xref: /linux/drivers/usb/gadget/function/u_ether.h (revision b17ef04bf3a4346d66404454d6a646343ddc9749)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * u_ether.h -- interface to USB gadget "ethernet link" utilities
4  *
5  * Copyright (C) 2003-2005,2008 David Brownell
6  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
7  * Copyright (C) 2008 Nokia Corporation
8  */
9 
10 #ifndef __U_ETHER_H
11 #define __U_ETHER_H
12 
13 #include <linux/err.h>
14 #include <linux/if_ether.h>
15 #include <linux/usb/composite.h>
16 #include <linux/usb/cdc.h>
17 #include <linux/netdevice.h>
18 
19 #define QMULT_DEFAULT 5
20 
21 /*
22  * dev_addr: initial value
23  * changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx"
24  * host_addr: this address is invisible to ifconfig
25  */
26 #define USB_ETHERNET_MODULE_PARAMETERS() \
27 	static unsigned qmult = QMULT_DEFAULT;				\
28 	module_param(qmult, uint, S_IRUGO|S_IWUSR);			\
29 	MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");\
30 									\
31 	static char *dev_addr;						\
32 	module_param(dev_addr, charp, S_IRUGO);				\
33 	MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");		\
34 									\
35 	static char *host_addr;						\
36 	module_param(host_addr, charp, S_IRUGO);			\
37 	MODULE_PARM_DESC(host_addr, "Host Ethernet Address")
38 
39 struct eth_dev;
40 
41 /*
42  * This represents the USB side of an "ethernet" link, managed by a USB
43  * function which provides control and (maybe) framing.  Two functions
44  * in different configurations could share the same ethernet link/netdev,
45  * using different host interaction models.
46  *
47  * There is a current limitation that only one instance of this link may
48  * be present in any given configuration.  When that's a problem, network
49  * layer facilities can be used to package multiple logical links on this
50  * single "physical" one.
51  */
52 struct gether {
53 	struct usb_function		func;
54 
55 	/* updated by gether_{connect,disconnect} */
56 	struct eth_dev			*ioport;
57 
58 	/* endpoints handle full and/or high speeds */
59 	struct usb_ep			*in_ep;
60 	struct usb_ep			*out_ep;
61 
62 	bool				is_zlp_ok;
63 
64 	u16				cdc_filter;
65 
66 	/* hooks for added framing, as needed for RNDIS and EEM. */
67 	u32				header_len;
68 	/* NCM requires fixed size bundles */
69 	bool				is_fixed;
70 	u32				fixed_out_len;
71 	u32				fixed_in_len;
72 	bool				supports_multi_frame;
73 	struct sk_buff			*(*wrap)(struct gether *port,
74 						struct sk_buff *skb);
75 	int				(*unwrap)(struct gether *port,
76 						struct sk_buff *skb,
77 						struct sk_buff_head *list);
78 
79 	/* called on network open/close */
80 	void				(*open)(struct gether *);
81 	void				(*close)(struct gether *);
82 	bool				is_suspend;
83 };
84 
85 #define	DEFAULT_FILTER	(USB_CDC_PACKET_TYPE_BROADCAST \
86 			|USB_CDC_PACKET_TYPE_ALL_MULTICAST \
87 			|USB_CDC_PACKET_TYPE_PROMISCUOUS \
88 			|USB_CDC_PACKET_TYPE_DIRECTED)
89 
90 /* variant of gether_setup that allows customizing network device name */
91 struct eth_dev *gether_setup_name(struct usb_gadget *g,
92 		const char *dev_addr, const char *host_addr,
93 		u8 ethaddr[ETH_ALEN], unsigned qmult, const char *netname);
94 
95 /* netdev setup/teardown as directed by the gadget driver */
96 /* gether_setup - initialize one ethernet-over-usb link
97  * @g: gadget to associated with these links
98  * @ethaddr: NULL, or a buffer in which the ethernet address of the
99  *	host side of the link is recorded
100  * Context: may sleep
101  *
102  * This sets up the single network link that may be exported by a
103  * gadget driver using this framework.  The link layer addresses are
104  * set up using module parameters.
105  *
106  * Returns a eth_dev pointer on success, or an ERR_PTR on failure
107  */
108 static inline struct eth_dev *gether_setup(struct usb_gadget *g,
109 		const char *dev_addr, const char *host_addr,
110 		u8 ethaddr[ETH_ALEN], unsigned qmult)
111 {
112 	return gether_setup_name(g, dev_addr, host_addr, ethaddr, qmult, "usb");
113 }
114 
115 /*
116  * variant of gether_setup_default that allows customizing
117  * network device name
118  */
119 struct net_device *gether_setup_name_default(const char *netname);
120 
121 /*
122  * gether_register_netdev - register the net device
123  * @net: net device to register
124  *
125  * Registers the net device associated with this ethernet-over-usb link
126  *
127  */
128 int gether_register_netdev(struct net_device *net);
129 
130 /* gether_setup_default - initialize one ethernet-over-usb link
131  * Context: may sleep
132  *
133  * This sets up the single network link that may be exported by a
134  * gadget driver using this framework.  The link layer addresses
135  * are set to random values.
136  *
137  * Returns negative errno, or zero on success
138  */
139 static inline struct net_device *gether_setup_default(void)
140 {
141 	return gether_setup_name_default("usb");
142 }
143 
144 /**
145  * gether_set_gadget - initialize one ethernet-over-usb link with a gadget
146  * @net: device representing this link
147  * @g: the gadget to initialize with
148  *
149  * This associates one ethernet-over-usb link with a gadget.
150  */
151 void gether_set_gadget(struct net_device *net, struct usb_gadget *g);
152 
153 /**
154  * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
155  * @net: device representing this link
156  * @dev_addr: eth address of this device
157  *
158  * This sets the device-side Ethernet address of this ethernet-over-usb link
159  * if dev_addr is correct.
160  * Returns negative errno if the new address is incorrect.
161  */
162 int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
163 
164 /**
165  * gether_get_dev_addr - get an ethernet-over-usb link eth address
166  * @net: device representing this link
167  * @dev_addr: place to store device's eth address
168  * @len: length of the @dev_addr buffer
169  *
170  * This gets the device-side Ethernet address of this ethernet-over-usb link.
171  * Returns zero on success, else negative errno.
172  */
173 int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
174 
175 /**
176  * gether_set_host_addr - initialize an ethernet-over-usb link with host address
177  * @net: device representing this link
178  * @host_addr: eth address of the host
179  *
180  * This sets the host-side Ethernet address of this ethernet-over-usb link
181  * if host_addr is correct.
182  * Returns negative errno if the new address is incorrect.
183  */
184 int gether_set_host_addr(struct net_device *net, const char *host_addr);
185 
186 /**
187  * gether_get_host_addr - get an ethernet-over-usb link host address
188  * @net: device representing this link
189  * @host_addr: place to store eth address of the host
190  * @len: length of the @host_addr buffer
191  *
192  * This gets the host-side Ethernet address of this ethernet-over-usb link.
193  * Returns zero on success, else negative errno.
194  */
195 int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
196 
197 /**
198  * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
199  * @net: device representing this link
200  * @host_addr: place to store eth address of the host
201  * @len: length of the @host_addr buffer
202  *
203  * This gets the CDC formatted host-side Ethernet address of this
204  * ethernet-over-usb link.
205  * Returns zero on success, else negative errno.
206  */
207 int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
208 
209 /**
210  * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
211  * @net: device representing this link
212  * @host_mac: place to store the eth address of the host
213  *
214  * This gets the binary formatted host-side Ethernet address of this
215  * ethernet-over-usb link.
216  */
217 void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
218 
219 /**
220  * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
221  * @net: device representing this link
222  * @qmult: queue multiplier
223  *
224  * This sets the queue length multiplier of this ethernet-over-usb link.
225  * For higher speeds use longer queues.
226  */
227 void gether_set_qmult(struct net_device *net, unsigned qmult);
228 
229 /**
230  * gether_get_qmult - get an ethernet-over-usb link multiplier
231  * @net: device representing this link
232  *
233  * This gets the queue length multiplier of this ethernet-over-usb link.
234  */
235 unsigned gether_get_qmult(struct net_device *net);
236 
237 /**
238  * gether_get_ifname - get an ethernet-over-usb link interface name
239  * @net: device representing this link
240  * @name: place to store the interface name
241  * @len: length of the @name buffer
242  *
243  * This gets the interface name of this ethernet-over-usb link.
244  * Returns zero on success, else negative errno.
245  */
246 int gether_get_ifname(struct net_device *net, char *name, int len);
247 
248 /**
249  * gether_set_ifname - set an ethernet-over-usb link interface name
250  * @net: device representing this link
251  * @name: new interface name
252  * @len: length of @name
253  *
254  * This sets the interface name of this ethernet-over-usb link.
255  * A single terminating newline, if any, is ignored.
256  * Returns zero on success, else negative errno.
257  */
258 int gether_set_ifname(struct net_device *net, const char *name, int len);
259 
260 void gether_cleanup(struct eth_dev *dev);
261 
262 void gether_suspend(struct gether *link);
263 void gether_resume(struct gether *link);
264 
265 /* connect/disconnect is handled by individual functions */
266 struct net_device *gether_connect(struct gether *);
267 void gether_disconnect(struct gether *);
268 
269 /* Some controllers can't support CDC Ethernet (ECM) ... */
270 static inline bool can_support_ecm(struct usb_gadget *gadget)
271 {
272 	if (!gadget_is_altset_supported(gadget))
273 		return false;
274 
275 	/* Everything else is *presumably* fine ... but this is a bit
276 	 * chancy, so be **CERTAIN** there are no hardware issues with
277 	 * your controller.  Add it above if it can't handle CDC.
278 	 */
279 	return true;
280 }
281 
282 /* peak (theoretical) bulk transfer rate in bits-per-second */
283 static inline unsigned int gether_bitrate(struct usb_gadget *g)
284 {
285 	if (g->speed >= USB_SPEED_SUPER_PLUS)
286 		return 4250000000U;
287 	if (g->speed == USB_SPEED_SUPER)
288 		return 3750000000U;
289 	else if (g->speed == USB_SPEED_HIGH)
290 		return 13 * 512 * 8 * 1000 * 8;
291 	else
292 		return 19 * 64 * 1 * 1000 * 8;
293 }
294 
295 #endif /* __U_ETHER_H */
296