xref: /linux/drivers/usb/gadget/function/u_ether.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 #include <linux/netdevice.h>
22 
23 #define QMULT_DEFAULT 5
24 
25 /*
26  * dev_addr: initial value
27  * changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx"
28  * host_addr: this address is invisible to ifconfig
29  */
30 #define USB_ETHERNET_MODULE_PARAMETERS() \
31 	static unsigned qmult = QMULT_DEFAULT;				\
32 	module_param(qmult, uint, S_IRUGO|S_IWUSR);			\
33 	MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");\
34 									\
35 	static char *dev_addr;						\
36 	module_param(dev_addr, charp, S_IRUGO);				\
37 	MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");		\
38 									\
39 	static char *host_addr;						\
40 	module_param(host_addr, charp, S_IRUGO);			\
41 	MODULE_PARM_DESC(host_addr, "Host Ethernet Address")
42 
43 struct eth_dev;
44 
45 /*
46  * This represents the USB side of an "ethernet" link, managed by a USB
47  * function which provides control and (maybe) framing.  Two functions
48  * in different configurations could share the same ethernet link/netdev,
49  * using different host interaction models.
50  *
51  * There is a current limitation that only one instance of this link may
52  * be present in any given configuration.  When that's a problem, network
53  * layer facilities can be used to package multiple logical links on this
54  * single "physical" one.
55  */
56 struct gether {
57 	struct usb_function		func;
58 
59 	/* updated by gether_{connect,disconnect} */
60 	struct eth_dev			*ioport;
61 
62 	/* endpoints handle full and/or high speeds */
63 	struct usb_ep			*in_ep;
64 	struct usb_ep			*out_ep;
65 
66 	bool				is_zlp_ok;
67 	bool				no_skb_reserve;
68 
69 	u16				cdc_filter;
70 
71 	/* hooks for added framing, as needed for RNDIS and EEM. */
72 	u32				header_len;
73 	/* NCM requires fixed size bundles */
74 	bool				is_fixed;
75 	u32				fixed_out_len;
76 	u32				fixed_in_len;
77 	bool				supports_multi_frame;
78 	struct sk_buff			*(*wrap)(struct gether *port,
79 						struct sk_buff *skb);
80 	int				(*unwrap)(struct gether *port,
81 						struct sk_buff *skb,
82 						struct sk_buff_head *list);
83 
84 	/* called on network open/close */
85 	void				(*open)(struct gether *);
86 	void				(*close)(struct gether *);
87 };
88 
89 #define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
90 			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
91 			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
92 			|USB_CDC_PACKET_TYPE_DIRECTED)
93 
94 /* variant of gether_setup that allows customizing network device name */
95 struct eth_dev *gether_setup_name(struct usb_gadget *g,
96 		const char *dev_addr, const char *host_addr,
97 		u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
98 
99 /* netdev setup/teardown as directed by the gadget driver */
100 /* gether_setup - initialize one ethernet-over-usb link
101  * @g: gadget to associated with these links
102  * @ethaddr: NULL, or a buffer in which the ethernet address of the
103  *	host side of the link is recorded
104  * Context: may sleep
105  *
106  * This sets up the single network link that may be exported by a
107  * gadget driver using this framework.  The link layer addresses are
108  * set up using module parameters.
109  *
110  * Returns a eth_dev pointer on success, or an ERR_PTR on failure
111  */
112 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
113 		const char *dev_addr, const char *host_addr,
114 		u8 ethaddr[ETH_ALEN], unsigned qmult)
115 {
116 	return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
117 }
118 
119 /*
120  * variant of gether_setup_default that allows customizing
121  * network device name
122  */
123 struct net_device *gether_setup_name_default(const char *netname);
124 
125 /*
126  * gether_register_netdev - register the net device
127  * @net: net device to register
128  *
129  * Registers the net device associated with this ethernet-over-usb link
130  *
131  */
132 int gether_register_netdev(struct net_device *net);
133 
134 /* gether_setup_default - initialize one ethernet-over-usb link
135  * Context: may sleep
136  *
137  * This sets up the single network link that may be exported by a
138  * gadget driver using this framework.  The link layer addresses
139  * are set to random values.
140  *
141  * Returns negative errno, or zero on success
142  */
143 static inline struct net_device *gether_setup_default(void)
144 {
145 	return gether_setup_name_default("usb");
146 }
147 
148 /**
149  * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
150  * @net: device representing this link
151  * @g: the gadget to initialize with
152  *
153  * This associates one ethernet-over-usb link with a gadget.
154  */
155 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
156 
157 /**
158  * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
159  * @net: device representing this link
160  * @dev_addr: eth address of this device
161  *
162  * This sets the device-side Ethernet address of this ethernet-over-usb link
163  * if dev_addr is correct.
164  * Returns negative errno if the new address is incorrect.
165  */
166 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
167 
168 /**
169  * gether_get_dev_addr - get an ethernet-over-usb link eth address
170  * @net: device representing this link
171  * @dev_addr: place to store device's eth address
172  * @len: length of the @dev_addr buffer
173  *
174  * This gets the device-side Ethernet address of this ethernet-over-usb link.
175  * Returns zero on success, else negative errno.
176  */
177 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
178 
179 /**
180  * gether_set_host_addr - initialize an ethernet-over-usb link with host address
181  * @net: device representing this link
182  * @host_addr: eth address of the host
183  *
184  * This sets the host-side Ethernet address of this ethernet-over-usb link
185  * if host_addr is correct.
186  * Returns negative errno if the new address is incorrect.
187  */
188 int gether_set_host_addr(struct net_device *net, const char *host_addr);
189 
190 /**
191  * gether_get_host_addr - get an ethernet-over-usb link host address
192  * @net: device representing this link
193  * @host_addr: place to store eth address of the host
194  * @len: length of the @host_addr buffer
195  *
196  * This gets the host-side Ethernet address of this ethernet-over-usb link.
197  * Returns zero on success, else negative errno.
198  */
199 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
200 
201 /**
202  * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
203  * @net: device representing this link
204  * @host_addr: place to store eth address of the host
205  * @len: length of the @host_addr buffer
206  *
207  * This gets the CDC formatted host-side Ethernet address of this
208  * ethernet-over-usb link.
209  * Returns zero on success, else negative errno.
210  */
211 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
212 
213 /**
214  * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
215  * @net: device representing this link
216  * @host_mac: place to store the eth address of the host
217  *
218  * This gets the binary formatted host-side Ethernet address of this
219  * ethernet-over-usb link.
220  */
221 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
222 
223 /**
224  * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
225  * @net: device representing this link
226  * @qmult: queue multiplier
227  *
228  * This sets the queue length multiplier of this ethernet-over-usb link.
229  * For higher speeds use longer queues.
230  */
231 void gether_set_qmult(struct net_device *net, unsigned qmult);
232 
233 /**
234  * gether_get_qmult - get an ethernet-over-usb link multiplier
235  * @net: device representing this link
236  *
237  * This gets the queue length multiplier of this ethernet-over-usb link.
238  */
239 unsigned gether_get_qmult(struct net_device *net);
240 
241 /**
242  * gether_get_ifname - get an ethernet-over-usb link interface name
243  * @net: device representing this link
244  * @name: place to store the interface name
245  * @len: length of the @name buffer
246  *
247  * This gets the interface name of this ethernet-over-usb link.
248  * Returns zero on success, else negative errno.
249  */
250 int gether_get_ifname(struct net_device *net, char *name, int len);
251 
252 void gether_cleanup(struct eth_dev *dev);
253 
254 /* connect/disconnect is handled by individual functions */
255 struct net_device *gether_connect(struct gether *);
256 void gether_disconnect(struct gether *);
257 
258 /* Some controllers can't support CDC Ethernet (ECM) ... */
259 static inline bool can_support_ecm(struct usb_gadget *gadget)
260 {
261 	if (!gadget_is_altset_supported(gadget))
262 		return false;
263 
264 	/* Everything else is *presumably* fine ... but this is a bit
265 	 * chancy, so be **CERTAIN** there are no hardware issues with
266 	 * your controller.  Add it above if it can't handle CDC.
267 	 */
268 	return true;
269 }
270 
271 #endif /* __U_ETHER_H */
272