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  */
36 struct 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 
73 /* netdev setup/teardown as directed by the gadget driver */
74 int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]);
75 void gether_cleanup(void);
76 
77 /* connect/disconnect is handled by individual functions */
78 struct net_device *gether_connect(struct gether *);
79 void gether_disconnect(struct gether *);
80 
81 /* Some controllers can't support CDC Ethernet (ECM) ... */
can_support_ecm(struct usb_gadget * gadget)82 static inline bool can_support_ecm(struct usb_gadget *gadget)
83 {
84 	if (!gadget_supports_altsettings(gadget))
85 		return false;
86 
87 	/* Everything else is *presumably* fine ... but this is a bit
88 	 * chancy, so be **CERTAIN** there are no hardware issues with
89 	 * your controller.  Add it above if it can't handle CDC.
90 	 */
91 	return true;
92 }
93 
94 /* each configuration may bind one instance of an ethernet link */
95 int geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
96 int ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
97 int ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
98 int eem_bind_config(struct usb_configuration *c);
99 
100 #ifdef USB_ETH_RNDIS
101 
102 int rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
103 
104 #else
105 
106 static inline int
rndis_bind_config(struct usb_configuration * c,u8 ethaddr[ETH_ALEN])107 rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
108 {
109 	return 0;
110 }
111 
112 #endif
113 
114 #endif /* __U_ETHER_H */
115