u_ether.h

  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, "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("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_attach_gadget - Reparent net_device to the gadget device.
155 * @net: The network device to reparent.
156 * @g: The target USB gadget device to parent to.
157 *
158 * This function moves the network device to be a child of the USB gadget
159 * device in the device hierarchy. This is typically done when the function
160 * is bound to a configuration.
161 *
162 * Returns 0 on success, or a negative error code on failure.
163 */
164int gether_attach_gadget(struct net_device *net, struct usb_gadget *g);
165
166/**
167 * gether_detach_gadget - Detach net_device from its gadget parent.
168 * @net: The network device to detach.
169 *
170 * This function moves the network device to be a child of the virtual
171 * devices parent, effectively detaching it from the USB gadget device
172 * hierarchy. This is typically done when the function is unbound
173 * from a configuration but the instance is not yet freed.
174 */
175void gether_detach_gadget(struct net_device *net);
176
177DEFINE_FREE(detach_gadget, struct net_device *, if (_T) gether_detach_gadget(_T))
178
179/**
180 * gether_set_dev_addr - initialize an ethernet-over-usb link with eth address
181 * @net: device representing this link
182 * @dev_addr: eth address of this device
183 *
184 * This sets the device-side Ethernet address of this ethernet-over-usb link
185 * if dev_addr is correct.
186 * Returns negative errno if the new address is incorrect.
187 */
188int gether_set_dev_addr(struct net_device *net, const char *dev_addr);
189
190/**
191 * gether_get_dev_addr - get an ethernet-over-usb link eth address
192 * @net: device representing this link
193 * @dev_addr: place to store device's eth address
194 * @len: length of the @dev_addr buffer
195 *
196 * This gets the device-side Ethernet address of this ethernet-over-usb link.
197 * Returns zero on success, else negative errno.
198 */
199int gether_get_dev_addr(struct net_device *net, char *dev_addr, int len);
200
201/**
202 * gether_set_host_addr - initialize an ethernet-over-usb link with host address
203 * @net: device representing this link
204 * @host_addr: eth address of the host
205 *
206 * This sets the host-side Ethernet address of this ethernet-over-usb link
207 * if host_addr is correct.
208 * Returns negative errno if the new address is incorrect.
209 */
210int gether_set_host_addr(struct net_device *net, const char *host_addr);
211
212/**
213 * gether_get_host_addr - get an ethernet-over-usb link host address
214 * @net: device representing this link
215 * @host_addr: place to store eth address of the host
216 * @len: length of the @host_addr buffer
217 *
218 * This gets the host-side Ethernet address of this ethernet-over-usb link.
219 * Returns zero on success, else negative errno.
220 */
221int gether_get_host_addr(struct net_device *net, char *host_addr, int len);
222
223/**
224 * gether_get_host_addr_cdc - get an ethernet-over-usb link host address
225 * @net: device representing this link
226 * @host_addr: place to store eth address of the host
227 * @len: length of the @host_addr buffer
228 *
229 * This gets the CDC formatted host-side Ethernet address of this
230 * ethernet-over-usb link.
231 * Returns zero on success, else negative errno.
232 */
233int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len);
234
235/**
236 * gether_get_host_addr_u8 - get an ethernet-over-usb link host address
237 * @net: device representing this link
238 * @host_mac: place to store the eth address of the host
239 *
240 * This gets the binary formatted host-side Ethernet address of this
241 * ethernet-over-usb link.
242 */
243void gether_get_host_addr_u8(struct net_device *net, u8 host_mac[ETH_ALEN]);
244
245/**
246 * gether_set_qmult - initialize an ethernet-over-usb link with a multiplier
247 * @net: device representing this link
248 * @qmult: queue multiplier
249 *
250 * This sets the queue length multiplier of this ethernet-over-usb link.
251 * For higher speeds use longer queues.
252 */
253void gether_set_qmult(struct net_device *net, unsigned qmult);
254
255/**
256 * gether_get_qmult - get an ethernet-over-usb link multiplier
257 * @net: device representing this link
258 *
259 * This gets the queue length multiplier of this ethernet-over-usb link.
260 */
261unsigned gether_get_qmult(struct net_device *net);
262
263/**
264 * gether_get_ifname - get an ethernet-over-usb link interface name
265 * @net: device representing this link
266 * @name: place to store the interface name
267 * @len: length of the @name buffer
268 *
269 * This gets the interface name of this ethernet-over-usb link.
270 * Returns zero on success, else negative errno.
271 */
272int gether_get_ifname(struct net_device *net, char *name, int len);
273
274/**
275 * gether_set_ifname - set an ethernet-over-usb link interface name
276 * @net: device representing this link
277 * @name: new interface name
278 * @len: length of @name
279 *
280 * This sets the interface name of this ethernet-over-usb link.
281 * A single terminating newline, if any, is ignored.
282 * Returns zero on success, else negative errno.
283 */
284int gether_set_ifname(struct net_device *net, const char *name, int len);
285
286void gether_cleanup(struct eth_dev *dev);
287
288void gether_suspend(struct gether *link);
289void gether_resume(struct gether *link);
290
291/* connect/disconnect is handled by individual functions */
292struct net_device *gether_connect(struct gether *);
293void gether_disconnect(struct gether *);
294
295/* Some controllers can't support CDC Ethernet (ECM) ... */
296static inline bool can_support_ecm(struct usb_gadget *gadget)
297{
298	if (!gadget_is_altset_supported(gadget))
299		return false;
300
301	/* Everything else is *presumably* fine ... but this is a bit
302	 * chancy, so be **CERTAIN** there are no hardware issues with
303	 * your controller.  Add it above if it can't handle CDC.
304	 */
305	return true;
306}
307
308/* peak (theoretical) bulk transfer rate in bits-per-second */
309static inline unsigned int gether_bitrate(struct usb_gadget *g)
310{
311	if (g->speed >= USB_SPEED_SUPER_PLUS)
312		return 4250000000U;
313	if (g->speed == USB_SPEED_SUPER)
314		return 3750000000U;
315	else if (g->speed == USB_SPEED_HIGH)
316		return 13 * 512 * 8 * 1000 * 8;
317	else
318		return 19 * 64 * 1 * 1000 * 8;
319}
320
321#endif /* __U_ETHER_H */