1/******************************************************************************
2 *  usbatm.c - Generic USB xDSL driver core
3 *
4 *  Copyright (C) 2001, Alcatel
5 *  Copyright (C) 2003, Duncan Sands, SolNegro, Josep Comas
6 *  Copyright (C) 2004, David Woodhouse, Roman Kagan
7 *
8 *  This program is free software; you can redistribute it and/or modify it
9 *  under the terms of the GNU General Public License as published by the Free
10 *  Software Foundation; either version 2 of the License, or (at your option)
11 *  any later version.
12 *
13 *  This program is distributed in the hope that it will be useful, but WITHOUT
14 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16 *  more details.
17 *
18 *  You should have received a copy of the GNU General Public License along with
19 *  this program; if not, write to the Free Software Foundation, Inc., 59
20 *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
21 *
22 ******************************************************************************/
23
24/*
25 *  Written by Johan Verrept, Duncan Sands (duncan.sands@free.fr) and David Woodhouse
26 *
27 *  1.7+:	- See the check-in logs
28 *
29 *  1.6:	- No longer opens a connection if the firmware is not loaded
30 *  		- Added support for the speedtouch 330
31 *  		- Removed the limit on the number of devices
32 *  		- Module now autoloads on device plugin
33 *  		- Merged relevant parts of sarlib
34 *  		- Replaced the kernel thread with a tasklet
35 *  		- New packet transmission code
36 *  		- Changed proc file contents
37 *  		- Fixed all known SMP races
38 *  		- Many fixes and cleanups
39 *  		- Various fixes by Oliver Neukum (oliver@neukum.name)
40 *
41 *  1.5A:	- Version for inclusion in 2.5 series kernel
42 *		- Modifications by Richard Purdie (rpurdie@rpsys.net)
43 *		- made compatible with kernel 2.5.6 onwards by changing
44 *		usbatm_usb_send_data_context->urb to a pointer and adding code
45 *		to alloc and free it
46 *		- remove_wait_queue() added to usbatm_atm_processqueue_thread()
47 *
48 *  1.5:	- fixed memory leak when atmsar_decode_aal5 returned NULL.
49 *		(reported by stephen.robinson@zen.co.uk)
50 *
51 *  1.4:	- changed the spin_lock() under interrupt to spin_lock_irqsave()
52 *		- unlink all active send urbs of a vcc that is being closed.
53 *
54 *  1.3.1:	- added the version number
55 *
56 *  1.3:	- Added multiple send urb support
57 *		- fixed memory leak and vcc->tx_inuse starvation bug
58 *		  when not enough memory left in vcc.
59 *
60 *  1.2:	- Fixed race condition in usbatm_usb_send_data()
61 *  1.1:	- Turned off packet debugging
62 *
63 */
64
65#include "usbatm.h"
66
67#include <asm/uaccess.h>
68#include <linux/crc32.h>
69#include <linux/errno.h>
70#include <linux/init.h>
71#include <linux/interrupt.h>
72#include <linux/kernel.h>
73#include <linux/module.h>
74#include <linux/moduleparam.h>
75#include <linux/netdevice.h>
76#include <linux/proc_fs.h>
77#include <linux/sched.h>
78#include <linux/signal.h>
79#include <linux/slab.h>
80#include <linux/stat.h>
81#include <linux/timer.h>
82#include <linux/wait.h>
83#include <linux/kthread.h>
84#include <linux/ratelimit.h>
85
86#ifdef VERBOSE_DEBUG
87static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
88#define PACKETDEBUG(arg...)	usbatm_print_packet(arg)
89#define vdbg(arg...)		dev_dbg(arg)
90#else
91#define PACKETDEBUG(arg...)
92#define vdbg(arg...)
93#endif
94
95#define DRIVER_AUTHOR	"Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
96#define DRIVER_VERSION	"1.10"
97#define DRIVER_DESC	"Generic USB ATM/DSL I/O, version " DRIVER_VERSION
98
99static const char usbatm_driver_name[] = "usbatm";
100
101#define UDSL_MAX_RCV_URBS		16
102#define UDSL_MAX_SND_URBS		16
103#define UDSL_MAX_BUF_SIZE		65536
104#define UDSL_DEFAULT_RCV_URBS		4
105#define UDSL_DEFAULT_SND_URBS		4
106#define UDSL_DEFAULT_RCV_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
107#define UDSL_DEFAULT_SND_BUF_SIZE	3392	/* 64 * ATM_CELL_SIZE */
108
109#define ATM_CELL_HEADER			(ATM_CELL_SIZE - ATM_CELL_PAYLOAD)
110
111#define THROTTLE_MSECS			100	/* delay to recover processing after urb submission fails */
112
113static unsigned int num_rcv_urbs = UDSL_DEFAULT_RCV_URBS;
114static unsigned int num_snd_urbs = UDSL_DEFAULT_SND_URBS;
115static unsigned int rcv_buf_bytes = UDSL_DEFAULT_RCV_BUF_SIZE;
116static unsigned int snd_buf_bytes = UDSL_DEFAULT_SND_BUF_SIZE;
117
118module_param(num_rcv_urbs, uint, S_IRUGO);
119MODULE_PARM_DESC(num_rcv_urbs,
120		 "Number of urbs used for reception (range: 0-"
121		 __MODULE_STRING(UDSL_MAX_RCV_URBS) ", default: "
122		 __MODULE_STRING(UDSL_DEFAULT_RCV_URBS) ")");
123
124module_param(num_snd_urbs, uint, S_IRUGO);
125MODULE_PARM_DESC(num_snd_urbs,
126		 "Number of urbs used for transmission (range: 0-"
127		 __MODULE_STRING(UDSL_MAX_SND_URBS) ", default: "
128		 __MODULE_STRING(UDSL_DEFAULT_SND_URBS) ")");
129
130module_param(rcv_buf_bytes, uint, S_IRUGO);
131MODULE_PARM_DESC(rcv_buf_bytes,
132		 "Size of the buffers used for reception, in bytes (range: 1-"
133		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
134		 __MODULE_STRING(UDSL_DEFAULT_RCV_BUF_SIZE) ")");
135
136module_param(snd_buf_bytes, uint, S_IRUGO);
137MODULE_PARM_DESC(snd_buf_bytes,
138		 "Size of the buffers used for transmission, in bytes (range: 1-"
139		 __MODULE_STRING(UDSL_MAX_BUF_SIZE) ", default: "
140		 __MODULE_STRING(UDSL_DEFAULT_SND_BUF_SIZE) ")");
141
142
143/* receive */
144
145struct usbatm_vcc_data {
146	/* vpi/vci lookup */
147	struct list_head list;
148	short vpi;
149	int vci;
150	struct atm_vcc *vcc;
151
152	/* raw cell reassembly */
153	struct sk_buff *sarb;
154};
155
156
157/* send */
158
159struct usbatm_control {
160	struct atm_skb_data atm;
161	u32 len;
162	u32 crc;
163};
164
165#define UDSL_SKB(x)		((struct usbatm_control *)(x)->cb)
166
167
168/* ATM */
169
170static void usbatm_atm_dev_close(struct atm_dev *atm_dev);
171static int usbatm_atm_open(struct atm_vcc *vcc);
172static void usbatm_atm_close(struct atm_vcc *vcc);
173static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd, void __user *arg);
174static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb);
175static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page);
176
177static struct atmdev_ops usbatm_atm_devops = {
178	.dev_close	= usbatm_atm_dev_close,
179	.open		= usbatm_atm_open,
180	.close		= usbatm_atm_close,
181	.ioctl		= usbatm_atm_ioctl,
182	.send		= usbatm_atm_send,
183	.proc_read	= usbatm_atm_proc_read,
184	.owner		= THIS_MODULE,
185};
186
187
188/***********
189**  misc  **
190***********/
191
192static inline unsigned int usbatm_pdu_length(unsigned int length)
193{
194	length += ATM_CELL_PAYLOAD - 1 + ATM_AAL5_TRAILER;
195	return length - length % ATM_CELL_PAYLOAD;
196}
197
198static inline void usbatm_pop(struct atm_vcc *vcc, struct sk_buff *skb)
199{
200	if (vcc->pop)
201		vcc->pop(vcc, skb);
202	else
203		dev_kfree_skb_any(skb);
204}
205
206
207/***********
208**  urbs  **
209************/
210
211static struct urb *usbatm_pop_urb(struct usbatm_channel *channel)
212{
213	struct urb *urb;
214
215	spin_lock_irq(&channel->lock);
216	if (list_empty(&channel->list)) {
217		spin_unlock_irq(&channel->lock);
218		return NULL;
219	}
220
221	urb = list_entry(channel->list.next, struct urb, urb_list);
222	list_del(&urb->urb_list);
223	spin_unlock_irq(&channel->lock);
224
225	return urb;
226}
227
228static int usbatm_submit_urb(struct urb *urb)
229{
230	struct usbatm_channel *channel = urb->context;
231	int ret;
232
233	/* vdbg("%s: submitting urb 0x%p, size %u",
234	     __func__, urb, urb->transfer_buffer_length); */
235
236	ret = usb_submit_urb(urb, GFP_ATOMIC);
237	if (ret) {
238		if (printk_ratelimit())
239			atm_warn(channel->usbatm, "%s: urb 0x%p submission failed (%d)!\n",
240				__func__, urb, ret);
241
242		/* consider all errors transient and return the buffer back to the queue */
243		urb->status = -EAGAIN;
244		spin_lock_irq(&channel->lock);
245
246		/* must add to the front when sending; doesn't matter when receiving */
247		list_add(&urb->urb_list, &channel->list);
248
249		spin_unlock_irq(&channel->lock);
250
251		/* make sure the channel doesn't stall */
252		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
253	}
254
255	return ret;
256}
257
258static void usbatm_complete(struct urb *urb)
259{
260	struct usbatm_channel *channel = urb->context;
261	unsigned long flags;
262	int status = urb->status;
263
264	/* vdbg("%s: urb 0x%p, status %d, actual_length %d",
265	     __func__, urb, status, urb->actual_length); */
266
267	/* usually in_interrupt(), but not always */
268	spin_lock_irqsave(&channel->lock, flags);
269
270	/* must add to the back when receiving; doesn't matter when sending */
271	list_add_tail(&urb->urb_list, &channel->list);
272
273	spin_unlock_irqrestore(&channel->lock, flags);
274
275	if (unlikely(status) &&
276			(!(channel->usbatm->flags & UDSL_IGNORE_EILSEQ) ||
277			 status != -EILSEQ)) {
278		if (status == -ESHUTDOWN)
279			return;
280
281		if (printk_ratelimit())
282			atm_warn(channel->usbatm, "%s: urb 0x%p failed (%d)!\n",
283				__func__, urb, status);
284		/* throttle processing in case of an error */
285		mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS));
286	} else
287		tasklet_schedule(&channel->tasklet);
288}
289
290
291/*************
292**  decode  **
293*************/
294
295static inline struct usbatm_vcc_data *usbatm_find_vcc(struct usbatm_data *instance,
296						  short vpi, int vci)
297{
298	struct usbatm_vcc_data *vcc_data;
299
300	list_for_each_entry(vcc_data, &instance->vcc_list, list)
301		if ((vcc_data->vci == vci) && (vcc_data->vpi == vpi))
302			return vcc_data;
303	return NULL;
304}
305
306static void usbatm_extract_one_cell(struct usbatm_data *instance, unsigned char *source)
307{
308	struct atm_vcc *vcc;
309	struct sk_buff *sarb;
310	short vpi = ((source[0] & 0x0f) << 4)  | (source[1] >> 4);
311	int vci = ((source[1] & 0x0f) << 12) | (source[2] << 4) | (source[3] >> 4);
312	u8 pti = ((source[3] & 0xe) >> 1);
313
314	if ((vci != instance->cached_vci) || (vpi != instance->cached_vpi)) {
315		instance->cached_vpi = vpi;
316		instance->cached_vci = vci;
317
318		instance->cached_vcc = usbatm_find_vcc(instance, vpi, vci);
319
320		if (!instance->cached_vcc)
321			atm_rldbg(instance, "%s: unknown vpi/vci (%hd/%d)!\n", __func__, vpi, vci);
322	}
323
324	if (!instance->cached_vcc)
325		return;
326
327	vcc = instance->cached_vcc->vcc;
328
329	/* OAM F5 end-to-end */
330	if (pti == ATM_PTI_E2EF5) {
331		if (printk_ratelimit())
332			atm_warn(instance, "%s: OAM not supported (vpi %d, vci %d)!\n",
333				__func__, vpi, vci);
334		atomic_inc(&vcc->stats->rx_err);
335		return;
336	}
337
338	sarb = instance->cached_vcc->sarb;
339
340	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
341		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
342				__func__, sarb->len, vcc);
343		/* discard cells already received */
344		skb_trim(sarb, 0);
345	}
346
347	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
348	__skb_put(sarb, ATM_CELL_PAYLOAD);
349
350	if (pti & 1) {
351		struct sk_buff *skb;
352		unsigned int length;
353		unsigned int pdu_length;
354
355		length = (source[ATM_CELL_SIZE - 6] << 8) + source[ATM_CELL_SIZE - 5];
356
357		/* guard against overflow */
358		if (length > ATM_MAX_AAL5_PDU) {
359			atm_rldbg(instance, "%s: bogus length %u (vcc: 0x%p)!\n",
360				  __func__, length, vcc);
361			atomic_inc(&vcc->stats->rx_err);
362			goto out;
363		}
364
365		pdu_length = usbatm_pdu_length(length);
366
367		if (sarb->len < pdu_length) {
368			atm_rldbg(instance, "%s: bogus pdu_length %u (sarb->len: %u, vcc: 0x%p)!\n",
369				  __func__, pdu_length, sarb->len, vcc);
370			atomic_inc(&vcc->stats->rx_err);
371			goto out;
372		}
373
374		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
375			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
376				  __func__, vcc);
377			atomic_inc(&vcc->stats->rx_err);
378			goto out;
379		}
380
381		vdbg(&instance->usb_intf->dev,
382		     "%s: got packet (length: %u, pdu_length: %u, vcc: 0x%p)",
383		     __func__, length, pdu_length, vcc);
384
385		skb = dev_alloc_skb(length);
386		if (!skb) {
387			if (printk_ratelimit())
388				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
389					__func__, length);
390			atomic_inc(&vcc->stats->rx_drop);
391			goto out;
392		}
393
394		vdbg(&instance->usb_intf->dev,
395		     "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
396		     __func__, skb, skb->truesize);
397
398		if (!atm_charge(vcc, skb->truesize)) {
399			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
400				  __func__, skb->truesize);
401			dev_kfree_skb_any(skb);
402			goto out;	/* atm_charge increments rx_drop */
403		}
404
405		skb_copy_to_linear_data(skb,
406					skb_tail_pointer(sarb) - pdu_length,
407					length);
408		__skb_put(skb, length);
409
410		vdbg(&instance->usb_intf->dev,
411		     "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
412		     __func__, skb, skb->len, skb->truesize);
413
414		PACKETDEBUG(instance, skb->data, skb->len);
415
416		vcc->push(vcc, skb);
417
418		atomic_inc(&vcc->stats->rx);
419	out:
420		skb_trim(sarb, 0);
421	}
422}
423
424static void usbatm_extract_cells(struct usbatm_data *instance,
425		unsigned char *source, unsigned int avail_data)
426{
427	unsigned int stride = instance->rx_channel.stride;
428	unsigned int buf_usage = instance->buf_usage;
429
430	/* extract cells from incoming data, taking into account that
431	 * the length of avail data may not be a multiple of stride */
432
433	if (buf_usage > 0) {
434		/* we have a partially received atm cell */
435		unsigned char *cell_buf = instance->cell_buf;
436		unsigned int space_left = stride - buf_usage;
437
438		if (avail_data >= space_left) {
439			/* add new data and process cell */
440			memcpy(cell_buf + buf_usage, source, space_left);
441			source += space_left;
442			avail_data -= space_left;
443			usbatm_extract_one_cell(instance, cell_buf);
444			instance->buf_usage = 0;
445		} else {
446			/* not enough data to fill the cell */
447			memcpy(cell_buf + buf_usage, source, avail_data);
448			instance->buf_usage = buf_usage + avail_data;
449			return;
450		}
451	}
452
453	for (; avail_data >= stride; avail_data -= stride, source += stride)
454		usbatm_extract_one_cell(instance, source);
455
456	if (avail_data > 0) {
457		/* length was not a multiple of stride -
458		 * save remaining data for next call */
459		memcpy(instance->cell_buf, source, avail_data);
460		instance->buf_usage = avail_data;
461	}
462}
463
464
465/*************
466**  encode  **
467*************/
468
469static unsigned int usbatm_write_cells(struct usbatm_data *instance,
470				       struct sk_buff *skb,
471				       u8 *target, unsigned int avail_space)
472{
473	struct usbatm_control *ctrl = UDSL_SKB(skb);
474	struct atm_vcc *vcc = ctrl->atm.vcc;
475	unsigned int bytes_written;
476	unsigned int stride = instance->tx_channel.stride;
477
478	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
479	     bytes_written += stride, target += stride) {
480		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
481		unsigned int left = ATM_CELL_PAYLOAD - data_len;
482		u8 *ptr = target;
483
484		ptr[0] = vcc->vpi >> 4;
485		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
486		ptr[2] = vcc->vci >> 4;
487		ptr[3] = vcc->vci << 4;
488		ptr[4] = 0xec;
489		ptr += ATM_CELL_HEADER;
490
491		skb_copy_from_linear_data(skb, ptr, data_len);
492		ptr += data_len;
493		__skb_pull(skb, data_len);
494
495		if (!left)
496			continue;
497
498		memset(ptr, 0, left);
499
500		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
501			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
502			/* trailer[0] = 0;		UU = 0 */
503			/* trailer[1] = 0;		CPI = 0 */
504			trailer[2] = ctrl->len >> 8;
505			trailer[3] = ctrl->len;
506
507			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
508
509			trailer[4] = ctrl->crc >> 24;
510			trailer[5] = ctrl->crc >> 16;
511			trailer[6] = ctrl->crc >> 8;
512			trailer[7] = ctrl->crc;
513
514			target[3] |= 0x2;	/* adjust PTI */
515
516			ctrl->len = 0;		/* tag this skb finished */
517		} else
518			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
519	}
520
521	return bytes_written;
522}
523
524
525/**************
526**  receive  **
527**************/
528
529static void usbatm_rx_process(unsigned long data)
530{
531	struct usbatm_data *instance = (struct usbatm_data *)data;
532	struct urb *urb;
533
534	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
535		vdbg(&instance->usb_intf->dev,
536		     "%s: processing urb 0x%p", __func__, urb);
537
538		if (usb_pipeisoc(urb->pipe)) {
539			unsigned char *merge_start = NULL;
540			unsigned int merge_length = 0;
541			const unsigned int packet_size = instance->rx_channel.packet_size;
542			int i;
543
544			for (i = 0; i < urb->number_of_packets; i++) {
545				if (!urb->iso_frame_desc[i].status) {
546					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
547
548					if (!merge_length)
549						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
550					merge_length += actual_length;
551					if (merge_length && (actual_length < packet_size)) {
552						usbatm_extract_cells(instance, merge_start, merge_length);
553						merge_length = 0;
554					}
555				} else {
556					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
557					if (merge_length)
558						usbatm_extract_cells(instance, merge_start, merge_length);
559					merge_length = 0;
560					instance->buf_usage = 0;
561				}
562			}
563
564			if (merge_length)
565				usbatm_extract_cells(instance, merge_start, merge_length);
566		} else
567			if (!urb->status)
568				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
569			else
570				instance->buf_usage = 0;
571
572		if (usbatm_submit_urb(urb))
573			return;
574	}
575}
576
577
578/***********
579**  send  **
580***********/
581
582static void usbatm_tx_process(unsigned long data)
583{
584	struct usbatm_data *instance = (struct usbatm_data *)data;
585	struct sk_buff *skb = instance->current_skb;
586	struct urb *urb = NULL;
587	const unsigned int buf_size = instance->tx_channel.buf_size;
588	unsigned int bytes_written = 0;
589	u8 *buffer = NULL;
590
591	if (!skb)
592		skb = skb_dequeue(&instance->sndqueue);
593
594	while (skb) {
595		if (!urb) {
596			urb = usbatm_pop_urb(&instance->tx_channel);
597			if (!urb)
598				break;		/* no more senders */
599			buffer = urb->transfer_buffer;
600			bytes_written = (urb->status == -EAGAIN) ?
601				urb->transfer_buffer_length : 0;
602		}
603
604		bytes_written += usbatm_write_cells(instance, skb,
605						  buffer + bytes_written,
606						  buf_size - bytes_written);
607
608		vdbg(&instance->usb_intf->dev,
609		     "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
610		     __func__, bytes_written, skb, urb);
611
612		if (!UDSL_SKB(skb)->len) {
613			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
614
615			usbatm_pop(vcc, skb);
616			atomic_inc(&vcc->stats->tx);
617
618			skb = skb_dequeue(&instance->sndqueue);
619		}
620
621		if (bytes_written == buf_size || (!skb && bytes_written)) {
622			urb->transfer_buffer_length = bytes_written;
623
624			if (usbatm_submit_urb(urb))
625				break;
626			urb = NULL;
627		}
628	}
629
630	instance->current_skb = skb;
631}
632
633static void usbatm_cancel_send(struct usbatm_data *instance,
634			       struct atm_vcc *vcc)
635{
636	struct sk_buff *skb, *n;
637
638	spin_lock_irq(&instance->sndqueue.lock);
639	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
640		if (UDSL_SKB(skb)->atm.vcc == vcc) {
641			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
642			__skb_unlink(skb, &instance->sndqueue);
643			usbatm_pop(vcc, skb);
644		}
645	}
646	spin_unlock_irq(&instance->sndqueue.lock);
647
648	tasklet_disable(&instance->tx_channel.tasklet);
649	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
650		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
651		instance->current_skb = NULL;
652		usbatm_pop(vcc, skb);
653	}
654	tasklet_enable(&instance->tx_channel.tasklet);
655}
656
657static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
658{
659	struct usbatm_data *instance = vcc->dev->dev_data;
660	struct usbatm_control *ctrl = UDSL_SKB(skb);
661	int err;
662
663	/* racy disconnection check - fine */
664	if (!instance || instance->disconnected) {
665#ifdef VERBOSE_DEBUG
666		printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
667#endif
668		err = -ENODEV;
669		goto fail;
670	}
671
672	if (vcc->qos.aal != ATM_AAL5) {
673		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
674		err = -EINVAL;
675		goto fail;
676	}
677
678	if (skb->len > ATM_MAX_AAL5_PDU) {
679		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
680				__func__, skb->len, ATM_MAX_AAL5_PDU);
681		err = -EINVAL;
682		goto fail;
683	}
684
685	PACKETDEBUG(instance, skb->data, skb->len);
686
687	/* initialize the control block */
688	ctrl->atm.vcc = vcc;
689	ctrl->len = skb->len;
690	ctrl->crc = crc32_be(~0, skb->data, skb->len);
691
692	skb_queue_tail(&instance->sndqueue, skb);
693	tasklet_schedule(&instance->tx_channel.tasklet);
694
695	return 0;
696
697 fail:
698	usbatm_pop(vcc, skb);
699	return err;
700}
701
702
703/********************
704**  bean counting  **
705********************/
706
707static void usbatm_destroy_instance(struct kref *kref)
708{
709	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
710
711	tasklet_kill(&instance->rx_channel.tasklet);
712	tasklet_kill(&instance->tx_channel.tasklet);
713	usb_put_dev(instance->usb_dev);
714	kfree(instance);
715}
716
717static void usbatm_get_instance(struct usbatm_data *instance)
718{
719	kref_get(&instance->refcount);
720}
721
722static void usbatm_put_instance(struct usbatm_data *instance)
723{
724	kref_put(&instance->refcount, usbatm_destroy_instance);
725}
726
727
728/**********
729**  ATM  **
730**********/
731
732static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
733{
734	struct usbatm_data *instance = atm_dev->dev_data;
735
736	if (!instance)
737		return;
738
739	atm_dev->dev_data = NULL; /* catch bugs */
740	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
741}
742
743static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
744{
745	struct usbatm_data *instance = atm_dev->dev_data;
746	int left = *pos;
747
748	if (!instance)
749		return -ENODEV;
750
751	if (!left--)
752		return sprintf(page, "%s\n", instance->description);
753
754	if (!left--)
755		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
756
757	if (!left--)
758		return sprintf(page,
759			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
760			       atomic_read(&atm_dev->stats.aal5.tx),
761			       atomic_read(&atm_dev->stats.aal5.tx_err),
762			       atomic_read(&atm_dev->stats.aal5.rx),
763			       atomic_read(&atm_dev->stats.aal5.rx_err),
764			       atomic_read(&atm_dev->stats.aal5.rx_drop));
765
766	if (!left--) {
767		if (instance->disconnected)
768			return sprintf(page, "Disconnected\n");
769		else
770			switch (atm_dev->signal) {
771			case ATM_PHY_SIG_FOUND:
772				return sprintf(page, "Line up\n");
773			case ATM_PHY_SIG_LOST:
774				return sprintf(page, "Line down\n");
775			default:
776				return sprintf(page, "Line state unknown\n");
777			}
778	}
779
780	return 0;
781}
782
783static int usbatm_atm_open(struct atm_vcc *vcc)
784{
785	struct usbatm_data *instance = vcc->dev->dev_data;
786	struct usbatm_vcc_data *new = NULL;
787	int ret;
788	int vci = vcc->vci;
789	short vpi = vcc->vpi;
790
791	if (!instance)
792		return -ENODEV;
793
794	/* only support AAL5 */
795	if ((vcc->qos.aal != ATM_AAL5)) {
796		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
797		return -EINVAL;
798	}
799
800	/* sanity checks */
801	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
802		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
803		return -EINVAL;
804	}
805
806	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
807
808	if (instance->disconnected) {
809		atm_dbg(instance, "%s: disconnected!\n", __func__);
810		ret = -ENODEV;
811		goto fail;
812	}
813
814	if (usbatm_find_vcc(instance, vpi, vci)) {
815		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
816		ret = -EADDRINUSE;
817		goto fail;
818	}
819
820	new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL);
821	if (!new) {
822		atm_err(instance, "%s: no memory for vcc_data!\n", __func__);
823		ret = -ENOMEM;
824		goto fail;
825	}
826
827	new->vcc = vcc;
828	new->vpi = vpi;
829	new->vci = vci;
830
831	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
832	if (!new->sarb) {
833		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
834		ret = -ENOMEM;
835		goto fail;
836	}
837
838	vcc->dev_data = new;
839
840	tasklet_disable(&instance->rx_channel.tasklet);
841	instance->cached_vcc = new;
842	instance->cached_vpi = vpi;
843	instance->cached_vci = vci;
844	list_add(&new->list, &instance->vcc_list);
845	tasklet_enable(&instance->rx_channel.tasklet);
846
847	set_bit(ATM_VF_ADDR, &vcc->flags);
848	set_bit(ATM_VF_PARTIAL, &vcc->flags);
849	set_bit(ATM_VF_READY, &vcc->flags);
850
851	mutex_unlock(&instance->serialize);
852
853	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
854
855	return 0;
856
857fail:
858	kfree(new);
859	mutex_unlock(&instance->serialize);
860	return ret;
861}
862
863static void usbatm_atm_close(struct atm_vcc *vcc)
864{
865	struct usbatm_data *instance = vcc->dev->dev_data;
866	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
867
868	if (!instance || !vcc_data)
869		return;
870
871	usbatm_cancel_send(instance, vcc);
872
873	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
874
875	tasklet_disable(&instance->rx_channel.tasklet);
876	if (instance->cached_vcc == vcc_data) {
877		instance->cached_vcc = NULL;
878		instance->cached_vpi = ATM_VPI_UNSPEC;
879		instance->cached_vci = ATM_VCI_UNSPEC;
880	}
881	list_del(&vcc_data->list);
882	tasklet_enable(&instance->rx_channel.tasklet);
883
884	kfree_skb(vcc_data->sarb);
885	vcc_data->sarb = NULL;
886
887	kfree(vcc_data);
888	vcc->dev_data = NULL;
889
890	vcc->vpi = ATM_VPI_UNSPEC;
891	vcc->vci = ATM_VCI_UNSPEC;
892	clear_bit(ATM_VF_READY, &vcc->flags);
893	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
894	clear_bit(ATM_VF_ADDR, &vcc->flags);
895
896	mutex_unlock(&instance->serialize);
897}
898
899static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
900			  void __user *arg)
901{
902	struct usbatm_data *instance = atm_dev->dev_data;
903
904	if (!instance || instance->disconnected)
905		return -ENODEV;
906
907	switch (cmd) {
908	case ATM_QUERYLOOP:
909		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
910	default:
911		return -ENOIOCTLCMD;
912	}
913}
914
915static int usbatm_atm_init(struct usbatm_data *instance)
916{
917	struct atm_dev *atm_dev;
918	int ret, i;
919
920	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
921	 * condition: callbacks we register can be executed at once, before we have
922	 * initialized the struct atm_dev.  To protect against this, all callbacks
923	 * abort if atm_dev->dev_data is NULL. */
924	atm_dev = atm_dev_register(instance->driver_name,
925				   &instance->usb_intf->dev, &usbatm_atm_devops,
926				   -1, NULL);
927	if (!atm_dev) {
928		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
929		return -1;
930	}
931
932	instance->atm_dev = atm_dev;
933
934	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
935	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
936	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
937
938	/* temp init ATM device, set to 128kbit */
939	atm_dev->link_rate = 128 * 1000 / 424;
940
941	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
942		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
943		goto fail;
944	}
945
946	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
947
948	/* ready for ATM callbacks */
949	mb();
950	atm_dev->dev_data = instance;
951
952	/* submit all rx URBs */
953	for (i = 0; i < num_rcv_urbs; i++)
954		usbatm_submit_urb(instance->urbs[i]);
955
956	return 0;
957
958 fail:
959	instance->atm_dev = NULL;
960	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
961	return ret;
962}
963
964
965/**********
966**  USB  **
967**********/
968
969static int usbatm_do_heavy_init(void *arg)
970{
971	struct usbatm_data *instance = arg;
972	int ret;
973
974	allow_signal(SIGTERM);
975	complete(&instance->thread_started);
976
977	ret = instance->driver->heavy_init(instance, instance->usb_intf);
978
979	if (!ret)
980		ret = usbatm_atm_init(instance);
981
982	mutex_lock(&instance->serialize);
983	instance->thread = NULL;
984	mutex_unlock(&instance->serialize);
985
986	complete_and_exit(&instance->thread_exited, ret);
987}
988
989static int usbatm_heavy_init(struct usbatm_data *instance)
990{
991	struct task_struct *t;
992
993	t = kthread_create(usbatm_do_heavy_init, instance, "%s",
994			instance->driver->driver_name);
995	if (IS_ERR(t)) {
996		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
997				__func__, PTR_ERR(t));
998		return PTR_ERR(t);
999	}
1000
1001	instance->thread = t;
1002	wake_up_process(t);
1003	wait_for_completion(&instance->thread_started);
1004
1005	return 0;
1006}
1007
1008static void usbatm_tasklet_schedule(unsigned long data)
1009{
1010	tasklet_schedule((struct tasklet_struct *) data);
1011}
1012
1013static void usbatm_init_channel(struct usbatm_channel *channel)
1014{
1015	spin_lock_init(&channel->lock);
1016	INIT_LIST_HEAD(&channel->list);
1017	channel->delay.function = usbatm_tasklet_schedule;
1018	channel->delay.data = (unsigned long) &channel->tasklet;
1019	init_timer(&channel->delay);
1020}
1021
1022int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1023		     struct usbatm_driver *driver)
1024{
1025	struct device *dev = &intf->dev;
1026	struct usb_device *usb_dev = interface_to_usbdev(intf);
1027	struct usbatm_data *instance;
1028	char *buf;
1029	int error = -ENOMEM;
1030	int i, length;
1031	unsigned int maxpacket, num_packets;
1032
1033	/* instance init */
1034	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1035	if (!instance) {
1036		dev_err(dev, "%s: no memory for instance data!\n", __func__);
1037		return -ENOMEM;
1038	}
1039
1040	/* public fields */
1041
1042	instance->driver = driver;
1043	strlcpy(instance->driver_name, driver->driver_name,
1044		sizeof(instance->driver_name));
1045
1046	instance->usb_dev = usb_dev;
1047	instance->usb_intf = intf;
1048
1049	buf = instance->description;
1050	length = sizeof(instance->description);
1051
1052	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1053		goto bind;
1054
1055	buf += i;
1056	length -= i;
1057
1058	i = scnprintf(buf, length, " (");
1059	buf += i;
1060	length -= i;
1061
1062	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1063		goto bind;
1064
1065	buf += i;
1066	length -= i;
1067
1068	snprintf(buf, length, ")");
1069
1070 bind:
1071	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1072			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1073			goto fail_free;
1074	}
1075
1076	/* private fields */
1077
1078	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1079	mutex_init(&instance->serialize);
1080
1081	instance->thread = NULL;
1082	init_completion(&instance->thread_started);
1083	init_completion(&instance->thread_exited);
1084
1085	INIT_LIST_HEAD(&instance->vcc_list);
1086	skb_queue_head_init(&instance->sndqueue);
1087
1088	usbatm_init_channel(&instance->rx_channel);
1089	usbatm_init_channel(&instance->tx_channel);
1090	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1091	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1092	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1093	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1094	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1095
1096	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1097		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1098	else
1099		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1100
1101	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1102
1103	/* tx buffer size must be a positive multiple of the stride */
1104	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1105			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1106
1107	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1108	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1109
1110	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1111		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1112				usb_pipeendpoint(instance->rx_channel.endpoint));
1113		error = -EINVAL;
1114		goto fail_unbind;
1115	}
1116
1117	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1118
1119	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1120		num_packets--;
1121
1122	instance->rx_channel.buf_size = num_packets * maxpacket;
1123	instance->rx_channel.packet_size = maxpacket;
1124
1125	for (i = 0; i < 2; i++) {
1126		struct usbatm_channel *channel = i ?
1127			&instance->tx_channel : &instance->rx_channel;
1128
1129		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1130			__func__, channel->buf_size, i ? "tx" : "rx", channel);
1131	}
1132
1133	/* initialize urbs */
1134
1135	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1136		u8 *buffer;
1137		struct usbatm_channel *channel = i < num_rcv_urbs ?
1138			&instance->rx_channel : &instance->tx_channel;
1139		struct urb *urb;
1140		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1141
1142		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1143		if (!urb) {
1144			dev_err(dev, "%s: no memory for urb %d!\n", __func__, i);
1145			error = -ENOMEM;
1146			goto fail_unbind;
1147		}
1148
1149		instance->urbs[i] = urb;
1150
1151		/* zero the tx padding to avoid leaking information */
1152		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1153		if (!buffer) {
1154			dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1155			error = -ENOMEM;
1156			goto fail_unbind;
1157		}
1158
1159		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1160				  buffer, channel->buf_size, usbatm_complete, channel);
1161		if (iso_packets) {
1162			int j;
1163			urb->interval = 1;
1164			urb->transfer_flags = URB_ISO_ASAP;
1165			urb->number_of_packets = iso_packets;
1166			for (j = 0; j < iso_packets; j++) {
1167				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1168				urb->iso_frame_desc[j].length = channel->packet_size;
1169			}
1170		}
1171
1172		/* put all tx URBs on the list of spares */
1173		if (i >= num_rcv_urbs)
1174			list_add_tail(&urb->urb_list, &channel->list);
1175
1176		vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1177		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1178	}
1179
1180	instance->cached_vpi = ATM_VPI_UNSPEC;
1181	instance->cached_vci = ATM_VCI_UNSPEC;
1182	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1183
1184	if (!instance->cell_buf) {
1185		dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1186		error = -ENOMEM;
1187		goto fail_unbind;
1188	}
1189
1190	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1191		error = usbatm_heavy_init(instance);
1192	} else {
1193		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1194		error = usbatm_atm_init(instance);
1195	}
1196
1197	if (error < 0)
1198		goto fail_unbind;
1199
1200	usb_get_dev(usb_dev);
1201	usb_set_intfdata(intf, instance);
1202
1203	return 0;
1204
1205 fail_unbind:
1206	if (instance->driver->unbind)
1207		instance->driver->unbind(instance, intf);
1208 fail_free:
1209	kfree(instance->cell_buf);
1210
1211	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1212		if (instance->urbs[i])
1213			kfree(instance->urbs[i]->transfer_buffer);
1214		usb_free_urb(instance->urbs[i]);
1215	}
1216
1217	kfree(instance);
1218
1219	return error;
1220}
1221EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1222
1223void usbatm_usb_disconnect(struct usb_interface *intf)
1224{
1225	struct device *dev = &intf->dev;
1226	struct usbatm_data *instance = usb_get_intfdata(intf);
1227	struct usbatm_vcc_data *vcc_data;
1228	int i;
1229
1230	if (!instance) {
1231		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1232		return;
1233	}
1234
1235	usb_set_intfdata(intf, NULL);
1236
1237	mutex_lock(&instance->serialize);
1238	instance->disconnected = 1;
1239	if (instance->thread != NULL)
1240		send_sig(SIGTERM, instance->thread, 1);
1241	mutex_unlock(&instance->serialize);
1242
1243	wait_for_completion(&instance->thread_exited);
1244
1245	mutex_lock(&instance->serialize);
1246	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1247		vcc_release_async(vcc_data->vcc, -EPIPE);
1248	mutex_unlock(&instance->serialize);
1249
1250	tasklet_disable(&instance->rx_channel.tasklet);
1251	tasklet_disable(&instance->tx_channel.tasklet);
1252
1253	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1254		usb_kill_urb(instance->urbs[i]);
1255
1256	del_timer_sync(&instance->rx_channel.delay);
1257	del_timer_sync(&instance->tx_channel.delay);
1258
1259	/* turn usbatm_[rt]x_process into something close to a no-op */
1260	/* no need to take the spinlock */
1261	INIT_LIST_HEAD(&instance->rx_channel.list);
1262	INIT_LIST_HEAD(&instance->tx_channel.list);
1263
1264	tasklet_enable(&instance->rx_channel.tasklet);
1265	tasklet_enable(&instance->tx_channel.tasklet);
1266
1267	if (instance->atm_dev && instance->driver->atm_stop)
1268		instance->driver->atm_stop(instance, instance->atm_dev);
1269
1270	if (instance->driver->unbind)
1271		instance->driver->unbind(instance, intf);
1272
1273	instance->driver_data = NULL;
1274
1275	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1276		kfree(instance->urbs[i]->transfer_buffer);
1277		usb_free_urb(instance->urbs[i]);
1278	}
1279
1280	kfree(instance->cell_buf);
1281
1282	/* ATM finalize */
1283	if (instance->atm_dev) {
1284		atm_dev_deregister(instance->atm_dev);
1285		instance->atm_dev = NULL;
1286	}
1287
1288	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1289}
1290EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1291
1292
1293/***********
1294**  init  **
1295***********/
1296
1297static int __init usbatm_usb_init(void)
1298{
1299	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1300		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1301		return -EIO;
1302	}
1303
1304	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1305	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1306	    || (rcv_buf_bytes < 1)
1307	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1308	    || (snd_buf_bytes < 1)
1309	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1310		return -EINVAL;
1311
1312	return 0;
1313}
1314module_init(usbatm_usb_init);
1315
1316static void __exit usbatm_usb_exit(void)
1317{
1318}
1319module_exit(usbatm_usb_exit);
1320
1321MODULE_AUTHOR(DRIVER_AUTHOR);
1322MODULE_DESCRIPTION(DRIVER_DESC);
1323MODULE_LICENSE("GPL");
1324MODULE_VERSION(DRIVER_VERSION);
1325
1326/************
1327**  debug  **
1328************/
1329
1330#ifdef VERBOSE_DEBUG
1331static int usbatm_print_packet(struct usbatm_data *instance,
1332			       const unsigned char *data, int len)
1333{
1334	unsigned char buffer[256];
1335	int i = 0, j = 0;
1336
1337	for (i = 0; i < len;) {
1338		buffer[0] = '\0';
1339		sprintf(buffer, "%.3d :", i);
1340		for (j = 0; (j < 16) && (i < len); j++, i++)
1341			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1342		dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1343	}
1344	return i;
1345}
1346#endif
1347