Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
/*****************************************************************************
*
* Filename:      ks959-sir.c
* Version:       0.1.2
* Description:   Irda KingSun KS-959 USB Dongle
* Status:        Experimental
* Author:        Alex Villacís Lasso <a_villacis@palosanto.com>
*         with help from Domen Puncer <domen@coderock.org>
*
*    Based on stir4200, mcs7780, kingsun-sir drivers.
*
*    This program is free software; you can redistribute it and/or modify
*    it under the terms of the GNU General Public License as published by
*    the Free Software Foundation; either version 2 of the License.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU General Public License for more details.
*
*    You should have received a copy of the GNU General Public License
*    along with this program; if not, write to the Free Software
*    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*****************************************************************************/

/*
 * Following is my most current (2007-07-17) understanding of how the Kingsun
 * KS-959 dongle is supposed to work. This information was deduced by
 * reverse-engineering and examining the USB traffic captured with USBSnoopy
 * from the WinXP driver. Feel free to update here as more of the dongle is
 * known.
 *
 * My most sincere thanks must go to Domen Puncer <domen@coderock.org> for
 * invaluable help in cracking the obfuscation and padding required for this
 * dongle.
 *
 * General: This dongle exposes one interface with one interrupt IN endpoint.
 * However, the interrupt endpoint is NOT used at all for this dongle. Instead,
 * this dongle uses control transfers for everything, including sending and
 * receiving the IrDA frame data. Apparently the interrupt endpoint is just a
 * dummy to ensure the dongle has a valid interface to present to the PC.And I
 * thought the DonShine dongle was weird... In addition, this dongle uses
 * obfuscation (?!?!), applied at the USB level, to hide the traffic, both sent
 * and received, from the dongle. I call it obfuscation because the XOR keying
 * and padding required to produce an USB traffic acceptable for the dongle can
 * not be explained by any other technical requirement.
 *
 * Transmission: To transmit an IrDA frame, the driver must prepare a control
 * URB with the following as a setup packet:
 *    bRequestType    USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE
 *    bRequest        0x09
 *    wValue          <length of valid data before padding, little endian>
 *    wIndex          0x0000
 *    wLength         <length of padded data>
 * The payload packet must be manually wrapped and escaped (as in stir4200.c),
 * then padded and obfuscated before being sent. Both padding and obfuscation
 * are implemented in the procedure obfuscate_tx_buffer(). Suffice to say, the
 * designer/programmer of the dongle used his name as a source for the
 * obfuscation. WTF?!
 * Apparently the dongle cannot handle payloads larger than 256 bytes. The
 * driver has to perform fragmentation in order to send anything larger than
 * this limit.
 *
 * Reception: To receive data, the driver must poll the dongle regularly (like
 * kingsun-sir.c) with control URBs and the following as a setup packet:
 *    bRequestType    USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE
 *    bRequest        0x01
 *    wValue          0x0200
 *    wIndex          0x0000
 *    wLength         0x0800 (size of available buffer)
 * If there is data to be read, it will be returned as the response payload.
 * This data is (apparently) not padded, but it is obfuscated. To de-obfuscate
 * it, the driver must XOR every byte, in sequence, with a value that starts at
 * 1 and is incremented with each byte processed, and then with 0x55. The value
 * incremented with each byte processed overflows as an unsigned char. The
 * resulting bytes form a wrapped SIR frame that is unwrapped and unescaped
 * as in stir4200.c The incremented value is NOT reset with each frame, but is
 * kept across the entire session with the dongle. Also, the dongle inserts an
 * extra garbage byte with value 0x95 (after decoding) every 0xff bytes, which
 * must be skipped.
 *
 * Speed change: To change the speed of the dongle, the driver prepares a
 * control URB with the following as a setup packet:
 *    bRequestType    USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE
 *    bRequest        0x09
 *    wValue          0x0200
 *    wIndex          0x0001
 *    wLength         0x0008 (length of the payload)
 * The payload is a 8-byte record, apparently identical to the one used in
 * drivers/usb/serial/cypress_m8.c to change speed:
 *     __u32 baudSpeed;
 *    unsigned int dataBits : 2;    // 0 - 5 bits 3 - 8 bits
 *    unsigned int : 1;
 *    unsigned int stopBits : 1;
 *    unsigned int parityEnable : 1;
 *    unsigned int parityType : 1;
 *    unsigned int : 1;
 *    unsigned int reset : 1;
 *    unsigned char reserved[3];    // set to 0
 *
 * For now only SIR speeds have been observed with this dongle. Therefore,
 * nothing is known on what changes (if any) must be done to frame wrapping /
 * unwrapping for higher than SIR speeds. This driver assumes no change is
 * necessary and announces support for all the way to 57600 bps. Although the
 * package announces support for up to 4MBps, tests with a Sony Ericcson K300
 * phone show corruption when receiving large frames at 115200 bps, the highest
 * speed announced by the phone. However, transmission at 115200 bps is OK. Go
 * figure. Since I don't know whether the phone or the dongle is at fault, max
 * announced speed is 57600 bps until someone produces a device that can run
 * at higher speeds with this dongle.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/crc32.h>

#include <asm/unaligned.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>

#include <net/irda/irda.h>
#include <net/irda/wrapper.h>
#include <net/irda/crc.h>

#define KS959_VENDOR_ID 0x07d0
#define KS959_PRODUCT_ID 0x4959

/* These are the currently known USB ids */
static struct usb_device_id dongles[] = {
	/* KingSun Co,Ltd  IrDA/USB Bridge */
	{USB_DEVICE(KS959_VENDOR_ID, KS959_PRODUCT_ID)},
	{}
};

MODULE_DEVICE_TABLE(usb, dongles);

#define KINGSUN_MTT 0x07
#define KINGSUN_REQ_RECV 0x01
#define KINGSUN_REQ_SEND 0x09

#define KINGSUN_RCV_FIFO_SIZE    2048	/* Max length we can receive */
#define KINGSUN_SND_FIFO_SIZE    2048	/* Max packet we can send */
#define KINGSUN_SND_PACKET_SIZE    256	/* Max packet dongle can handle */

struct ks959_speedparams {
	__le32 baudrate;	/* baud rate, little endian */
	__u8 flags;
	__u8 reserved[3];
} __packed;

#define KS_DATA_5_BITS 0x00
#define KS_DATA_6_BITS 0x01
#define KS_DATA_7_BITS 0x02
#define KS_DATA_8_BITS 0x03

#define KS_STOP_BITS_1 0x00
#define KS_STOP_BITS_2 0x08

#define KS_PAR_DISABLE    0x00
#define KS_PAR_EVEN    0x10
#define KS_PAR_ODD    0x30
#define KS_RESET    0x80

struct ks959_cb {
	struct usb_device *usbdev;	/* init: probe_irda */
	struct net_device *netdev;	/* network layer */
	struct irlap_cb *irlap;	/* The link layer we are binded to */

	struct qos_info qos;

	struct usb_ctrlrequest *tx_setuprequest;
	struct urb *tx_urb;
	__u8 *tx_buf_clear;
	unsigned int tx_buf_clear_used;
	unsigned int tx_buf_clear_sent;
	__u8 *tx_buf_xored;

	struct usb_ctrlrequest *rx_setuprequest;
	struct urb *rx_urb;
	__u8 *rx_buf;
	__u8 rx_variable_xormask;
	iobuff_t rx_unwrap_buff;

	struct usb_ctrlrequest *speed_setuprequest;
	struct urb *speed_urb;
	struct ks959_speedparams speedparams;
	unsigned int new_speed;

	spinlock_t lock;
	int receiving;
};

/* Procedure to perform the obfuscation/padding expected by the dongle
 *
 * buf_cleartext    (IN) Cleartext version of the IrDA frame to transmit
 * len_cleartext    (IN) Length of the cleartext version of IrDA frame
 * buf_xoredtext    (OUT) Obfuscated version of frame built by proc
 * len_maxbuf        (OUT) Maximum space available at buf_xoredtext
 *
 * (return)         length of obfuscated frame with padding
 *
 * If not enough space (as indicated by len_maxbuf vs. required padding),
 * zero is returned
 *
 * The value of lookup_string is actually a required portion of the algorithm.
 * Seems the designer of the dongle wanted to state who exactly is responsible
 * for implementing obfuscation. Send your best (or other) wishes to him ]:-)
 */
static unsigned int obfuscate_tx_buffer(const __u8 * buf_cleartext,
					unsigned int len_cleartext,
					__u8 * buf_xoredtext,
					unsigned int len_maxbuf)
{
	unsigned int len_xoredtext;

	/* Calculate required length with padding, check for necessary space */
	len_xoredtext = ((len_cleartext + 7) & ~0x7) + 0x10;
	if (len_xoredtext <= len_maxbuf) {
		static const __u8 lookup_string[] = "wangshuofei19710";
		__u8 xor_mask;

		/* Unlike the WinXP driver, we *do* clear out the padding */
		memset(buf_xoredtext, 0, len_xoredtext);

		xor_mask = lookup_string[(len_cleartext & 0x0f) ^ 0x06] ^ 0x55;

		while (len_cleartext-- > 0) {
			*buf_xoredtext++ = *buf_cleartext++ ^ xor_mask;
		}
	} else {
		len_xoredtext = 0;
	}
	return len_xoredtext;
}

/* Callback transmission routine */
static void ks959_speed_irq(struct urb *urb)
{
	/* unlink, shutdown, unplug, other nasties */
	if (urb->status != 0) {
		dev_err(&urb->dev->dev,
			"ks959_speed_irq: urb asynchronously failed - %d\n",
			urb->status);
	}
}

/* Send a control request to change speed of the dongle */
static int ks959_change_speed(struct ks959_cb *kingsun, unsigned speed)
{
	static unsigned int supported_speeds[] = { 2400, 9600, 19200, 38400,
		57600, 115200, 576000, 1152000, 4000000, 0
	};
	int err;
	unsigned int i;

	if (kingsun->speed_setuprequest == NULL || kingsun->speed_urb == NULL)
		return -ENOMEM;

	/* Check that requested speed is among the supported ones */
	for (i = 0; supported_speeds[i] && supported_speeds[i] != speed; i++) ;
	if (supported_speeds[i] == 0)
		return -EOPNOTSUPP;

	memset(&(kingsun->speedparams), 0, sizeof(struct ks959_speedparams));
	kingsun->speedparams.baudrate = cpu_to_le32(speed);
	kingsun->speedparams.flags = KS_DATA_8_BITS;

	/* speed_setuprequest pre-filled in ks959_probe */
	usb_fill_control_urb(kingsun->speed_urb, kingsun->usbdev,
			     usb_sndctrlpipe(kingsun->usbdev, 0),
			     (unsigned char *)kingsun->speed_setuprequest,
			     &(kingsun->speedparams),
			     sizeof(struct ks959_speedparams), ks959_speed_irq,
			     kingsun);
	kingsun->speed_urb->status = 0;
	err = usb_submit_urb(kingsun->speed_urb, GFP_ATOMIC);

	return err;
}

/* Submit one fragment of an IrDA frame to the dongle */
static void ks959_send_irq(struct urb *urb);
static int ks959_submit_tx_fragment(struct ks959_cb *kingsun)
{
	unsigned int padlen;
	unsigned int wraplen;
	int ret;

	/* Check whether current plaintext can produce a padded buffer that fits
	   within the range handled by the dongle */
	wraplen = (KINGSUN_SND_PACKET_SIZE & ~0x7) - 0x10;
	if (wraplen > kingsun->tx_buf_clear_used)
		wraplen = kingsun->tx_buf_clear_used;

	/* Perform dongle obfuscation. Also remove the portion of the frame that
	   was just obfuscated and will now be sent to the dongle. */
	padlen = obfuscate_tx_buffer(kingsun->tx_buf_clear, wraplen,
				     kingsun->tx_buf_xored,
				     KINGSUN_SND_PACKET_SIZE);

	/* Calculate how much data can be transmitted in this urb */
	kingsun->tx_setuprequest->wValue = cpu_to_le16(wraplen);
	kingsun->tx_setuprequest->wLength = cpu_to_le16(padlen);
	/* Rest of the fields were filled in ks959_probe */
	usb_fill_control_urb(kingsun->tx_urb, kingsun->usbdev,
			     usb_sndctrlpipe(kingsun->usbdev, 0),
			     (unsigned char *)kingsun->tx_setuprequest,
			     kingsun->tx_buf_xored, padlen,
			     ks959_send_irq, kingsun);
	kingsun->tx_urb->status = 0;
	ret = usb_submit_urb(kingsun->tx_urb, GFP_ATOMIC);

	/* Remember how much data was sent, in order to update at callback */
	kingsun->tx_buf_clear_sent = (ret == 0) ? wraplen : 0;
	return ret;
}

/* Callback transmission routine */
static void ks959_send_irq(struct urb *urb)
{
	struct ks959_cb *kingsun = urb->context;
	struct net_device *netdev = kingsun->netdev;
	int ret = 0;

	/* in process of stopping, just drop data */
	if (!netif_running(kingsun->netdev)) {
		dev_err(&kingsun->usbdev->dev,
			"ks959_send_irq: Network not running!\n");
		return;
	}

	/* unlink, shutdown, unplug, other nasties */
	if (urb->status != 0) {
		dev_err(&kingsun->usbdev->dev,
			"ks959_send_irq: urb asynchronously failed - %d\n",
			urb->status);
		return;
	}

	if (kingsun->tx_buf_clear_used > 0) {
		/* Update data remaining to be sent */
		if (kingsun->tx_buf_clear_sent < kingsun->tx_buf_clear_used) {
			memmove(kingsun->tx_buf_clear,
				kingsun->tx_buf_clear +
				kingsun->tx_buf_clear_sent,
				kingsun->tx_buf_clear_used -
				kingsun->tx_buf_clear_sent);
		}
		kingsun->tx_buf_clear_used -= kingsun->tx_buf_clear_sent;
		kingsun->tx_buf_clear_sent = 0;

		if (kingsun->tx_buf_clear_used > 0) {
			/* There is more data to be sent */
			if ((ret = ks959_submit_tx_fragment(kingsun)) != 0) {
				dev_err(&kingsun->usbdev->dev,
					"ks959_send_irq: failed tx_urb submit: %d\n",
					ret);
				switch (ret) {
				case -ENODEV:
				case -EPIPE:
					break;
				default:
					netdev->stats.tx_errors++;
					netif_start_queue(netdev);
				}
			}
		} else {
			/* All data sent, send next speed && wake network queue */
			if (kingsun->new_speed != -1 &&
			    cpu_to_le32(kingsun->new_speed) !=
			    kingsun->speedparams.baudrate)
				ks959_change_speed(kingsun, kingsun->new_speed);

			netif_wake_queue(netdev);
		}
	}
}

/*
 * Called from net/core when new frame is available.
 */
static netdev_tx_t ks959_hard_xmit(struct sk_buff *skb,
					 struct net_device *netdev)
{
	struct ks959_cb *kingsun;
	unsigned int wraplen;
	int ret = 0;

	netif_stop_queue(netdev);

	/* the IRDA wrapping routines don't deal with non linear skb */
	SKB_LINEAR_ASSERT(skb);

	kingsun = netdev_priv(netdev);

	spin_lock(&kingsun->lock);
	kingsun->new_speed = irda_get_next_speed(skb);

	/* Append data to the end of whatever data remains to be transmitted */
	wraplen =
	    async_wrap_skb(skb, kingsun->tx_buf_clear, KINGSUN_SND_FIFO_SIZE);
	kingsun->tx_buf_clear_used = wraplen;

	if ((ret = ks959_submit_tx_fragment(kingsun)) != 0) {
		dev_err(&kingsun->usbdev->dev,
			"ks959_hard_xmit: failed tx_urb submit: %d\n", ret);
		switch (ret) {
		case -ENODEV:
		case -EPIPE:
			break;
		default:
			netdev->stats.tx_errors++;
			netif_start_queue(netdev);
		}
	} else {
		netdev->stats.tx_packets++;
		netdev->stats.tx_bytes += skb->len;

	}

	dev_kfree_skb(skb);
	spin_unlock(&kingsun->lock);

	return NETDEV_TX_OK;
}

/* Receive callback function */
static void ks959_rcv_irq(struct urb *urb)
{
	struct ks959_cb *kingsun = urb->context;
	int ret;

	/* in process of stopping, just drop data */
	if (!netif_running(kingsun->netdev)) {
		kingsun->receiving = 0;
		return;
	}

	/* unlink, shutdown, unplug, other nasties */
	if (urb->status != 0) {
		dev_err(&kingsun->usbdev->dev,
			"kingsun_rcv_irq: urb asynchronously failed - %d\n",
			urb->status);
		kingsun->receiving = 0;
		return;
	}

	if (urb->actual_length > 0) {
		__u8 *bytes = urb->transfer_buffer;
		unsigned int i;

		for (i = 0; i < urb->actual_length; i++) {
			/* De-obfuscation implemented here: variable portion of
			   xormask is incremented, and then used with the encoded
			   byte for the XOR. The result of the operation is used
			   to unwrap the SIR frame. */
			kingsun->rx_variable_xormask++;
			bytes[i] =
			    bytes[i] ^ kingsun->rx_variable_xormask ^ 0x55u;

			/* rx_variable_xormask doubles as an index counter so we
			   can skip the byte at 0xff (wrapped around to 0).
			 */
			if (kingsun->rx_variable_xormask != 0) {
				async_unwrap_char(kingsun->netdev,
						  &kingsun->netdev->stats,
						  &kingsun->rx_unwrap_buff,
						  bytes[i]);
			}
		}
		kingsun->receiving =
		    (kingsun->rx_unwrap_buff.state != OUTSIDE_FRAME) ? 1 : 0;
	}

	/* This urb has already been filled in kingsun_net_open. Setup
	   packet must be re-filled, but it is assumed that urb keeps the
	   pointer to the initial setup packet, as well as the payload buffer.
	   Setup packet is already pre-filled at ks959_probe.
	 */
	urb->status = 0;
	ret = usb_submit_urb(urb, GFP_ATOMIC);
}

/*
 * Function kingsun_net_open (dev)
 *
 *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
 */
static int ks959_net_open(struct net_device *netdev)
{
	struct ks959_cb *kingsun = netdev_priv(netdev);
	int err = -ENOMEM;
	char hwname[16];

	/* At this point, urbs are NULL, and skb is NULL (see kingsun_probe) */
	kingsun->receiving = 0;

	/* Initialize for SIR to copy data directly into skb.  */
	kingsun->rx_unwrap_buff.in_frame = FALSE;
	kingsun->rx_unwrap_buff.state = OUTSIDE_FRAME;
	kingsun->rx_unwrap_buff.truesize = IRDA_SKB_MAX_MTU;
	kingsun->rx_unwrap_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
	if (!kingsun->rx_unwrap_buff.skb)
		goto free_mem;

	skb_reserve(kingsun->rx_unwrap_buff.skb, 1);
	kingsun->rx_unwrap_buff.head = kingsun->rx_unwrap_buff.skb->data;

	kingsun->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!kingsun->rx_urb)
		goto free_mem;

	kingsun->tx_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!kingsun->tx_urb)
		goto free_mem;

	kingsun->speed_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!kingsun->speed_urb)
		goto free_mem;

	/* Initialize speed for dongle */
	kingsun->new_speed = 9600;
	err = ks959_change_speed(kingsun, 9600);
	if (err < 0)
		goto free_mem;

	/*
	 * Now that everything should be initialized properly,
	 * Open new IrLAP layer instance to take care of us...
	 */
	sprintf(hwname, "usb#%d", kingsun->usbdev->devnum);
	kingsun->irlap = irlap_open(netdev, &kingsun->qos, hwname);
	if (!kingsun->irlap) {
		err = -ENOMEM;
		dev_err(&kingsun->usbdev->dev, "irlap_open failed\n");
		goto free_mem;
	}

	/* Start reception. Setup request already pre-filled in ks959_probe */
	usb_fill_control_urb(kingsun->rx_urb, kingsun->usbdev,
			     usb_rcvctrlpipe(kingsun->usbdev, 0),
			     (unsigned char *)kingsun->rx_setuprequest,
			     kingsun->rx_buf, KINGSUN_RCV_FIFO_SIZE,
			     ks959_rcv_irq, kingsun);
	kingsun->rx_urb->status = 0;
	err = usb_submit_urb(kingsun->rx_urb, GFP_KERNEL);
	if (err) {
		dev_err(&kingsun->usbdev->dev,
			"first urb-submit failed: %d\n", err);
		goto close_irlap;
	}

	netif_start_queue(netdev);

	/* Situation at this point:
	   - all work buffers allocated
	   - urbs allocated and ready to fill
	   - max rx packet known (in max_rx)
	   - unwrap state machine initialized, in state outside of any frame
	   - receive request in progress
	   - IrLAP layer started, about to hand over packets to send
	 */

	return 0;

      close_irlap:
	irlap_close(kingsun->irlap);
      free_mem:
	usb_free_urb(kingsun->speed_urb);
	kingsun->speed_urb = NULL;
	usb_free_urb(kingsun->tx_urb);
	kingsun->tx_urb = NULL;
	usb_free_urb(kingsun->rx_urb);
	kingsun->rx_urb = NULL;
	if (kingsun->rx_unwrap_buff.skb) {
		kfree_skb(kingsun->rx_unwrap_buff.skb);
		kingsun->rx_unwrap_buff.skb = NULL;
		kingsun->rx_unwrap_buff.head = NULL;
	}
	return err;
}

/*
 * Function kingsun_net_close (kingsun)
 *
 *    Network device is taken down. Usually this is done by
 *    "ifconfig irda0 down"
 */
static int ks959_net_close(struct net_device *netdev)
{
	struct ks959_cb *kingsun = netdev_priv(netdev);

	/* Stop transmit processing */
	netif_stop_queue(netdev);

	/* Mop up receive && transmit urb's */
	usb_kill_urb(kingsun->tx_urb);
	usb_free_urb(kingsun->tx_urb);
	kingsun->tx_urb = NULL;

	usb_kill_urb(kingsun->speed_urb);
	usb_free_urb(kingsun->speed_urb);
	kingsun->speed_urb = NULL;

	usb_kill_urb(kingsun->rx_urb);
	usb_free_urb(kingsun->rx_urb);
	kingsun->rx_urb = NULL;

	kfree_skb(kingsun->rx_unwrap_buff.skb);
	kingsun->rx_unwrap_buff.skb = NULL;
	kingsun->rx_unwrap_buff.head = NULL;
	kingsun->rx_unwrap_buff.in_frame = FALSE;
	kingsun->rx_unwrap_buff.state = OUTSIDE_FRAME;
	kingsun->receiving = 0;

	/* Stop and remove instance of IrLAP */
	if (kingsun->irlap)
		irlap_close(kingsun->irlap);

	kingsun->irlap = NULL;

	return 0;
}

/*
 * IOCTLs : Extra out-of-band network commands...
 */
static int ks959_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
{
	struct if_irda_req *irq = (struct if_irda_req *)rq;
	struct ks959_cb *kingsun = netdev_priv(netdev);
	int ret = 0;

	switch (cmd) {
	case SIOCSBANDWIDTH:	/* Set bandwidth */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		/* Check if the device is still there */
		if (netif_device_present(kingsun->netdev))
			return ks959_change_speed(kingsun, irq->ifr_baudrate);
		break;

	case SIOCSMEDIABUSY:	/* Set media busy */
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		/* Check if the IrDA stack is still there */
		if (netif_running(kingsun->netdev))
			irda_device_set_media_busy(kingsun->netdev, TRUE);
		break;

	case SIOCGRECEIVING:
		/* Only approximately true */
		irq->ifr_receiving = kingsun->receiving;
		break;

	default:
		ret = -EOPNOTSUPP;
	}

	return ret;
}

static const struct net_device_ops ks959_ops = {
	.ndo_start_xmit	= ks959_hard_xmit,
	.ndo_open	= ks959_net_open,
	.ndo_stop	= ks959_net_close,
	.ndo_do_ioctl	= ks959_net_ioctl,
};
/*
 * This routine is called by the USB subsystem for each new device
 * in the system. We need to check if the device is ours, and in
 * this case start handling it.
 */
static int ks959_probe(struct usb_interface *intf,
		       const struct usb_device_id *id)
{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct ks959_cb *kingsun = NULL;
	struct net_device *net = NULL;
	int ret = -ENOMEM;

	/* Allocate network device container. */
	net = alloc_irdadev(sizeof(*kingsun));
	if (!net)
		goto err_out1;

	SET_NETDEV_DEV(net, &intf->dev);
	kingsun = netdev_priv(net);
	kingsun->netdev = net;
	kingsun->usbdev = dev;
	kingsun->irlap = NULL;
	kingsun->tx_setuprequest = NULL;
	kingsun->tx_urb = NULL;
	kingsun->tx_buf_clear = NULL;
	kingsun->tx_buf_xored = NULL;
	kingsun->tx_buf_clear_used = 0;
	kingsun->tx_buf_clear_sent = 0;

	kingsun->rx_setuprequest = NULL;
	kingsun->rx_urb = NULL;
	kingsun->rx_buf = NULL;
	kingsun->rx_variable_xormask = 0;
	kingsun->rx_unwrap_buff.in_frame = FALSE;
	kingsun->rx_unwrap_buff.state = OUTSIDE_FRAME;
	kingsun->rx_unwrap_buff.skb = NULL;
	kingsun->receiving = 0;
	spin_lock_init(&kingsun->lock);

	kingsun->speed_setuprequest = NULL;
	kingsun->speed_urb = NULL;
	kingsun->speedparams.baudrate = 0;

	/* Allocate input buffer */
	kingsun->rx_buf = kmalloc(KINGSUN_RCV_FIFO_SIZE, GFP_KERNEL);
	if (!kingsun->rx_buf)
		goto free_mem;

	/* Allocate input setup packet */
	kingsun->rx_setuprequest =
	    kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
	if (!kingsun->rx_setuprequest)
		goto free_mem;
	kingsun->rx_setuprequest->bRequestType =
	    USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
	kingsun->rx_setuprequest->bRequest = KINGSUN_REQ_RECV;
	kingsun->rx_setuprequest->wValue = cpu_to_le16(0x0200);
	kingsun->rx_setuprequest->wIndex = 0;
	kingsun->rx_setuprequest->wLength = cpu_to_le16(KINGSUN_RCV_FIFO_SIZE);

	/* Allocate output buffer */
	kingsun->tx_buf_clear = kmalloc(KINGSUN_SND_FIFO_SIZE, GFP_KERNEL);
	if (!kingsun->tx_buf_clear)
		goto free_mem;
	kingsun->tx_buf_xored = kmalloc(KINGSUN_SND_PACKET_SIZE, GFP_KERNEL);
	if (!kingsun->tx_buf_xored)
		goto free_mem;

	/* Allocate and initialize output setup packet */
	kingsun->tx_setuprequest =
	    kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
	if (!kingsun->tx_setuprequest)
		goto free_mem;
	kingsun->tx_setuprequest->bRequestType =
	    USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
	kingsun->tx_setuprequest->bRequest = KINGSUN_REQ_SEND;
	kingsun->tx_setuprequest->wValue = 0;
	kingsun->tx_setuprequest->wIndex = 0;
	kingsun->tx_setuprequest->wLength = 0;

	/* Allocate and initialize speed setup packet */
	kingsun->speed_setuprequest =
	    kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
	if (!kingsun->speed_setuprequest)
		goto free_mem;
	kingsun->speed_setuprequest->bRequestType =
	    USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
	kingsun->speed_setuprequest->bRequest = KINGSUN_REQ_SEND;
	kingsun->speed_setuprequest->wValue = cpu_to_le16(0x0200);
	kingsun->speed_setuprequest->wIndex = cpu_to_le16(0x0001);
	kingsun->speed_setuprequest->wLength =
	    cpu_to_le16(sizeof(struct ks959_speedparams));

	printk(KERN_INFO "KingSun KS-959 IRDA/USB found at address %d, "
	       "Vendor: %x, Product: %x\n",
	       dev->devnum, le16_to_cpu(dev->descriptor.idVendor),
	       le16_to_cpu(dev->descriptor.idProduct));

	/* Initialize QoS for this device */
	irda_init_max_qos_capabilies(&kingsun->qos);

	/* Baud rates known to be supported. Please uncomment if devices (other
	   than a SonyEriccson K300 phone) can be shown to support higher speed
	   with this dongle.
	 */
	kingsun->qos.baud_rate.bits =
	    IR_2400 | IR_9600 | IR_19200 | IR_38400 | IR_57600;
	kingsun->qos.min_turn_time.bits &= KINGSUN_MTT;
	irda_qos_bits_to_value(&kingsun->qos);

	/* Override the network functions we need to use */
	net->netdev_ops = &ks959_ops;

	ret = register_netdev(net);
	if (ret != 0)
		goto free_mem;

	dev_info(&net->dev, "IrDA: Registered KingSun KS-959 device %s\n",
		 net->name);

	usb_set_intfdata(intf, kingsun);

	/* Situation at this point:
	   - all work buffers allocated
	   - setup requests pre-filled
	   - urbs not allocated, set to NULL
	   - max rx packet known (is KINGSUN_FIFO_SIZE)
	   - unwrap state machine (partially) initialized, but skb == NULL
	 */

	return 0;

      free_mem:
	kfree(kingsun->speed_setuprequest);
	kfree(kingsun->tx_setuprequest);
	kfree(kingsun->tx_buf_xored);
	kfree(kingsun->tx_buf_clear);
	kfree(kingsun->rx_setuprequest);
	kfree(kingsun->rx_buf);
	free_netdev(net);
      err_out1:
	return ret;
}

/*
 * The current device is removed, the USB layer tell us to shut it down...
 */
static void ks959_disconnect(struct usb_interface *intf)
{
	struct ks959_cb *kingsun = usb_get_intfdata(intf);

	if (!kingsun)
		return;

	unregister_netdev(kingsun->netdev);

	/* Mop up receive && transmit urb's */
	if (kingsun->speed_urb != NULL) {
		usb_kill_urb(kingsun->speed_urb);
		usb_free_urb(kingsun->speed_urb);
		kingsun->speed_urb = NULL;
	}
	if (kingsun->tx_urb != NULL) {
		usb_kill_urb(kingsun->tx_urb);
		usb_free_urb(kingsun->tx_urb);
		kingsun->tx_urb = NULL;
	}
	if (kingsun->rx_urb != NULL) {
		usb_kill_urb(kingsun->rx_urb);
		usb_free_urb(kingsun->rx_urb);
		kingsun->rx_urb = NULL;
	}

	kfree(kingsun->speed_setuprequest);
	kfree(kingsun->tx_setuprequest);
	kfree(kingsun->tx_buf_xored);
	kfree(kingsun->tx_buf_clear);
	kfree(kingsun->rx_setuprequest);
	kfree(kingsun->rx_buf);
	free_netdev(kingsun->netdev);

	usb_set_intfdata(intf, NULL);
}

#ifdef CONFIG_PM
/* USB suspend, so power off the transmitter/receiver */
static int ks959_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct ks959_cb *kingsun = usb_get_intfdata(intf);

	netif_device_detach(kingsun->netdev);
	if (kingsun->speed_urb != NULL)
		usb_kill_urb(kingsun->speed_urb);
	if (kingsun->tx_urb != NULL)
		usb_kill_urb(kingsun->tx_urb);
	if (kingsun->rx_urb != NULL)
		usb_kill_urb(kingsun->rx_urb);
	return 0;
}

/* Coming out of suspend, so reset hardware */
static int ks959_resume(struct usb_interface *intf)
{
	struct ks959_cb *kingsun = usb_get_intfdata(intf);

	if (kingsun->rx_urb != NULL) {
		/* Setup request already filled in ks959_probe */
		usb_submit_urb(kingsun->rx_urb, GFP_KERNEL);
	}
	netif_device_attach(kingsun->netdev);

	return 0;
}
#endif

/*
 * USB device callbacks
 */
static struct usb_driver irda_driver = {
	.name = "ks959-sir",
	.probe = ks959_probe,
	.disconnect = ks959_disconnect,
	.id_table = dongles,
#ifdef CONFIG_PM
	.suspend = ks959_suspend,
	.resume = ks959_resume,
#endif
};

module_usb_driver(irda_driver);

MODULE_AUTHOR("Alex Villacís Lasso <a_villacis@palosanto.com>");
MODULE_DESCRIPTION("IrDA-USB Dongle Driver for KingSun KS-959");
MODULE_LICENSE("GPL");