common/fbdev.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <fcntl.h>
   7 #include <sys/ioctl.h>
   8 #include <sys/mman.h>
   9 #include <unistd.h>
  10 #include <linux/fb.h>
  11 #include <linux/matroxfb.h>
  12
  13 #include "fbdev.h"
  14
  15 #define FBDEV_MAX_BUFFERS 3
  16
  17 struct vout_fbdev {
  18         int     fd;
  19         void    *mem;
  20         size_t  mem_size;
  21         struct  fb_var_screeninfo fbvar_old;
  22         struct  fb_var_screeninfo fbvar_new;
  23         int     buffer_write;
  24         void    *buffers[FBDEV_MAX_BUFFERS];
  25         int     buffer_count;
  26 };
  27
  28 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  29 {
  30         int draw_buf;
  31
  32         if (fbdev->buffer_count < 2)
  33                 return fbdev->mem;
  34
  35         draw_buf = fbdev->buffer_write;
  36         fbdev->buffer_write++;
  37         if (fbdev->buffer_write >= fbdev->buffer_count)
  38                 fbdev->buffer_write = 0;
  39
  40         fbdev->fbvar_new.yoffset = fbdev->fbvar_old.yres * draw_buf;
  41
  42         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  43
  44         return fbdev->buffers[fbdev->buffer_write];
  45 }
  46
  47 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  48 {
  49         int arg = 0;
  50         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  51 }
  52
  53 void vout_fbdev_clear(struct vout_fbdev *fbdev)
  54 {
  55         memset(fbdev->mem, 0, fbdev->mem_size);
  56 }
  57
  58 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int no_dblbuf)
  59 {
  60         struct vout_fbdev *fbdev;
  61         int i, ret;
  62
  63         fbdev = calloc(1, sizeof(*fbdev));
  64         if (fbdev == NULL)
  65                 return NULL;
  66
  67         fbdev->fd = open(fbdev_name, O_RDWR, 0);
  68         if (fbdev->fd == -1) {
  69                 fprintf(stderr, "%s: ", fbdev_name);
  70                 perror("open");
  71                 goto fail_open;
  72         }
  73
  74         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
  75         if (ret == -1) {
  76                 perror("FBIOGET_VSCREENINFO ioctl");
  77                 goto fail;
  78         }
  79
  80         fbdev->fbvar_new = fbdev->fbvar_old;
  81         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_old.xres, fbdev->fbvar_old.yres,
  82                 fbdev->fbvar_old.bits_per_pixel);
  83         *w = fbdev->fbvar_old.xres;
  84         *h = fbdev->fbvar_old.yres;
  85         fbdev->buffer_count = FBDEV_MAX_BUFFERS; // be optimistic
  86         if (no_dblbuf)
  87                 fbdev->buffer_count = 1;
  88
  89         if (fbdev->fbvar_new.bits_per_pixel != 16) {
  90                 printf(" switching to 16bpp\n");
  91                 fbdev->fbvar_new.bits_per_pixel = 16;
  92                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
  93                 if (ret == -1) {
  94                         perror("FBIOPUT_VSCREENINFO ioctl");
  95                         goto fail;
  96                 }
  97         }
  98
  99         if (fbdev->fbvar_new.yres_virtual < fbdev->fbvar_old.yres * fbdev->buffer_count) {
 100                 fbdev->fbvar_new.yres_virtual = fbdev->fbvar_old.yres * fbdev->buffer_count;
 101                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 102                 if (ret == -1) {
 103                         fbdev->buffer_count = 1;
 104                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 105                                         "doublebuffering disabled\n");
 106                 }
 107         }
 108
 109         fbdev->mem_size = *w * *h * 2 * fbdev->buffer_count;
 110         fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 111         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 112                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", fbdev->mem_size);
 113                 fbdev->mem_size = *w * *h * 2;
 114                 fbdev->buffer_count = 1;
 115                 fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 116         }
 117         if (fbdev->mem == MAP_FAILED) {
 118                 perror("mmap framebuffer");
 119                 goto fail;
 120         }
 121         memset(fbdev->mem, 0, fbdev->mem_size);
 122         for (i = 0; i < fbdev->buffer_count; i++)
 123                 fbdev->buffers[i] = (char *)fbdev->mem + i * *w * *h * 2;
 124
 125         // some checks
 126         ret = 0;
 127         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 128         if (ret != 0)
 129                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 130
 131         if (fbdev->buffer_count > 1) {
 132                 fbdev->buffer_write = 0;
 133                 fbdev->fbvar_new.yoffset = fbdev->fbvar_old.yres * (fbdev->buffer_count - 1);
 134                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 135                 if (ret != 0) {
 136                         fbdev->buffer_count = 1;
 137                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 138                 }
 139         }
 140
 141         printf("fbdev initialized.\n");
 142         return fbdev;
 143
 144 fail:
 145         close(fbdev->fd);
 146 fail_open:
 147         free(fbdev);
 148         return NULL;
 149 }
 150
 151 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 152 {
 153         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 154         if (fbdev->mem != MAP_FAILED)
 155                 munmap(fbdev->mem, fbdev->mem_size);
 156         if (fbdev->fd >= 0)
 157                 close(fbdev->fd);
 158         fbdev->mem = NULL;
 159         fbdev->fd = -1;
 160         free(fbdev);
 161 }
 162
 163 #if 0
 164 void *g_screen_ptr;
 165 int main()
 166 {
 167         int w, h;
 168         vout_fbdev_init(&w, &h);
 169         //while (1)
 170         {
 171                 memset(g_screen_ptr, 0xff, fbdev_mem_size / 2);
 172                 plat_video_wait_vsync();
 173                 plat_video_flip();
 174                 memset(g_screen_ptr, 0x00, fbdev_mem_size / 2);
 175                 usleep(8000);
 176 //              plat_video_wait_vsync();
 177                 plat_video_flip();
 178         }
 179 }
 180 #endif