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Commit 7e27780f authored by Sarah Bailey's avatar Sarah Bailey Committed by Greg Kroah-Hartman
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USB: added dynamic major number for USB endpoints 

This patch is an update for Greg K-H's proposed usbfs2:
http://sourceforge.net/mailarchive/message.php?msg_id=19295229



It creates a dynamic major for USB endpoints and fixes
the endpoint minor calculation.

Signed-off-by: default avatarSarah Bailey <saharabeara@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 10c8211c

drivers/usb/core/endpoint.c

+85 −13
Original line number Diff line number Diff line
@@ -10,15 +10,20 @@ 
 */



#include <linux/kernel.h>

#include <linux/spinlock.h>

#include <linux/idr.h>

#include <linux/usb.h>

#include "usb.h"



/* endpoint stuff */

#define MAX_ENDPOINT_MINORS (64*128*32)

static int usb_endpoint_major;

static DEFINE_IDR(endpoint_idr);



struct ep_device {

	struct usb_endpoint_descriptor *desc;

	struct usb_device *udev;

	struct device dev;

	int minor;

};

#define to_ep_device(_dev) \

	container_of(_dev, struct ep_device, dev)
@@ -152,6 +157,55 @@ static struct attribute_group ep_dev_attr_grp = { 
	.attrs = ep_dev_attrs,

};



static int usb_endpoint_major_init(void)

{

	dev_t dev;

	int error;



	error = alloc_chrdev_region(&dev, 0, MAX_ENDPOINT_MINORS,

				    "usb_endpoint");

	if (error) {

		err("unable to get a dynamic major for usb endpoints");

		return error;

	}

	usb_endpoint_major = MAJOR(dev);



	return error;

}



static void usb_endpoint_major_cleanup(void)

{

	unregister_chrdev_region(MKDEV(usb_endpoint_major, 0),

				 MAX_ENDPOINT_MINORS);

}



static int endpoint_get_minor(struct ep_device *ep_dev)

{

	static DEFINE_MUTEX(minor_lock);

	int retval = -ENOMEM;

	int id;



	mutex_lock(&minor_lock);

	if (idr_pre_get(&endpoint_idr, GFP_KERNEL) == 0)

		goto exit;



	retval = idr_get_new(&endpoint_idr, ep_dev, &id);

	if (retval < 0) {

		if (retval == -EAGAIN)

			retval = -ENOMEM;

		goto exit;

	}

	ep_dev->minor = id & MAX_ID_MASK;

exit:

	mutex_unlock(&minor_lock);

	return retval;

}



static void endpoint_free_minor(struct ep_device *ep_dev)

{

	idr_remove(&endpoint_idr, ep_dev->minor);

}



static struct endpoint_class {

	struct kref kref;

	struct class *class;
@@ -176,11 +230,20 @@ static int init_endpoint_class(void) 
	ep_class->class = class_create(THIS_MODULE, "usb_endpoint");

	if (IS_ERR(ep_class->class)) {

		result = IS_ERR(ep_class->class);

		kfree(ep_class);

		ep_class = NULL;

		goto exit;

		goto class_create_error;

	}



	result = usb_endpoint_major_init();

	if (result)

		goto endpoint_major_error;



	goto exit;



endpoint_major_error:

	class_destroy(ep_class->class);

class_create_error:

	kfree(ep_class);

	ep_class = NULL;

exit:

	return result;

}
@@ -191,6 +254,7 @@ static void release_endpoint_class(struct kref *kref) 
	class_destroy(ep_class->class);

	kfree(ep_class);

	ep_class = NULL;

	usb_endpoint_major_cleanup();

}



static void destroy_endpoint_class(void)
@@ -213,7 +277,6 @@ int usb_create_ep_files(struct device *parent, 
{

	char name[8];

	struct ep_device *ep_dev;

	int minor;

	int retval;



	retval = init_endpoint_class();
@@ -226,12 +289,16 @@ int usb_create_ep_files(struct device *parent, 
		goto error_alloc;

	}



	/* fun calculation to determine the minor of this endpoint */

	minor = (((udev->bus->busnum - 1) * 128) * 16) + (udev->devnum - 1);

	retval = endpoint_get_minor(ep_dev);

	if (retval) {

		dev_err(parent, "can not allocate minor number for %s",

			ep_dev->dev.bus_id);

		goto error_register;

	}



	ep_dev->desc = &endpoint->desc;

	ep_dev->udev = udev;

	ep_dev->dev.devt = MKDEV(442, minor);	// FIXME fake number...

	ep_dev->dev.devt = MKDEV(usb_endpoint_major, ep_dev->minor);

	ep_dev->dev.class = ep_class->class;

	ep_dev->dev.parent = parent;

	ep_dev->dev.release = ep_device_release;
@@ -241,7 +308,7 @@ int usb_create_ep_files(struct device *parent, 


	retval = device_register(&ep_dev->dev);

	if (retval)

		goto error_register;

		goto error_chrdev;

	retval = sysfs_create_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);

	if (retval)

		goto error_group;
@@ -261,6 +328,9 @@ error_group: 
	destroy_endpoint_class();

	return retval;



error_chrdev:

	endpoint_free_minor(ep_dev);



error_register:

	kfree(ep_dev);

error_alloc:
@@ -271,14 +341,16 @@ exit: 


void usb_remove_ep_files(struct usb_host_endpoint *endpoint)

{

	struct ep_device *ep_dev = endpoint->ep_dev;



	if (endpoint->ep_dev) {

	if (ep_dev) {

		char name[8];



		sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);

		sysfs_remove_link(&endpoint->ep_dev->dev.parent->kobj, name);

		sysfs_remove_group(&endpoint->ep_dev->dev.kobj, &ep_dev_attr_grp);

		device_unregister(&endpoint->ep_dev->dev);

		sysfs_remove_link(&ep_dev->dev.parent->kobj, name);

		sysfs_remove_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);

		endpoint_free_minor(ep_dev);

		device_unregister(&ep_dev->dev);

		endpoint->ep_dev = NULL;

		destroy_endpoint_class();

	}