xref: /openbmc/linux/drivers/comedi/comedi_usb.c (revision df0e68c1)
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  */
comedi_to_usb_interface(struct comedi_device * dev)23 struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
24 {
25 	return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL;
26 }
27 EXPORT_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  */
comedi_to_usb_dev(struct comedi_device * dev)39 struct 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 }
45 EXPORT_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  */
comedi_usb_auto_config(struct usb_interface * intf,struct comedi_driver * driver,unsigned long context)62 int 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 }
68 EXPORT_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  */
comedi_usb_auto_unconfig(struct usb_interface * intf)84 void comedi_usb_auto_unconfig(struct usb_interface *intf)
85 {
86 	comedi_auto_unconfig(&intf->dev);
87 }
88 EXPORT_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  */
comedi_usb_driver_register(struct comedi_driver * comedi_driver,struct usb_driver * usb_driver)101 int 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 }
118 EXPORT_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  */
comedi_usb_driver_unregister(struct comedi_driver * comedi_driver,struct usb_driver * usb_driver)129 void 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 }
135 EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
136 
comedi_usb_init(void)137 static int __init comedi_usb_init(void)
138 {
139 	return 0;
140 }
141 module_init(comedi_usb_init);
142 
comedi_usb_exit(void)143 static void __exit comedi_usb_exit(void)
144 {
145 }
146 module_exit(comedi_usb_exit);
147 
148 MODULE_AUTHOR("https://www.comedi.org");
149 MODULE_DESCRIPTION("Comedi USB interface module");
150 MODULE_LICENSE("GPL");
151