, int format, int usage,
210            buffer_handle_t* handle, int* stride);
211
212    /*
213     * (*free)() Frees a previously allocated buffer.
214     * Behavior is undefined if the buffer is still mapped in any process,
215     * but shall not result in termination of the program or security breaches
216     * (allowing a process to get access to another process' buffers).
217     * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
218     * invalid after the call.
219     *
220     * Returns 0 on success or -errno on error.
221     */
222    int (*free)(struct alloc_device_t* dev,
223            buffer_handle_t handle);
224
225} alloc_device_t;
226
227
228typedef struct framebuffer_device_t {
229    struct hw_device_t common;
230
231    /* flags describing some attributes of the framebuffer */
232    const uint32_t  flags;
233
234    /* dimensions of the framebuffer in pixels */
235    const uint32_t  width;
236    const uint32_t  height;
237
238    /* frambuffer stride in pixels */
239    const int       stride;
240
241    /* framebuffer pixel format */
242    const int       format;
243
244    /* resolution of the framebuffer's display panel in pixel per inch*/
245    const float     xdpi;
246    const float     ydpi;
247
248    /* framebuffer's display panel refresh rate in frames per second */
249    const float     fps;
250
251    /* min swap interval supported by this framebuffer */
252    const int       minSwapInterval;
253
254    /* max swap interval supported by this framebuffer */
255    const int       maxSwapInterval;
256
257    int reserved[8];
258
259    /*
260     * requests a specific swap-interval (same definition than EGL)
261     *
262     * Returns 0 on success or -errno on error.
263     */
264    int (*setSwapInterval)(struct framebuffer_device_t* window,
265            int interval);
266
267    /*
268     * This hook is OPTIONAL.
269     *
270     * It is non NULL If the framebuffer driver supports "update-on-demand"
271     * and the given rectangle is the area of the screen that gets
272     * updated during (*post)().
273     *
274     * This is useful on devices that are able to DMA only a portion of
275     * the screen to the display panel, upon demand -- as opposed to
276     * constantly refreshing the panel 60 times per second, for instance.
277     *
278     * Only the area defined by this rectangle is guaranteed to be valid, that
279     * is, the driver is not allowed to post anything outside of this
280     * rectangle.
281     *
282     * The rectangle evaluated during (*post)() and specifies which area
283     * of the buffer passed in (*post)() shall to be posted.
284     *
285     * return -EINVAL if width or height <=0, or if left or top < 0
286     */
287    int (*setUpdateRect)(struct framebuffer_device_t* window,
288            int left, int top, int width, int height);
289
290    /*
291     * Post <buffer> to the display (display it on the screen)
292     * The buffer must have been allocated with the
293     *   GRALLOC_USAGE_HW_FB usage flag.
294     * buffer must be the same width and height as the display and must NOT
295     * be locked.
296     *
297     * The buffer is shown during the next VSYNC.
298     *
299     * If the same buffer is posted again (possibly after some other buffer),
300     * post() will block until the the first post is completed.
301     *
302     * Internally, post() is expected to lock the buffer so that a
303     * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
304     * USAGE_*_WRITE will block until it is safe; that is typically once this
305     * buffer is shown and another buffer has been posted.
306     *
307     * Returns 0 on success or -errno on error.
308     */
309    int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
310
311
312    /*
313     * The (*compositionComplete)() method must be called after the
314     * compositor has finished issuing GL commands for client buffers.
315     */
316
317    int (*compositionComplete)(struct framebuffer_device_t* dev);
318
319
320    void* reserved_proc[8];
321
322} framebuffer_device_t;
323
324
325/** convenience API for opening and closing a supported device */
326
327static inline int gralloc_open(const struct hw_module_t* module,
328        struct alloc_device_t** device) {
329    return module->methods->open(module,
330            GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
331}
332
333static inline int gralloc_close(struct alloc_device_t* device) {
334    return device->common.close(&device->common);
335}
336
337
338static inline int framebuffer_open(const struct hw_module_t* module,
339        struct framebuffer_device_t** device) {
340    return module->methods->open(module,
341            GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
342}
343
344static inline int framebuffer_close(struct framebuffer_device_t* device) {
345    return device->common.close(&device->common);
346}
347
348
349__END_DECLS
350
351#endif  // ANDROID_ALLOC_INTERFACE_H
352