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         int autopm_err;
 101
 102         port = to_usb_serial_port(dev);
 103         if (!port)
 104                 return -ENODEV;
 105
 106         /*
 107          * Make sure suspend/resume doesn't race against port_remove.
 108          *
 109          * Note that no further runtime PM callbacks will be made if
 110          * autopm_get fails.
 111          */
 112         autopm_err = usb_autopm_get_interface(port->serial->interface);
 113
 114         minor = port->minor;
 115         tty_unregister_device(usb_serial_tty_driver, minor);
 116
 117         device_remove_file(&port->dev, &dev_attr_port_number);
 118
 119         driver = port->serial->type;
 120         if (driver->port_remove)
 121                 retval = driver->port_remove(port);
 122
 123         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 124                  driver->description, minor);
 125
 126         if (!autopm_err)
 127                 usb_autopm_put_interface(port->serial->interface);
 128
 129         return retval;
 130 }
 131
 132 static ssize_t new_id_store(struct device_driver *driver,
 133                             const char *buf, size_t count)
 134 {
 135         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 136         ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table,
 137                                          driver, buf, count);
 138
 139         if (retval >= 0 && usb_drv->usb_driver != NULL)
 140                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 141                                           usb_drv->usb_driver->id_table,
 142                                           &usb_drv->usb_driver->drvwrap.driver,
 143                                           buf, count);
 144         return retval;
 145 }
 146
 147 static ssize_t new_id_show(struct device_driver *driver, char *buf)
 148 {
 149         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 150
 151         return usb_show_dynids(&usb_drv->dynids, buf);
 152 }
 153 static DRIVER_ATTR_RW(new_id);
 154
 155 static struct attribute *usb_serial_drv_attrs[] = {
 156         &driver_attr_new_id.attr,
 157         NULL,
 158 };
 159 ATTRIBUTE_GROUPS(usb_serial_drv);
 160
 161 static void free_dynids(struct usb_serial_driver *drv)
 162 {
 163         struct usb_dynid *dynid, *n;
 164
 165         spin_lock(&drv->dynids.lock);
 166         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 167                 list_del(&dynid->node);
 168                 kfree(dynid);
 169         }
 170         spin_unlock(&drv->dynids.lock);
 171 }
 172
 173 struct bus_type usb_serial_bus_type = {
 174         .name =         "usb-serial",
 175         .match =        usb_serial_device_match,
 176         .probe =        usb_serial_device_probe,
 177         .remove =       usb_serial_device_remove,
 178         .drv_groups =   usb_serial_drv_groups,
 179 };
 180
 181 int usb_serial_bus_register(struct usb_serial_driver *driver)
 182 {
 183         int retval;
 184
 185         driver->driver.bus = &usb_serial_bus_type;
 186         spin_lock_init(&driver->dynids.lock);
 187         INIT_LIST_HEAD(&driver->dynids.list);
 188
 189         retval = driver_register(&driver->driver);
 190
 191         return retval;
 192 }
 193
 194 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 195 {
 196         free_dynids(driver);
 197         driver_unregister(&driver->driver);
 198 }
 199