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         struct device *tty_dev;
  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         /* make sure suspend/resume doesn't race against port_probe */
  65         retval = usb_autopm_get_interface(port->serial->interface);
  66         if (retval)
  67                 goto exit;
  68
  69         driver = port->serial->type;
  70         if (driver->port_probe) {
  71                 retval = driver->port_probe(port);
  72                 if (retval)
  73                         goto exit_with_autopm;
  74         }
  75
  76         retval = device_create_file(dev, &dev_attr_port_number);
  77         if (retval) {
  78                 if (driver->port_remove)
  79                         driver->port_remove(port);
  80                 goto exit_with_autopm;
  81         }
  82
  83         minor = port->minor;
  84         tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev);
  85         if (IS_ERR(tty_dev)) {
  86                 retval = PTR_ERR(tty_dev);
  87                 device_remove_file(dev, &dev_attr_port_number);
  88                 if (driver->port_remove)
  89                         driver->port_remove(port);
  90                 goto exit_with_autopm;
  91         }
  92
  93         dev_info(&port->serial->dev->dev,
  94                  "%s converter now attached to ttyUSB%d\n",
  95                  driver->description, minor);
  96
  97 exit_with_autopm:
  98         usb_autopm_put_interface(port->serial->interface);
  99 exit:
 100         return retval;
 101 }
 102
 103 static int usb_serial_device_remove(struct device *dev)
 104 {
 105         struct usb_serial_driver *driver;
 106         struct usb_serial_port *port;
 107         int retval = 0;
 108         int minor;
 109         int autopm_err;
 110
 111         port = to_usb_serial_port(dev);
 112         if (!port)
 113                 return -ENODEV;
 114
 115         /*
 116          * Make sure suspend/resume doesn't race against port_remove.
 117          *
 118          * Note that no further runtime PM callbacks will be made if
 119          * autopm_get fails.
 120          */
 121         autopm_err = usb_autopm_get_interface(port->serial->interface);
 122
 123         minor = port->minor;
 124         tty_unregister_device(usb_serial_tty_driver, minor);
 125
 126         device_remove_file(&port->dev, &dev_attr_port_number);
 127
 128         driver = port->serial->type;
 129         if (driver->port_remove)
 130                 retval = driver->port_remove(port);
 131
 132         dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
 133                  driver->description, minor);
 134
 135         if (!autopm_err)
 136                 usb_autopm_put_interface(port->serial->interface);
 137
 138         return retval;
 139 }
 140
 141 static ssize_t new_id_store(struct device_driver *driver,
 142                             const char *buf, size_t count)
 143 {
 144         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 145         ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count);
 146
 147         if (retval >= 0 && usb_drv->usb_driver != NULL)
 148                 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
 149                                           &usb_drv->usb_driver->drvwrap.driver,
 150                                           buf, count);
 151         return retval;
 152 }
 153
 154 static ssize_t new_id_show(struct device_driver *driver, char *buf)
 155 {
 156         struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
 157
 158         return usb_show_dynids(&usb_drv->dynids, buf);
 159 }
 160 static DRIVER_ATTR_RW(new_id);
 161
 162 static struct attribute *usb_serial_drv_attrs[] = {
 163         &driver_attr_new_id.attr,
 164         NULL,
 165 };
 166 ATTRIBUTE_GROUPS(usb_serial_drv);
 167
 168 static void free_dynids(struct usb_serial_driver *drv)
 169 {
 170         struct usb_dynid *dynid, *n;
 171
 172         spin_lock(&drv->dynids.lock);
 173         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 174                 list_del(&dynid->node);
 175                 kfree(dynid);
 176         }
 177         spin_unlock(&drv->dynids.lock);
 178 }
 179
 180 struct bus_type usb_serial_bus_type = {
 181         .name =         "usb-serial",
 182         .match =        usb_serial_device_match,
 183         .probe =        usb_serial_device_probe,
 184         .remove =       usb_serial_device_remove,
 185         .drv_groups =   usb_serial_drv_groups,
 186 };
 187
 188 int usb_serial_bus_register(struct usb_serial_driver *driver)
 189 {
 190         int retval;
 191
 192         driver->driver.bus = &usb_serial_bus_type;
 193         spin_lock_init(&driver->dynids.lock);
 194         INIT_LIST_HEAD(&driver->dynids.list);
 195
 196         retval = driver_register(&driver->driver);
 197
 198         return retval;
 199 }
 200
 201 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
 202 {
 203         free_dynids(driver);
 204         driver_unregister(&driver->driver);
 205 }
 206