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u_ether.h
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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 
49 
50  /* hooks for added framing, as needed for RNDIS and EEM. */
52  /* NCM requires fixed size bundles */
53  bool is_fixed;
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 */
73 int 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  */
89 static inline int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
90 {
91  return gether_setup_name(g, ethaddr, "usb");
92 }
93 
94 void gether_cleanup(void);
95 
96 /* connect/disconnect is handled by individual functions */
97 struct net_device *gether_connect(struct gether *);
98 void gether_disconnect(struct gether *);
99 
100 /* Some controllers can't support CDC Ethernet (ECM) ... */
101 static 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 */
114 int geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
115 int ecm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
116 int ncm_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
117 int eem_bind_config(struct usb_configuration *c);
118 
119 #ifdef USB_ETH_RNDIS
120 
122  u32 vendorID, const char *manufacturer);
123 
124 #else
125 
126 static inline int
128  u32 vendorID, const char *manufacturer)
129 {
130  return 0;
131 }
132 
133 #endif
134 
147 static 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 */