gralloc.h revision 295190f426a209cf08a21476f15e0e281db6fcb5 
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 */
83struct 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     * If the buffer was created with a usage mask incompatible with the
135     * requested usage flags here, -EINVAL is returned.
136     *
137     */
138
139    int (*lock)(struct gralloc_module_t const* module,
140            buffer_handle_t handle, int usage,
141            int l, int t, int w, int h,
142            void** vaddr);
143
144
145    /*
146     * The (*unlock)() method must be called after all changes to the buffer
147     * are completed.
148     */
149
150    int (*unlock)(struct gralloc_module_t const* module,
151            buffer_handle_t handle);
152
153};
154
155/*****************************************************************************/
156
157/**
158 * Every device data structure must begin with hw_device_t
159 * followed by module specific public methods and attributes.
160 */
161
162struct alloc_device_t {
163    struct hw_device_t common;
164
165    /*
166     * (*alloc)() Allocates a buffer in graphic memory with the requested
167     * parameters and returns a buffer_handle_t and the stride in pixels to
168     * allow the implementation to satisfy hardware constraints on the width
169     * of a pixmap (eg: it may have to be multiple of 8 pixels).
170     * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
171     *
172     * Returns 0 on success or -errno on error.
173     */
174
175    int (*alloc)(struct alloc_device_t* dev,
176            int w, int h, int format, int usage,
177            buffer_handle_t* handle, int* stride);
178
179    /*
180     * (*free)() Frees a previously allocated buffer.
181     * Behavior is undefined if the buffer is still mapped in any process,
182     * but shall not result in termination of the program or security breaches
183     * (allowing a process to get access to another process' buffers).
184     * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
185     * invalid after the call.
186     *
187     * Returns 0 on success or -errno on error.
188     */
189    int (*free)(struct alloc_device_t* dev,
190            buffer_handle_t handle);
191
192};
193
194
195struct framebuffer_device_t {
196    struct hw_device_t common;
197
198    /* flags describing some attributes of the framebuffer */
199    const uint32_t  flags;
200
201    /* dimensions of the framebuffer in pixels */
202    const uint32_t  width;
203    const uint32_t  height;
204
205    /* frambuffer stride in pixels */
206    const int       stride;
207
208    /* framebuffer pixel format */
209    const int       format;
210
211    /* resolution of the framebuffer's display panel in pixel per inch*/
212    const float     xdpi;
213    const float     ydpi;
214
215    /* framebuffer's display panel refresh rate in frames per second */
216    const float     fps;
217
218    /* min swap interval supported by this framebuffer */
219    const int       minSwapInterval;
220
221    /* max swap interval supported by this framebuffer */
222    const int       maxSwapInterval;
223
224    int reserved[8];
225
226    /*
227     * requests a specific swap-interval (same definition than EGL)
228     *
229     * Returns 0 on success or -errno on error.
230     */
231    int (*setSwapInterval)(struct framebuffer_device_t* window,
232            int interval);
233
234    /*
235     * sets a rectangle evaluated during (*post)() specifying which area
236     * of the buffer passed in (*post)() needs to be posted.
237     *
238     * return -EINVAL if width or height <=0, or if left or top < 0
239     */
240    int (*setUpdateRect)(struct framebuffer_device_t* window,
241            int left, int top, int width, int height);
242
243    /*
244     * Post <buffer> to the display (display it on the screen)
245     * The buffer must have been allocated with the
246     *   GRALLOC_USAGE_HW_FB usage flag.
247     * buffer must be the same width and height as the display and must NOT
248     * be locked.
249     *
250     * The buffer is shown during the next VSYNC.
251     *
252     * If the same buffer is posted again (possibly after some other buffer),
253     * post() will block until the the first post is completed.
254     *
255     * Internally, post() is expected to lock the buffer so that a
256     * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
257     * USAGE_*_WRITE will block until it is safe; that is typically once this
258     * buffer is shown and another buffer has been posted.
259     *
260     * Returns 0 on success or -errno on error.
261     */
262    int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
263
264    void* reserved_proc[8];
265};
266
267
268/** convenience API for opening and closing a supported device */
269
270static inline int gralloc_open(const struct hw_module_t* module,
271        struct alloc_device_t** device) {
272    return module->methods->open(module,
273            GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
274}
275
276static inline int gralloc_close(struct alloc_device_t* device) {
277    return device->common.close(&device->common);
278}
279
280
281static inline int framebuffer_open(const struct hw_module_t* module,
282        struct framebuffer_device_t** device) {
283    return module->methods->open(module,
284            GRALLOC_HARDWARE_FB0, (struct hw_device_t**)device);
285}
286
287static inline int framebuffer_close(struct framebuffer_device_t* device) {
288    return device->common.close(&device->common);
289}
290
291
292__END_DECLS
293
294#endif  // ANDROID_ALLOC_INTERFACE_H
295