1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "graphics_fbdev.h"
#include <fcntl.h>
#include <linux/fb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include "minui/minui.h"
MinuiBackendFbdev::MinuiBackendFbdev() : gr_draw(nullptr), fb_fd(-1) {}
void MinuiBackendFbdev::Blank(bool blank) {
int ret = ioctl(fb_fd, FBIOBLANK, blank ? FB_BLANK_POWERDOWN : FB_BLANK_UNBLANK);
if (ret < 0) perror("ioctl(): blank");
}
void MinuiBackendFbdev::SetDisplayedFramebuffer(unsigned n) {
if (n > 1 || !double_buffered) return;
vi.yres_virtual = gr_framebuffer[0].height * 2;
vi.yoffset = n * gr_framebuffer[0].height;
vi.bits_per_pixel = gr_framebuffer[0].pixel_bytes * 8;
if (ioctl(fb_fd, FBIOPUT_VSCREENINFO, &vi) < 0) {
perror("active fb swap failed");
}
displayed_buffer = n;
}
GRSurface* MinuiBackendFbdev::Init() {
int fd = open("/dev/graphics/fb0", O_RDWR);
if (fd == -1) {
perror("cannot open fb0");
return nullptr;
}
fb_fix_screeninfo fi;
if (ioctl(fd, FBIOGET_FSCREENINFO, &fi) < 0) {
perror("failed to get fb0 info");
close(fd);
return nullptr;
}
if (ioctl(fd, FBIOGET_VSCREENINFO, &vi) < 0) {
perror("failed to get fb0 info");
close(fd);
return nullptr;
}
// We print this out for informational purposes only, but
// throughout we assume that the framebuffer device uses an RGBX
// pixel format. This is the case for every development device I
// have access to. For some of those devices (eg, hammerhead aka
// Nexus 5), FBIOGET_VSCREENINFO *reports* that it wants a
// different format (XBGR) but actually produces the correct
// results on the display when you write RGBX.
//
// If you have a device that actually *needs* another pixel format
// (ie, BGRX, or 565), patches welcome...
printf(
"fb0 reports (possibly inaccurate):\n"
" vi.bits_per_pixel = %d\n"
" vi.red.offset = %3d .length = %3d\n"
" vi.green.offset = %3d .length = %3d\n"
" vi.blue.offset = %3d .length = %3d\n",
vi.bits_per_pixel, vi.red.offset, vi.red.length, vi.green.offset, vi.green.length,
vi.blue.offset, vi.blue.length);
void* bits = mmap(0, fi.smem_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (bits == MAP_FAILED) {
perror("failed to mmap framebuffer");
close(fd);
return nullptr;
}
memset(bits, 0, fi.smem_len);
gr_framebuffer[0].width = vi.xres;
gr_framebuffer[0].height = vi.yres;
gr_framebuffer[0].row_bytes = fi.line_length;
gr_framebuffer[0].pixel_bytes = vi.bits_per_pixel / 8;
gr_framebuffer[0].buffer_ = static_cast<uint8_t*>(bits);
memset(gr_framebuffer[0].buffer_, 0, gr_framebuffer[0].height * gr_framebuffer[0].row_bytes);
/* check if we can use double buffering */
if (vi.yres * fi.line_length * 2 <= fi.smem_len) {
double_buffered = true;
gr_framebuffer[1] = gr_framebuffer[0];
gr_framebuffer[1].buffer_ =
gr_framebuffer[0].buffer_ + gr_framebuffer[0].height * gr_framebuffer[0].row_bytes;
gr_draw = gr_framebuffer + 1;
} else {
double_buffered = false;
// Without double-buffering, we allocate RAM for a buffer to
// draw in, and then "flipping" the buffer consists of a
// memcpy from the buffer we allocated to the framebuffer.
gr_draw = new GRSurfaceFbdev;
*gr_draw = gr_framebuffer[0];
gr_draw->buffer_ = new uint8_t[gr_draw->height * gr_draw->row_bytes];
}
memset(gr_draw->buffer_, 0, gr_draw->height * gr_draw->row_bytes);
fb_fd = fd;
SetDisplayedFramebuffer(0);
printf("framebuffer: %d (%d x %d)\n", fb_fd, gr_draw->width, gr_draw->height);
Blank(true);
Blank(false);
return gr_draw;
}
GRSurface* MinuiBackendFbdev::Flip() {
if (double_buffered) {
// Change gr_draw to point to the buffer currently displayed,
// then flip the driver so we're displaying the other buffer
// instead.
gr_draw = gr_framebuffer + displayed_buffer;
SetDisplayedFramebuffer(1 - displayed_buffer);
} else {
// Copy from the in-memory surface to the framebuffer.
memcpy(gr_framebuffer[0].buffer_, gr_draw->buffer_, gr_draw->height * gr_draw->row_bytes);
}
return gr_draw;
}
MinuiBackendFbdev::~MinuiBackendFbdev() {
close(fb_fd);
fb_fd = -1;
if (!double_buffered && gr_draw) {
delete[] gr_draw->buffer_;
delete gr_draw;
}
gr_draw = nullptr;
}
|
