usb: Add USB3.1 SuperSpeedPlus Isoc Endpoint Companion descriptor

USB3.1 specifies a SuperSpeedPlus Isoc endpoint companion descriptor
which is returned as part of the devices complete configuration
descriptor.

It contains number of bytes per service interval which is needed when
reserving bus time in the schedule for transfers over 48K bytes per
service interval.

If bmAttributes bit 7 is set in the old SuperSpeed Endpoint Companion
descriptor, it will be ollowed by the new SuperSpeedPlus Isoc Endpoint
Companion descriptor.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/uapi/linux/usb/ch9.h

@@ -234,6 +234,8 @@ struct usb_ctrlrequest {
 #define USB_DT_PIPE_USAGE		0x24
 /* From the USB 3.0 spec */
 #define	USB_DT_SS_ENDPOINT_COMP		0x30
+/* From the USB 3.1 spec */
+#define	USB_DT_SSP_ISOC_ENDPOINT_COMP	0x31
 
 /* Conventional codes for class-specific descriptors.  The convention is
  * defined in the USB "Common Class" Spec (3.11).  Individual class specs
@@ -613,6 +615,20 @@ static inline int usb_endpoint_interrupt_type(
 
 /*-------------------------------------------------------------------------*/
 
+/* USB_DT_SSP_ISOC_ENDPOINT_COMP: SuperSpeedPlus Isochronous Endpoint Companion
+ * descriptor
+ */
+struct usb_ssp_isoc_ep_comp_descriptor {
+	__u8  bLength;
+	__u8  bDescriptorType;
+	__le16 wReseved;
+	__le32 dwBytesPerInterval;
+} __attribute__ ((packed));
+
+#define USB_DT_SSP_ISOC_EP_COMP_SIZE		8
+
+/*-------------------------------------------------------------------------*/
+
 /* USB_DT_SS_ENDPOINT_COMP: SuperSpeed Endpoint Companion descriptor */
 struct usb_ss_ep_comp_descriptor {
 	__u8  bLength;
@@ -646,6 +662,8 @@ usb_ss_max_streams(const struct usb_ss_ep_comp_descriptor *comp)
 
 /* Bits 1:0 of bmAttributes if this is an isoc endpoint */
 #define USB_SS_MULT(p)			(1 + ((p) & 0x3))
+/* Bit 7 of bmAttributes if a SSP isoc endpoint companion descriptor exists */
+#define USB_SS_SSP_ISOC_COMP(p)		((p) & (1 << 7))
 
 /*-------------------------------------------------------------------------*/