From 0b2d2bbade59ab2067f326d6dbc2628bee227fd5 Mon Sep 17 00:00:00 2001 From: David Cohen 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 Acked-by: Michal Nazarewicz Signed-off-by: David Cohen Signed-off-by: Felipe Balbi --- 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 23b3bfd0a84..cae8a621655 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 -- 2.46.0