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/module.h>
  15 #include <linux/usb.h>
  16 #include <linux/usb/serial.h>
  17
  18 static int usb_serial_device_match(struct device *dev,
  19                                                 struct device_driver *drv)
  20 {
  21         struct usb_serial_driver *driver;
  22         const struct usb_serial_port *port;
  23
  24         /*
  25          * drivers are already assigned to ports in serial_probe so it's
  26          * a simple check here.
  27          */
  28         port = to_usb_serial_port(dev);
  29         if (!port)
  30                 return 0;
  31
  32         driver = to_usb_serial_driver(drv);
  33
  34         if (driver == port->serial->type)
  35                 return 1;
  36
  37         return 0;
  38 }
  39
  40 static ssize_t show_port_number(struct device *dev,
  41                                 struct device_attribute *attr, char *buf)
  42 {
  43         struct usb_serial_port *port = to_usb_serial_port(dev);
  44
  45         return sprintf(buf, "%d\n", port->number - port->serial->minor);
  46 }
  47
  48 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
  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         if (port->dev_state != PORT_REGISTERING)
  63                 goto exit;
  64
  65         driver = port->serial->type;
  66         if (driver->port_probe) {
  67                 retval = driver->port_probe(port);
  68                 if (retval)
  69                         goto exit;
  70         }
  71
  72         retval = device_create_file(dev, &dev_attr_port_number);
  73         if (retval) {
  74                 if (driver->port_remove)
  75                         retval = driver->port_remove(port);
  76                 goto exit;
  77         }
  78
  79         minor = port->number;
  80         tty_register_device(usb_serial_tty_driver, minor, dev);
  81         dev_info(&port->serial->dev->dev,
  82                  "%s converter now attached to ttyUSB%d\n",
  83                  driver->description, minor);
  84
  85 exit:
  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
  96         port = to_usb_serial_port(dev);
  97         if (!port)
  98                 return -ENODEV;
  99
 100         if (port->dev_state != PORT_UNREGISTERING)
 101                 return retval;
 102
 103         device_remove_file(&port->dev, &dev_attr_port_number);
 104
 105         driver = port->serial->type;
 106         if (driver->port_remove)
 107                 retval = driver->port_remove(port);
 108
 109         minor = port->number;
 110         tty_unregister_device(usb_serial_tty_driver, minor);
 111         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 112                  driver->description, minor);
 113
 114         return retval;
 115 }
 116
 117 #ifdef CONFIG_HOTPLUG
 118 static ssize_t store_new_id(struct device_driver *driver,
 119                             const char *buf, size_t count)
 120 {
 121         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 122         ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count);
 123
 124         if (retval >= 0 && usb_drv->usb_driver != NULL)
 125                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 126                                           &usb_drv->usb_driver->drvwrap.driver,
 127                                           buf, count);
 128         return retval;
 129 }
 130
 131 static struct driver_attribute drv_attrs[] = {
 132         __ATTR(new_id, S_IWUSR, NULL, store_new_id),
 133         __ATTR_NULL,
 134 };
 135
 136 static void free_dynids(struct usb_serial_driver *drv)
 137 {
 138         struct usb_dynid *dynid, *n;
 139
 140         spin_lock(&drv->dynids.lock);
 141         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 142                 list_del(&dynid->node);
 143                 kfree(dynid);
 144         }
 145         spin_unlock(&drv->dynids.lock);
 146 }
 147
 148 #else
 149 static struct driver_attribute drv_attrs[] = {
 150         __ATTR_NULL,
 151 };
 152 static inline void free_dynids(struct usb_serial_driver *drv)
 153 {
 154 }
 155 #endif
 156
 157 struct bus_type usb_serial_bus_type = {
 158         .name =         "usb-serial",
 159         .match =        usb_serial_device_match,
 160         .probe =        usb_serial_device_probe,
 161         .remove =       usb_serial_device_remove,
 162         .drv_attrs =    drv_attrs,
 163 };
 164
 165 int usb_serial_bus_register(struct usb_serial_driver *driver)
 166 {
 167         int retval;
 168
 169         driver->driver.bus = &usb_serial_bus_type;
 170         spin_lock_init(&driver->dynids.lock);
 171         INIT_LIST_HEAD(&driver->dynids.list);
 172
 173         retval = driver_register(&driver->driver);
 174
 175         return retval;
 176 }
 177
 178 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 179 {
 180         free_dynids(driver);
 181         driver_unregister(&driver->driver);
 182 }
 183