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  *  - MAME license.
   9  * See the COPYING file in the top-level directory.
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18 #include <sys/ioctl.h>
  19 #include <sys/mman.h>
  20 #include <unistd.h>
  21 #include <linux/fb.h>
  22 #include <linux/matroxfb.h>
  23
  24 #include "fbdev.h"
  25
  26 #define PFX "fbdev: "
  27
  28 struct vout_fbdev {
  29         int     fd;
  30         void    *mem;
  31         size_t  mem_size;
  32         struct  fb_var_screeninfo fbvar_old;
  33         struct  fb_var_screeninfo fbvar_new;
  34         int     buffer_write;
  35         int     fb_size;
  36         int     buffer_count;
  37         int     top_border, bottom_border;
  38         void    *mem_saved;
  39         size_t  mem_saved_size;
  40 };
  41
  42 void *vout_fbdev_flip(struct vout_fbdev *fbdev)
  43 {
  44         int draw_buf;
  45
  46         if (fbdev->buffer_count < 2)
  47                 return fbdev->mem;
  48
  49         draw_buf = fbdev->buffer_write;
  50         fbdev->buffer_write++;
  51         if (fbdev->buffer_write >= fbdev->buffer_count)
  52                 fbdev->buffer_write = 0;
  53
  54         fbdev->fbvar_new.yoffset =
  55                 (fbdev->top_border + fbdev->fbvar_new.yres + fbdev->bottom_border) * draw_buf +
  56                 fbdev->top_border;
  57
  58         ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
  59
  60         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
  61 }
  62
  63 void vout_fbdev_wait_vsync(struct vout_fbdev *fbdev)
  64 {
  65         int arg = 0;
  66         ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &arg);
  67 }
  68
  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,
  71         int buffer_cnt, int first_write_to_front)
  72 {
  73         int w_total = left_border + w + right_border;
  74         int h_total = top_border + h + bottom_border;
  75         size_t mem_size;
  76         int ret;
  77
  78         // unblank to be sure the mode is really accepted
  79         ioctl(fbdev->fd, FBIOBLANK, FB_BLANK_UNBLANK);
  80
  81         if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  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->buffer_count != buffer_cnt)
  88         {
  89                 if (fbdev->fbvar_new.bits_per_pixel != bpp ||
  90                                 w != fbdev->fbvar_new.xres || h != fbdev->fbvar_new.yres)
  91                         printf(PFX "switching to %dx%d@%d\n", w, h, bpp);
  92
  93                 fbdev->fbvar_new.xres = w;
  94                 fbdev->fbvar_new.yres = h;
  95                 fbdev->fbvar_new.xres_virtual = w_total;
  96                 fbdev->fbvar_new.yres_virtual = h_total * buffer_cnt;
  97                 fbdev->fbvar_new.xoffset = left_border;
  98                 fbdev->fbvar_new.yoffset = top_border;
  99                 fbdev->fbvar_new.bits_per_pixel = bpp;
 100                 fbdev->fbvar_new.nonstd = 0; // can set YUV here on omapfb
 101                 fbdev->buffer_count = buffer_cnt;
 102                 fbdev->buffer_write = buffer_cnt > 1 ? 1 : 0;
 103                 if (first_write_to_front)
 104                         fbdev->buffer_write = 0;
 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                 // omap is still using the old mode until vsync,
 122                 // if the caller starts to write now we may get garbage on screen
 123                 vout_fbdev_wait_vsync(fbdev);
 124         }
 125
 126         fbdev->fb_size = w_total * h_total * bpp / 8;
 127         fbdev->top_border = top_border;
 128         fbdev->bottom_border = bottom_border;
 129
 130         mem_size = fbdev->fb_size * fbdev->buffer_count;
 131         if (fbdev->mem_size >= mem_size)
 132                 goto out;
 133
 134         if (fbdev->mem != NULL)
 135                 munmap(fbdev->mem, fbdev->mem_size);
 136
 137         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 138         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 139                 fprintf(stderr, PFX "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 140                 fbdev->buffer_count = 1;
 141                 fbdev->buffer_write = 0;
 142                 mem_size = fbdev->fb_size;
 143                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 144         }
 145         if (fbdev->mem == MAP_FAILED) {
 146                 fbdev->mem = NULL;
 147                 fbdev->mem_size = 0;
 148                 perror(PFX "mmap framebuffer");
 149                 return NULL;
 150         }
 151
 152         fbdev->mem_size = mem_size;
 153
 154 out:
 155         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 156 }
 157
 158 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 159 {
 160         if (fbdev->mem)
 161                 memset(fbdev->mem, 0, fbdev->fb_size * fbdev->buffer_count);
 162 }
 163
 164 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 165 {
 166         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 167         int i;
 168
 169         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 170                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 171
 172         if (y >= 0 && count > 0)
 173                 for (i = 0; i < fbdev->buffer_count; i++)
 174                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 175 }
 176
 177 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 178 {
 179         return fbdev->fd;
 180 }
 181
 182 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 183 {
 184         struct vout_fbdev *fbdev;
 185         int req_w, req_h;
 186         void *pret;
 187         int ret;
 188
 189         fbdev = calloc(1, sizeof(*fbdev));
 190         if (fbdev == NULL)
 191                 return NULL;
 192
 193         fbdev->fd = open(fbdev_name, O_RDWR);
 194         if (fbdev->fd == -1) {
 195                 fprintf(stderr, PFX "%s: ", fbdev_name);
 196                 perror("open");
 197                 goto fail_open;
 198         }
 199
 200         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 201         if (ret == -1) {
 202                 perror(PFX "FBIOGET_VSCREENINFO ioctl");
 203                 goto fail;
 204         }
 205
 206         fbdev->fbvar_new = fbdev->fbvar_old;
 207
 208         req_w = fbdev->fbvar_new.xres;
 209         if (*w != 0)
 210                 req_w = *w;
 211         req_h = fbdev->fbvar_new.yres;
 212         if (*h != 0)
 213                 req_h = *h;
 214
 215         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt, 0);
 216         if (pret == NULL)
 217                 goto fail;
 218
 219         printf(PFX "%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres,
 220                 fbdev->fbvar_new.yres, fbdev->fbvar_new.bits_per_pixel);
 221         *w = fbdev->fbvar_new.xres;
 222         *h = fbdev->fbvar_new.yres;
 223
 224         memset(fbdev->mem, 0, fbdev->mem_size);
 225
 226         // some checks
 227         ret = 0;
 228         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 229         if (ret != 0)
 230                 fprintf(stderr, PFX "Warning: vsync doesn't seem to be supported\n");
 231
 232         if (fbdev->buffer_count > 1) {
 233                 fbdev->buffer_write = 0;
 234                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 235                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 236                 if (ret != 0) {
 237                         fbdev->buffer_count = 1;
 238                         fprintf(stderr, PFX "Warning: can't pan display, doublebuffering disabled\n");
 239                 }
 240         }
 241
 242         printf("fbdev initialized.\n");
 243         return fbdev;
 244
 245 fail:
 246         close(fbdev->fd);
 247 fail_open:
 248         free(fbdev);
 249         return NULL;
 250 }
 251
 252 static void vout_fbdev_release(struct vout_fbdev *fbdev)
 253 {
 254         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 255         if (fbdev->mem != MAP_FAILED)
 256                 munmap(fbdev->mem, fbdev->mem_size);
 257         fbdev->mem = NULL;
 258 }
 259
 260 int vout_fbdev_save(struct vout_fbdev *fbdev)
 261 {
 262         void *tmp;
 263
 264         if (fbdev == NULL || fbdev->mem == NULL || fbdev->mem == MAP_FAILED) {
 265                 fprintf(stderr, PFX "bad args for save\n");
 266                 return -1;
 267         }
 268
 269         if (fbdev->mem_saved_size < fbdev->mem_size) {
 270                 tmp = realloc(fbdev->mem_saved, fbdev->mem_size);
 271                 if (tmp == NULL)
 272                         return -1;
 273                 fbdev->mem_saved = tmp;
 274         }
 275         memcpy(fbdev->mem_saved, fbdev->mem, fbdev->mem_size);
 276         fbdev->mem_saved_size = fbdev->mem_size;
 277
 278         vout_fbdev_release(fbdev);
 279         return 0;
 280 }
 281
 282 int vout_fbdev_restore(struct vout_fbdev *fbdev)
 283 {
 284         int ret;
 285
 286         if (fbdev == NULL || fbdev->mem != NULL) {
 287                 fprintf(stderr, PFX "bad args/state for restore\n");
 288                 return -1;
 289         }
 290
 291         fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 292         if (fbdev->mem == MAP_FAILED) {
 293                 perror(PFX "restore: memory restore failed");
 294                 return -1;
 295         }
 296         memcpy(fbdev->mem, fbdev->mem_saved, fbdev->mem_size);
 297
 298         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 299         if (ret == -1) {
 300                 perror(PFX "restore: FBIOPUT_VSCREENINFO");
 301                 return -1;
 302         }
 303
 304         return 0;
 305 }
 306
 307 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 308 {
 309         vout_fbdev_release(fbdev);
 310         if (fbdev->fd >= 0)
 311                 close(fbdev->fd);
 312         fbdev->fd = -1;
 313         free(fbdev);
 314 }
 315