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_FB_INTERFACE_H
19 #define ANDROID_FB_INTERFACE_H
20 
21 #include <stdint.h>
22 #include <sys/cdefs.h>
23 #include <sys/types.h>
24 
25 #include <cutils/native_handle.h>
26 
27 #include <hardware/hardware.h>
28 
29 __BEGIN_DECLS
30 
31 #define GRALLOC_HARDWARE_FB0 "fb0"
32 
33 /*****************************************************************************/
34 
35 
36 /*****************************************************************************/
37 
38 typedef struct framebuffer_device_t {
39     /**
40      * Common methods of the framebuffer device.  This *must* be the first member of
41      * framebuffer_device_t as users of this structure will cast a hw_device_t to
42      * framebuffer_device_t pointer in contexts where it's known the hw_device_t references a
43      * framebuffer_device_t.
44      */
45     struct hw_device_t common;
46 
47     /* flags describing some attributes of the framebuffer */
48     const uint32_t  flags;
49 
50     /* dimensions of the framebuffer in pixels */
51     const uint32_t  width;
52     const uint32_t  height;
53 
54     /* frambuffer stride in pixels */
55     const int       stride;
56 
57     /* framebuffer pixel format */
58     const int       format;
59 
60     /* resolution of the framebuffer's display panel in pixel per inch*/
61     const float     xdpi;
62     const float     ydpi;
63 
64     /* framebuffer's display panel refresh rate in frames per second */
65     const float     fps;
66 
67     /* min swap interval supported by this framebuffer */
68     const int       minSwapInterval;
69 
70     /* max swap interval supported by this framebuffer */
71     const int       maxSwapInterval;
72 
73     /* Number of framebuffers supported*/
74     const int       numFramebuffers;
75 
76     int reserved[7];
77 
78     /*
79      * requests a specific swap-interval (same definition than EGL)
80      *
81      * Returns 0 on success or -errno on error.
82      */
83     int (*setSwapInterval)(struct framebuffer_device_t* window,
84             int interval);
85 
86     /*
87      * This hook is OPTIONAL.
88      *
89      * It is non NULL If the framebuffer driver supports "update-on-demand"
90      * and the given rectangle is the area of the screen that gets
91      * updated during (*post)().
92      *
93      * This is useful on devices that are able to DMA only a portion of
94      * the screen to the display panel, upon demand -- as opposed to
95      * constantly refreshing the panel 60 times per second, for instance.
96      *
97      * Only the area defined by this rectangle is guaranteed to be valid, that
98      * is, the driver is not allowed to post anything outside of this
99      * rectangle.
100      *
101      * The rectangle evaluated during (*post)() and specifies which area
102      * of the buffer passed in (*post)() shall to be posted.
103      *
104      * return -EINVAL if width or height <=0, or if left or top < 0
105      */
106     int (*setUpdateRect)(struct framebuffer_device_t* window,
107             int left, int top, int width, int height);
108 
109     /*
110      * Post <buffer> to the display (display it on the screen)
111      * The buffer must have been allocated with the
112      *   GRALLOC_USAGE_HW_FB usage flag.
113      * buffer must be the same width and height as the display and must NOT
114      * be locked.
115      *
116      * The buffer is shown during the next VSYNC.
117      *
118      * If the same buffer is posted again (possibly after some other buffer),
119      * post() will block until the the first post is completed.
120      *
121      * Internally, post() is expected to lock the buffer so that a
122      * subsequent call to gralloc_module_t::(*lock)() with USAGE_RENDER or
123      * USAGE_*_WRITE will block until it is safe; that is typically once this
124      * buffer is shown and another buffer has been posted.
125      *
126      * Returns 0 on success or -errno on error.
127      */
128     int (*post)(struct framebuffer_device_t* dev, buffer_handle_t buffer);
129 
130 
131     /*
132      * The (*compositionComplete)() method must be called after the
133      * compositor has finished issuing GL commands for client buffers.
134      */
135 
136     int (*compositionComplete)(struct framebuffer_device_t* dev);
137 
138     /*
139      * This hook is OPTIONAL.
140      *
141      * If non NULL it will be caused by SurfaceFlinger on dumpsys
142      */
143     void (*dump)(struct framebuffer_device_t* dev, char *buff, int buff_len);
144 
145     /*
146      * (*enableScreen)() is used to either blank (enable=0) or
147      * unblank (enable=1) the screen this framebuffer is attached to.
148      *
149      * Returns 0 on success or -errno on error.
150      */
151     int (*enableScreen)(struct framebuffer_device_t* dev, int enable);
152 
153     void* reserved_proc[6];
154 
155 } framebuffer_device_t;
156 
157 
158 /** convenience API for opening and closing a supported device */
159 
framebuffer_open(const struct hw_module_t * module,struct framebuffer_device_t ** device)160 static inline int framebuffer_open(const struct hw_module_t* module,
161         struct framebuffer_device_t** device) {
162     return module->methods->open(module,
163             GRALLOC_HARDWARE_FB0, TO_HW_DEVICE_T_OPEN(device));
164 }
165 
framebuffer_close(struct framebuffer_device_t * device)166 static inline int framebuffer_close(struct framebuffer_device_t* device) {
167     return device->common.close(&device->common);
168 }
169 
170 
171 __END_DECLS
172 
173 #endif  // ANDROID_FB_INTERFACE_H
174