diff options
Diffstat (limited to 'drivers/usb/gadget/u_ether.c')
| -rw-r--r-- | drivers/usb/gadget/u_ether.c | 967 |
1 files changed, 967 insertions, 0 deletions
diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c new file mode 100644 index 00000000000..5458f43a866 --- /dev/null +++ b/drivers/usb/gadget/u_ether.c @@ -0,0 +1,967 @@ +/* + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* #define VERBOSE_DEBUG */ + +#include <linux/kernel.h> +#include <linux/utsname.h> +#include <linux/device.h> +#include <linux/ctype.h> +#include <linux/etherdevice.h> +#include <linux/ethtool.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, "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 DRIVER_VERSION "29-May-2008" + +struct eth_dev { + /* lock is held while accessing port_usb + * or updating its backlink port_usb->ioport + */ + 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; + + unsigned header_len; + struct sk_buff *(*wrap)(struct sk_buff *skb); + int (*unwrap)(struct sk_buff *skb); + + struct work_struct work; + + unsigned long todo; +#define WORK_RX_MEMORY 0 + + bool zlp; + u8 host_mac[ETH_ALEN]; +}; + +/*-------------------------------------------------------------------------*/ + +#define RX_EXTRA 20 /* bytes guarding against rx overflows */ + +#define DEFAULT_QLEN 2 /* double buffering by default */ + + +#ifdef CONFIG_USB_GADGET_DUALSPEED + +static unsigned qmult = 5; +module_param(qmult, uint, S_IRUGO|S_IWUSR); +MODULE_PARM_DESC(qmult, "queue length multiplier at high speed"); + +#else /* full speed (low speed doesn't do bulk) */ +#define qmult 1 +#endif + +/* for dual-speed hardware, use deeper queues at highspeed */ +static inline int qlen(struct usb_gadget *gadget) +{ + if (gadget_is_dualspeed(gadget) && gadget->speed == USB_SPEED_HIGH) + 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 WARN +#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 WARN(dev, fmt, args...) \ + xprintk(dev , KERN_WARNING , fmt , ## args) +#define INFO(dev, fmt, args...) \ + xprintk(dev , KERN_INFO , fmt , ## args) + +/*-------------------------------------------------------------------------*/ + +/* NETWORK DRIVER HOOKUP (to the layer above this driver) */ + +static int eth_change_mtu(struct net_device *net, int new_mtu) +{ + struct eth_dev *dev = netdev_priv(net); + unsigned long flags; + int status = 0; + + /* don't change MTU on "live" link (peer won't know) */ + spin_lock_irqsave(&dev->lock, flags); + if (dev->port_usb) + status = -EBUSY; + else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN) + status = -ERANGE; + else + net->mtu = new_mtu; + spin_unlock_irqrestore(&dev->lock, flags); + + return status; +} + +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, DRIVER_VERSION, sizeof p->version); + strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version); + strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info); +} + +static u32 eth_get_link(struct net_device *net) +{ + struct eth_dev *dev = netdev_priv(net); + return dev->gadget->speed != USB_SPEED_UNKNOWN; +} + +/* REVISIT can also support: + * - WOL (by tracking suspends and issuing remote wakeup) + * - msglevel (implies updated messaging) + * - ... probably more ethtool ops + */ + +static struct ethtool_ops ops = { + .get_drvinfo = eth_get_drvinfo, + .get_link = eth_get_link +}; + +static void defer_kevent(struct eth_dev *dev, int flag) +{ + if (test_and_set_bit(flag, &dev->todo)) + return; + if (!schedule_work(&dev->work)) + ERROR(dev, "kevent %d may have been dropped\n", flag); + else + DBG(dev, "kevent %d scheduled\n", flag); +} + +static void rx_complete(struct usb_ep *ep, struct usb_request *req); + +static int +rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) +{ + struct sk_buff *skb; + int retval = -ENOMEM; + size_t size = 0; + struct usb_ep *out; + unsigned long flags; + + spin_lock_irqsave(&dev->lock, flags); + if (dev->port_usb) + out = dev->port_usb->out_ep; + else + out = NULL; + spin_unlock_irqrestore(&dev->lock, flags); + + if (!out) + return -ENOTCONN; + + + /* Padding up to RX_EXTRA handles minor disagreements with host. + * Normally we use the USB "terminate on short read" convention; + * so allow up to (N*maxpacket), since that memory is normally + * already allocated. Some hardware doesn't deal well with short + * reads (e.g. DMA must be N*maxpacket), so for now don't trim a + * byte off the end (to force hardware errors on overflow). + * + * RNDIS uses internal framing, and explicitly allows senders to + * pad to end-of-packet. That's potentially nice for speed, but + * means receivers can't recover lost synch on their own (because + * new packets don't only start after a short RX). + */ + size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA; + size += dev->port_usb->header_len; + size += out->maxpacket - 1; + size -= size % out->maxpacket; + + skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags); + if (skb == NULL) { + DBG(dev, "no rx skb\n"); + goto enomem; + } + + /* Some platforms perform better when IP packets are aligned, + * but on at least one, checksumming fails otherwise. Note: + * RNDIS headers involve variable numbers of LE32 values. + */ + skb_reserve(skb, NET_IP_ALIGN); + + req->buf = skb->data; + req->length = size; + req->complete = rx_complete; + req->context = skb; + + retval = usb_ep_queue(out, req, gfp_flags); + if (retval == -ENOMEM) +enomem: + defer_kevent(dev, WORK_RX_MEMORY); + if (retval) { + DBG(dev, "rx submit --> %d\n", retval); + if (skb) + dev_kfree_skb_any(skb); + spin_lock_irqsave(&dev->req_lock, flags); + list_add(&req->list, &dev->rx_reqs); + spin_unlock_irqrestore(&dev->req_lock, flags); + } + return retval; +} + +static void rx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct sk_buff *skb = req->context; + struct eth_dev *dev = ep->driver_data; + int status = req->status; + + switch (status) { + + /* normal completion */ + case 0: + skb_put(skb, req->actual); + if (dev->unwrap) + status = dev->unwrap(skb); + if (status < 0 + || ETH_HLEN > skb->len + || skb->len > ETH_FRAME_LEN) { + dev->net->stats.rx_errors++; + dev->net->stats.rx_length_errors++; + DBG(dev, "rx length %d\n", skb->len); + break; + } + + skb->protocol = eth_type_trans(skb, dev->net); + dev->net->stats.rx_packets++; + dev->net->stats.rx_bytes += skb->len; + + /* no buffer copies needed, unless hardware can't + * use skb buffers. + */ + status = netif_rx(skb); + skb = NULL; + break; + + /* software-driven interface shutdown */ + case -ECONNRESET: /* unlink */ + case -ESHUTDOWN: /* disconnect etc */ + VDBG(dev, "rx shutdown, code %d\n", status); + goto quiesce; + + /* for hardware automagic (such as pxa) */ + case -ECONNABORTED: /* endpoint reset */ + DBG(dev, "rx %s reset\n", ep->name); + defer_kevent(dev, WORK_RX_MEMORY); +quiesce: + dev_kfree_skb_any(skb); + goto clean; + + /* data overrun */ + case -EOVERFLOW: + dev->net->stats.rx_over_errors++; + /* FALLTHROUGH */ + + default: + dev->net->stats.rx_errors++; + DBG(dev, "rx status %d\n", status); + break; + } + + if (skb) + dev_kfree_skb_any(skb); + if (!netif_running(dev->net)) { +clean: + spin_lock(&dev->req_lock); + list_add(&req->list, &dev->rx_reqs); + spin_unlock(&dev->req_lock); + req = NULL; + } + if (req) + rx_submit(dev, req, GFP_ATOMIC); +} + +static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n) +{ + unsigned i; + struct usb_request *req; + + if (!n) + return -ENOMEM; + + /* queue/recycle up to N requests */ + i = n; + list_for_each_entry(req, list, list) { + if (i-- == 0) + goto extra; + } + while (i--) { + req = usb_ep_alloc_request(ep, GFP_ATOMIC); + if (!req) + return list_empty(list) ? -ENOMEM : 0; + list_add(&req->list, list); + } + return 0; + +extra: + /* free extras */ + for (;;) { + struct list_head *next; + + next = req->list.next; + list_del(&req->list); + usb_ep_free_request(ep, req); + + if (next == list) + break; + + req = container_of(next, struct usb_request, list); + } + return 0; +} + +static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n) +{ + int status; + + spin_lock(&dev->req_lock); + status = prealloc(&dev->tx_reqs, link->in_ep, n); + if (status < 0) + goto fail; + status = prealloc(&dev->rx_reqs, link->out_ep, n); + if (status < 0) + goto fail; + goto done; +fail: + DBG(dev, "can't alloc requests\n"); +done: + spin_unlock(&dev->req_lock); + return status; +} + +static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags) +{ + struct usb_request *req; + unsigned long flags; + + /* fill unused rxq slots with some skb */ + spin_lock_irqsave(&dev->req_lock, flags); + while (!list_empty(&dev->rx_reqs)) { + req = container_of(dev->rx_reqs.next, + struct usb_request, list); + list_del_init(&req->list); + spin_unlock_irqrestore(&dev->req_lock, flags); + + if (rx_submit(dev, req, gfp_flags) < 0) { + defer_kevent(dev, WORK_RX_MEMORY); + return; + } + + spin_lock_irqsave(&dev->req_lock, flags); + } + spin_unlock_irqrestore(&dev->req_lock, flags); +} + +static void eth_work(struct work_struct *work) +{ + struct eth_dev *dev = container_of(work, struct eth_dev, work); + + if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) { + if (netif_running(dev->net)) + rx_fill(dev, GFP_KERNEL); + } + + if (dev->todo) + DBG(dev, "work done, flags = 0x%lx\n", dev->todo); +} + +static void tx_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct sk_buff *skb = req->context; + struct eth_dev *dev = ep->driver_data; + + switch (req->status) { + default: + dev->net->stats.tx_errors++; + VDBG(dev, "tx err %d\n", req->status); + /* FALLTHROUGH */ + case -ECONNRESET: /* unlink */ + case -ESHUTDOWN: /* disconnect etc */ + break; + case 0: + dev->net->stats.tx_bytes += skb->len; + } + dev->net->stats.tx_packets++; + + spin_lock(&dev->req_lock); + list_add(&req->list, &dev->tx_reqs); + spin_unlock(&dev->req_lock); + dev_kfree_skb_any(skb); + + atomic_dec(&dev->tx_qlen); + if (netif_carrier_ok(dev->net)) + netif_wake_queue(dev->net); +} + +static inline int is_promisc(u16 cdc_filter) +{ + return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS; +} + +static int eth_start_xmit(struct sk_buff *skb, struct net_device *net) +{ + struct eth_dev *dev = netdev_priv(net); + int length = skb->len; + int retval; + struct usb_request *req = NULL; + unsigned long flags; + struct usb_ep *in; + u16 cdc_filter; + + spin_lock_irqsave(&dev->lock, flags); + if (dev->port_usb) { + in = dev->port_usb->in_ep; + cdc_filter = dev->port_usb->cdc_filter; + } else { + in = NULL; + cdc_filter = 0; + } + spin_unlock_irqrestore(&dev->lock, flags); + + if (!in) { + dev_kfree_skb_any(skb); + return 0; + } + + /* apply outgoing CDC or RNDIS filters */ + if (!is_promisc(cdc_filter)) { + u8 *dest = skb->data; + + if (is_multicast_ether_addr(dest)) { + u16 type; + + /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host + * SET_ETHERNET_MULTICAST_FILTERS requests + */ + if (is_broadcast_ether_addr(dest)) + type = USB_CDC_PACKET_TYPE_BROADCAST; + else + type = USB_CDC_PACKET_TYPE_ALL_MULTICAST; + if (!(cdc_filter & type)) { + dev_kfree_skb_any(skb); + return 0; + } + } + /* ignores USB_CDC_PACKET_TYPE_DIRECTED */ + } + + spin_lock_irqsave(&dev->req_lock, flags); + /* + * this freelist can be empty if an interrupt triggered disconnect() + * and reconfigured the gadget (shutting down this queue) after the + * network stack decided to xmit but before we got the spinlock. + */ + if (list_empty(&dev->tx_reqs)) { + spin_unlock_irqrestore(&dev->req_lock, flags); + return 1; + } + + req = container_of(dev->tx_reqs.next, struct usb_request, list); + list_del(&req->list); + + /* temporarily stop TX queue when the freelist empties */ + if (list_empty(&dev->tx_reqs)) + netif_stop_queue(net); + spin_unlock_irqrestore(&dev->req_lock, flags); + + /* no buffer copies needed, unless the network stack did it + * or the hardware can't use skb buffers. + * or there's not enough space for extra headers we need + */ + if (dev->wrap) { + struct sk_buff *skb_new; + + skb_new = dev->wrap(skb); + if (!skb_new) + goto drop; + + dev_kfree_skb_any(skb); + skb = skb_new; + length = skb->len; + } + req->buf = skb->data; + req->context = skb; + req->complete = tx_complete; + + /* use zlp framing on tx for strict CDC-Ether conformance, + * though any robust network rx path ignores extra padding. + * and some hardware doesn't like to write zlps. + */ + req->zero = 1; + if (!dev->zlp && (length % in->maxpacket) == 0) + length++; + + req->length = length; + + /* throttle highspeed IRQ rate back slightly */ + if (gadget_is_dualspeed(dev->gadget)) + req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH) + ? ((atomic_read(&dev->tx_qlen) % qmult) != 0) + : 0; + + retval = usb_ep_queue(in, req, GFP_ATOMIC); + switch (retval) { + default: + DBG(dev, "tx queue err %d\n", retval); + break; + case 0: + net->trans_start = jiffies; + atomic_inc(&dev->tx_qlen); + } + + if (retval) { +drop: + dev->net->stats.tx_dropped++; + dev_kfree_skb_any(skb); + spin_lock_irqsave(&dev->req_lock, flags); + if (list_empty(&dev->tx_reqs)) + netif_start_queue(net); + list_add(&req->list, &dev->tx_reqs); + spin_unlock_irqrestore(&dev->req_lock, flags); + } + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static void eth_start(struct eth_dev *dev, gfp_t gfp_flags) +{ + DBG(dev, "%s\n", __func__); + + /* fill the rx queue */ + rx_fill(dev, gfp_flags); + + /* and open the tx floodgates */ + atomic_set(&dev->tx_qlen, 0); + netif_wake_queue(dev->net); +} + +static int eth_open(struct net_device *net) +{ + struct eth_dev *dev = netdev_priv(net); + struct gether *link; + + DBG(dev, "%s\n", __func__); + if (netif_carrier_ok(dev->net)) + eth_start(dev, GFP_KERNEL); + + spin_lock_irq(&dev->lock); + link = dev->port_usb; + if (link && link->open) + link->open(link); + spin_unlock_irq(&dev->lock); + + return 0; +} + +static int eth_stop(struct net_device *net) +{ + struct eth_dev *dev = netdev_priv(net); + unsigned long flags; + + VDBG(dev, "%s\n", __func__); + netif_stop_queue(net); + + DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n", + dev->net->stats.rx_packets, dev->net->stats.tx_packets, + dev->net->stats.rx_errors, dev->net->stats.tx_errors + ); + + /* ensure there are no more active requests */ + spin_lock_irqsave(&dev->lock, flags); + if (dev->port_usb) { + struct gether *link = dev->port_usb; + + if (link->close) + link->close(link); + + /* NOTE: we have no abort-queue primitive we could use + * to cancel all pending I/O. Instead, we disable then + * reenable the endpoints ... this idiom may leave toggle + * wrong, but that's a self-correcting error. + * + * REVISIT: we *COULD* just let the transfers complete at + * their own pace; the network stack can handle old packets. + * For the moment we leave this here, since it works. + */ + usb_ep_disable(link->in_ep); + usb_ep_disable(link->out_ep); + if (netif_carrier_ok(net)) { + DBG(dev, "host still using in/out endpoints\n"); + usb_ep_enable(link->in_ep, link->in); + usb_ep_enable(link->out_ep, link->out); + } + } + spin_unlock_irqrestore(&dev->lock, flags); + + return 0; +} + +/*-------------------------------------------------------------------------*/ + +/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */ +static char *dev_addr; +module_param(dev_addr, charp, S_IRUGO); +MODULE_PARM_DESC(dev_addr, "Device Ethernet Address"); + +/* this address is invisible to ifconfig */ +static char *host_addr; +module_param(host_addr, charp, S_IRUGO); +MODULE_PARM_DESC(host_addr, "Host Ethernet Address"); + + +static u8 __init nibble(unsigned char c) +{ + if (isdigit(c)) + return c - '0'; + c = toupper(c); + if (isxdigit(c)) + return 10 + c - 'A'; + return 0; +} + +static int __init get_ether_addr(const char *str, u8 *dev_addr) +{ + if (str) { + unsigned i; + + for (i = 0; i < 6; i++) { + unsigned char num; + + if ((*str == '.') || (*str == ':')) + str++; + num = nibble(*str++) << 4; + num |= (nibble(*str++)); + dev_addr [i] = num; + } + if (is_valid_ether_addr(dev_addr)) + return 0; + } + random_ether_addr(dev_addr); + return 1; +} + +static struct eth_dev *the_dev; + + +/** + * gether_setup - initialize one ethernet-over-usb link + * @g: gadget to associated with these links + * @ethaddr: NULL, or a buffer in which the ethernet address of the + * host side of the link is recorded + * Context: may sleep + * + * This sets up the single network link that may be exported by a + * gadget driver using this framework. The link layer addresses are + * set up using module parameters. + * + * Returns negative errno, or zero on success + */ +int __init gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]) +{ + struct eth_dev *dev; + struct net_device *net; + int status; + + if (the_dev) + return -EBUSY; + + net = alloc_etherdev(sizeof *dev); + if (!net) + return -ENOMEM; + + dev = netdev_priv(net); + spin_lock_init(&dev->lock); + spin_lock_init(&dev->req_lock); + INIT_WORK(&dev->work, eth_work); + INIT_LIST_HEAD(&dev->tx_reqs); + INIT_LIST_HEAD(&dev->rx_reqs); + + /* network device setup */ + dev->net = net; + strcpy(net->name, "usb%d"); + + if (get_ether_addr(dev_addr, net->dev_addr)) + dev_warn(&g->dev, + "using random %s ethernet address\n", "self"); + if (get_ether_addr(host_addr, dev->host_mac)) + dev_warn(&g->dev, + "using random %s ethernet address\n", "host"); + + if (ethaddr) + memcpy(ethaddr, dev->host_mac, ETH_ALEN); + + net->change_mtu = eth_change_mtu; + net->hard_start_xmit = eth_start_xmit; + net->open = eth_open; + net->stop = eth_stop; + /* watchdog_timeo, tx_timeout ... */ + /* set_multicast_list */ + SET_ETHTOOL_OPS(net, &ops); + + /* two kinds of host-initiated state changes: + * - iff DATA transfer is active, carrier is "on" + * - tx queueing enabled if open *and* carrier is "on" + */ + netif_stop_queue(net); + netif_carrier_off(net); + + dev->gadget = g; + SET_NETDEV_DEV(net, &g->dev); + + status = register_netdev(net); + if (status < 0) { + dev_dbg(&g->dev, "register_netdev failed, %d\n", status); + free_netdev(net); + } else { + DECLARE_MAC_BUF(tmp); + + INFO(dev, "MAC %s\n", print_mac(tmp, net->dev_addr)); + INFO(dev, "HOST MAC %s\n", print_mac(tmp, dev->host_mac)); + + the_dev = dev; + } + + return status; +} + +/** + * gether_cleanup - remove Ethernet-over-USB device + * Context: may sleep + * + * This is called to free all resources allocated by @gether_setup(). + */ +void gether_cleanup(void) +{ + if (!the_dev) + return; + + unregister_netdev(the_dev->net); + free_netdev(the_dev->net); + + /* assuming we used keventd, it must quiesce too */ + flush_scheduled_work(); + + the_dev = NULL; +} + + +/** + * gether_connect - notify network layer that USB link is active + * @link: the USB link, set up with endpoints, descriptors matching + * current device speed, and any framing wrapper(s) set up. + * Context: irqs blocked + * + * This is called to activate endpoints and let the network layer know + * the connection is active ("carrier detect"). It may cause the I/O + * queues to open and start letting network packets flow, but will in + * any case activate the endpoints so that they respond properly to the + * USB host. + * + * Verify net_device pointer returned using IS_ERR(). If it doesn't + * indicate some error code (negative errno), ep->driver_data values + * have been overwritten. + */ +struct net_device *gether_connect(struct gether *link) +{ + struct eth_dev *dev = the_dev; + int result = 0; + + if (!dev) + return ERR_PTR(-EINVAL); + + link->in_ep->driver_data = dev; + result = usb_ep_enable(link->in_ep, link->in); + if (result != 0) { + DBG(dev, "enable %s --> %d\n", + link->in_ep->name, result); + goto fail0; + } + + link->out_ep->driver_data = dev; + result = usb_ep_enable(link->out_ep, link->out); + if (result != 0) { + DBG(dev, "enable %s --> %d\n", + link->out_ep->name, result); + goto fail1; + } + + if (result == 0) + result = alloc_requests(dev, link, qlen(dev->gadget)); + + if (result == 0) { + dev->zlp = link->is_zlp_ok; + DBG(dev, "qlen %d\n", qlen(dev->gadget)); + + dev->header_len = link->header_len; + dev->unwrap = link->unwrap; + dev->wrap = link->wrap; + + spin_lock(&dev->lock); + dev->port_usb = link; + link->ioport = dev; + spin_unlock(&dev->lock); + + netif_carrier_on(dev->net); + if (netif_running(dev->net)) + eth_start(dev, GFP_ATOMIC); + + /* on error, disable any endpoints */ + } else { + (void) usb_ep_disable(link->out_ep); +fail1: + (void) usb_ep_disable(link->in_ep); + } +fail0: + /* caller is responsible for cleanup on error */ + if (result < 0) + return ERR_PTR(result); + return dev->net; +} + +/** + * gether_disconnect - notify network layer that USB link is inactive + * @link: the USB link, on which gether_connect() was called + * Context: irqs blocked + * + * This is called to deactivate endpoints and let the network layer know + * the connection went inactive ("no carrier"). + * + * On return, the state is as if gether_connect() had never been called. + * The endpoints are inactive, and accordingly without active USB I/O. + * Pointers to endpoint descriptors and endpoint private data are nulled. + */ +void gether_disconnect(struct gether *link) +{ + struct eth_dev *dev = link->ioport; + struct usb_request *req; + + WARN_ON(!dev); + if (!dev) + return; + + DBG(dev, "%s\n", __func__); + + netif_stop_queue(dev->net); + netif_carrier_off(dev->net); + + /* disable endpoints, forcing (synchronous) completion + * of all pending i/o. then free the request objects + * and forget about the endpoints. + */ + usb_ep_disable(link->in_ep); + spin_lock(&dev->req_lock); + while (!list_empty(&dev->tx_reqs)) { + req = container_of(dev->tx_reqs.next, + struct usb_request, list); + list_del(&req->list); + + spin_unlock(&dev->req_lock); + usb_ep_free_request(link->in_ep, req); + spin_lock(&dev->req_lock); + } + spin_unlock(&dev->req_lock); + link->in_ep->driver_data = NULL; + link->in = NULL; + + usb_ep_disable(link->out_ep); + spin_lock(&dev->req_lock); + while (!list_empty(&dev->rx_reqs)) { + req = container_of(dev->rx_reqs.next, + struct usb_request, list); + list_del(&req->list); + + spin_unlock(&dev->req_lock); + usb_ep_free_request(link->out_ep, req); + spin_lock(&dev->req_lock); + } + spin_unlock(&dev->req_lock); + link->out_ep->driver_data = NULL; + link->out = NULL; + + /* finish forgetting about this USB link episode */ + dev->header_len = 0; + dev->unwrap = NULL; + dev->wrap = NULL; + + spin_lock(&dev->lock); + dev->port_usb = NULL; + link->ioport = NULL; + spin_unlock(&dev->lock); +} |