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: Craig W. Nadler <craig@nadler.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 5e113db..cb69aa1 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -295,6 +295,7 @@
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 @@
++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 "
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 6753ca0..87c794d6 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -102,6 +102,10 @@
/* 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 @@
{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 @@
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 @@
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];
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 4c14323..530e854 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1384,6 +1384,36 @@
.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 @@
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);
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 5dfe31b..d47ae89 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -495,6 +495,25 @@
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 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 @@
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 @@
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);
}
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 533c323..7a60946 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -146,6 +146,10 @@
* 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 @@
/* 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_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];