gralloc.h revision 4b560d5563ee4699cd24938c2f13b4a416408273 
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 <system/window.h>
22#include <hardware/hardware.h>
23
24#include <stdint.h>
25#include <sys/cdefs.h>
26#include <sys/types.h>
27
28#include <cutils/native_handle.h>
29
30#include <hardware/hardware.h>
31#include <hardware/fb.h>
32
33__BEGIN_DECLS
34
35#define GRALLOC_API_VERSION 1
36
37/**
38 * The id of this module
39 */
40#define GRALLOC_HARDWARE_MODULE_ID "gralloc"
41
42/**
43 * Name of the graphics device to open
44 */
45
46#define GRALLOC_HARDWARE_GPU0 "gpu0"
47
48enum {
49    /* buffer is never read in software */
50    GRALLOC_USAGE_SW_READ_NEVER   = 0x00000000,
51    /* buffer is rarely read in software */
52    GRALLOC_USAGE_SW_READ_RARELY  = 0x00000002,
53    /* buffer is often read in software */
54    GRALLOC_USAGE_SW_READ_OFTEN   = 0x00000003,
55    /* mask for the software read values */
56    GRALLOC_USAGE_SW_READ_MASK    = 0x0000000F,
57
58    /* buffer is never written in software */
59    GRALLOC_USAGE_SW_WRITE_NEVER  = 0x00000000,
60    /* buffer is never written in software */
61    GRALLOC_USAGE_SW_WRITE_RARELY = 0x00000020,
62    /* buffer is never written in software */
63    GRALLOC_USAGE_SW_WRITE_OFTEN  = 0x00000030,
64    /* mask for the software write values */
65    GRALLOC_USAGE_SW_WRITE_MASK   = 0x000000F0,
66
67    /* buffer will be used as an OpenGL ES texture */
68    GRALLOC_USAGE_HW_TEXTURE      = 0x00000100,
69    /* buffer will be used as an OpenGL ES render target */
70    GRALLOC_USAGE_HW_RENDER       = 0x00000200,
71    /* buffer will be used by the 2D hardware blitter */
72    GRALLOC_USAGE_HW_2D           = 0x00000400,
73    /* buffer will be used by the HWComposer HAL module */
74    GRALLOC_USAGE_HW_COMPOSER     = 0x00000800,
75    /* buffer will be used with the framebuffer device */
76    GRALLOC_USAGE_HW_FB           = 0x00001000,
77    /* mask for the software usage bit-mask */
78    GRALLOC_USAGE_HW_MASK         = 0x00001F00,
79
80    /* buffer should be displayed full-screen on an external display when
81     * possible
82     */
83    GRALLOC_USAGE_EXTERNAL_DISP   = 0x00002000,
84
85    /* Must have a hardware-protected path to external display sink for
86     * this buffer.  If a hardware-protected path is not available, then
87     * either don't composite only this buffer (preferred) to the
88     * external sink, or (less desirable) do not route the entire
89     * composition to the external sink.
90     */
91    GRALLOC_USAGE_PROTECTED       = 0x00004000,
92
93    /* implementation-specific private usage flags */
94    GRALLOC_USAGE_PRIVATE_0       = 0x10000000,
95    GRALLOC_USAGE_PRIVATE_1       = 0x20000000,
96    GRALLOC_USAGE_PRIVATE_2       = 0x40000000,
97    GRALLOC_USAGE_PRIVATE_3       = 0x80000000,
98    GRALLOC_USAGE_PRIVATE_MASK    = 0xF0000000,
99};
100
101/*****************************************************************************/
102
103/**
104 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
105 * and the fields of this data structure must begin with hw_module_t
106 * followed by module specific information.
107 */
108typedef struct gralloc_module_t {
109    struct hw_module_t common;
110
111    /*
112     * (*registerBuffer)() must be called before a buffer_handle_t that has not
113     * been created with (*alloc_device_t::alloc)() can be used.
114     *
115     * This is intended to be used with buffer_handle_t's that have been
116     * received in this process through IPC.
117     *
118     * This function checks that the handle is indeed a valid one and prepares
119     * it for use with (*lock)() and (*unlock)().
120     *
121     * It is not necessary to call (*registerBuffer)() on a handle created
122     * with (*alloc_device_t::alloc)().
123     *
124     * returns an error if this buffer_handle_t is not valid.
125     */
126    int (*registerBuffer)(struct gralloc_module_t const* module,
127            buffer_handle_t handle);
128
129    /*
130     * (*unregisterBuffer)() is called once this handle is no longer needed in
131     * this process. After this call, it is an error to call (*lock)(),
132     * (*unlock)(), or (*registerBuffer)().
133     *
134     * This function doesn't close or free the handle itself; this is done
135     * by other means, usually through libcutils's native_handle_close() and
136     * native_handle_free().
137     *
138     * It is an error to call (*unregisterBuffer)() on a buffer that wasn't
139     * explicitly registered first.
140     */
141    int (*unregisterBuffer)(struct gralloc_module_t const* module,
142            buffer_handle_t handle);
143
144    /*
145     * The (*lock)() method is called before a buffer is accessed for the
146     * specified usage. This call may block, for instance if the h/w needs
147     * to finish rendering or if CPU caches need to be synchronized.
148     *
149     * The caller promises to modify only pixels in the area specified
150     * by (l,t,w,h).
151     *
152     * The content of the buffer outside of the specified area is NOT modified
153     * by this call.
154     *
155     * If usage specifies GRALLOC_USAGE_SW_*, vaddr is filled with the address
156     * of the buffer in virtual memory.
157     *
158     * THREADING CONSIDERATIONS:
159     *
160     * It is legal for several different threads to lock a buffer from
161     * read access, none of the threads are blocked.
162     *
163     * However, locking a buffer simultaneously for write or read/write is
164     * undefined, but:
165     * - shall not result in termination of the process
166     * - shall not block the caller
167     * It is acceptable to return an error or to leave the buffer's content
168     * into an indeterminate state.
169     *
170     * If the buffer was created with a usage mask incompatible with the
171     * requested usage flags here, -EINVAL is returned.
172     *
173     */
174
175    int (*lock)(struct gralloc_module_t const* module,
176            buffer_handle_t handle, int usage,
177            int l, int t, int w, int h,
178            void** vaddr);
179
180
181    /*
182     * The (*unlock)() method must be called after all changes to the buffer
183     * are completed.
184     */
185
186    int (*unlock)(struct gralloc_module_t const* module,
187            buffer_handle_t handle);
188
189
190    /* reserved for future use */
191    int (*perform)(struct gralloc_module_t const* module,
192            int operation, ... );
193
194    /* reserved for future use */
195    void* reserved_proc[7];
196} gralloc_module_t;
197
198/*****************************************************************************/
199
200/**
201 * Every device data structure must begin with hw_device_t
202 * followed by module specific public methods and attributes.
203 */
204
205typedef struct alloc_device_t {
206    struct hw_device_t common;
207
208    /*
209     * (*alloc)() Allocates a buffer in graphic memory with the requested
210     * parameters and returns a buffer_handle_t and the stride in pixels to
211     * allow the implementation to satisfy hardware constraints on the width
212     * of a pixmap (eg: it may have to be multiple of 8 pixels).
213     * The CALLER TAKES OWNERSHIP of the buffer_handle_t.
214     *
215     * Returns 0 on success or -errno on error.
216     */
217
218    int (*alloc)(struct alloc_device_t* dev,
219            int w, int h, int format, int usage,
220            buffer_handle_t* handle, int* stride);
221
222    /*
223     * (*free)() Frees a previously allocated buffer.
224     * Behavior is undefined if the buffer is still mapped in any process,
225     * but shall not result in termination of the program or security breaches
226     * (allowing a process to get access to another process' buffers).
227     * THIS FUNCTION TAKES OWNERSHIP of the buffer_handle_t which becomes
228     * invalid after the call.
229     *
230     * Returns 0 on success or -errno on error.
231     */
232    int (*free)(struct alloc_device_t* dev,
233            buffer_handle_t handle);
234
235    /* This hook is OPTIONAL.
236     *
237     * If non NULL it will be caused by SurfaceFlinger on dumpsys
238     */
239    void (*dump)(struct alloc_device_t *dev, char *buff, int buff_len);
240
241    void* reserved_proc[7];
242} alloc_device_t;
243
244
245/** convenience API for opening and closing a supported device */
246
247static inline int gralloc_open(const struct hw_module_t* module,
248        struct alloc_device_t** device) {
249    return module->methods->open(module,
250            GRALLOC_HARDWARE_GPU0, (struct hw_device_t**)device);
251}
252
253static inline int gralloc_close(struct alloc_device_t* device) {
254    return device->common.close(&device->common);
255}
256
257__END_DECLS
258
259#endif  // ANDROID_ALLOC_INTERFACE_H
260