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@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 85 +++++++++++++++++++++++++++++++++++++++
drivers/usb/gadget/epautoconf.c | 1 +
include/linux/usb/composite.h | 3 +
include/linux/usb/gadget.h | 3 +
4 files changed, 92 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 5cbb1a4..1c6bd66 100644
--- 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 9b7360f..0022d44 100644
--- 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 b78cba4..2014d6b 100644
--- 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 5c4c30c..8015ceb 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -132,6 +132,8 @@ 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.
*
@@ -146,6 +148,7 @@ 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;
};
--
1.7.3.3
--
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