drivers/staging/comedi/comedi_usb.c

   1 /*
   2  * comedi_usb.c
   3  * Comedi USB driver specific functions.
   4  *
   5  * COMEDI - Linux Control and Measurement Device Interface
   6  * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/module.h>
  20
  21 #include "comedi_usb.h"
  22
  23 /**
  24  * comedi_to_usb_interface() - Return USB interface attached to COMEDI device
  25  * @dev: COMEDI device.
  26  *
  27  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  28  * a &struct device embedded in a &struct usb_interface.
  29  *
  30  * Return: Attached USB interface if @dev->hw_dev is non-%NULL.
  31  * Return %NULL if @dev->hw_dev is %NULL.
  32  */
  33 struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
  34 {
  35         return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL;
  36 }
  37 EXPORT_SYMBOL_GPL(comedi_to_usb_interface);
  38
  39 /**
  40  * comedi_to_usb_dev() - Return USB device attached to COMEDI device
  41  * @dev: COMEDI device.
  42  *
  43  * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  44  * a &struct device embedded in a &struct usb_interface.
  45  *
  46  * Return: USB device to which the USB interface belongs if @dev->hw_dev is
  47  * non-%NULL.  Return %NULL if @dev->hw_dev is %NULL.
  48  */
  49 struct usb_device *comedi_to_usb_dev(struct comedi_device *dev)
  50 {
  51         struct usb_interface *intf = comedi_to_usb_interface(dev);
  52
  53         return intf ? interface_to_usbdev(intf) : NULL;
  54 }
  55 EXPORT_SYMBOL_GPL(comedi_to_usb_dev);
  56
  57 /**
  58  * comedi_usb_auto_config() - Configure/probe a USB COMEDI driver
  59  * @intf: USB interface.
  60  * @driver: Registered COMEDI driver.
  61  * @context: Driver specific data, passed to comedi_auto_config().
  62  *
  63  * Typically called from the usb_driver (*probe) function.  Auto-configure a
  64  * COMEDI device, using a pointer to the &struct device embedded in *@intf as
  65  * the hardware device.  The @context value gets passed through to @driver's
  66  * "auto_attach" handler.  The "auto_attach" handler may call
  67  * comedi_to_usb_interface() on the passed in COMEDI device to recover @intf.
  68  *
  69  * Return: The result of calling comedi_auto_config() (%0 on success, or
  70  * a negative error number on failure).
  71  */
  72 int comedi_usb_auto_config(struct usb_interface *intf,
  73                            struct comedi_driver *driver,
  74                            unsigned long context)
  75 {
  76         return comedi_auto_config(&intf->dev, driver, context);
  77 }
  78 EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
  79
  80 /**
  81  * comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device
  82  * @intf: USB interface.
  83  *
  84  * Typically called from the usb_driver (*disconnect) function.
  85  * Auto-unconfigure a COMEDI device attached to this USB interface, using a
  86  * pointer to the &struct device embedded in *@intf as the hardware device.
  87  * The COMEDI driver's "detach" handler will be called during unconfiguration
  88  * of the COMEDI device.
  89  *
  90  * Note that the COMEDI device may have already been unconfigured using the
  91  * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
  92  * again should be ignored.
  93  */
  94 void comedi_usb_auto_unconfig(struct usb_interface *intf)
  95 {
  96         comedi_auto_unconfig(&intf->dev);
  97 }
  98 EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
  99
 100 /**
 101  * comedi_usb_driver_register() - Register a USB COMEDI driver
 102  * @comedi_driver: COMEDI driver to be registered.
 103  * @usb_driver: USB driver to be registered.
 104  *
 105  * This function is called from the module_init() of USB COMEDI driver modules
 106  * to register the COMEDI driver and the USB driver.  Do not call it directly,
 107  * use the module_comedi_usb_driver() helper macro instead.
 108  *
 109  * Return: %0 on success, or a negative error number on failure.
 110  */
 111 int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
 112                                struct usb_driver *usb_driver)
 113 {
 114         int ret;
 115
 116         ret = comedi_driver_register(comedi_driver);
 117         if (ret < 0)
 118                 return ret;
 119
 120         ret = usb_register(usb_driver);
 121         if (ret < 0) {
 122                 comedi_driver_unregister(comedi_driver);
 123                 return ret;
 124         }
 125
 126         return 0;
 127 }
 128 EXPORT_SYMBOL_GPL(comedi_usb_driver_register);
 129
 130 /**
 131  * comedi_usb_driver_unregister() - Unregister a USB COMEDI driver
 132  * @comedi_driver: COMEDI driver to be registered.
 133  * @usb_driver: USB driver to be registered.
 134  *
 135  * This function is called from the module_exit() of USB COMEDI driver modules
 136  * to unregister the USB driver and the COMEDI driver.  Do not call it
 137  * directly, use the module_comedi_usb_driver() helper macro instead.
 138  */
 139 void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
 140                                   struct usb_driver *usb_driver)
 141 {
 142         usb_deregister(usb_driver);
 143         comedi_driver_unregister(comedi_driver);
 144 }
 145 EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
 146
 147 static int __init comedi_usb_init(void)
 148 {
 149         return 0;
 150 }
 151 module_init(comedi_usb_init);
 152
 153 static void __exit comedi_usb_exit(void)
 154 {
 155 }
 156 module_exit(comedi_usb_exit);
 157
 158 MODULE_AUTHOR("http://www.comedi.org");
 159 MODULE_DESCRIPTION("Comedi USB interface module");
 160 MODULE_LICENSE("GPL");