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Commit 165fe97e authored by Craig W. Nadler's avatar Craig W. Nadler Committed by Greg Kroah-Hartman
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USB: add IAD support to usbfs and sysfs 



USB_IAD: Adds support for USB Interface Association Descriptors.

This patch adds support to the USB host stack for parsing, storing, and
displaying Interface Association Descriptors. In /proc/bus/usb/devices
lines starting with A: show the fields in an IAD. In sysfs if an
interface on a USB device is referenced by an IAD the following files
will be added to the sysfs directory for that interface:
iad_bFirstInterface, iad_bInterfaceCount, iad_bFunctionClass, and
iad_bFunctionSubClass, iad_bFunctionProtocol

Signed-off-by: default avatarCraig W. Nadler <craig@nadler.us>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 50d2dc72

drivers/usb/core/config.c

+15 −0
Original line number Diff line number Diff line
@@ -295,6 +295,7 @@ static int usb_parse_configuration(struct device *ddev, int cfgidx, 
	struct usb_descriptor_header *header;

	int len, retval;

	u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];

	unsigned iad_num = 0;



	memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);

	if (config->desc.bDescriptorType != USB_DT_CONFIG ||
@@ -372,6 +373,20 @@ static int usb_parse_configuration(struct device *ddev, int cfgidx, 
				++n;

			}



		} else if (header->bDescriptorType ==

				USB_DT_INTERFACE_ASSOCIATION) {

			if (iad_num == USB_MAXIADS) {

				dev_warn(ddev, "found more Interface "

					       "Association Descriptors "

					       "than allocated for in "

					       "configuration %d\n", cfgno);

			} else {

				config->intf_assoc[iad_num] =

					(struct usb_interface_assoc_descriptor

					*)header;

				iad_num++;

			}



		} else if (header->bDescriptorType == USB_DT_DEVICE ||

			    header->bDescriptorType == USB_DT_CONFIG)

			dev_warn(ddev, "config %d contains an unexpected "

drivers/usb/core/devices.c

+26 −0
Original line number Diff line number Diff line
@@ -102,6 +102,10 @@ static const char *format_config = 
/* C:  #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */

  "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";

  

static const char *format_iad =

/* A:  FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */

  "A:  FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n";



static const char *format_iface =

/* I:  If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/

  "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
@@ -146,6 +150,7 @@ static const struct class_info clas_info[] = 
	{USB_CLASS_STILL_IMAGE,		"still"},

	{USB_CLASS_CSCID,		"scard"},

	{USB_CLASS_CONTENT_SEC,		"c-sec"},

	{USB_CLASS_VIDEO,		"video"},

	{-1,				"unk."}		/* leave as last */

};
@@ -286,6 +291,21 @@ static char *usb_dump_interface( 
	return start;

}



static char *usb_dump_iad_descriptor(char *start, char *end,

	const struct usb_interface_assoc_descriptor *iad)

{

	if (start > end)

		return start;

	start += sprintf(start, format_iad,

			 iad->bFirstInterface,

			 iad->bInterfaceCount,

			 iad->bFunctionClass,

			 class_decode(iad->bFunctionClass),

			 iad->bFunctionSubClass,

			 iad->bFunctionProtocol);

	return start;

}



/* TBD:

 * 0. TBDs

 * 1. marking active interface altsettings (code lists all, but should mark
@@ -322,6 +342,12 @@ static char *usb_dump_config ( 
	if (!config)		/* getting these some in 2.3.7; none in 2.3.6 */

		return start + sprintf(start, "(null Cfg. desc.)\n");

	start = usb_dump_config_descriptor(start, end, &config->desc, active);

	for (i = 0; i < USB_MAXIADS; i++) {

		if (config->intf_assoc[i] == NULL)

			break;

		start = usb_dump_iad_descriptor(start, end,

					config->intf_assoc[i]);

	}

	for (i = 0; i < config->desc.bNumInterfaces; i++) {

		intfc = config->intf_cache[i];

		interface = config->interface[i];

drivers/usb/core/message.c

+31 −0
Original line number Diff line number Diff line
@@ -1384,6 +1384,36 @@ struct device_type usb_if_device_type = { 
	.uevent =	usb_if_uevent,

};



static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,

						       struct usb_host_config *config,

						       u8 inum)

{

	struct usb_interface_assoc_descriptor *retval = NULL;

	struct usb_interface_assoc_descriptor *intf_assoc;

	int first_intf;

	int last_intf;

	int i;



	for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {

		intf_assoc = config->intf_assoc[i];

		if (intf_assoc->bInterfaceCount == 0)

			continue;



		first_intf = intf_assoc->bFirstInterface;

		last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);

		if (inum >= first_intf && inum <= last_intf) {

			if (!retval)

				retval = intf_assoc;

			else

				dev_err(&dev->dev, "Interface #%d referenced"

					" by multiple IADs\n", inum);

		}

	}



	return retval;

}





/*

 * usb_set_configuration - Makes a particular device setting be current

 * @dev: the device whose configuration is being updated
@@ -1530,6 +1560,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration) 
		intfc = cp->intf_cache[i];

		intf->altsetting = intfc->altsetting;

		intf->num_altsetting = intfc->num_altsetting;

		intf->intf_assoc = find_iad(dev, cp, i);

		kref_get(&intfc->ref);



		alt = usb_altnum_to_altsetting(intf, 0);

drivers/usb/core/sysfs.c

+34 −0
Original line number Diff line number Diff line
@@ -495,6 +495,25 @@ void usb_remove_sysfs_dev_files(struct usb_device *udev) 
	sysfs_remove_group(&dev->kobj, &dev_attr_grp);

}



/* Interface Accociation Descriptor fields */

#define usb_intf_assoc_attr(field, format_string)			\

static ssize_t								\

show_iad_##field (struct device *dev, struct device_attribute *attr,	\

		char *buf)						\

{									\

	struct usb_interface *intf = to_usb_interface (dev);		\

									\

	return sprintf (buf, format_string,				\

			intf->intf_assoc->field); 		\

}									\

static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);



usb_intf_assoc_attr (bFirstInterface, "%02x\n")

usb_intf_assoc_attr (bInterfaceCount, "%02d\n")

usb_intf_assoc_attr (bFunctionClass, "%02x\n")

usb_intf_assoc_attr (bFunctionSubClass, "%02x\n")

usb_intf_assoc_attr (bFunctionProtocol, "%02x\n")



/* Interface fields */

#define usb_intf_attr(field, format_string)				\

static ssize_t								\
@@ -558,6 +577,18 @@ static ssize_t show_modalias(struct device *dev, 
}

static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);



static struct attribute *intf_assoc_attrs[] = {

	&dev_attr_iad_bFirstInterface.attr,

	&dev_attr_iad_bInterfaceCount.attr,

	&dev_attr_iad_bFunctionClass.attr,

	&dev_attr_iad_bFunctionSubClass.attr,

	&dev_attr_iad_bFunctionProtocol.attr,

	NULL,

};

static struct attribute_group intf_assoc_attr_grp = {

	.attrs = intf_assoc_attrs,

};



static struct attribute *intf_attrs[] = {

	&dev_attr_bInterfaceNumber.attr,

	&dev_attr_bAlternateSetting.attr,
@@ -609,6 +640,8 @@ int usb_create_sysfs_intf_files(struct usb_interface *intf) 
		alt->string = usb_cache_string(udev, alt->desc.iInterface);

	if (alt->string)

		retval = device_create_file(dev, &dev_attr_interface);

	if (intf->intf_assoc)

		retval = sysfs_create_group(&dev->kobj, &intf_assoc_attr_grp);

	usb_create_intf_ep_files(intf, udev);

	return 0;

}
@@ -620,4 +653,5 @@ void usb_remove_sysfs_intf_files(struct usb_interface *intf) 
	usb_remove_intf_ep_files(intf);

	device_remove_file(dev, &dev_attr_interface);

	sysfs_remove_group(&dev->kobj, &intf_attr_grp);

	sysfs_remove_group(&intf->dev.kobj, &intf_assoc_attr_grp);

}

include/linux/usb.h

+10 −0
Original line number Diff line number Diff line
@@ -146,6 +146,10 @@ struct usb_interface { 
					 * active alternate setting */

	unsigned num_altsetting;	/* number of alternate settings */



	/* If there is an interface association descriptor then it will list

	 * the associated interfaces */

	struct usb_interface_assoc_descriptor *intf_assoc;



	int minor;			/* minor number this interface is

					 * bound to */

	enum usb_interface_condition condition;		/* state of binding */
@@ -175,6 +179,7 @@ void usb_put_intf(struct usb_interface *intf); 


/* this maximum is arbitrary */

#define USB_MAXINTERFACES	32

#define USB_MAXIADS		USB_MAXINTERFACES/2



/**

 * struct usb_interface_cache - long-term representation of a device interface
@@ -245,6 +250,11 @@ struct usb_host_config { 
	struct usb_config_descriptor	desc;



	char *string;		/* iConfiguration string, if present */



	/* List of any Interface Association Descriptors in this

	 * configuration. */

	struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];



	/* the interfaces associated with this configuration,

	 * stored in no particular order */

	struct usb_interface *interface[USB_MAXINTERFACES];