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 #define PFX "fbdev: "
  26
  27 struct vout_fbdev {
  28         int     fd;
  29         void    *mem;
  30         size_t  mem_size;
  31         struct  fb_var_screeninfo fbvar_old;
  32         struct  fb_var_screeninfo fbvar_new;
  33         int     buffer_write;
  34         int     fb_size;
  35         int     buffer_count;
  36         int     top_border, bottom_border;
  37         void    *mem_saved;
  38         size_t  mem_saved_size;
  39 };
  40
  41 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  42 {
  43         int draw_buf;
  44
  45         if (fbdev->buffer_count < 2)
  46                 return fbdev->mem;
  47
  48         draw_buf = fbdev->buffer_write;
  49         fbdev->buffer_write++;
  50         if (fbdev->buffer_write >= fbdev->buffer_count)
  51                 fbdev->buffer_write = 0;
  52
  53         fbdev->fbvar_new.yoffset =
  54                 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
  55                 fbdev->top_border;
  56
  57         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  58
  59         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
  60 }
  61
  62 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  63 {
  64         int arg = 0;
  65         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  66 }
  67
  68 /* it is recommended to call vout_fbdev_clear() before this */
  69 void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
  70                       int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
  71 {
  72         int w_total = left_border + w + right_border;
  73         int h_total = top_border + h + bottom_border;
  74         size_t mem_size;
  75         int ret;
  76
  77         // unblank to be sure the mode is really accepted
  78         ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
  79
  80         if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  81                         fbdev->fbvar_new.xres != w ||
  82                         fbdev->fbvar_new.yres != h ||
  83                         fbdev->fbvar_new.xres_virtual != w_total||
  84                         fbdev->fbvar_new.yres_virtual < h_total ||
  85                         fbdev->fbvar_new.xoffset != left_border ||
  86                         fbdev->buffer_count != buffer_cnt)
  87         {
  88                 if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  89                                 w != fbdev->fbvar_new.xres || h != fbdev->fbvar_new.yres)
  90                         printf(PFX "switching to %dx%d@%d\n", w, h, bpp);
  91
  92                 fbdev->fbvar_new.xres = w;
  93                 fbdev->fbvar_new.yres = h;
  94                 fbdev->fbvar_new.xres_virtual = w_total;
  95                 fbdev->fbvar_new.yres_virtual = h_total * buffer_cnt;
  96                 fbdev->fbvar_new.xoffset = left_border;
  97                 fbdev->fbvar_new.yoffset = top_border;
  98                 fbdev->fbvar_new.bits_per_pixel = bpp;
  99                 fbdev->fbvar_new.nonstd = 0; // can set YUV here on omapfb
 100                 fbdev->buffer_count = buffer_cnt;
 101                 fbdev->buffer_write = buffer_cnt > 1 ? 1 : 0;
 102
 103                 // seems to help a bit to avoid glitches
 104                 vout_fbdev_wait_vsync(fbdev);
 105
 106                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 107                 if (ret == -1) {
 108                         // retry with no multibuffering
 109                         fbdev->fbvar_new.yres_virtual = h_total;
 110                         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 111                         if (ret == -1) {
 112                                 perror(PFX "FBIOPUT_VSCREENINFO ioctl");
 113                                 return NULL;
 114                         }
 115                         fbdev->buffer_count = 1;
 116                         fbdev->buffer_write = 0;
 117                         fprintf(stderr, PFX "Warning: failed to increase virtual resolution, "
 118                                         "multibuffering disabled\n");
 119                 }
 120
 121         }
 122
 123         fbdev->fb_size = w_total * h_total * bpp / 8;
 124         fbdev->top_border = top_border;
 125         fbdev->bottom_border = bottom_border;
 126
 127         mem_size = fbdev->fb_size * fbdev->buffer_count;
 128         if (fbdev->mem_size >= mem_size)
 129                 goto out;
 130
 131         if (fbdev->mem != NULL)
 132                 munmap(fbdev->mem, fbdev->mem_size);
 133
 134         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 135         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 136                 fprintf(stderr, PFX "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 137                 fbdev->buffer_count = 1;
 138                 fbdev->buffer_write = 0;
 139                 mem_size = fbdev->fb_size;
 140                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 141         }
 142         if (fbdev->mem == MAP_FAILED) {
 143                 fbdev->mem = NULL;
 144                 fbdev->mem_size = 0;
 145                 perror(PFX "mmap framebuffer");
 146                 return NULL;
 147         }
 148
 149         fbdev->mem_size = mem_size;
 150
 151 out:
 152         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 153 }
 154
 155 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 156 {
 157         memset(fbdev->mem, 0, fbdev->mem_size);
 158 }
 159
 160 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 161 {
 162         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 163         int i;
 164
 165         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 166                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 167
 168         if (y >= 0 && count > 0)
 169                 for (i = 0; i < fbdev->buffer_count; i++)
 170                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 171 }
 172
 173 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 174 {
 175         return fbdev->fd;
 176 }
 177
 178 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 179 {
 180         struct vout_fbdev *fbdev;
 181         int req_w, req_h;
 182         void *pret;
 183         int ret;
 184
 185         fbdev = calloc(1, sizeof(*fbdev));
 186         if (fbdev == NULL)
 187                 return NULL;
 188
 189         fbdev->fd = open(fbdev_name, O_RDWR);
 190         if (fbdev->fd == -1) {
 191                 fprintf(stderr, PFX "%s: ", fbdev_name);
 192                 perror("open");
 193                 goto fail_open;
 194         }
 195
 196         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 197         if (ret == -1) {
 198                 perror(PFX "FBIOGET_VSCREENINFO ioctl");
 199                 goto fail;
 200         }
 201
 202         fbdev->fbvar_new = fbdev->fbvar_old;
 203
 204         req_w = fbdev->fbvar_new.xres;
 205         if (*w != 0)
 206                 req_w = *w;
 207         req_h = fbdev->fbvar_new.yres;
 208         if (*h != 0)
 209                 req_h = *h;
 210
 211         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 212         if (pret == NULL)
 213                 goto fail;
 214
 215         printf(PFX "%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres,
 216                 fbdev->fbvar_new.yres, fbdev->fbvar_new.bits_per_pixel);
 217         *w = fbdev->fbvar_new.xres;
 218         *h = fbdev->fbvar_new.yres;
 219
 220         memset(fbdev->mem, 0, fbdev->mem_size);
 221
 222         // some checks
 223         ret = 0;
 224         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 225         if (ret != 0)
 226                 fprintf(stderr, PFX "Warning: vsync doesn't seem to be supported\n");
 227
 228         if (fbdev->buffer_count > 1) {
 229                 fbdev->buffer_write = 0;
 230                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 231                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 232                 if (ret != 0) {
 233                         fbdev->buffer_count = 1;
 234                         fprintf(stderr, PFX "Warning: can't pan display, doublebuffering disabled\n");
 235                 }
 236         }
 237
 238         printf("fbdev initialized.\n");
 239         return fbdev;
 240
 241 fail:
 242         close(fbdev->fd);
 243 fail_open:
 244         free(fbdev);
 245         return NULL;
 246 }
 247
 248 static void vout_fbdev_release(struct vout_fbdev *fbdev)
 249 {
 250         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 251         if (fbdev->mem != MAP_FAILED)
 252                 munmap(fbdev->mem, fbdev->mem_size);
 253         fbdev->mem = NULL;
 254 }
 255
 256 int vout_fbdev_save(struct vout_fbdev *fbdev)
 257 {
 258         void *tmp;
 259
 260         if (fbdev == NULL || fbdev->mem == NULL || fbdev->mem == MAP_FAILED) {
 261                 fprintf(stderr, PFX "bad args for save\n");
 262                 return -1;
 263         }
 264
 265         if (fbdev->mem_saved_size < fbdev->mem_size) {
 266                 tmp = realloc(fbdev->mem_saved, fbdev->mem_size);
 267                 if (tmp == NULL)
 268                         return -1;
 269                 fbdev->mem_saved = tmp;
 270         }
 271         memcpy(fbdev->mem_saved, fbdev->mem, fbdev->mem_size);
 272         fbdev->mem_saved_size = fbdev->mem_size;
 273
 274         vout_fbdev_release(fbdev);
 275         return 0;
 276 }
 277
 278 int vout_fbdev_restore(struct vout_fbdev *fbdev)
 279 {
 280         int ret;
 281
 282         if (fbdev == NULL || fbdev->mem != NULL) {
 283                 fprintf(stderr, PFX "bad args/state for restore\n");
 284                 return -1;
 285         }
 286
 287         fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 288         if (fbdev->mem == MAP_FAILED) {
 289                 perror(PFX "restore: memory restore failed");
 290                 return -1;
 291         }
 292         memcpy(fbdev->mem, fbdev->mem_saved, fbdev->mem_size);
 293
 294         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 295         if (ret == -1) {
 296                 perror(PFX "restore: FBIOPUT_VSCREENINFO");
 297                 return -1;
 298         }
 299
 300         return 0;
 301 }
 302
 303 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 304 {
 305         vout_fbdev_release(fbdev);
 306         if (fbdev->fd >= 0)
 307                 close(fbdev->fd);
 308         fbdev->fd = -1;
 309         free(fbdev);
 310 }
 311