[PATCH v14 6/9] usb: Add streams support to the gadget framework

Tatyana Brokhman
2011-05-31T13:19:30Z

This patch defines necessary fields to support streaming for USB3.0.
It implements a new function (usb_ep_autoconfig_ss) to be used instead of
the existing usb_ep_autoconfig when working in SS mode and there is a
need to search for an endpoint according to the number of required
streams.

Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

---
drivers/usb/gadget/epautoconf.c | 125 +++++++++++++++++++++++++++++++--------
include/linux/usb/gadget.h | 13 ++++
2 files changed, 113 insertions(+), 25 deletions(-)

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 0022d44..91c032f 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
*
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 318c815..1ab9951 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -27,6 +27,7 @@ struct usb_ep;
* field, and the usb controller needs one, it is responsible
* for mapping and unmapping the buffer.
* @length: Length of that data
+ * @stream_id: The stream id, when USB3.0 bulk streams are being used
* @no_interrupt: If true, hints that no completion irq is needed.
* Helpful sometimes with deep request queues that are handled
* directly by DMA controllers.
@@ -81,6 +82,7 @@ struct usb_request {
unsigned length;
dma_addr_t dma;

+ unsigned stream_id:16;
unsigned no_interrupt:1;
unsigned zero:1;
unsigned short_not_ok:1;
@@ -131,11 +133,15 @@ struct usb_ep_ops {
* @maxpacket:The maximum packet size used on this endpoint. The initial
* value can sometimes be reduced (hardware allowing), according to
* the endpoint descriptor used to configure the endpoint.
+ * @max_streams: The maximum number of streams supported
+ * by this EP (0 - 16, actual number is 2^n)
* @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.
+ * @comp_desc: In case of SuperSpeed support, this is the endpoint companion
+ * descriptor that is used to configure the endpoint
*
* the bus controller driver lists all the general purpose endpoints in
* gadget->ep_list. the control endpoint (gadget->ep0) is not in that list,
@@ -148,8 +154,10 @@ struct usb_ep {
const struct usb_ep_ops *ops;
struct list_head ep_list;
unsigned maxpacket:16;
+ unsigned max_streams:16;
u8 address;
const struct usb_endpoint_descriptor *desc;
+ const struct usb_ss_ep_comp_descriptor *comp_desc;
};

/*-------------------------------------------------------------------------*/
@@ -887,6 +895,11 @@ static inline void usb_free_descriptors(struct usb_descriptor_header **v)
extern struct usb_ep *usb_ep_autoconfig(struct usb_gadget *,
struct usb_endpoint_descriptor *);

+
+extern struct usb_ep *usb_ep_autoconfig_ss(struct usb_gadget *,
+ struct usb_endpoint_descriptor *,
+ struct usb_ss_ep_comp_descriptor *);
+
extern void usb_ep_autoconfig_reset(struct usb_gadget *);

#endif /* __LINUX_USB_GADGET_H */
--
1.7.3.3

--
Sent by an employee of the Qualcomm Innovation Center, Inc.