usb: gadget: r8a66597-udc: fix cannot connect after rmmod gadget driver
[linux/fpc-iii.git] / drivers / usb / gadget / u_ether.c
blobb91363e88db741bcc6378ed6eb40d7698ad23b10
1 /*
2 * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
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.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 /* #define VERBOSE_DEBUG */
25 #include <linux/kernel.h>
26 #include <linux/gfp.h>
27 #include <linux/device.h>
28 #include <linux/ctype.h>
29 #include <linux/etherdevice.h>
30 #include <linux/ethtool.h>
32 #include "u_ether.h"
36 * This component encapsulates the Ethernet link glue needed to provide
37 * one (!) network link through the USB gadget stack, normally "usb0".
39 * The control and data models are handled by the function driver which
40 * connects to this code; such as CDC Ethernet (ECM or EEM),
41 * "CDC Subset", or RNDIS. That includes all descriptor and endpoint
42 * management.
44 * Link level addressing is handled by this component using module
45 * parameters; if no such parameters are provided, random link level
46 * addresses are used. Each end of the link uses one address. The
47 * host end address is exported in various ways, and is often recorded
48 * in configuration databases.
50 * The driver which assembles each configuration using such a link is
51 * responsible for ensuring that each configuration includes at most one
52 * instance of is network link. (The network layer provides ways for
53 * this single "physical" link to be used by multiple virtual links.)
56 #define UETH__VERSION "29-May-2008"
58 struct eth_dev {
59 /* lock is held while accessing port_usb
60 * or updating its backlink port_usb->ioport
62 spinlock_t lock;
63 struct gether *port_usb;
65 struct net_device *net;
66 struct usb_gadget *gadget;
68 spinlock_t req_lock; /* guard {rx,tx}_reqs */
69 struct list_head tx_reqs, rx_reqs;
70 atomic_t tx_qlen;
72 struct sk_buff_head rx_frames;
74 unsigned header_len;
75 struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
76 int (*unwrap)(struct gether *,
77 struct sk_buff *skb,
78 struct sk_buff_head *list);
80 struct work_struct work;
82 unsigned long todo;
83 #define WORK_RX_MEMORY 0
85 bool zlp;
86 u8 host_mac[ETH_ALEN];
89 /*-------------------------------------------------------------------------*/
91 #define RX_EXTRA 20 /* bytes guarding against rx overflows */
93 #define DEFAULT_QLEN 2 /* double buffering by default */
96 #ifdef CONFIG_USB_GADGET_DUALSPEED
98 static unsigned qmult = 5;
99 module_param(qmult, uint, S_IRUGO|S_IWUSR);
100 MODULE_PARM_DESC(qmult, "queue length multiplier at high speed");
102 #else /* full speed (low speed doesn't do bulk) */
103 #define qmult 1
104 #endif
106 /* for dual-speed hardware, use deeper queues at highspeed */
107 static inline int qlen(struct usb_gadget *gadget)
109 if (gadget_is_dualspeed(gadget) && gadget->speed == USB_SPEED_HIGH)
110 return qmult * DEFAULT_QLEN;
111 else
112 return DEFAULT_QLEN;
115 /*-------------------------------------------------------------------------*/
117 /* REVISIT there must be a better way than having two sets
118 * of debug calls ...
121 #undef DBG
122 #undef VDBG
123 #undef ERROR
124 #undef INFO
126 #define xprintk(d, level, fmt, args...) \
127 printk(level "%s: " fmt , (d)->net->name , ## args)
129 #ifdef DEBUG
130 #undef DEBUG
131 #define DBG(dev, fmt, args...) \
132 xprintk(dev , KERN_DEBUG , fmt , ## args)
133 #else
134 #define DBG(dev, fmt, args...) \
135 do { } while (0)
136 #endif /* DEBUG */
138 #ifdef VERBOSE_DEBUG
139 #define VDBG DBG
140 #else
141 #define VDBG(dev, fmt, args...) \
142 do { } while (0)
143 #endif /* DEBUG */
145 #define ERROR(dev, fmt, args...) \
146 xprintk(dev , KERN_ERR , fmt , ## args)
147 #define INFO(dev, fmt, args...) \
148 xprintk(dev , KERN_INFO , fmt , ## args)
150 /*-------------------------------------------------------------------------*/
152 /* NETWORK DRIVER HOOKUP (to the layer above this driver) */
154 static int ueth_change_mtu(struct net_device *net, int new_mtu)
156 struct eth_dev *dev = netdev_priv(net);
157 unsigned long flags;
158 int status = 0;
160 /* don't change MTU on "live" link (peer won't know) */
161 spin_lock_irqsave(&dev->lock, flags);
162 if (dev->port_usb)
163 status = -EBUSY;
164 else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
165 status = -ERANGE;
166 else
167 net->mtu = new_mtu;
168 spin_unlock_irqrestore(&dev->lock, flags);
170 return status;
173 static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
175 struct eth_dev *dev = netdev_priv(net);
177 strlcpy(p->driver, "g_ether", sizeof p->driver);
178 strlcpy(p->version, UETH__VERSION, sizeof p->version);
179 strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
180 strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info);
183 /* REVISIT can also support:
184 * - WOL (by tracking suspends and issuing remote wakeup)
185 * - msglevel (implies updated messaging)
186 * - ... probably more ethtool ops
189 static const struct ethtool_ops ops = {
190 .get_drvinfo = eth_get_drvinfo,
191 .get_link = ethtool_op_get_link,
194 static void defer_kevent(struct eth_dev *dev, int flag)
196 if (test_and_set_bit(flag, &dev->todo))
197 return;
198 if (!schedule_work(&dev->work))
199 ERROR(dev, "kevent %d may have been dropped\n", flag);
200 else
201 DBG(dev, "kevent %d scheduled\n", flag);
204 static void rx_complete(struct usb_ep *ep, struct usb_request *req);
206 static int
207 rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
209 struct sk_buff *skb;
210 int retval = -ENOMEM;
211 size_t size = 0;
212 struct usb_ep *out;
213 unsigned long flags;
215 spin_lock_irqsave(&dev->lock, flags);
216 if (dev->port_usb)
217 out = dev->port_usb->out_ep;
218 else
219 out = NULL;
220 spin_unlock_irqrestore(&dev->lock, flags);
222 if (!out)
223 return -ENOTCONN;
226 /* Padding up to RX_EXTRA handles minor disagreements with host.
227 * Normally we use the USB "terminate on short read" convention;
228 * so allow up to (N*maxpacket), since that memory is normally
229 * already allocated. Some hardware doesn't deal well with short
230 * reads (e.g. DMA must be N*maxpacket), so for now don't trim a
231 * byte off the end (to force hardware errors on overflow).
233 * RNDIS uses internal framing, and explicitly allows senders to
234 * pad to end-of-packet. That's potentially nice for speed, but
235 * means receivers can't recover lost synch on their own (because
236 * new packets don't only start after a short RX).
238 size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
239 size += dev->port_usb->header_len;
240 size += out->maxpacket - 1;
241 size -= size % out->maxpacket;
243 if (dev->port_usb->is_fixed)
244 size = max_t(size_t, size, dev->port_usb->fixed_out_len);
246 skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
247 if (skb == NULL) {
248 DBG(dev, "no rx skb\n");
249 goto enomem;
252 /* Some platforms perform better when IP packets are aligned,
253 * but on at least one, checksumming fails otherwise. Note:
254 * RNDIS headers involve variable numbers of LE32 values.
256 skb_reserve(skb, NET_IP_ALIGN);
258 req->buf = skb->data;
259 req->length = size;
260 req->complete = rx_complete;
261 req->context = skb;
263 retval = usb_ep_queue(out, req, gfp_flags);
264 if (retval == -ENOMEM)
265 enomem:
266 defer_kevent(dev, WORK_RX_MEMORY);
267 if (retval) {
268 DBG(dev, "rx submit --> %d\n", retval);
269 if (skb)
270 dev_kfree_skb_any(skb);
271 spin_lock_irqsave(&dev->req_lock, flags);
272 list_add(&req->list, &dev->rx_reqs);
273 spin_unlock_irqrestore(&dev->req_lock, flags);
275 return retval;
278 static void rx_complete(struct usb_ep *ep, struct usb_request *req)
280 struct sk_buff *skb = req->context, *skb2;
281 struct eth_dev *dev = ep->driver_data;
282 int status = req->status;
284 switch (status) {
286 /* normal completion */
287 case 0:
288 skb_put(skb, req->actual);
290 if (dev->unwrap) {
291 unsigned long flags;
293 spin_lock_irqsave(&dev->lock, flags);
294 if (dev->port_usb) {
295 status = dev->unwrap(dev->port_usb,
296 skb,
297 &dev->rx_frames);
298 } else {
299 dev_kfree_skb_any(skb);
300 status = -ENOTCONN;
302 spin_unlock_irqrestore(&dev->lock, flags);
303 } else {
304 skb_queue_tail(&dev->rx_frames, skb);
306 skb = NULL;
308 skb2 = skb_dequeue(&dev->rx_frames);
309 while (skb2) {
310 if (status < 0
311 || ETH_HLEN > skb2->len
312 || skb2->len > ETH_FRAME_LEN) {
313 dev->net->stats.rx_errors++;
314 dev->net->stats.rx_length_errors++;
315 DBG(dev, "rx length %d\n", skb2->len);
316 dev_kfree_skb_any(skb2);
317 goto next_frame;
319 skb2->protocol = eth_type_trans(skb2, dev->net);
320 dev->net->stats.rx_packets++;
321 dev->net->stats.rx_bytes += skb2->len;
323 /* no buffer copies needed, unless hardware can't
324 * use skb buffers.
326 status = netif_rx(skb2);
327 next_frame:
328 skb2 = skb_dequeue(&dev->rx_frames);
330 break;
332 /* software-driven interface shutdown */
333 case -ECONNRESET: /* unlink */
334 case -ESHUTDOWN: /* disconnect etc */
335 VDBG(dev, "rx shutdown, code %d\n", status);
336 goto quiesce;
338 /* for hardware automagic (such as pxa) */
339 case -ECONNABORTED: /* endpoint reset */
340 DBG(dev, "rx %s reset\n", ep->name);
341 defer_kevent(dev, WORK_RX_MEMORY);
342 quiesce:
343 dev_kfree_skb_any(skb);
344 goto clean;
346 /* data overrun */
347 case -EOVERFLOW:
348 dev->net->stats.rx_over_errors++;
349 /* FALLTHROUGH */
351 default:
352 dev->net->stats.rx_errors++;
353 DBG(dev, "rx status %d\n", status);
354 break;
357 if (skb)
358 dev_kfree_skb_any(skb);
359 if (!netif_running(dev->net)) {
360 clean:
361 spin_lock(&dev->req_lock);
362 list_add(&req->list, &dev->rx_reqs);
363 spin_unlock(&dev->req_lock);
364 req = NULL;
366 if (req)
367 rx_submit(dev, req, GFP_ATOMIC);
370 static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
372 unsigned i;
373 struct usb_request *req;
375 if (!n)
376 return -ENOMEM;
378 /* queue/recycle up to N requests */
379 i = n;
380 list_for_each_entry(req, list, list) {
381 if (i-- == 0)
382 goto extra;
384 while (i--) {
385 req = usb_ep_alloc_request(ep, GFP_ATOMIC);
386 if (!req)
387 return list_empty(list) ? -ENOMEM : 0;
388 list_add(&req->list, list);
390 return 0;
392 extra:
393 /* free extras */
394 for (;;) {
395 struct list_head *next;
397 next = req->list.next;
398 list_del(&req->list);
399 usb_ep_free_request(ep, req);
401 if (next == list)
402 break;
404 req = container_of(next, struct usb_request, list);
406 return 0;
409 static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
411 int status;
413 spin_lock(&dev->req_lock);
414 status = prealloc(&dev->tx_reqs, link->in_ep, n);
415 if (status < 0)
416 goto fail;
417 status = prealloc(&dev->rx_reqs, link->out_ep, n);
418 if (status < 0)
419 goto fail;
420 goto done;
421 fail:
422 DBG(dev, "can't alloc requests\n");
423 done:
424 spin_unlock(&dev->req_lock);
425 return status;
428 static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
430 struct usb_request *req;
431 unsigned long flags;
433 /* fill unused rxq slots with some skb */
434 spin_lock_irqsave(&dev->req_lock, flags);
435 while (!list_empty(&dev->rx_reqs)) {
436 req = container_of(dev->rx_reqs.next,
437 struct usb_request, list);
438 list_del_init(&req->list);
439 spin_unlock_irqrestore(&dev->req_lock, flags);
441 if (rx_submit(dev, req, gfp_flags) < 0) {
442 defer_kevent(dev, WORK_RX_MEMORY);
443 return;
446 spin_lock_irqsave(&dev->req_lock, flags);
448 spin_unlock_irqrestore(&dev->req_lock, flags);
451 static void eth_work(struct work_struct *work)
453 struct eth_dev *dev = container_of(work, struct eth_dev, work);
455 if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
456 if (netif_running(dev->net))
457 rx_fill(dev, GFP_KERNEL);
460 if (dev->todo)
461 DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
464 static void tx_complete(struct usb_ep *ep, struct usb_request *req)
466 struct sk_buff *skb = req->context;
467 struct eth_dev *dev = ep->driver_data;
469 switch (req->status) {
470 default:
471 dev->net->stats.tx_errors++;
472 VDBG(dev, "tx err %d\n", req->status);
473 /* FALLTHROUGH */
474 case -ECONNRESET: /* unlink */
475 case -ESHUTDOWN: /* disconnect etc */
476 break;
477 case 0:
478 dev->net->stats.tx_bytes += skb->len;
480 dev->net->stats.tx_packets++;
482 spin_lock(&dev->req_lock);
483 list_add(&req->list, &dev->tx_reqs);
484 spin_unlock(&dev->req_lock);
485 dev_kfree_skb_any(skb);
487 atomic_dec(&dev->tx_qlen);
488 if (netif_carrier_ok(dev->net))
489 netif_wake_queue(dev->net);
492 static inline int is_promisc(u16 cdc_filter)
494 return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
497 static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
498 struct net_device *net)
500 struct eth_dev *dev = netdev_priv(net);
501 int length = skb->len;
502 int retval;
503 struct usb_request *req = NULL;
504 unsigned long flags;
505 struct usb_ep *in;
506 u16 cdc_filter;
508 spin_lock_irqsave(&dev->lock, flags);
509 if (dev->port_usb) {
510 in = dev->port_usb->in_ep;
511 cdc_filter = dev->port_usb->cdc_filter;
512 } else {
513 in = NULL;
514 cdc_filter = 0;
516 spin_unlock_irqrestore(&dev->lock, flags);
518 if (!in) {
519 dev_kfree_skb_any(skb);
520 return NETDEV_TX_OK;
523 /* apply outgoing CDC or RNDIS filters */
524 if (!is_promisc(cdc_filter)) {
525 u8 *dest = skb->data;
527 if (is_multicast_ether_addr(dest)) {
528 u16 type;
530 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
531 * SET_ETHERNET_MULTICAST_FILTERS requests
533 if (is_broadcast_ether_addr(dest))
534 type = USB_CDC_PACKET_TYPE_BROADCAST;
535 else
536 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
537 if (!(cdc_filter & type)) {
538 dev_kfree_skb_any(skb);
539 return NETDEV_TX_OK;
542 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
545 spin_lock_irqsave(&dev->req_lock, flags);
547 * this freelist can be empty if an interrupt triggered disconnect()
548 * and reconfigured the gadget (shutting down this queue) after the
549 * network stack decided to xmit but before we got the spinlock.
551 if (list_empty(&dev->tx_reqs)) {
552 spin_unlock_irqrestore(&dev->req_lock, flags);
553 return NETDEV_TX_BUSY;
556 req = container_of(dev->tx_reqs.next, struct usb_request, list);
557 list_del(&req->list);
559 /* temporarily stop TX queue when the freelist empties */
560 if (list_empty(&dev->tx_reqs))
561 netif_stop_queue(net);
562 spin_unlock_irqrestore(&dev->req_lock, flags);
564 /* no buffer copies needed, unless the network stack did it
565 * or the hardware can't use skb buffers.
566 * or there's not enough space for extra headers we need
568 if (dev->wrap) {
569 unsigned long flags;
571 spin_lock_irqsave(&dev->lock, flags);
572 if (dev->port_usb)
573 skb = dev->wrap(dev->port_usb, skb);
574 spin_unlock_irqrestore(&dev->lock, flags);
575 if (!skb)
576 goto drop;
578 length = skb->len;
580 req->buf = skb->data;
581 req->context = skb;
582 req->complete = tx_complete;
584 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
585 if (dev->port_usb->is_fixed &&
586 length == dev->port_usb->fixed_in_len &&
587 (length % in->maxpacket) == 0)
588 req->zero = 0;
589 else
590 req->zero = 1;
592 /* use zlp framing on tx for strict CDC-Ether conformance,
593 * though any robust network rx path ignores extra padding.
594 * and some hardware doesn't like to write zlps.
596 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
597 length++;
599 req->length = length;
601 /* throttle highspeed IRQ rate back slightly */
602 if (gadget_is_dualspeed(dev->gadget))
603 req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
604 ? ((atomic_read(&dev->tx_qlen) % qmult) != 0)
605 : 0;
607 retval = usb_ep_queue(in, req, GFP_ATOMIC);
608 switch (retval) {
609 default:
610 DBG(dev, "tx queue err %d\n", retval);
611 break;
612 case 0:
613 net->trans_start = jiffies;
614 atomic_inc(&dev->tx_qlen);
617 if (retval) {
618 dev_kfree_skb_any(skb);
619 drop:
620 dev->net->stats.tx_dropped++;
621 spin_lock_irqsave(&dev->req_lock, flags);
622 if (list_empty(&dev->tx_reqs))
623 netif_start_queue(net);
624 list_add(&req->list, &dev->tx_reqs);
625 spin_unlock_irqrestore(&dev->req_lock, flags);
627 return NETDEV_TX_OK;
630 /*-------------------------------------------------------------------------*/
632 static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
634 DBG(dev, "%s\n", __func__);
636 /* fill the rx queue */
637 rx_fill(dev, gfp_flags);
639 /* and open the tx floodgates */
640 atomic_set(&dev->tx_qlen, 0);
641 netif_wake_queue(dev->net);
644 static int eth_open(struct net_device *net)
646 struct eth_dev *dev = netdev_priv(net);
647 struct gether *link;
649 DBG(dev, "%s\n", __func__);
650 if (netif_carrier_ok(dev->net))
651 eth_start(dev, GFP_KERNEL);
653 spin_lock_irq(&dev->lock);
654 link = dev->port_usb;
655 if (link && link->open)
656 link->open(link);
657 spin_unlock_irq(&dev->lock);
659 return 0;
662 static int eth_stop(struct net_device *net)
664 struct eth_dev *dev = netdev_priv(net);
665 unsigned long flags;
667 VDBG(dev, "%s\n", __func__);
668 netif_stop_queue(net);
670 DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
671 dev->net->stats.rx_packets, dev->net->stats.tx_packets,
672 dev->net->stats.rx_errors, dev->net->stats.tx_errors
675 /* ensure there are no more active requests */
676 spin_lock_irqsave(&dev->lock, flags);
677 if (dev->port_usb) {
678 struct gether *link = dev->port_usb;
680 if (link->close)
681 link->close(link);
683 /* NOTE: we have no abort-queue primitive we could use
684 * to cancel all pending I/O. Instead, we disable then
685 * reenable the endpoints ... this idiom may leave toggle
686 * wrong, but that's a self-correcting error.
688 * REVISIT: we *COULD* just let the transfers complete at
689 * their own pace; the network stack can handle old packets.
690 * For the moment we leave this here, since it works.
692 usb_ep_disable(link->in_ep);
693 usb_ep_disable(link->out_ep);
694 if (netif_carrier_ok(net)) {
695 DBG(dev, "host still using in/out endpoints\n");
696 usb_ep_enable(link->in_ep);
697 usb_ep_enable(link->out_ep);
700 spin_unlock_irqrestore(&dev->lock, flags);
702 return 0;
705 /*-------------------------------------------------------------------------*/
707 /* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
708 static char *dev_addr;
709 module_param(dev_addr, charp, S_IRUGO);
710 MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
712 /* this address is invisible to ifconfig */
713 static char *host_addr;
714 module_param(host_addr, charp, S_IRUGO);
715 MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
717 static int get_ether_addr(const char *str, u8 *dev_addr)
719 if (str) {
720 unsigned i;
722 for (i = 0; i < 6; i++) {
723 unsigned char num;
725 if ((*str == '.') || (*str == ':'))
726 str++;
727 num = hex_to_bin(*str++) << 4;
728 num |= hex_to_bin(*str++);
729 dev_addr [i] = num;
731 if (is_valid_ether_addr(dev_addr))
732 return 0;
734 random_ether_addr(dev_addr);
735 return 1;
738 static struct eth_dev *the_dev;
740 static const struct net_device_ops eth_netdev_ops = {
741 .ndo_open = eth_open,
742 .ndo_stop = eth_stop,
743 .ndo_start_xmit = eth_start_xmit,
744 .ndo_change_mtu = ueth_change_mtu,
745 .ndo_set_mac_address = eth_mac_addr,
746 .ndo_validate_addr = eth_validate_addr,
749 static struct device_type gadget_type = {
750 .name = "gadget",
754 * gether_setup - initialize one ethernet-over-usb link
755 * @g: gadget to associated with these links
756 * @ethaddr: NULL, or a buffer in which the ethernet address of the
757 * host side of the link is recorded
758 * Context: may sleep
760 * This sets up the single network link that may be exported by a
761 * gadget driver using this framework. The link layer addresses are
762 * set up using module parameters.
764 * Returns negative errno, or zero on success
766 int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN])
768 struct eth_dev *dev;
769 struct net_device *net;
770 int status;
772 if (the_dev)
773 return -EBUSY;
775 net = alloc_etherdev(sizeof *dev);
776 if (!net)
777 return -ENOMEM;
779 dev = netdev_priv(net);
780 spin_lock_init(&dev->lock);
781 spin_lock_init(&dev->req_lock);
782 INIT_WORK(&dev->work, eth_work);
783 INIT_LIST_HEAD(&dev->tx_reqs);
784 INIT_LIST_HEAD(&dev->rx_reqs);
786 skb_queue_head_init(&dev->rx_frames);
788 /* network device setup */
789 dev->net = net;
790 strcpy(net->name, "usb%d");
792 if (get_ether_addr(dev_addr, net->dev_addr))
793 dev_warn(&g->dev,
794 "using random %s ethernet address\n", "self");
795 if (get_ether_addr(host_addr, dev->host_mac))
796 dev_warn(&g->dev,
797 "using random %s ethernet address\n", "host");
799 if (ethaddr)
800 memcpy(ethaddr, dev->host_mac, ETH_ALEN);
802 net->netdev_ops = &eth_netdev_ops;
804 SET_ETHTOOL_OPS(net, &ops);
806 /* two kinds of host-initiated state changes:
807 * - iff DATA transfer is active, carrier is "on"
808 * - tx queueing enabled if open *and* carrier is "on"
810 netif_carrier_off(net);
812 dev->gadget = g;
813 SET_NETDEV_DEV(net, &g->dev);
814 SET_NETDEV_DEVTYPE(net, &gadget_type);
816 status = register_netdev(net);
817 if (status < 0) {
818 dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
819 free_netdev(net);
820 } else {
821 INFO(dev, "MAC %pM\n", net->dev_addr);
822 INFO(dev, "HOST MAC %pM\n", dev->host_mac);
824 the_dev = dev;
827 return status;
831 * gether_cleanup - remove Ethernet-over-USB device
832 * Context: may sleep
834 * This is called to free all resources allocated by @gether_setup().
836 void gether_cleanup(void)
838 if (!the_dev)
839 return;
841 unregister_netdev(the_dev->net);
842 flush_work_sync(&the_dev->work);
843 free_netdev(the_dev->net);
845 the_dev = NULL;
850 * gether_connect - notify network layer that USB link is active
851 * @link: the USB link, set up with endpoints, descriptors matching
852 * current device speed, and any framing wrapper(s) set up.
853 * Context: irqs blocked
855 * This is called to activate endpoints and let the network layer know
856 * the connection is active ("carrier detect"). It may cause the I/O
857 * queues to open and start letting network packets flow, but will in
858 * any case activate the endpoints so that they respond properly to the
859 * USB host.
861 * Verify net_device pointer returned using IS_ERR(). If it doesn't
862 * indicate some error code (negative errno), ep->driver_data values
863 * have been overwritten.
865 struct net_device *gether_connect(struct gether *link)
867 struct eth_dev *dev = the_dev;
868 int result = 0;
870 if (!dev)
871 return ERR_PTR(-EINVAL);
873 link->in_ep->driver_data = dev;
874 result = usb_ep_enable(link->in_ep);
875 if (result != 0) {
876 DBG(dev, "enable %s --> %d\n",
877 link->in_ep->name, result);
878 goto fail0;
881 link->out_ep->driver_data = dev;
882 result = usb_ep_enable(link->out_ep);
883 if (result != 0) {
884 DBG(dev, "enable %s --> %d\n",
885 link->out_ep->name, result);
886 goto fail1;
889 if (result == 0)
890 result = alloc_requests(dev, link, qlen(dev->gadget));
892 if (result == 0) {
893 dev->zlp = link->is_zlp_ok;
894 DBG(dev, "qlen %d\n", qlen(dev->gadget));
896 dev->header_len = link->header_len;
897 dev->unwrap = link->unwrap;
898 dev->wrap = link->wrap;
900 spin_lock(&dev->lock);
901 dev->port_usb = link;
902 link->ioport = dev;
903 if (netif_running(dev->net)) {
904 if (link->open)
905 link->open(link);
906 } else {
907 if (link->close)
908 link->close(link);
910 spin_unlock(&dev->lock);
912 netif_carrier_on(dev->net);
913 if (netif_running(dev->net))
914 eth_start(dev, GFP_ATOMIC);
916 /* on error, disable any endpoints */
917 } else {
918 (void) usb_ep_disable(link->out_ep);
919 fail1:
920 (void) usb_ep_disable(link->in_ep);
922 fail0:
923 /* caller is responsible for cleanup on error */
924 if (result < 0)
925 return ERR_PTR(result);
926 return dev->net;
930 * gether_disconnect - notify network layer that USB link is inactive
931 * @link: the USB link, on which gether_connect() was called
932 * Context: irqs blocked
934 * This is called to deactivate endpoints and let the network layer know
935 * the connection went inactive ("no carrier").
937 * On return, the state is as if gether_connect() had never been called.
938 * The endpoints are inactive, and accordingly without active USB I/O.
939 * Pointers to endpoint descriptors and endpoint private data are nulled.
941 void gether_disconnect(struct gether *link)
943 struct eth_dev *dev = link->ioport;
944 struct usb_request *req;
946 WARN_ON(!dev);
947 if (!dev)
948 return;
950 DBG(dev, "%s\n", __func__);
952 netif_stop_queue(dev->net);
953 netif_carrier_off(dev->net);
955 /* disable endpoints, forcing (synchronous) completion
956 * of all pending i/o. then free the request objects
957 * and forget about the endpoints.
959 usb_ep_disable(link->in_ep);
960 spin_lock(&dev->req_lock);
961 while (!list_empty(&dev->tx_reqs)) {
962 req = container_of(dev->tx_reqs.next,
963 struct usb_request, list);
964 list_del(&req->list);
966 spin_unlock(&dev->req_lock);
967 usb_ep_free_request(link->in_ep, req);
968 spin_lock(&dev->req_lock);
970 spin_unlock(&dev->req_lock);
971 link->in_ep->driver_data = NULL;
972 link->in_ep->desc = NULL;
974 usb_ep_disable(link->out_ep);
975 spin_lock(&dev->req_lock);
976 while (!list_empty(&dev->rx_reqs)) {
977 req = container_of(dev->rx_reqs.next,
978 struct usb_request, list);
979 list_del(&req->list);
981 spin_unlock(&dev->req_lock);
982 usb_ep_free_request(link->out_ep, req);
983 spin_lock(&dev->req_lock);
985 spin_unlock(&dev->req_lock);
986 link->out_ep->driver_data = NULL;
987 link->out_ep->desc = NULL;
989 /* finish forgetting about this USB link episode */
990 dev->header_len = 0;
991 dev->unwrap = NULL;
992 dev->wrap = NULL;
994 spin_lock(&dev->lock);
995 dev->port_usb = NULL;
996 link->ioport = NULL;
997 spin_unlock(&dev->lock);