usb: chipidea: udc: configure iso endpoints

This patch adds iso endpoint support to the device controller.
It makes use of the multiplication bits in the maxpacket field
of the endpoint and calculates the multiplier bits for each
transfer description on every request.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/core.c

@@ -43,7 +43,7 @@
  *
  * TODO List
  * - OTG
- * - Isochronous & Interrupt Traffic
+ * - Interrupt Traffic
  * - Handle requests which spawns into several TDs
  * - GET_STATUS(device) - always reports 0
  * - Gadget API (majority of optional features)

drivers/usb/chipidea/udc.c

@@ -466,6 +466,14 @@ static int _hardware_enqueue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 	mEp->qh.ptr->td.token &=
 		cpu_to_le32(~(TD_STATUS_HALTED|TD_STATUS_ACTIVE));
 
+	if (mEp->type == USB_ENDPOINT_XFER_ISOC) {
+		u32 mul = mReq->req.length / mEp->ep.maxpacket;
+
+		if (mReq->req.length % mEp->ep.maxpacket)
+			mul++;
+		mEp->qh.ptr->cap |= mul << __ffs(QH_MULT);
+	}
+
 	wmb();   /* synchronize before ep prime */
 
 	ret = hw_ep_prime(ci, mEp->num, mEp->dir,
@@ -678,6 +686,12 @@ static int _ep_queue(struct usb_ep *ep, struct usb_request *req,
 		}
 	}
 
+	if (usb_endpoint_xfer_isoc(mEp->ep.desc) &&
+	    mReq->req.length > (1 + mEp->ep.mult) * mEp->ep.maxpacket) {
+		dev_err(mEp->ci->dev, "request length too big for isochronous\n");
+		return -EMSGSIZE;
+	}
+
 	/* first nuke then test link, e.g. previous status has not sent */
 	if (!list_empty(&mReq->queue)) {
 		dev_err(mEp->ci->dev, "request already in queue\n");
@@ -1060,7 +1074,8 @@ static int ep_enable(struct usb_ep *ep,
 	mEp->num  = usb_endpoint_num(desc);
 	mEp->type = usb_endpoint_type(desc);
 
-	mEp->ep.maxpacket = usb_endpoint_maxp(desc);
+	mEp->ep.maxpacket = usb_endpoint_maxp(desc) & 0x07ff;
+	mEp->ep.mult = QH_ISO_MULT(usb_endpoint_maxp(desc));
 
 	if (mEp->type == USB_ENDPOINT_XFER_CONTROL)
 		cap |= QH_IOS;
@@ -1246,6 +1261,9 @@ static int ep_set_halt(struct usb_ep *ep, int value)
 	if (ep == NULL || mEp->ep.desc == NULL)
 		return -EINVAL;
 
+	if (usb_endpoint_xfer_isoc(mEp->ep.desc))
+		return -EOPNOTSUPP;
+
 	spin_lock_irqsave(mEp->lock, flags);
 
 #ifndef STALL_IN

drivers/usb/chipidea/udc.h

@@ -50,6 +50,7 @@ struct ci13xxx_qh {
 #define QH_MAX_PKT            (0x07FFUL << 16)
 #define QH_ZLT                BIT(29)
 #define QH_MULT               (0x0003UL << 30)
+#define QH_ISO_MULT(x)		((x >> 11) & 0x03)
 	/* 1 */
 	u32 curr;
 	/* 2 - 8 */