From 0b2d2bbade59ab2067f326d6dbc2628bee227fd5 Mon Sep 17 00:00:00 2001
From: David Cohen <david.a.cohen@linux.intel.com>
Date: Mon, 9 Dec 2013 15:55:35 -0800
Subject: [PATCH] usb: gadget: add quirk_ep_out_aligned_size field to struct
usb_gadget
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.
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
include/linux/usb/gadget.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 23b3bfd0a8429..cae8a6216551c 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -502,6 +502,8 @@ 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 +543,7 @@ 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))
@@ -558,6 +561,23 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
list_for_each_entry(tmp, &(gadget)->ep_list, ep_list)
+/**
+ * usb_ep_align_maybe - returns @len aligned to ep's maxpacketsize if gadget
+ * requires quirk_ep_out_aligned_size, otherwise reguens len.
+ * @g: controller to check for quirk
+ * @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 check and maybe
+ * align buffer's size to an ep's maxpacketsize.
+ */
+static inline size_t
+usb_ep_align_maybe(struct usb_gadget *g, struct usb_ep *ep, size_t len)
+{
+ return !g->quirk_ep_out_aligned_size ? len :
+ round_up(len, (size_t)ep->desc->wMaxPacketSize);
+}
+
/**
* gadget_is_dualspeed - return true iff the hardware handles high speed
* @g: controller that might support both high and full speeds
--
2.30.2