1/*
  2 * u_ether.h -- interface to USB gadget "ethernet link" utilities
  3 *
  4 * Copyright (C) 2003-2005,2008 David Brownell
  5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
  6 * Copyright (C) 2008 Nokia Corporation
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License as published by
 10 * the Free Software Foundation; either version 2 of the License, or
 11 * (at your option) any later version.
 12 */
 13
 14#ifndef __U_ETHER_H
 15#define __U_ETHER_H
 16
 17#include <linux/err.h>
 18#include <linux/if_ether.h>
 19#include <linux/usb/composite.h>
 20#include <linux/usb/cdc.h>
 21
 22#include "gadget_chips.h"
 23
 24
 25/*
 26 * This represents the USB side of an "ethernet" link, managed by a USB
 27 * function which provides control and (maybe) framing.  Two functions
 28 * in different configurations could share the same ethernet link/netdev,
 29 * using different host interaction models.
 30 *
 31 * There is a current limitation that only one instance of this link may
 32 * be present in any given configuration.  When that's a problem, network
 33 * layer facilities can be used to package multiple logical links on this
 34 * single "physical" one.
 35 */
 36struct gether {
 37	struct usb_function		func;
 38
 39	/* updated by gether_{connect,disconnect} */
 40	struct eth_dev			*ioport;
 41
 42	/* endpoints handle full and/or high speeds */
 43	struct usb_ep			*in_ep;
 44	struct usb_ep			*out_ep;
 45
 46	bool				is_zlp_ok;
 47
 48	u16				cdc_filter;
 49
 50	/* hooks for added framing, as needed for RNDIS and EEM. */
 51	u32				header_len;
 52	/* NCM requires fixed size bundles */
 53	bool				is_fixed;
 54	u32				fixed_out_len;
 55	u32				fixed_in_len;
 56	struct sk_buff			*(*wrap)(struct gether *port,
 57						struct sk_buff *skb);
 58	int				(*unwrap)(struct gether *port,
 59						struct sk_buff *skb,
 60						struct sk_buff_head *list);
 61
 62	/* called on network open/close */
 63	void				(*open)(struct gether *);
 64	void				(*close)(struct gether *);
 65};
 66
 67#define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
 68			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
 69			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
 70			|USB_CDC_PACKET_TYPE_DIRECTED)
 71
 72/* variant of gether_setup that allows customizing network device name */
 73int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
 74		const char *netname);
 75
 76/* netdev setup/teardown as directed by the gadget driver */
 77/* gether_setup - initialize one ethernet-over-usb link
 78 * @g: gadget to associated with these links
 79 * @ethaddr: NULL, or a buffer in which the ethernet address of the
 80 *	host side of the link is recorded
 81 * Context: may sleep
 82 *
 83 * This sets up the single network link that may be exported by a
 84 * gadget driver using this framework.  The link layer addresses are
 85 * set up using module parameters.
 86 *
 87 * Returns negative errno, or zero on success
 88 */
 89static inline int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
 90{
 91	return gether_setup_name(g, ethaddr, "usb");
 92}
 93
 94void gether_cleanup(void);
 95
 96/* connect/disconnect is handled by individual functions */
 97struct net_device *gether_connect(struct gether *);
 98void gether_disconnect(struct gether *);
 99
100/* Some controllers can't support CDC Ethernet (ECM) ... */
101static inline bool can_support_ecm(struct usb_gadget *gadget)
102{
103	if (!gadget_supports_altsettings(gadget))
104		return false;
105
106	/* Everything else is *presumably* fine ... but this is a bit
107	 * chancy, so be **CERTAIN** there are no hardware issues with
108	 * your controller.  Add it above if it can't handle CDC.
109	 */
110	return true;
111}
112
113/* each configuration may bind one instance of an ethernet link */
114int geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
115int ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
116int ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
117int eem_bind_config(struct usb_configuration *c);
118
119#ifdef USB_ETH_RNDIS
120
121int rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
122				u32 vendorID, const char *manufacturer);
123
124#else
125
126static inline int
127rndis_bind_config_vendor(struct usb_configuration *c, u8 ethaddr[ETH_ALEN],
128				u32 vendorID, const char *manufacturer)
129{
130	return 0;
131}
132
133#endif
134
135/**
136 * rndis_bind_config - add RNDIS network link to a configuration
137 * @c: the configuration to support the network link
138 * @ethaddr: a buffer in which the ethernet address of the host side
139 *	side of the link was recorded
140 * Context: single threaded during gadget setup
141 *
142 * Returns zero on success, else negative errno.
143 *
144 * Caller must have called @gether_setup().  Caller is also responsible
145 * for calling @gether_cleanup() before module unload.
146 */
147static inline int rndis_bind_config(struct usb_configuration *c,
148				    u8 ethaddr[ETH_ALEN])
149{
150	return rndis_bind_config_vendor(c, ethaddr, 0, NULL);
151}
152
153
154#endif /* __U_ETHER_H */