[RFC/PATCH] usb: Add streams support to epautoconf.

From: Maya Erez
Date: Sun Nov 14 2010 - 01:24:52 EST


- Add the capability to search for an EP with a required number of streams.
- Add a gadget_op to allow DCDs to use a proprietary search algorithm
for required and minimum number of streams.

Signed-off-by: Maya Erez <merez@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/epautoconf.c | 141 ++++++++++++++++++++++++++++++++-------
include/linux/usb/gadget.h | 14 ++++-
2 files changed, 129 insertions(+), 26 deletions(-)

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 8a83248..bbac2fb 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;
@@ -128,6 +131,22 @@ 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 == type) {
+ if (ep_comp) {
+ num_req_streams = ep_comp->bmAttributes & 0x1f;
+ if (num_req_streams > ep->num_supported_strms)
+ return 0;
+ /* Update the ep_comp descriptor if needed */
+ if (num_req_streams != ep->num_supported_strms)
+ ep_comp->bmAttributes = ep->num_supported_strms;
+ }
+
+ }
+
/* endpoint maxpacket size is an input parameter, except for bulk
* where it's an output parameter representing the full speed limit.
* the usb spec fixes high speed bulk maxpacket at 512 bytes.
@@ -200,43 +219,74 @@ 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.
+ * @min_num_of_req_strms: A minimum number of streams that allow
+ * the FD to be functional
*
- * 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 and min_num_of_req_strms parameters.
+ *
+ * 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.
+ * To allow controller special algorithms, we added a new gadget
+ * op for assigning an ep.
+ *
+ * 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,
+ int min_num_of_req_strms
)
{
struct usb_ep *ep;
u8 type;

+ /* Call the controller specific function for assigning an EP
+ * if it is defined
+ */
+ if (gadget->ops->ep_assign) {
+ struct usb_ep *assigned_ep = NULL;
+ gadget->ops->ep_assign(gadget, desc, ep_comp,
+ min_num_of_req_strms, &assigned_ep);
+ return assigned_ep;
+ }
+
type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;

/* First, apply chip-specific "best usage" knowledge.
@@ -245,23 +295,24 @@ 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;
}

@@ -280,14 +331,14 @@ 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;
}

@@ -296,6 +347,46 @@ 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, 0);
+}
+
+
+/**
* 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 d3ef42d..bfbd32f 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -419,7 +419,7 @@ static inline void usb_ep_fifo_flush(struct usb_ep *ep)
struct usb_gadget;

/* the rest of the api to the controller hardware: device operations,
- * which don't involve endpoints (or i/o).
+ * which don't involve i/o.
*/
struct usb_gadget_ops {
int (*get_frame)(struct usb_gadget *);
@@ -430,6 +430,12 @@ struct usb_gadget_ops {
int (*pullup) (struct usb_gadget *, int is_on);
int (*ioctl)(struct usb_gadget *,
unsigned code, unsigned long param);
+ int (*ep_assign) (struct usb_gadget *,
+ struct usb_endpoint_descriptor *,
+ struct usb_ss_ep_comp_descriptor *,
+ int min_num_of_req_strms,
+ struct usb_ep **returned_ep);
+
};

/**
@@ -896,6 +902,12 @@ 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 *) __devinit;

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

#endif /* __LINUX_USB_GADGET_H */
--
1.6.3.3
--
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Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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