Due to USB controllers may have different restrictions, usb gadget layer
needs to provide a generic way to inform gadget functions to complain
with non-standard requirements.
This patch adds 'quirk_ep_out_aligned_size' field to struct usb_gadget
to inform when controller's epout requires buffer size to be aligned to
MaxPacketSize. A helper is also provided to align buffer size when
necessary.
Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
---
Changes from v4 to v4.1:
- Simplified usb_ep_align_maxpacketsize() macro as per Alen Stern's request
include/linux/usb/gadget.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 23b3bfd0a842..41e8834af57d 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -441,6 +441,19 @@ static inline void usb_ep_fifo_flush(struct usb_ep *ep)
ep->ops->fifo_flush(ep);
}
+/**
+ * usb_ep_align_maxpacketsize - returns @len aligned to ep's maxpacketsize
+ * @ep: the endpoint whose maxpacketsize is used to align @len
+ * @len: buffer size's length to align to @ep's maxpacketsize
+ *
+ * This helper is used in case it's required for any reason to align buffer's
+ * size to an ep's maxpacketsize.
+ */
+static inline size_t usb_ep_align_maxpacketsize(struct usb_ep *ep, size_t len)
+{
+ return round_up(len, (size_t)ep->desc->wMaxPacketSize);
+}
+
/*-------------------------------------------------------------------------*/
@@ -502,6 +515,8 @@ struct usb_gadget_ops {
* only supports HNP on a different root port.
* @b_hnp_enable: OTG device feature flag, indicating that the A-Host
* enabled HNP support.
+ * @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
+ * MaxPacketSize.
*
* Gadgets have a mostly-portable "gadget driver" implementing device
* functions, handling all usb configurations and interfaces. Gadget
@@ -541,6 +556,7 @@ struct usb_gadget {
unsigned b_hnp_enable:1;
unsigned a_hnp_support:1;
unsigned a_alt_hnp_support:1;
+ unsigned quirk_ep_out_aligned_size:1;
};
#define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
--
1.8.4.rc3
--
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