[PATCH] USB: make endpoints real struct devices

This will allow for us to give endpoints a major/minor to create a
"usbfs2-like" way to access endpoints directly from userspace in an
easier manner than the current usbfs provides us.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/endpoint.c

@@ -14,13 +14,14 @@
 #include "usb.h"
 
 /* endpoint stuff */
-struct ep_object {
+
+struct ep_device {
 	struct usb_endpoint_descriptor *desc;
 	struct usb_device *udev;
-	struct kobject kobj;
+	struct device dev;
 };
-#define to_ep_object(_kobj) \
-	container_of(_kobj, struct ep_object, kobj)
+#define to_ep_device(_dev) \
+	container_of(_dev, struct ep_device, dev)
 
 struct ep_attribute {
 	struct attribute attr;
@@ -30,40 +31,37 @@ struct ep_attribute {
 #define to_ep_attribute(_attr) \
 	container_of(_attr, struct ep_attribute, attr)
 
-#define EP_ATTR(_name)						\
-struct ep_attribute ep_##_name = {				\
-	.attr = {.name = #_name, .owner = THIS_MODULE,		\
-			.mode = S_IRUGO},			\
-	.show = show_ep_##_name}
-
 #define usb_ep_attr(field, format_string)			\
-static ssize_t show_ep_##field(struct usb_device *udev,		\
-		struct usb_endpoint_descriptor *desc, 		\
-		char *buf)					\
+static ssize_t show_ep_##field(struct device *dev,		\
+			       struct device_attribute *attr,	\
+			       char *buf)			\
 {								\
-	return sprintf(buf, format_string, desc->field);	\
+	struct ep_device *ep = to_ep_device(dev);		\
+	return sprintf(buf, format_string, ep->desc->field);	\
 }								\
-static EP_ATTR(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 usb_device *udev,
-		struct usb_endpoint_descriptor *desc, char *buf)
+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(desc->wMaxPacketSize) & 0x07ff);
+			le16_to_cpu(ep->desc->wMaxPacketSize) & 0x07ff);
 }
-static EP_ATTR(wMaxPacketSize);
+static DEVICE_ATTR(wMaxPacketSize, S_IRUGO, show_ep_wMaxPacketSize, NULL);
 
-static ssize_t show_ep_type(struct usb_device *udev,
-		struct usb_endpoint_descriptor *desc, char *buf)
+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 (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+	switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
 	case USB_ENDPOINT_XFER_CONTROL:
 		type = "Control";
 		break;
@@ -79,37 +77,38 @@ static ssize_t show_ep_type(struct usb_device *udev,
 	}
 	return sprintf(buf, "%s\n", type);
 }
-static EP_ATTR(type);
+static DEVICE_ATTR(type, S_IRUGO, show_ep_type, NULL);
 
-static ssize_t show_ep_interval(struct usb_device *udev,
-		struct usb_endpoint_descriptor *desc, char *buf)
+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 = (desc->bEndpointAddress & USB_DIR_IN);
+	in = (ep->desc->bEndpointAddress & USB_DIR_IN);
 
-	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+	switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
 	case USB_ENDPOINT_XFER_CONTROL:
-		if (udev->speed == USB_SPEED_HIGH) 	/* uframes per NAK */
-			interval = desc->bInterval;
+		if (ep->udev->speed == USB_SPEED_HIGH) 	/* uframes per NAK */
+			interval = ep->desc->bInterval;
 		break;
 	case USB_ENDPOINT_XFER_ISOC:
-		interval = 1 << (desc->bInterval - 1);
+		interval = 1 << (ep->desc->bInterval - 1);
 		break;
 	case USB_ENDPOINT_XFER_BULK:
-		if (udev->speed == USB_SPEED_HIGH && !in) /* uframes per NAK */
-			interval = desc->bInterval;
+		if (ep->udev->speed == USB_SPEED_HIGH && !in) /* uframes per NAK */
+			interval = ep->desc->bInterval;
 		break;
 	case USB_ENDPOINT_XFER_INT:
-		if (udev->speed == USB_SPEED_HIGH)
-			interval = 1 << (desc->bInterval - 1);
+		if (ep->udev->speed == USB_SPEED_HIGH)
+			interval = 1 << (ep->desc->bInterval - 1);
 		else
-			interval = desc->bInterval;
+			interval = ep->desc->bInterval;
 		break;
 	}
-	interval *= (udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
+	interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
 	if (interval % 1000)
 		unit = 'u';
 	else {
@@ -119,95 +118,158 @@ static ssize_t show_ep_interval(struct usb_device *udev,
 
 	return sprintf(buf, "%d%cs\n", interval, unit);
 }
-static EP_ATTR(interval);
+static DEVICE_ATTR(interval, S_IRUGO, show_ep_interval, NULL);
 
-static ssize_t show_ep_direction(struct usb_device *udev,
-		struct usb_endpoint_descriptor *desc, char *buf)
+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 ((desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+	if ((ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 			USB_ENDPOINT_XFER_CONTROL)
 		direction = "both";
-	else if (desc->bEndpointAddress & USB_DIR_IN)
+	else if (ep->desc->bEndpointAddress & USB_DIR_IN)
 		direction = "in";
 	else
 		direction = "out";
 	return sprintf(buf, "%s\n", direction);
 }
-static EP_ATTR(direction);
-
-static struct attribute *ep_attrs[] = {
-	&ep_bLength.attr,
-	&ep_bEndpointAddress.attr,
-	&ep_bmAttributes.attr,
-	&ep_bInterval.attr,
-	&ep_wMaxPacketSize.attr,
-	&ep_type.attr,
-	&ep_interval.attr,
-	&ep_direction.attr,
+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 void ep_object_release(struct kobject *kobj)
+static struct endpoint_class {
+	struct kref kref;
+	struct class *class;
+} *ep_class;
+
+static int init_endpoint_class(void)
 {
-	kfree(to_ep_object(kobj));
+	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 = IS_ERR(ep_class->class);
+		kfree(ep_class);
+		ep_class = NULL;
+		goto exit;
+	}
+
+exit:
+	return result;
 }
 
-static ssize_t ep_object_show(struct kobject *kobj, struct attribute *attr,
-		char *buf)
+static void release_endpoint_class(struct kref *kref)
 {
-	struct ep_object *ep_obj = to_ep_object(kobj);
-	struct ep_attribute *ep_attr = to_ep_attribute(attr);
+	/* Ok, we cheat as we know we only have one ep_class */
+	class_destroy(ep_class->class);
+	kfree(ep_class);
+	ep_class = NULL;
+}
 
-	return (ep_attr->show)(ep_obj->udev, ep_obj->desc, buf);
+static void destroy_endpoint_class(void)
+{
+	if (ep_class)
+		kref_put(&ep_class->kref, release_endpoint_class);
 }
 
-static struct sysfs_ops ep_object_sysfs_ops = {
-	.show =			ep_object_show,
-};
+static void ep_device_release(struct device *dev)
+{
+	struct ep_device *ep_dev = to_ep_device(dev);
 
-static struct kobj_type ep_object_ktype = {
-	.release =		ep_object_release,
-	.sysfs_ops =		&ep_object_sysfs_ops,
-	.default_attrs =	ep_attrs,
-};
+	dev_dbg(dev, "%s called for %s\n", __FUNCTION__, dev->bus_id);
+	kfree(ep_dev);
+}
 
 void usb_create_ep_files(struct device *parent,
 			 struct usb_host_endpoint *endpoint,
 			 struct usb_device *udev)
 {
-	struct ep_object *ep_obj;
-	struct kobject *kobj;
+	char name[8];
+	struct ep_device *ep_dev;
+	int minor;
+	int retval;
+
+	retval = init_endpoint_class();
+	if (retval)
+		goto exit;
 
-	ep_obj = kzalloc(sizeof(struct ep_object), GFP_KERNEL);
-	if (!ep_obj)
-		return;
+	ep_dev = kzalloc(sizeof(*ep_dev), GFP_KERNEL);
+	if (!ep_dev) {
+		retval = -ENOMEM;
+		goto exit;
+	}
 
-	ep_obj->desc = &endpoint->desc;
-	ep_obj->udev = udev;
+	/* fun calculation to determine the minor of this endpoint */
+	minor = (((udev->bus->busnum - 1) * 128) * 16) + (udev->devnum - 1);
 
-	kobj = &ep_obj->kobj;
-	kobject_set_name(kobj, "ep_%02x", endpoint->desc.bEndpointAddress);
-	kobj->parent = &parent->kobj;
-	kobj->ktype = &ep_object_ktype;
+	ep_dev->desc = &endpoint->desc;
+	ep_dev->udev = udev;
+	ep_dev->dev.devt = MKDEV(442, minor);	// FIXME fake number...
+	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);
 
-	/* Don't use kobject_register, because it generates a hotplug event */
-	kobject_init(kobj);
-	if (kobject_add(kobj) == 0)
-		endpoint->kobj = kobj;
-	else
-		kobject_put(kobj);
+	retval = device_register(&ep_dev->dev);
+	if (retval)
+		goto error;
+	sysfs_create_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
+
+	endpoint->ep_dev = ep_dev;
+
+	/* create the symlink to the old-style "ep_XX" directory */
+	sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
+	sysfs_create_link(&parent->kobj, &endpoint->ep_dev->dev.kobj, name);
+
+exit:
+	return;
+error:
+	kfree(ep_dev);
+	return;
 }
 
 void usb_remove_ep_files(struct usb_host_endpoint *endpoint)
 {
 
-	if (endpoint->kobj) {
-		kobject_del(endpoint->kobj);
-		kobject_put(endpoint->kobj);
-		endpoint->kobj = NULL;
+	if (endpoint->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);
+		endpoint->ep_dev = NULL;
 	}
+	destroy_endpoint_class();
 }
 
 

include/linux/usb.h

@@ -40,6 +40,8 @@ struct usb_driver;
  * Devices may also have class-specific or vendor-specific descriptors.
  */
 
+struct ep_device;
+
 /**
  * struct usb_host_endpoint - host-side endpoint descriptor and queue
  * @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
@@ -57,7 +59,7 @@ struct usb_host_endpoint {
 	struct usb_endpoint_descriptor	desc;
 	struct list_head		urb_list;
 	void				*hcpriv;
-	struct kobject			*kobj;	/* For sysfs info */
+	struct ep_device 		*ep_dev;	/* For sysfs info */
 
 	unsigned char *extra;   /* Extra descriptors */
 	int extralen;