usb: add support for "grouped" interfaces and the Interface Association Descriptor

This is used for some devices that have multiple interfaces that form a logic
device. An example is Video Class, which has a Control interface and a
Streaming interface. There can be additional interfaces on the same (physical)
devices (e.g. a microphone), and Interface Association Descriptor handles this
case.

Signed-off-by: Brad Hards <bradh@frogmouth.net>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Brad Hards 2011-04-03 15:33:21 +10:00 committed by Gerd Hoffmann
parent fef13fa8e4
commit 6e625fc704
3 changed files with 68 additions and 0 deletions

View File

@ -91,6 +91,18 @@ int usb_desc_config(const USBDescConfig *conf, uint8_t *dest, size_t len)
dest[0x08] = conf->bMaxPower;
wTotalLength += bLength;
/* handle grouped interfaces if any*/
for (i = 0; i < conf->nif_groups; i++) {
rc = usb_desc_iface_group(&(conf->if_groups[i]),
dest + wTotalLength,
len - wTotalLength);
if (rc < 0) {
return rc;
}
wTotalLength += rc;
}
/* handle normal (ungrouped / no IAD) interfaces if any */
for (i = 0; i < conf->nif; i++) {
rc = usb_desc_iface(conf->ifs + i, dest + wTotalLength, len - wTotalLength);
if (rc < 0) {
@ -104,6 +116,41 @@ int usb_desc_config(const USBDescConfig *conf, uint8_t *dest, size_t len)
return wTotalLength;
}
int usb_desc_iface_group(const USBDescIfaceAssoc *iad, uint8_t *dest,
size_t len)
{
int pos = 0;
int i = 0;
/* handle interface association descriptor */
uint8_t bLength = 0x08;
if (len < bLength) {
return -1;
}
dest[0x00] = bLength;
dest[0x01] = USB_DT_INTERFACE_ASSOC;
dest[0x02] = iad->bFirstInterface;
dest[0x03] = iad->bInterfaceCount;
dest[0x04] = iad->bFunctionClass;
dest[0x05] = iad->bFunctionSubClass;
dest[0x06] = iad->bFunctionProtocol;
dest[0x07] = iad->iFunction;
pos += bLength;
/* handle associated interfaces in this group */
for (i = 0; i < iad->nif; i++) {
int rc = usb_desc_iface(&(iad->ifs[i]), dest + pos, len - pos);
if (rc < 0) {
return rc;
}
pos += rc;
}
return pos;
}
int usb_desc_iface(const USBDescIface *iface, uint8_t *dest, size_t len)
{
uint8_t bLength = 0x09;

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@ -30,6 +30,24 @@ struct USBDescConfig {
uint8_t bmAttributes;
uint8_t bMaxPower;
/* grouped interfaces */
uint8_t nif_groups;
const USBDescIfaceAssoc *if_groups;
/* "normal" interfaces */
uint8_t nif;
const USBDescIface *ifs;
};
/* conceptually an Interface Association Descriptor, and releated interfaces */
struct USBDescIfaceAssoc {
uint8_t bFirstInterface;
uint8_t bInterfaceCount;
uint8_t bFunctionClass;
uint8_t bFunctionSubClass;
uint8_t bFunctionProtocol;
uint8_t iFunction;
uint8_t nif;
const USBDescIface *ifs;
};
@ -75,6 +93,8 @@ int usb_desc_device(const USBDescID *id, const USBDescDevice *dev,
int usb_desc_device_qualifier(const USBDescDevice *dev,
uint8_t *dest, size_t len);
int usb_desc_config(const USBDescConfig *conf, uint8_t *dest, size_t len);
int usb_desc_iface_group(const USBDescIfaceAssoc *iad, uint8_t *dest,
size_t len);
int usb_desc_iface(const USBDescIface *iface, uint8_t *dest, size_t len);
int usb_desc_endpoint(const USBDescEndpoint *ep, uint8_t *dest, size_t len);
int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len);

View File

@ -141,6 +141,7 @@ typedef struct USBDesc USBDesc;
typedef struct USBDescID USBDescID;
typedef struct USBDescDevice USBDescDevice;
typedef struct USBDescConfig USBDescConfig;
typedef struct USBDescIfaceAssoc USBDescIfaceAssoc;
typedef struct USBDescIface USBDescIface;
typedef struct USBDescEndpoint USBDescEndpoint;
typedef struct USBDescOther USBDescOther;