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/types.h>
44 #include <linux/init.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 	struct timeval	  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 */
write_reg(struct stir_cb * stir,__u16 reg,__u8 value)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 */
read_reg(struct stir_cb * stir,__u16 reg,__u8 * data,__u16 count)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 
isfir(u32 speed)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  */
stuff_fir(__u8 * p,__u8 c)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 */
wrap_fir_skb(const struct sk_buff * skb,__u8 * 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 
wrap_sir_skb(struct sk_buff * skb,__u8 * buf)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  */
fir_eof(struct stir_cb * stir)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 */
stir_fir_chars(struct stir_cb * stir,const __u8 * bytes,int len)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 */
stir_sir_chars(struct stir_cb * stir,const __u8 * bytes,int len)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 
unwrap_chars(struct stir_cb * stir,const __u8 * bytes,int length)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  */
change_speed(struct stir_cb * stir,unsigned speed)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  */
stir_hard_xmit(struct sk_buff * skb,struct net_device * netdev)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  */
fifo_txwait(struct stir_cb * stir,int space)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.  */
turnaround_delay(const struct stir_cb * stir,long us)651 static void turnaround_delay(const struct stir_cb *stir, long us)
652 {
653 	long ticks;
654 	struct timeval now;
655 
656 	if (us <= 0)
657 		return;
658 
659 	do_gettimeofday(&now);
660 	if (now.tv_sec - stir->rx_time.tv_sec > 0)
661 		us -= USEC_PER_SEC;
662 	us -= now.tv_usec - stir->rx_time.tv_usec;
663 	if (us < 10)
664 		return;
665 
666 	ticks = us / (1000000 / HZ);
667 	if (ticks > 0)
668 		schedule_timeout_interruptible(1 + ticks);
669 	else
670 		udelay(us);
671 }
672 
673 /*
674  * Start receiver by submitting a request to the receive pipe.
675  * If nothing is available it will return after rx_interval.
676  */
receive_start(struct stir_cb * stir)677 static int receive_start(struct stir_cb *stir)
678 {
679 	/* reset state */
680 	stir->receiving = 1;
681 
682 	stir->rx_buff.in_frame = FALSE;
683 	stir->rx_buff.state = OUTSIDE_FRAME;
684 
685 	stir->rx_urb->status = 0;
686 	return usb_submit_urb(stir->rx_urb, GFP_KERNEL);
687 }
688 
689 /* Stop all pending receive Urb's */
receive_stop(struct stir_cb * stir)690 static void receive_stop(struct stir_cb *stir)
691 {
692 	stir->receiving = 0;
693 	usb_kill_urb(stir->rx_urb);
694 
695 	if (stir->rx_buff.in_frame)
696 		stir->netdev->stats.collisions++;
697 }
698 /*
699  * Wrap data in socket buffer and send it.
700  */
stir_send(struct stir_cb * stir,struct sk_buff * skb)701 static void stir_send(struct stir_cb *stir, struct sk_buff *skb)
702 {
703 	unsigned wraplen;
704 	int first_frame = 0;
705 
706 	/* if receiving, need to turnaround */
707 	if (stir->receiving) {
708 		receive_stop(stir);
709 		turnaround_delay(stir, irda_get_mtt(skb));
710 		first_frame = 1;
711 	}
712 
713 	if (isfir(stir->speed))
714 		wraplen = wrap_fir_skb(skb, stir->io_buf);
715 	else
716 		wraplen = wrap_sir_skb(skb, stir->io_buf);
717 
718 	/* check for space available in fifo */
719 	if (!first_frame)
720 		fifo_txwait(stir, wraplen);
721 
722 	stir->netdev->stats.tx_packets++;
723 	stir->netdev->stats.tx_bytes += skb->len;
724 	stir->netdev->trans_start = jiffies;
725 	pr_debug("send %d (%d)\n", skb->len, wraplen);
726 
727 	if (usb_bulk_msg(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1),
728 			 stir->io_buf, wraplen,
729 			 NULL, TRANSMIT_TIMEOUT))
730 		stir->netdev->stats.tx_errors++;
731 }
732 
733 /*
734  * Transmit state machine thread
735  */
stir_transmit_thread(void * arg)736 static int stir_transmit_thread(void *arg)
737 {
738 	struct stir_cb *stir = arg;
739 	struct net_device *dev = stir->netdev;
740 	struct sk_buff *skb;
741 
742         while (!kthread_should_stop()) {
743 #ifdef CONFIG_PM
744 		/* if suspending, then power off and wait */
745 		if (unlikely(freezing(current))) {
746 			if (stir->receiving)
747 				receive_stop(stir);
748 			else
749 				fifo_txwait(stir, -1);
750 
751 			write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
752 
753 			try_to_freeze();
754 
755 			if (change_speed(stir, stir->speed))
756 				break;
757 		}
758 #endif
759 
760 		/* if something to send? */
761 		skb = xchg(&stir->tx_pending, NULL);
762 		if (skb) {
763 			unsigned new_speed = irda_get_next_speed(skb);
764 			netif_wake_queue(dev);
765 
766 			if (skb->len > 0)
767 				stir_send(stir, skb);
768 			dev_kfree_skb(skb);
769 
770 			if ((new_speed != -1) && (stir->speed != new_speed)) {
771 				if (fifo_txwait(stir, -1) ||
772 				    change_speed(stir, new_speed))
773 					break;
774 			}
775 			continue;
776 		}
777 
778 		/* nothing to send? start receiving */
779 		if (!stir->receiving &&
780 		    irda_device_txqueue_empty(dev)) {
781 			/* Wait otherwise chip gets confused. */
782 			if (fifo_txwait(stir, -1))
783 				break;
784 
785 			if (unlikely(receive_start(stir))) {
786 				if (net_ratelimit())
787 					dev_info(&dev->dev,
788 						 "%s: receive usb submit failed\n",
789 						 stir->netdev->name);
790 				stir->receiving = 0;
791 				msleep(10);
792 				continue;
793 			}
794 		}
795 
796 		/* sleep if nothing to send */
797                 set_current_state(TASK_INTERRUPTIBLE);
798                 schedule();
799 
800 	}
801         return 0;
802 }
803 
804 
805 /*
806  * USB bulk receive completion callback.
807  * Wakes up every ms (usb round trip) with wrapped
808  * data.
809  */
stir_rcv_irq(struct urb * urb)810 static void stir_rcv_irq(struct urb *urb)
811 {
812 	struct stir_cb *stir = urb->context;
813 	int err;
814 
815 	/* in process of stopping, just drop data */
816 	if (!netif_running(stir->netdev))
817 		return;
818 
819 	/* unlink, shutdown, unplug, other nasties */
820 	if (urb->status != 0)
821 		return;
822 
823 	if (urb->actual_length > 0) {
824 		pr_debug("receive %d\n", urb->actual_length);
825 		unwrap_chars(stir, urb->transfer_buffer,
826 			     urb->actual_length);
827 
828 		do_gettimeofday(&stir->rx_time);
829 	}
830 
831 	/* kernel thread is stopping receiver don't resubmit */
832 	if (!stir->receiving)
833 		return;
834 
835 	/* resubmit existing urb */
836 	err = usb_submit_urb(urb, GFP_ATOMIC);
837 
838 	/* in case of error, the kernel thread will restart us */
839 	if (err) {
840 		dev_warn(&stir->netdev->dev, "usb receive submit error: %d\n",
841 			 err);
842 		stir->receiving = 0;
843 		wake_up_process(stir->thread);
844 	}
845 }
846 
847 /*
848  * Function stir_net_open (dev)
849  *
850  *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
851  */
stir_net_open(struct net_device * netdev)852 static int stir_net_open(struct net_device *netdev)
853 {
854 	struct stir_cb *stir = netdev_priv(netdev);
855 	int err;
856 	char hwname[16];
857 
858 	err = usb_clear_halt(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1));
859 	if (err)
860 		goto err_out1;
861 	err = usb_clear_halt(stir->usbdev, usb_rcvbulkpipe(stir->usbdev, 2));
862 	if (err)
863 		goto err_out1;
864 
865 	err = change_speed(stir, 9600);
866 	if (err)
867 		goto err_out1;
868 
869 	err = -ENOMEM;
870 
871 	/* Initialize for SIR/FIR to copy data directly into skb.  */
872 	stir->receiving = 0;
873 	stir->rx_buff.truesize = IRDA_SKB_MAX_MTU;
874 	stir->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
875 	if (!stir->rx_buff.skb)
876 		goto err_out1;
877 
878 	skb_reserve(stir->rx_buff.skb, 1);
879 	stir->rx_buff.head = stir->rx_buff.skb->data;
880 	do_gettimeofday(&stir->rx_time);
881 
882 	stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
883 	if (!stir->rx_urb)
884 		goto err_out2;
885 
886 	stir->io_buf = kmalloc(STIR_FIFO_SIZE, GFP_KERNEL);
887 	if (!stir->io_buf)
888 		goto err_out3;
889 
890 	usb_fill_bulk_urb(stir->rx_urb, stir->usbdev,
891 			  usb_rcvbulkpipe(stir->usbdev, 2),
892 			  stir->io_buf, STIR_FIFO_SIZE,
893 			  stir_rcv_irq, stir);
894 
895 	stir->fifo_status = kmalloc(FIFO_REGS_SIZE, GFP_KERNEL);
896 	if (!stir->fifo_status)
897 		goto err_out4;
898 
899 	/*
900 	 * Now that everything should be initialized properly,
901 	 * Open new IrLAP layer instance to take care of us...
902 	 * Note : will send immediately a speed change...
903 	 */
904 	sprintf(hwname, "usb#%d", stir->usbdev->devnum);
905 	stir->irlap = irlap_open(netdev, &stir->qos, hwname);
906 	if (!stir->irlap) {
907 		err("stir4200: irlap_open failed");
908 		goto err_out5;
909 	}
910 
911 	/** Start kernel thread for transmit.  */
912 	stir->thread = kthread_run(stir_transmit_thread, stir,
913 				   "%s", stir->netdev->name);
914         if (IS_ERR(stir->thread)) {
915                 err = PTR_ERR(stir->thread);
916 		err("stir4200: unable to start kernel thread");
917 		goto err_out6;
918 	}
919 
920 	netif_start_queue(netdev);
921 
922 	return 0;
923 
924  err_out6:
925 	irlap_close(stir->irlap);
926  err_out5:
927 	kfree(stir->fifo_status);
928  err_out4:
929 	kfree(stir->io_buf);
930  err_out3:
931 	usb_free_urb(stir->rx_urb);
932  err_out2:
933 	kfree_skb(stir->rx_buff.skb);
934  err_out1:
935 	return err;
936 }
937 
938 /*
939  * Function stir_net_close (stir)
940  *
941  *    Network device is taken down. Usually this is done by
942  *    "ifconfig irda0 down"
943  */
stir_net_close(struct net_device * netdev)944 static int stir_net_close(struct net_device *netdev)
945 {
946 	struct stir_cb *stir = netdev_priv(netdev);
947 
948 	/* Stop transmit processing */
949 	netif_stop_queue(netdev);
950 
951 	/* Kill transmit thread */
952 	kthread_stop(stir->thread);
953 	kfree(stir->fifo_status);
954 
955 	/* Mop up receive urb's */
956 	usb_kill_urb(stir->rx_urb);
957 
958 	kfree(stir->io_buf);
959 	usb_free_urb(stir->rx_urb);
960 	kfree_skb(stir->rx_buff.skb);
961 
962 	/* Stop and remove instance of IrLAP */
963 	if (stir->irlap)
964 		irlap_close(stir->irlap);
965 
966 	stir->irlap = NULL;
967 
968 	return 0;
969 }
970 
971 /*
972  * IOCTLs : Extra out-of-band network commands...
973  */
stir_net_ioctl(struct net_device * netdev,struct ifreq * rq,int cmd)974 static int stir_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
975 {
976 	struct if_irda_req *irq = (struct if_irda_req *) rq;
977 	struct stir_cb *stir = netdev_priv(netdev);
978 	int ret = 0;
979 
980 	switch (cmd) {
981 	case SIOCSBANDWIDTH: /* Set bandwidth */
982 		if (!capable(CAP_NET_ADMIN))
983 			return -EPERM;
984 
985 		/* Check if the device is still there */
986 		if (netif_device_present(stir->netdev))
987 			ret = change_speed(stir, irq->ifr_baudrate);
988 		break;
989 
990 	case SIOCSMEDIABUSY: /* Set media busy */
991 		if (!capable(CAP_NET_ADMIN))
992 			return -EPERM;
993 
994 		/* Check if the IrDA stack is still there */
995 		if (netif_running(stir->netdev))
996 			irda_device_set_media_busy(stir->netdev, TRUE);
997 		break;
998 
999 	case SIOCGRECEIVING:
1000 		/* Only approximately true */
1001 		irq->ifr_receiving = stir->receiving;
1002 		break;
1003 
1004 	default:
1005 		ret = -EOPNOTSUPP;
1006 	}
1007 
1008 	return ret;
1009 }
1010 
1011 static const struct net_device_ops stir_netdev_ops = {
1012 	.ndo_open       = stir_net_open,
1013 	.ndo_stop       = stir_net_close,
1014 	.ndo_start_xmit = stir_hard_xmit,
1015 	.ndo_do_ioctl   = stir_net_ioctl,
1016 };
1017 
1018 /*
1019  * This routine is called by the USB subsystem for each new device
1020  * in the system. We need to check if the device is ours, and in
1021  * this case start handling it.
1022  * Note : it might be worth protecting this function by a global
1023  * spinlock... Or not, because maybe USB already deal with that...
1024  */
stir_probe(struct usb_interface * intf,const struct usb_device_id * id)1025 static int stir_probe(struct usb_interface *intf,
1026 		      const struct usb_device_id *id)
1027 {
1028 	struct usb_device *dev = interface_to_usbdev(intf);
1029 	struct stir_cb *stir = NULL;
1030 	struct net_device *net;
1031 	int ret = -ENOMEM;
1032 
1033 	/* Allocate network device container. */
1034 	net = alloc_irdadev(sizeof(*stir));
1035 	if(!net)
1036 		goto err_out1;
1037 
1038 	SET_NETDEV_DEV(net, &intf->dev);
1039 	stir = netdev_priv(net);
1040 	stir->netdev = net;
1041 	stir->usbdev = dev;
1042 
1043 	ret = usb_reset_configuration(dev);
1044 	if (ret != 0) {
1045 		err("stir4200: usb reset configuration failed");
1046 		goto err_out2;
1047 	}
1048 
1049 	printk(KERN_INFO "SigmaTel STIr4200 IRDA/USB found at address %d, "
1050 		"Vendor: %x, Product: %x\n",
1051 	       dev->devnum, le16_to_cpu(dev->descriptor.idVendor),
1052 	       le16_to_cpu(dev->descriptor.idProduct));
1053 
1054 	/* Initialize QoS for this device */
1055 	irda_init_max_qos_capabilies(&stir->qos);
1056 
1057 	/* That's the Rx capability. */
1058 	stir->qos.baud_rate.bits       &= IR_2400 | IR_9600 | IR_19200 |
1059 					 IR_38400 | IR_57600 | IR_115200 |
1060 					 (IR_4000000 << 8);
1061 	stir->qos.min_turn_time.bits   &= qos_mtt_bits;
1062 	irda_qos_bits_to_value(&stir->qos);
1063 
1064 	/* Override the network functions we need to use */
1065 	net->netdev_ops = &stir_netdev_ops;
1066 
1067 	ret = register_netdev(net);
1068 	if (ret != 0)
1069 		goto err_out2;
1070 
1071 	dev_info(&intf->dev, "IrDA: Registered SigmaTel device %s\n",
1072 		 net->name);
1073 
1074 	usb_set_intfdata(intf, stir);
1075 
1076 	return 0;
1077 
1078 err_out2:
1079 	free_netdev(net);
1080 err_out1:
1081 	return ret;
1082 }
1083 
1084 /*
1085  * The current device is removed, the USB layer tell us to shut it down...
1086  */
stir_disconnect(struct usb_interface * intf)1087 static void stir_disconnect(struct usb_interface *intf)
1088 {
1089 	struct stir_cb *stir = usb_get_intfdata(intf);
1090 
1091 	if (!stir)
1092 		return;
1093 
1094 	unregister_netdev(stir->netdev);
1095 	free_netdev(stir->netdev);
1096 
1097 	usb_set_intfdata(intf, NULL);
1098 }
1099 
1100 #ifdef CONFIG_PM
1101 /* USB suspend, so power off the transmitter/receiver */
stir_suspend(struct usb_interface * intf,pm_message_t message)1102 static int stir_suspend(struct usb_interface *intf, pm_message_t message)
1103 {
1104 	struct stir_cb *stir = usb_get_intfdata(intf);
1105 
1106 	netif_device_detach(stir->netdev);
1107 	return 0;
1108 }
1109 
1110 /* Coming out of suspend, so reset hardware */
stir_resume(struct usb_interface * intf)1111 static int stir_resume(struct usb_interface *intf)
1112 {
1113 	struct stir_cb *stir = usb_get_intfdata(intf);
1114 
1115 	netif_device_attach(stir->netdev);
1116 
1117 	/* receiver restarted when send thread wakes up */
1118 	return 0;
1119 }
1120 #endif
1121 
1122 /*
1123  * USB device callbacks
1124  */
1125 static struct usb_driver irda_driver = {
1126 	.name		= "stir4200",
1127 	.probe		= stir_probe,
1128 	.disconnect	= stir_disconnect,
1129 	.id_table	= dongles,
1130 #ifdef CONFIG_PM
1131 	.suspend	= stir_suspend,
1132 	.resume		= stir_resume,
1133 #endif
1134 };
1135 
1136 module_usb_driver(irda_driver);
1137