drivers/usb/gadget/function/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
  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 */