arch/um/drivers/null.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdlib.h>
   7 #include <errno.h>
   8 #include "chan_user.h"
   9 #include "os.h"
  10
  11 static int null_chan;
  12
  13 void *null_init(char *str, int device, struct chan_opts *opts)
  14 {
  15         return(&null_chan);
  16 }
  17
  18 int null_open(int input, int output, int primary, void *d, char **dev_out)
  19 {
  20         *dev_out = NULL;
  21         return(os_open_file(DEV_NULL, of_rdwr(OPENFLAGS()), 0));
  22 }
  23
  24 int null_read(int fd, char *c_out, void *unused)
  25 {
  26         return(-ENODEV);
  27 }
  28
  29 void null_free(void *data)
  30 {
  31 }
  32
  33 struct chan_ops null_ops = {
  34         .type           = "null",
  35         .init           = null_init,
  36         .open           = null_open,
  37         .close          = generic_close,
  38         .read           = null_read,
  39         .write          = generic_write,
  40         .console_write  = generic_console_write,
  41         .window_size    = generic_window_size,
  42         .free           = null_free,
  43         .winch          = 0,
  44 };
  45
  46 /*
  47  * Overrides for Emacs so that we follow Linus's tabbing style.
  48  * Emacs will notice this stuff at the end of the file and automatically
  49  * adjust the settings for this buffer only.  This must remain at the end
  50  * of the file.
  51  * ---------------------------------------------------------------------------
  52  * Local variables:
  53  * c-file-style: "linux"
  54  * End:
  55  */