LXR linux/drivers/comedi/comedi

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * comedi_usb.c
   4 * Comedi USB driver specific functions.
   5 *
   6 * COMEDI - Linux Control and Measurement Device Interface
   7 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/comedi/comedi_usb.h>
  12
  13/**
  14 * comedi_to_usb_interface() - Return USB interface attached to COMEDI device
  15 * @dev: COMEDI device.
  16 *
  17 * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  18 * a &struct device embedded in a &struct usb_interface.
  19 *
  20 * Return: Attached USB interface if @dev->hw_dev is non-%NULL.
  21 * Return %NULL if @dev->hw_dev is %NULL.
  22 */
  23struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
  24{
  25        return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL;
  26}
  27EXPORT_SYMBOL_GPL(comedi_to_usb_interface);
  28
  29/**
  30 * comedi_to_usb_dev() - Return USB device attached to COMEDI device
  31 * @dev: COMEDI device.
  32 *
  33 * Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
  34 * a &struct device embedded in a &struct usb_interface.
  35 *
  36 * Return: USB device to which the USB interface belongs if @dev->hw_dev is
  37 * non-%NULL.  Return %NULL if @dev->hw_dev is %NULL.
  38 */
  39struct usb_device *comedi_to_usb_dev(struct comedi_device *dev)
  40{
  41        struct usb_interface *intf = comedi_to_usb_interface(dev);
  42
  43        return intf ? interface_to_usbdev(intf) : NULL;
  44}
  45EXPORT_SYMBOL_GPL(comedi_to_usb_dev);
  46
  47/**
  48 * comedi_usb_auto_config() - Configure/probe a USB COMEDI driver
  49 * @intf: USB interface.
  50 * @driver: Registered COMEDI driver.
  51 * @context: Driver specific data, passed to comedi_auto_config().
  52 *
  53 * Typically called from the usb_driver (*probe) function.  Auto-configure a
  54 * COMEDI device, using a pointer to the &struct device embedded in *@intf as
  55 * the hardware device.  The @context value gets passed through to @driver's
  56 * "auto_attach" handler.  The "auto_attach" handler may call
  57 * comedi_to_usb_interface() on the passed in COMEDI device to recover @intf.
  58 *
  59 * Return: The result of calling comedi_auto_config() (%0 on success, or
  60 * a negative error number on failure).
  61 */
  62int comedi_usb_auto_config(struct usb_interface *intf,
  63                           struct comedi_driver *driver,
  64                           unsigned long context)
  65{
  66        return comedi_auto_config(&intf->dev, driver, context);
  67}
  68EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
  69
  70/**
  71 * comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device
  72 * @intf: USB interface.
  73 *
  74 * Typically called from the usb_driver (*disconnect) function.
  75 * Auto-unconfigure a COMEDI device attached to this USB interface, using a
  76 * pointer to the &struct device embedded in *@intf as the hardware device.
  77 * The COMEDI driver's "detach" handler will be called during unconfiguration
  78 * of the COMEDI device.
  79 *
  80 * Note that the COMEDI device may have already been unconfigured using the
  81 * %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
  82 * again should be ignored.
  83 */
  84void comedi_usb_auto_unconfig(struct usb_interface *intf)
  85{
  86        comedi_auto_unconfig(&intf->dev);
  87}
  88EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
  89
  90/**
  91 * comedi_usb_driver_register() - Register a USB COMEDI driver
  92 * @comedi_driver: COMEDI driver to be registered.
  93 * @usb_driver: USB driver to be registered.
  94 *
  95 * This function is called from the module_init() of USB COMEDI driver modules
  96 * to register the COMEDI driver and the USB driver.  Do not call it directly,
  97 * use the module_comedi_usb_driver() helper macro instead.
  98 *
  99 * Return: %0 on success, or a negative error number on failure.
 100 */
 101int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
 102                               struct usb_driver *usb_driver)
 103{
 104        int ret;
 105
 106        ret = comedi_driver_register(comedi_driver);
 107        if (ret < 0)
 108                return ret;
 109
 110        ret = usb_register(usb_driver);
 111        if (ret < 0) {
 112                comedi_driver_unregister(comedi_driver);
 113                return ret;
 114        }
 115
 116        return 0;
 117}
 118EXPORT_SYMBOL_GPL(comedi_usb_driver_register);
 119
 120/**
 121 * comedi_usb_driver_unregister() - Unregister a USB COMEDI driver
 122 * @comedi_driver: COMEDI driver to be registered.
 123 * @usb_driver: USB driver to be registered.
 124 *
 125 * This function is called from the module_exit() of USB COMEDI driver modules
 126 * to unregister the USB driver and the COMEDI driver.  Do not call it
 127 * directly, use the module_comedi_usb_driver() helper macro instead.
 128 */
 129void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
 130                                  struct usb_driver *usb_driver)
 131{
 132        usb_deregister(usb_driver);
 133        comedi_driver_unregister(comedi_driver);
 134}
 135EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
 136
 137static int __init comedi_usb_init(void)
 138{
 139        return 0;
 140}
 141module_init(comedi_usb_init);
 142
 143static void __exit comedi_usb_exit(void)
 144{
 145}
 146module_exit(comedi_usb_exit);
 147
 148MODULE_AUTHOR("https://www.comedi.org");
 149MODULE_DESCRIPTION("Comedi USB interface module");
 150MODULE_LICENSE("GPL");
 151