drivers/pci/pci-driver.c - kernel/msm-4.9 - Gitiles

 /*
  * drivers/pci/pci-driver.c
  *
  */

 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/pci-dynids.h>
 #include "pci.h"

 /*
  *  Registration of PCI drivers and handling of hot-pluggable devices.
  */

 /*
  * Dynamic device IDs are disabled for !CONFIG_HOTPLUG
  */

 #ifdef CONFIG_HOTPLUG
 /**
  * pci_device_probe_dynamic()
  *
  * Walk the dynamic ID list looking for a match.
  * returns 0 and sets pci_dev->driver when drv claims pci_dev, else error.
  */
 static int
 pci_device_probe_dynamic(struct pci_driver *drv, struct pci_dev *pci_dev)
 {
 	int error = -ENODEV;
 	struct list_head *pos;
 	struct dynid *dynid;

 	spin_lock(&drv->dynids.lock);
 	list_for_each(pos, &drv->dynids.list) {
 		dynid = list_entry(pos, struct dynid, node);
 		if (pci_match_one_device(&dynid->id, pci_dev)) {
 			spin_unlock(&drv->dynids.lock);
 			error = drv->probe(pci_dev, &dynid->id);
 			if (error >= 0) {
 				pci_dev->driver = drv;
 				return 0;
 			}
 			return error;
 		}
 	}
 	spin_unlock(&drv->dynids.lock);
 	return error;
 }

 /**
  * store_new_id
  *
  * Adds a new dynamic pci device ID to this driver,
  * and causes the driver to probe for all devices again.
  */
 static inline ssize_t
 store_new_id(struct device_driver *driver, const char *buf, size_t count)
 {
 	struct dynid *dynid;
 	struct bus_type * bus;
 	struct pci_driver *pdrv = to_pci_driver(driver);
 	__u32 vendor=PCI_ANY_ID, device=PCI_ANY_ID, subvendor=PCI_ANY_ID,
 		subdevice=PCI_ANY_ID, class=0, class_mask=0;
 	unsigned long driver_data=0;
 	int fields=0;

 	fields = sscanf(buf, "%x %x %x %x %x %x %lux",
 			&vendor, &device, &subvendor, &subdevice,
 			&class, &class_mask, &driver_data);
 	if (fields < 0)
 		return -EINVAL;

 	dynid = kmalloc(sizeof(*dynid), GFP_KERNEL);
 	if (!dynid)
 		return -ENOMEM;

 	memset(dynid, 0, sizeof(*dynid));
 	INIT_LIST_HEAD(&dynid->node);
 	dynid->id.vendor = vendor;
 	dynid->id.device = device;
 	dynid->id.subvendor = subvendor;
 	dynid->id.subdevice = subdevice;
 	dynid->id.class = class;
 	dynid->id.class_mask = class_mask;
 	dynid->id.driver_data = pdrv->dynids.use_driver_data ?
 		driver_data : 0UL;

 	spin_lock(&pdrv->dynids.lock);
 	list_add_tail(&pdrv->dynids.list, &dynid->node);
 	spin_unlock(&pdrv->dynids.lock);

 	bus = get_bus(pdrv->driver.bus);
 	if (bus) {
 		if (get_driver(&pdrv->driver)) {
 			down_write(&bus->subsys.rwsem);
 			driver_attach(&pdrv->driver);
 			up_write(&bus->subsys.rwsem);
 			put_driver(&pdrv->driver);
 		}
 		put_bus(bus);
 	}

 	return count;
 }

 static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
 static inline void
 pci_init_dynids(struct pci_dynids *dynids)
 {
 	spin_lock_init(&dynids->lock);
 	INIT_LIST_HEAD(&dynids->list);
 }

 static void
 pci_free_dynids(struct pci_driver *drv)
 {
 	struct list_head *pos, *n;
 	struct dynid *dynid;

 	spin_lock(&drv->dynids.lock);
 	list_for_each_safe(pos, n, &drv->dynids.list) {
 		dynid = list_entry(pos, struct dynid, node);
 		list_del(&dynid->node);
 		kfree(dynid);
 	}
 	spin_unlock(&drv->dynids.lock);
 }

 static int
 pci_create_newid_file(struct pci_driver *drv)
 {
 	int error = 0;
 	if (drv->probe != NULL)
 		error = sysfs_create_file(&drv->driver.kobj,
 					  &driver_attr_new_id.attr);
 	return error;
 }

 static int
 pci_bus_match_dynids(const struct pci_dev *pci_dev, struct pci_driver *pci_drv)
 {
 	struct list_head *pos;
 	struct dynid *dynid;

 	spin_lock(&pci_drv->dynids.lock);
 	list_for_each(pos, &pci_drv->dynids.list) {
 		dynid = list_entry(pos, struct dynid, node);
 		if (pci_match_one_device(&dynid->id, pci_dev)) {
 			spin_unlock(&pci_drv->dynids.lock);
 			return 1;
 		}
 	}
 	spin_unlock(&pci_drv->dynids.lock);
 	return 0;
 }

 #else /* !CONFIG_HOTPLUG */
 static inline int pci_device_probe_dynamic(struct pci_driver *drv, struct pci_dev *pci_dev)
 {
 	return -ENODEV;
 }
 static inline void pci_init_dynids(struct pci_dynids *dynids) {}
 static inline void pci_free_dynids(struct pci_driver *drv) {}
 static inline int pci_create_newid_file(struct pci_driver *drv)
 {
 	return 0;
 }
 static inline int pci_bus_match_dynids(const struct pci_dev *pci_dev, struct pci_driver *pci_drv)
 {
 	return 0;
 }
 #endif

 /**
  * pci_match_device - Tell if a PCI device structure has a matching
  *                    PCI device id structure
  * @ids: array of PCI device id structures to search in
  * @dev: the PCI device structure to match against
  *
  * Used by a driver to check whether a PCI device present in the
  * system is in its list of supported devices.Returns the matching
  * pci_device_id structure or %NULL if there is no match.
  */
 const struct pci_device_id *
 pci_match_device(const struct pci_device_id *ids, const struct pci_dev *dev)
 {
 	while (ids->vendor || ids->subvendor || ids->class_mask) {
 		if (pci_match_one_device(ids, dev))
 			return ids;
 		ids++;
 	}
 	return NULL;
 }

 /**
  * pci_device_probe_static()
  *
  * returns 0 and sets pci_dev->driver when drv claims pci_dev, else error.
  */
 static int
 pci_device_probe_static(struct pci_driver *drv, struct pci_dev *pci_dev)
 {
 	int error = -ENODEV;
 	const struct pci_device_id *id;

 	if (!drv->id_table)
 		return error;
 	id = pci_match_device(drv->id_table, pci_dev);
 	if (id)
 		error = drv->probe(pci_dev, id);
 	if (error >= 0) {
 		pci_dev->driver = drv;
 		error = 0;
 	}
 	return error;
 }

 /**
  * __pci_device_probe()
  *
  * returns 0  on success, else error.
  * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
  */
 static int
 __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
 {
 	int error = 0;

 	if (!pci_dev->driver && drv->probe) {
 		error = pci_device_probe_static(drv, pci_dev);
 		if (error == -ENODEV)
 			error = pci_device_probe_dynamic(drv, pci_dev);
 	}
 	return error;
 }

 static int pci_device_probe(struct device * dev)
 {
 	int error = 0;
 	struct pci_driver *drv;
 	struct pci_dev *pci_dev;

 	drv = to_pci_driver(dev->driver);
 	pci_dev = to_pci_dev(dev);
 	pci_dev_get(pci_dev);
 	error = __pci_device_probe(drv, pci_dev);
 	if (error)
 		pci_dev_put(pci_dev);

 	return error;
 }

 static int pci_device_remove(struct device * dev)
 {
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;

 	if (drv) {
 		if (drv->remove)
 			drv->remove(pci_dev);
 		pci_dev->driver = NULL;
 	}

 	/*
 	 * We would love to complain here if pci_dev->is_enabled is set, that
 	 * the driver should have called pci_disable_device(), but the
 	 * unfortunate fact is there are too many odd BIOS and bridge setups
 	 * that don't like drivers doing that all of the time.
 	 * Oh well, we can dream of sane hardware when we sleep, no matter how
 	 * horrible the crap we have to deal with is when we are awake...
 	 */

 	pci_dev_put(pci_dev);
 	return 0;
 }

 static int pci_device_suspend(struct device * dev, pm_message_t state)
 {
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;
 	int i = 0;

 	if (drv && drv->suspend)
 		i = drv->suspend(pci_dev, state);
 	else
 		pci_save_state(pci_dev);
 	return i;
 }


 /*
  * Default resume method for devices that have no driver provided resume,
  * or not even a driver at all.
  */
 static void pci_default_resume(struct pci_dev *pci_dev)
 {
 	/* restore the PCI config space */
 	pci_restore_state(pci_dev);
 	/* if the device was enabled before suspend, reenable */
 	if (pci_dev->is_enabled)
 		pci_enable_device(pci_dev);
 	/* if the device was busmaster before the suspend, make it busmaster again */
 	if (pci_dev->is_busmaster)
 		pci_set_master(pci_dev);
 }

 static int pci_device_resume(struct device * dev)
 {
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;

 	if (drv && drv->resume)
 		drv->resume(pci_dev);
 	else
 		pci_default_resume(pci_dev);
 	return 0;
 }


 #define kobj_to_pci_driver(obj) container_of(obj, struct device_driver, kobj)
 #define attr_to_driver_attribute(obj) container_of(obj, struct driver_attribute, attr)

 static ssize_t
 pci_driver_attr_show(struct kobject * kobj, struct attribute *attr, char *buf)
 {
 	struct device_driver *driver = kobj_to_pci_driver(kobj);
 	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
 	ssize_t ret = 0;

 	if (get_driver(driver)) {
 		if (dattr->show)
 			ret = dattr->show(driver, buf);
 		put_driver(driver);
 	}
 	return ret;
 }

 static ssize_t
 pci_driver_attr_store(struct kobject * kobj, struct attribute *attr,
 		      const char *buf, size_t count)
 {
 	struct device_driver *driver = kobj_to_pci_driver(kobj);
 	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
 	ssize_t ret = 0;

 	if (get_driver(driver)) {
 		if (dattr->store)
 			ret = dattr->store(driver, buf, count);
 		put_driver(driver);
 	}
 	return ret;
 }

 static struct sysfs_ops pci_driver_sysfs_ops = {
 	.show = pci_driver_attr_show,
 	.store = pci_driver_attr_store,
 };
 static struct kobj_type pci_driver_kobj_type = {
 	.sysfs_ops = &pci_driver_sysfs_ops,
 };

 static int
 pci_populate_driver_dir(struct pci_driver *drv)
 {
 	return pci_create_newid_file(drv);
 }

 /**
  * pci_register_driver - register a new pci driver
  * @drv: the driver structure to register
  *
  * Adds the driver structure to the list of registered drivers.
  * Returns a negative value on error, otherwise 0.
  * If no error occured, the driver remains registered even if
  * no device was claimed during registration.
  */
 int pci_register_driver(struct pci_driver *drv)
 {
 	int error;

 	/* initialize common driver fields */
 	drv->driver.name = drv->name;
 	drv->driver.bus = &pci_bus_type;
 	drv->driver.probe = pci_device_probe;
 	drv->driver.remove = pci_device_remove;
 	drv->driver.owner = drv->owner;
 	drv->driver.kobj.ktype = &pci_driver_kobj_type;
 	pci_init_dynids(&drv->dynids);

 	/* register with core */
 	error = driver_register(&drv->driver);

 	if (!error)
 		pci_populate_driver_dir(drv);

 	return error;
 }

 /**
  * pci_unregister_driver - unregister a pci driver
  * @drv: the driver structure to unregister
  *
  * Deletes the driver structure from the list of registered PCI drivers,
  * gives it a chance to clean up by calling its remove() function for
  * each device it was responsible for, and marks those devices as
  * driverless.
  */

 void
 pci_unregister_driver(struct pci_driver *drv)
 {
 	driver_unregister(&drv->driver);
 	pci_free_dynids(drv);
 }

 static struct pci_driver pci_compat_driver = {
 	.name = "compat"
 };

 /**
  * pci_dev_driver - get the pci_driver of a device
  * @dev: the device to query
  *
  * Returns the appropriate pci_driver structure or %NULL if there is no
  * registered driver for the device.
  */
 struct pci_driver *
 pci_dev_driver(const struct pci_dev *dev)
 {
 	if (dev->driver)
 		return dev->driver;
 	else {
 		int i;
 		for(i=0; i<=PCI_ROM_RESOURCE; i++)
 			if (dev->resource[i].flags & IORESOURCE_BUSY)
 				return &pci_compat_driver;
 	}
 	return NULL;
 }

 /**
  * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
  * @ids: array of PCI device id structures to search in
  * @dev: the PCI device structure to match against
  *
  * Used by a driver to check whether a PCI device present in the
  * system is in its list of supported devices.Returns the matching
  * pci_device_id structure or %NULL if there is no match.
  */
 static int pci_bus_match(struct device * dev, struct device_driver * drv)
 {
 	const struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * pci_drv = to_pci_driver(drv);
 	const struct pci_device_id * ids = pci_drv->id_table;
 	const struct pci_device_id *found_id;

 	if (!ids)
 		return 0;

 	found_id = pci_match_device(ids, pci_dev);
 	if (found_id)
 		return 1;

 	return pci_bus_match_dynids(pci_dev, pci_drv);
 }

 /**
  * pci_dev_get - increments the reference count of the pci device structure
  * @dev: the device being referenced
  *
  * Each live reference to a device should be refcounted.
  *
  * Drivers for PCI devices should normally record such references in
  * their probe() methods, when they bind to a device, and release
  * them by calling pci_dev_put(), in their disconnect() methods.
  *
  * A pointer to the device with the incremented reference counter is returned.
  */
 struct pci_dev *pci_dev_get(struct pci_dev *dev)
 {
 	if (dev)
 		get_device(&dev->dev);
 	return dev;
 }

 /**
  * pci_dev_put - release a use of the pci device structure
  * @dev: device that's been disconnected
  *
  * Must be called when a user of a device is finished with it.  When the last
  * user of the device calls this function, the memory of the device is freed.
  */
 void pci_dev_put(struct pci_dev *dev)
 {
 	if (dev)
 		put_device(&dev->dev);
 }

 #ifndef CONFIG_HOTPLUG
 int pci_hotplug (struct device *dev, char **envp, int num_envp,
 		 char *buffer, int buffer_size)
 {
 	return -ENODEV;
 }
 #endif

 struct bus_type pci_bus_type = {
 	.name		= "pci",
 	.match		= pci_bus_match,
 	.hotplug	= pci_hotplug,
 	.suspend	= pci_device_suspend,
 	.resume		= pci_device_resume,
 	.dev_attrs	= pci_dev_attrs,
 };

 static int __init pci_driver_init(void)
 {
 	return bus_register(&pci_bus_type);
 }

 postcore_initcall(pci_driver_init);

 EXPORT_SYMBOL(pci_match_device);
 EXPORT_SYMBOL(pci_register_driver);
 EXPORT_SYMBOL(pci_unregister_driver);
 EXPORT_SYMBOL(pci_dev_driver);
 EXPORT_SYMBOL(pci_bus_type);
 EXPORT_SYMBOL(pci_dev_get);
 EXPORT_SYMBOL(pci_dev_put);
	/*
	* drivers/pci/pci-driver.c
	*
	*/

	#include <linux/pci.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/pci-dynids.h>
	#include "pci.h"

	/*
	* Registration of PCI drivers and handling of hot-pluggable devices.
	*/

	/*
	* Dynamic device IDs are disabled for !CONFIG_HOTPLUG
	*/

	#ifdef CONFIG_HOTPLUG
	/**
	* pci_device_probe_dynamic()
	*
	* Walk the dynamic ID list looking for a match.
	* returns 0 and sets pci_dev->driver when drv claims pci_dev, else error.
	*/
	static int
	pci_device_probe_dynamic(struct pci_driver drv, struct pci_dev pci_dev)
	{
	int error = -ENODEV;
	struct list_head *pos;
	struct dynid *dynid;

	spin_lock(&drv->dynids.lock);
	list_for_each(pos, &drv->dynids.list) {
	dynid = list_entry(pos, struct dynid, node);
	if (pci_match_one_device(&dynid->id, pci_dev)) {
	spin_unlock(&drv->dynids.lock);
	error = drv->probe(pci_dev, &dynid->id);
	if (error >= 0) {
	pci_dev->driver = drv;
	return 0;
	}
	return error;
	}
	}
	spin_unlock(&drv->dynids.lock);
	return error;
	}

	/**
	* store_new_id
	*
	* Adds a new dynamic pci device ID to this driver,
	* and causes the driver to probe for all devices again.
	*/
	static inline ssize_t
	store_new_id(struct device_driver driver, const char buf, size_t count)
	{
	struct dynid *dynid;
	struct bus_type * bus;
	struct pci_driver *pdrv = to_pci_driver(driver);
	__u32 vendor=PCI_ANY_ID, device=PCI_ANY_ID, subvendor=PCI_ANY_ID,
	subdevice=PCI_ANY_ID, class=0, class_mask=0;
	unsigned long driver_data=0;
	int fields=0;

	fields = sscanf(buf, "%x %x %x %x %x %x %lux",
	&vendor, &device, &subvendor, &subdevice,
	&class, &class_mask, &driver_data);
	if (fields < 0)
	return -EINVAL;

	dynid = kmalloc(sizeof(*dynid), GFP_KERNEL);
	if (!dynid)
	return -ENOMEM;

	memset(dynid, 0, sizeof(*dynid));
	INIT_LIST_HEAD(&dynid->node);
	dynid->id.vendor = vendor;
	dynid->id.device = device;
	dynid->id.subvendor = subvendor;
	dynid->id.subdevice = subdevice;
	dynid->id.class = class;
	dynid->id.class_mask = class_mask;
	dynid->id.driver_data = pdrv->dynids.use_driver_data ?
	driver_data : 0UL;

	spin_lock(&pdrv->dynids.lock);
	list_add_tail(&pdrv->dynids.list, &dynid->node);
	spin_unlock(&pdrv->dynids.lock);

	bus = get_bus(pdrv->driver.bus);
	if (bus) {
	if (get_driver(&pdrv->driver)) {
	down_write(&bus->subsys.rwsem);
	driver_attach(&pdrv->driver);
	up_write(&bus->subsys.rwsem);
	put_driver(&pdrv->driver);
	}
	put_bus(bus);
	}

	return count;
	}

	static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);
	static inline void
	pci_init_dynids(struct pci_dynids *dynids)
	{
	spin_lock_init(&dynids->lock);
	INIT_LIST_HEAD(&dynids->list);
	}

	static void
	pci_free_dynids(struct pci_driver *drv)
	{
	struct list_head pos, n;
	struct dynid *dynid;

	spin_lock(&drv->dynids.lock);
	list_for_each_safe(pos, n, &drv->dynids.list) {
	dynid = list_entry(pos, struct dynid, node);
	list_del(&dynid->node);
	kfree(dynid);
	}
	spin_unlock(&drv->dynids.lock);
	}

	static int
	pci_create_newid_file(struct pci_driver *drv)
	{
	int error = 0;
	if (drv->probe != NULL)
	error = sysfs_create_file(&drv->driver.kobj,
	&driver_attr_new_id.attr);
	return error;
	}

	static int
	pci_bus_match_dynids(const struct pci_dev pci_dev, struct pci_driver pci_drv)
	{
	struct list_head *pos;
	struct dynid *dynid;

	spin_lock(&pci_drv->dynids.lock);
	list_for_each(pos, &pci_drv->dynids.list) {
	dynid = list_entry(pos, struct dynid, node);
	if (pci_match_one_device(&dynid->id, pci_dev)) {
	spin_unlock(&pci_drv->dynids.lock);
	return 1;
	}
	}
	spin_unlock(&pci_drv->dynids.lock);
	return 0;
	}

	#else /* !CONFIG_HOTPLUG */
	static inline int pci_device_probe_dynamic(struct pci_driver drv, struct pci_dev pci_dev)
	{
	return -ENODEV;
	}
	static inline void pci_init_dynids(struct pci_dynids *dynids) {}
	static inline void pci_free_dynids(struct pci_driver *drv) {}
	static inline int pci_create_newid_file(struct pci_driver *drv)
	{
	return 0;
	}
	static inline int pci_bus_match_dynids(const struct pci_dev pci_dev, struct pci_driver pci_drv)
	{
	return 0;
	}
	#endif

	/**
	* pci_match_device - Tell if a PCI device structure has a matching
	* PCI device id structure
	* @ids: array of PCI device id structures to search in
	* @dev: the PCI device structure to match against
	*
	* Used by a driver to check whether a PCI device present in the
	* system is in its list of supported devices.Returns the matching
	* pci_device_id structure or %NULL if there is no match.
	*/
	const struct pci_device_id *
	pci_match_device(const struct pci_device_id ids, const struct pci_dev dev)
	{
	while (ids->vendor \|\| ids->subvendor \|\| ids->class_mask) {
	if (pci_match_one_device(ids, dev))
	return ids;
	ids++;
	}
	return NULL;
	}

	/**
	* pci_device_probe_static()
	*
	* returns 0 and sets pci_dev->driver when drv claims pci_dev, else error.
	*/
	static int
	pci_device_probe_static(struct pci_driver drv, struct pci_dev pci_dev)
	{
	int error = -ENODEV;
	const struct pci_device_id *id;

	if (!drv->id_table)
	return error;
	id = pci_match_device(drv->id_table, pci_dev);
	if (id)
	error = drv->probe(pci_dev, id);
	if (error >= 0) {
	pci_dev->driver = drv;
	error = 0;
	}
	return error;
	}

	/**
	* __pci_device_probe()
	*
	* returns 0 on success, else error.
	* side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
	*/
	static int
	__pci_device_probe(struct pci_driver drv, struct pci_dev pci_dev)
	{
	int error = 0;

	if (!pci_dev->driver && drv->probe) {
	error = pci_device_probe_static(drv, pci_dev);
	if (error == -ENODEV)
	error = pci_device_probe_dynamic(drv, pci_dev);
	}
	return error;
	}

	static int pci_device_probe(struct device * dev)
	{
	int error = 0;
	struct pci_driver *drv;
	struct pci_dev *pci_dev;

	drv = to_pci_driver(dev->driver);
	pci_dev = to_pci_dev(dev);
	pci_dev_get(pci_dev);
	error = __pci_device_probe(drv, pci_dev);
	if (error)
	pci_dev_put(pci_dev);

	return error;
	}

	static int pci_device_remove(struct device * dev)
	{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	if (drv) {
	if (drv->remove)
	drv->remove(pci_dev);
	pci_dev->driver = NULL;
	}

	/*
	* We would love to complain here if pci_dev->is_enabled is set, that
	* the driver should have called pci_disable_device(), but the
	* unfortunate fact is there are too many odd BIOS and bridge setups
	* that don't like drivers doing that all of the time.
	* Oh well, we can dream of sane hardware when we sleep, no matter how
	* horrible the crap we have to deal with is when we are awake...
	*/

	pci_dev_put(pci_dev);
	return 0;
	}

	static int pci_device_suspend(struct device * dev, pm_message_t state)
	{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;
	int i = 0;

	if (drv && drv->suspend)
	i = drv->suspend(pci_dev, state);
	else
	pci_save_state(pci_dev);
	return i;
	}


	/*
	* Default resume method for devices that have no driver provided resume,
	* or not even a driver at all.
	*/
	static void pci_default_resume(struct pci_dev *pci_dev)
	{
	/* restore the PCI config space */
	pci_restore_state(pci_dev);
	/* if the device was enabled before suspend, reenable */
	if (pci_dev->is_enabled)
	pci_enable_device(pci_dev);
	/* if the device was busmaster before the suspend, make it busmaster again */
	if (pci_dev->is_busmaster)
	pci_set_master(pci_dev);
	}

	static int pci_device_resume(struct device * dev)
	{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	if (drv && drv->resume)
	drv->resume(pci_dev);
	else
	pci_default_resume(pci_dev);
	return 0;
	}


	#define kobj_to_pci_driver(obj) container_of(obj, struct device_driver, kobj)
	#define attr_to_driver_attribute(obj) container_of(obj, struct driver_attribute, attr)

	static ssize_t
	pci_driver_attr_show(struct kobject * kobj, struct attribute attr, char buf)
	{
	struct device_driver *driver = kobj_to_pci_driver(kobj);
	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
	ssize_t ret = 0;

	if (get_driver(driver)) {
	if (dattr->show)
	ret = dattr->show(driver, buf);
	put_driver(driver);
	}
	return ret;
	}

	static ssize_t
	pci_driver_attr_store(struct kobject * kobj, struct attribute *attr,
	const char *buf, size_t count)
	{
	struct device_driver *driver = kobj_to_pci_driver(kobj);
	struct driver_attribute *dattr = attr_to_driver_attribute(attr);
	ssize_t ret = 0;

	if (get_driver(driver)) {
	if (dattr->store)
	ret = dattr->store(driver, buf, count);
	put_driver(driver);
	}
	return ret;
	}

	static struct sysfs_ops pci_driver_sysfs_ops = {
	.show = pci_driver_attr_show,
	.store = pci_driver_attr_store,
	};
	static struct kobj_type pci_driver_kobj_type = {
	.sysfs_ops = &pci_driver_sysfs_ops,
	};

	static int
	pci_populate_driver_dir(struct pci_driver *drv)
	{
	return pci_create_newid_file(drv);
	}

	/**
	* pci_register_driver - register a new pci driver
	* @drv: the driver structure to register
	*
	* Adds the driver structure to the list of registered drivers.
	* Returns a negative value on error, otherwise 0.
	* If no error occured, the driver remains registered even if
	* no device was claimed during registration.
	*/
	int pci_register_driver(struct pci_driver *drv)
	{
	int error;

	/* initialize common driver fields */
	drv->driver.name = drv->name;
	drv->driver.bus = &pci_bus_type;
	drv->driver.probe = pci_device_probe;
	drv->driver.remove = pci_device_remove;
	drv->driver.owner = drv->owner;
	drv->driver.kobj.ktype = &pci_driver_kobj_type;
	pci_init_dynids(&drv->dynids);

	/* register with core */
	error = driver_register(&drv->driver);

	if (!error)
	pci_populate_driver_dir(drv);

	return error;
	}

	/**
	* pci_unregister_driver - unregister a pci driver
	* @drv: the driver structure to unregister
	*
	* Deletes the driver structure from the list of registered PCI drivers,
	* gives it a chance to clean up by calling its remove() function for
	* each device it was responsible for, and marks those devices as
	* driverless.
	*/

	void
	pci_unregister_driver(struct pci_driver *drv)
	{
	driver_unregister(&drv->driver);
	pci_free_dynids(drv);
	}

	static struct pci_driver pci_compat_driver = {
	.name = "compat"
	};

	/**
	* pci_dev_driver - get the pci_driver of a device
	* @dev: the device to query
	*
	* Returns the appropriate pci_driver structure or %NULL if there is no
	* registered driver for the device.
	*/
	struct pci_driver *
	pci_dev_driver(const struct pci_dev *dev)
	{
	if (dev->driver)
	return dev->driver;
	else {
	int i;
	for(i=0; i<=PCI_ROM_RESOURCE; i++)
	if (dev->resource[i].flags & IORESOURCE_BUSY)
	return &pci_compat_driver;
	}
	return NULL;
	}

	/**
	* pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
	* @ids: array of PCI device id structures to search in
	* @dev: the PCI device structure to match against
	*
	* Used by a driver to check whether a PCI device present in the
	* system is in its list of supported devices.Returns the matching
	* pci_device_id structure or %NULL if there is no match.
	*/
	static int pci_bus_match(struct device * dev, struct device_driver * drv)
	{
	const struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * pci_drv = to_pci_driver(drv);
	const struct pci_device_id * ids = pci_drv->id_table;
	const struct pci_device_id *found_id;

	if (!ids)
	return 0;

	found_id = pci_match_device(ids, pci_dev);
	if (found_id)
	return 1;

	return pci_bus_match_dynids(pci_dev, pci_drv);
	}

	/**
	* pci_dev_get - increments the reference count of the pci device structure
	* @dev: the device being referenced
	*
	* Each live reference to a device should be refcounted.
	*
	* Drivers for PCI devices should normally record such references in
	* their probe() methods, when they bind to a device, and release
	* them by calling pci_dev_put(), in their disconnect() methods.
	*
	* A pointer to the device with the incremented reference counter is returned.
	*/
	struct pci_dev pci_dev_get(struct pci_dev dev)
	{
	if (dev)
	get_device(&dev->dev);
	return dev;
	}

	/**
	* pci_dev_put - release a use of the pci device structure
	* @dev: device that's been disconnected
	*
	* Must be called when a user of a device is finished with it. When the last
	* user of the device calls this function, the memory of the device is freed.
	*/
	void pci_dev_put(struct pci_dev *dev)
	{
	if (dev)
	put_device(&dev->dev);
	}

	#ifndef CONFIG_HOTPLUG
	int pci_hotplug (struct device dev, char *envp, int num_envp,
	char *buffer, int buffer_size)
	{
	return -ENODEV;
	}
	#endif

	struct bus_type pci_bus_type = {
	.name = "pci",
	.match = pci_bus_match,
	.hotplug = pci_hotplug,
	.suspend = pci_device_suspend,
	.resume = pci_device_resume,
	.dev_attrs = pci_dev_attrs,
	};

	static int __init pci_driver_init(void)
	{
	return bus_register(&pci_bus_type);
	}

	postcore_initcall(pci_driver_init);

	EXPORT_SYMBOL(pci_match_device);
	EXPORT_SYMBOL(pci_register_driver);
	EXPORT_SYMBOL(pci_unregister_driver);
	EXPORT_SYMBOL(pci_dev_driver);
	EXPORT_SYMBOL(pci_bus_type);
	EXPORT_SYMBOL(pci_dev_get);
	EXPORT_SYMBOL(pci_dev_put);