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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 #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 	unsigned		ul_max_pkts_per_xfer;
79 	unsigned		dl_max_pkts_per_xfer;
80 	bool				multi_pkt_xfer;
81 	bool				supports_multi_frame;
82 	struct sk_buff			*(*wrap)(struct gether *port,
83 						struct sk_buff *skb);
84 	int				(*unwrap)(struct gether *port,
85 						struct sk_buff *skb,
86 						struct sk_buff_head *list);
87 
88 	/* called on network open/close */
89 	void				(*open)(struct gether *);
90 	void				(*close)(struct gether *);
91 };
92 
93 #define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
94 			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
95 			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
96 			|USB_CDC_PACKET_TYPE_DIRECTED)
97 
98 /* variant of gether_setup that allows customizing network device name */
99 struct eth_dev *gether_setup_name(struct usb_gadget *g,
100 		const char *dev_addr, const char *host_addr,
101 		u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
102 
103 /* netdev setup/teardown as directed by the gadget driver */
104 /* gether_setup - initialize one ethernet-over-usb link
105  * @g: gadget to associated with these links
106  * @ethaddr: NULL, or a buffer in which the ethernet address of the
107  *	host side of the link is recorded
108  * Context: may sleep
109  *
110  * This sets up the single network link that may be exported by a
111  * gadget driver using this framework.  The link layer addresses are
112  * set up using module parameters.
113  *
114  * Returns a eth_dev pointer on success, or an ERR_PTR on failure
115  */
gether_setup(struct usb_gadget * g,const char * dev_addr,const char * host_addr,u8 ethaddr[ETH_ALEN],unsigned qmult)116 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
117 		const char *dev_addr, const char *host_addr,
118 		u8 ethaddr[ETH_ALEN], unsigned qmult)
119 {
120 	return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
121 }
122 
123 /*
124  * variant of gether_setup_default that allows customizing
125  * network device name
126  */
127 struct net_device *gether_setup_name_default(const char *netname);
128 
129 /*
130  * gether_register_netdev - register the net device
131  * @net: net device to register
132  *
133  * Registers the net device associated with this ethernet-over-usb link
134  *
135  */
136 int gether_register_netdev(struct net_device *net);
137 
138 /* gether_setup_default - initialize one ethernet-over-usb link
139  * Context: may sleep
140  *
141  * This sets up the single network link that may be exported by a
142  * gadget driver using this framework.  The link layer addresses
143  * are set to random values.
144  *
145  * Returns negative errno, or zero on success
146  */
gether_setup_default(void)147 static inline struct net_device *gether_setup_default(void)
148 {
149 	return gether_setup_name_default("usb");
150 }
151 
152 /**
153  * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
154  * @net: device representing this link
155  * @g: the gadget to initialize with
156  *
157  * This associates one ethernet-over-usb link with a gadget.
158  */
159 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
160 
161 /**
162  * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
163  * @net: device representing this link
164  * @dev_addr: eth address of this device
165  *
166  * This sets the device-side Ethernet address of this ethernet-over-usb link
167  * if dev_addr is correct.
168  * Returns negative errno if the new address is incorrect.
169  */
170 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
171 
172 /**
173  * gether_get_dev_addr - get an ethernet-over-usb link eth address
174  * @net: device representing this link
175  * @dev_addr: place to store device's eth address
176  * @len: length of the @dev_addr buffer
177  *
178  * This gets the device-side Ethernet address of this ethernet-over-usb link.
179  * Returns zero on success, else negative errno.
180  */
181 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
182 
183 /**
184  * gether_set_host_addr - initialize an ethernet-over-usb link with host address
185  * @net: device representing this link
186  * @host_addr: eth address of the host
187  *
188  * This sets the host-side Ethernet address of this ethernet-over-usb link
189  * if host_addr is correct.
190  * Returns negative errno if the new address is incorrect.
191  */
192 int gether_set_host_addr(struct net_device *net, const char *host_addr);
193 
194 /**
195  * gether_get_host_addr - get an ethernet-over-usb link host address
196  * @net: device representing this link
197  * @host_addr: place to store eth address of the host
198  * @len: length of the @host_addr buffer
199  *
200  * This gets the host-side Ethernet address of this ethernet-over-usb link.
201  * Returns zero on success, else negative errno.
202  */
203 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
204 
205 /**
206  * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
207  * @net: device representing this link
208  * @host_addr: place to store eth address of the host
209  * @len: length of the @host_addr buffer
210  *
211  * This gets the CDC formatted host-side Ethernet address of this
212  * ethernet-over-usb link.
213  * Returns zero on success, else negative errno.
214  */
215 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
216 
217 /**
218  * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
219  * @net: device representing this link
220  * @host_mac: place to store the eth address of the host
221  *
222  * This gets the binary formatted host-side Ethernet address of this
223  * ethernet-over-usb link.
224  */
225 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
226 
227 /**
228  * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
229  * @net: device representing this link
230  * @qmult: queue multiplier
231  *
232  * This sets the queue length multiplier of this ethernet-over-usb link.
233  * For higher speeds use longer queues.
234  */
235 void gether_set_qmult(struct net_device *net, unsigned qmult);
236 
237 /**
238  * gether_get_qmult - get an ethernet-over-usb link multiplier
239  * @net: device representing this link
240  *
241  * This gets the queue length multiplier of this ethernet-over-usb link.
242  */
243 unsigned gether_get_qmult(struct net_device *net);
244 
245 /**
246  * gether_get_ifname - get an ethernet-over-usb link interface name
247  * @net: device representing this link
248  * @name: place to store the interface name
249  * @len: length of the @name buffer
250  *
251  * This gets the interface name of this ethernet-over-usb link.
252  * Returns zero on success, else negative errno.
253  */
254 int gether_get_ifname(struct net_device *net, char *name, int len);
255 
256 void gether_cleanup(struct eth_dev *dev);
257 
258 /* connect/disconnect is handled by individual functions */
259 struct net_device *gether_connect(struct gether *);
260 void gether_disconnect(struct gether *);
261 
262 /* Some controllers can't support CDC Ethernet (ECM) ... */
can_support_ecm(struct usb_gadget * gadget)263 static inline bool can_support_ecm(struct usb_gadget *gadget)
264 {
265 	if (!gadget_supports_altsettings(gadget))
266 		return false;
267 
268 	/* Everything else is *presumably* fine ... but this is a bit
269 	 * chancy, so be **CERTAIN** there are no hardware issues with
270 	 * your controller.  Add it above if it can't handle CDC.
271 	 */
272 	return true;
273 }
274 
275 #endif /* __U_ETHER_H */
276