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Linux/drivers/net/irda/stir4200.c

  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 
 61 MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.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_DIR = 0x10,
146         FIFOCTL_CLR = 0x08,
147         FIFOCTL_EMPTY = 0x04,
148 };
149 
150 enum StirDiagMask {
151         IRDIG_RXHIGH = 0x80,
152         IRDIG_RXLOW = 0x40,
153 };
154 
155 enum StirTestMask {
156         TEST_PLLDOWN = 0x80,
157         TEST_LOOPIR = 0x40,
158         TEST_LOOPUSB = 0x20,
159         TEST_TSTENA = 0x10,
160         TEST_TSTOSC = 0x0F,
161 };
162 
163 struct 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 */
185 static struct usb_device_id dongles[] = {
186     /* SigmaTel, Inc,  STIr4200 IrDA/USB Bridge */
187     { USB_DEVICE(0x066f, 0x4200) },
188     { }
189 };
190 
191 MODULE_DEVICE_TABLE(usb, dongles);
192 
193 /* Send control message to set dongle register */
194 static 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 */
208 static 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 
220 static 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  */
239 static 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 */
255 static 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 
296 static 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  */
315 static 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 */
377 static 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 */
458 static 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 
468 static 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 */
478 static 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  */
499 static 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  */
563 static 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  */
591 static 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.  */
651 static 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  */
674 static 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 */
687 static 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  */
698 static 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  */
733 static 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  */
807 static 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  */
849 static 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  */
941 static 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  */
971 static 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 
1008 static 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  */
1022 static 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 
1075 err_out2:
1076         free_netdev(net);
1077 err_out1:
1078         return ret;
1079 }
1080 
1081 /*
1082  * The current device is removed, the USB layer tell us to shut it down...
1083  */
1084 static 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 */
1099 static 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 */
1108 static 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  */
1122 static 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 
1133 module_usb_driver(irda_driver);
1134 

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