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