drivers/comedi/comedi_usb.c

   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  */
  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  */
  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  */
  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  */
  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  */
 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  */
 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
 137 static int __init comedi_usb_init(void)
 138 {
 139         return 0;
 140 }
 141 module_init(comedi_usb_init);
 142
 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");