/*
* u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
*
* Copyright (C) 2003-2005,2008 David Brownell
* Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
* Copyright (C) 2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/* #define VERBOSE_DEBUG */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include "u_ether.h"
/*
* This component encapsulates the Ethernet link glue needed to provide
* one (!) network link through the USB gadget stack, normally "usb0".
*
* The control and data models are handled by the function driver which
* connects to this code; such as CDC Ethernet (ECM or EEM),
* "CDC Subset", or RNDIS. That includes all descriptor and endpoint
* management.
*
* Link level addressing is handled by this component using module
* parameters; if no such parameters are provided, random link level
* addresses are used. Each end of the link uses one address. The
* host end address is exported in various ways, and is often recorded
* in configuration databases.
*
* The driver which assembles each configuration using such a link is
* responsible for ensuring that each configuration includes at most one
* instance of is network link. (The network layer provides ways for
* this single "physical" link to be used by multiple virtual links.)
*/
#define UETH__VERSION "29-May-2008"
/* Experiments show that both Linux and Windows hosts allow up to 16k
* frame sizes. Set the max size to 15k+52 to prevent allocating 32k
* blocks and still have efficient handling. */
#define GETHER_MAX_ETH_FRAME_LEN 15412
struct eth_dev {
/* lock is held while accessing port_usb
*/
spinlock_t lock;
struct gether *port_usb;
struct net_device *net;
struct usb_gadget *gadget;
spinlock_t req_lock; /* guard {rx,tx}_reqs */
struct list_head tx_reqs, rx_reqs;
atomic_t tx_qlen;
struct sk_buff_head rx_frames;
unsigned qmult;
unsigned header_len;
struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
int (*unwrap)(struct gether *,
struct sk_buff *skb,
struct sk_buff_head *list);
struct work_struct work;
unsigned long todo;
#define WORK_RX_MEMORY 0
bool zlp;
u8 host_mac[ETH_ALEN];
u8 dev_mac[ETH_ALEN];
};
/*-------------------------------------------------------------------------*/
#define RX_EXTRA 20 /* bytes guarding against rx overflows */
#define DEFAULT_QLEN 2 /* double buffering by default */
/* for dual-speed hardware, use deeper queues at high/super speed */
static inline int qlen(struct usb_gadget *gadget, unsigned qmult)
{
if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
gadget->speed == USB_SPEED_SUPER))
return qmult * DEFAULT_QLEN;
else
return DEFAULT_QLEN;
}
/*-------------------------------------------------------------------------*/
/* REVISIT there must be a better way than having two sets
* of debug calls ...
*/
#undef DBG
#undef VDBG
#undef ERROR
#undef INFO
#define xprintk(d, level, fmt, args...) \
printk(level "%s: " fmt , (d)->net->name , ## args)
#ifdef DEBUG
#undef DEBUG
#define DBG(dev, fmt, args...) \
xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#ifdef VERBOSE_DEBUG
#define VDBG DBG
#else
#define VDBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#define ERROR(dev, fmt, args...) \
xprintk(dev , KERN_ERR , fmt , ## args)
#define INFO(dev, fmt, args...) \
xprintk(dev , KERN_INFO , fmt , ## args)
/*-------------------------------------------------------------------------*/
/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
static int ueth_change_mtu(struct net_device *net, int new_mtu)
{
if (new_mtu <= ETH_HLEN || new_mtu > GETHER_MAX_ETH_FRAME_LEN)
return -ERANGE;
net->mtu = new_mtu;
return 0;
}
static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
{
struct eth_dev *dev = netdev_priv(net);
strlcpy(p->driver, "g_ether", sizeof(p->driver));
strlcpy(p->version, UETH__VERSION, sizeof(p->version));
strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
strlcpy(p->bus_info, dev_name(&dev->gadget->dev),