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 /* it is recommended to call vout_fbdev_clear() before this */
  70 void *vout_fbdev_resize(struct vout_fbdev *fbdev, int w, int h, int bpp,
  71                       int left_border, int right_border, int top_border, int bottom_border, int buffer_cnt)
  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
 104                 // seems to help a bit to avoid glitches
 105                 vout_fbdev_wait_vsync(fbdev);
 106
 107                 ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 108                 if (ret == -1) {
 109                         // retry with no multibuffering
 110                         fbdev->fbvar_new.yres_virtual = h_total;
 111                         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 112                         if (ret == -1) {
 113                                 perror(PFX "FBIOPUT_VSCREENINFO ioctl");
 114                                 return NULL;
 115                         }
 116                         fbdev->buffer_count = 1;
 117                         fbdev->buffer_write = 0;
 118                         fprintf(stderr, PFX "Warning: failed to increase virtual resolution, "
 119                                         "multibuffering disabled\n");
 120                 }
 121
 122         }
 123
 124         fbdev->fb_size = w_total * h_total * bpp / 8;
 125         fbdev->top_border = top_border;
 126         fbdev->bottom_border = bottom_border;
 127
 128         mem_size = fbdev->fb_size * fbdev->buffer_count;
 129         if (fbdev->mem_size >= mem_size)
 130                 goto out;
 131
 132         if (fbdev->mem != NULL)
 133                 munmap(fbdev->mem, fbdev->mem_size);
 134
 135         fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 136         if (fbdev->mem == MAP_FAILED && fbdev->buffer_count > 1) {
 137                 fprintf(stderr, PFX "Warning: can't map %zd bytes, doublebuffering disabled\n", mem_size);
 138                 fbdev->buffer_count = 1;
 139                 fbdev->buffer_write = 0;
 140                 mem_size = fbdev->fb_size;
 141                 fbdev->mem = mmap(0, mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 142         }
 143         if (fbdev->mem == MAP_FAILED) {
 144                 fbdev->mem = NULL;
 145                 fbdev->mem_size = 0;
 146                 perror(PFX "mmap framebuffer");
 147                 return NULL;
 148         }
 149
 150         fbdev->mem_size = mem_size;
 151
 152 out:
 153         return (char *)fbdev->mem + fbdev->fb_size * fbdev->buffer_write;
 154 }
 155
 156 void vout_fbdev_clear(struct vout_fbdev *fbdev)
 157 {
 158         memset(fbdev->mem, 0, fbdev->mem_size);
 159 }
 160
 161 void vout_fbdev_clear_lines(struct vout_fbdev *fbdev, int y, int count)
 162 {
 163         int stride = fbdev->fbvar_new.xres_virtual * fbdev->fbvar_new.bits_per_pixel / 8;
 164         int i;
 165
 166         if (y + count > fbdev->top_border + fbdev->fbvar_new.yres)
 167                 count = fbdev->top_border + fbdev->fbvar_new.yres - y;
 168
 169         if (y >= 0 && count > 0)
 170                 for (i = 0; i < fbdev->buffer_count; i++)
 171                         memset((char *)fbdev->mem + fbdev->fb_size * i + y * stride, 0, stride * count);
 172 }
 173
 174 int vout_fbdev_get_fd(struct vout_fbdev *fbdev)
 175 {
 176         return fbdev->fd;
 177 }
 178
 179 struct vout_fbdev *vout_fbdev_init(const char *fbdev_name, int *w, int *h, int bpp, int buffer_cnt)
 180 {
 181         struct vout_fbdev *fbdev;
 182         int req_w, req_h;
 183         void *pret;
 184         int ret;
 185
 186         fbdev = calloc(1, sizeof(*fbdev));
 187         if (fbdev == NULL)
 188                 return NULL;
 189
 190         fbdev->fd = open(fbdev_name, O_RDWR);
 191         if (fbdev->fd == -1) {
 192                 fprintf(stderr, PFX "%s: ", fbdev_name);
 193                 perror("open");
 194                 goto fail_open;
 195         }
 196
 197         ret = ioctl(fbdev->fd, FBIOGET_VSCREENINFO, &fbdev->fbvar_old);
 198         if (ret == -1) {
 199                 perror(PFX "FBIOGET_VSCREENINFO ioctl");
 200                 goto fail;
 201         }
 202
 203         fbdev->fbvar_new = fbdev->fbvar_old;
 204
 205         req_w = fbdev->fbvar_new.xres;
 206         if (*w != 0)
 207                 req_w = *w;
 208         req_h = fbdev->fbvar_new.yres;
 209         if (*h != 0)
 210                 req_h = *h;
 211
 212         pret = vout_fbdev_resize(fbdev, req_w, req_h, bpp, 0, 0, 0, 0, buffer_cnt);
 213         if (pret == NULL)
 214                 goto fail;
 215
 216         printf(PFX "%s: %ix%i@%d\n", fbdev_name, fbdev->fbvar_new.xres,
 217                 fbdev->fbvar_new.yres, fbdev->fbvar_new.bits_per_pixel);
 218         *w = fbdev->fbvar_new.xres;
 219         *h = fbdev->fbvar_new.yres;
 220
 221         memset(fbdev->mem, 0, fbdev->mem_size);
 222
 223         // some checks
 224         ret = 0;
 225         ret = ioctl(fbdev->fd, FBIO_WAITFORVSYNC, &ret);
 226         if (ret != 0)
 227                 fprintf(stderr, PFX "Warning: vsync doesn't seem to be supported\n");
 228
 229         if (fbdev->buffer_count > 1) {
 230                 fbdev->buffer_write = 0;
 231                 fbdev->fbvar_new.yoffset = fbdev->fbvar_new.yres * (fbdev->buffer_count - 1);
 232                 ret = ioctl(fbdev->fd, FBIOPAN_DISPLAY, &fbdev->fbvar_new);
 233                 if (ret != 0) {
 234                         fbdev->buffer_count = 1;
 235                         fprintf(stderr, PFX "Warning: can't pan display, doublebuffering disabled\n");
 236                 }
 237         }
 238
 239         printf("fbdev initialized.\n");
 240         return fbdev;
 241
 242 fail:
 243         close(fbdev->fd);
 244 fail_open:
 245         free(fbdev);
 246         return NULL;
 247 }
 248
 249 static void vout_fbdev_release(struct vout_fbdev *fbdev)
 250 {
 251         ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_old);
 252         if (fbdev->mem != MAP_FAILED)
 253                 munmap(fbdev->mem, fbdev->mem_size);
 254         fbdev->mem = NULL;
 255 }
 256
 257 int vout_fbdev_save(struct vout_fbdev *fbdev)
 258 {
 259         void *tmp;
 260
 261         if (fbdev == NULL || fbdev->mem == NULL || fbdev->mem == MAP_FAILED) {
 262                 fprintf(stderr, PFX "bad args for save\n");
 263                 return -1;
 264         }
 265
 266         if (fbdev->mem_saved_size < fbdev->mem_size) {
 267                 tmp = realloc(fbdev->mem_saved, fbdev->mem_size);
 268                 if (tmp == NULL)
 269                         return -1;
 270                 fbdev->mem_saved = tmp;
 271         }
 272         memcpy(fbdev->mem_saved, fbdev->mem, fbdev->mem_size);
 273         fbdev->mem_saved_size = fbdev->mem_size;
 274
 275         vout_fbdev_release(fbdev);
 276         return 0;
 277 }
 278
 279 int vout_fbdev_restore(struct vout_fbdev *fbdev)
 280 {
 281         int ret;
 282
 283         if (fbdev == NULL || fbdev->mem != NULL) {
 284                 fprintf(stderr, PFX "bad args/state for restore\n");
 285                 return -1;
 286         }
 287
 288         fbdev->mem = mmap(0, fbdev->mem_size, PROT_WRITE|PROT_READ, MAP_SHARED, fbdev->fd, 0);
 289         if (fbdev->mem == MAP_FAILED) {
 290                 perror(PFX "restore: memory restore failed");
 291                 return -1;
 292         }
 293         memcpy(fbdev->mem, fbdev->mem_saved, fbdev->mem_size);
 294
 295         ret = ioctl(fbdev->fd, FBIOPUT_VSCREENINFO, &fbdev->fbvar_new);
 296         if (ret == -1) {
 297                 perror(PFX "restore: FBIOPUT_VSCREENINFO");
 298                 return -1;
 299         }
 300
 301         return 0;
 302 }
 303
 304 void vout_fbdev_finish(struct vout_fbdev *fbdev)
 305 {
 306         vout_fbdev_release(fbdev);
 307         if (fbdev->fd >= 0)
 308                 close(fbdev->fd);
 309         fbdev->fd = -1;
 310         free(fbdev);
 311 }
 312