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
  18 #ifdef CONFIG_USB_SERIAL_DEBUG
  19         static int debug = 1;
  20 #else
  21         static int debug;
  22 #endif
  23
  24 #include "usb-serial.h"
  25
  26 static int usb_serial_device_match (struct device *dev, struct device_driver *drv)
  27 {
  28         struct usb_serial_device_type *driver;
  29         const struct usb_serial_port *port;
  30
  31         /*
  32          * drivers are already assigned to ports in serial_probe so it's
  33          * a simple check here.
  34          */
  35         port = to_usb_serial_port(dev);
  36         if (!port)
  37                 return 0;
  38
  39         driver = to_usb_serial_driver(drv);
  40
  41         if (driver == port->serial->type)
  42                 return 1;
  43
  44         return 0;
  45 }
  46
  47 struct bus_type usb_serial_bus_type = {
  48         .name =         "usb-serial",
  49         .match =        usb_serial_device_match,
  50 };
  51
  52 static int usb_serial_device_probe (struct device *dev)
  53 {
  54         struct usb_serial_device_type *driver;
  55         struct usb_serial_port *port;
  56         int retval = 0;
  57         int minor;
  58
  59         port = to_usb_serial_port(dev);
  60         if (!port) {
  61                 retval = -ENODEV;
  62                 goto exit;
  63         }
  64
  65         driver = port->serial->type;
  66         if (driver->port_probe) {
  67                 if (!try_module_get(driver->owner)) {
  68                         dev_err(dev, "module get failed, exiting\n");
  69                         retval = -EIO;
  70                         goto exit;
  71                 }
  72                 retval = driver->port_probe (port);
  73                 module_put(driver->owner);
  74                 if (retval)
  75                         goto exit;
  76         }
  77
  78         minor = port->number;
  79         tty_register_device (usb_serial_tty_driver, minor, dev);
  80         dev_info(&port->serial->dev->dev,
  81                  "%s converter now attached to ttyUSB%d (or usb/tts/%d for devfs)\n",
  82                  driver->name, minor, minor);
  83
  84 exit:
  85         return retval;
  86 }
  87
  88 static int usb_serial_device_remove (struct device *dev)
  89 {
  90         struct usb_serial_device_type *driver;
  91         struct usb_serial_port *port;
  92         int retval = 0;
  93         int minor;
  94
  95         port = to_usb_serial_port(dev);
  96         if (!port) {
  97                 return -ENODEV;
  98         }
  99
 100         driver = port->serial->type;
 101         if (driver->port_remove) {
 102                 if (!try_module_get(driver->owner)) {
 103                         dev_err(dev, "module get failed, exiting\n");
 104                         retval = -EIO;
 105                         goto exit;
 106                 }
 107                 retval = driver->port_remove (port);
 108                 module_put(driver->owner);
 109         }
 110 exit:
 111         minor = port->number;
 112         tty_unregister_device (usb_serial_tty_driver, minor);
 113         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 114                  driver->name, minor);
 115
 116         return retval;
 117 }
 118
 119 int usb_serial_bus_register(struct usb_serial_device_type *device)
 120 {
 121         int retval;
 122
 123         if (device->short_name)
 124                 device->driver.name = (char *)device->short_name;
 125         else
 126                 device->driver.name = (char *)device->name;
 127         device->driver.bus = &usb_serial_bus_type;
 128         device->driver.probe = usb_serial_device_probe;
 129         device->driver.remove = usb_serial_device_remove;
 130
 131         retval = driver_register(&device->driver);
 132
 133         return retval;
 134 }
 135
 136 void usb_serial_bus_deregister(struct usb_serial_device_type *device)
 137 {
 138         driver_unregister (&device->driver);
 139 }
 140