1/*****************************************************************************
2*
3* Filename:      stir4200.c
4* Version:       0.4
5* Description:   Irda SigmaTel USB Dongle
6* Status:        Experimental
7* Author:        Stephen Hemminger <shemminger@osdl.org>
8*
9*  	Based on earlier driver by Paul Stewart <stewart@parc.com>
10*
11*	Copyright (C) 2000, Roman Weissgaerber <weissg@vienna.at>
12*	Copyright (C) 2001, Dag Brattli <dag@brattli.net>
13*	Copyright (C) 2001, Jean Tourrilhes <jt@hpl.hp.com>
14*	Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
15*
16*	This program is free software; you can redistribute it and/or modify
17*	it under the terms of the GNU General Public License as published by
18*	the Free Software Foundation; either version 2 of the License.
19*
20*	This program is distributed in the hope that it will be useful,
21*	but WITHOUT ANY WARRANTY; without even the implied warranty of
22*	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23*	GNU General Public License for more details.
24*
25*	You should have received a copy of the GNU General Public License
26*	along with this program; if not, write to the Free Software
27*	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28*
29*****************************************************************************/
30
31/*
32 * This dongle does no framing, and requires polling to receive the
33 * data.  The STIr4200 has bulk in and out endpoints just like
34 * usr-irda devices, but the data it sends and receives is raw; like
35 * irtty, it needs to call the wrap and unwrap functions to add and
36 * remove SOF/BOF and escape characters to/from the frame.
37 */
38
39#include <linux/module.h>
40#include <linux/moduleparam.h>
41
42#include <linux/kernel.h>
43#include <linux/ktime.h>
44#include <linux/types.h>
45#include <linux/time.h>
46#include <linux/skbuff.h>
47#include <linux/netdevice.h>
48#include <linux/slab.h>
49#include <linux/delay.h>
50#include <linux/usb.h>
51#include <linux/crc32.h>
52#include <linux/kthread.h>
53#include <linux/freezer.h>
54#include <net/irda/irda.h>
55#include <net/irda/irda_device.h>
56#include <net/irda/wrapper.h>
57#include <net/irda/crc.h>
58#include <asm/byteorder.h>
59#include <asm/unaligned.h>
60
61MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
62MODULE_DESCRIPTION("IrDA-USB Dongle Driver for SigmaTel STIr4200");
63MODULE_LICENSE("GPL");
64
65static int qos_mtt_bits = 0x07;	/* 1 ms or more */
66module_param(qos_mtt_bits, int, 0);
67MODULE_PARM_DESC(qos_mtt_bits, "Minimum Turn Time");
68
69static int rx_sensitivity = 1;	/* FIR 0..4, SIR 0..6 */
70module_param(rx_sensitivity, int, 0);
71MODULE_PARM_DESC(rx_sensitivity, "Set Receiver sensitivity (0-6, 0 is most sensitive)");
72
73static int tx_power = 0;	/* 0 = highest ... 3 = lowest */
74module_param(tx_power, int, 0);
75MODULE_PARM_DESC(tx_power, "Set Transmitter power (0-3, 0 is highest power)");
76
77#define STIR_IRDA_HEADER  	4
78#define CTRL_TIMEOUT		100	   /* milliseconds */
79#define TRANSMIT_TIMEOUT	200	   /* milliseconds */
80#define STIR_FIFO_SIZE		4096
81#define FIFO_REGS_SIZE		3
82
83enum FirChars {
84	FIR_CE   = 0x7d,
85	FIR_XBOF = 0x7f,
86	FIR_EOF  = 0x7e,
87};
88
89enum StirRequests {
90	REQ_WRITE_REG =		0x00,
91	REQ_READ_REG =		0x01,
92	REQ_READ_ROM =		0x02,
93	REQ_WRITE_SINGLE =	0x03,
94};
95
96/* Register offsets */
97enum StirRegs {
98	REG_RSVD=0,
99	REG_MODE,
100	REG_PDCLK,
101	REG_CTRL1,
102	REG_CTRL2,
103	REG_FIFOCTL,
104	REG_FIFOLSB,
105	REG_FIFOMSB,
106	REG_DPLL,
107	REG_IRDIG,
108	REG_TEST=15,
109};
110
111enum StirModeMask {
112	MODE_FIR = 0x80,
113	MODE_SIR = 0x20,
114	MODE_ASK = 0x10,
115	MODE_FASTRX = 0x08,
116	MODE_FFRSTEN = 0x04,
117	MODE_NRESET = 0x02,
118	MODE_2400 = 0x01,
119};
120
121enum StirPdclkMask {
122	PDCLK_4000000 = 0x02,
123	PDCLK_115200 = 0x09,
124	PDCLK_57600 = 0x13,
125	PDCLK_38400 = 0x1D,
126	PDCLK_19200 = 0x3B,
127	PDCLK_9600 = 0x77,
128	PDCLK_2400 = 0xDF,
129};
130
131enum StirCtrl1Mask {
132	CTRL1_SDMODE = 0x80,
133	CTRL1_RXSLOW = 0x40,
134	CTRL1_TXPWD = 0x10,
135	CTRL1_RXPWD = 0x08,
136	CTRL1_SRESET = 0x01,
137};
138
139enum StirCtrl2Mask {
140	CTRL2_SPWIDTH = 0x08,
141	CTRL2_REVID = 0x03,
142};
143
144enum StirFifoCtlMask {
145	FIFOCTL_DIR = 0x10,
146	FIFOCTL_CLR = 0x08,
147	FIFOCTL_EMPTY = 0x04,
148};
149
150enum StirDiagMask {
151	IRDIG_RXHIGH = 0x80,
152	IRDIG_RXLOW = 0x40,
153};
154
155enum StirTestMask {
156	TEST_PLLDOWN = 0x80,
157	TEST_LOOPIR = 0x40,
158	TEST_LOOPUSB = 0x20,
159	TEST_TSTENA = 0x10,
160	TEST_TSTOSC = 0x0F,
161};
162
163struct stir_cb {
164        struct usb_device *usbdev;      /* init: probe_irda */
165        struct net_device *netdev;      /* network layer */
166        struct irlap_cb   *irlap;       /* The link layer we are binded to */
167
168        struct qos_info   qos;
169	unsigned 	  speed;	/* Current speed */
170
171        struct task_struct *thread;     /* transmit thread */
172
173	struct sk_buff	  *tx_pending;
174	void		  *io_buf;	/* transmit/receive buffer */
175	__u8		  *fifo_status;
176
177	iobuff_t  	  rx_buff;	/* receive unwrap state machine */
178	ktime_t		rx_time;
179	int		  receiving;
180	struct urb	 *rx_urb;
181};
182
183
184/* These are the currently known USB ids */
185static struct usb_device_id dongles[] = {
186    /* SigmaTel, Inc,  STIr4200 IrDA/USB Bridge */
187    { USB_DEVICE(0x066f, 0x4200) },
188    { }
189};
190
191MODULE_DEVICE_TABLE(usb, dongles);
192
193/* Send control message to set dongle register */
194static int write_reg(struct stir_cb *stir, __u16 reg, __u8 value)
195{
196	struct usb_device *dev = stir->usbdev;
197
198	pr_debug("%s: write reg %d = 0x%x\n",
199		 stir->netdev->name, reg, value);
200	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
201			       REQ_WRITE_SINGLE,
202			       USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_DEVICE,
203			       value, reg, NULL, 0,
204			       CTRL_TIMEOUT);
205}
206
207/* Send control message to read multiple registers */
208static inline int read_reg(struct stir_cb *stir, __u16 reg,
209		    __u8 *data, __u16 count)
210{
211	struct usb_device *dev = stir->usbdev;
212
213	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
214			       REQ_READ_REG,
215			       USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
216			       0, reg, data, count,
217			       CTRL_TIMEOUT);
218}
219
220static inline int isfir(u32 speed)
221{
222	return speed == 4000000;
223}
224
225/*
226 * Prepare a FIR IrDA frame for transmission to the USB dongle.  The
227 * FIR transmit frame is documented in the datasheet.  It consists of
228 * a two byte 0x55 0xAA sequence, two little-endian length bytes, a
229 * sequence of exactly 16 XBOF bytes of 0x7E, two BOF bytes of 0x7E,
230 * then the data escaped as follows:
231 *
232 *    0x7D -> 0x7D 0x5D
233 *    0x7E -> 0x7D 0x5E
234 *    0x7F -> 0x7D 0x5F
235 *
236 * Then, 4 bytes of little endian (stuffed) FCS follow, then two
237 * trailing EOF bytes of 0x7E.
238 */
239static inline __u8 *stuff_fir(__u8 *p, __u8 c)
240{
241	switch(c) {
242	case 0x7d:
243	case 0x7e:
244	case 0x7f:
245		*p++ = 0x7d;
246		c ^= IRDA_TRANS;
247		/* fall through */
248	default:
249		*p++ = c;
250	}
251	return p;
252}
253
254/* Take raw data in skb and put it wrapped into buf */
255static unsigned wrap_fir_skb(const struct sk_buff *skb, __u8 *buf)
256{
257	__u8 *ptr = buf;
258	__u32 fcs = ~(crc32_le(~0, skb->data, skb->len));
259	__u16 wraplen;
260	int i;
261
262	/* Header */
263	buf[0] = 0x55;
264	buf[1] = 0xAA;
265
266	ptr = buf + STIR_IRDA_HEADER;
267	memset(ptr, 0x7f, 16);
268	ptr += 16;
269
270	/* BOF */
271	*ptr++  = 0x7e;
272	*ptr++  = 0x7e;
273
274	/* Address / Control / Information */
275	for (i = 0; i < skb->len; i++)
276		ptr = stuff_fir(ptr, skb->data[i]);
277
278	/* FCS */
279	ptr = stuff_fir(ptr, fcs & 0xff);
280	ptr = stuff_fir(ptr, (fcs >> 8) & 0xff);
281	ptr = stuff_fir(ptr, (fcs >> 16) & 0xff);
282	ptr = stuff_fir(ptr, (fcs >> 24) & 0xff);
283
284	/* EOFs */
285	*ptr++ = 0x7e;
286	*ptr++ = 0x7e;
287
288	/* Total length, minus the header */
289	wraplen = (ptr - buf) - STIR_IRDA_HEADER;
290	buf[2] = wraplen & 0xff;
291	buf[3] = (wraplen >> 8) & 0xff;
292
293	return wraplen + STIR_IRDA_HEADER;
294}
295
296static unsigned wrap_sir_skb(struct sk_buff *skb, __u8 *buf)
297{
298	__u16 wraplen;
299
300	wraplen = async_wrap_skb(skb, buf + STIR_IRDA_HEADER,
301				 STIR_FIFO_SIZE - STIR_IRDA_HEADER);
302	buf[0] = 0x55;
303	buf[1] = 0xAA;
304	buf[2] = wraplen & 0xff;
305	buf[3] = (wraplen >> 8) & 0xff;
306
307	return wraplen + STIR_IRDA_HEADER;
308}
309
310/*
311 * Frame is fully formed in the rx_buff so check crc
312 * and pass up to irlap
313 * setup for next receive
314 */
315static void fir_eof(struct stir_cb *stir)
316{
317	iobuff_t *rx_buff = &stir->rx_buff;
318	int len = rx_buff->len - 4;
319	struct sk_buff *skb, *nskb;
320	__u32 fcs;
321
322	if (unlikely(len <= 0)) {
323		pr_debug("%s: short frame len %d\n",
324			 stir->netdev->name, len);
325
326		++stir->netdev->stats.rx_errors;
327		++stir->netdev->stats.rx_length_errors;
328		return;
329	}
330
331	fcs = ~(crc32_le(~0, rx_buff->data, len));
332	if (fcs != get_unaligned_le32(rx_buff->data + len)) {
333		pr_debug("crc error calc 0x%x len %d\n", fcs, len);
334		stir->netdev->stats.rx_errors++;
335		stir->netdev->stats.rx_crc_errors++;
336		return;
337	}
338
339	/* if frame is short then just copy it */
340	if (len < IRDA_RX_COPY_THRESHOLD) {
341		nskb = dev_alloc_skb(len + 1);
342		if (unlikely(!nskb)) {
343			++stir->netdev->stats.rx_dropped;
344			return;
345		}
346		skb_reserve(nskb, 1);
347		skb = nskb;
348		skb_copy_to_linear_data(nskb, rx_buff->data, len);
349	} else {
350		nskb = dev_alloc_skb(rx_buff->truesize);
351		if (unlikely(!nskb)) {
352			++stir->netdev->stats.rx_dropped;
353			return;
354		}
355		skb_reserve(nskb, 1);
356		skb = rx_buff->skb;
357		rx_buff->skb = nskb;
358		rx_buff->head = nskb->data;
359	}
360
361	skb_put(skb, len);
362
363	skb_reset_mac_header(skb);
364	skb->protocol = htons(ETH_P_IRDA);
365	skb->dev = stir->netdev;
366
367	netif_rx(skb);
368
369	stir->netdev->stats.rx_packets++;
370	stir->netdev->stats.rx_bytes += len;
371
372	rx_buff->data = rx_buff->head;
373	rx_buff->len = 0;
374}
375
376/* Unwrap FIR stuffed data and bump it to IrLAP */
377static void stir_fir_chars(struct stir_cb *stir,
378			    const __u8 *bytes, int len)
379{
380	iobuff_t *rx_buff = &stir->rx_buff;
381	int	i;
382
383	for (i = 0; i < len; i++) {
384		__u8	byte = bytes[i];
385
386		switch(rx_buff->state) {
387		case OUTSIDE_FRAME:
388			/* ignore garbage till start of frame */
389			if (unlikely(byte != FIR_EOF))
390				continue;
391			/* Now receiving frame */
392			rx_buff->state = BEGIN_FRAME;
393
394			/* Time to initialize receive buffer */
395			rx_buff->data = rx_buff->head;
396			rx_buff->len = 0;
397			continue;
398
399		case LINK_ESCAPE:
400			if (byte == FIR_EOF) {
401				pr_debug("%s: got EOF after escape\n",
402					 stir->netdev->name);
403				goto frame_error;
404			}
405			rx_buff->state = INSIDE_FRAME;
406			byte ^= IRDA_TRANS;
407			break;
408
409		case BEGIN_FRAME:
410			/* ignore multiple BOF/EOF */
411			if (byte == FIR_EOF)
412				continue;
413			rx_buff->state = INSIDE_FRAME;
414			rx_buff->in_frame = TRUE;
415
416			/* fall through */
417		case INSIDE_FRAME:
418			switch(byte) {
419			case FIR_CE:
420				rx_buff->state = LINK_ESCAPE;
421				continue;
422			case FIR_XBOF:
423				/* 0x7f is not used in this framing */
424				pr_debug("%s: got XBOF without escape\n",
425					 stir->netdev->name);
426				goto frame_error;
427			case FIR_EOF:
428				rx_buff->state = OUTSIDE_FRAME;
429				rx_buff->in_frame = FALSE;
430				fir_eof(stir);
431				continue;
432			}
433			break;
434		}
435
436		/* add byte to rx buffer */
437		if (unlikely(rx_buff->len >= rx_buff->truesize)) {
438			pr_debug("%s: fir frame exceeds %d\n",
439				 stir->netdev->name, rx_buff->truesize);
440			++stir->netdev->stats.rx_over_errors;
441			goto error_recovery;
442		}
443
444		rx_buff->data[rx_buff->len++] = byte;
445		continue;
446
447	frame_error:
448		++stir->netdev->stats.rx_frame_errors;
449
450	error_recovery:
451		++stir->netdev->stats.rx_errors;
452		rx_buff->state = OUTSIDE_FRAME;
453		rx_buff->in_frame = FALSE;
454	}
455}
456
457/* Unwrap SIR stuffed data and bump it up to IrLAP */
458static void stir_sir_chars(struct stir_cb *stir,
459			    const __u8 *bytes, int len)
460{
461	int i;
462
463	for (i = 0; i < len; i++)
464		async_unwrap_char(stir->netdev, &stir->netdev->stats,
465				  &stir->rx_buff, bytes[i]);
466}
467
468static inline void unwrap_chars(struct stir_cb *stir,
469				const __u8 *bytes, int length)
470{
471	if (isfir(stir->speed))
472		stir_fir_chars(stir, bytes, length);
473	else
474		stir_sir_chars(stir, bytes, length);
475}
476
477/* Mode parameters for each speed */
478static const struct {
479	unsigned speed;
480	__u8 pdclk;
481} stir_modes[] = {
482        { 2400,    PDCLK_2400 },
483        { 9600,    PDCLK_9600 },
484        { 19200,   PDCLK_19200 },
485        { 38400,   PDCLK_38400 },
486        { 57600,   PDCLK_57600 },
487        { 115200,  PDCLK_115200 },
488        { 4000000, PDCLK_4000000 },
489};
490
491
492/*
493 * Setup chip for speed.
494 *  Called at startup to initialize the chip
495 *  and on speed changes.
496 *
497 * Note: Write multiple registers doesn't appear to work
498 */
499static int change_speed(struct stir_cb *stir, unsigned speed)
500{
501	int i, err;
502	__u8 mode;
503
504	for (i = 0; i < ARRAY_SIZE(stir_modes); ++i) {
505		if (speed == stir_modes[i].speed)
506			goto found;
507	}
508
509	dev_warn(&stir->netdev->dev, "invalid speed %d\n", speed);
510	return -EINVAL;
511
512 found:
513	pr_debug("speed change from %d to %d\n", stir->speed, speed);
514
515	/* Reset modulator */
516	err = write_reg(stir, REG_CTRL1, CTRL1_SRESET);
517	if (err)
518		goto out;
519
520	/* Undocumented magic to tweak the DPLL */
521	err = write_reg(stir, REG_DPLL, 0x15);
522	if (err)
523		goto out;
524
525	/* Set clock */
526	err = write_reg(stir, REG_PDCLK, stir_modes[i].pdclk);
527	if (err)
528		goto out;
529
530	mode = MODE_NRESET | MODE_FASTRX;
531	if (isfir(speed))
532		mode |= MODE_FIR | MODE_FFRSTEN;
533	else
534		mode |= MODE_SIR;
535
536	if (speed == 2400)
537		mode |= MODE_2400;
538
539	err = write_reg(stir, REG_MODE, mode);
540	if (err)
541		goto out;
542
543	/* This resets TEMIC style transceiver if any. */
544	err = write_reg(stir, REG_CTRL1,
545			CTRL1_SDMODE | (tx_power & 3) << 1);
546	if (err)
547		goto out;
548
549	err = write_reg(stir, REG_CTRL1, (tx_power & 3) << 1);
550	if (err)
551		goto out;
552
553	/* Reset sensitivity */
554	err = write_reg(stir, REG_CTRL2, (rx_sensitivity & 7) << 5);
555 out:
556	stir->speed = speed;
557	return err;
558}
559
560/*
561 * Called from net/core when new frame is available.
562 */
563static netdev_tx_t stir_hard_xmit(struct sk_buff *skb,
564					struct net_device *netdev)
565{
566	struct stir_cb *stir = netdev_priv(netdev);
567
568	netif_stop_queue(netdev);
569
570	/* the IRDA wrapping routines don't deal with non linear skb */
571	SKB_LINEAR_ASSERT(skb);
572
573	skb = xchg(&stir->tx_pending, skb);
574        wake_up_process(stir->thread);
575
576	/* this should never happen unless stop/wakeup problem */
577	if (unlikely(skb)) {
578		WARN_ON(1);
579		dev_kfree_skb(skb);
580	}
581
582	return NETDEV_TX_OK;
583}
584
585/*
586 * Wait for the transmit FIFO to have space for next data
587 *
588 * If space < 0 then wait till FIFO completely drains.
589 * FYI: can take up to 13 seconds at 2400baud.
590 */
591static int fifo_txwait(struct stir_cb *stir, int space)
592{
593	int err;
594	unsigned long count, status;
595	unsigned long prev_count = 0x1fff;
596
597	/* Read FIFO status and count */
598	for (;; prev_count = count) {
599		err = read_reg(stir, REG_FIFOCTL, stir->fifo_status,
600				   FIFO_REGS_SIZE);
601		if (unlikely(err != FIFO_REGS_SIZE)) {
602			dev_warn(&stir->netdev->dev,
603				 "FIFO register read error: %d\n", err);
604
605			return err;
606		}
607
608		status = stir->fifo_status[0];
609		count = (unsigned)(stir->fifo_status[2] & 0x1f) << 8
610			| stir->fifo_status[1];
611
612		pr_debug("fifo status 0x%lx count %lu\n", status, count);
613
614		/* is fifo receiving already, or empty */
615		if (!(status & FIFOCTL_DIR) ||
616		    (status & FIFOCTL_EMPTY))
617			return 0;
618
619		if (signal_pending(current))
620			return -EINTR;
621
622		/* shutting down? */
623		if (!netif_running(stir->netdev) ||
624		    !netif_device_present(stir->netdev))
625			return -ESHUTDOWN;
626
627		/* only waiting for some space */
628		if (space >= 0 && STIR_FIFO_SIZE - 4 > space + count)
629			return 0;
630
631		/* queue confused */
632		if (prev_count < count)
633			break;
634
635		/* estimate transfer time for remaining chars */
636		msleep((count * 8000) / stir->speed);
637	}
638
639	err = write_reg(stir, REG_FIFOCTL, FIFOCTL_CLR);
640	if (err)
641		return err;
642	err = write_reg(stir, REG_FIFOCTL, 0);
643	if (err)
644		return err;
645
646	return 0;
647}
648
649
650/* Wait for turnaround delay before starting transmit.  */
651static void turnaround_delay(const struct stir_cb *stir, long us)
652{
653	long ticks;
654
655	if (us <= 0)
656		return;
657
658	us -= ktime_us_delta(ktime_get(), stir->rx_time);
659
660	if (us < 10)
661		return;
662
663	ticks = us / (1000000 / HZ);
664	if (ticks > 0)
665		schedule_timeout_interruptible(1 + ticks);
666	else
667		udelay(us);
668}
669
670/*
671 * Start receiver by submitting a request to the receive pipe.
672 * If nothing is available it will return after rx_interval.
673 */
674static int receive_start(struct stir_cb *stir)
675{
676	/* reset state */
677	stir->receiving = 1;
678
679	stir->rx_buff.in_frame = FALSE;
680	stir->rx_buff.state = OUTSIDE_FRAME;
681
682	stir->rx_urb->status = 0;
683	return usb_submit_urb(stir->rx_urb, GFP_KERNEL);
684}
685
686/* Stop all pending receive Urb's */
687static void receive_stop(struct stir_cb *stir)
688{
689	stir->receiving = 0;
690	usb_kill_urb(stir->rx_urb);
691
692	if (stir->rx_buff.in_frame)
693		stir->netdev->stats.collisions++;
694}
695/*
696 * Wrap data in socket buffer and send it.
697 */
698static void stir_send(struct stir_cb *stir, struct sk_buff *skb)
699{
700	unsigned wraplen;
701	int first_frame = 0;
702
703	/* if receiving, need to turnaround */
704	if (stir->receiving) {
705		receive_stop(stir);
706		turnaround_delay(stir, irda_get_mtt(skb));
707		first_frame = 1;
708	}
709
710	if (isfir(stir->speed))
711		wraplen = wrap_fir_skb(skb, stir->io_buf);
712	else
713		wraplen = wrap_sir_skb(skb, stir->io_buf);
714
715	/* check for space available in fifo */
716	if (!first_frame)
717		fifo_txwait(stir, wraplen);
718
719	stir->netdev->stats.tx_packets++;
720	stir->netdev->stats.tx_bytes += skb->len;
721	stir->netdev->trans_start = jiffies;
722	pr_debug("send %d (%d)\n", skb->len, wraplen);
723
724	if (usb_bulk_msg(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1),
725			 stir->io_buf, wraplen,
726			 NULL, TRANSMIT_TIMEOUT))
727		stir->netdev->stats.tx_errors++;
728}
729
730/*
731 * Transmit state machine thread
732 */
733static int stir_transmit_thread(void *arg)
734{
735	struct stir_cb *stir = arg;
736	struct net_device *dev = stir->netdev;
737	struct sk_buff *skb;
738
739        while (!kthread_should_stop()) {
740#ifdef CONFIG_PM
741		/* if suspending, then power off and wait */
742		if (unlikely(freezing(current))) {
743			if (stir->receiving)
744				receive_stop(stir);
745			else
746				fifo_txwait(stir, -1);
747
748			write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
749
750			try_to_freeze();
751
752			if (change_speed(stir, stir->speed))
753				break;
754		}
755#endif
756
757		/* if something to send? */
758		skb = xchg(&stir->tx_pending, NULL);
759		if (skb) {
760			unsigned new_speed = irda_get_next_speed(skb);
761			netif_wake_queue(dev);
762
763			if (skb->len > 0)
764				stir_send(stir, skb);
765			dev_kfree_skb(skb);
766
767			if ((new_speed != -1) && (stir->speed != new_speed)) {
768				if (fifo_txwait(stir, -1) ||
769				    change_speed(stir, new_speed))
770					break;
771			}
772			continue;
773		}
774
775		/* nothing to send? start receiving */
776		if (!stir->receiving &&
777		    irda_device_txqueue_empty(dev)) {
778			/* Wait otherwise chip gets confused. */
779			if (fifo_txwait(stir, -1))
780				break;
781
782			if (unlikely(receive_start(stir))) {
783				if (net_ratelimit())
784					dev_info(&dev->dev,
785						 "%s: receive usb submit failed\n",
786						 stir->netdev->name);
787				stir->receiving = 0;
788				msleep(10);
789				continue;
790			}
791		}
792
793		/* sleep if nothing to send */
794                set_current_state(TASK_INTERRUPTIBLE);
795                schedule();
796
797	}
798        return 0;
799}
800
801
802/*
803 * USB bulk receive completion callback.
804 * Wakes up every ms (usb round trip) with wrapped
805 * data.
806 */
807static void stir_rcv_irq(struct urb *urb)
808{
809	struct stir_cb *stir = urb->context;
810	int err;
811
812	/* in process of stopping, just drop data */
813	if (!netif_running(stir->netdev))
814		return;
815
816	/* unlink, shutdown, unplug, other nasties */
817	if (urb->status != 0)
818		return;
819
820	if (urb->actual_length > 0) {
821		pr_debug("receive %d\n", urb->actual_length);
822		unwrap_chars(stir, urb->transfer_buffer,
823			     urb->actual_length);
824
825		stir->rx_time = ktime_get();
826	}
827
828	/* kernel thread is stopping receiver don't resubmit */
829	if (!stir->receiving)
830		return;
831
832	/* resubmit existing urb */
833	err = usb_submit_urb(urb, GFP_ATOMIC);
834
835	/* in case of error, the kernel thread will restart us */
836	if (err) {
837		dev_warn(&stir->netdev->dev, "usb receive submit error: %d\n",
838			 err);
839		stir->receiving = 0;
840		wake_up_process(stir->thread);
841	}
842}
843
844/*
845 * Function stir_net_open (dev)
846 *
847 *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
848 */
849static int stir_net_open(struct net_device *netdev)
850{
851	struct stir_cb *stir = netdev_priv(netdev);
852	int err;
853	char hwname[16];
854
855	err = usb_clear_halt(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1));
856	if (err)
857		goto err_out1;
858	err = usb_clear_halt(stir->usbdev, usb_rcvbulkpipe(stir->usbdev, 2));
859	if (err)
860		goto err_out1;
861
862	err = change_speed(stir, 9600);
863	if (err)
864		goto err_out1;
865
866	err = -ENOMEM;
867
868	/* Initialize for SIR/FIR to copy data directly into skb.  */
869	stir->receiving = 0;
870	stir->rx_buff.truesize = IRDA_SKB_MAX_MTU;
871	stir->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
872	if (!stir->rx_buff.skb)
873		goto err_out1;
874
875	skb_reserve(stir->rx_buff.skb, 1);
876	stir->rx_buff.head = stir->rx_buff.skb->data;
877	stir->rx_time = ktime_get();
878
879	stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
880	if (!stir->rx_urb)
881		goto err_out2;
882
883	stir->io_buf = kmalloc(STIR_FIFO_SIZE, GFP_KERNEL);
884	if (!stir->io_buf)
885		goto err_out3;
886
887	usb_fill_bulk_urb(stir->rx_urb, stir->usbdev,
888			  usb_rcvbulkpipe(stir->usbdev, 2),
889			  stir->io_buf, STIR_FIFO_SIZE,
890			  stir_rcv_irq, stir);
891
892	stir->fifo_status = kmalloc(FIFO_REGS_SIZE, GFP_KERNEL);
893	if (!stir->fifo_status)
894		goto err_out4;
895
896	/*
897	 * Now that everything should be initialized properly,
898	 * Open new IrLAP layer instance to take care of us...
899	 * Note : will send immediately a speed change...
900	 */
901	sprintf(hwname, "usb#%d", stir->usbdev->devnum);
902	stir->irlap = irlap_open(netdev, &stir->qos, hwname);
903	if (!stir->irlap) {
904		dev_err(&stir->usbdev->dev, "irlap_open failed\n");
905		goto err_out5;
906	}
907
908	/** Start kernel thread for transmit.  */
909	stir->thread = kthread_run(stir_transmit_thread, stir,
910				   "%s", stir->netdev->name);
911        if (IS_ERR(stir->thread)) {
912                err = PTR_ERR(stir->thread);
913		dev_err(&stir->usbdev->dev, "unable to start kernel thread\n");
914		goto err_out6;
915	}
916
917	netif_start_queue(netdev);
918
919	return 0;
920
921 err_out6:
922	irlap_close(stir->irlap);
923 err_out5:
924	kfree(stir->fifo_status);
925 err_out4:
926	kfree(stir->io_buf);
927 err_out3:
928	usb_free_urb(stir->rx_urb);
929 err_out2:
930	kfree_skb(stir->rx_buff.skb);
931 err_out1:
932	return err;
933}
934
935/*
936 * Function stir_net_close (stir)
937 *
938 *    Network device is taken down. Usually this is done by
939 *    "ifconfig irda0 down"
940 */
941static int stir_net_close(struct net_device *netdev)
942{
943	struct stir_cb *stir = netdev_priv(netdev);
944
945	/* Stop transmit processing */
946	netif_stop_queue(netdev);
947
948	/* Kill transmit thread */
949	kthread_stop(stir->thread);
950	kfree(stir->fifo_status);
951
952	/* Mop up receive urb's */
953	usb_kill_urb(stir->rx_urb);
954
955	kfree(stir->io_buf);
956	usb_free_urb(stir->rx_urb);
957	kfree_skb(stir->rx_buff.skb);
958
959	/* Stop and remove instance of IrLAP */
960	if (stir->irlap)
961		irlap_close(stir->irlap);
962
963	stir->irlap = NULL;
964
965	return 0;
966}
967
968/*
969 * IOCTLs : Extra out-of-band network commands...
970 */
971static int stir_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
972{
973	struct if_irda_req *irq = (struct if_irda_req *) rq;
974	struct stir_cb *stir = netdev_priv(netdev);
975	int ret = 0;
976
977	switch (cmd) {
978	case SIOCSBANDWIDTH: /* Set bandwidth */
979		if (!capable(CAP_NET_ADMIN))
980			return -EPERM;
981
982		/* Check if the device is still there */
983		if (netif_device_present(stir->netdev))
984			ret = change_speed(stir, irq->ifr_baudrate);
985		break;
986
987	case SIOCSMEDIABUSY: /* Set media busy */
988		if (!capable(CAP_NET_ADMIN))
989			return -EPERM;
990
991		/* Check if the IrDA stack is still there */
992		if (netif_running(stir->netdev))
993			irda_device_set_media_busy(stir->netdev, TRUE);
994		break;
995
996	case SIOCGRECEIVING:
997		/* Only approximately true */
998		irq->ifr_receiving = stir->receiving;
999		break;
1000
1001	default:
1002		ret = -EOPNOTSUPP;
1003	}
1004
1005	return ret;
1006}
1007
1008static const struct net_device_ops stir_netdev_ops = {
1009	.ndo_open       = stir_net_open,
1010	.ndo_stop       = stir_net_close,
1011	.ndo_start_xmit = stir_hard_xmit,
1012	.ndo_do_ioctl   = stir_net_ioctl,
1013};
1014
1015/*
1016 * This routine is called by the USB subsystem for each new device
1017 * in the system. We need to check if the device is ours, and in
1018 * this case start handling it.
1019 * Note : it might be worth protecting this function by a global
1020 * spinlock... Or not, because maybe USB already deal with that...
1021 */
1022static int stir_probe(struct usb_interface *intf,
1023		      const struct usb_device_id *id)
1024{
1025	struct usb_device *dev = interface_to_usbdev(intf);
1026	struct stir_cb *stir = NULL;
1027	struct net_device *net;
1028	int ret = -ENOMEM;
1029
1030	/* Allocate network device container. */
1031	net = alloc_irdadev(sizeof(*stir));
1032	if(!net)
1033		goto err_out1;
1034
1035	SET_NETDEV_DEV(net, &intf->dev);
1036	stir = netdev_priv(net);
1037	stir->netdev = net;
1038	stir->usbdev = dev;
1039
1040	ret = usb_reset_configuration(dev);
1041	if (ret != 0) {
1042		dev_err(&intf->dev, "usb reset configuration failed\n");
1043		goto err_out2;
1044	}
1045
1046	printk(KERN_INFO "SigmaTel STIr4200 IRDA/USB found at address %d, "
1047		"Vendor: %x, Product: %x\n",
1048	       dev->devnum, le16_to_cpu(dev->descriptor.idVendor),
1049	       le16_to_cpu(dev->descriptor.idProduct));
1050
1051	/* Initialize QoS for this device */
1052	irda_init_max_qos_capabilies(&stir->qos);
1053
1054	/* That's the Rx capability. */
1055	stir->qos.baud_rate.bits       &= IR_2400 | IR_9600 | IR_19200 |
1056					 IR_38400 | IR_57600 | IR_115200 |
1057					 (IR_4000000 << 8);
1058	stir->qos.min_turn_time.bits   &= qos_mtt_bits;
1059	irda_qos_bits_to_value(&stir->qos);
1060
1061	/* Override the network functions we need to use */
1062	net->netdev_ops = &stir_netdev_ops;
1063
1064	ret = register_netdev(net);
1065	if (ret != 0)
1066		goto err_out2;
1067
1068	dev_info(&intf->dev, "IrDA: Registered SigmaTel device %s\n",
1069		 net->name);
1070
1071	usb_set_intfdata(intf, stir);
1072
1073	return 0;
1074
1075err_out2:
1076	free_netdev(net);
1077err_out1:
1078	return ret;
1079}
1080
1081/*
1082 * The current device is removed, the USB layer tell us to shut it down...
1083 */
1084static void stir_disconnect(struct usb_interface *intf)
1085{
1086	struct stir_cb *stir = usb_get_intfdata(intf);
1087
1088	if (!stir)
1089		return;
1090
1091	unregister_netdev(stir->netdev);
1092	free_netdev(stir->netdev);
1093
1094	usb_set_intfdata(intf, NULL);
1095}
1096
1097#ifdef CONFIG_PM
1098/* USB suspend, so power off the transmitter/receiver */
1099static int stir_suspend(struct usb_interface *intf, pm_message_t message)
1100{
1101	struct stir_cb *stir = usb_get_intfdata(intf);
1102
1103	netif_device_detach(stir->netdev);
1104	return 0;
1105}
1106
1107/* Coming out of suspend, so reset hardware */
1108static int stir_resume(struct usb_interface *intf)
1109{
1110	struct stir_cb *stir = usb_get_intfdata(intf);
1111
1112	netif_device_attach(stir->netdev);
1113
1114	/* receiver restarted when send thread wakes up */
1115	return 0;
1116}
1117#endif
1118
1119/*
1120 * USB device callbacks
1121 */
1122static struct usb_driver irda_driver = {
1123	.name		= "stir4200",
1124	.probe		= stir_probe,
1125	.disconnect	= stir_disconnect,
1126	.id_table	= dongles,
1127#ifdef CONFIG_PM
1128	.suspend	= stir_suspend,
1129	.resume		= stir_resume,
1130#endif
1131};
1132
1133module_usb_driver(irda_driver);
1134