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