linux/fbdev.c

   1 /*
   2  * (C) Gražvydas "notaz" Ignotas, 2009-2010
   3  *
   4  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
   5  * See the COPYING file in the top-level directory.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <fcntl.h>
  14 #include <sys/ioctl.h>
  15 #include <sys/mman.h>
  16 #include <unistd.h>
  17 #include <linux/fb.h>
  18 #include <linux/matroxfb.h>
  19
  20 #include "fbdev.h"
  21
  22 struct vout_fbdev {
  23         int     fd;
  24         void    *mem;
  25         size_t  mem_size;
  26         struct  fb_var_screeninfo fbvar_old;
  27         struct  fb_var_screeninfo fbvar_new;
  28         int     buffer_write;
  29         int     fb_size;
  30         int     buffer_count;
  31         int     top_border, bottom_border;
  32 };
  33
  34 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  35 {
  36         int draw_buf;
  37
  38         if (fbdev->buffer_count < 2)
  39                 return fbdev->mem;
  40
  41         draw_buf = fbdev->buffer_write;
  42         fbdev->buffer_write++;
  43         if (fbdev->buffer_write >= fbdev->buffer_count)
  44                 fbdev->buffer_write = 0;
  45
  46         fbdev->fbvar_new.yoffset =
  47                 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
  48                 fbdev->top_border;
  49
  50         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  51
  52         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
  53 }
  54
  55 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  56 {
  57         int arg = 0;
  58         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  59 }
  60
  61 int vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
  62                       int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
  63 {
  64         int w_total = left_border + w + right_border;
  65         int h_total = top_border + h + bottom_border;
  66         size_t mem_size;
  67         int ret;
  68
  69         // unblank to be sure the mode is really accepted
  70         ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
  71
  72         if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  73                         w != fbdev->fbvar_new.xres ||
  74                         h != fbdev->fbvar_new.yres ||
  75                         w_total != fbdev->fbvar_new.xres_virtual ||
  76                         h_total > fbdev->fbvar_new.yres_virtual ||
  77                         left_border != fbdev->fbvar_new.xoffset) {
  78                 fbdev->fbvar_new.xres = w;
  79                 fbdev->fbvar_new.yres = h;
  80                 fbdev->fbvar_new.xres_virtual = w_total;
  81                 fbdev->fbvar_new.yres_virtual = h_total;
  82                 fbdev->fbvar_new.xoffset = left_border;
  83                 fbdev->fbvar_new.bits_per_pixel = bpp;
  84                 printf(" switching to %dx%d@%d\n", w, h, bpp);
  85                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
  86                 if (ret == -1) {
  87                         perror("FBIOPUT_VSCREENINFO ioctl");
  88                         return -1;
  89                 }
  90         }
  91
  92         fbdev->buffer_count = buffer_cnt;
  93
  94         if (fbdev->fbvar_new.yres_virtual < h_total * fbdev->buffer_count) {
  95                 fbdev->fbvar_new.yres_virtual = h_total * fbdev->buffer_count;
  96                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
  97                 if (ret == -1) {
  98                         fbdev->buffer_count = 1;
  99                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 100                                         "doublebuffering disabled\n");
 101                 }
 102         }
 103
 104         fbdev->fb_size = w_total * h_total * bpp / 8;
 105         fbdev->top_border = top_border;
 106         fbdev->bottom_border = bottom_border;
 107
 108         mem_size = fbdev->fb_size * fbdev->buffer_count;
 109         if (fbdev->mem_size >= mem_size)
 110                 return 0;
 111
 112         if (fbdev->mem != NULL)
 113                 munmap(fbdev->mem, fbdev->mem_size);
 114
 115         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 116         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 117                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", fbdev->mem_size);
 118                 fbdev->buffer_count = 1;
 119                 mem_size = fbdev->fb_size;
 120                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 121         }
 122         if (fbdev->mem == MAP_FAILED) {
 123                 fbdev->mem = NULL;
 124                 fbdev->mem_size = 0;
 125                 perror("mmap framebuffer");
 126                 return -1;
 127         }
 128
 129         fbdev->mem_size = mem_size;
 130         return 0;
 131 }
 132
 133 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 134 {
 135         memset(fbdev->mem, 0, fbdev->mem_size);
 136 }
 137
 138 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 139 {
 140         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 141         int i;
 142
 143         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 144                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 145
 146         if (y >= 0 && count > 0)
 147                 for (i = 0; i < fbdev->buffer_count; i++)
 148                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 149 }
 150
 151 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 152 {
 153         return fbdev->fd;
 154 }
 155
 156 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 157 {
 158         struct vout_fbdev *fbdev;
 159         int req_w, req_h;
 160         int ret;
 161
 162         fbdev = calloc(1, sizeof(*fbdev));
 163         if (fbdev == NULL)
 164                 return NULL;
 165
 166         fbdev->fd = open(fbdev_name, O_RDWR);
 167         if (fbdev->fd == -1) {
 168                 fprintf(stderr, "%s: ", fbdev_name);
 169                 perror("open");
 170                 goto fail_open;
 171         }
 172
 173         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 174         if (ret == -1) {
 175                 perror("FBIOGET_VSCREENINFO ioctl");
 176                 goto fail;
 177         }
 178
 179         fbdev->fbvar_new = fbdev->fbvar_old;
 180
 181         req_w = fbdev->fbvar_new.xres;
 182         if (*w != 0)
 183                 req_w = *w;
 184         req_h = fbdev->fbvar_new.yres;
 185         if (*h != 0)
 186                 req_h = *h;
 187
 188         ret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 189         if (ret != 0)
 190                 goto fail;
 191
 192         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres, fbdev->fbvar_new.yres,
 193                 fbdev->fbvar_new.bits_per_pixel);
 194         *w = fbdev->fbvar_new.xres;
 195         *h = fbdev->fbvar_new.yres;
 196
 197         memset(fbdev->mem, 0, fbdev->mem_size);
 198
 199         // some checks
 200         ret = 0;
 201         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 202         if (ret != 0)
 203                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 204
 205         if (fbdev->buffer_count > 1) {
 206                 fbdev->buffer_write = 0;
 207                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 208                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 209                 if (ret != 0) {
 210                         fbdev->buffer_count = 1;
 211                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 212                 }
 213         }
 214
 215         printf("fbdev initialized.\n");
 216         return fbdev;
 217
 218 fail:
 219         close(fbdev->fd);
 220 fail_open:
 221         free(fbdev);
 222         return NULL;
 223 }
 224
 225 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 226 {
 227         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 228         if (fbdev->mem != MAP_FAILED)
 229                 munmap(fbdev->mem, fbdev->mem_size);
 230         if (fbdev->fd >= 0)
 231                 close(fbdev->fd);
 232         fbdev->mem = NULL;
 233         fbdev->fd = -1;
 234         free(fbdev);
 235 }
 236