usb: gadget: add streams support to the gadget framework

This patch defines necessary fields to support
streaming for USB3.0.

It implements a new function, called
usb_ep_autoconfig_ss(), to be used instead of the
existing usb_ep_autoconfig() when working in
SuperSpeed mode and there is a need to search for
an endpoint according to the number of required
streams.

[ balbi@ti.com : slight changes to commit log ]

Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 100 insertions, 25 deletions

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 0022d44060ae..91c032fbdf1c 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -63,13 +63,16 @@ static int
 ep_matches (
         struct usb_gadget               *gadget,
         struct usb_ep                   *ep,
-        struct usb_endpoint_descriptor  *desc
+        struct usb_endpoint_descriptor  *desc,
+        struct usb_ss_ep_comp_descriptor *ep_comp
 )
 {
         u8              type;
         const char      *tmp;
         u16             max;
 
+        int             num_req_streams = 0;
+
         /* endpoint already claimed? */
         if (NULL != ep->driver_data)
                 return 0;
@@ -129,6 +132,22 @@ ep_matches (
         }
 
         /*
+         * Get the number of required streams from the EP companion
+         * descriptor and see if the EP matches it
+         */
+        if (usb_endpoint_xfer_bulk(desc)) {
+                if (ep_comp) {
+                        num_req_streams = ep_comp->bmAttributes & 0x1f;
+                        if (num_req_streams > ep->max_streams)
+                                return 0;
+                        /* Update the ep_comp descriptor if needed */
+                        if (num_req_streams != ep->max_streams)
+                                ep_comp->bmAttributes = ep->max_streams;
+                }
+
+        }
+
+        /*
          * If the protocol driver hasn't yet decided on wMaxPacketSize
          * and wants to know the maximum possible, provide the info.
          */
@@ -208,38 +227,53 @@ find_ep (struct usb_gadget *gadget, const char *name)
 }
 
 /**
- * usb_ep_autoconfig - choose an endpoint matching the descriptor
+ * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
+ * descriptor and ep companion descriptor
  * @gadget: The device to which the endpoint must belong.
  * @desc: Endpoint descriptor, with endpoint direction and transfer mode
- *      initialized.  For periodic transfers, the maximum packet
- *      size must also be initialized.  This is modified on success.
+ *    initialized.  For periodic transfers, the maximum packet
+ *    size must also be initialized.  This is modified on
+ *    success.
+ * @ep_comp: Endpoint companion descriptor, with the required
+ *    number of streams. Will be modified when the chosen EP
+ *    supports a different number of streams.
  *
- * By choosing an endpoint to use with the specified descriptor, this
- * routine simplifies writing gadget drivers that work with multiple
- * USB device controllers.  The endpoint would be passed later to
- * usb_ep_enable(), along with some descriptor.
+ * This routine replaces the usb_ep_autoconfig when needed
+ * superspeed enhancments. If such enhancemnets are required,
+ * the FD should call usb_ep_autoconfig_ss directly and provide
+ * the additional ep_comp parameter.
+ *
+ * By choosing an endpoint to use with the specified descriptor,
+ * this routine simplifies writing gadget drivers that work with
+ * multiple USB device controllers.  The endpoint would be
+ * passed later to usb_ep_enable(), along with some descriptor.
  *
  * That second descriptor won't always be the same as the first one.
  * For example, isochronous endpoints can be autoconfigured for high
  * bandwidth, and then used in several lower bandwidth altsettings.
  * Also, high and full speed descriptors will be different.
  *
- * Be sure to examine and test the results of autoconfiguration on your
- * hardware.  This code may not make the best choices about how to use the
- * USB controller, and it can't know all the restrictions that may apply.
- * Some combinations of driver and hardware won't be able to autoconfigure.
+ * Be sure to examine and test the results of autoconfiguration
+ * on your hardware.  This code may not make the best choices
+ * about how to use the USB controller, and it can't know all
+ * the restrictions that may apply. Some combinations of driver
+ * and hardware won't be able to autoconfigure.
  *
  * On success, this returns an un-claimed usb_ep, and modifies the endpoint
  * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
- * is initialized as if the endpoint were used at full speed.  To prevent
- * the endpoint from being returned by a later autoconfig call, claim it
- * by assigning ep->driver_data to some non-null value.
+ * is initialized as if the endpoint were used at full speed and
+ * the bmAttribute field in the ep companion descriptor is
+ * updated with the assigned number of streams if it is
+ * different from the original value. To prevent the endpoint
+ * from being returned by a later autoconfig call, claim it by
+ * assigning ep->driver_data to some non-null value.
  *
  * On failure, this returns a null endpoint descriptor.
  */
-struct usb_ep *usb_ep_autoconfig (
+struct usb_ep *usb_ep_autoconfig_ss(
         struct usb_gadget               *gadget,
-        struct usb_endpoint_descriptor  *desc
+        struct usb_endpoint_descriptor  *desc,
+        struct usb_ss_ep_comp_descriptor *ep_comp
 )
 {
         struct usb_ep   *ep;
@@ -253,23 +287,24 @@ struct usb_ep *usb_ep_autoconfig (
         if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
                 /* ep-e, ep-f are PIO with only 64 byte fifos */
                 ep = find_ep (gadget, "ep-e");
-                if (ep && ep_matches (gadget, ep, desc))
+                if (ep && ep_matches(gadget, ep, desc, ep_comp))
                         return ep;
                 ep = find_ep (gadget, "ep-f");
-                if (ep && ep_matches (gadget, ep, desc))
+                if (ep && ep_matches(gadget, ep, desc, ep_comp))
                         return ep;
 
         } else if (gadget_is_goku (gadget)) {
                 if (USB_ENDPOINT_XFER_INT == type) {
                         /* single buffering is enough */
-                        ep = find_ep (gadget, "ep3-bulk");
-                        if (ep && ep_matches (gadget, ep, desc))
+                        ep = find_ep(gadget, "ep3-bulk");
+                        if (ep && ep_matches(gadget, ep, desc, ep_comp))
                                 return ep;
                 } else if (USB_ENDPOINT_XFER_BULK == type
                                 && (USB_DIR_IN & desc->bEndpointAddress)) {
                         /* DMA may be available */
-                        ep = find_ep (gadget, "ep2-bulk");
-                        if (ep && ep_matches (gadget, ep, desc))
+                        ep = find_ep(gadget, "ep2-bulk");
+                        if (ep && ep_matches(gadget, ep, desc,
+                                              ep_comp))
                                 return ep;
                 }
 
@@ -288,14 +323,14 @@ struct usb_ep *usb_ep_autoconfig (
                                 ep = find_ep(gadget, "ep2out");
                 } else
                         ep = NULL;
-                if (ep && ep_matches (gadget, ep, desc))
+                if (ep && ep_matches(gadget, ep, desc, ep_comp))
                         return ep;
 #endif
         }
 
         /* Second, look at endpoints until an unclaimed one looks usable */
         list_for_each_entry (ep, &gadget->ep_list, ep_list) {
-                if (ep_matches (gadget, ep, desc))
+                if (ep_matches(gadget, ep, desc, ep_comp))
                         return ep;
         }
 
@@ -304,6 +339,46 @@ struct usb_ep *usb_ep_autoconfig (
 }
 
 /**
+ * usb_ep_autoconfig() - choose an endpoint matching the
+ * descriptor
+ * @gadget: The device to which the endpoint must belong.
+ * @desc: Endpoint descriptor, with endpoint direction and transfer mode
+ *      initialized.  For periodic transfers, the maximum packet
+ *      size must also be initialized.  This is modified on success.
+ *
+ * By choosing an endpoint to use with the specified descriptor, this
+ * routine simplifies writing gadget drivers that work with multiple
+ * USB device controllers.  The endpoint would be passed later to
+ * usb_ep_enable(), along with some descriptor.
+ *
+ * That second descriptor won't always be the same as the first one.
+ * For example, isochronous endpoints can be autoconfigured for high
+ * bandwidth, and then used in several lower bandwidth altsettings.
+ * Also, high and full speed descriptors will be different.
+ *
+ * Be sure to examine and test the results of autoconfiguration on your
+ * hardware.  This code may not make the best choices about how to use the
+ * USB controller, and it can't know all the restrictions that may apply.
+ * Some combinations of driver and hardware won't be able to autoconfigure.
+ *
+ * On success, this returns an un-claimed usb_ep, and modifies the endpoint
+ * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
+ * is initialized as if the endpoint were used at full speed.  To prevent
+ * the endpoint from being returned by a later autoconfig call, claim it
+ * by assigning ep->driver_data to some non-null value.
+ *
+ * On failure, this returns a null endpoint descriptor.
+ */
+struct usb_ep *usb_ep_autoconfig(
+        struct usb_gadget               *gadget,
+        struct usb_endpoint_descriptor  *desc
+)
+{
+        return usb_ep_autoconfig_ss(gadget, desc, NULL);
+}
+
+
+/**
  * usb_ep_autoconfig_reset - reset endpoint autoconfig state
  * @gadget: device for which autoconfig state will be reset
  *