linux/linux-5.18.11/drivers/comedi/comedi_usb.c

151 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* comedi_usb.c
* Comedi USB driver specific functions.
*
* COMEDI - Linux Control and Measurement Device Interface
* Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
*/
#include <linux/module.h>
#include <linux/comedi/comedi_usb.h>
/**
* comedi_to_usb_interface() - Return USB interface attached to COMEDI device
* @dev: COMEDI device.
*
* Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
* a &struct device embedded in a &struct usb_interface.
*
* Return: Attached USB interface if @dev->hw_dev is non-%NULL.
* Return %NULL if @dev->hw_dev is %NULL.
*/
struct usb_interface *comedi_to_usb_interface(struct comedi_device *dev)
{
return dev->hw_dev ? to_usb_interface(dev->hw_dev) : NULL;
}
EXPORT_SYMBOL_GPL(comedi_to_usb_interface);
/**
* comedi_to_usb_dev() - Return USB device attached to COMEDI device
* @dev: COMEDI device.
*
* Assuming @dev->hw_dev is non-%NULL, it is assumed to be pointing to a
* a &struct device embedded in a &struct usb_interface.
*
* Return: USB device to which the USB interface belongs if @dev->hw_dev is
* non-%NULL. Return %NULL if @dev->hw_dev is %NULL.
*/
struct usb_device *comedi_to_usb_dev(struct comedi_device *dev)
{
struct usb_interface *intf = comedi_to_usb_interface(dev);
return intf ? interface_to_usbdev(intf) : NULL;
}
EXPORT_SYMBOL_GPL(comedi_to_usb_dev);
/**
* comedi_usb_auto_config() - Configure/probe a USB COMEDI driver
* @intf: USB interface.
* @driver: Registered COMEDI driver.
* @context: Driver specific data, passed to comedi_auto_config().
*
* Typically called from the usb_driver (*probe) function. Auto-configure a
* COMEDI device, using a pointer to the &struct device embedded in *@intf as
* the hardware device. The @context value gets passed through to @driver's
* "auto_attach" handler. The "auto_attach" handler may call
* comedi_to_usb_interface() on the passed in COMEDI device to recover @intf.
*
* Return: The result of calling comedi_auto_config() (%0 on success, or
* a negative error number on failure).
*/
int comedi_usb_auto_config(struct usb_interface *intf,
struct comedi_driver *driver,
unsigned long context)
{
return comedi_auto_config(&intf->dev, driver, context);
}
EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
/**
* comedi_usb_auto_unconfig() - Unconfigure/disconnect a USB COMEDI device
* @intf: USB interface.
*
* Typically called from the usb_driver (*disconnect) function.
* Auto-unconfigure a COMEDI device attached to this USB interface, using a
* pointer to the &struct device embedded in *@intf as the hardware device.
* The COMEDI driver's "detach" handler will be called during unconfiguration
* of the COMEDI device.
*
* Note that the COMEDI device may have already been unconfigured using the
* %COMEDI_DEVCONFIG ioctl, in which case this attempt to unconfigure it
* again should be ignored.
*/
void comedi_usb_auto_unconfig(struct usb_interface *intf)
{
comedi_auto_unconfig(&intf->dev);
}
EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
/**
* comedi_usb_driver_register() - Register a USB COMEDI driver
* @comedi_driver: COMEDI driver to be registered.
* @usb_driver: USB driver to be registered.
*
* This function is called from the module_init() of USB COMEDI driver modules
* to register the COMEDI driver and the USB driver. Do not call it directly,
* use the module_comedi_usb_driver() helper macro instead.
*
* Return: %0 on success, or a negative error number on failure.
*/
int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
struct usb_driver *usb_driver)
{
int ret;
ret = comedi_driver_register(comedi_driver);
if (ret < 0)
return ret;
ret = usb_register(usb_driver);
if (ret < 0) {
comedi_driver_unregister(comedi_driver);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(comedi_usb_driver_register);
/**
* comedi_usb_driver_unregister() - Unregister a USB COMEDI driver
* @comedi_driver: COMEDI driver to be registered.
* @usb_driver: USB driver to be registered.
*
* This function is called from the module_exit() of USB COMEDI driver modules
* to unregister the USB driver and the COMEDI driver. Do not call it
* directly, use the module_comedi_usb_driver() helper macro instead.
*/
void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
struct usb_driver *usb_driver)
{
usb_deregister(usb_driver);
comedi_driver_unregister(comedi_driver);
}
EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
static int __init comedi_usb_init(void)
{
return 0;
}
module_init(comedi_usb_init);
static void __exit comedi_usb_exit(void)
{
}
module_exit(comedi_usb_exit);
MODULE_AUTHOR("https://www.comedi.org");
MODULE_DESCRIPTION("Comedi USB interface module");
MODULE_LICENSE("GPL");