| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdint.h> |
| #include <sys/types.h> |
| |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <math.h> |
| #include <time.h> |
| #include <errno.h> |
| |
| #include <sys/resource.h> |
| #include <sys/syscall.h> |
| #include <sys/mman.h> |
| |
| #include <linux/fb.h> |
| |
| int64_t systemTime() |
| { |
| struct timespec t; |
| t.tv_sec = t.tv_nsec = 0; |
| clock_gettime(CLOCK_MONOTONIC, &t); |
| return (int64_t)(t.tv_sec)*1000000000LL + t.tv_nsec; |
| } |
| |
| int main(int argc, char** argv) |
| { |
| char const * const device_template[] = { |
| "/dev/graphics/fb%u", |
| "/dev/fb%u", |
| 0 }; |
| int fd = -1; |
| int i=0; |
| int j=0; |
| char name[64]; |
| while ((fd==-1) && device_template[i]) { |
| snprintf(name, 64, device_template[i], 0); |
| fd = open(name, O_RDWR, 0); |
| i++; |
| } |
| if (fd < 0) |
| return -errno; |
| |
| struct fb_fix_screeninfo finfo; |
| if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1) |
| return -errno; |
| |
| struct fb_var_screeninfo info; |
| if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1) |
| return -errno; |
| |
| info.reserved[0] = 0; |
| info.reserved[1] = 0; |
| info.reserved[2] = 0; |
| info.xoffset = 0; |
| info.yoffset = 0; |
| info.bits_per_pixel = 16; |
| info.activate = FB_ACTIVATE_NOW; |
| |
| if (ioctl(fd, FBIOPUT_VSCREENINFO, &info) == -1) { |
| printf("FBIOPUT_VSCREENINFO failed (%d x %d)\n", |
| info.xres_virtual, info.yres_virtual); |
| return 0; |
| } |
| |
| if (ioctl(fd, FBIOGET_VSCREENINFO, &info) == -1) |
| return -errno; |
| |
| int refreshRate = 1000000000000000LLU / |
| ( |
| (uint64_t)( info.upper_margin + info.lower_margin + info.yres ) |
| * ( info.left_margin + info.right_margin + info.xres ) |
| * info.pixclock |
| ); |
| |
| float xdpi = (info.xres * 25.4f) / info.width; |
| float ydpi = (info.yres * 25.4f) / info.height; |
| float fps = refreshRate / 1000.0f; |
| |
| printf( "using (fd=%d)\n" |
| "id = %s\n" |
| "xres = %d px\n" |
| "yres = %d px\n" |
| "xres_virtual = %d px\n" |
| "yres_virtual = %d px\n" |
| "bpp = %d\n" |
| "r = %2u:%u\n" |
| "g = %2u:%u\n" |
| "b = %2u:%u\n", |
| fd, |
| finfo.id, |
| info.xres, |
| info.yres, |
| info.xres_virtual, |
| info.yres_virtual, |
| info.bits_per_pixel, |
| info.red.offset, info.red.length, |
| info.green.offset, info.green.length, |
| info.blue.offset, info.blue.length |
| ); |
| |
| printf( "width = %d mm (%f dpi)\n" |
| "height = %d mm (%f dpi)\n" |
| "refresh rate = %.2f Hz\n", |
| info.width, xdpi, |
| info.height, ydpi, |
| fps |
| ); |
| |
| printf("upper_margin=%d, lower_margin=%d, left_margin=%d, right_margin=%d, pixclock=%d, finfo.smem_len=%d\n", |
| info.upper_margin, info.lower_margin, info.left_margin, info.right_margin, info.pixclock, finfo.smem_len); |
| |
| if (ioctl(fd, FBIOGET_FSCREENINFO, &finfo) == -1) |
| return -errno; |
| |
| if (finfo.smem_len <= 0) |
| return -errno; |
| |
| /* |
| * Open and map the display. |
| */ |
| |
| uint16_t* buffer = (uint16_t*) mmap( |
| 0, finfo.smem_len, |
| PROT_READ | PROT_WRITE, |
| MAP_SHARED, |
| fd, 0); |
| |
| if (buffer == MAP_FAILED) |
| return -errno; |
| |
| // at least for now, always clear the fb |
| memset(buffer, 0, finfo.smem_len); |
| memset(buffer, 0xff, 320*(info.yres_virtual/2)*2); |
| |
| int l,t,w,h; |
| l=0; |
| t=0; |
| w=320; |
| h=480; |
| info.reserved[0] = 0x54445055; // "UPDT"; |
| info.reserved[1] = (uint16_t)l | ((uint32_t)t << 16); |
| info.reserved[2] = (uint16_t)(l+w) | ((uint32_t)(t+h) << 16); |
| |
| int err; |
| int c = 0; |
| int64_t time = systemTime(); |
| while (1) { |
| |
| info.activate = FB_ACTIVATE_VBL; |
| info.yoffset = 0; |
| ioctl(fd, FBIOPUT_VSCREENINFO, &info); |
| |
| info.activate = FB_ACTIVATE_VBL; |
| info.yoffset = info.yres_virtual/2; |
| err = ioctl(fd, FBIOPUT_VSCREENINFO, &info); |
| |
| c+=2; |
| if (c==60*2) { |
| int64_t now = systemTime(); |
| time = now - time; |
| printf("refresh rate = %f Hz\n", (c*1000000000.0 / (double)time)); |
| c = 0; |
| time = now; |
| } |
| } |
| return 0; |
| } |