drivers/usb/serial/bus.c

   1 /*
   2  * USB Serial Converter Bus specific functions
   3  *
   4  * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License version
   8  *      2 as published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/tty.h>
  15 #include <linux/module.h>
  16 #include <linux/usb.h>
  17 #include "usb-serial.h"
  18
  19 static int usb_serial_device_match (struct device *dev, struct device_driver *drv)
  20 {
  21         struct usb_serial_device_type *driver;
  22         const struct usb_serial_port *port;
  23
  24         /*
  25          * drivers are already assigned to ports in serial_probe so it's
  26          * a simple check here.
  27          */
  28         port = to_usb_serial_port(dev);
  29         if (!port)
  30                 return 0;
  31
  32         driver = to_usb_serial_driver(drv);
  33
  34         if (driver == port->serial->type)
  35                 return 1;
  36
  37         return 0;
  38 }
  39
  40 struct bus_type usb_serial_bus_type = {
  41         .name =         "usb-serial",
  42         .match =        usb_serial_device_match,
  43 };
  44
  45 static int usb_serial_device_probe (struct device *dev)
  46 {
  47         struct usb_serial_device_type *driver;
  48         struct usb_serial_port *port;
  49         int retval = 0;
  50         int minor;
  51
  52         port = to_usb_serial_port(dev);
  53         if (!port) {
  54                 retval = -ENODEV;
  55                 goto exit;
  56         }
  57
  58         driver = port->serial->type;
  59         if (driver->port_probe) {
  60                 if (!try_module_get(driver->owner)) {
  61                         dev_err(dev, "module get failed, exiting\n");
  62                         retval = -EIO;
  63                         goto exit;
  64                 }
  65                 retval = driver->port_probe (port);
  66                 module_put(driver->owner);
  67                 if (retval)
  68                         goto exit;
  69         }
  70
  71         minor = port->number;
  72         tty_register_device (usb_serial_tty_driver, minor, dev);
  73         dev_info(&port->serial->dev->dev,
  74                  "%s converter now attached to ttyUSB%d\n",
  75                  driver->name, minor);
  76
  77 exit:
  78         return retval;
  79 }
  80
  81 static int usb_serial_device_remove (struct device *dev)
  82 {
  83         struct usb_serial_device_type *driver;
  84         struct usb_serial_port *port;
  85         int retval = 0;
  86         int minor;
  87
  88         port = to_usb_serial_port(dev);
  89         if (!port) {
  90                 return -ENODEV;
  91         }
  92
  93         driver = port->serial->type;
  94         if (driver->port_remove) {
  95                 if (!try_module_get(driver->owner)) {
  96                         dev_err(dev, "module get failed, exiting\n");
  97                         retval = -EIO;
  98                         goto exit;
  99                 }
 100                 retval = driver->port_remove (port);
 101                 module_put(driver->owner);
 102         }
 103 exit:
 104         minor = port->number;
 105         tty_unregister_device (usb_serial_tty_driver, minor);
 106         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 107                  driver->name, minor);
 108
 109         return retval;
 110 }
 111
 112 int usb_serial_bus_register(struct usb_serial_device_type *device)
 113 {
 114         int retval;
 115
 116         if (device->short_name)
 117                 device->driver.name = (char *)device->short_name;
 118         else
 119                 device->driver.name = (char *)device->name;
 120         device->driver.bus = &usb_serial_bus_type;
 121         device->driver.probe = usb_serial_device_probe;
 122         device->driver.remove = usb_serial_device_remove;
 123
 124         retval = driver_register(&device->driver);
 125
 126         return retval;
 127 }
 128
 129 void usb_serial_bus_deregister(struct usb_serial_device_type *device)
 130 {
 131         driver_unregister (&device->driver);
 132 }
 133