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/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/tty.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/usb.h>
  17 #include <linux/usb/serial.h>
  18
  19 static int usb_serial_device_match(struct device *dev,
  20                                                 struct device_driver *drv)
  21 {
  22         struct usb_serial_driver *driver;
  23         const struct usb_serial_port *port;
  24
  25         /*
  26          * drivers are already assigned to ports in serial_probe so it's
  27          * a simple check here.
  28          */
  29         port = to_usb_serial_port(dev);
  30         if (!port)
  31                 return 0;
  32
  33         driver = to_usb_serial_driver(drv);
  34
  35         if (driver == port->serial->type)
  36                 return 1;
  37
  38         return 0;
  39 }
  40
  41 static ssize_t show_port_number(struct device *dev,
  42                                 struct device_attribute *attr, char *buf)
  43 {
  44         struct usb_serial_port *port = to_usb_serial_port(dev);
  45
  46         return sprintf(buf, "%d\n", port->number - port->serial->minor);
  47 }
  48
  49 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
  50
  51 static int usb_serial_device_probe(struct device *dev)
  52 {
  53         struct usb_serial_driver *driver;
  54         struct usb_serial_port *port;
  55         int retval = 0;
  56         int minor;
  57
  58         port = to_usb_serial_port(dev);
  59         if (!port) {
  60                 retval = -ENODEV;
  61                 goto exit;
  62         }
  63
  64         driver = port->serial->type;
  65         if (driver->port_probe) {
  66                 retval = driver->port_probe(port);
  67                 if (retval)
  68                         goto exit;
  69         }
  70
  71         retval = device_create_file(dev, &dev_attr_port_number);
  72         if (retval) {
  73                 if (driver->port_remove)
  74                         retval = driver->port_remove(port);
  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\n",
  82                  driver->description, minor);
  83
  84 exit:
  85         return retval;
  86 }
  87
  88 static int usb_serial_device_remove(struct device *dev)
  89 {
  90         struct usb_serial_driver *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         device_remove_file(&port->dev, &dev_attr_port_number);
 100
 101         driver = port->serial->type;
 102         if (driver->port_remove)
 103                 retval = driver->port_remove(port);
 104
 105         minor = port->number;
 106         tty_unregister_device(usb_serial_tty_driver, minor);
 107         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 108                  driver->description, minor);
 109
 110         return retval;
 111 }
 112
 113 #ifdef CONFIG_HOTPLUG
 114 static ssize_t store_new_id(struct device_driver *driver,
 115                             const char *buf, size_t count)
 116 {
 117         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 118         ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count);
 119
 120         if (retval >= 0 && usb_drv->usb_driver != NULL)
 121                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 122                                           &usb_drv->usb_driver->drvwrap.driver,
 123                                           buf, count);
 124         return retval;
 125 }
 126
 127 static struct driver_attribute drv_attrs[] = {
 128         __ATTR(new_id, S_IWUSR, NULL, store_new_id),
 129         __ATTR_NULL,
 130 };
 131
 132 static void free_dynids(struct usb_serial_driver *drv)
 133 {
 134         struct usb_dynid *dynid, *n;
 135
 136         spin_lock(&drv->dynids.lock);
 137         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 138                 list_del(&dynid->node);
 139                 kfree(dynid);
 140         }
 141         spin_unlock(&drv->dynids.lock);
 142 }
 143
 144 #else
 145 static struct driver_attribute drv_attrs[] = {
 146         __ATTR_NULL,
 147 };
 148 static inline void free_dynids(struct usb_serial_driver *drv)
 149 {
 150 }
 151 #endif
 152
 153 struct bus_type usb_serial_bus_type = {
 154         .name =         "usb-serial",
 155         .match =        usb_serial_device_match,
 156         .probe =        usb_serial_device_probe,
 157         .remove =       usb_serial_device_remove,
 158         .drv_attrs =    drv_attrs,
 159 };
 160
 161 int usb_serial_bus_register(struct usb_serial_driver *driver)
 162 {
 163         int retval;
 164
 165         driver->driver.bus = &usb_serial_bus_type;
 166         spin_lock_init(&driver->dynids.lock);
 167         INIT_LIST_HEAD(&driver->dynids.list);
 168
 169         retval = driver_register(&driver->driver);
 170
 171         return retval;
 172 }
 173
 174 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 175 {
 176         free_dynids(driver);
 177         driver_unregister(&driver->driver);
 178 }
 179