[PATCH v2 43/48] usb: gadget: udc: add usb_gadget_ep_match_desc() function

Robert Baldyga r.baldyga at samsung.com
Tue Jul 14 09:39:31 UTC 2015


Add function matching endpoint with ep descriptor. This function checks if
hardware endponit can fulfill requirements requested in descriptor. This
function can be used by UDC drivers in match_ep() callback to avoid writing
lots of repetitive code.

Signed-off-by: Robert Baldyga <r.baldyga at samsung.com>
---
 drivers/usb/gadget/udc/udc-core.c | 69 +++++++++++++++++++++++++++++++++++++++
 include/linux/usb/gadget.h        |  8 +++++
 2 files changed, 77 insertions(+)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index d69c355..2dff8df 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -129,6 +129,75 @@ EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
 
 /* ------------------------------------------------------------------------- */
 
+int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
+		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
+		struct usb_ss_ep_comp_descriptor *ep_comp)
+{
+	u8              type;
+	u16             max;
+	int             num_req_streams = 0;
+
+	/* endpoint already claimed? */
+	if (ep->claimed)
+		return 0;
+
+	type = usb_endpoint_type(desc);
+	max = 0x7ff & usb_endpoint_maxp(desc);
+
+	if (usb_endpoint_dir_in(desc) && !ep->caps.dir_in)
+		return 0;
+	else if (!ep->caps.dir_out)
+		return 0;
+
+	if (max > ep->maxpacket_limit)
+		return 0;
+
+	/* "high bandwidth" works only at high speed */
+	if (!gadget_is_dualspeed(gadget) && usb_endpoint_maxp(desc) & (3<<11))
+		return 0;
+
+	switch (type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		/* only support ep0 for portable CONTROL traffic */
+		return 0;
+	case USB_ENDPOINT_XFER_ISOC:
+		if (!ep->caps.type_iso)
+			return 0;
+		/* ISO:  limit 1023 bytes full speed, 1024 high/super speed */
+		if (!gadget_is_dualspeed(gadget) && max > 1023)
+			return 0;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		if (!ep->caps.type_bulk)
+			return 0;
+		if (ep_comp && gadget_is_superspeed(gadget)) {
+			/* Get the number of required streams from the
+			 * EP companion descriptor and see if the EP
+			 * matches it
+			 */
+			num_req_streams = ep_comp->bmAttributes & 0x1f;
+			if (num_req_streams > ep->max_streams)
+				return 0;
+		}
+		break;
+	case USB_ENDPOINT_XFER_INT:
+		/* Bulk endpoints handle interrupt transfers,
+		 * except the toggle-quirky iso-synch kind
+		 */
+		if (!ep->caps.type_int && !ep->caps.type_bulk)
+			return 0;
+		/* INT:  limit 64 bytes full speed, 1024 high/super speed */
+		if (!gadget_is_dualspeed(gadget) && max > 64)
+			return 0;
+		break;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_ep_match_desc);
+
+/* ------------------------------------------------------------------------- */
+
 static void usb_gadget_state_work(struct work_struct *work)
 {
 	struct usb_gadget *gadget = work_to_gadget(work);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 0041bb9..77e2c1e 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -1079,6 +1079,14 @@ extern void usb_gadget_giveback_request(struct usb_ep *ep,
 
 /*-------------------------------------------------------------------------*/
 
+/* utility to check if endpoint caps match descriptor needs */
+
+extern int usb_gadget_ep_match_desc(struct usb_gadget *gadget,
+		struct usb_ep *ep, struct usb_endpoint_descriptor *desc,
+		struct usb_ss_ep_comp_descriptor *ep_comp);
+
+/*-------------------------------------------------------------------------*/
+
 /* utility to update vbus status for udc core, it may be scheduled */
 extern void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status);
 
-- 
1.9.1



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