cp/shell/cmd_enable.c

   1 /*
   2  * (C) Copyright 2007-2019  Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * This file is released under the GPLv2.  See the COPYING file for more
   5  * details.
   6  */
   7
   8 /*
   9  *!!! ENABLE
  10  *!! SYNTAX
  11  *! \tok{\sc ENAble}
  12  *! \begin{stack} \tok{ALL} \\ <rdev> \end{stack}
  13  *!! XATNYS
  14  *!! AUTH A
  15  *!! PURPOSE
  16  *! Enables a real device.
  17  */
  18 static int cmd_enable(struct virt_sys *sys, char *cmd, int len)
  19 {
  20         u64 devnum;
  21         struct device *dev;
  22         struct console *con;
  23
  24         SHELL_CMD_AUTH(sys, A);
  25
  26         if (!strcasecmp(cmd, "ALL")) {
  27                 con_printf(sys->con, "ENABLE ALL not yet implemented!\n");
  28                 return 0;
  29         }
  30
  31         cmd = __extract_hex(cmd, &devnum);
  32         if (IS_ERR(cmd))
  33                 return PTR_ERR(cmd);
  34
  35         /* device number must be 16-bit */
  36         if (devnum & ~0xffffUL)
  37                 return -EINVAL;
  38
  39         dev = find_device_by_ccuu(devnum);
  40         if (IS_ERR(dev)) {
  41                 con_printf(sys->con, "Device %04lX not found in configuration\n", devnum);
  42                 return 0;
  43         }
  44
  45         mutex_lock(&dev->lock);
  46
  47         if (dev->in_use) {
  48                 con_printf(sys->con, "Device %04lX is already in use\n", devnum);
  49                 goto out_err;
  50         }
  51
  52         if (!dev->dev->enable) {
  53                 con_printf(sys->con, "Device type %-4s cannot be enabled\n",
  54                            type2name(dev->type));
  55                 goto out_err;
  56         }
  57
  58         con = dev->dev->enable(dev);
  59         if (IS_ERR(con)) {
  60                 con_printf(sys->con, "Failed to enable %04lX: %s\n",
  61                            devnum, errstrings[-PTR_ERR(con)]);
  62                 goto out_err;
  63         }
  64
  65         mutex_unlock(&dev->lock);
  66         return 0;
  67
  68 out_err:
  69         mutex_unlock(&dev->lock);
  70         dev_put(dev);
  71         return 0;
  72 }