frontend/linux/fbdev.c

   1 /*
   2  * (C) Gražvydas "notaz" Ignotas, 2009-2010
   3  *
   4  * This work is licensed under the terms of any of these licenses
   5  * (at your option):
   6  *  - GNU GPL, version 2 or later.
   7  *  - GNU LGPL, version 2.1 or later.
   8  * See the COPYING file in the top-level directory.
   9  */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include <fcntl.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/mman.h>
  19 #include <unistd.h>
  20 #include <linux/fb.h>
  21 #include <linux/matroxfb.h>
  22
  23 #include "fbdev.h"
  24
  25 struct vout_fbdev {
  26         int     fd;
  27         void    *mem;
  28         size_t  mem_size;
  29         struct  fb_var_screeninfo fbvar_old;
  30         struct  fb_var_screeninfo fbvar_new;
  31         int     buffer_write;
  32         int     fb_size;
  33         int     buffer_count;
  34         int     top_border, bottom_border;
  35 };
  36
  37 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  38 {
  39         int draw_buf;
  40
  41         if (fbdev->buffer_count < 2)
  42                 return fbdev->mem;
  43
  44         draw_buf = fbdev->buffer_write;
  45         fbdev->buffer_write++;
  46         if (fbdev->buffer_write >= fbdev->buffer_count)
  47                 fbdev->buffer_write = 0;
  48
  49         fbdev->fbvar_new.yoffset =
  50                 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
  51                 fbdev->top_border;
  52
  53         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  54
  55         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
  56 }
  57
  58 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  59 {
  60         int arg = 0;
  61         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  62 }
  63
  64 /* it is recommended to call vout_fbdev_clear() before this */
  65 void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
  66                       int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
  67 {
  68         int w_total = left_border + w + right_border;
  69         int h_total = top_border + h + bottom_border;
  70         size_t mem_size;
  71         int ret;
  72
  73         // unblank to be sure the mode is really accepted
  74         ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
  75
  76         if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  77                         w != fbdev->fbvar_new.xres ||
  78                         h != fbdev->fbvar_new.yres ||
  79                         w_total != fbdev->fbvar_new.xres_virtual ||
  80                         h_total > fbdev->fbvar_new.yres_virtual ||
  81                         left_border != fbdev->fbvar_new.xoffset) {
  82                 fbdev->fbvar_new.xres = w;
  83                 fbdev->fbvar_new.yres = h;
  84                 fbdev->fbvar_new.xres_virtual = w_total;
  85                 fbdev->fbvar_new.yres_virtual = h_total;
  86                 fbdev->fbvar_new.xoffset = left_border;
  87                 fbdev->fbvar_new.yoffset = top_border;
  88                 fbdev->fbvar_new.bits_per_pixel = bpp;
  89                 printf(" switching to %dx%d@%d\n", w, h, bpp);
  90
  91                 // seems to help a bit to avoid glitches
  92                 vout_fbdev_wait_vsync(fbdev);
  93
  94                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
  95                 if (ret == -1) {
  96                         perror("FBIOPUT_VSCREENINFO ioctl");
  97                         return NULL;
  98                 }
  99
 100                 fbdev->buffer_write = 1;
 101         }
 102
 103         fbdev->buffer_count = buffer_cnt;
 104
 105         if (fbdev->fbvar_new.yres_virtual < h_total * fbdev->buffer_count) {
 106                 fbdev->fbvar_new.yres_virtual = h_total * fbdev->buffer_count;
 107                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 108                 if (ret == -1) {
 109                         fbdev->buffer_count = 1;
 110                         fbdev->buffer_write = 0;
 111                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 112                                         "doublebuffering disabled\n");
 113                 }
 114         }
 115
 116         fbdev->fb_size = w_total * h_total * bpp / 8;
 117         fbdev->top_border = top_border;
 118         fbdev->bottom_border = bottom_border;
 119
 120         mem_size = fbdev->fb_size * fbdev->buffer_count;
 121         if (fbdev->mem_size >= mem_size)
 122                 goto out;
 123
 124         if (fbdev->mem != NULL)
 125                 munmap(fbdev->mem, fbdev->mem_size);
 126
 127         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 128         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 129                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 130                 fbdev->buffer_count = 1;
 131                 fbdev->buffer_write = 0;
 132                 mem_size = fbdev->fb_size;
 133                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 134         }
 135         if (fbdev->mem == MAP_FAILED) {
 136                 fbdev->mem = NULL;
 137                 fbdev->mem_size = 0;
 138                 perror("mmap framebuffer");
 139                 return NULL;
 140         }
 141
 142         fbdev->mem_size = mem_size;
 143
 144 out:
 145         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 146 }
 147
 148 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 149 {
 150         memset(fbdev->mem, 0, fbdev->mem_size);
 151 }
 152
 153 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 154 {
 155         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 156         int i;
 157
 158         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 159                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 160
 161         if (y >= 0 && count > 0)
 162                 for (i = 0; i < fbdev->buffer_count; i++)
 163                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 164 }
 165
 166 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 167 {
 168         return fbdev->fd;
 169 }
 170
 171 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 172 {
 173         struct vout_fbdev *fbdev;
 174         int req_w, req_h;
 175         void *pret;
 176         int ret;
 177
 178         fbdev = calloc(1, sizeof(*fbdev));
 179         if (fbdev == NULL)
 180                 return NULL;
 181
 182         fbdev->fd = open(fbdev_name, O_RDWR);
 183         if (fbdev->fd == -1) {
 184                 fprintf(stderr, "%s: ", fbdev_name);
 185                 perror("open");
 186                 goto fail_open;
 187         }
 188
 189         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 190         if (ret == -1) {
 191                 perror("FBIOGET_VSCREENINFO ioctl");
 192                 goto fail;
 193         }
 194
 195         fbdev->fbvar_new = fbdev->fbvar_old;
 196
 197         req_w = fbdev->fbvar_new.xres;
 198         if (*w != 0)
 199                 req_w = *w;
 200         req_h = fbdev->fbvar_new.yres;
 201         if (*h != 0)
 202                 req_h = *h;
 203
 204         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 205         if (pret == NULL)
 206                 goto fail;
 207
 208         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres, fbdev->fbvar_new.yres,
 209                 fbdev->fbvar_new.bits_per_pixel);
 210         *w = fbdev->fbvar_new.xres;
 211         *h = fbdev->fbvar_new.yres;
 212
 213         memset(fbdev->mem, 0, fbdev->mem_size);
 214
 215         // some checks
 216         ret = 0;
 217         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 218         if (ret != 0)
 219                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 220
 221         if (fbdev->buffer_count > 1) {
 222                 fbdev->buffer_write = 0;
 223                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 224                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 225                 if (ret != 0) {
 226                         fbdev->buffer_count = 1;
 227                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 228                 }
 229         }
 230
 231         printf("fbdev initialized.\n");
 232         return fbdev;
 233
 234 fail:
 235         close(fbdev->fd);
 236 fail_open:
 237         free(fbdev);
 238         return NULL;
 239 }
 240
 241 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 242 {
 243         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 244         if (fbdev->mem != MAP_FAILED)
 245                 munmap(fbdev->mem, fbdev->mem_size);
 246         if (fbdev->fd >= 0)
 247                 close(fbdev->fd);
 248         fbdev->mem = NULL;
 249         fbdev->fd = -1;
 250         free(fbdev);
 251 }
 252