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");