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
39struct 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 */
52struct 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 */
91struct 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 */
108static 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, netname: "usb");
113}
114
115/*
116 * variant of gether_setup_default that allows customizing
117 * network device name
118 */
119struct 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 */
128int 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 */
139static inline struct net_device *gether_setup_default(void)
140{
141 return gether_setup_name_default(netname: "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 */
151void 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 */
162int 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 */
173int 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 */
184int 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 */
195int 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 */
207int 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 */
217void 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 */
227void 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 */
235unsigned 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 */
246int 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 */
258int gether_set_ifname(struct net_device *net, const char *name, int len);
259
260void gether_cleanup(struct eth_dev *dev);
261
262void gether_suspend(struct gether *link);
263void gether_resume(struct gether *link);
264
265/* connect/disconnect is handled by individual functions */
266struct net_device *gether_connect(struct gether *);
267void gether_disconnect(struct gether *);
268
269/* Some controllers can't support CDC Ethernet (ECM) ... */
270static inline bool can_support_ecm(struct usb_gadget *gadget)
271{
272 if (!gadget_is_altset_supported(g: 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 */
283static 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

source code of linux/drivers/usb/gadget/function/u_ether.h