usb: gadget: configure endpoint according to gadget speed

Add config_ep_by_speed() to configure the endpoint
according to the gadget speed.

Using this function will spare the FDs from handling
the endpoint chosen descriptor.

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>

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 5cbb1a41c223d7cd0f139cd1dba4c6c2248f69f8..1c6bd666150a30e78e44e793a1845271e8322229 100644 (file)
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -74,6 +74,91 @@ MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
 static char composite_manufacturer[50];
 
 /*-------------------------------------------------------------------------*/
+/**
+ * next_ep_desc() - advance to the next EP descriptor
+ * @t: currect pointer within descriptor array
+ *
+ * Return: next EP descriptor or NULL
+ *
+ * Iterate over @t until either EP descriptor found or
+ * NULL (that indicates end of list) encountered
+ */
+static struct usb_descriptor_header**
+next_ep_desc(struct usb_descriptor_header **t)
+{
+       for (; *t; t++) {
+               if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
+                       return t;
+       }
+       return NULL;
+}
+
+/*
+ * for_each_ep_desc()- iterate over endpoint descriptors in the
+ *             descriptors list
+ * @start:     pointer within descriptor array.
+ * @ep_desc:   endpoint descriptor to use as the loop cursor
+ */
+#define for_each_ep_desc(start, ep_desc) \
+       for (ep_desc = next_ep_desc(start); \
+             ep_desc; ep_desc = next_ep_desc(ep_desc+1))
+
+/**
+ * config_ep_by_speed() - configures the given endpoint
+ * according to gadget speed.
+ * @g: pointer to the gadget
+ * @f: usb function
+ * @_ep: the endpoint to configure
+ *
+ * Return: error code, 0 on success
+ *
+ * This function chooses the right descriptors for a given
+ * endpoint according to gadget speed and saves it in the
+ * endpoint desc field. If the endpoint already has a descriptor
+ * assigned to it - overwrites it with currently corresponding
+ * descriptor. The endpoint maxpacket field is updated according
+ * to the chosen descriptor.
+ * Note: the supplied function should hold all the descriptors
+ * for supported speeds
+ */
+int config_ep_by_speed(struct usb_gadget *g,
+                       struct usb_function *f,
+                       struct usb_ep *_ep)
+{
+       struct usb_endpoint_descriptor *chosen_desc = NULL;
+       struct usb_descriptor_header **speed_desc = NULL;
+
+       struct usb_descriptor_header **d_spd; /* cursor for speed desc */
+
+       if (!g || !f || !_ep)
+               return -EIO;
+
+       /* select desired speed */
+       switch (g->speed) {
+       case USB_SPEED_HIGH:
+               if (gadget_is_dualspeed(g)) {
+                       speed_desc = f->hs_descriptors;
+                       break;
+               }
+               /* else: fall through */
+       default:
+               speed_desc = f->descriptors;
+       }
+       /* find descriptors */
+       for_each_ep_desc(speed_desc, d_spd) {
+               chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
+               if (chosen_desc->bEndpointAddress == _ep->address)
+                       goto ep_found;
+       }
+       return -EIO;
+
+ep_found:
+       /* commit results */
+       _ep->maxpacket = le16_to_cpu(chosen_desc->wMaxPacketSize);
+       _ep->desc = chosen_desc;
+
+       return 0;
+}
 
 /**
  * usb_add_function() - add a function to a configuration

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 9b7360ff5aa70c2992256cda8b1533fa76d7f4b9..0022d44060ae4a889c66eb380d7af456845d393b 100644 (file)
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -191,6 +191,7 @@ ep_matches (
                        size = 64;
                desc->wMaxPacketSize = cpu_to_le16(size);
        }
+       ep->address = desc->bEndpointAddress;
        return 1;
 }
 

diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index b78cba466d3dcc201755209939c70ce312056f4d..2014d6b1babc0f7251cafcd1d43f09e87ffb5471 100644 (file)
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -145,6 +145,9 @@ int usb_function_activate(struct usb_function *);
 
 int usb_interface_id(struct usb_configuration *, struct usb_function *);
 
+int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
+                       struct usb_ep *_ep);
+
 /**
  * ep_choose - select descriptor endpoint at current device speed
  * @g: gadget, connected and running at some speed

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index fe50912585f8251af455cd8d9cd86c808f1262d9..0bcc2b76bcd8067de85f81f2aaf35102b0c86542 100644 (file)
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -133,6 +133,8 @@ struct usb_ep_ops {
  *     value can sometimes be reduced (hardware allowing), according to
  *      the endpoint descriptor used to configure the endpoint.
  * @driver_data:for use by the gadget driver.
+ * @address: used to identify the endpoint when finding descriptor that
+ *     matches connection speed
  * @desc: endpoint descriptor.  This pointer is set before the endpoint is
  *     enabled and remains valid until the endpoint is disabled.
  *
@@ -147,6 +149,7 @@ struct usb_ep {
        const struct usb_ep_ops *ops;
        struct list_head        ep_list;
        unsigned                maxpacket:16;
+       u8                      address;
        const struct usb_endpoint_descriptor    *desc;
 };