usb: Add USB 3.1 SuperSpeedPlus device capability descriptor

USB 3.1 SuperSpeedPlus device capability descriptor is returned as part
of the bos descriptor for devices that support SuperSpeedPlus protocol.

The descriptor contains more detailed information about the supported
speeds of the device. More details about the descriptor can be found in
the USB 3.1 specification section 9.6.2.5
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

include/uapi/linux/usb/ch9.h

@@ -866,6 +866,35 @@ struct usb_ss_container_id_descriptor {
 } __attribute__((packed));
 
 #define USB_DT_USB_SS_CONTN_ID_SIZE	20
+
+/*
+ * SuperSpeed Plus USB Capability descriptor: Defines the set of
+ * SuperSpeed Plus USB specific device level capabilities
+ */
+#define	USB_SSP_CAP_TYPE	0xa
+struct usb_ssp_cap_descriptor {
+	__u8  bLength;
+	__u8  bDescriptorType;
+	__u8  bDevCapabilityType;
+	__u8  bReserved;
+	__le32 bmAttributes;
+#define USB_SSP_SUBLINK_SPEED_ATTRIBS	(0x1f << 0) /* sublink speed entries */
+#define USB_SSP_SUBLINK_SPEED_IDS	(0xf << 5)  /* speed ID entries */
+	__u16  wFunctionalitySupport;
+#define USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID	(0xf)
+#define USB_SSP_MIN_RX_LANE_COUNT		(0xf << 8)
+#define USB_SSP_MIN_TX_LANE_COUNT		(0xf << 12)
+	__le16 wReserved;
+	__le32 bmSublinkSpeedAttr[1]; /* list of sublink speed attrib entries */
+#define USB_SSP_SUBLINK_SPEED_SSID	(0xf)		/* sublink speed ID */
+#define USB_SSP_SUBLINK_SPEED_LSE	(0x3 << 4)	/* Lanespeed exponent */
+#define USB_SSP_SUBLINK_SPEED_ST	(0x3 << 6)	/* Sublink type */
+#define USB_SSP_SUBLINK_SPEED_RSVD	(0x3f << 8)	/* Reserved */
+#define USB_SSP_SUBLINK_SPEED_LP	(0x3 << 14)	/* Link protocol */
+#define USB_SSP_SUBLINK_SPEED_LSM	(0xff << 16)	/* Lanespeed mantissa */
+} __attribute__((packed));
+
+
 /*-------------------------------------------------------------------------*/
 
 /* USB_DT_WIRELESS_ENDPOINT_COMP:  companion descriptor associated with