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, or
 19 *       (at your option) any later version.
 20 *
 21 *       This program is distributed in the hope that it will be useful,
 22 *       but WITHOUT ANY WARRANTY; without even the implied warranty of
 23 *       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 24 *       GNU General Public License for more details.
 25 *
 26 *       You should have received a copy of the GNU General Public License
 27 *       along with this program; if not, write to the Free Software
 28 *       Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 29 *
 30 *****************************************************************************/
 31 
 32 /*
 33  * This dongle does no framing, and requires polling to receive the
 34  * data.  The STIr4200 has bulk in and out endpoints just like
 35  * usr-irda devices, but the data it sends and receives is raw; like
 36  * irtty, it needs to call the wrap and unwrap functions to add and
 37  * remove SOF/BOF and escape characters to/from the frame.
 38  */
 39 
 40 #include <linux/module.h>
 41 #include <linux/moduleparam.h>
 42 
 43 #include <linux/kernel.h>
 44 #include <linux/types.h>
 45 #include <linux/init.h>
 46 #include <linux/time.h>
 47 #include <linux/skbuff.h>
 48 #include <linux/netdevice.h>
 49 #include <linux/suspend.h>
 50 #include <linux/slab.h>
 51 #include <linux/usb.h>
 52 #include <linux/crc32.h>
 53 #include <net/irda/irda.h>
 54 #include <net/irda/irlap.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 
 61 MODULE_AUTHOR("Stephen Hemminger <shemminger@osdl.org>");
 62 MODULE_DESCRIPTION("IrDA-USB Dongle Driver for SigmaTel STIr4200");
 63 MODULE_LICENSE("GPL");
 64 
 65 static int qos_mtt_bits = 0x07; /* 1 ms or more */
 66 module_param(qos_mtt_bits, int, 0);
 67 MODULE_PARM_DESC(qos_mtt_bits, "Minimum Turn Time");
 68 
 69 static int rx_sensitivity = 1;  /* FIR 0..4, SIR 0..6 */
 70 module_param(rx_sensitivity, int, 0);
 71 MODULE_PARM_DESC(rx_sensitivity, "Set Receiver sensitivity (0-6, 0 is most sensitive)");
 72 
 73 static int tx_power = 0;        /* 0 = highest ... 3 = lowest */
 74 module_param(tx_power, int, 0);
 75 MODULE_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 
 83 enum FirChars {
 84         FIR_CE   = 0x7d,
 85         FIR_XBOF = 0x7f,
 86         FIR_EOF  = 0x7e,
 87 };
 88 
 89 enum 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 */
 97 enum 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 
111 enum 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 
121 enum 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 
131 enum StirCtrl1Mask {
132         CTRL1_SDMODE = 0x80,
133         CTRL1_RXSLOW = 0x40,
134         CTRL1_TXPWD = 0x10,
135         CTRL1_RXPWD = 0x08,
136         CTRL1_SRESET = 0x01,
137 };
138 
139 enum StirCtrl2Mask {
140         CTRL2_SPWIDTH = 0x08,
141         CTRL2_REVID = 0x03,
142 };
143 
144 enum StirFifoCtlMask {
145         FIFOCTL_EOF = 0x80,
146         FIFOCTL_UNDER = 0x40,
147         FIFOCTL_OVER = 0x20,
148         FIFOCTL_DIR = 0x10,
149         FIFOCTL_CLR = 0x08,
150         FIFOCTL_EMPTY = 0x04,
151         FIFOCTL_RXERR = 0x02,
152         FIFOCTL_TXERR = 0x01,
153 };
154 
155 enum StirDiagMask {
156         IRDIG_RXHIGH = 0x80,
157         IRDIG_RXLOW = 0x40,
158 };
159 
160 enum StirTestMask {
161         TEST_PLLDOWN = 0x80,
162         TEST_LOOPIR = 0x40,
163         TEST_LOOPUSB = 0x20,
164         TEST_TSTENA = 0x10,
165         TEST_TSTOSC = 0x0F,
166 };
167 
168 struct stir_cb {
169         struct usb_device *usbdev;      /* init: probe_irda */
170         struct net_device *netdev;      /* network layer */
171         struct irlap_cb   *irlap;       /* The link layer we are binded to */
172         struct net_device_stats stats;  /* network statistics */
173         struct qos_info   qos;
174         unsigned          speed;        /* Current speed */
175 
176         wait_queue_head_t thr_wait;     /* transmit thread wakeup */
177         struct completion thr_exited;
178         pid_t             thr_pid;
179 
180         struct sk_buff    *tx_pending;
181         void              *io_buf;      /* transmit/receive buffer */
182         __u8              *fifo_status;
183 
184         iobuff_t          rx_buff;      /* receive unwrap state machine */
185         struct timeval    rx_time;
186         int               receiving;
187         struct urb       *rx_urb;
188 };
189 
190 
191 /* These are the currently known USB ids */
192 static struct usb_device_id dongles[] = {
193     /* SigmaTel, Inc,  STIr4200 IrDA/USB Bridge */
194     { USB_DEVICE(0x066f, 0x4200) },
195     { }
196 };
197 
198 MODULE_DEVICE_TABLE(usb, dongles);
199 
200 /* Send control message to set dongle register */
201 static int write_reg(struct stir_cb *stir, __u16 reg, __u8 value)
202 {
203         struct usb_device *dev = stir->usbdev;
204 
205         pr_debug("%s: write reg %d = 0x%x\n",
206                  stir->netdev->name, reg, value);
207         return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
208                                REQ_WRITE_SINGLE,
209                                USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_DEVICE,
210                                value, reg, NULL, 0,
211                                MSECS_TO_JIFFIES(CTRL_TIMEOUT));
212 }
213 
214 /* Send control message to read multiple registers */
215 static inline int read_reg(struct stir_cb *stir, __u16 reg,
216                     __u8 *data, __u16 count)
217 {
218         struct usb_device *dev = stir->usbdev;
219 
220         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
221                                REQ_READ_REG,
222                                USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
223                                0, reg, data, count,
224                                MSECS_TO_JIFFIES(CTRL_TIMEOUT));
225 }
226 
227 static inline int isfir(u32 speed)
228 {
229         return (speed == 4000000);
230 }
231 
232 /*
233  * Prepare a FIR IrDA frame for transmission to the USB dongle.  The
234  * FIR transmit frame is documented in the datasheet.  It consists of
235  * a two byte 0x55 0xAA sequence, two little-endian length bytes, a
236  * sequence of exactly 16 XBOF bytes of 0x7E, two BOF bytes of 0x7E,
237  * then the data escaped as follows:
238  *
239  *    0x7D -> 0x7D 0x5D
240  *    0x7E -> 0x7D 0x5E
241  *    0x7F -> 0x7D 0x5F
242  *
243  * Then, 4 bytes of little endian (stuffed) FCS follow, then two
244  * trailing EOF bytes of 0x7E.
245  */
246 static inline __u8 *stuff_fir(__u8 *p, __u8 c)
247 {
248         switch(c) {
249         case 0x7d:
250         case 0x7e:
251         case 0x7f:
252                 *p++ = 0x7d;
253                 c ^= IRDA_TRANS;
254                 /* fall through */
255         default:
256                 *p++ = c;
257         }
258         return p;
259 }
260 
261 /* Take raw data in skb and put it wrapped into buf */
262 static unsigned wrap_fir_skb(const struct sk_buff *skb, __u8 *buf)
263 {
264         __u8 *ptr = buf;
265         __u32 fcs = ~(crc32_le(~0, skb->data, skb->len));
266         __u16 wraplen;
267         int i;
268 
269         /* Header */
270         buf[0] = 0x55;
271         buf[1] = 0xAA;
272 
273         ptr = buf + STIR_IRDA_HEADER;
274         memset(ptr, 0x7f, 16);
275         ptr += 16;
276 
277         /* BOF */
278         *ptr++  = 0x7e;
279         *ptr++  = 0x7e;
280 
281         /* Address / Control / Information */
282         for (i = 0; i < skb->len; i++)
283                 ptr = stuff_fir(ptr, skb->data[i]);
284 
285         /* FCS */
286         ptr = stuff_fir(ptr, fcs & 0xff);
287         ptr = stuff_fir(ptr, (fcs >> 8) & 0xff);
288         ptr = stuff_fir(ptr, (fcs >> 16) & 0xff);
289         ptr = stuff_fir(ptr, (fcs >> 24) & 0xff);
290 
291         /* EOFs */
292         *ptr++ = 0x7e;
293         *ptr++ = 0x7e;
294 
295         /* Total length, minus the header */
296         wraplen = (ptr - buf) - STIR_IRDA_HEADER;
297         buf[2] = wraplen & 0xff;
298         buf[3] = (wraplen >> 8) & 0xff;
299 
300         return wraplen + STIR_IRDA_HEADER;
301 }
302 
303 static unsigned wrap_sir_skb(struct sk_buff *skb, __u8 *buf)
304 {
305         __u16 wraplen;
306 
307         wraplen = async_wrap_skb(skb, buf + STIR_IRDA_HEADER,
308                                  STIR_FIFO_SIZE - STIR_IRDA_HEADER);
309         buf[0] = 0x55;
310         buf[1] = 0xAA;
311         buf[2] = wraplen & 0xff;
312         buf[3] = (wraplen >> 8) & 0xff;
313 
314         return wraplen + STIR_IRDA_HEADER;
315 }
316 
317 /*
318  * Frame is fully formed in the rx_buff so check crc
319  * and pass up to irlap
320  * setup for next receive
321  */
322 static void fir_eof(struct stir_cb *stir)
323 {
324         iobuff_t *rx_buff = &stir->rx_buff;
325         int len = rx_buff->len - 4;
326         struct sk_buff *skb, *nskb;
327         __u32 fcs;
328 
329         if (unlikely(len <= 0)) {
330                 pr_debug("%s: short frame len %d\n",
331                          stir->netdev->name, len);
332 
333                 ++stir->stats.rx_errors;
334                 ++stir->stats.rx_length_errors;
335                 return;
336         }
337 
338         fcs = ~(crc32_le(~0, rx_buff->data, len));
339         if (fcs != le32_to_cpu(get_unaligned((u32 *)(rx_buff->data+len)))) {
340                 pr_debug("crc error calc 0x%x len %d\n", fcs, len);
341                 stir->stats.rx_errors++;
342                 stir->stats.rx_crc_errors++;
343                 return;
344         }
345 
346         /* if frame is short then just copy it */
347         if (len < IRDA_RX_COPY_THRESHOLD) {
348                 nskb = dev_alloc_skb(len + 1);
349                 if (unlikely(!nskb)) {
350                         ++stir->stats.rx_dropped;
351                         return;
352                 }
353                 skb_reserve(nskb, 1);
354                 skb = nskb;
355                 memcpy(nskb->data, rx_buff->data, len);
356         } else {
357                 nskb = dev_alloc_skb(rx_buff->truesize);
358                 if (unlikely(!nskb)) {
359                         ++stir->stats.rx_dropped;
360                         return;
361                 }
362                 skb_reserve(nskb, 1);
363                 skb = rx_buff->skb;
364                 rx_buff->skb = nskb;
365                 rx_buff->head = nskb->data;
366         }
367 
368         skb_put(skb, len);
369 
370         skb->mac.raw  = skb->data;
371         skb->protocol = htons(ETH_P_IRDA);
372         skb->dev = stir->netdev;
373 
374         netif_rx(skb);
375 
376         stir->stats.rx_packets++;
377         stir->stats.rx_bytes += len;
378 
379         rx_buff->data = rx_buff->head;
380         rx_buff->len = 0;
381 }
382 
383 /* Unwrap FIR stuffed data and bump it to IrLAP */
384 static void stir_fir_chars(struct stir_cb *stir,
385                             const __u8 *bytes, int len)
386 {
387         iobuff_t *rx_buff = &stir->rx_buff;
388         int     i;
389 
390         for (i = 0; i < len; i++) {
391                 __u8    byte = bytes[i];
392 
393                 switch(rx_buff->state) {
394                 case OUTSIDE_FRAME:
395                         /* ignore garbage till start of frame */
396                         if (unlikely(byte != FIR_EOF))
397                                 continue;
398                         /* Now receiving frame */
399                         rx_buff->state = BEGIN_FRAME;
400 
401                         /* Time to initialize receive buffer */
402                         rx_buff->data = rx_buff->head;
403                         rx_buff->len = 0;
404                         continue;
405 
406                 case LINK_ESCAPE:
407                         if (byte == FIR_EOF) {
408                                 pr_debug("%s: got EOF after escape\n",
409                                          stir->netdev->name);
410                                 goto frame_error;
411                         }
412                         rx_buff->state = INSIDE_FRAME;
413                         byte ^= IRDA_TRANS;
414                         break;
415 
416                 case BEGIN_FRAME:
417                         /* ignore multiple BOF/EOF */
418                         if (byte == FIR_EOF)
419                                 continue;
420                         rx_buff->state = INSIDE_FRAME;
421                         rx_buff->in_frame = TRUE;
422 
423                         /* fall through */
424                 case INSIDE_FRAME:
425                         switch(byte) {
426                         case FIR_CE:
427                                 rx_buff->state = LINK_ESCAPE;
428                                 continue;
429                         case FIR_XBOF:
430                                 /* 0x7f is not used in this framing */
431                                 pr_debug("%s: got XBOF without escape\n",
432                                          stir->netdev->name);
433                                 goto frame_error;
434                         case FIR_EOF:
435                                 rx_buff->state = OUTSIDE_FRAME;
436                                 rx_buff->in_frame = FALSE;
437                                 fir_eof(stir);
438                                 continue;
439                         }
440                         break;
441                 }
442 
443                 /* add byte to rx buffer */
444                 if (unlikely(rx_buff->len >= rx_buff->truesize)) {
445                         pr_debug("%s: fir frame exceeds %d\n",
446                                  stir->netdev->name, rx_buff->truesize);
447                         ++stir->stats.rx_over_errors;
448                         goto error_recovery;
449                 }
450 
451                 rx_buff->data[rx_buff->len++] = byte;
452                 continue;
453 
454         frame_error:
455                 ++stir->stats.rx_frame_errors;
456 
457         error_recovery:
458                 ++stir->stats.rx_errors;
459                 rx_buff->state = OUTSIDE_FRAME;
460                 rx_buff->in_frame = FALSE;
461         }
462 }
463 
464 /* Unwrap SIR stuffed data and bump it up to IrLAP */
465 static void stir_sir_chars(struct stir_cb *stir,
466                             const __u8 *bytes, int len)
467 {
468         int i;
469 
470         for (i = 0; i < len; i++)
471                 async_unwrap_char(stir->netdev, &stir->stats,
472                                   &stir->rx_buff, bytes[i]);
473 }
474 
475 static inline void unwrap_chars(struct stir_cb *stir,
476                                 const __u8 *bytes, int length)
477 {
478         if (isfir(stir->speed))
479                 stir_fir_chars(stir, bytes, length);
480         else
481                 stir_sir_chars(stir, bytes, length);
482 }
483 
484 /* Mode parameters for each speed */
485 static const struct {
486         unsigned speed;
487         __u8 pdclk;
488 } stir_modes[] = {
489         { 2400,    PDCLK_2400 },
490         { 9600,    PDCLK_9600 },
491         { 19200,   PDCLK_19200 },
492         { 38400,   PDCLK_38400 },
493         { 57600,   PDCLK_57600 },
494         { 115200,  PDCLK_115200 },
495         { 4000000, PDCLK_4000000 },
496 };
497 
498 
499 /*
500  * Setup chip for speed.
501  *  Called at startup to initialize the chip
502  *  and on speed changes.
503  *
504  * Note: Write multiple registers doesn't appear to work
505  */
506 static int change_speed(struct stir_cb *stir, unsigned speed)
507 {
508         int i, err;
509         __u8 mode;
510 
511         for (i = 0; i < ARRAY_SIZE(stir_modes); ++i) {
512                 if (speed == stir_modes[i].speed)
513                         goto found;
514         }
515 
516         warn("%s: invalid speed %d", stir->netdev->name, speed);
517         return -EINVAL;
518 
519  found:
520         pr_debug("speed change from %d to %d\n", stir->speed, speed);
521 
522         /* sometimes needed to get chip out of stuck state */
523         err = usb_reset_device(stir->usbdev);
524         if (err)
525                 goto out;
526 
527         /* Reset modulator */
528         err = write_reg(stir, REG_CTRL1, CTRL1_SRESET);
529         if (err)
530                 goto out;
531 
532         /* Undocumented magic to tweak the DPLL */
533         err = write_reg(stir, REG_DPLL, 0x15);
534         if (err)
535                 goto out;
536 
537         /* Set clock */
538         err = write_reg(stir, REG_PDCLK, stir_modes[i].pdclk);
539         if (err)
540                 goto out;
541 
542         mode = MODE_NRESET | MODE_FASTRX;
543         if (isfir(speed))
544                 mode |= MODE_FIR | MODE_FFRSTEN;
545         else
546                 mode |= MODE_SIR;
547 
548         if (speed == 2400)
549                 mode |= MODE_2400;
550 
551         err = write_reg(stir, REG_MODE, mode);
552         if (err)
553                 goto out;
554 
555         /* This resets TEMIC style transceiver if any. */
556         err = write_reg(stir, REG_CTRL1,
557                         CTRL1_SDMODE | (tx_power & 3) << 1);
558         if (err)
559                 goto out;
560 
561         err = write_reg(stir, REG_CTRL1, (tx_power & 3) << 1);
562         if (err)
563                 goto out;
564 
565         /* Reset sensitivity */
566         err = write_reg(stir, REG_CTRL2, (rx_sensitivity & 7) << 5);
567  out:
568         stir->speed = speed;
569         return err;
570 }
571 
572 /*
573  * Called from net/core when new frame is available.
574  */
575 static int stir_hard_xmit(struct sk_buff *skb, struct net_device *netdev)
576 {
577         struct stir_cb *stir = netdev->priv;
578 
579         netif_stop_queue(netdev);
580 
581         /* the IRDA wrapping routines don't deal with non linear skb */
582         SKB_LINEAR_ASSERT(skb);
583 
584         skb = xchg(&stir->tx_pending, skb);
585         wake_up(&stir->thr_wait);
586         
587         /* this should never happen unless stop/wakeup problem */
588         if (unlikely(skb)) {
589                 WARN_ON(1);
590                 dev_kfree_skb(skb);
591         }
592 
593         return 0;
594 }
595 
596 /*
597  * Wait for the transmit FIFO to have space for next data
598  *
599  * If space < 0 then wait till FIFO completely drains.
600  * FYI: can take up to 13 seconds at 2400baud.
601  */
602 static int fifo_txwait(struct stir_cb *stir, int space)
603 {
604         int err;
605         unsigned long count, status;
606 
607         /* Read FIFO status and count */
608         for(;;) {
609                 err = read_reg(stir, REG_FIFOCTL, stir->fifo_status, 
610                                    FIFO_REGS_SIZE);
611                 if (unlikely(err != FIFO_REGS_SIZE)) {
612                         warn("%s: FIFO register read error: %d", 
613                              stir->netdev->name, err);
614 
615                         return err;
616                 }
617 
618                 status = stir->fifo_status[0];
619                 count = (unsigned)(stir->fifo_status[2] & 0x1f) << 8 
620                         | stir->fifo_status[1];
621 
622                 pr_debug("fifo status 0x%lx count %lu\n", status, count);
623 
624                 /* error when receive/transmit fifo gets confused */
625                 if (status & FIFOCTL_RXERR) {
626                         stir->stats.rx_fifo_errors++;
627                         stir->stats.rx_errors++;
628                         break;
629                 }
630 
631                 if (status & FIFOCTL_TXERR) {
632                         stir->stats.tx_fifo_errors++;
633                         stir->stats.tx_errors++;
634                         break;
635                 }
636 
637                 /* is fifo receiving already, or empty */
638                 if (!(status & FIFOCTL_DIR)
639                     || (status & FIFOCTL_EMPTY))
640                         return 0;
641 
642                 if (signal_pending(current))
643                         return -EINTR;
644 
645                 /* shutting down? */
646                 if (!netif_running(stir->netdev)
647                     || !netif_device_present(stir->netdev))
648                         return -ESHUTDOWN;
649 
650                 /* only waiting for some space */
651                 if (space >= 0 && STIR_FIFO_SIZE - 4 > space + count)
652                         return 0;
653 
654                 /* estimate transfer time for remaining chars */
655                 wait_ms((count * 8000) / stir->speed);
656         }
657                         
658         err = write_reg(stir, REG_FIFOCTL, FIFOCTL_CLR);
659         if (err) 
660                 return err;
661         err = write_reg(stir, REG_FIFOCTL, 0);
662         if (err)
663                 return err;
664 
665         return 0;
666 }
667 
668 
669 /* Wait for turnaround delay before starting transmit.  */
670 static void turnaround_delay(const struct stir_cb *stir, long us)
671 {
672         long ticks;
673         struct timeval now;
674 
675         if (us <= 0)
676                 return;
677 
678         do_gettimeofday(&now);
679         us -= (now.tv_sec - stir->rx_time.tv_sec) * USEC_PER_SEC;
680         us -= now.tv_usec - stir->rx_time.tv_usec;
681         if (us < 10)
682                 return;
683 
684         ticks = us / (1000000 / HZ);
685         if (ticks > 0) {
686                 current->state = TASK_INTERRUPTIBLE;
687                 schedule_timeout(1 + ticks);
688         } else
689                 udelay(us);
690 }
691 
692 /*
693  * Start receiver by submitting a request to the receive pipe.
694  * If nothing is available it will return after rx_interval.
695  */
696 static int receive_start(struct stir_cb *stir)
697 {
698         /* reset state */
699         stir->receiving = 1;
700 
701         stir->rx_buff.in_frame = FALSE;
702         stir->rx_buff.state = OUTSIDE_FRAME;
703 
704         stir->rx_urb->status = 0;
705         return usb_submit_urb(stir->rx_urb, GFP_KERNEL);
706 }
707 
708 /* Stop all pending receive Urb's */
709 static void receive_stop(struct stir_cb *stir)
710 {
711         stir->receiving = 0;
712         usb_unlink_urb(stir->rx_urb);
713 
714         if (stir->rx_buff.in_frame) 
715                 stir->stats.collisions++;
716 }
717 /*
718  * Wrap data in socket buffer and send it.
719  */
720 static void stir_send(struct stir_cb *stir, struct sk_buff *skb)
721 {
722         unsigned wraplen;
723         int first_frame = 0;
724 
725         /* if receiving, need to turnaround */
726         if (stir->receiving) {
727                 receive_stop(stir);
728                 turnaround_delay(stir, irda_get_mtt(skb));
729                 first_frame = 1;
730         }
731 
732         if (isfir(stir->speed))
733                 wraplen = wrap_fir_skb(skb, stir->io_buf);
734         else
735                 wraplen = wrap_sir_skb(skb, stir->io_buf);
736                 
737         /* check for space available in fifo */
738         if (!first_frame)
739                 fifo_txwait(stir, wraplen);
740 
741         stir->stats.tx_packets++;
742         stir->stats.tx_bytes += skb->len;
743         stir->netdev->trans_start = jiffies;
744         pr_debug("send %d (%d)\n", skb->len, wraplen);
745 
746         if (usb_bulk_msg(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1),
747                          stir->io_buf, wraplen,
748                          NULL, MSECS_TO_JIFFIES(TRANSMIT_TIMEOUT))) 
749                 stir->stats.tx_errors++;
750 }
751 
752 /*
753  * Transmit state machine thread
754  */
755 static int stir_transmit_thread(void *arg)
756 {
757         struct stir_cb *stir = arg;
758         struct net_device *dev = stir->netdev;
759         struct sk_buff *skb;
760 
761         daemonize("%s", dev->name);
762         allow_signal(SIGTERM);
763 
764         while (netif_running(dev)
765                && netif_device_present(dev)
766                && !signal_pending(current))
767         {
768                 /* if suspending, then power off and wait */
769                 if (current->flags & PF_FREEZE) {
770                         if (stir->receiving)
771                                 receive_stop(stir);
772                         else
773                                 fifo_txwait(stir, -1);
774 
775                         write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
776 
777                         refrigerator(PF_IOTHREAD);
778 
779                         if (change_speed(stir, stir->speed))
780                                 break;
781                 }
782 
783                 /* if something to send? */
784                 skb = xchg(&stir->tx_pending, NULL);
785                 if (skb) {
786                         unsigned new_speed = irda_get_next_speed(skb);
787                         netif_wake_queue(dev);
788 
789                         if (skb->len > 0)
790                                 stir_send(stir, skb);
791                         dev_kfree_skb(skb);
792 
793                         if (stir->speed != new_speed) {
794                                 if (fifo_txwait(stir, -1) ||
795                                     change_speed(stir, new_speed))
796                                         break;
797                         }
798                         continue;
799                 }
800 
801                 /* nothing to send? start receiving */
802                 if (!stir->receiving 
803                     && irda_device_txqueue_empty(dev)) {
804                         /* Wait otherwise chip gets confused. */
805                         if (fifo_txwait(stir, -1))
806                                 break;
807 
808                         if (unlikely(receive_start(stir))) {
809                                 if (net_ratelimit())
810                                         info("%s: receive usb submit failed",
811                                              stir->netdev->name);
812                                 stir->receiving = 0;
813                                 wait_ms(10);
814                                 continue;
815                         }
816                 }
817 
818                 /* sleep if nothing to send */
819                 wait_event_interruptible(stir->thr_wait, stir->tx_pending);
820         }
821 
822         complete_and_exit (&stir->thr_exited, 0);
823 }
824 
825 
826 /*
827  * USB bulk receive completion callback.
828  * Wakes up every ms (usb round trip) with wrapped 
829  * data.
830  */
831 static void stir_rcv_irq(struct urb *urb, struct pt_regs *regs)
832 {
833         struct stir_cb *stir = urb->context;
834         int err;
835 
836         /* in process of stopping, just drop data */
837         if (!netif_running(stir->netdev))
838                 return;
839 
840         /* unlink, shutdown, unplug, other nasties */
841         if (urb->status != 0) 
842                 return;
843 
844         if (urb->actual_length > 0) {
845                 pr_debug("receive %d\n", urb->actual_length);
846                 unwrap_chars(stir, urb->transfer_buffer,
847                              urb->actual_length);
848                 
849                 stir->netdev->last_rx = jiffies;
850                 do_gettimeofday(&stir->rx_time);
851         }
852 
853         /* kernel thread is stopping receiver don't resubmit */
854         if (!stir->receiving)
855                 return;
856 
857         /* resubmit existing urb */
858         err = usb_submit_urb(urb, GFP_ATOMIC);
859 
860         /* in case of error, the kernel thread will restart us */
861         if (err) {
862                 warn("%s: usb receive submit error: %d",
863                         stir->netdev->name, err);
864                 stir->receiving = 0;
865                 wake_up(&stir->thr_wait);
866         }
867 }
868 
869 /*
870  * Function stir_net_open (dev)
871  *
872  *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
873  */
874 static int stir_net_open(struct net_device *netdev)
875 {
876         struct stir_cb *stir = netdev->priv;
877         int err;
878         char hwname[16];
879 
880         err = usb_clear_halt(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1));
881         if (err)
882                 goto err_out1;
883         err = usb_clear_halt(stir->usbdev, usb_rcvbulkpipe(stir->usbdev, 2));
884         if (err)
885                 goto err_out1;
886 
887         err = change_speed(stir, 9600);
888         if (err)
889                 goto err_out1;
890 
891         err = -ENOMEM;
892 
893         /* Initialize for SIR/FIR to copy data directly into skb.  */
894         stir->receiving = 0;
895         stir->rx_buff.truesize = IRDA_SKB_MAX_MTU;
896         stir->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
897         if (!stir->rx_buff.skb) 
898                 goto err_out1;
899 
900         skb_reserve(stir->rx_buff.skb, 1);
901         stir->rx_buff.head = stir->rx_buff.skb->data;
902         do_gettimeofday(&stir->rx_time);
903 
904         stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
905         if (!stir->rx_urb) 
906                 goto err_out2;
907 
908         stir->io_buf = kmalloc(STIR_FIFO_SIZE, GFP_KERNEL);
909         if (!stir->io_buf)
910                 goto err_out3;
911 
912         usb_fill_bulk_urb(stir->rx_urb, stir->usbdev,
913                           usb_rcvbulkpipe(stir->usbdev, 2),
914                           stir->io_buf, STIR_FIFO_SIZE,
915                           stir_rcv_irq, stir);
916 
917         stir->fifo_status = kmalloc(FIFO_REGS_SIZE, GFP_KERNEL);
918         if (!stir->fifo_status) 
919                 goto err_out4;
920                 
921         /*
922          * Now that everything should be initialized properly,
923          * Open new IrLAP layer instance to take care of us...
924          * Note : will send immediately a speed change...
925          */
926         sprintf(hwname, "usb#%d", stir->usbdev->devnum);
927         stir->irlap = irlap_open(netdev, &stir->qos, hwname);
928         if (!stir->irlap) {
929                 err("irlap_open failed");
930                 goto err_out5;
931         }
932 
933         /** Start kernel thread for transmit.  */
934         stir->thr_pid = kernel_thread(stir_transmit_thread, stir,
935                                       CLONE_FS|CLONE_FILES);
936         if (stir->thr_pid < 0) {
937                 err = stir->thr_pid;
938                 err("unable to start kernel thread");
939                 goto err_out6;
940         }
941 
942         netif_start_queue(netdev);
943 
944         return 0;
945 
946  err_out6:
947         irlap_close(stir->irlap);
948  err_out5:
949         kfree(stir->fifo_status);
950  err_out4:
951         kfree(stir->io_buf);
952  err_out3:
953         usb_free_urb(stir->rx_urb);
954  err_out2:
955         kfree_skb(stir->rx_buff.skb);
956  err_out1:
957         return err;
958 }
959 
960 /*
961  * Function stir_net_close (stir)
962  *
963  *    Network device is taken down. Usually this is done by
964  *    "ifconfig irda0 down"
965  */
966 static int stir_net_close(struct net_device *netdev)
967 {
968         struct stir_cb *stir = netdev->priv;
969 
970         /* Stop transmit processing */
971         netif_stop_queue(netdev);
972 
973         /* Kill transmit thread */
974         kill_proc(stir->thr_pid, SIGTERM, 1);
975         wait_for_completion(&stir->thr_exited);
976         kfree(stir->fifo_status);
977 
978         /* Mop up receive urb's */
979         usb_unlink_urb(stir->rx_urb);
980         
981         kfree(stir->io_buf);
982         usb_free_urb(stir->rx_urb);
983         kfree_skb(stir->rx_buff.skb);
984 
985         /* Stop and remove instance of IrLAP */
986         if (stir->irlap)
987                 irlap_close(stir->irlap);
988 
989         stir->irlap = NULL;
990 
991         return 0;
992 }
993 
994 /*
995  * IOCTLs : Extra out-of-band network commands...
996  */
997 static int stir_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
998 {
999         struct if_irda_req *irq = (struct if_irda_req *) rq;
1000         struct stir_cb *stir = dev->priv;
1001         int ret = 0;
1002 
1003         switch (cmd) {
1004         case SIOCSBANDWIDTH: /* Set bandwidth */
1005                 if (!capable(CAP_NET_ADMIN))
1006                         return -EPERM;
1007 
1008                 /* Check if the device is still there */
1009                 if (netif_device_present(stir->netdev))
1010                         ret = change_speed(stir, irq->ifr_baudrate);
1011                 break;
1012 
1013         case SIOCSMEDIABUSY: /* Set media busy */
1014                 if (!capable(CAP_NET_ADMIN))
1015                         return -EPERM;
1016 
1017                 /* Check if the IrDA stack is still there */
1018                 if (netif_running(stir->netdev))
1019                         irda_device_set_media_busy(stir->netdev, TRUE);
1020                 break;
1021 
1022         case SIOCGRECEIVING:
1023                 /* Only approximately true */
1024                 irq->ifr_receiving = stir->receiving;
1025                 break;
1026 
1027         default:
1028                 ret = -EOPNOTSUPP;
1029         }
1030 
1031         return ret;
1032 }
1033 
1034 /*
1035  * Get device stats (for /proc/net/dev and ifconfig)
1036  */
1037 static struct net_device_stats *stir_net_get_stats(struct net_device *dev)
1038 {
1039         struct stir_cb *stir = dev->priv;
1040         return &stir->stats;
1041 }
1042 
1043 /*
1044  * This routine is called by the USB subsystem for each new device
1045  * in the system. We need to check if the device is ours, and in
1046  * this case start handling it.
1047  * Note : it might be worth protecting this function by a global
1048  * spinlock... Or not, because maybe USB already deal with that...
1049  */
1050 static int stir_probe(struct usb_interface *intf,
1051                       const struct usb_device_id *id)
1052 {
1053         struct usb_device *dev = interface_to_usbdev(intf);
1054         struct stir_cb *stir = NULL;
1055         struct net_device *net;
1056         int ret = -ENOMEM;
1057 
1058         /* Allocate network device container. */
1059         net = alloc_irdadev(sizeof(*stir));
1060         if(!net)
1061                 goto err_out1;
1062 
1063         SET_MODULE_OWNER(net);
1064         SET_NETDEV_DEV(net, &intf->dev);
1065         stir = net->priv;
1066         stir->netdev = net;
1067         stir->usbdev = dev;
1068 
1069         ret = usb_reset_configuration(dev);
1070         if (ret != 0) {
1071                 err("usb reset configuration failed");
1072                 goto err_out2;
1073         }
1074 
1075         printk(KERN_INFO "SigmaTel STIr4200 IRDA/USB found at address %d, "
1076                 "Vendor: %x, Product: %x\n",
1077                dev->devnum, dev->descriptor.idVendor,
1078                dev->descriptor.idProduct);
1079 
1080         /* Initialize QoS for this device */
1081         irda_init_max_qos_capabilies(&stir->qos);
1082 
1083         /* That's the Rx capability. */
1084         stir->qos.baud_rate.bits       &= IR_2400 | IR_9600 | IR_19200 |
1085                                          IR_38400 | IR_57600 | IR_115200 |
1086                                          (IR_4000000 << 8);
1087         stir->qos.min_turn_time.bits   &= qos_mtt_bits;
1088         irda_qos_bits_to_value(&stir->qos);
1089 
1090         init_completion (&stir->thr_exited);
1091         init_waitqueue_head (&stir->thr_wait);
1092 
1093         /* Override the network functions we need to use */
1094         net->hard_start_xmit = stir_hard_xmit;
1095         net->open            = stir_net_open;
1096         net->stop            = stir_net_close;
1097         net->get_stats       = stir_net_get_stats;
1098         net->do_ioctl        = stir_net_ioctl;
1099 
1100         ret = register_netdev(net);
1101         if (ret != 0)
1102                 goto err_out2;
1103 
1104         MESSAGE("IrDA: Registered SigmaTel device %s\n", net->name);
1105 
1106         usb_set_intfdata(intf, stir);
1107 
1108         return 0;
1109 
1110 err_out2:
1111         free_netdev(net);
1112 err_out1:
1113         return ret;
1114 }
1115 
1116 /*
1117  * The current device is removed, the USB layer tell us to shut it down...
1118  */
1119 static void stir_disconnect(struct usb_interface *intf)
1120 {
1121         struct stir_cb *stir = usb_get_intfdata(intf);
1122 
1123         if (!stir)
1124                 return;
1125 
1126         unregister_netdev(stir->netdev);
1127         free_netdev(stir->netdev);
1128 
1129         usb_set_intfdata(intf, NULL);
1130 }
1131 
1132 
1133 /* Power management suspend, so power off the transmitter/receiver */
1134 static int stir_suspend(struct usb_interface *intf, u32 state)
1135 {
1136         struct stir_cb *stir = usb_get_intfdata(intf);
1137 
1138         netif_device_detach(stir->netdev);
1139         return 0;
1140 }
1141 
1142 /* Coming out of suspend, so reset hardware */
1143 static int stir_resume(struct usb_interface *intf)
1144 {
1145         struct stir_cb *stir = usb_get_intfdata(intf);
1146 
1147         netif_device_attach(stir->netdev);
1148 
1149         /* receiver restarted when send thread wakes up */
1150         return 0;
1151 }
1152 
1153 /*
1154  * USB device callbacks
1155  */
1156 static struct usb_driver irda_driver = {
1157         .owner          = THIS_MODULE,
1158         .name           = "stir4200",
1159         .probe          = stir_probe,
1160         .disconnect     = stir_disconnect,
1161         .id_table       = dongles,
1162         .suspend        = stir_suspend,
1163         .resume         = stir_resume,
1164 };
1165 
1166 /*
1167  * Module insertion
1168  */
1169 static int __init stir_init(void)
1170 {
1171         if (usb_register(&irda_driver) < 0)
1172                 return -1;
1173 
1174         MESSAGE("SigmaTel support registered\n");
1175         return 0;
1176 }
1177 module_init(stir_init);
1178 
1179 /*
1180  * Module removal
1181  */
1182 static void __exit stir_cleanup(void)
1183 {
1184         /* Deregister the driver and remove all pending instances */
1185         usb_deregister(&irda_driver);
1186 }
1187 module_exit(stir_cleanup);
1188

ubuntu@ubuntu:~$ ifconfig
eth0      Lien encap:Ethernet  HWaddr 00:0B:6A:8D:51:C8
          adr inet6: fe80::20b:6aff:fe8d:51c8/64 Scope:Lien
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:21739 errors:0 dropped:0 overruns:0 frame:0
          TX packets:20445 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:1000
          RX bytes:21419433 (20.4 MiB)  TX bytes:2515836 (2.3 MiB)
          Interruption:23 Adresse de base:0xd000

lo        Lien encap:Boucle locale
          inet adr:127.0.0.1  Masque:255.255.255.255
          adr inet6: ::1/128 Scope:Hôte
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:174735 errors:0 dropped:0 overruns:0 frame:0
          TX packets:174735 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:0
          RX bytes:15869208 (15.1 MiB)  TX bytes:15869208 (15.1 MiB)

ppp0      Lien encap:Protocole Point-à-Point
          inet adr:80.11.208.172  P-t-P:80.11.208.129  Masque:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
          RX packets:19257 errors:0 dropped:0 overruns:0 frame:0
          TX packets:17956 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 lg file transmission:3
          RX bytes:20846757 (19.8 MiB)  TX bytes:2045247 (1.9 MiB)

ifconfig

ubuntu@ubuntu:~$ lsusb
Bus 011 Device 005: ID 413c:4001 Dell Computer Corp.
Bus 011 Device 001: ID 0000:0000
Bus 010 Device 002: ID 03f0:1e11 Hewlett-Packard PSC-950
Bus 010 Device 001: ID 0000:0000
Bus 009 Device 002: ID 046d:0901 Logitech, Inc. ClickSmart 510
Bus 009 Device 001: ID 0000:0000
Bus 008 Device 001: ID 0000:0000
Bus 007 Device 001: ID 0000:0000
Bus 006 Device 005: ID 0ea0:2168 Ours Technology, Inc. Transcend JetFlash 2.0
Bus 006 Device 004: ID 066f:4200 SigmaTel, Inc. STIr4200 IrDA Bridge
Bus 006 Device 002: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0 "TetraHub"
Bus 006 Device 001: ID 0000:0000
Bus 005 Device 001: ID 0000:0000
Bus 004 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000