frontend/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 #define FBDEV_MAX_BUFFERS 3
  23
  24 struct vout_fbdev {
  25         int     fd;
  26         void    *mem;
  27         size_t  mem_size;
  28         struct  fb_var_screeninfo fbvar_old;
  29         struct  fb_var_screeninfo fbvar_new;
  30         int     buffer_write;
  31         int     fb_size;
  32         int     buffer_count;
  33         int     top_border, bottom_border;
  34 };
  35
  36 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  37 {
  38         int draw_buf;
  39
  40         if (fbdev->buffer_count < 2)
  41                 return fbdev->mem;
  42
  43         draw_buf = fbdev->buffer_write;
  44         fbdev->buffer_write++;
  45         if (fbdev->buffer_write >= fbdev->buffer_count)
  46                 fbdev->buffer_write = 0;
  47
  48         fbdev->fbvar_new.yoffset =
  49                 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
  50                 fbdev->top_border;
  51
  52         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  53
  54         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
  55 }
  56
  57 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  58 {
  59         int arg = 0;
  60         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  61 }
  62
  63 int vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h,
  64                       int left_border, int right_border, int top_border, int bottom_border, int no_dblbuf)
  65 {
  66         int w_total = left_border + w + right_border;
  67         int h_total = top_border + h + bottom_border;
  68         size_t mem_size;
  69         int ret;
  70
  71         // unblank to be sure the mode is really accepted
  72         ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
  73
  74         if (fbdev->fbvar_new.bits_per_pixel != 16 ||
  75                         w != fbdev->fbvar_new.xres ||
  76                         h != fbdev->fbvar_new.yres ||
  77                         w_total != fbdev->fbvar_new.xres_virtual ||
  78                         h_total > fbdev->fbvar_new.yres_virtual ||
  79                         left_border != fbdev->fbvar_new.xoffset) {
  80                 fbdev->fbvar_new.xres = w;
  81                 fbdev->fbvar_new.yres = h;
  82                 fbdev->fbvar_new.xres_virtual = w_total;
  83                 fbdev->fbvar_new.yres_virtual = h_total;
  84                 fbdev->fbvar_new.xoffset = left_border;
  85                 fbdev->fbvar_new.bits_per_pixel = 16;
  86                 printf(" switching to %dx%d@16\n", w, h);
  87                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
  88                 if (ret == -1) {
  89                         perror("FBIOPUT_VSCREENINFO ioctl");
  90                         return -1;
  91                 }
  92         }
  93
  94         fbdev->buffer_count = FBDEV_MAX_BUFFERS; // be optimistic
  95         if (no_dblbuf)
  96                 fbdev->buffer_count = 1;
  97
  98         if (fbdev->fbvar_new.yres_virtual < h_total * fbdev->buffer_count) {
  99                 fbdev->fbvar_new.yres_virtual = h_total * fbdev->buffer_count;
 100                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 101                 if (ret == -1) {
 102                         fbdev->buffer_count = 1;
 103                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 104                                         "doublebuffering disabled\n");
 105                 }
 106         }
 107
 108         fbdev->fb_size = w_total * h_total * 2;
 109         fbdev->top_border = top_border;
 110         fbdev->bottom_border = bottom_border;
 111
 112         mem_size = fbdev->fb_size * fbdev->buffer_count;
 113         if (fbdev->mem_size >= mem_size)
 114                 return 0;
 115
 116         if (fbdev->mem != NULL)
 117                 munmap(fbdev->mem, fbdev->mem_size);
 118
 119         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 120         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 121                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", fbdev->mem_size);
 122                 fbdev->buffer_count = 1;
 123                 mem_size = fbdev->fb_size;
 124                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 125         }
 126         if (fbdev->mem == MAP_FAILED) {
 127                 fbdev->mem = NULL;
 128                 fbdev->mem_size = 0;
 129                 perror("mmap framebuffer");
 130                 return -1;
 131         }
 132
 133         fbdev->mem_size = mem_size;
 134         return 0;
 135 }
 136
 137 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 138 {
 139         memset(fbdev->mem, 0, fbdev->mem_size);
 140 }
 141
 142 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 143 {
 144         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 145         int i;
 146
 147         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 148                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 149
 150         if (y >= 0 && count > 0)
 151                 for (i = 0; i < fbdev->buffer_count; i++)
 152                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 153 }
 154
 155 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 156 {
 157         return fbdev->fd;
 158 }
 159
 160 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int no_dblbuf)
 161 {
 162         struct vout_fbdev *fbdev;
 163         int req_w, req_h;
 164         int ret;
 165
 166         fbdev = calloc(1, sizeof(*fbdev));
 167         if (fbdev == NULL)
 168                 return NULL;
 169
 170         fbdev->fd = open(fbdev_name, O_RDWR);
 171         if (fbdev->fd == -1) {
 172                 fprintf(stderr, "%s: ", fbdev_name);
 173                 perror("open");
 174                 goto fail_open;
 175         }
 176
 177         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 178         if (ret == -1) {
 179                 perror("FBIOGET_VSCREENINFO ioctl");
 180                 goto fail;
 181         }
 182
 183         fbdev->fbvar_new = fbdev->fbvar_old;
 184
 185         req_w = fbdev->fbvar_new.xres;
 186         if (*w != 0)
 187                 req_w = *w;
 188         req_h = fbdev->fbvar_new.yres;
 189         if (*h != 0)
 190                 req_h = *h;
 191
 192         ret = vout_fbdev_resize(fbdev, req_w, req_h, 0, 0, 0, 0, no_dblbuf);
 193         if (ret != 0)
 194                 goto fail;
 195
 196         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres, fbdev->fbvar_new.yres,
 197                 fbdev->fbvar_new.bits_per_pixel);
 198         *w = fbdev->fbvar_new.xres;
 199         *h = fbdev->fbvar_new.yres;
 200
 201         memset(fbdev->mem, 0, fbdev->mem_size);
 202
 203         // some checks
 204         ret = 0;
 205         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 206         if (ret != 0)
 207                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 208
 209         if (fbdev->buffer_count > 1) {
 210                 fbdev->buffer_write = 0;
 211                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 212                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 213                 if (ret != 0) {
 214                         fbdev->buffer_count = 1;
 215                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 216                 }
 217         }
 218
 219         printf("fbdev initialized.\n");
 220         return fbdev;
 221
 222 fail:
 223         close(fbdev->fd);
 224 fail_open:
 225         free(fbdev);
 226         return NULL;
 227 }
 228
 229 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 230 {
 231         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 232         if (fbdev->mem != MAP_FAILED)
 233                 munmap(fbdev->mem, fbdev->mem_size);
 234         if (fbdev->fd >= 0)
 235                 close(fbdev->fd);
 236         fbdev->mem = NULL;
 237         fbdev->fd = -1;
 238         free(fbdev);
 239 }
 240