arch/um/drivers/tty.c

   1 /*
   2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <termios.h>
   9 #include "chan_user.h"
  10 #include "kern_constants.h"
  11 #include "os.h"
  12 #include "um_malloc.h"
  13 #include "user.h"
  14
  15 struct tty_chan {
  16         char *dev;
  17         int raw;
  18         struct termios tt;
  19 };
  20
  21 static void *tty_chan_init(char *str, int device, const struct chan_opts *opts)
  22 {
  23         struct tty_chan *data;
  24
  25         if (*str != ':') {
  26                 printk(UM_KERN_ERR "tty_init : channel type 'tty' must specify "
  27                        "a device\n");
  28                 return NULL;
  29         }
  30         str++;
  31
  32         data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
  33         if (data == NULL)
  34                 return NULL;
  35         *data = ((struct tty_chan) { .dev       = str,
  36                                      .raw       = opts->raw });
  37
  38         return data;
  39 }
  40
  41 static int tty_open(int input, int output, int primary, void *d,
  42                     char **dev_out)
  43 {
  44         struct tty_chan *data = d;
  45         int fd, err, mode = 0;
  46
  47         if (input && output)
  48                 mode = O_RDWR;
  49         else if (input)
  50                 mode = O_RDONLY;
  51         else if (output)
  52                 mode = O_WRONLY;
  53
  54         fd = open(data->dev, mode);
  55         if (fd < 0)
  56                 return -errno;
  57
  58         if (data->raw) {
  59                 CATCH_EINTR(err = tcgetattr(fd, &data->tt));
  60                 if (err)
  61                         return err;
  62
  63                 err = raw(fd);
  64                 if (err)
  65                         return err;
  66         }
  67
  68         *dev_out = data->dev;
  69         return fd;
  70 }
  71
  72 const struct chan_ops tty_ops = {
  73         .type           = "tty",
  74         .init           = tty_chan_init,
  75         .open           = tty_open,
  76         .close          = generic_close,
  77         .read           = generic_read,
  78         .write          = generic_write,
  79         .console_write  = generic_console_write,
  80         .window_size    = generic_window_size,
  81         .free           = generic_free,
  82         .winch          = 0,
  83 };