xref: /linux/drivers/net/ieee802154/atusb.c (revision a8fe58cec351c25e09c393bf46117c0c47b5a17c)
1 /*
2  * atusb.c - Driver for the ATUSB IEEE 802.15.4 dongle
3  *
4  * Written 2013 by Werner Almesberger <werner@almesberger.net>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation, version 2
9  *
10  * Based on at86rf230.c and spi_atusb.c.
11  * at86rf230.c is
12  * Copyright (C) 2009 Siemens AG
13  * Written by: Dmitry Eremin-Solenikov <dmitry.baryshkov@siemens.com>
14  *
15  * spi_atusb.c is
16  * Copyright (c) 2011 Richard Sharpe <realrichardsharpe@gmail.com>
17  * Copyright (c) 2011 Stefan Schmidt <stefan@datenfreihafen.org>
18  * Copyright (c) 2011 Werner Almesberger <werner@almesberger.net>
19  *
20  * USB initialization is
21  * Copyright (c) 2013 Alexander Aring <alex.aring@gmail.com>
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/module.h>
27 #include <linux/jiffies.h>
28 #include <linux/usb.h>
29 #include <linux/skbuff.h>
30 
31 #include <net/cfg802154.h>
32 #include <net/mac802154.h>
33 
34 #include "at86rf230.h"
35 #include "atusb.h"
36 
37 #define ATUSB_JEDEC_ATMEL	0x1f	/* JEDEC manufacturer ID */
38 
39 #define ATUSB_NUM_RX_URBS	4	/* allow for a bit of local latency */
40 #define ATUSB_ALLOC_DELAY_MS	100	/* delay after failed allocation */
41 #define ATUSB_TX_TIMEOUT_MS	200	/* on the air timeout */
42 
43 struct atusb {
44 	struct ieee802154_hw *hw;
45 	struct usb_device *usb_dev;
46 	int shutdown;			/* non-zero if shutting down */
47 	int err;			/* set by first error */
48 
49 	/* RX variables */
50 	struct delayed_work work;	/* memory allocations */
51 	struct usb_anchor idle_urbs;	/* URBs waiting to be submitted */
52 	struct usb_anchor rx_urbs;	/* URBs waiting for reception */
53 
54 	/* TX variables */
55 	struct usb_ctrlrequest tx_dr;
56 	struct urb *tx_urb;
57 	struct sk_buff *tx_skb;
58 	uint8_t tx_ack_seq;		/* current TX ACK sequence number */
59 };
60 
61 /* ----- USB commands without data ----------------------------------------- */
62 
63 /* To reduce the number of error checks in the code, we record the first error
64  * in atusb->err and reject all subsequent requests until the error is cleared.
65  */
66 
67 static int atusb_control_msg(struct atusb *atusb, unsigned int pipe,
68 			     __u8 request, __u8 requesttype,
69 			     __u16 value, __u16 index,
70 			     void *data, __u16 size, int timeout)
71 {
72 	struct usb_device *usb_dev = atusb->usb_dev;
73 	int ret;
74 
75 	if (atusb->err)
76 		return atusb->err;
77 
78 	ret = usb_control_msg(usb_dev, pipe, request, requesttype,
79 			      value, index, data, size, timeout);
80 	if (ret < 0) {
81 		atusb->err = ret;
82 		dev_err(&usb_dev->dev,
83 			"atusb_control_msg: req 0x%02x val 0x%x idx 0x%x, error %d\n",
84 			request, value, index, ret);
85 	}
86 	return ret;
87 }
88 
89 static int atusb_command(struct atusb *atusb, uint8_t cmd, uint8_t arg)
90 {
91 	struct usb_device *usb_dev = atusb->usb_dev;
92 
93 	dev_dbg(&usb_dev->dev, "atusb_command: cmd = 0x%x\n", cmd);
94 	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
95 				 cmd, ATUSB_REQ_TO_DEV, arg, 0, NULL, 0, 1000);
96 }
97 
98 static int atusb_write_reg(struct atusb *atusb, uint8_t reg, uint8_t value)
99 {
100 	struct usb_device *usb_dev = atusb->usb_dev;
101 
102 	dev_dbg(&usb_dev->dev, "atusb_write_reg: 0x%02x <- 0x%02x\n",
103 		reg, value);
104 	return atusb_control_msg(atusb, usb_sndctrlpipe(usb_dev, 0),
105 				 ATUSB_REG_WRITE, ATUSB_REQ_TO_DEV,
106 				 value, reg, NULL, 0, 1000);
107 }
108 
109 static int atusb_read_reg(struct atusb *atusb, uint8_t reg)
110 {
111 	struct usb_device *usb_dev = atusb->usb_dev;
112 	int ret;
113 	uint8_t value;
114 
115 	dev_dbg(&usb_dev->dev, "atusb: reg = 0x%x\n", reg);
116 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
117 				ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
118 				0, reg, &value, 1, 1000);
119 	return ret >= 0 ? value : ret;
120 }
121 
122 static int atusb_write_subreg(struct atusb *atusb, uint8_t reg, uint8_t mask,
123 			      uint8_t shift, uint8_t value)
124 {
125 	struct usb_device *usb_dev = atusb->usb_dev;
126 	uint8_t orig, tmp;
127 	int ret = 0;
128 
129 	dev_dbg(&usb_dev->dev, "atusb_write_subreg: 0x%02x <- 0x%02x\n",
130 		reg, value);
131 
132 	orig = atusb_read_reg(atusb, reg);
133 
134 	/* Write the value only into that part of the register which is allowed
135 	 * by the mask. All other bits stay as before.
136 	 */
137 	tmp = orig & ~mask;
138 	tmp |= (value << shift) & mask;
139 
140 	if (tmp != orig)
141 		ret = atusb_write_reg(atusb, reg, tmp);
142 
143 	return ret;
144 }
145 
146 static int atusb_get_and_clear_error(struct atusb *atusb)
147 {
148 	int err = atusb->err;
149 
150 	atusb->err = 0;
151 	return err;
152 }
153 
154 /* ----- skb allocation ---------------------------------------------------- */
155 
156 #define MAX_PSDU	127
157 #define MAX_RX_XFER	(1 + MAX_PSDU + 2 + 1)	/* PHR+PSDU+CRC+LQI */
158 
159 #define SKB_ATUSB(skb)	(*(struct atusb **)(skb)->cb)
160 
161 static void atusb_in(struct urb *urb);
162 
163 static int atusb_submit_rx_urb(struct atusb *atusb, struct urb *urb)
164 {
165 	struct usb_device *usb_dev = atusb->usb_dev;
166 	struct sk_buff *skb = urb->context;
167 	int ret;
168 
169 	if (!skb) {
170 		skb = alloc_skb(MAX_RX_XFER, GFP_KERNEL);
171 		if (!skb) {
172 			dev_warn_ratelimited(&usb_dev->dev,
173 					     "atusb_in: can't allocate skb\n");
174 			return -ENOMEM;
175 		}
176 		skb_put(skb, MAX_RX_XFER);
177 		SKB_ATUSB(skb) = atusb;
178 	}
179 
180 	usb_fill_bulk_urb(urb, usb_dev, usb_rcvbulkpipe(usb_dev, 1),
181 			  skb->data, MAX_RX_XFER, atusb_in, skb);
182 	usb_anchor_urb(urb, &atusb->rx_urbs);
183 
184 	ret = usb_submit_urb(urb, GFP_KERNEL);
185 	if (ret) {
186 		usb_unanchor_urb(urb);
187 		kfree_skb(skb);
188 		urb->context = NULL;
189 	}
190 	return ret;
191 }
192 
193 static void atusb_work_urbs(struct work_struct *work)
194 {
195 	struct atusb *atusb =
196 	    container_of(to_delayed_work(work), struct atusb, work);
197 	struct usb_device *usb_dev = atusb->usb_dev;
198 	struct urb *urb;
199 	int ret;
200 
201 	if (atusb->shutdown)
202 		return;
203 
204 	do {
205 		urb = usb_get_from_anchor(&atusb->idle_urbs);
206 		if (!urb)
207 			return;
208 		ret = atusb_submit_rx_urb(atusb, urb);
209 	} while (!ret);
210 
211 	usb_anchor_urb(urb, &atusb->idle_urbs);
212 	dev_warn_ratelimited(&usb_dev->dev,
213 			     "atusb_in: can't allocate/submit URB (%d)\n", ret);
214 	schedule_delayed_work(&atusb->work,
215 			      msecs_to_jiffies(ATUSB_ALLOC_DELAY_MS) + 1);
216 }
217 
218 /* ----- Asynchronous USB -------------------------------------------------- */
219 
220 static void atusb_tx_done(struct atusb *atusb, uint8_t seq)
221 {
222 	struct usb_device *usb_dev = atusb->usb_dev;
223 	uint8_t expect = atusb->tx_ack_seq;
224 
225 	dev_dbg(&usb_dev->dev, "atusb_tx_done (0x%02x/0x%02x)\n", seq, expect);
226 	if (seq == expect) {
227 		/* TODO check for ifs handling in firmware */
228 		ieee802154_xmit_complete(atusb->hw, atusb->tx_skb, false);
229 	} else {
230 		/* TODO I experience this case when atusb has a tx complete
231 		 * irq before probing, we should fix the firmware it's an
232 		 * unlikely case now that seq == expect is then true, but can
233 		 * happen and fail with a tx_skb = NULL;
234 		 */
235 		ieee802154_wake_queue(atusb->hw);
236 		if (atusb->tx_skb)
237 			dev_kfree_skb_irq(atusb->tx_skb);
238 	}
239 }
240 
241 static void atusb_in_good(struct urb *urb)
242 {
243 	struct usb_device *usb_dev = urb->dev;
244 	struct sk_buff *skb = urb->context;
245 	struct atusb *atusb = SKB_ATUSB(skb);
246 	uint8_t len, lqi;
247 
248 	if (!urb->actual_length) {
249 		dev_dbg(&usb_dev->dev, "atusb_in: zero-sized URB ?\n");
250 		return;
251 	}
252 
253 	len = *skb->data;
254 
255 	if (urb->actual_length == 1) {
256 		atusb_tx_done(atusb, len);
257 		return;
258 	}
259 
260 	if (len + 1 > urb->actual_length - 1) {
261 		dev_dbg(&usb_dev->dev, "atusb_in: frame len %d+1 > URB %u-1\n",
262 			len, urb->actual_length);
263 		return;
264 	}
265 
266 	if (!ieee802154_is_valid_psdu_len(len)) {
267 		dev_dbg(&usb_dev->dev, "atusb_in: frame corrupted\n");
268 		return;
269 	}
270 
271 	lqi = skb->data[len + 1];
272 	dev_dbg(&usb_dev->dev, "atusb_in: rx len %d lqi 0x%02x\n", len, lqi);
273 	skb_pull(skb, 1);	/* remove PHR */
274 	skb_trim(skb, len);	/* get payload only */
275 	ieee802154_rx_irqsafe(atusb->hw, skb, lqi);
276 	urb->context = NULL;	/* skb is gone */
277 }
278 
279 static void atusb_in(struct urb *urb)
280 {
281 	struct usb_device *usb_dev = urb->dev;
282 	struct sk_buff *skb = urb->context;
283 	struct atusb *atusb = SKB_ATUSB(skb);
284 
285 	dev_dbg(&usb_dev->dev, "atusb_in: status %d len %d\n",
286 		urb->status, urb->actual_length);
287 	if (urb->status) {
288 		if (urb->status == -ENOENT) { /* being killed */
289 			kfree_skb(skb);
290 			urb->context = NULL;
291 			return;
292 		}
293 		dev_dbg(&usb_dev->dev, "atusb_in: URB error %d\n", urb->status);
294 	} else {
295 		atusb_in_good(urb);
296 	}
297 
298 	usb_anchor_urb(urb, &atusb->idle_urbs);
299 	if (!atusb->shutdown)
300 		schedule_delayed_work(&atusb->work, 0);
301 }
302 
303 /* ----- URB allocation/deallocation --------------------------------------- */
304 
305 static void atusb_free_urbs(struct atusb *atusb)
306 {
307 	struct urb *urb;
308 
309 	while (1) {
310 		urb = usb_get_from_anchor(&atusb->idle_urbs);
311 		if (!urb)
312 			break;
313 		kfree_skb(urb->context);
314 		usb_free_urb(urb);
315 	}
316 }
317 
318 static int atusb_alloc_urbs(struct atusb *atusb, int n)
319 {
320 	struct urb *urb;
321 
322 	while (n) {
323 		urb = usb_alloc_urb(0, GFP_KERNEL);
324 		if (!urb) {
325 			atusb_free_urbs(atusb);
326 			return -ENOMEM;
327 		}
328 		usb_anchor_urb(urb, &atusb->idle_urbs);
329 		n--;
330 	}
331 	return 0;
332 }
333 
334 /* ----- IEEE 802.15.4 interface operations -------------------------------- */
335 
336 static void atusb_xmit_complete(struct urb *urb)
337 {
338 	dev_dbg(&urb->dev->dev, "atusb_xmit urb completed");
339 }
340 
341 static int atusb_xmit(struct ieee802154_hw *hw, struct sk_buff *skb)
342 {
343 	struct atusb *atusb = hw->priv;
344 	struct usb_device *usb_dev = atusb->usb_dev;
345 	int ret;
346 
347 	dev_dbg(&usb_dev->dev, "atusb_xmit (%d)\n", skb->len);
348 	atusb->tx_skb = skb;
349 	atusb->tx_ack_seq++;
350 	atusb->tx_dr.wIndex = cpu_to_le16(atusb->tx_ack_seq);
351 	atusb->tx_dr.wLength = cpu_to_le16(skb->len);
352 
353 	usb_fill_control_urb(atusb->tx_urb, usb_dev,
354 			     usb_sndctrlpipe(usb_dev, 0),
355 			     (unsigned char *)&atusb->tx_dr, skb->data,
356 			     skb->len, atusb_xmit_complete, NULL);
357 	ret = usb_submit_urb(atusb->tx_urb, GFP_ATOMIC);
358 	dev_dbg(&usb_dev->dev, "atusb_xmit done (%d)\n", ret);
359 	return ret;
360 }
361 
362 static int atusb_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
363 {
364 	struct atusb *atusb = hw->priv;
365 	int ret;
366 
367 	/* This implicitly sets the CCA (Clear Channel Assessment) mode to 0,
368 	 * "Mode 3a, Carrier sense OR energy above threshold".
369 	 * We should probably make this configurable. @@@
370 	 */
371 	ret = atusb_write_reg(atusb, RG_PHY_CC_CCA, channel);
372 	if (ret < 0)
373 		return ret;
374 	msleep(1);	/* @@@ ugly synchronization */
375 	return 0;
376 }
377 
378 static int atusb_ed(struct ieee802154_hw *hw, u8 *level)
379 {
380 	BUG_ON(!level);
381 	*level = 0xbe;
382 	return 0;
383 }
384 
385 static int atusb_set_hw_addr_filt(struct ieee802154_hw *hw,
386 				  struct ieee802154_hw_addr_filt *filt,
387 				  unsigned long changed)
388 {
389 	struct atusb *atusb = hw->priv;
390 	struct device *dev = &atusb->usb_dev->dev;
391 
392 	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
393 		u16 addr = le16_to_cpu(filt->short_addr);
394 
395 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for saddr\n");
396 		atusb_write_reg(atusb, RG_SHORT_ADDR_0, addr);
397 		atusb_write_reg(atusb, RG_SHORT_ADDR_1, addr >> 8);
398 	}
399 
400 	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
401 		u16 pan = le16_to_cpu(filt->pan_id);
402 
403 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for pan id\n");
404 		atusb_write_reg(atusb, RG_PAN_ID_0, pan);
405 		atusb_write_reg(atusb, RG_PAN_ID_1, pan >> 8);
406 	}
407 
408 	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
409 		u8 i, addr[IEEE802154_EXTENDED_ADDR_LEN];
410 
411 		memcpy(addr, &filt->ieee_addr, IEEE802154_EXTENDED_ADDR_LEN);
412 		dev_vdbg(dev, "atusb_set_hw_addr_filt called for IEEE addr\n");
413 		for (i = 0; i < 8; i++)
414 			atusb_write_reg(atusb, RG_IEEE_ADDR_0 + i, addr[i]);
415 	}
416 
417 	if (changed & IEEE802154_AFILT_PANC_CHANGED) {
418 		dev_vdbg(dev,
419 			 "atusb_set_hw_addr_filt called for panc change\n");
420 		if (filt->pan_coord)
421 			atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 1);
422 		else
423 			atusb_write_subreg(atusb, SR_AACK_I_AM_COORD, 0);
424 	}
425 
426 	return atusb_get_and_clear_error(atusb);
427 }
428 
429 static int atusb_start(struct ieee802154_hw *hw)
430 {
431 	struct atusb *atusb = hw->priv;
432 	struct usb_device *usb_dev = atusb->usb_dev;
433 	int ret;
434 
435 	dev_dbg(&usb_dev->dev, "atusb_start\n");
436 	schedule_delayed_work(&atusb->work, 0);
437 	atusb_command(atusb, ATUSB_RX_MODE, 1);
438 	ret = atusb_get_and_clear_error(atusb);
439 	if (ret < 0)
440 		usb_kill_anchored_urbs(&atusb->idle_urbs);
441 	return ret;
442 }
443 
444 static void atusb_stop(struct ieee802154_hw *hw)
445 {
446 	struct atusb *atusb = hw->priv;
447 	struct usb_device *usb_dev = atusb->usb_dev;
448 
449 	dev_dbg(&usb_dev->dev, "atusb_stop\n");
450 	usb_kill_anchored_urbs(&atusb->idle_urbs);
451 	atusb_command(atusb, ATUSB_RX_MODE, 0);
452 	atusb_get_and_clear_error(atusb);
453 }
454 
455 #define ATUSB_MAX_TX_POWERS 0xF
456 static const s32 atusb_powers[ATUSB_MAX_TX_POWERS + 1] = {
457 	300, 280, 230, 180, 130, 70, 0, -100, -200, -300, -400, -500, -700,
458 	-900, -1200, -1700,
459 };
460 
461 static int
462 atusb_set_txpower(struct ieee802154_hw *hw, s32 mbm)
463 {
464 	struct atusb *atusb = hw->priv;
465 	u32 i;
466 
467 	for (i = 0; i < hw->phy->supported.tx_powers_size; i++) {
468 		if (hw->phy->supported.tx_powers[i] == mbm)
469 			return atusb_write_subreg(atusb, SR_TX_PWR_23X, i);
470 	}
471 
472 	return -EINVAL;
473 }
474 
475 static int
476 atusb_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
477 {
478 	struct atusb *atusb = hw->priv;
479 	int ret;
480 
481 	if (on) {
482 		ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 1);
483 		if (ret < 0)
484 			return ret;
485 
486 		ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 1);
487 		if (ret < 0)
488 			return ret;
489 	} else {
490 		ret = atusb_write_subreg(atusb, SR_AACK_PROM_MODE, 0);
491 		if (ret < 0)
492 			return ret;
493 
494 		ret = atusb_write_subreg(atusb, SR_AACK_DIS_ACK, 0);
495 		if (ret < 0)
496 			return ret;
497 	}
498 
499 	return 0;
500 }
501 
502 static struct ieee802154_ops atusb_ops = {
503 	.owner			= THIS_MODULE,
504 	.xmit_async		= atusb_xmit,
505 	.ed			= atusb_ed,
506 	.set_channel		= atusb_channel,
507 	.start			= atusb_start,
508 	.stop			= atusb_stop,
509 	.set_hw_addr_filt	= atusb_set_hw_addr_filt,
510 	.set_txpower		= atusb_set_txpower,
511 	.set_promiscuous_mode	= atusb_set_promiscuous_mode,
512 };
513 
514 /* ----- Firmware and chip version information ----------------------------- */
515 
516 static int atusb_get_and_show_revision(struct atusb *atusb)
517 {
518 	struct usb_device *usb_dev = atusb->usb_dev;
519 	unsigned char buffer[3];
520 	int ret;
521 
522 	/* Get a couple of the ATMega Firmware values */
523 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
524 				ATUSB_ID, ATUSB_REQ_FROM_DEV, 0, 0,
525 				buffer, 3, 1000);
526 	if (ret >= 0)
527 		dev_info(&usb_dev->dev,
528 			 "Firmware: major: %u, minor: %u, hardware type: %u\n",
529 			 buffer[0], buffer[1], buffer[2]);
530 	if (buffer[0] == 0 && buffer[1] < 2) {
531 		dev_info(&usb_dev->dev,
532 			 "Firmware version (%u.%u) is predates our first public release.",
533 			 buffer[0], buffer[1]);
534 		dev_info(&usb_dev->dev, "Please update to version 0.2 or newer");
535 	}
536 
537 	return ret;
538 }
539 
540 static int atusb_get_and_show_build(struct atusb *atusb)
541 {
542 	struct usb_device *usb_dev = atusb->usb_dev;
543 	char build[ATUSB_BUILD_SIZE + 1];
544 	int ret;
545 
546 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
547 				ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
548 				build, ATUSB_BUILD_SIZE, 1000);
549 	if (ret >= 0) {
550 		build[ret] = 0;
551 		dev_info(&usb_dev->dev, "Firmware: build %s\n", build);
552 	}
553 
554 	return ret;
555 }
556 
557 static int atusb_get_and_show_chip(struct atusb *atusb)
558 {
559 	struct usb_device *usb_dev = atusb->usb_dev;
560 	uint8_t man_id_0, man_id_1, part_num, version_num;
561 	const char *chip;
562 
563 	man_id_0 = atusb_read_reg(atusb, RG_MAN_ID_0);
564 	man_id_1 = atusb_read_reg(atusb, RG_MAN_ID_1);
565 	part_num = atusb_read_reg(atusb, RG_PART_NUM);
566 	version_num = atusb_read_reg(atusb, RG_VERSION_NUM);
567 
568 	if (atusb->err)
569 		return atusb->err;
570 
571 	if ((man_id_1 << 8 | man_id_0) != ATUSB_JEDEC_ATMEL) {
572 		dev_err(&usb_dev->dev,
573 			"non-Atmel transceiver xxxx%02x%02x\n",
574 			man_id_1, man_id_0);
575 		goto fail;
576 	}
577 
578 	switch (part_num) {
579 	case 2:
580 		chip = "AT86RF230";
581 		break;
582 	case 3:
583 		chip = "AT86RF231";
584 		break;
585 	default:
586 		dev_err(&usb_dev->dev,
587 			"unexpected transceiver, part 0x%02x version 0x%02x\n",
588 			part_num, version_num);
589 		goto fail;
590 	}
591 
592 	dev_info(&usb_dev->dev, "ATUSB: %s version %d\n", chip, version_num);
593 
594 	return 0;
595 
596 fail:
597 	atusb->err = -ENODEV;
598 	return -ENODEV;
599 }
600 
601 /* ----- Setup ------------------------------------------------------------- */
602 
603 static int atusb_probe(struct usb_interface *interface,
604 		       const struct usb_device_id *id)
605 {
606 	struct usb_device *usb_dev = interface_to_usbdev(interface);
607 	struct ieee802154_hw *hw;
608 	struct atusb *atusb = NULL;
609 	int ret = -ENOMEM;
610 
611 	hw = ieee802154_alloc_hw(sizeof(struct atusb), &atusb_ops);
612 	if (!hw)
613 		return -ENOMEM;
614 
615 	atusb = hw->priv;
616 	atusb->hw = hw;
617 	atusb->usb_dev = usb_get_dev(usb_dev);
618 	usb_set_intfdata(interface, atusb);
619 
620 	atusb->shutdown = 0;
621 	atusb->err = 0;
622 	INIT_DELAYED_WORK(&atusb->work, atusb_work_urbs);
623 	init_usb_anchor(&atusb->idle_urbs);
624 	init_usb_anchor(&atusb->rx_urbs);
625 
626 	if (atusb_alloc_urbs(atusb, ATUSB_NUM_RX_URBS))
627 		goto fail;
628 
629 	atusb->tx_dr.bRequestType = ATUSB_REQ_TO_DEV;
630 	atusb->tx_dr.bRequest = ATUSB_TX;
631 	atusb->tx_dr.wValue = cpu_to_le16(0);
632 
633 	atusb->tx_urb = usb_alloc_urb(0, GFP_ATOMIC);
634 	if (!atusb->tx_urb)
635 		goto fail;
636 
637 	hw->parent = &usb_dev->dev;
638 	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM | IEEE802154_HW_AFILT |
639 		    IEEE802154_HW_PROMISCUOUS;
640 
641 	hw->phy->flags = WPAN_PHY_FLAG_TXPOWER;
642 
643 	hw->phy->current_page = 0;
644 	hw->phy->current_channel = 11;	/* reset default */
645 	hw->phy->supported.channels[0] = 0x7FFF800;
646 	hw->phy->supported.tx_powers = atusb_powers;
647 	hw->phy->supported.tx_powers_size = ARRAY_SIZE(atusb_powers);
648 	hw->phy->transmit_power = hw->phy->supported.tx_powers[0];
649 	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
650 
651 	atusb_command(atusb, ATUSB_RF_RESET, 0);
652 	atusb_get_and_show_chip(atusb);
653 	atusb_get_and_show_revision(atusb);
654 	atusb_get_and_show_build(atusb);
655 	ret = atusb_get_and_clear_error(atusb);
656 	if (ret) {
657 		dev_err(&atusb->usb_dev->dev,
658 			"%s: initialization failed, error = %d\n",
659 			__func__, ret);
660 		goto fail;
661 	}
662 
663 	ret = ieee802154_register_hw(hw);
664 	if (ret)
665 		goto fail;
666 
667 	/* If we just powered on, we're now in P_ON and need to enter TRX_OFF
668 	 * explicitly. Any resets after that will send us straight to TRX_OFF,
669 	 * making the command below redundant.
670 	 */
671 	atusb_write_reg(atusb, RG_TRX_STATE, STATE_FORCE_TRX_OFF);
672 	msleep(1);	/* reset => TRX_OFF, tTR13 = 37 us */
673 
674 #if 0
675 	/* Calculating the maximum time available to empty the frame buffer
676 	 * on reception:
677 	 *
678 	 * According to [1], the inter-frame gap is
679 	 * R * 20 * 16 us + 128 us
680 	 * where R is a random number from 0 to 7. Furthermore, we have 20 bit
681 	 * times (80 us at 250 kbps) of SHR of the next frame before the
682 	 * transceiver begins storing data in the frame buffer.
683 	 *
684 	 * This yields a minimum time of 208 us between the last data of a
685 	 * frame and the first data of the next frame. This time is further
686 	 * reduced by interrupt latency in the atusb firmware.
687 	 *
688 	 * atusb currently needs about 500 us to retrieve a maximum-sized
689 	 * frame. We therefore have to allow reception of a new frame to begin
690 	 * while we retrieve the previous frame.
691 	 *
692 	 * [1] "JN-AN-1035 Calculating data rates in an IEEE 802.15.4-based
693 	 *      network", Jennic 2006.
694 	 *     http://www.jennic.com/download_file.php?supportFile=JN-AN-1035%20Calculating%20802-15-4%20Data%20Rates-1v0.pdf
695 	 */
696 
697 	atusb_write_subreg(atusb, SR_RX_SAFE_MODE, 1);
698 #endif
699 	atusb_write_reg(atusb, RG_IRQ_MASK, 0xff);
700 
701 	ret = atusb_get_and_clear_error(atusb);
702 	if (!ret)
703 		return 0;
704 
705 	dev_err(&atusb->usb_dev->dev,
706 		"%s: setup failed, error = %d\n",
707 		__func__, ret);
708 
709 	ieee802154_unregister_hw(hw);
710 fail:
711 	atusb_free_urbs(atusb);
712 	usb_kill_urb(atusb->tx_urb);
713 	usb_free_urb(atusb->tx_urb);
714 	usb_put_dev(usb_dev);
715 	ieee802154_free_hw(hw);
716 	return ret;
717 }
718 
719 static void atusb_disconnect(struct usb_interface *interface)
720 {
721 	struct atusb *atusb = usb_get_intfdata(interface);
722 
723 	dev_dbg(&atusb->usb_dev->dev, "atusb_disconnect\n");
724 
725 	atusb->shutdown = 1;
726 	cancel_delayed_work_sync(&atusb->work);
727 
728 	usb_kill_anchored_urbs(&atusb->rx_urbs);
729 	atusb_free_urbs(atusb);
730 	usb_kill_urb(atusb->tx_urb);
731 	usb_free_urb(atusb->tx_urb);
732 
733 	ieee802154_unregister_hw(atusb->hw);
734 
735 	ieee802154_free_hw(atusb->hw);
736 
737 	usb_set_intfdata(interface, NULL);
738 	usb_put_dev(atusb->usb_dev);
739 
740 	pr_debug("atusb_disconnect done\n");
741 }
742 
743 /* The devices we work with */
744 static const struct usb_device_id atusb_device_table[] = {
745 	{
746 		.match_flags		= USB_DEVICE_ID_MATCH_DEVICE |
747 					  USB_DEVICE_ID_MATCH_INT_INFO,
748 		.idVendor		= ATUSB_VENDOR_ID,
749 		.idProduct		= ATUSB_PRODUCT_ID,
750 		.bInterfaceClass	= USB_CLASS_VENDOR_SPEC
751 	},
752 	/* end with null element */
753 	{}
754 };
755 MODULE_DEVICE_TABLE(usb, atusb_device_table);
756 
757 static struct usb_driver atusb_driver = {
758 	.name		= "atusb",
759 	.probe		= atusb_probe,
760 	.disconnect	= atusb_disconnect,
761 	.id_table	= atusb_device_table,
762 };
763 module_usb_driver(atusb_driver);
764 
765 MODULE_AUTHOR("Alexander Aring <alex.aring@gmail.com>");
766 MODULE_AUTHOR("Richard Sharpe <realrichardsharpe@gmail.com>");
767 MODULE_AUTHOR("Stefan Schmidt <stefan@datenfreihafen.org>");
768 MODULE_AUTHOR("Werner Almesberger <werner@almesberger.net>");
769 MODULE_DESCRIPTION("ATUSB IEEE 802.15.4 Driver");
770 MODULE_LICENSE("GPL");
771