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