[24/24] xhci: Add host support for eUSB2 double isochronous bandwidth devices

diff --git a/drivers/usb/host/xhci-caps.h b/drivers/usb/host/xhci-caps.h
index 4b8ff4815644..723a56052439 100644
--- a/drivers/usb/host/xhci-caps.h
+++ b/drivers/usb/host/xhci-caps.h
@@ -89,3 +89,5 @@ 
 #define HCC2_GSC(p)             ((p) & (1 << 8))
 /* true: HC support Virtualization Based Trusted I/O Capability */
 #define HCC2_VTC(p)             ((p) & (1 << 9))
+/* true: HC support Double BW on a eUSB2 HS ISOC EP */
+#define HCC2_EUSB2_DIC(p)	((p) & (1 << 11))
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index bd745a0f2f78..494f9eacab84 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1328,18 +1328,36 @@  static unsigned int xhci_get_endpoint_interval(struct usb_device *udev,
 	return interval;
 }
 
-/* The "Mult" field in the endpoint context is only set for SuperSpeed isoc eps.
+/*
+ * xHCs without LEC use the "Mult" field in the endpoint context for SuperSpeed
+ * isoc eps, and High speed isoc eps that support bandwidth doubling. Standard
  * High speed endpoint descriptors can define "the number of additional
  * transaction opportunities per microframe", but that goes in the Max Burst
  * endpoint context field.
  */
-static u32 xhci_get_endpoint_mult(struct usb_device *udev,
-		struct usb_host_endpoint *ep)
+static u32 xhci_get_endpoint_mult(struct xhci_hcd *xhci,
+				  struct usb_device *udev,
+				  struct usb_host_endpoint *ep)
 {
-	if (udev->speed < USB_SPEED_SUPER ||
-			!usb_endpoint_xfer_isoc(&ep->desc))
+	bool lec;
+
+	/* xhci 1.1 with LEC set does not use mult field, except intel eusb2 */
+	lec = xhci->hci_version > 0x100 && HCC2_LEC(xhci->hcc_params2);
+
+	/* eusb2 double isoc bw devices are the only usb2 devices using mult */
+	if (xhci_eusb2_is_isoc_bw_double(udev, ep)) {
+		if (!lec || xhci->quirks & XHCI_INTEL_HOST)
+			return 1;
+	}
+
+	/* Oherwise only isoc transfers on hosts without LEC uses mult field */
+	if (!usb_endpoint_xfer_isoc(&ep->desc) || lec)
 		return 0;
-	return ep->ss_ep_comp.bmAttributes;
+
+	if (udev->speed >= USB_SPEED_SUPER)
+		return ep->ss_ep_comp.bmAttributes;
+
+	return 0;
 }
 
 static u32 xhci_get_endpoint_max_burst(struct usb_device *udev,
@@ -1351,8 +1369,18 @@  static u32 xhci_get_endpoint_max_burst(struct usb_device *udev,
 
 	if (udev->speed == USB_SPEED_HIGH &&
 	    (usb_endpoint_xfer_isoc(&ep->desc) ||
-	     usb_endpoint_xfer_int(&ep->desc)))
-		return usb_endpoint_maxp_mult(&ep->desc) - 1;
+	     usb_endpoint_xfer_int(&ep->desc))) {
+		if (xhci_eusb2_is_isoc_bw_double(udev, ep))
+			/*
+			 * eUSB2 double isoc bw endpoints max packet field
+			 * service opportunity bits 12:11 are not valid, so set
+			 * the ctx burst to max service opportunity "2" as these
+			 * eps support transferring over 3072 bytes per interval
+			 */
+			return 2;
+		else
+			return usb_endpoint_maxp_mult(&ep->desc) - 1;
+	}
 
 	return 0;
 }
@@ -1400,6 +1428,10 @@  static u32 xhci_get_max_esit_payload(struct usb_device *udev,
 	if (udev->speed >= USB_SPEED_SUPER)
 		return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);
 
+	/* High speed eusb2 double isoc bw with over 3072 bytes per esit */
+	if (xhci_eusb2_is_isoc_bw_double(udev, ep))
+		return le32_to_cpu(ep->eusb2_isoc_ep_comp.dwBytesPerInterval);
+
 	max_packet = usb_endpoint_maxp(&ep->desc);
 	max_burst = usb_endpoint_maxp_mult(&ep->desc);
 	/* A 0 in max burst means 1 transfer per ESIT */
@@ -1437,6 +1469,13 @@  int xhci_endpoint_init(struct xhci_hcd *xhci,
 
 	ring_type = usb_endpoint_type(&ep->desc);
 
+	/* Ensure host supports double isoc bandwidth for eusb2 devices */
+	if (xhci_eusb2_is_isoc_bw_double(udev, ep) &&
+	    !HCC2_EUSB2_DIC(xhci->hcc_params2))	{
+		dev_dbg(&udev->dev, "Double Isoc Bandwidth not supported by xhci\n");
+		return -EINVAL;
+	}
+
 	/*
 	 * Get values to fill the endpoint context, mostly from ep descriptor.
 	 * The average TRB buffer lengt for bulk endpoints is unclear as we
@@ -1456,8 +1495,8 @@  int xhci_endpoint_init(struct xhci_hcd *xhci,
 		}
 	}
 
-	mult = xhci_get_endpoint_mult(udev, ep);
-	max_packet = usb_endpoint_maxp(&ep->desc);
+	mult = xhci_get_endpoint_mult(xhci, udev, ep);
+	max_packet = xhci_usb_endpoint_maxp(udev, ep);
 	max_burst = xhci_get_endpoint_max_burst(udev, ep);
 	avg_trb_len = max_esit_payload;
 
@@ -1478,9 +1517,6 @@  int xhci_endpoint_init(struct xhci_hcd *xhci,
 	/* xHCI 1.0 and 1.1 indicates that ctrl ep avg TRB Length should be 8 */
 	if (usb_endpoint_xfer_control(&ep->desc) && xhci->hci_version >= 0x100)
 		avg_trb_len = 8;
-	/* xhci 1.1 with LEC support doesn't use mult field, use RsvdZ */
-	if ((xhci->hci_version > 0x100) && HCC2_LEC(xhci->hcc_params2))
-		mult = 0;
 
 	/* Set up the endpoint ring */
 	virt_dev->eps[ep_index].new_ring =
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index eff6b84dc915..f94626d8bcce 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3549,7 +3549,7 @@  static u32 xhci_td_remainder(struct xhci_hcd *xhci, int transferred,
 	if ((xhci->quirks & XHCI_MTK_HOST) && (xhci->hci_version < 0x100))
 		trb_buff_len = 0;
 
-	maxp = usb_endpoint_maxp(&urb->ep->desc);
+	maxp = xhci_usb_endpoint_maxp(urb->dev, urb->ep);
 	total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
 
 	/* Queueing functions don't count the current TRB into transferred */
@@ -3566,7 +3566,7 @@  static int xhci_align_td(struct xhci_hcd *xhci, struct urb *urb, u32 enqd_len,
 	u32 new_buff_len;
 	size_t len;
 
-	max_pkt = usb_endpoint_maxp(&urb->ep->desc);
+	max_pkt = xhci_usb_endpoint_maxp(urb->dev, urb->ep);
 	unalign = (enqd_len + *trb_buff_len) % max_pkt;
 
 	/* we got lucky, last normal TRB data on segment is packet aligned */
@@ -4137,7 +4137,7 @@  static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		addr = start_addr + urb->iso_frame_desc[i].offset;
 		td_len = urb->iso_frame_desc[i].length;
 		td_remain_len = td_len;
-		max_pkt = usb_endpoint_maxp(&urb->ep->desc);
+		max_pkt = xhci_usb_endpoint_maxp(urb->dev, urb->ep);
 		total_pkt_count = DIV_ROUND_UP(td_len, max_pkt);
 
 		/* A zero-length transfer still involves at least one packet. */
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 9769c68b2e9f..2ac383929b1c 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1353,7 +1353,7 @@  static bool xhci_urb_temp_buffer_required(struct usb_hcd *hcd,
 	struct scatterlist *tail_sg;
 
 	tail_sg = urb->sg;
-	max_pkt = usb_endpoint_maxp(&urb->ep->desc);
+	max_pkt = xhci_usb_endpoint_maxp(urb->dev, urb->ep);
 
 	if (!urb->num_sgs)
 		return ret;
@@ -2940,6 +2940,21 @@  int xhci_stop_endpoint_sync(struct xhci_hcd *xhci, struct xhci_virt_ep *ep, int
 }
 EXPORT_SYMBOL_GPL(xhci_stop_endpoint_sync);
 
+/*
+ * xhci_usb_endpoint_maxp - get endpoint max packet size
+ * @host_ep: USB host endpoint to be checked
+ *
+ * Returns max packet from the correct descriptor
+ */
+
+int xhci_usb_endpoint_maxp(struct usb_device *udev,
+			   struct usb_host_endpoint *host_ep)
+{
+	if (xhci_eusb2_is_isoc_bw_double(udev, host_ep))
+		return le16_to_cpu(host_ep->eusb2_isoc_ep_comp.wMaxPacketSize);
+	return usb_endpoint_maxp(&host_ep->desc);
+}
+
 /* Issue a configure endpoint command or evaluate context command
  * and wait for it to finish.
  */
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 49887a303e43..e0c5238c9327 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1735,6 +1735,23 @@  static inline bool xhci_has_one_roothub(struct xhci_hcd *xhci)
 	       (!xhci->usb2_rhub.num_ports || !xhci->usb3_rhub.num_ports);
 }
 
+/*
+ * USB 2.0 specification, chapter 5.6.4 Isochronous Transfer Bus Access
+ * Constraint. A high speed endpoint can move up to 3072 bytes per microframe
+ * (or 192Mb/s).
+ */
+#define MAX_ISOC_XFER_SIZE_HS  3072
+
+static inline bool xhci_eusb2_is_isoc_bw_double(struct usb_device *udev,
+						struct usb_host_endpoint *ep)
+{
+	return le16_to_cpu(udev->descriptor.bcdUSB) == 0x220 &&
+		usb_endpoint_xfer_isoc(&ep->desc) &&
+		le16_to_cpu(ep->desc.wMaxPacketSize) == 0 &&
+		le32_to_cpu(ep->eusb2_isoc_ep_comp.dwBytesPerInterval) >
+		MAX_ISOC_XFER_SIZE_HS;
+}
+
 #define xhci_dbg(xhci, fmt, args...) \
 	dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_err(xhci, fmt, args...) \
@@ -1958,6 +1975,8 @@  void xhci_update_erst_dequeue(struct xhci_hcd *xhci,
 			      struct xhci_interrupter *ir,
 			      bool clear_ehb);
 void xhci_add_interrupter(struct xhci_hcd *xhci, unsigned int intr_num);
+int xhci_usb_endpoint_maxp(struct usb_device *udev,
+			   struct usb_host_endpoint *host_ep);
 
 /* xHCI roothub code */
 void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port,