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>
---
include/linux/usb/gadget.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 23b3bfd0a842..260d972489bd 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -442,6 +442,22 @@ static inline void usb_ep_fifo_flush(struct usb_ep *ep)
}
+static inline size_t usb_ep_align_maxpacketsize(struct usb_ep *ep, size_t len)
+{
+ int aligned;
+
+ if (ep->desc->bmAttributes & USB_ENDPOINT_XFER_INT)
+ /*
+ * Interrupt eps don't need max packet size to be power of 2,
+ * so can't use cheap IS_ALIGNED() macro.
+ */
+ aligned = !(len % ep->desc->wMaxPacketSize);
+ else
+ aligned = IS_ALIGNED(len, ep->desc->wMaxPacketSize);
+
+ return aligned ? len : round_up(len, (size_t)ep->desc->wMaxPacketSize);
+}
+
/*-------------------------------------------------------------------------*/
struct usb_dcd_config_params {
@@ -502,6 +518,8 @@ 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 +559,7 @@ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
