linux/drivers/usb/core/endpoint.c
Alan Stern 2e5f10e4f0 USB: create attributes before sending uevent
This patch (as1087d) fixes a long-standing problem in usbcore: Device,
interface, and endpoint attributes aren't added until _after_ the
creation uevent has already been broadcast.

Unfortunately there are a few attributes which cannot be created that
early.  The "descriptors" attribute is binary and so must be created
separately.  The power-management attributes can't be created until
the dev/power/ group exists.  And the interface string can vary from
one altsetting to another, so it has to be created dynamically.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-14 10:00:26 -07:00

356 lines
8.1 KiB
C

/*
* drivers/usb/core/endpoint.c
*
* (C) Copyright 2002,2004,2006 Greg Kroah-Hartman
* (C) Copyright 2002,2004 IBM Corp.
* (C) Copyright 2006 Novell Inc.
*
* Endpoint sysfs stuff
*
*/
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <linux/usb.h>
#include "usb.h"
#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)
struct ep_attribute {
struct attribute attr;
ssize_t (*show)(struct usb_device *,
struct usb_endpoint_descriptor *, char *);
};
#define to_ep_attribute(_attr) \
container_of(_attr, struct ep_attribute, attr)
#define usb_ep_attr(field, format_string) \
static ssize_t show_ep_##field(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
struct ep_device *ep = to_ep_device(dev); \
return sprintf(buf, format_string, ep->desc->field); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_ep_##field, NULL);
usb_ep_attr(bLength, "%02x\n")
usb_ep_attr(bEndpointAddress, "%02x\n")
usb_ep_attr(bmAttributes, "%02x\n")
usb_ep_attr(bInterval, "%02x\n")
static ssize_t show_ep_wMaxPacketSize(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ep_device *ep = to_ep_device(dev);
return sprintf(buf, "%04x\n",
le16_to_cpu(ep->desc->wMaxPacketSize) & 0x07ff);
}
static DEVICE_ATTR(wMaxPacketSize, S_IRUGO, show_ep_wMaxPacketSize, NULL);
static ssize_t show_ep_type(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct ep_device *ep = to_ep_device(dev);
char *type = "unknown";
switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
case USB_ENDPOINT_XFER_CONTROL:
type = "Control";
break;
case USB_ENDPOINT_XFER_ISOC:
type = "Isoc";
break;
case USB_ENDPOINT_XFER_BULK:
type = "Bulk";
break;
case USB_ENDPOINT_XFER_INT:
type = "Interrupt";
break;
}
return sprintf(buf, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, show_ep_type, NULL);
static ssize_t show_ep_interval(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ep_device *ep = to_ep_device(dev);
char unit;
unsigned interval = 0;
unsigned in;
in = (ep->desc->bEndpointAddress & USB_DIR_IN);
switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
case USB_ENDPOINT_XFER_CONTROL:
if (ep->udev->speed == USB_SPEED_HIGH) /* uframes per NAK */
interval = ep->desc->bInterval;
break;
case USB_ENDPOINT_XFER_ISOC:
interval = 1 << (ep->desc->bInterval - 1);
break;
case USB_ENDPOINT_XFER_BULK:
if (ep->udev->speed == USB_SPEED_HIGH && !in) /* uframes per NAK */
interval = ep->desc->bInterval;
break;
case USB_ENDPOINT_XFER_INT:
if (ep->udev->speed == USB_SPEED_HIGH)
interval = 1 << (ep->desc->bInterval - 1);
else
interval = ep->desc->bInterval;
break;
}
interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
if (interval % 1000)
unit = 'u';
else {
unit = 'm';
interval /= 1000;
}
return sprintf(buf, "%d%cs\n", interval, unit);
}
static DEVICE_ATTR(interval, S_IRUGO, show_ep_interval, NULL);
static ssize_t show_ep_direction(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ep_device *ep = to_ep_device(dev);
char *direction;
if ((ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
USB_ENDPOINT_XFER_CONTROL)
direction = "both";
else if (ep->desc->bEndpointAddress & USB_DIR_IN)
direction = "in";
else
direction = "out";
return sprintf(buf, "%s\n", direction);
}
static DEVICE_ATTR(direction, S_IRUGO, show_ep_direction, NULL);
static struct attribute *ep_dev_attrs[] = {
&dev_attr_bLength.attr,
&dev_attr_bEndpointAddress.attr,
&dev_attr_bmAttributes.attr,
&dev_attr_bInterval.attr,
&dev_attr_wMaxPacketSize.attr,
&dev_attr_interval.attr,
&dev_attr_type.attr,
&dev_attr_direction.attr,
NULL,
};
static struct attribute_group ep_dev_attr_grp = {
.attrs = ep_dev_attrs,
};
static struct attribute_group *ep_dev_groups[] = {
&ep_dev_attr_grp,
NULL
};
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;
} *ep_class;
static int init_endpoint_class(void)
{
int result = 0;
if (ep_class != NULL) {
kref_get(&ep_class->kref);
goto exit;
}
ep_class = kmalloc(sizeof(*ep_class), GFP_KERNEL);
if (!ep_class) {
result = -ENOMEM;
goto exit;
}
kref_init(&ep_class->kref);
ep_class->class = class_create(THIS_MODULE, "usb_endpoint");
if (IS_ERR(ep_class->class)) {
result = PTR_ERR(ep_class->class);
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;
}
static void release_endpoint_class(struct kref *kref)
{
/* Ok, we cheat as we know we only have one ep_class */
class_destroy(ep_class->class);
kfree(ep_class);
ep_class = NULL;
usb_endpoint_major_cleanup();
}
static void destroy_endpoint_class(void)
{
if (ep_class)
kref_put(&ep_class->kref, release_endpoint_class);
}
static void ep_device_release(struct device *dev)
{
struct ep_device *ep_dev = to_ep_device(dev);
endpoint_free_minor(ep_dev);
kfree(ep_dev);
}
int usb_create_ep_files(struct device *parent,
struct usb_host_endpoint *endpoint,
struct usb_device *udev)
{
char name[8];
struct ep_device *ep_dev;
int retval;
retval = init_endpoint_class();
if (retval)
goto exit;
ep_dev = kzalloc(sizeof(*ep_dev), GFP_KERNEL);
if (!ep_dev) {
retval = -ENOMEM;
goto error_alloc;
}
retval = endpoint_get_minor(ep_dev);
if (retval) {
dev_err(parent, "can not allocate minor number for %s\n",
ep_dev->dev.bus_id);
goto error_register;
}
ep_dev->desc = &endpoint->desc;
ep_dev->udev = udev;
ep_dev->dev.groups = ep_dev_groups;
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;
snprintf(ep_dev->dev.bus_id, BUS_ID_SIZE, "usbdev%d.%d_ep%02x",
udev->bus->busnum, udev->devnum,
endpoint->desc.bEndpointAddress);
retval = device_register(&ep_dev->dev);
if (retval)
goto error_chrdev;
/* create the symlink to the old-style "ep_XX" directory */
sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
retval = sysfs_create_link(&parent->kobj, &ep_dev->dev.kobj, name);
if (retval)
goto error_link;
endpoint->ep_dev = ep_dev;
return retval;
error_link:
device_unregister(&ep_dev->dev);
destroy_endpoint_class();
return retval;
error_chrdev:
endpoint_free_minor(ep_dev);
error_register:
kfree(ep_dev);
error_alloc:
destroy_endpoint_class();
exit:
return retval;
}
void usb_remove_ep_files(struct usb_host_endpoint *endpoint)
{
struct ep_device *ep_dev = endpoint->ep_dev;
if (ep_dev) {
char name[8];
sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
sysfs_remove_link(&ep_dev->dev.parent->kobj, name);
device_unregister(&ep_dev->dev);
endpoint->ep_dev = NULL;
destroy_endpoint_class();
}
}