xref: /kernel/linux/linux-6.6/drivers/comedi/comedi_pci.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * comedi_pci.c
 * Comedi PCI 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/interrupt.h>
#include <linux/comedi/comedi_pci.h>

/**
 * comedi_to_pci_dev() - Return PCI 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 pci_dev.
 *
 * Return: Attached PCI device if @dev->hw_dev is non-%NULL.
 * Return %NULL if @dev->hw_dev is %NULL.
 */
struct pci_dev *comedi_to_pci_dev(struct comedi_device *dev)
{
	return dev->hw_dev ? to_pci_dev(dev->hw_dev) : NULL;
}
EXPORT_SYMBOL_GPL(comedi_to_pci_dev);

/**
 * comedi_pci_enable() - Enable the PCI device and request the regions
 * @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 pci_dev.  Enable the PCI device
 * and request its regions.  Set @dev->ioenabled to %true if successful,
 * otherwise undo what was done.
 *
 * Calls to comedi_pci_enable() and comedi_pci_disable() cannot be nested.
 *
 * Return:
 *	0 on success,
 *	-%ENODEV if @dev->hw_dev is %NULL,
 *	-%EBUSY if regions busy,
 *	or some negative error number if failed to enable PCI device.
 *
 */
int comedi_pci_enable(struct comedi_device *dev)
{
	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
	int rc;

	if (!pcidev)
		return -ENODEV;

	rc = pci_enable_device(pcidev);
	if (rc < 0)
		return rc;

	rc = pci_request_regions(pcidev, dev->board_name);
	if (rc < 0)
		pci_disable_device(pcidev);
	else
		dev->ioenabled = true;

	return rc;
}
EXPORT_SYMBOL_GPL(comedi_pci_enable);

/**
 * comedi_pci_disable() - Release the regions and disable the PCI 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 pci_dev.  If the earlier call
 * to comedi_pci_enable() was successful, release the PCI device's regions
 * and disable it.  Reset @dev->ioenabled back to %false.
 */
void comedi_pci_disable(struct comedi_device *dev)
{
	struct pci_dev *pcidev = comedi_to_pci_dev(dev);

	if (pcidev && dev->ioenabled) {
		pci_release_regions(pcidev);
		pci_disable_device(pcidev);
	}
	dev->ioenabled = false;
}
EXPORT_SYMBOL_GPL(comedi_pci_disable);

/**
 * comedi_pci_detach() - A generic "detach" handler for PCI COMEDI drivers
 * @dev: COMEDI device.
 *
 * COMEDI drivers for PCI devices that need no special clean-up of private data
 * and have no ioremapped regions other than that pointed to by @dev->mmio may
 * use this function as its "detach" handler called by the COMEDI core when a
 * COMEDI device is being detached from the low-level driver.  It may be also
 * called from a more specific "detach" handler that does additional clean-up.
 *
 * Free the IRQ if @dev->irq is non-zero, iounmap @dev->mmio if it is
 * non-%NULL, and call comedi_pci_disable() to release the PCI device's regions
 * and disable it.
 */
void comedi_pci_detach(struct comedi_device *dev)
{
	struct pci_dev *pcidev = comedi_to_pci_dev(dev);

	if (!pcidev || !dev->ioenabled)
		return;

	if (dev->irq) {
		free_irq(dev->irq, dev);
		dev->irq = 0;
	}
	if (dev->mmio) {
		iounmap(dev->mmio);
		dev->mmio = NULL;
	}
	comedi_pci_disable(dev);
}
EXPORT_SYMBOL_GPL(comedi_pci_detach);

/**
 * comedi_pci_auto_config() - Configure/probe a PCI COMEDI device
 * @pcidev: PCI device.
 * @driver: Registered COMEDI driver.
 * @context: Driver specific data, passed to comedi_auto_config().
 *
 * Typically called from the pci_driver (*probe) function.  Auto-configure
 * a COMEDI device, using the &struct device embedded in *@pcidev as the
 * hardware device.  The @context value gets passed through to @driver's
 * "auto_attach" handler.  The "auto_attach" handler may call
 * comedi_to_pci_dev() on the passed in COMEDI device to recover @pcidev.
 *
 * Return: The result of calling comedi_auto_config() (0 on success, or
 * a negative error number on failure).
 */
int comedi_pci_auto_config(struct pci_dev *pcidev,
			   struct comedi_driver *driver,
			   unsigned long context)
{
	return comedi_auto_config(&pcidev->dev, driver, context);
}
EXPORT_SYMBOL_GPL(comedi_pci_auto_config);

/**
 * comedi_pci_auto_unconfig() - Unconfigure/remove a PCI COMEDI device
 * @pcidev: PCI device.
 *
 * Typically called from the pci_driver (*remove) function.  Auto-unconfigure
 * a COMEDI device attached to this PCI device, using a pointer to the
 * &struct device embedded in *@pcidev 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_pci_auto_unconfig(struct pci_dev *pcidev)
{
	comedi_auto_unconfig(&pcidev->dev);
}
EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig);

/**
 * comedi_pci_driver_register() - Register a PCI COMEDI driver
 * @comedi_driver: COMEDI driver to be registered.
 * @pci_driver: PCI driver to be registered.
 *
 * This function is called from the module_init() of PCI COMEDI driver modules
 * to register the COMEDI driver and the PCI driver.  Do not call it directly,
 * use the module_comedi_pci_driver() helper macro instead.
 *
 * Return: 0 on success, or a negative error number on failure.
 */
int comedi_pci_driver_register(struct comedi_driver *comedi_driver,
			       struct pci_driver *pci_driver)
{
	int ret;

	ret = comedi_driver_register(comedi_driver);
	if (ret < 0)
		return ret;

	ret = pci_register_driver(pci_driver);
	if (ret < 0) {
		comedi_driver_unregister(comedi_driver);
		return ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(comedi_pci_driver_register);

/**
 * comedi_pci_driver_unregister() - Unregister a PCI COMEDI driver
 * @comedi_driver: COMEDI driver to be unregistered.
 * @pci_driver: PCI driver to be unregistered.
 *
 * This function is called from the module_exit() of PCI COMEDI driver modules
 * to unregister the PCI driver and the COMEDI driver.  Do not call it
 * directly, use the module_comedi_pci_driver() helper macro instead.
 */
void comedi_pci_driver_unregister(struct comedi_driver *comedi_driver,
				  struct pci_driver *pci_driver)
{
	pci_unregister_driver(pci_driver);
	comedi_driver_unregister(comedi_driver);
}
EXPORT_SYMBOL_GPL(comedi_pci_driver_unregister);

static int __init comedi_pci_init(void)
{
	return 0;
}
module_init(comedi_pci_init);

static void __exit comedi_pci_exit(void)
{
}
module_exit(comedi_pci_exit);

MODULE_AUTHOR("https://www.comedi.org");
MODULE_DESCRIPTION("Comedi PCI interface module");
MODULE_LICENSE("GPL");