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		if (!(skb = dev_alloc_skb(length))) {
386			if (printk_ratelimit())
387				atm_err(instance, "%s: no memory for skb (length: %u)!\n",
388					__func__, length);
389			atomic_inc(&vcc->stats->rx_drop);
390			goto out;
391		}
392
393		vdbg(&instance->usb_intf->dev,
394		     "%s: allocated new sk_buff (skb: 0x%p, skb->truesize: %u)",
395		     __func__, skb, skb->truesize);
396
397		if (!atm_charge(vcc, skb->truesize)) {
398			atm_rldbg(instance, "%s: failed atm_charge (skb->truesize: %u)!\n",
399				  __func__, skb->truesize);
400			dev_kfree_skb_any(skb);
401			goto out;	/* atm_charge increments rx_drop */
402		}
403
404		skb_copy_to_linear_data(skb,
405					skb_tail_pointer(sarb) - pdu_length,
406					length);
407		__skb_put(skb, length);
408
409		vdbg(&instance->usb_intf->dev,
410		     "%s: sending skb 0x%p, skb->len %u, skb->truesize %u",
411		     __func__, skb, skb->len, skb->truesize);
412
413		PACKETDEBUG(instance, skb->data, skb->len);
414
415		vcc->push(vcc, skb);
416
417		atomic_inc(&vcc->stats->rx);
418	out:
419		skb_trim(sarb, 0);
420	}
421}
422
423static void usbatm_extract_cells(struct usbatm_data *instance,
424		unsigned char *source, unsigned int avail_data)
425{
426	unsigned int stride = instance->rx_channel.stride;
427	unsigned int buf_usage = instance->buf_usage;
428
429	/* extract cells from incoming data, taking into account that
430	 * the length of avail data may not be a multiple of stride */
431
432	if (buf_usage > 0) {
433		/* we have a partially received atm cell */
434		unsigned char *cell_buf = instance->cell_buf;
435		unsigned int space_left = stride - buf_usage;
436
437		if (avail_data >= space_left) {
438			/* add new data and process cell */
439			memcpy(cell_buf + buf_usage, source, space_left);
440			source += space_left;
441			avail_data -= space_left;
442			usbatm_extract_one_cell(instance, cell_buf);
443			instance->buf_usage = 0;
444		} else {
445			/* not enough data to fill the cell */
446			memcpy(cell_buf + buf_usage, source, avail_data);
447			instance->buf_usage = buf_usage + avail_data;
448			return;
449		}
450	}
451
452	for (; avail_data >= stride; avail_data -= stride, source += stride)
453		usbatm_extract_one_cell(instance, source);
454
455	if (avail_data > 0) {
456		/* length was not a multiple of stride -
457		 * save remaining data for next call */
458		memcpy(instance->cell_buf, source, avail_data);
459		instance->buf_usage = avail_data;
460	}
461}
462
463
464/*************
465**  encode  **
466*************/
467
468static unsigned int usbatm_write_cells(struct usbatm_data *instance,
469				       struct sk_buff *skb,
470				       u8 *target, unsigned int avail_space)
471{
472	struct usbatm_control *ctrl = UDSL_SKB(skb);
473	struct atm_vcc *vcc = ctrl->atm.vcc;
474	unsigned int bytes_written;
475	unsigned int stride = instance->tx_channel.stride;
476
477	for (bytes_written = 0; bytes_written < avail_space && ctrl->len;
478	     bytes_written += stride, target += stride) {
479		unsigned int data_len = min_t(unsigned int, skb->len, ATM_CELL_PAYLOAD);
480		unsigned int left = ATM_CELL_PAYLOAD - data_len;
481		u8 *ptr = target;
482
483		ptr[0] = vcc->vpi >> 4;
484		ptr[1] = (vcc->vpi << 4) | (vcc->vci >> 12);
485		ptr[2] = vcc->vci >> 4;
486		ptr[3] = vcc->vci << 4;
487		ptr[4] = 0xec;
488		ptr += ATM_CELL_HEADER;
489
490		skb_copy_from_linear_data(skb, ptr, data_len);
491		ptr += data_len;
492		__skb_pull(skb, data_len);
493
494		if (!left)
495			continue;
496
497		memset(ptr, 0, left);
498
499		if (left >= ATM_AAL5_TRAILER) {	/* trailer will go in this cell */
500			u8 *trailer = target + ATM_CELL_SIZE - ATM_AAL5_TRAILER;
501			/* trailer[0] = 0;		UU = 0 */
502			/* trailer[1] = 0;		CPI = 0 */
503			trailer[2] = ctrl->len >> 8;
504			trailer[3] = ctrl->len;
505
506			ctrl->crc = ~crc32_be(ctrl->crc, ptr, left - 4);
507
508			trailer[4] = ctrl->crc >> 24;
509			trailer[5] = ctrl->crc >> 16;
510			trailer[6] = ctrl->crc >> 8;
511			trailer[7] = ctrl->crc;
512
513			target[3] |= 0x2;	/* adjust PTI */
514
515			ctrl->len = 0;		/* tag this skb finished */
516		} else
517			ctrl->crc = crc32_be(ctrl->crc, ptr, left);
518	}
519
520	return bytes_written;
521}
522
523
524/**************
525**  receive  **
526**************/
527
528static void usbatm_rx_process(unsigned long data)
529{
530	struct usbatm_data *instance = (struct usbatm_data *)data;
531	struct urb *urb;
532
533	while ((urb = usbatm_pop_urb(&instance->rx_channel))) {
534		vdbg(&instance->usb_intf->dev,
535		     "%s: processing urb 0x%p", __func__, urb);
536
537		if (usb_pipeisoc(urb->pipe)) {
538			unsigned char *merge_start = NULL;
539			unsigned int merge_length = 0;
540			const unsigned int packet_size = instance->rx_channel.packet_size;
541			int i;
542
543			for (i = 0; i < urb->number_of_packets; i++) {
544				if (!urb->iso_frame_desc[i].status) {
545					unsigned int actual_length = urb->iso_frame_desc[i].actual_length;
546
547					if (!merge_length)
548						merge_start = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
549					merge_length += actual_length;
550					if (merge_length && (actual_length < packet_size)) {
551						usbatm_extract_cells(instance, merge_start, merge_length);
552						merge_length = 0;
553					}
554				} else {
555					atm_rldbg(instance, "%s: status %d in frame %d!\n", __func__, urb->status, i);
556					if (merge_length)
557						usbatm_extract_cells(instance, merge_start, merge_length);
558					merge_length = 0;
559					instance->buf_usage = 0;
560				}
561			}
562
563			if (merge_length)
564				usbatm_extract_cells(instance, merge_start, merge_length);
565		} else
566			if (!urb->status)
567				usbatm_extract_cells(instance, urb->transfer_buffer, urb->actual_length);
568			else
569				instance->buf_usage = 0;
570
571		if (usbatm_submit_urb(urb))
572			return;
573	}
574}
575
576
577/***********
578**  send  **
579***********/
580
581static void usbatm_tx_process(unsigned long data)
582{
583	struct usbatm_data *instance = (struct usbatm_data *)data;
584	struct sk_buff *skb = instance->current_skb;
585	struct urb *urb = NULL;
586	const unsigned int buf_size = instance->tx_channel.buf_size;
587	unsigned int bytes_written = 0;
588	u8 *buffer = NULL;
589
590	if (!skb)
591		skb = skb_dequeue(&instance->sndqueue);
592
593	while (skb) {
594		if (!urb) {
595			urb = usbatm_pop_urb(&instance->tx_channel);
596			if (!urb)
597				break;		/* no more senders */
598			buffer = urb->transfer_buffer;
599			bytes_written = (urb->status == -EAGAIN) ?
600				urb->transfer_buffer_length : 0;
601		}
602
603		bytes_written += usbatm_write_cells(instance, skb,
604						  buffer + bytes_written,
605						  buf_size - bytes_written);
606
607		vdbg(&instance->usb_intf->dev,
608		     "%s: wrote %u bytes from skb 0x%p to urb 0x%p",
609		     __func__, bytes_written, skb, urb);
610
611		if (!UDSL_SKB(skb)->len) {
612			struct atm_vcc *vcc = UDSL_SKB(skb)->atm.vcc;
613
614			usbatm_pop(vcc, skb);
615			atomic_inc(&vcc->stats->tx);
616
617			skb = skb_dequeue(&instance->sndqueue);
618		}
619
620		if (bytes_written == buf_size || (!skb && bytes_written)) {
621			urb->transfer_buffer_length = bytes_written;
622
623			if (usbatm_submit_urb(urb))
624				break;
625			urb = NULL;
626		}
627	}
628
629	instance->current_skb = skb;
630}
631
632static void usbatm_cancel_send(struct usbatm_data *instance,
633			       struct atm_vcc *vcc)
634{
635	struct sk_buff *skb, *n;
636
637	spin_lock_irq(&instance->sndqueue.lock);
638	skb_queue_walk_safe(&instance->sndqueue, skb, n) {
639		if (UDSL_SKB(skb)->atm.vcc == vcc) {
640			atm_dbg(instance, "%s: popping skb 0x%p\n", __func__, skb);
641			__skb_unlink(skb, &instance->sndqueue);
642			usbatm_pop(vcc, skb);
643		}
644	}
645	spin_unlock_irq(&instance->sndqueue.lock);
646
647	tasklet_disable(&instance->tx_channel.tasklet);
648	if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) {
649		atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb);
650		instance->current_skb = NULL;
651		usbatm_pop(vcc, skb);
652	}
653	tasklet_enable(&instance->tx_channel.tasklet);
654}
655
656static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
657{
658	struct usbatm_data *instance = vcc->dev->dev_data;
659	struct usbatm_control *ctrl = UDSL_SKB(skb);
660	int err;
661
662	/* racy disconnection check - fine */
663	if (!instance || instance->disconnected) {
664#ifdef VERBOSE_DEBUG
665		printk_ratelimited(KERN_DEBUG "%s: %s!\n", __func__, instance ? "disconnected" : "NULL instance");
666#endif
667		err = -ENODEV;
668		goto fail;
669	}
670
671	if (vcc->qos.aal != ATM_AAL5) {
672		atm_rldbg(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
673		err = -EINVAL;
674		goto fail;
675	}
676
677	if (skb->len > ATM_MAX_AAL5_PDU) {
678		atm_rldbg(instance, "%s: packet too long (%d vs %d)!\n",
679				__func__, skb->len, ATM_MAX_AAL5_PDU);
680		err = -EINVAL;
681		goto fail;
682	}
683
684	PACKETDEBUG(instance, skb->data, skb->len);
685
686	/* initialize the control block */
687	ctrl->atm.vcc = vcc;
688	ctrl->len = skb->len;
689	ctrl->crc = crc32_be(~0, skb->data, skb->len);
690
691	skb_queue_tail(&instance->sndqueue, skb);
692	tasklet_schedule(&instance->tx_channel.tasklet);
693
694	return 0;
695
696 fail:
697	usbatm_pop(vcc, skb);
698	return err;
699}
700
701
702/********************
703**  bean counting  **
704********************/
705
706static void usbatm_destroy_instance(struct kref *kref)
707{
708	struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount);
709
710	tasklet_kill(&instance->rx_channel.tasklet);
711	tasklet_kill(&instance->tx_channel.tasklet);
712	usb_put_dev(instance->usb_dev);
713	kfree(instance);
714}
715
716static void usbatm_get_instance(struct usbatm_data *instance)
717{
718	kref_get(&instance->refcount);
719}
720
721static void usbatm_put_instance(struct usbatm_data *instance)
722{
723	kref_put(&instance->refcount, usbatm_destroy_instance);
724}
725
726
727/**********
728**  ATM  **
729**********/
730
731static void usbatm_atm_dev_close(struct atm_dev *atm_dev)
732{
733	struct usbatm_data *instance = atm_dev->dev_data;
734
735	if (!instance)
736		return;
737
738	atm_dev->dev_data = NULL; /* catch bugs */
739	usbatm_put_instance(instance);	/* taken in usbatm_atm_init */
740}
741
742static int usbatm_atm_proc_read(struct atm_dev *atm_dev, loff_t *pos, char *page)
743{
744	struct usbatm_data *instance = atm_dev->dev_data;
745	int left = *pos;
746
747	if (!instance)
748		return -ENODEV;
749
750	if (!left--)
751		return sprintf(page, "%s\n", instance->description);
752
753	if (!left--)
754		return sprintf(page, "MAC: %pM\n", atm_dev->esi);
755
756	if (!left--)
757		return sprintf(page,
758			       "AAL5: tx %d ( %d err ), rx %d ( %d err, %d drop )\n",
759			       atomic_read(&atm_dev->stats.aal5.tx),
760			       atomic_read(&atm_dev->stats.aal5.tx_err),
761			       atomic_read(&atm_dev->stats.aal5.rx),
762			       atomic_read(&atm_dev->stats.aal5.rx_err),
763			       atomic_read(&atm_dev->stats.aal5.rx_drop));
764
765	if (!left--) {
766		if (instance->disconnected)
767			return sprintf(page, "Disconnected\n");
768		else
769			switch (atm_dev->signal) {
770			case ATM_PHY_SIG_FOUND:
771				return sprintf(page, "Line up\n");
772			case ATM_PHY_SIG_LOST:
773				return sprintf(page, "Line down\n");
774			default:
775				return sprintf(page, "Line state unknown\n");
776			}
777	}
778
779	return 0;
780}
781
782static int usbatm_atm_open(struct atm_vcc *vcc)
783{
784	struct usbatm_data *instance = vcc->dev->dev_data;
785	struct usbatm_vcc_data *new = NULL;
786	int ret;
787	int vci = vcc->vci;
788	short vpi = vcc->vpi;
789
790	if (!instance)
791		return -ENODEV;
792
793	/* only support AAL5 */
794	if ((vcc->qos.aal != ATM_AAL5)) {
795		atm_warn(instance, "%s: unsupported ATM type %d!\n", __func__, vcc->qos.aal);
796		return -EINVAL;
797	}
798
799	/* sanity checks */
800	if ((vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)) {
801		atm_dbg(instance, "%s: max_sdu %d out of range!\n", __func__, vcc->qos.rxtp.max_sdu);
802		return -EINVAL;
803	}
804
805	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_close, usbatm_usb_disconnect */
806
807	if (instance->disconnected) {
808		atm_dbg(instance, "%s: disconnected!\n", __func__);
809		ret = -ENODEV;
810		goto fail;
811	}
812
813	if (usbatm_find_vcc(instance, vpi, vci)) {
814		atm_dbg(instance, "%s: %hd/%d already in use!\n", __func__, vpi, vci);
815		ret = -EADDRINUSE;
816		goto fail;
817	}
818
819	if (!(new = kzalloc(sizeof(struct usbatm_vcc_data), GFP_KERNEL))) {
820		atm_err(instance, "%s: no memory for vcc_data!\n", __func__);
821		ret = -ENOMEM;
822		goto fail;
823	}
824
825	new->vcc = vcc;
826	new->vpi = vpi;
827	new->vci = vci;
828
829	new->sarb = alloc_skb(usbatm_pdu_length(vcc->qos.rxtp.max_sdu), GFP_KERNEL);
830	if (!new->sarb) {
831		atm_err(instance, "%s: no memory for SAR buffer!\n", __func__);
832		ret = -ENOMEM;
833		goto fail;
834	}
835
836	vcc->dev_data = new;
837
838	tasklet_disable(&instance->rx_channel.tasklet);
839	instance->cached_vcc = new;
840	instance->cached_vpi = vpi;
841	instance->cached_vci = vci;
842	list_add(&new->list, &instance->vcc_list);
843	tasklet_enable(&instance->rx_channel.tasklet);
844
845	set_bit(ATM_VF_ADDR, &vcc->flags);
846	set_bit(ATM_VF_PARTIAL, &vcc->flags);
847	set_bit(ATM_VF_READY, &vcc->flags);
848
849	mutex_unlock(&instance->serialize);
850
851	atm_dbg(instance, "%s: allocated vcc data 0x%p\n", __func__, new);
852
853	return 0;
854
855fail:
856	kfree(new);
857	mutex_unlock(&instance->serialize);
858	return ret;
859}
860
861static void usbatm_atm_close(struct atm_vcc *vcc)
862{
863	struct usbatm_data *instance = vcc->dev->dev_data;
864	struct usbatm_vcc_data *vcc_data = vcc->dev_data;
865
866	if (!instance || !vcc_data)
867		return;
868
869	usbatm_cancel_send(instance, vcc);
870
871	mutex_lock(&instance->serialize);	/* vs self, usbatm_atm_open, usbatm_usb_disconnect */
872
873	tasklet_disable(&instance->rx_channel.tasklet);
874	if (instance->cached_vcc == vcc_data) {
875		instance->cached_vcc = NULL;
876		instance->cached_vpi = ATM_VPI_UNSPEC;
877		instance->cached_vci = ATM_VCI_UNSPEC;
878	}
879	list_del(&vcc_data->list);
880	tasklet_enable(&instance->rx_channel.tasklet);
881
882	kfree_skb(vcc_data->sarb);
883	vcc_data->sarb = NULL;
884
885	kfree(vcc_data);
886	vcc->dev_data = NULL;
887
888	vcc->vpi = ATM_VPI_UNSPEC;
889	vcc->vci = ATM_VCI_UNSPEC;
890	clear_bit(ATM_VF_READY, &vcc->flags);
891	clear_bit(ATM_VF_PARTIAL, &vcc->flags);
892	clear_bit(ATM_VF_ADDR, &vcc->flags);
893
894	mutex_unlock(&instance->serialize);
895}
896
897static int usbatm_atm_ioctl(struct atm_dev *atm_dev, unsigned int cmd,
898			  void __user *arg)
899{
900	struct usbatm_data *instance = atm_dev->dev_data;
901
902	if (!instance || instance->disconnected)
903		return -ENODEV;
904
905	switch (cmd) {
906	case ATM_QUERYLOOP:
907		return put_user(ATM_LM_NONE, (int __user *)arg) ? -EFAULT : 0;
908	default:
909		return -ENOIOCTLCMD;
910	}
911}
912
913static int usbatm_atm_init(struct usbatm_data *instance)
914{
915	struct atm_dev *atm_dev;
916	int ret, i;
917
918	/* ATM init.  The ATM initialization scheme suffers from an intrinsic race
919	 * condition: callbacks we register can be executed at once, before we have
920	 * initialized the struct atm_dev.  To protect against this, all callbacks
921	 * abort if atm_dev->dev_data is NULL. */
922	atm_dev = atm_dev_register(instance->driver_name,
923				   &instance->usb_intf->dev, &usbatm_atm_devops,
924				   -1, NULL);
925	if (!atm_dev) {
926		usb_err(instance, "%s: failed to register ATM device!\n", __func__);
927		return -1;
928	}
929
930	instance->atm_dev = atm_dev;
931
932	atm_dev->ci_range.vpi_bits = ATM_CI_MAX;
933	atm_dev->ci_range.vci_bits = ATM_CI_MAX;
934	atm_dev->signal = ATM_PHY_SIG_UNKNOWN;
935
936	/* temp init ATM device, set to 128kbit */
937	atm_dev->link_rate = 128 * 1000 / 424;
938
939	if (instance->driver->atm_start && ((ret = instance->driver->atm_start(instance, atm_dev)) < 0)) {
940		atm_err(instance, "%s: atm_start failed: %d!\n", __func__, ret);
941		goto fail;
942	}
943
944	usbatm_get_instance(instance);	/* dropped in usbatm_atm_dev_close */
945
946	/* ready for ATM callbacks */
947	mb();
948	atm_dev->dev_data = instance;
949
950	/* submit all rx URBs */
951	for (i = 0; i < num_rcv_urbs; i++)
952		usbatm_submit_urb(instance->urbs[i]);
953
954	return 0;
955
956 fail:
957	instance->atm_dev = NULL;
958	atm_dev_deregister(atm_dev); /* usbatm_atm_dev_close will eventually be called */
959	return ret;
960}
961
962
963/**********
964**  USB  **
965**********/
966
967static int usbatm_do_heavy_init(void *arg)
968{
969	struct usbatm_data *instance = arg;
970	int ret;
971
972	allow_signal(SIGTERM);
973	complete(&instance->thread_started);
974
975	ret = instance->driver->heavy_init(instance, instance->usb_intf);
976
977	if (!ret)
978		ret = usbatm_atm_init(instance);
979
980	mutex_lock(&instance->serialize);
981	instance->thread = NULL;
982	mutex_unlock(&instance->serialize);
983
984	complete_and_exit(&instance->thread_exited, ret);
985}
986
987static int usbatm_heavy_init(struct usbatm_data *instance)
988{
989	struct task_struct *t;
990
991	t = kthread_create(usbatm_do_heavy_init, instance, "%s",
992			instance->driver->driver_name);
993	if (IS_ERR(t)) {
994		usb_err(instance, "%s: failed to create kernel_thread (%ld)!\n",
995				__func__, PTR_ERR(t));
996		return PTR_ERR(t);
997	}
998
999	instance->thread = t;
1000	wake_up_process(t);
1001	wait_for_completion(&instance->thread_started);
1002
1003	return 0;
1004}
1005
1006static void usbatm_tasklet_schedule(unsigned long data)
1007{
1008	tasklet_schedule((struct tasklet_struct *) data);
1009}
1010
1011static void usbatm_init_channel(struct usbatm_channel *channel)
1012{
1013	spin_lock_init(&channel->lock);
1014	INIT_LIST_HEAD(&channel->list);
1015	channel->delay.function = usbatm_tasklet_schedule;
1016	channel->delay.data = (unsigned long) &channel->tasklet;
1017	init_timer(&channel->delay);
1018}
1019
1020int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id,
1021		     struct usbatm_driver *driver)
1022{
1023	struct device *dev = &intf->dev;
1024	struct usb_device *usb_dev = interface_to_usbdev(intf);
1025	struct usbatm_data *instance;
1026	char *buf;
1027	int error = -ENOMEM;
1028	int i, length;
1029	unsigned int maxpacket, num_packets;
1030
1031	/* instance init */
1032	instance = kzalloc(sizeof(*instance) + sizeof(struct urb *) * (num_rcv_urbs + num_snd_urbs), GFP_KERNEL);
1033	if (!instance) {
1034		dev_err(dev, "%s: no memory for instance data!\n", __func__);
1035		return -ENOMEM;
1036	}
1037
1038	/* public fields */
1039
1040	instance->driver = driver;
1041	strlcpy(instance->driver_name, driver->driver_name,
1042		sizeof(instance->driver_name));
1043
1044	instance->usb_dev = usb_dev;
1045	instance->usb_intf = intf;
1046
1047	buf = instance->description;
1048	length = sizeof(instance->description);
1049
1050	if ((i = usb_string(usb_dev, usb_dev->descriptor.iProduct, buf, length)) < 0)
1051		goto bind;
1052
1053	buf += i;
1054	length -= i;
1055
1056	i = scnprintf(buf, length, " (");
1057	buf += i;
1058	length -= i;
1059
1060	if (length <= 0 || (i = usb_make_path(usb_dev, buf, length)) < 0)
1061		goto bind;
1062
1063	buf += i;
1064	length -= i;
1065
1066	snprintf(buf, length, ")");
1067
1068 bind:
1069	if (driver->bind && (error = driver->bind(instance, intf, id)) < 0) {
1070			dev_err(dev, "%s: bind failed: %d!\n", __func__, error);
1071			goto fail_free;
1072	}
1073
1074	/* private fields */
1075
1076	kref_init(&instance->refcount);		/* dropped in usbatm_usb_disconnect */
1077	mutex_init(&instance->serialize);
1078
1079	instance->thread = NULL;
1080	init_completion(&instance->thread_started);
1081	init_completion(&instance->thread_exited);
1082
1083	INIT_LIST_HEAD(&instance->vcc_list);
1084	skb_queue_head_init(&instance->sndqueue);
1085
1086	usbatm_init_channel(&instance->rx_channel);
1087	usbatm_init_channel(&instance->tx_channel);
1088	tasklet_init(&instance->rx_channel.tasklet, usbatm_rx_process, (unsigned long)instance);
1089	tasklet_init(&instance->tx_channel.tasklet, usbatm_tx_process, (unsigned long)instance);
1090	instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding;
1091	instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding;
1092	instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance;
1093
1094	if ((instance->flags & UDSL_USE_ISOC) && driver->isoc_in)
1095		instance->rx_channel.endpoint = usb_rcvisocpipe(usb_dev, driver->isoc_in);
1096	else
1097		instance->rx_channel.endpoint = usb_rcvbulkpipe(usb_dev, driver->bulk_in);
1098
1099	instance->tx_channel.endpoint = usb_sndbulkpipe(usb_dev, driver->bulk_out);
1100
1101	/* tx buffer size must be a positive multiple of the stride */
1102	instance->tx_channel.buf_size = max(instance->tx_channel.stride,
1103			snd_buf_bytes - (snd_buf_bytes % instance->tx_channel.stride));
1104
1105	/* rx buffer size must be a positive multiple of the endpoint maxpacket */
1106	maxpacket = usb_maxpacket(usb_dev, instance->rx_channel.endpoint, 0);
1107
1108	if ((maxpacket < 1) || (maxpacket > UDSL_MAX_BUF_SIZE)) {
1109		dev_err(dev, "%s: invalid endpoint %02x!\n", __func__,
1110				usb_pipeendpoint(instance->rx_channel.endpoint));
1111		error = -EINVAL;
1112		goto fail_unbind;
1113	}
1114
1115	num_packets = max(1U, (rcv_buf_bytes + maxpacket / 2) / maxpacket); /* round */
1116
1117	if (num_packets * maxpacket > UDSL_MAX_BUF_SIZE)
1118		num_packets--;
1119
1120	instance->rx_channel.buf_size = num_packets * maxpacket;
1121	instance->rx_channel.packet_size = maxpacket;
1122
1123	for (i = 0; i < 2; i++) {
1124		struct usbatm_channel *channel = i ?
1125			&instance->tx_channel : &instance->rx_channel;
1126
1127		dev_dbg(dev, "%s: using %d byte buffer for %s channel 0x%p\n",
1128			__func__, channel->buf_size, i ? "tx" : "rx", channel);
1129	}
1130
1131	/* initialize urbs */
1132
1133	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1134		u8 *buffer;
1135		struct usbatm_channel *channel = i < num_rcv_urbs ?
1136			&instance->rx_channel : &instance->tx_channel;
1137		struct urb *urb;
1138		unsigned int iso_packets = usb_pipeisoc(channel->endpoint) ? channel->buf_size / channel->packet_size : 0;
1139
1140		urb = usb_alloc_urb(iso_packets, GFP_KERNEL);
1141		if (!urb) {
1142			dev_err(dev, "%s: no memory for urb %d!\n", __func__, i);
1143			error = -ENOMEM;
1144			goto fail_unbind;
1145		}
1146
1147		instance->urbs[i] = urb;
1148
1149		/* zero the tx padding to avoid leaking information */
1150		buffer = kzalloc(channel->buf_size, GFP_KERNEL);
1151		if (!buffer) {
1152			dev_err(dev, "%s: no memory for buffer %d!\n", __func__, i);
1153			error = -ENOMEM;
1154			goto fail_unbind;
1155		}
1156
1157		usb_fill_bulk_urb(urb, instance->usb_dev, channel->endpoint,
1158				  buffer, channel->buf_size, usbatm_complete, channel);
1159		if (iso_packets) {
1160			int j;
1161			urb->interval = 1;
1162			urb->transfer_flags = URB_ISO_ASAP;
1163			urb->number_of_packets = iso_packets;
1164			for (j = 0; j < iso_packets; j++) {
1165				urb->iso_frame_desc[j].offset = channel->packet_size * j;
1166				urb->iso_frame_desc[j].length = channel->packet_size;
1167			}
1168		}
1169
1170		/* put all tx URBs on the list of spares */
1171		if (i >= num_rcv_urbs)
1172			list_add_tail(&urb->urb_list, &channel->list);
1173
1174		vdbg(&intf->dev, "%s: alloced buffer 0x%p buf size %u urb 0x%p",
1175		     __func__, urb->transfer_buffer, urb->transfer_buffer_length, urb);
1176	}
1177
1178	instance->cached_vpi = ATM_VPI_UNSPEC;
1179	instance->cached_vci = ATM_VCI_UNSPEC;
1180	instance->cell_buf = kmalloc(instance->rx_channel.stride, GFP_KERNEL);
1181
1182	if (!instance->cell_buf) {
1183		dev_err(dev, "%s: no memory for cell buffer!\n", __func__);
1184		error = -ENOMEM;
1185		goto fail_unbind;
1186	}
1187
1188	if (!(instance->flags & UDSL_SKIP_HEAVY_INIT) && driver->heavy_init) {
1189		error = usbatm_heavy_init(instance);
1190	} else {
1191		complete(&instance->thread_exited);	/* pretend that heavy_init was run */
1192		error = usbatm_atm_init(instance);
1193	}
1194
1195	if (error < 0)
1196		goto fail_unbind;
1197
1198	usb_get_dev(usb_dev);
1199	usb_set_intfdata(intf, instance);
1200
1201	return 0;
1202
1203 fail_unbind:
1204	if (instance->driver->unbind)
1205		instance->driver->unbind(instance, intf);
1206 fail_free:
1207	kfree(instance->cell_buf);
1208
1209	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1210		if (instance->urbs[i])
1211			kfree(instance->urbs[i]->transfer_buffer);
1212		usb_free_urb(instance->urbs[i]);
1213	}
1214
1215	kfree(instance);
1216
1217	return error;
1218}
1219EXPORT_SYMBOL_GPL(usbatm_usb_probe);
1220
1221void usbatm_usb_disconnect(struct usb_interface *intf)
1222{
1223	struct device *dev = &intf->dev;
1224	struct usbatm_data *instance = usb_get_intfdata(intf);
1225	struct usbatm_vcc_data *vcc_data;
1226	int i;
1227
1228	if (!instance) {
1229		dev_dbg(dev, "%s: NULL instance!\n", __func__);
1230		return;
1231	}
1232
1233	usb_set_intfdata(intf, NULL);
1234
1235	mutex_lock(&instance->serialize);
1236	instance->disconnected = 1;
1237	if (instance->thread != NULL)
1238		send_sig(SIGTERM, instance->thread, 1);
1239	mutex_unlock(&instance->serialize);
1240
1241	wait_for_completion(&instance->thread_exited);
1242
1243	mutex_lock(&instance->serialize);
1244	list_for_each_entry(vcc_data, &instance->vcc_list, list)
1245		vcc_release_async(vcc_data->vcc, -EPIPE);
1246	mutex_unlock(&instance->serialize);
1247
1248	tasklet_disable(&instance->rx_channel.tasklet);
1249	tasklet_disable(&instance->tx_channel.tasklet);
1250
1251	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++)
1252		usb_kill_urb(instance->urbs[i]);
1253
1254	del_timer_sync(&instance->rx_channel.delay);
1255	del_timer_sync(&instance->tx_channel.delay);
1256
1257	/* turn usbatm_[rt]x_process into something close to a no-op */
1258	/* no need to take the spinlock */
1259	INIT_LIST_HEAD(&instance->rx_channel.list);
1260	INIT_LIST_HEAD(&instance->tx_channel.list);
1261
1262	tasklet_enable(&instance->rx_channel.tasklet);
1263	tasklet_enable(&instance->tx_channel.tasklet);
1264
1265	if (instance->atm_dev && instance->driver->atm_stop)
1266		instance->driver->atm_stop(instance, instance->atm_dev);
1267
1268	if (instance->driver->unbind)
1269		instance->driver->unbind(instance, intf);
1270
1271	instance->driver_data = NULL;
1272
1273	for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) {
1274		kfree(instance->urbs[i]->transfer_buffer);
1275		usb_free_urb(instance->urbs[i]);
1276	}
1277
1278	kfree(instance->cell_buf);
1279
1280	/* ATM finalize */
1281	if (instance->atm_dev) {
1282		atm_dev_deregister(instance->atm_dev);
1283		instance->atm_dev = NULL;
1284	}
1285
1286	usbatm_put_instance(instance);	/* taken in usbatm_usb_probe */
1287}
1288EXPORT_SYMBOL_GPL(usbatm_usb_disconnect);
1289
1290
1291/***********
1292**  init  **
1293***********/
1294
1295static int __init usbatm_usb_init(void)
1296{
1297	if (sizeof(struct usbatm_control) > FIELD_SIZEOF(struct sk_buff, cb)) {
1298		printk(KERN_ERR "%s unusable with this kernel!\n", usbatm_driver_name);
1299		return -EIO;
1300	}
1301
1302	if ((num_rcv_urbs > UDSL_MAX_RCV_URBS)
1303	    || (num_snd_urbs > UDSL_MAX_SND_URBS)
1304	    || (rcv_buf_bytes < 1)
1305	    || (rcv_buf_bytes > UDSL_MAX_BUF_SIZE)
1306	    || (snd_buf_bytes < 1)
1307	    || (snd_buf_bytes > UDSL_MAX_BUF_SIZE))
1308		return -EINVAL;
1309
1310	return 0;
1311}
1312module_init(usbatm_usb_init);
1313
1314static void __exit usbatm_usb_exit(void)
1315{
1316}
1317module_exit(usbatm_usb_exit);
1318
1319MODULE_AUTHOR(DRIVER_AUTHOR);
1320MODULE_DESCRIPTION(DRIVER_DESC);
1321MODULE_LICENSE("GPL");
1322MODULE_VERSION(DRIVER_VERSION);
1323
1324/************
1325**  debug  **
1326************/
1327
1328#ifdef VERBOSE_DEBUG
1329static int usbatm_print_packet(struct usbatm_data *instance,
1330			       const unsigned char *data, int len)
1331{
1332	unsigned char buffer[256];
1333	int i = 0, j = 0;
1334
1335	for (i = 0; i < len;) {
1336		buffer[0] = '\0';
1337		sprintf(buffer, "%.3d :", i);
1338		for (j = 0; (j < 16) && (i < len); j++, i++)
1339			sprintf(buffer, "%s %2.2x", buffer, data[i]);
1340		dev_dbg(&instance->usb_intf->dev, "%s", buffer);
1341	}
1342	return i;
1343}
1344#endif
1345