usb: ch9: Add size macro for SSP dev cap descriptor
The SuperspeedPlus Device Capability Descriptor has a variable size
depending on the number of sublink speed attributes.
This patch adds a macro to calculate that size. The macro takes one
argument, the Sublink Speed Attribute Count (SSAC) as reported by the
descriptor in bmAttributes[4:0].
See USB 3.1 9.6.2.5, Table 9-19.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
index 252ac16..28bee8d 100644
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -923,6 +923,12 @@
__u8 bDevCapabilityType;
} __attribute__((packed));
+/*
+ * The size of the descriptor for the Sublink Speed Attribute Count
+ * (SSAC) specified in bmAttributes[4:0].
+ */
+#define USB_DT_USB_SSP_CAP_SIZE(ssac) (16 + ssac * 4)
+
/*-------------------------------------------------------------------------*/
/* USB_DT_WIRELESS_ENDPOINT_COMP: companion descriptor associated with