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                         fbdev->fbvar_new.xres != w ||
  78                         fbdev->fbvar_new.yres != h ||
  79                         fbdev->fbvar_new.xres_virtual != w_total||
  80                         fbdev->fbvar_new.yres_virtual < h_total ||
  81                         fbdev->fbvar_new.xoffset != left_border ||
  82                         fbdev->buffer_count != buffer_cnt)
  83         {
  84                 if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  85                                 w != fbdev->fbvar_new.xres || h != fbdev->fbvar_new.yres)
  86                         printf(" switching to %dx%d@%d\n", w, h, bpp);
  87
  88                 fbdev->fbvar_new.xres = w;
  89                 fbdev->fbvar_new.yres = h;
  90                 fbdev->fbvar_new.xres_virtual = w_total;
  91                 fbdev->fbvar_new.yres_virtual = h_total * buffer_cnt;
  92                 fbdev->fbvar_new.xoffset = left_border;
  93                 fbdev->fbvar_new.yoffset = top_border;
  94                 fbdev->fbvar_new.bits_per_pixel = bpp;
  95                 fbdev->buffer_count = buffer_cnt;
  96                 fbdev->buffer_write = 1;
  97
  98                 // seems to help a bit to avoid glitches
  99                 vout_fbdev_wait_vsync(fbdev);
 100
 101                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 102                 if (ret == -1) {
 103                         // retry with no multibuffering
 104                         fbdev->fbvar_new.yres_virtual = h_total;
 105                         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 106                         if (ret == -1) {
 107                                 perror("FBIOPUT_VSCREENINFO ioctl");
 108                                 return NULL;
 109                         }
 110                         fbdev->buffer_count = 1;
 111                         fbdev->buffer_write = 0;
 112                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 113                                         "multibuffering disabled\n");
 114                 }
 115
 116         }
 117
 118         fbdev->fb_size = w_total * h_total * bpp / 8;
 119         fbdev->top_border = top_border;
 120         fbdev->bottom_border = bottom_border;
 121
 122         mem_size = fbdev->fb_size * fbdev->buffer_count;
 123         if (fbdev->mem_size >= mem_size)
 124                 goto out;
 125
 126         if (fbdev->mem != NULL)
 127                 munmap(fbdev->mem, fbdev->mem_size);
 128
 129         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 130         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 131                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 132                 fbdev->buffer_count = 1;
 133                 fbdev->buffer_write = 0;
 134                 mem_size = fbdev->fb_size;
 135                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 136         }
 137         if (fbdev->mem == MAP_FAILED) {
 138                 fbdev->mem = NULL;
 139                 fbdev->mem_size = 0;
 140                 perror("mmap framebuffer");
 141                 return NULL;
 142         }
 143
 144         fbdev->mem_size = mem_size;
 145
 146 out:
 147         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 148 }
 149
 150 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 151 {
 152         memset(fbdev->mem, 0, fbdev->mem_size);
 153 }
 154
 155 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 156 {
 157         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 158         int i;
 159
 160         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 161                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 162
 163         if (y >= 0 && count > 0)
 164                 for (i = 0; i < fbdev->buffer_count; i++)
 165                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 166 }
 167
 168 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 169 {
 170         return fbdev->fd;
 171 }
 172
 173 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 174 {
 175         struct vout_fbdev *fbdev;
 176         int req_w, req_h;
 177         void *pret;
 178         int ret;
 179
 180         fbdev = calloc(1, sizeof(*fbdev));
 181         if (fbdev == NULL)
 182                 return NULL;
 183
 184         fbdev->fd = open(fbdev_name, O_RDWR);
 185         if (fbdev->fd == -1) {
 186                 fprintf(stderr, "%s: ", fbdev_name);
 187                 perror("open");
 188                 goto fail_open;
 189         }
 190
 191         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 192         if (ret == -1) {
 193                 perror("FBIOGET_VSCREENINFO ioctl");
 194                 goto fail;
 195         }
 196
 197         fbdev->fbvar_new = fbdev->fbvar_old;
 198
 199         req_w = fbdev->fbvar_new.xres;
 200         if (*w != 0)
 201                 req_w = *w;
 202         req_h = fbdev->fbvar_new.yres;
 203         if (*h != 0)
 204                 req_h = *h;
 205
 206         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 207         if (pret == NULL)
 208                 goto fail;
 209
 210         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres, fbdev->fbvar_new.yres,
 211                 fbdev->fbvar_new.bits_per_pixel);
 212         *w = fbdev->fbvar_new.xres;
 213         *h = fbdev->fbvar_new.yres;
 214
 215         memset(fbdev->mem, 0, fbdev->mem_size);
 216
 217         // some checks
 218         ret = 0;
 219         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 220         if (ret != 0)
 221                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 222
 223         if (fbdev->buffer_count > 1) {
 224                 fbdev->buffer_write = 0;
 225                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 226                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 227                 if (ret != 0) {
 228                         fbdev->buffer_count = 1;
 229                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 230                 }
 231         }
 232
 233         printf("fbdev initialized.\n");
 234         return fbdev;
 235
 236 fail:
 237         close(fbdev->fd);
 238 fail_open:
 239         free(fbdev);
 240         return NULL;
 241 }
 242
 243 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 244 {
 245         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 246         if (fbdev->mem != MAP_FAILED)
 247                 munmap(fbdev->mem, fbdev->mem_size);
 248         if (fbdev->fd >= 0)
 249                 close(fbdev->fd);
 250         fbdev->mem = NULL;
 251         fbdev->fd = -1;
 252         free(fbdev);
 253 }
 254