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 port_number_show(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->port_number);
  47 }
  48 static DEVICE_ATTR_RO(port_number);
  49
  50 static int usb_serial_device_probe(struct device *dev)
  51 {
  52         struct usb_serial_driver *driver;
  53         struct usb_serial_port *port;
  54         int retval = 0;
  55         int minor;
  56
  57         port = to_usb_serial_port(dev);
  58         if (!port) {
  59                 retval = -ENODEV;
  60                 goto exit;
  61         }
  62
  63         /* make sure suspend/resume doesn't race against port_probe */
  64         retval = usb_autopm_get_interface(port->serial->interface);
  65         if (retval)
  66                 goto exit;
  67
  68         driver = port->serial->type;
  69         if (driver->port_probe) {
  70                 retval = driver->port_probe(port);
  71                 if (retval)
  72                         goto exit_with_autopm;
  73         }
  74
  75         retval = device_create_file(dev, &dev_attr_port_number);
  76         if (retval) {
  77                 if (driver->port_remove)
  78                         retval = driver->port_remove(port);
  79                 goto exit_with_autopm;
  80         }
  81
  82         minor = port->minor;
  83         tty_register_device(usb_serial_tty_driver, minor, dev);
  84         dev_info(&port->serial->dev->dev,
  85                  "%s converter now attached to ttyUSB%d\n",
  86                  driver->description, minor);
  87
  88 exit_with_autopm:
  89         usb_autopm_put_interface(port->serial->interface);
  90 exit:
  91         return retval;
  92 }
  93
  94 static int usb_serial_device_remove(struct device *dev)
  95 {
  96         struct usb_serial_driver *driver;
  97         struct usb_serial_port *port;
  98         int retval = 0;
  99         int minor;
 100
 101         port = to_usb_serial_port(dev);
 102         if (!port)
 103                 return -ENODEV;
 104
 105         /* make sure suspend/resume doesn't race against port_remove */
 106         usb_autopm_get_interface(port->serial->interface);
 107
 108         minor = port->minor;
 109         tty_unregister_device(usb_serial_tty_driver, minor);
 110
 111         device_remove_file(&port->dev, &dev_attr_port_number);
 112
 113         driver = port->serial->type;
 114         if (driver->port_remove)
 115                 retval = driver->port_remove(port);
 116
 117         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 118                  driver->description, minor);
 119
 120         usb_autopm_put_interface(port->serial->interface);
 121         return retval;
 122 }
 123
 124 static ssize_t new_id_store(struct device_driver *driver,
 125                             const char *buf, size_t count)
 126 {
 127         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 128         ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table,
 129                                          driver, buf, count);
 130
 131         if (retval >= 0 && usb_drv->usb_driver != NULL)
 132                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 133                                           usb_drv->usb_driver->id_table,
 134                                           &usb_drv->usb_driver->drvwrap.driver,
 135                                           buf, count);
 136         return retval;
 137 }
 138
 139 static ssize_t new_id_show(struct device_driver *driver, char *buf)
 140 {
 141         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 142
 143         return usb_show_dynids(&usb_drv->dynids, buf);
 144 }
 145 static DRIVER_ATTR_RW(new_id);
 146
 147 static struct attribute *usb_serial_drv_attrs[] = {
 148         &driver_attr_new_id.attr,
 149         NULL,
 150 };
 151 ATTRIBUTE_GROUPS(usb_serial_drv);
 152
 153 static void free_dynids(struct usb_serial_driver *drv)
 154 {
 155         struct usb_dynid *dynid, *n;
 156
 157         spin_lock(&drv->dynids.lock);
 158         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 159                 list_del(&dynid->node);
 160                 kfree(dynid);
 161         }
 162         spin_unlock(&drv->dynids.lock);
 163 }
 164
 165 struct bus_type usb_serial_bus_type = {
 166         .name =         "usb-serial",
 167         .match =        usb_serial_device_match,
 168         .probe =        usb_serial_device_probe,
 169         .remove =       usb_serial_device_remove,
 170         .drv_groups =   usb_serial_drv_groups,
 171 };
 172
 173 int usb_serial_bus_register(struct usb_serial_driver *driver)
 174 {
 175         int retval;
 176
 177         driver->driver.bus = &usb_serial_bus_type;
 178         spin_lock_init(&driver->dynids.lock);
 179         INIT_LIST_HEAD(&driver->dynids.list);
 180
 181         retval = driver_register(&driver->driver);
 182
 183         return retval;
 184 }
 185
 186 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 187 {
 188         free_dynids(driver);
 189         driver_unregister(&driver->driver);
 190 }
 191