kernel/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 int usb_serial_device_probe(struct device *dev)
  42 {
  43         struct usb_serial_driver *driver;
  44         struct usb_serial_port *port;
  45         struct device *tty_dev;
  46         int retval = 0;
  47         int minor;
  48
  49         port = to_usb_serial_port(dev);
  50         if (!port)
  51                 return -ENODEV;
  52
  53         /* make sure suspend/resume doesn't race against port_probe */
  54         retval = usb_autopm_get_interface(port->serial->interface);
  55         if (retval)
  56                 return retval;
  57
  58         driver = port->serial->type;
  59         if (driver->port_probe) {
  60                 retval = driver->port_probe(port);
  61                 if (retval)
  62                         goto err_autopm_put;
  63         }
  64
  65         minor = port->minor;
  66         tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev);
  67         if (IS_ERR(tty_dev)) {
  68                 retval = PTR_ERR(tty_dev);
  69                 goto err_port_remove;
  70         }
  71
  72         usb_autopm_put_interface(port->serial->interface);
  73
  74         dev_info(&port->serial->dev->dev,
  75                  "%s converter now attached to ttyUSB%d\n",
  76                  driver->description, minor);
  77
  78         return 0;
  79
  80 err_port_remove:
  81         if (driver->port_remove)
  82                 driver->port_remove(port);
  83 err_autopm_put:
  84         usb_autopm_put_interface(port->serial->interface);
  85
  86         return retval;
  87 }
  88
  89 static int usb_serial_device_remove(struct device *dev)
  90 {
  91         struct usb_serial_driver *driver;
  92         struct usb_serial_port *port;
  93         int retval = 0;
  94         int minor;
  95         int autopm_err;
  96
  97         port = to_usb_serial_port(dev);
  98         if (!port)
  99                 return -ENODEV;
 100
 101         /*
 102          * Make sure suspend/resume doesn't race against port_remove.
 103          *
 104          * Note that no further runtime PM callbacks will be made if
 105          * autopm_get fails.
 106          */
 107         autopm_err = usb_autopm_get_interface(port->serial->interface);
 108
 109         minor = port->minor;
 110         tty_unregister_device(usb_serial_tty_driver, minor);
 111
 112         driver = port->serial->type;
 113         if (driver->port_remove)
 114                 retval = driver->port_remove(port);
 115
 116         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 117                  driver->description, minor);
 118
 119         if (!autopm_err)
 120                 usb_autopm_put_interface(port->serial->interface);
 121
 122         return retval;
 123 }
 124
 125 static ssize_t new_id_store(struct device_driver *driver,
 126                             const char *buf, size_t count)
 127 {
 128         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 129         ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table,
 130                                          driver, buf, count);
 131
 132         if (retval >= 0 && usb_drv->usb_driver != NULL)
 133                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 134                                           usb_drv->usb_driver->id_table,
 135                                           &usb_drv->usb_driver->drvwrap.driver,
 136                                           buf, count);
 137         return retval;
 138 }
 139
 140 static ssize_t new_id_show(struct device_driver *driver, char *buf)
 141 {
 142         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 143
 144         return usb_show_dynids(&usb_drv->dynids, buf);
 145 }
 146 static DRIVER_ATTR_RW(new_id);
 147
 148 static struct attribute *usb_serial_drv_attrs[] = {
 149         &driver_attr_new_id.attr,
 150         NULL,
 151 };
 152 ATTRIBUTE_GROUPS(usb_serial_drv);
 153
 154 static void free_dynids(struct usb_serial_driver *drv)
 155 {
 156         struct usb_dynid *dynid, *n;
 157
 158         spin_lock(&drv->dynids.lock);
 159         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 160                 list_del(&dynid->node);
 161                 kfree(dynid);
 162         }
 163         spin_unlock(&drv->dynids.lock);
 164 }
 165
 166 struct bus_type usb_serial_bus_type = {
 167         .name =         "usb-serial",
 168         .match =        usb_serial_device_match,
 169         .probe =        usb_serial_device_probe,
 170         .remove =       usb_serial_device_remove,
 171         .drv_groups =   usb_serial_drv_groups,
 172 };
 173
 174 int usb_serial_bus_register(struct usb_serial_driver *driver)
 175 {
 176         int retval;
 177
 178         driver->driver.bus = &usb_serial_bus_type;
 179         spin_lock_init(&driver->dynids.lock);
 180         INIT_LIST_HEAD(&driver->dynids.list);
 181
 182         retval = driver_register(&driver->driver);
 183
 184         return retval;
 185 }
 186
 187 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 188 {
 189         free_dynids(driver);
 190         driver_unregister(&driver->driver);
 191 }
 192