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->fbvar_new.nonstd = 0; // can set YUV here on omapfb
  96                 fbdev->buffer_count = buffer_cnt;
  97                 fbdev->buffer_write = 1;
  98
  99                 // seems to help a bit to avoid glitches
 100                 vout_fbdev_wait_vsync(fbdev);
 101
 102                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 103                 if (ret == -1) {
 104                         // retry with no multibuffering
 105                         fbdev->fbvar_new.yres_virtual = h_total;
 106                         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 107                         if (ret == -1) {
 108                                 perror("FBIOPUT_VSCREENINFO ioctl");
 109                                 return NULL;
 110                         }
 111                         fbdev->buffer_count = 1;
 112                         fbdev->buffer_write = 0;
 113                         fprintf(stderr, "Warning: failed to increase virtual resolution, "
 114                                         "multibuffering disabled\n");
 115                 }
 116
 117         }
 118
 119         fbdev->fb_size = w_total * h_total * bpp / 8;
 120         fbdev->top_border = top_border;
 121         fbdev->bottom_border = bottom_border;
 122
 123         mem_size = fbdev->fb_size * fbdev->buffer_count;
 124         if (fbdev->mem_size >= mem_size)
 125                 goto out;
 126
 127         if (fbdev->mem != NULL)
 128                 munmap(fbdev->mem, fbdev->mem_size);
 129
 130         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 131         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 132                 fprintf(stderr, "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 133                 fbdev->buffer_count = 1;
 134                 fbdev->buffer_write = 0;
 135                 mem_size = fbdev->fb_size;
 136                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 137         }
 138         if (fbdev->mem == MAP_FAILED) {
 139                 fbdev->mem = NULL;
 140                 fbdev->mem_size = 0;
 141                 perror("mmap framebuffer");
 142                 return NULL;
 143         }
 144
 145         fbdev->mem_size = mem_size;
 146
 147 out:
 148         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 149 }
 150
 151 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 152 {
 153         memset(fbdev->mem, 0, fbdev->mem_size);
 154 }
 155
 156 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 157 {
 158         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 159         int i;
 160
 161         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 162                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 163
 164         if (y >= 0 && count > 0)
 165                 for (i = 0; i < fbdev->buffer_count; i++)
 166                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 167 }
 168
 169 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 170 {
 171         return fbdev->fd;
 172 }
 173
 174 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 175 {
 176         struct vout_fbdev *fbdev;
 177         int req_w, req_h;
 178         void *pret;
 179         int ret;
 180
 181         fbdev = calloc(1, sizeof(*fbdev));
 182         if (fbdev == NULL)
 183                 return NULL;
 184
 185         fbdev->fd = open(fbdev_name, O_RDWR);
 186         if (fbdev->fd == -1) {
 187                 fprintf(stderr, "%s: ", fbdev_name);
 188                 perror("open");
 189                 goto fail_open;
 190         }
 191
 192         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 193         if (ret == -1) {
 194                 perror("FBIOGET_VSCREENINFO ioctl");
 195                 goto fail;
 196         }
 197
 198         fbdev->fbvar_new = fbdev->fbvar_old;
 199
 200         req_w = fbdev->fbvar_new.xres;
 201         if (*w != 0)
 202                 req_w = *w;
 203         req_h = fbdev->fbvar_new.yres;
 204         if (*h != 0)
 205                 req_h = *h;
 206
 207         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 208         if (pret == NULL)
 209                 goto fail;
 210
 211         printf("%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres, fbdev->fbvar_new.yres,
 212                 fbdev->fbvar_new.bits_per_pixel);
 213         *w = fbdev->fbvar_new.xres;
 214         *h = fbdev->fbvar_new.yres;
 215
 216         memset(fbdev->mem, 0, fbdev->mem_size);
 217
 218         // some checks
 219         ret = 0;
 220         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 221         if (ret != 0)
 222                 fprintf(stderr, "Warning: vsync doesn't seem to be supported\n");
 223
 224         if (fbdev->buffer_count > 1) {
 225                 fbdev->buffer_write = 0;
 226                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 227                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 228                 if (ret != 0) {
 229                         fbdev->buffer_count = 1;
 230                         fprintf(stderr, "Warning: can't pan display, doublebuffering disabled\n");
 231                 }
 232         }
 233
 234         printf("fbdev initialized.\n");
 235         return fbdev;
 236
 237 fail:
 238         close(fbdev->fd);
 239 fail_open:
 240         free(fbdev);
 241         return NULL;
 242 }
 243
 244 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 245 {
 246         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 247         if (fbdev->mem != MAP_FAILED)
 248                 munmap(fbdev->mem, fbdev->mem_size);
 249         if (fbdev->fd >= 0)
 250                 close(fbdev->fd);
 251         fbdev->mem = NULL;
 252         fbdev->fd = -1;
 253         free(fbdev);
 254 }
 255