drivers/usb/gadget/u_ether.h

/*
 * u_ether.h -- interface to USB gadget "ethernet link" utilities
 *
 * Copyright (C) 2003-2005,2008 David Brownell
 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
 * Copyright (C) 2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef __U_ETHER_H
#define __U_ETHER_H

#include <linux/err.h>
#include <linux/if_ether.h>
#include <linux/usb/composite.h>
#include <linux/usb/cdc.h>

#include "gadget_chips.h"


/*
 * This represents the USB side of an "ethernet" link, managed by a USB
 * function which provides control and (maybe) framing.  Two functions
 * in different configurations could share the same ethernet link/netdev.
 *
 * There is currently a limitation that one instance of this function
 * may be present in any given configuration.
 */
struct gether {
	struct usb_function		func;

	/* updated by gether_{connect,disconnect} */
	struct eth_dev			*ioport;

	/* endpoints handle full and/or high speeds */
	struct usb_ep			*in_ep;
	struct usb_ep			*out_ep;

	/* descriptors match device speed at gether_connect() time */
	struct usb_endpoint_descriptor	*in;
	struct usb_endpoint_descriptor	*out;

	bool				is_zlp_ok;

	u16				cdc_filter;

	/* hooks for added framing, as needed for RNDIS and EEM.
	 * we currently don't support multiple frames per SKB.
	 */
	u32				header_len;
	struct sk_buff			*(*wrap)(struct sk_buff *skb);
	int				(*unwrap)(struct sk_buff *skb);

	/* called on network open/close */
	void				(*open)(struct gether *);
	void				(*close)(struct gether *);
};

#define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
			|USB_CDC_PACKET_TYPE_DIRECTED)


/* netdev setup/teardown as directed by the gadget driver */
int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]);
void gether_cleanup(void);

/* connect/disconnect is handled by individual functions */
struct net_device *gether_connect(struct gether *);
void gether_disconnect(struct gether *);

/* Some controllers can't support CDC Ethernet (ECM) ... */
static inline bool can_support_ecm(struct usb_gadget *gadget)
{
	if (!gadget_supports_altsettings(gadget))
		return false;

	/* SA1100 can do ECM, *without* status endpoint ... but we'll
	 * only use it in non-ECM mode for backwards compatibility
	 * (and since we currently require a status endpoint)
	 */
	if (gadget_is_sa1100(gadget))
		return false;

	/* Everything else is *presumably* fine ... but this is a bit
	 * chancy, so be **CERTAIN** there are no hardware issues with
	 * your controller.  Add it above if it can't handle CDC.
	 */
	return true;
}

/* each configuration may bind one instance of an ethernet link */
int geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
int ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);

#endif /* __U_ETHER_H */