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 #include "gadget_chips.h"
24 
25 #define QMULT_DEFAULT 5
26 
27 /*
28  * dev_addr: initial value
29  * changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx"
30  * host_addr: this address is invisible to ifconfig
31  */
32 #define USB_ETHERNET_MODULE_PARAMETERS() \
33 	static unsigned qmult = QMULT_DEFAULT;				\
34 	module_param(qmult, uint, S_IRUGO|S_IWUSR);			\
35 	MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");\
36 									\
37 	static char *dev_addr;						\
38 	module_param(dev_addr, charp, S_IRUGO);				\
39 	MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");		\
40 									\
41 	static char *host_addr;						\
42 	module_param(host_addr, charp, S_IRUGO);			\
43 	MODULE_PARM_DESC(host_addr, "Host Ethernet Address")
44 
45 struct eth_dev;
46 
47 /*
48  * This represents the USB side of an "ethernet" link, managed by a USB
49  * function which provides control and (maybe) framing.  Two functions
50  * in different configurations could share the same ethernet link/netdev,
51  * using different host interaction models.
52  *
53  * There is a current limitation that only one instance of this link may
54  * be present in any given configuration.  When that's a problem, network
55  * layer facilities can be used to package multiple logical links on this
56  * single "physical" one.
57  */
58 struct gether {
59 	struct usb_function		func;
60 
61 	/* updated by gether_{connect,disconnect} */
62 	struct eth_dev			*ioport;
63 
64 	/* endpoints handle full and/or high speeds */
65 	struct usb_ep			*in_ep;
66 	struct usb_ep			*out_ep;
67 
68 	bool				is_zlp_ok;
69 
70 	u16				cdc_filter;
71 
72 	/* hooks for added framing, as needed for RNDIS and EEM. */
73 	u32				header_len;
74 	/* NCM requires fixed size bundles */
75 	bool				is_fixed;
76 	u32				fixed_out_len;
77 	u32				fixed_in_len;
78 	bool				supports_multi_frame;
79 	struct sk_buff			*(*wrap)(struct gether *port,
80 						struct sk_buff *skb);
81 	int				(*unwrap)(struct gether *port,
82 						struct sk_buff *skb,
83 						struct sk_buff_head *list);
84 
85 	/* called on network open/close */
86 	void				(*open)(struct gether *);
87 	void				(*close)(struct gether *);
88 };
89 
90 #define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
91 			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
92 			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
93 			|USB_CDC_PACKET_TYPE_DIRECTED)
94 
95 /* variant of gether_setup that allows customizing network device name */
96 struct eth_dev *gether_setup_name(struct usb_gadget *g,
97 		const char *dev_addr, const char *host_addr,
98 		u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
99 
100 /* netdev setup/teardown as directed by the gadget driver */
101 /* gether_setup - initialize one ethernet-over-usb link
102  * @g: gadget to associated with these links
103  * @ethaddr: NULL, or a buffer in which the ethernet address of the
104  *	host side of the link is recorded
105  * Context: may sleep
106  *
107  * This sets up the single network link that may be exported by a
108  * gadget driver using this framework.  The link layer addresses are
109  * set up using module parameters.
110  *
111  * Returns a eth_dev pointer on success, or an ERR_PTR on failure
112  */
113 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
114 		const char *dev_addr, const char *host_addr,
115 		u8 ethaddr[ETH_ALEN], unsigned qmult)
116 {
117 	return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
118 }
119 
120 /*
121  * variant of gether_setup_default that allows customizing
122  * network device name
123  */
124 struct net_device *gether_setup_name_default(const char *netname);
125 
126 /*
127  * gether_register_netdev - register the net device
128  * @net: net device to register
129  *
130  * Registers the net device associated with this ethernet-over-usb link
131  *
132  */
133 int gether_register_netdev(struct net_device *net);
134 
135 /* gether_setup_default - initialize one ethernet-over-usb link
136  * Context: may sleep
137  *
138  * This sets up the single network link that may be exported by a
139  * gadget driver using this framework.  The link layer addresses
140  * are set to random values.
141  *
142  * Returns negative errno, or zero on success
143  */
144 static inline struct net_device *gether_setup_default(void)
145 {
146 	return gether_setup_name_default("usb");
147 }
148 
149 /**
150  * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
151  * @net: device representing this link
152  * @g: the gadget to initialize with
153  *
154  * This associates one ethernet-over-usb link with a gadget.
155  */
156 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
157 
158 /**
159  * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
160  * @net: device representing this link
161  * @dev_addr: eth address of this device
162  *
163  * This sets the device-side Ethernet address of this ethernet-over-usb link
164  * if dev_addr is correct.
165  * Returns negative errno if the new address is incorrect.
166  */
167 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
168 
169 /**
170  * gether_get_dev_addr - get an ethernet-over-usb link eth address
171  * @net: device representing this link
172  * @dev_addr: place to store device's eth address
173  * @len: length of the @dev_addr buffer
174  *
175  * This gets the device-side Ethernet address of this ethernet-over-usb link.
176  * Returns zero on success, else negative errno.
177  */
178 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
179 
180 /**
181  * gether_set_host_addr - initialize an ethernet-over-usb link with host address
182  * @net: device representing this link
183  * @host_addr: eth address of the host
184  *
185  * This sets the host-side Ethernet address of this ethernet-over-usb link
186  * if host_addr is correct.
187  * Returns negative errno if the new address is incorrect.
188  */
189 int gether_set_host_addr(struct net_device *net, const char *host_addr);
190 
191 /**
192  * gether_get_host_addr - get an ethernet-over-usb link host address
193  * @net: device representing this link
194  * @host_addr: place to store eth address of the host
195  * @len: length of the @host_addr buffer
196  *
197  * This gets the host-side Ethernet address of this ethernet-over-usb link.
198  * Returns zero on success, else negative errno.
199  */
200 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
201 
202 /**
203  * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
204  * @net: device representing this link
205  * @host_addr: place to store eth address of the host
206  * @len: length of the @host_addr buffer
207  *
208  * This gets the CDC formatted host-side Ethernet address of this
209  * ethernet-over-usb link.
210  * Returns zero on success, else negative errno.
211  */
212 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
213 
214 /**
215  * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
216  * @net: device representing this link
217  * @host_mac: place to store the eth address of the host
218  *
219  * This gets the binary formatted host-side Ethernet address of this
220  * ethernet-over-usb link.
221  */
222 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
223 
224 /**
225  * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
226  * @net: device representing this link
227  * @qmult: queue multiplier
228  *
229  * This sets the queue length multiplier of this ethernet-over-usb link.
230  * For higher speeds use longer queues.
231  */
232 void gether_set_qmult(struct net_device *net, unsigned qmult);
233 
234 /**
235  * gether_get_qmult - get an ethernet-over-usb link multiplier
236  * @net: device representing this link
237  *
238  * This gets the queue length multiplier of this ethernet-over-usb link.
239  */
240 unsigned gether_get_qmult(struct net_device *net);
241 
242 /**
243  * gether_get_ifname - get an ethernet-over-usb link interface name
244  * @net: device representing this link
245  * @name: place to store the interface name
246  * @len: length of the @name buffer
247  *
248  * This gets the interface name of this ethernet-over-usb link.
249  * Returns zero on success, else negative errno.
250  */
251 int gether_get_ifname(struct net_device *net, char *name, int len);
252 
253 void gether_cleanup(struct eth_dev *dev);
254 
255 /* connect/disconnect is handled by individual functions */
256 struct net_device *gether_connect(struct gether *);
257 void gether_disconnect(struct gether *);
258 
259 /* Some controllers can't support CDC Ethernet (ECM) ... */
260 static inline bool can_support_ecm(struct usb_gadget *gadget)
261 {
262 	if (!gadget_supports_altsettings(gadget))
263 		return false;
264 
265 	/* Everything else is *presumably* fine ... but this is a bit
266 	 * chancy, so be **CERTAIN** there are no hardware issues with
267 	 * your controller.  Add it above if it can't handle CDC.
268 	 */
269 	return true;
270 }
271 
272 #endif /* __U_ETHER_H */
273