1 /* ZD1211 USB-WLAN driver for Linux
2  *
3  * Copyright (C) 2005-2007 Ulrich Kunitz <kune@deine-taler.de>
4  * Copyright (C) 2006-2007 Daniel Drake <dsd@gentoo.org>
5  * Copyright (C) 2006-2007 Michael Wu <flamingice@sourmilk.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/firmware.h>
24 #include <linux/device.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/skbuff.h>
28 #include <linux/usb.h>
29 #include <linux/workqueue.h>
30 #include <linux/module.h>
31 #include <net/mac80211.h>
32 #include <asm/unaligned.h>
33 
34 #include "zd_def.h"
35 #include "zd_mac.h"
36 #include "zd_usb.h"
37 
38 static struct usb_device_id usb_ids[] = {
39 	/* ZD1211 */
40 	{ USB_DEVICE(0x0105, 0x145f), .driver_info = DEVICE_ZD1211 },
41 	{ USB_DEVICE(0x0586, 0x3401), .driver_info = DEVICE_ZD1211 },
42 	{ USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
43 	{ USB_DEVICE(0x0586, 0x3407), .driver_info = DEVICE_ZD1211 },
44 	{ USB_DEVICE(0x0586, 0x3409), .driver_info = DEVICE_ZD1211 },
45 	{ USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
46 	{ USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
47 	{ USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
48 	{ USB_DEVICE(0x0ace, 0xa211), .driver_info = DEVICE_ZD1211 },
49 	{ USB_DEVICE(0x0b05, 0x170c), .driver_info = DEVICE_ZD1211 },
50 	{ USB_DEVICE(0x0b3b, 0x1630), .driver_info = DEVICE_ZD1211 },
51 	{ USB_DEVICE(0x0b3b, 0x5630), .driver_info = DEVICE_ZD1211 },
52 	{ USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
53 	{ USB_DEVICE(0x0df6, 0x9075), .driver_info = DEVICE_ZD1211 },
54 	{ USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
55 	{ USB_DEVICE(0x129b, 0x1666), .driver_info = DEVICE_ZD1211 },
56 	{ USB_DEVICE(0x13b1, 0x001e), .driver_info = DEVICE_ZD1211 },
57 	{ USB_DEVICE(0x1435, 0x0711), .driver_info = DEVICE_ZD1211 },
58 	{ USB_DEVICE(0x14ea, 0xab10), .driver_info = DEVICE_ZD1211 },
59 	{ USB_DEVICE(0x14ea, 0xab13), .driver_info = DEVICE_ZD1211 },
60 	{ USB_DEVICE(0x157e, 0x300a), .driver_info = DEVICE_ZD1211 },
61 	{ USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
62 	{ USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
63 	{ USB_DEVICE(0x157e, 0x3207), .driver_info = DEVICE_ZD1211 },
64 	{ USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
65 	{ USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
66 	/* ZD1211B */
67 	{ USB_DEVICE(0x0053, 0x5301), .driver_info = DEVICE_ZD1211B },
68 	{ USB_DEVICE(0x0409, 0x0248), .driver_info = DEVICE_ZD1211B },
69 	{ USB_DEVICE(0x0411, 0x00da), .driver_info = DEVICE_ZD1211B },
70 	{ USB_DEVICE(0x0471, 0x1236), .driver_info = DEVICE_ZD1211B },
71 	{ USB_DEVICE(0x0471, 0x1237), .driver_info = DEVICE_ZD1211B },
72 	{ USB_DEVICE(0x050d, 0x705c), .driver_info = DEVICE_ZD1211B },
73 	{ USB_DEVICE(0x054c, 0x0257), .driver_info = DEVICE_ZD1211B },
74 	{ USB_DEVICE(0x0586, 0x340a), .driver_info = DEVICE_ZD1211B },
75 	{ USB_DEVICE(0x0586, 0x340f), .driver_info = DEVICE_ZD1211B },
76 	{ USB_DEVICE(0x0586, 0x3410), .driver_info = DEVICE_ZD1211B },
77 	{ USB_DEVICE(0x0586, 0x3412), .driver_info = DEVICE_ZD1211B },
78 	{ USB_DEVICE(0x0586, 0x3413), .driver_info = DEVICE_ZD1211B },
79 	{ USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
80 	{ USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211B },
81 	{ USB_DEVICE(0x07fa, 0x1196), .driver_info = DEVICE_ZD1211B },
82 	{ USB_DEVICE(0x083a, 0x4505), .driver_info = DEVICE_ZD1211B },
83 	{ USB_DEVICE(0x083a, 0xe501), .driver_info = DEVICE_ZD1211B },
84 	{ USB_DEVICE(0x083a, 0xe503), .driver_info = DEVICE_ZD1211B },
85 	{ USB_DEVICE(0x083a, 0xe506), .driver_info = DEVICE_ZD1211B },
86 	{ USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
87 	{ USB_DEVICE(0x0ace, 0xb215), .driver_info = DEVICE_ZD1211B },
88 	{ USB_DEVICE(0x0b05, 0x171b), .driver_info = DEVICE_ZD1211B },
89 	{ USB_DEVICE(0x0baf, 0x0121), .driver_info = DEVICE_ZD1211B },
90 	{ USB_DEVICE(0x0cde, 0x001a), .driver_info = DEVICE_ZD1211B },
91 	{ USB_DEVICE(0x0df6, 0x0036), .driver_info = DEVICE_ZD1211B },
92 	{ USB_DEVICE(0x129b, 0x1667), .driver_info = DEVICE_ZD1211B },
93 	{ USB_DEVICE(0x13b1, 0x0024), .driver_info = DEVICE_ZD1211B },
94 	{ USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
95 	{ USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
96 	{ USB_DEVICE(0x2019, 0x5303), .driver_info = DEVICE_ZD1211B },
97 	{ USB_DEVICE(0x2019, 0xed01), .driver_info = DEVICE_ZD1211B },
98 	/* "Driverless" devices that need ejecting */
99 	{ USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
100 	{ USB_DEVICE(0x0ace, 0x20ff), .driver_info = DEVICE_INSTALLER },
101 	{}
102 };
103 
104 MODULE_LICENSE("GPL");
105 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
106 MODULE_AUTHOR("Ulrich Kunitz");
107 MODULE_AUTHOR("Daniel Drake");
108 MODULE_VERSION("1.0");
109 MODULE_DEVICE_TABLE(usb, usb_ids);
110 
111 #define FW_ZD1211_PREFIX	"zd1211/zd1211_"
112 #define FW_ZD1211B_PREFIX	"zd1211/zd1211b_"
113 
114 static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req,
115 			    unsigned int count);
116 
117 /* USB device initialization */
118 static void int_urb_complete(struct urb *urb);
119 
120 static int request_fw_file(
121 	const struct firmware **fw, const char *name, struct device *device)
122 {
123 	int r;
124 
125 	dev_dbg_f(device, "fw name %s\n", name);
126 
127 	r = request_firmware(fw, name, device);
128 	if (r)
129 		dev_err(device,
130 		       "Could not load firmware file %s. Error number %d\n",
131 		       name, r);
132 	return r;
133 }
134 
135 static inline u16 get_bcdDevice(const struct usb_device *udev)
136 {
137 	return le16_to_cpu(udev->descriptor.bcdDevice);
138 }
139 
140 enum upload_code_flags {
141 	REBOOT = 1,
142 };
143 
144 /* Ensures that MAX_TRANSFER_SIZE is even. */
145 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
146 
147 static int upload_code(struct usb_device *udev,
148 	const u8 *data, size_t size, u16 code_offset, int flags)
149 {
150 	u8 *p;
151 	int r;
152 
153 	/* USB request blocks need "kmalloced" buffers.
154 	 */
155 	p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
156 	if (!p) {
157 		r = -ENOMEM;
158 		goto error;
159 	}
160 
161 	size &= ~1;
162 	while (size > 0) {
163 		size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
164 			size : MAX_TRANSFER_SIZE;
165 
166 		dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
167 
168 		memcpy(p, data, transfer_size);
169 		r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
170 			USB_REQ_FIRMWARE_DOWNLOAD,
171 			USB_DIR_OUT | USB_TYPE_VENDOR,
172 			code_offset, 0, p, transfer_size, 1000 /* ms */);
173 		if (r < 0) {
174 			dev_err(&udev->dev,
175 			       "USB control request for firmware upload"
176 			       " failed. Error number %d\n", r);
177 			goto error;
178 		}
179 		transfer_size = r & ~1;
180 
181 		size -= transfer_size;
182 		data += transfer_size;
183 		code_offset += transfer_size/sizeof(u16);
184 	}
185 
186 	if (flags & REBOOT) {
187 		u8 ret;
188 
189 		/* Use "DMA-aware" buffer. */
190 		r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
191 			USB_REQ_FIRMWARE_CONFIRM,
192 			USB_DIR_IN | USB_TYPE_VENDOR,
193 			0, 0, p, sizeof(ret), 5000 /* ms */);
194 		if (r != sizeof(ret)) {
195 			dev_err(&udev->dev,
196 				"control request firmware confirmation failed."
197 				" Return value %d\n", r);
198 			if (r >= 0)
199 				r = -ENODEV;
200 			goto error;
201 		}
202 		ret = p[0];
203 		if (ret & 0x80) {
204 			dev_err(&udev->dev,
205 				"Internal error while downloading."
206 				" Firmware confirm return value %#04x\n",
207 				(unsigned int)ret);
208 			r = -ENODEV;
209 			goto error;
210 		}
211 		dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
212 			(unsigned int)ret);
213 	}
214 
215 	r = 0;
216 error:
217 	kfree(p);
218 	return r;
219 }
220 
221 static u16 get_word(const void *data, u16 offset)
222 {
223 	const __le16 *p = data;
224 	return le16_to_cpu(p[offset]);
225 }
226 
227 static char *get_fw_name(struct zd_usb *usb, char *buffer, size_t size,
228 	               const char* postfix)
229 {
230 	scnprintf(buffer, size, "%s%s",
231 		usb->is_zd1211b ?
232 			FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
233 		postfix);
234 	return buffer;
235 }
236 
237 static int handle_version_mismatch(struct zd_usb *usb,
238 	const struct firmware *ub_fw)
239 {
240 	struct usb_device *udev = zd_usb_to_usbdev(usb);
241 	const struct firmware *ur_fw = NULL;
242 	int offset;
243 	int r = 0;
244 	char fw_name[128];
245 
246 	r = request_fw_file(&ur_fw,
247 		get_fw_name(usb, fw_name, sizeof(fw_name), "ur"),
248 		&udev->dev);
249 	if (r)
250 		goto error;
251 
252 	r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
253 	if (r)
254 		goto error;
255 
256 	offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
257 	r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
258 		E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
259 
260 	/* At this point, the vendor driver downloads the whole firmware
261 	 * image, hacks around with version IDs, and uploads it again,
262 	 * completely overwriting the boot code. We do not do this here as
263 	 * it is not required on any tested devices, and it is suspected to
264 	 * cause problems. */
265 error:
266 	release_firmware(ur_fw);
267 	return r;
268 }
269 
270 static int upload_firmware(struct zd_usb *usb)
271 {
272 	int r;
273 	u16 fw_bcdDevice;
274 	u16 bcdDevice;
275 	struct usb_device *udev = zd_usb_to_usbdev(usb);
276 	const struct firmware *ub_fw = NULL;
277 	const struct firmware *uph_fw = NULL;
278 	char fw_name[128];
279 
280 	bcdDevice = get_bcdDevice(udev);
281 
282 	r = request_fw_file(&ub_fw,
283 		get_fw_name(usb, fw_name, sizeof(fw_name), "ub"),
284 		&udev->dev);
285 	if (r)
286 		goto error;
287 
288 	fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
289 
290 	if (fw_bcdDevice != bcdDevice) {
291 		dev_info(&udev->dev,
292 			"firmware version %#06x and device bootcode version "
293 			"%#06x differ\n", fw_bcdDevice, bcdDevice);
294 		if (bcdDevice <= 0x4313)
295 			dev_warn(&udev->dev, "device has old bootcode, please "
296 				"report success or failure\n");
297 
298 		r = handle_version_mismatch(usb, ub_fw);
299 		if (r)
300 			goto error;
301 	} else {
302 		dev_dbg_f(&udev->dev,
303 			"firmware device id %#06x is equal to the "
304 			"actual device id\n", fw_bcdDevice);
305 	}
306 
307 
308 	r = request_fw_file(&uph_fw,
309 		get_fw_name(usb, fw_name, sizeof(fw_name), "uphr"),
310 		&udev->dev);
311 	if (r)
312 		goto error;
313 
314 	r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
315 	if (r) {
316 		dev_err(&udev->dev,
317 			"Could not upload firmware code uph. Error number %d\n",
318 			r);
319 	}
320 
321 	/* FALL-THROUGH */
322 error:
323 	release_firmware(ub_fw);
324 	release_firmware(uph_fw);
325 	return r;
326 }
327 
328 MODULE_FIRMWARE(FW_ZD1211B_PREFIX "ur");
329 MODULE_FIRMWARE(FW_ZD1211_PREFIX "ur");
330 MODULE_FIRMWARE(FW_ZD1211B_PREFIX "ub");
331 MODULE_FIRMWARE(FW_ZD1211_PREFIX "ub");
332 MODULE_FIRMWARE(FW_ZD1211B_PREFIX "uphr");
333 MODULE_FIRMWARE(FW_ZD1211_PREFIX "uphr");
334 
335 /* Read data from device address space using "firmware interface" which does
336  * not require firmware to be loaded. */
337 int zd_usb_read_fw(struct zd_usb *usb, zd_addr_t addr, u8 *data, u16 len)
338 {
339 	int r;
340 	struct usb_device *udev = zd_usb_to_usbdev(usb);
341 	u8 *buf;
342 
343 	/* Use "DMA-aware" buffer. */
344 	buf = kmalloc(len, GFP_KERNEL);
345 	if (!buf)
346 		return -ENOMEM;
347 	r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
348 		USB_REQ_FIRMWARE_READ_DATA, USB_DIR_IN | 0x40, addr, 0,
349 		buf, len, 5000);
350 	if (r < 0) {
351 		dev_err(&udev->dev,
352 			"read over firmware interface failed: %d\n", r);
353 		goto exit;
354 	} else if (r != len) {
355 		dev_err(&udev->dev,
356 			"incomplete read over firmware interface: %d/%d\n",
357 			r, len);
358 		r = -EIO;
359 		goto exit;
360 	}
361 	r = 0;
362 	memcpy(data, buf, len);
363 exit:
364 	kfree(buf);
365 	return r;
366 }
367 
368 #define urb_dev(urb) (&(urb)->dev->dev)
369 
370 static inline void handle_regs_int_override(struct urb *urb)
371 {
372 	struct zd_usb *usb = urb->context;
373 	struct zd_usb_interrupt *intr = &usb->intr;
374 
375 	spin_lock(&intr->lock);
376 	if (atomic_read(&intr->read_regs_enabled)) {
377 		atomic_set(&intr->read_regs_enabled, 0);
378 		intr->read_regs_int_overridden = 1;
379 		complete(&intr->read_regs.completion);
380 	}
381 	spin_unlock(&intr->lock);
382 }
383 
384 static inline void handle_regs_int(struct urb *urb)
385 {
386 	struct zd_usb *usb = urb->context;
387 	struct zd_usb_interrupt *intr = &usb->intr;
388 	int len;
389 	u16 int_num;
390 
391 	ZD_ASSERT(in_interrupt());
392 	spin_lock(&intr->lock);
393 
394 	int_num = le16_to_cpu(*(__le16 *)(urb->transfer_buffer+2));
395 	if (int_num == CR_INTERRUPT) {
396 		struct zd_mac *mac = zd_hw_mac(zd_usb_to_hw(urb->context));
397 		spin_lock(&mac->lock);
398 		memcpy(&mac->intr_buffer, urb->transfer_buffer,
399 				USB_MAX_EP_INT_BUFFER);
400 		spin_unlock(&mac->lock);
401 		schedule_work(&mac->process_intr);
402 	} else if (atomic_read(&intr->read_regs_enabled)) {
403 		len = urb->actual_length;
404 		intr->read_regs.length = urb->actual_length;
405 		if (len > sizeof(intr->read_regs.buffer))
406 			len = sizeof(intr->read_regs.buffer);
407 
408 		memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
409 
410 		/* Sometimes USB_INT_ID_REGS is not overridden, but comes after
411 		 * USB_INT_ID_RETRY_FAILED. Read-reg retry then gets this
412 		 * delayed USB_INT_ID_REGS, but leaves USB_INT_ID_REGS of
413 		 * retry unhandled. Next read-reg command then might catch
414 		 * this wrong USB_INT_ID_REGS. Fix by ignoring wrong reads.
415 		 */
416 		if (!check_read_regs(usb, intr->read_regs.req,
417 						intr->read_regs.req_count))
418 			goto out;
419 
420 		atomic_set(&intr->read_regs_enabled, 0);
421 		intr->read_regs_int_overridden = 0;
422 		complete(&intr->read_regs.completion);
423 
424 		goto out;
425 	}
426 
427 out:
428 	spin_unlock(&intr->lock);
429 
430 	/* CR_INTERRUPT might override read_reg too. */
431 	if (int_num == CR_INTERRUPT && atomic_read(&intr->read_regs_enabled))
432 		handle_regs_int_override(urb);
433 }
434 
435 static void int_urb_complete(struct urb *urb)
436 {
437 	int r;
438 	struct usb_int_header *hdr;
439 	struct zd_usb *usb;
440 	struct zd_usb_interrupt *intr;
441 
442 	switch (urb->status) {
443 	case 0:
444 		break;
445 	case -ESHUTDOWN:
446 	case -EINVAL:
447 	case -ENODEV:
448 	case -ENOENT:
449 	case -ECONNRESET:
450 	case -EPIPE:
451 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
452 		return;
453 	default:
454 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
455 		goto resubmit;
456 	}
457 
458 	if (urb->actual_length < sizeof(hdr)) {
459 		dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
460 		goto resubmit;
461 	}
462 
463 	hdr = urb->transfer_buffer;
464 	if (hdr->type != USB_INT_TYPE) {
465 		dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
466 		goto resubmit;
467 	}
468 
469 	/* USB_INT_ID_RETRY_FAILED triggered by tx-urb submit can override
470 	 * pending USB_INT_ID_REGS causing read command timeout.
471 	 */
472 	usb = urb->context;
473 	intr = &usb->intr;
474 	if (hdr->id != USB_INT_ID_REGS && atomic_read(&intr->read_regs_enabled))
475 		handle_regs_int_override(urb);
476 
477 	switch (hdr->id) {
478 	case USB_INT_ID_REGS:
479 		handle_regs_int(urb);
480 		break;
481 	case USB_INT_ID_RETRY_FAILED:
482 		zd_mac_tx_failed(urb);
483 		break;
484 	default:
485 		dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
486 			(unsigned int)hdr->id);
487 		goto resubmit;
488 	}
489 
490 resubmit:
491 	r = usb_submit_urb(urb, GFP_ATOMIC);
492 	if (r) {
493 		dev_dbg_f(urb_dev(urb), "error: resubmit urb %p err code %d\n",
494 			  urb, r);
495 		/* TODO: add worker to reset intr->urb */
496 	}
497 	return;
498 }
499 
500 static inline int int_urb_interval(struct usb_device *udev)
501 {
502 	switch (udev->speed) {
503 	case USB_SPEED_HIGH:
504 		return 4;
505 	case USB_SPEED_LOW:
506 		return 10;
507 	case USB_SPEED_FULL:
508 	default:
509 		return 1;
510 	}
511 }
512 
513 static inline int usb_int_enabled(struct zd_usb *usb)
514 {
515 	unsigned long flags;
516 	struct zd_usb_interrupt *intr = &usb->intr;
517 	struct urb *urb;
518 
519 	spin_lock_irqsave(&intr->lock, flags);
520 	urb = intr->urb;
521 	spin_unlock_irqrestore(&intr->lock, flags);
522 	return urb != NULL;
523 }
524 
525 int zd_usb_enable_int(struct zd_usb *usb)
526 {
527 	int r;
528 	struct usb_device *udev = zd_usb_to_usbdev(usb);
529 	struct zd_usb_interrupt *intr = &usb->intr;
530 	struct urb *urb;
531 
532 	dev_dbg_f(zd_usb_dev(usb), "\n");
533 
534 	urb = usb_alloc_urb(0, GFP_KERNEL);
535 	if (!urb) {
536 		r = -ENOMEM;
537 		goto out;
538 	}
539 
540 	ZD_ASSERT(!irqs_disabled());
541 	spin_lock_irq(&intr->lock);
542 	if (intr->urb) {
543 		spin_unlock_irq(&intr->lock);
544 		r = 0;
545 		goto error_free_urb;
546 	}
547 	intr->urb = urb;
548 	spin_unlock_irq(&intr->lock);
549 
550 	r = -ENOMEM;
551 	intr->buffer = usb_alloc_coherent(udev, USB_MAX_EP_INT_BUFFER,
552 					  GFP_KERNEL, &intr->buffer_dma);
553 	if (!intr->buffer) {
554 		dev_dbg_f(zd_usb_dev(usb),
555 			"couldn't allocate transfer_buffer\n");
556 		goto error_set_urb_null;
557 	}
558 
559 	usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
560 			 intr->buffer, USB_MAX_EP_INT_BUFFER,
561 			 int_urb_complete, usb,
562 			 intr->interval);
563 	urb->transfer_dma = intr->buffer_dma;
564 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
565 
566 	dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
567 	r = usb_submit_urb(urb, GFP_KERNEL);
568 	if (r) {
569 		dev_dbg_f(zd_usb_dev(usb),
570 			 "Couldn't submit urb. Error number %d\n", r);
571 		goto error;
572 	}
573 
574 	return 0;
575 error:
576 	usb_free_coherent(udev, USB_MAX_EP_INT_BUFFER,
577 			  intr->buffer, intr->buffer_dma);
578 error_set_urb_null:
579 	spin_lock_irq(&intr->lock);
580 	intr->urb = NULL;
581 	spin_unlock_irq(&intr->lock);
582 error_free_urb:
583 	usb_free_urb(urb);
584 out:
585 	return r;
586 }
587 
588 void zd_usb_disable_int(struct zd_usb *usb)
589 {
590 	unsigned long flags;
591 	struct usb_device *udev = zd_usb_to_usbdev(usb);
592 	struct zd_usb_interrupt *intr = &usb->intr;
593 	struct urb *urb;
594 	void *buffer;
595 	dma_addr_t buffer_dma;
596 
597 	spin_lock_irqsave(&intr->lock, flags);
598 	urb = intr->urb;
599 	if (!urb) {
600 		spin_unlock_irqrestore(&intr->lock, flags);
601 		return;
602 	}
603 	intr->urb = NULL;
604 	buffer = intr->buffer;
605 	buffer_dma = intr->buffer_dma;
606 	intr->buffer = NULL;
607 	spin_unlock_irqrestore(&intr->lock, flags);
608 
609 	usb_kill_urb(urb);
610 	dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
611 	usb_free_urb(urb);
612 
613 	if (buffer)
614 		usb_free_coherent(udev, USB_MAX_EP_INT_BUFFER,
615 				  buffer, buffer_dma);
616 }
617 
618 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
619 			     unsigned int length)
620 {
621 	int i;
622 	const struct rx_length_info *length_info;
623 
624 	if (length < sizeof(struct rx_length_info)) {
625 		/* It's not a complete packet anyhow. */
626 		dev_dbg_f(zd_usb_dev(usb), "invalid, small RX packet : %d\n",
627 					   length);
628 		return;
629 	}
630 	length_info = (struct rx_length_info *)
631 		(buffer + length - sizeof(struct rx_length_info));
632 
633 	/* It might be that three frames are merged into a single URB
634 	 * transaction. We have to check for the length info tag.
635 	 *
636 	 * While testing we discovered that length_info might be unaligned,
637 	 * because if USB transactions are merged, the last packet will not
638 	 * be padded. Unaligned access might also happen if the length_info
639 	 * structure is not present.
640 	 */
641 	if (get_unaligned_le16(&length_info->tag) == RX_LENGTH_INFO_TAG)
642 	{
643 		unsigned int l, k, n;
644 		for (i = 0, l = 0;; i++) {
645 			k = get_unaligned_le16(&length_info->length[i]);
646 			if (k == 0)
647 				return;
648 			n = l+k;
649 			if (n > length)
650 				return;
651 			zd_mac_rx(zd_usb_to_hw(usb), buffer+l, k);
652 			if (i >= 2)
653 				return;
654 			l = (n+3) & ~3;
655 		}
656 	} else {
657 		zd_mac_rx(zd_usb_to_hw(usb), buffer, length);
658 	}
659 }
660 
661 static void rx_urb_complete(struct urb *urb)
662 {
663 	int r;
664 	struct zd_usb *usb;
665 	struct zd_usb_rx *rx;
666 	const u8 *buffer;
667 	unsigned int length;
668 
669 	switch (urb->status) {
670 	case 0:
671 		break;
672 	case -ESHUTDOWN:
673 	case -EINVAL:
674 	case -ENODEV:
675 	case -ENOENT:
676 	case -ECONNRESET:
677 	case -EPIPE:
678 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
679 		return;
680 	default:
681 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
682 		goto resubmit;
683 	}
684 
685 	buffer = urb->transfer_buffer;
686 	length = urb->actual_length;
687 	usb = urb->context;
688 	rx = &usb->rx;
689 
690 	tasklet_schedule(&rx->reset_timer_tasklet);
691 
692 	if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
693 		/* If there is an old first fragment, we don't care. */
694 		dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
695 		ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
696 		spin_lock(&rx->lock);
697 		memcpy(rx->fragment, buffer, length);
698 		rx->fragment_length = length;
699 		spin_unlock(&rx->lock);
700 		goto resubmit;
701 	}
702 
703 	spin_lock(&rx->lock);
704 	if (rx->fragment_length > 0) {
705 		/* We are on a second fragment, we believe */
706 		ZD_ASSERT(length + rx->fragment_length <=
707 			  ARRAY_SIZE(rx->fragment));
708 		dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
709 		memcpy(rx->fragment+rx->fragment_length, buffer, length);
710 		handle_rx_packet(usb, rx->fragment,
711 			         rx->fragment_length + length);
712 		rx->fragment_length = 0;
713 		spin_unlock(&rx->lock);
714 	} else {
715 		spin_unlock(&rx->lock);
716 		handle_rx_packet(usb, buffer, length);
717 	}
718 
719 resubmit:
720 	r = usb_submit_urb(urb, GFP_ATOMIC);
721 	if (r)
722 		dev_dbg_f(urb_dev(urb), "urb %p resubmit error %d\n", urb, r);
723 }
724 
725 static struct urb *alloc_rx_urb(struct zd_usb *usb)
726 {
727 	struct usb_device *udev = zd_usb_to_usbdev(usb);
728 	struct urb *urb;
729 	void *buffer;
730 
731 	urb = usb_alloc_urb(0, GFP_KERNEL);
732 	if (!urb)
733 		return NULL;
734 	buffer = usb_alloc_coherent(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
735 				    &urb->transfer_dma);
736 	if (!buffer) {
737 		usb_free_urb(urb);
738 		return NULL;
739 	}
740 
741 	usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
742 			  buffer, USB_MAX_RX_SIZE,
743 			  rx_urb_complete, usb);
744 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
745 
746 	return urb;
747 }
748 
749 static void free_rx_urb(struct urb *urb)
750 {
751 	if (!urb)
752 		return;
753 	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
754 			  urb->transfer_buffer, urb->transfer_dma);
755 	usb_free_urb(urb);
756 }
757 
758 static int __zd_usb_enable_rx(struct zd_usb *usb)
759 {
760 	int i, r;
761 	struct zd_usb_rx *rx = &usb->rx;
762 	struct urb **urbs;
763 
764 	dev_dbg_f(zd_usb_dev(usb), "\n");
765 
766 	r = -ENOMEM;
767 	urbs = kcalloc(RX_URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
768 	if (!urbs)
769 		goto error;
770 	for (i = 0; i < RX_URBS_COUNT; i++) {
771 		urbs[i] = alloc_rx_urb(usb);
772 		if (!urbs[i])
773 			goto error;
774 	}
775 
776 	ZD_ASSERT(!irqs_disabled());
777 	spin_lock_irq(&rx->lock);
778 	if (rx->urbs) {
779 		spin_unlock_irq(&rx->lock);
780 		r = 0;
781 		goto error;
782 	}
783 	rx->urbs = urbs;
784 	rx->urbs_count = RX_URBS_COUNT;
785 	spin_unlock_irq(&rx->lock);
786 
787 	for (i = 0; i < RX_URBS_COUNT; i++) {
788 		r = usb_submit_urb(urbs[i], GFP_KERNEL);
789 		if (r)
790 			goto error_submit;
791 	}
792 
793 	return 0;
794 error_submit:
795 	for (i = 0; i < RX_URBS_COUNT; i++) {
796 		usb_kill_urb(urbs[i]);
797 	}
798 	spin_lock_irq(&rx->lock);
799 	rx->urbs = NULL;
800 	rx->urbs_count = 0;
801 	spin_unlock_irq(&rx->lock);
802 error:
803 	if (urbs) {
804 		for (i = 0; i < RX_URBS_COUNT; i++)
805 			free_rx_urb(urbs[i]);
806 	}
807 	return r;
808 }
809 
810 int zd_usb_enable_rx(struct zd_usb *usb)
811 {
812 	int r;
813 	struct zd_usb_rx *rx = &usb->rx;
814 
815 	mutex_lock(&rx->setup_mutex);
816 	r = __zd_usb_enable_rx(usb);
817 	mutex_unlock(&rx->setup_mutex);
818 
819 	zd_usb_reset_rx_idle_timer(usb);
820 
821 	return r;
822 }
823 
824 static void __zd_usb_disable_rx(struct zd_usb *usb)
825 {
826 	int i;
827 	unsigned long flags;
828 	struct urb **urbs;
829 	unsigned int count;
830 	struct zd_usb_rx *rx = &usb->rx;
831 
832 	spin_lock_irqsave(&rx->lock, flags);
833 	urbs = rx->urbs;
834 	count = rx->urbs_count;
835 	spin_unlock_irqrestore(&rx->lock, flags);
836 	if (!urbs)
837 		return;
838 
839 	for (i = 0; i < count; i++) {
840 		usb_kill_urb(urbs[i]);
841 		free_rx_urb(urbs[i]);
842 	}
843 	kfree(urbs);
844 
845 	spin_lock_irqsave(&rx->lock, flags);
846 	rx->urbs = NULL;
847 	rx->urbs_count = 0;
848 	spin_unlock_irqrestore(&rx->lock, flags);
849 }
850 
851 void zd_usb_disable_rx(struct zd_usb *usb)
852 {
853 	struct zd_usb_rx *rx = &usb->rx;
854 
855 	mutex_lock(&rx->setup_mutex);
856 	__zd_usb_disable_rx(usb);
857 	mutex_unlock(&rx->setup_mutex);
858 
859 	tasklet_kill(&rx->reset_timer_tasklet);
860 	cancel_delayed_work_sync(&rx->idle_work);
861 }
862 
863 static void zd_usb_reset_rx(struct zd_usb *usb)
864 {
865 	bool do_reset;
866 	struct zd_usb_rx *rx = &usb->rx;
867 	unsigned long flags;
868 
869 	mutex_lock(&rx->setup_mutex);
870 
871 	spin_lock_irqsave(&rx->lock, flags);
872 	do_reset = rx->urbs != NULL;
873 	spin_unlock_irqrestore(&rx->lock, flags);
874 
875 	if (do_reset) {
876 		__zd_usb_disable_rx(usb);
877 		__zd_usb_enable_rx(usb);
878 	}
879 
880 	mutex_unlock(&rx->setup_mutex);
881 
882 	if (do_reset)
883 		zd_usb_reset_rx_idle_timer(usb);
884 }
885 
886 /**
887  * zd_usb_disable_tx - disable transmission
888  * @usb: the zd1211rw-private USB structure
889  *
890  * Frees all URBs in the free list and marks the transmission as disabled.
891  */
892 void zd_usb_disable_tx(struct zd_usb *usb)
893 {
894 	struct zd_usb_tx *tx = &usb->tx;
895 	unsigned long flags;
896 
897 	atomic_set(&tx->enabled, 0);
898 
899 	/* kill all submitted tx-urbs */
900 	usb_kill_anchored_urbs(&tx->submitted);
901 
902 	spin_lock_irqsave(&tx->lock, flags);
903 	WARN_ON(!skb_queue_empty(&tx->submitted_skbs));
904 	WARN_ON(tx->submitted_urbs != 0);
905 	tx->submitted_urbs = 0;
906 	spin_unlock_irqrestore(&tx->lock, flags);
907 
908 	/* The stopped state is ignored, relying on ieee80211_wake_queues()
909 	 * in a potentionally following zd_usb_enable_tx().
910 	 */
911 }
912 
913 /**
914  * zd_usb_enable_tx - enables transmission
915  * @usb: a &struct zd_usb pointer
916  *
917  * This function enables transmission and prepares the &zd_usb_tx data
918  * structure.
919  */
920 void zd_usb_enable_tx(struct zd_usb *usb)
921 {
922 	unsigned long flags;
923 	struct zd_usb_tx *tx = &usb->tx;
924 
925 	spin_lock_irqsave(&tx->lock, flags);
926 	atomic_set(&tx->enabled, 1);
927 	tx->submitted_urbs = 0;
928 	ieee80211_wake_queues(zd_usb_to_hw(usb));
929 	tx->stopped = 0;
930 	spin_unlock_irqrestore(&tx->lock, flags);
931 }
932 
933 static void tx_dec_submitted_urbs(struct zd_usb *usb)
934 {
935 	struct zd_usb_tx *tx = &usb->tx;
936 	unsigned long flags;
937 
938 	spin_lock_irqsave(&tx->lock, flags);
939 	--tx->submitted_urbs;
940 	if (tx->stopped && tx->submitted_urbs <= ZD_USB_TX_LOW) {
941 		ieee80211_wake_queues(zd_usb_to_hw(usb));
942 		tx->stopped = 0;
943 	}
944 	spin_unlock_irqrestore(&tx->lock, flags);
945 }
946 
947 static void tx_inc_submitted_urbs(struct zd_usb *usb)
948 {
949 	struct zd_usb_tx *tx = &usb->tx;
950 	unsigned long flags;
951 
952 	spin_lock_irqsave(&tx->lock, flags);
953 	++tx->submitted_urbs;
954 	if (!tx->stopped && tx->submitted_urbs > ZD_USB_TX_HIGH) {
955 		ieee80211_stop_queues(zd_usb_to_hw(usb));
956 		tx->stopped = 1;
957 	}
958 	spin_unlock_irqrestore(&tx->lock, flags);
959 }
960 
961 /**
962  * tx_urb_complete - completes the execution of an URB
963  * @urb: a URB
964  *
965  * This function is called if the URB has been transferred to a device or an
966  * error has happened.
967  */
968 static void tx_urb_complete(struct urb *urb)
969 {
970 	int r;
971 	struct sk_buff *skb;
972 	struct ieee80211_tx_info *info;
973 	struct zd_usb *usb;
974 	struct zd_usb_tx *tx;
975 
976 	skb = (struct sk_buff *)urb->context;
977 	info = IEEE80211_SKB_CB(skb);
978 	/*
979 	 * grab 'usb' pointer before handing off the skb (since
980 	 * it might be freed by zd_mac_tx_to_dev or mac80211)
981 	 */
982 	usb = &zd_hw_mac(info->rate_driver_data[0])->chip.usb;
983 	tx = &usb->tx;
984 
985 	switch (urb->status) {
986 	case 0:
987 		break;
988 	case -ESHUTDOWN:
989 	case -EINVAL:
990 	case -ENODEV:
991 	case -ENOENT:
992 	case -ECONNRESET:
993 	case -EPIPE:
994 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
995 		break;
996 	default:
997 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
998 		goto resubmit;
999 	}
1000 free_urb:
1001 	skb_unlink(skb, &usb->tx.submitted_skbs);
1002 	zd_mac_tx_to_dev(skb, urb->status);
1003 	usb_free_urb(urb);
1004 	tx_dec_submitted_urbs(usb);
1005 	return;
1006 resubmit:
1007 	usb_anchor_urb(urb, &tx->submitted);
1008 	r = usb_submit_urb(urb, GFP_ATOMIC);
1009 	if (r) {
1010 		usb_unanchor_urb(urb);
1011 		dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
1012 		goto free_urb;
1013 	}
1014 }
1015 
1016 /**
1017  * zd_usb_tx: initiates transfer of a frame of the device
1018  *
1019  * @usb: the zd1211rw-private USB structure
1020  * @skb: a &struct sk_buff pointer
1021  *
1022  * This function tranmits a frame to the device. It doesn't wait for
1023  * completion. The frame must contain the control set and have all the
1024  * control set information available.
1025  *
1026  * The function returns 0 if the transfer has been successfully initiated.
1027  */
1028 int zd_usb_tx(struct zd_usb *usb, struct sk_buff *skb)
1029 {
1030 	int r;
1031 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1032 	struct usb_device *udev = zd_usb_to_usbdev(usb);
1033 	struct urb *urb;
1034 	struct zd_usb_tx *tx = &usb->tx;
1035 
1036 	if (!atomic_read(&tx->enabled)) {
1037 		r = -ENOENT;
1038 		goto out;
1039 	}
1040 
1041 	urb = usb_alloc_urb(0, GFP_ATOMIC);
1042 	if (!urb) {
1043 		r = -ENOMEM;
1044 		goto out;
1045 	}
1046 
1047 	usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
1048 		          skb->data, skb->len, tx_urb_complete, skb);
1049 
1050 	info->rate_driver_data[1] = (void *)jiffies;
1051 	skb_queue_tail(&tx->submitted_skbs, skb);
1052 	usb_anchor_urb(urb, &tx->submitted);
1053 
1054 	r = usb_submit_urb(urb, GFP_ATOMIC);
1055 	if (r) {
1056 		dev_dbg_f(zd_usb_dev(usb), "error submit urb %p %d\n", urb, r);
1057 		usb_unanchor_urb(urb);
1058 		skb_unlink(skb, &tx->submitted_skbs);
1059 		goto error;
1060 	}
1061 	tx_inc_submitted_urbs(usb);
1062 	return 0;
1063 error:
1064 	usb_free_urb(urb);
1065 out:
1066 	return r;
1067 }
1068 
1069 static bool zd_tx_timeout(struct zd_usb *usb)
1070 {
1071 	struct zd_usb_tx *tx = &usb->tx;
1072 	struct sk_buff_head *q = &tx->submitted_skbs;
1073 	struct sk_buff *skb, *skbnext;
1074 	struct ieee80211_tx_info *info;
1075 	unsigned long flags, trans_start;
1076 	bool have_timedout = false;
1077 
1078 	spin_lock_irqsave(&q->lock, flags);
1079 	skb_queue_walk_safe(q, skb, skbnext) {
1080 		info = IEEE80211_SKB_CB(skb);
1081 		trans_start = (unsigned long)info->rate_driver_data[1];
1082 
1083 		if (time_is_before_jiffies(trans_start + ZD_TX_TIMEOUT)) {
1084 			have_timedout = true;
1085 			break;
1086 		}
1087 	}
1088 	spin_unlock_irqrestore(&q->lock, flags);
1089 
1090 	return have_timedout;
1091 }
1092 
1093 static void zd_tx_watchdog_handler(struct work_struct *work)
1094 {
1095 	struct zd_usb *usb =
1096 		container_of(work, struct zd_usb, tx.watchdog_work.work);
1097 	struct zd_usb_tx *tx = &usb->tx;
1098 
1099 	if (!atomic_read(&tx->enabled) || !tx->watchdog_enabled)
1100 		goto out;
1101 	if (!zd_tx_timeout(usb))
1102 		goto out;
1103 
1104 	/* TX halted, try reset */
1105 	dev_warn(zd_usb_dev(usb), "TX-stall detected, resetting device...");
1106 
1107 	usb_queue_reset_device(usb->intf);
1108 
1109 	/* reset will stop this worker, don't rearm */
1110 	return;
1111 out:
1112 	queue_delayed_work(zd_workqueue, &tx->watchdog_work,
1113 			   ZD_TX_WATCHDOG_INTERVAL);
1114 }
1115 
1116 void zd_tx_watchdog_enable(struct zd_usb *usb)
1117 {
1118 	struct zd_usb_tx *tx = &usb->tx;
1119 
1120 	if (!tx->watchdog_enabled) {
1121 		dev_dbg_f(zd_usb_dev(usb), "\n");
1122 		queue_delayed_work(zd_workqueue, &tx->watchdog_work,
1123 				   ZD_TX_WATCHDOG_INTERVAL);
1124 		tx->watchdog_enabled = 1;
1125 	}
1126 }
1127 
1128 void zd_tx_watchdog_disable(struct zd_usb *usb)
1129 {
1130 	struct zd_usb_tx *tx = &usb->tx;
1131 
1132 	if (tx->watchdog_enabled) {
1133 		dev_dbg_f(zd_usb_dev(usb), "\n");
1134 		tx->watchdog_enabled = 0;
1135 		cancel_delayed_work_sync(&tx->watchdog_work);
1136 	}
1137 }
1138 
1139 static void zd_rx_idle_timer_handler(struct work_struct *work)
1140 {
1141 	struct zd_usb *usb =
1142 		container_of(work, struct zd_usb, rx.idle_work.work);
1143 	struct zd_mac *mac = zd_usb_to_mac(usb);
1144 
1145 	if (!test_bit(ZD_DEVICE_RUNNING, &mac->flags))
1146 		return;
1147 
1148 	dev_dbg_f(zd_usb_dev(usb), "\n");
1149 
1150 	/* 30 seconds since last rx, reset rx */
1151 	zd_usb_reset_rx(usb);
1152 }
1153 
1154 static void zd_usb_reset_rx_idle_timer_tasklet(unsigned long param)
1155 {
1156 	struct zd_usb *usb = (struct zd_usb *)param;
1157 
1158 	zd_usb_reset_rx_idle_timer(usb);
1159 }
1160 
1161 void zd_usb_reset_rx_idle_timer(struct zd_usb *usb)
1162 {
1163 	struct zd_usb_rx *rx = &usb->rx;
1164 
1165 	mod_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
1166 }
1167 
1168 static inline void init_usb_interrupt(struct zd_usb *usb)
1169 {
1170 	struct zd_usb_interrupt *intr = &usb->intr;
1171 
1172 	spin_lock_init(&intr->lock);
1173 	intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
1174 	init_completion(&intr->read_regs.completion);
1175 	atomic_set(&intr->read_regs_enabled, 0);
1176 	intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
1177 }
1178 
1179 static inline void init_usb_rx(struct zd_usb *usb)
1180 {
1181 	struct zd_usb_rx *rx = &usb->rx;
1182 
1183 	spin_lock_init(&rx->lock);
1184 	mutex_init(&rx->setup_mutex);
1185 	if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
1186 		rx->usb_packet_size = 512;
1187 	} else {
1188 		rx->usb_packet_size = 64;
1189 	}
1190 	ZD_ASSERT(rx->fragment_length == 0);
1191 	INIT_DELAYED_WORK(&rx->idle_work, zd_rx_idle_timer_handler);
1192 	rx->reset_timer_tasklet.func = zd_usb_reset_rx_idle_timer_tasklet;
1193 	rx->reset_timer_tasklet.data = (unsigned long)usb;
1194 }
1195 
1196 static inline void init_usb_tx(struct zd_usb *usb)
1197 {
1198 	struct zd_usb_tx *tx = &usb->tx;
1199 
1200 	spin_lock_init(&tx->lock);
1201 	atomic_set(&tx->enabled, 0);
1202 	tx->stopped = 0;
1203 	skb_queue_head_init(&tx->submitted_skbs);
1204 	init_usb_anchor(&tx->submitted);
1205 	tx->submitted_urbs = 0;
1206 	tx->watchdog_enabled = 0;
1207 	INIT_DELAYED_WORK(&tx->watchdog_work, zd_tx_watchdog_handler);
1208 }
1209 
1210 void zd_usb_init(struct zd_usb *usb, struct ieee80211_hw *hw,
1211 	         struct usb_interface *intf)
1212 {
1213 	memset(usb, 0, sizeof(*usb));
1214 	usb->intf = usb_get_intf(intf);
1215 	usb_set_intfdata(usb->intf, hw);
1216 	init_usb_anchor(&usb->submitted_cmds);
1217 	init_usb_interrupt(usb);
1218 	init_usb_tx(usb);
1219 	init_usb_rx(usb);
1220 }
1221 
1222 void zd_usb_clear(struct zd_usb *usb)
1223 {
1224 	usb_set_intfdata(usb->intf, NULL);
1225 	usb_put_intf(usb->intf);
1226 	ZD_MEMCLEAR(usb, sizeof(*usb));
1227 	/* FIXME: usb_interrupt, usb_tx, usb_rx? */
1228 }
1229 
1230 static const char *speed(enum usb_device_speed speed)
1231 {
1232 	switch (speed) {
1233 	case USB_SPEED_LOW:
1234 		return "low";
1235 	case USB_SPEED_FULL:
1236 		return "full";
1237 	case USB_SPEED_HIGH:
1238 		return "high";
1239 	default:
1240 		return "unknown speed";
1241 	}
1242 }
1243 
1244 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
1245 {
1246 	return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
1247 		le16_to_cpu(udev->descriptor.idVendor),
1248 		le16_to_cpu(udev->descriptor.idProduct),
1249 		get_bcdDevice(udev),
1250 		speed(udev->speed));
1251 }
1252 
1253 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
1254 {
1255 	struct usb_device *udev = interface_to_usbdev(usb->intf);
1256 	return scnprint_id(udev, buffer, size);
1257 }
1258 
1259 #ifdef DEBUG
1260 static void print_id(struct usb_device *udev)
1261 {
1262 	char buffer[40];
1263 
1264 	scnprint_id(udev, buffer, sizeof(buffer));
1265 	buffer[sizeof(buffer)-1] = 0;
1266 	dev_dbg_f(&udev->dev, "%s\n", buffer);
1267 }
1268 #else
1269 #define print_id(udev) do { } while (0)
1270 #endif
1271 
1272 static int eject_installer(struct usb_interface *intf)
1273 {
1274 	struct usb_device *udev = interface_to_usbdev(intf);
1275 	struct usb_host_interface *iface_desc = &intf->altsetting[0];
1276 	struct usb_endpoint_descriptor *endpoint;
1277 	unsigned char *cmd;
1278 	u8 bulk_out_ep;
1279 	int r;
1280 
1281 	/* Find bulk out endpoint */
1282 	for (r = 1; r >= 0; r--) {
1283 		endpoint = &iface_desc->endpoint[r].desc;
1284 		if (usb_endpoint_dir_out(endpoint) &&
1285 		    usb_endpoint_xfer_bulk(endpoint)) {
1286 			bulk_out_ep = endpoint->bEndpointAddress;
1287 			break;
1288 		}
1289 	}
1290 	if (r == -1) {
1291 		dev_err(&udev->dev,
1292 			"zd1211rw: Could not find bulk out endpoint\n");
1293 		return -ENODEV;
1294 	}
1295 
1296 	cmd = kzalloc(31, GFP_KERNEL);
1297 	if (cmd == NULL)
1298 		return -ENODEV;
1299 
1300 	/* USB bulk command block */
1301 	cmd[0] = 0x55;	/* bulk command signature */
1302 	cmd[1] = 0x53;	/* bulk command signature */
1303 	cmd[2] = 0x42;	/* bulk command signature */
1304 	cmd[3] = 0x43;	/* bulk command signature */
1305 	cmd[14] = 6;	/* command length */
1306 
1307 	cmd[15] = 0x1b;	/* SCSI command: START STOP UNIT */
1308 	cmd[19] = 0x2;	/* eject disc */
1309 
1310 	dev_info(&udev->dev, "Ejecting virtual installer media...\n");
1311 	r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
1312 		cmd, 31, NULL, 2000);
1313 	kfree(cmd);
1314 	if (r)
1315 		return r;
1316 
1317 	/* At this point, the device disconnects and reconnects with the real
1318 	 * ID numbers. */
1319 
1320 	usb_set_intfdata(intf, NULL);
1321 	return 0;
1322 }
1323 
1324 int zd_usb_init_hw(struct zd_usb *usb)
1325 {
1326 	int r;
1327 	struct zd_mac *mac = zd_usb_to_mac(usb);
1328 
1329 	dev_dbg_f(zd_usb_dev(usb), "\n");
1330 
1331 	r = upload_firmware(usb);
1332 	if (r) {
1333 		dev_err(zd_usb_dev(usb),
1334 		       "couldn't load firmware. Error number %d\n", r);
1335 		return r;
1336 	}
1337 
1338 	r = usb_reset_configuration(zd_usb_to_usbdev(usb));
1339 	if (r) {
1340 		dev_dbg_f(zd_usb_dev(usb),
1341 			"couldn't reset configuration. Error number %d\n", r);
1342 		return r;
1343 	}
1344 
1345 	r = zd_mac_init_hw(mac->hw);
1346 	if (r) {
1347 		dev_dbg_f(zd_usb_dev(usb),
1348 		         "couldn't initialize mac. Error number %d\n", r);
1349 		return r;
1350 	}
1351 
1352 	usb->initialized = 1;
1353 	return 0;
1354 }
1355 
1356 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
1357 {
1358 	int r;
1359 	struct usb_device *udev = interface_to_usbdev(intf);
1360 	struct zd_usb *usb;
1361 	struct ieee80211_hw *hw = NULL;
1362 
1363 	print_id(udev);
1364 
1365 	if (id->driver_info & DEVICE_INSTALLER)
1366 		return eject_installer(intf);
1367 
1368 	switch (udev->speed) {
1369 	case USB_SPEED_LOW:
1370 	case USB_SPEED_FULL:
1371 	case USB_SPEED_HIGH:
1372 		break;
1373 	default:
1374 		dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1375 		r = -ENODEV;
1376 		goto error;
1377 	}
1378 
1379 	r = usb_reset_device(udev);
1380 	if (r) {
1381 		dev_err(&intf->dev,
1382 			"couldn't reset usb device. Error number %d\n", r);
1383 		goto error;
1384 	}
1385 
1386 	hw = zd_mac_alloc_hw(intf);
1387 	if (hw == NULL) {
1388 		r = -ENOMEM;
1389 		goto error;
1390 	}
1391 
1392 	usb = &zd_hw_mac(hw)->chip.usb;
1393 	usb->is_zd1211b = (id->driver_info == DEVICE_ZD1211B) != 0;
1394 
1395 	r = zd_mac_preinit_hw(hw);
1396 	if (r) {
1397 		dev_dbg_f(&intf->dev,
1398 		         "couldn't initialize mac. Error number %d\n", r);
1399 		goto error;
1400 	}
1401 
1402 	r = ieee80211_register_hw(hw);
1403 	if (r) {
1404 		dev_dbg_f(&intf->dev,
1405 			 "couldn't register device. Error number %d\n", r);
1406 		goto error;
1407 	}
1408 
1409 	dev_dbg_f(&intf->dev, "successful\n");
1410 	dev_info(&intf->dev, "%s\n", wiphy_name(hw->wiphy));
1411 	return 0;
1412 error:
1413 	usb_reset_device(interface_to_usbdev(intf));
1414 	if (hw) {
1415 		zd_mac_clear(zd_hw_mac(hw));
1416 		ieee80211_free_hw(hw);
1417 	}
1418 	return r;
1419 }
1420 
1421 static void disconnect(struct usb_interface *intf)
1422 {
1423 	struct ieee80211_hw *hw = zd_intf_to_hw(intf);
1424 	struct zd_mac *mac;
1425 	struct zd_usb *usb;
1426 
1427 	/* Either something really bad happened, or we're just dealing with
1428 	 * a DEVICE_INSTALLER. */
1429 	if (hw == NULL)
1430 		return;
1431 
1432 	mac = zd_hw_mac(hw);
1433 	usb = &mac->chip.usb;
1434 
1435 	dev_dbg_f(zd_usb_dev(usb), "\n");
1436 
1437 	ieee80211_unregister_hw(hw);
1438 
1439 	/* Just in case something has gone wrong! */
1440 	zd_usb_disable_tx(usb);
1441 	zd_usb_disable_rx(usb);
1442 	zd_usb_disable_int(usb);
1443 
1444 	/* If the disconnect has been caused by a removal of the
1445 	 * driver module, the reset allows reloading of the driver. If the
1446 	 * reset will not be executed here, the upload of the firmware in the
1447 	 * probe function caused by the reloading of the driver will fail.
1448 	 */
1449 	usb_reset_device(interface_to_usbdev(intf));
1450 
1451 	zd_mac_clear(mac);
1452 	ieee80211_free_hw(hw);
1453 	dev_dbg(&intf->dev, "disconnected\n");
1454 }
1455 
1456 static void zd_usb_resume(struct zd_usb *usb)
1457 {
1458 	struct zd_mac *mac = zd_usb_to_mac(usb);
1459 	int r;
1460 
1461 	dev_dbg_f(zd_usb_dev(usb), "\n");
1462 
1463 	r = zd_op_start(zd_usb_to_hw(usb));
1464 	if (r < 0) {
1465 		dev_warn(zd_usb_dev(usb), "Device resume failed "
1466 			 "with error code %d. Retrying...\n", r);
1467 		if (usb->was_running)
1468 			set_bit(ZD_DEVICE_RUNNING, &mac->flags);
1469 		usb_queue_reset_device(usb->intf);
1470 		return;
1471 	}
1472 
1473 	if (mac->type != NL80211_IFTYPE_UNSPECIFIED) {
1474 		r = zd_restore_settings(mac);
1475 		if (r < 0) {
1476 			dev_dbg(zd_usb_dev(usb),
1477 				"failed to restore settings, %d\n", r);
1478 			return;
1479 		}
1480 	}
1481 }
1482 
1483 static void zd_usb_stop(struct zd_usb *usb)
1484 {
1485 	dev_dbg_f(zd_usb_dev(usb), "\n");
1486 
1487 	zd_op_stop(zd_usb_to_hw(usb));
1488 
1489 	zd_usb_disable_tx(usb);
1490 	zd_usb_disable_rx(usb);
1491 	zd_usb_disable_int(usb);
1492 
1493 	usb->initialized = 0;
1494 }
1495 
1496 static int pre_reset(struct usb_interface *intf)
1497 {
1498 	struct ieee80211_hw *hw = usb_get_intfdata(intf);
1499 	struct zd_mac *mac;
1500 	struct zd_usb *usb;
1501 
1502 	if (!hw || intf->condition != USB_INTERFACE_BOUND)
1503 		return 0;
1504 
1505 	mac = zd_hw_mac(hw);
1506 	usb = &mac->chip.usb;
1507 
1508 	usb->was_running = test_bit(ZD_DEVICE_RUNNING, &mac->flags);
1509 
1510 	zd_usb_stop(usb);
1511 
1512 	mutex_lock(&mac->chip.mutex);
1513 	return 0;
1514 }
1515 
1516 static int post_reset(struct usb_interface *intf)
1517 {
1518 	struct ieee80211_hw *hw = usb_get_intfdata(intf);
1519 	struct zd_mac *mac;
1520 	struct zd_usb *usb;
1521 
1522 	if (!hw || intf->condition != USB_INTERFACE_BOUND)
1523 		return 0;
1524 
1525 	mac = zd_hw_mac(hw);
1526 	usb = &mac->chip.usb;
1527 
1528 	mutex_unlock(&mac->chip.mutex);
1529 
1530 	if (usb->was_running)
1531 		zd_usb_resume(usb);
1532 	return 0;
1533 }
1534 
1535 static struct usb_driver driver = {
1536 	.name		= KBUILD_MODNAME,
1537 	.id_table	= usb_ids,
1538 	.probe		= probe,
1539 	.disconnect	= disconnect,
1540 	.pre_reset	= pre_reset,
1541 	.post_reset	= post_reset,
1542 	.disable_hub_initiated_lpm = 1,
1543 };
1544 
1545 struct workqueue_struct *zd_workqueue;
1546 
1547 static int __init usb_init(void)
1548 {
1549 	int r;
1550 
1551 	pr_debug("%s usb_init()\n", driver.name);
1552 
1553 	zd_workqueue = create_singlethread_workqueue(driver.name);
1554 	if (zd_workqueue == NULL) {
1555 		printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1556 		return -ENOMEM;
1557 	}
1558 
1559 	r = usb_register(&driver);
1560 	if (r) {
1561 		destroy_workqueue(zd_workqueue);
1562 		printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1563 		       driver.name, r);
1564 		return r;
1565 	}
1566 
1567 	pr_debug("%s initialized\n", driver.name);
1568 	return 0;
1569 }
1570 
1571 static void __exit usb_exit(void)
1572 {
1573 	pr_debug("%s usb_exit()\n", driver.name);
1574 	usb_deregister(&driver);
1575 	destroy_workqueue(zd_workqueue);
1576 }
1577 
1578 module_init(usb_init);
1579 module_exit(usb_exit);
1580 
1581 static int zd_ep_regs_out_msg(struct usb_device *udev, void *data, int len,
1582 			      int *actual_length, int timeout)
1583 {
1584 	/* In USB 2.0 mode EP_REGS_OUT endpoint is interrupt type. However in
1585 	 * USB 1.1 mode endpoint is bulk. Select correct type URB by endpoint
1586 	 * descriptor.
1587 	 */
1588 	struct usb_host_endpoint *ep;
1589 	unsigned int pipe;
1590 
1591 	pipe = usb_sndintpipe(udev, EP_REGS_OUT);
1592 	ep = usb_pipe_endpoint(udev, pipe);
1593 	if (!ep)
1594 		return -EINVAL;
1595 
1596 	if (usb_endpoint_xfer_int(&ep->desc)) {
1597 		return usb_interrupt_msg(udev, pipe, data, len,
1598 					 actual_length, timeout);
1599 	} else {
1600 		pipe = usb_sndbulkpipe(udev, EP_REGS_OUT);
1601 		return usb_bulk_msg(udev, pipe, data, len, actual_length,
1602 				    timeout);
1603 	}
1604 }
1605 
1606 static int usb_int_regs_length(unsigned int count)
1607 {
1608 	return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1609 }
1610 
1611 static void prepare_read_regs_int(struct zd_usb *usb,
1612 				  struct usb_req_read_regs *req,
1613 				  unsigned int count)
1614 {
1615 	struct zd_usb_interrupt *intr = &usb->intr;
1616 
1617 	spin_lock_irq(&intr->lock);
1618 	atomic_set(&intr->read_regs_enabled, 1);
1619 	intr->read_regs.req = req;
1620 	intr->read_regs.req_count = count;
1621 	reinit_completion(&intr->read_regs.completion);
1622 	spin_unlock_irq(&intr->lock);
1623 }
1624 
1625 static void disable_read_regs_int(struct zd_usb *usb)
1626 {
1627 	struct zd_usb_interrupt *intr = &usb->intr;
1628 
1629 	spin_lock_irq(&intr->lock);
1630 	atomic_set(&intr->read_regs_enabled, 0);
1631 	spin_unlock_irq(&intr->lock);
1632 }
1633 
1634 static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req,
1635 			    unsigned int count)
1636 {
1637 	int i;
1638 	struct zd_usb_interrupt *intr = &usb->intr;
1639 	struct read_regs_int *rr = &intr->read_regs;
1640 	struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1641 
1642 	/* The created block size seems to be larger than expected.
1643 	 * However results appear to be correct.
1644 	 */
1645 	if (rr->length < usb_int_regs_length(count)) {
1646 		dev_dbg_f(zd_usb_dev(usb),
1647 			 "error: actual length %d less than expected %d\n",
1648 			 rr->length, usb_int_regs_length(count));
1649 		return false;
1650 	}
1651 
1652 	if (rr->length > sizeof(rr->buffer)) {
1653 		dev_dbg_f(zd_usb_dev(usb),
1654 			 "error: actual length %d exceeds buffer size %zu\n",
1655 			 rr->length, sizeof(rr->buffer));
1656 		return false;
1657 	}
1658 
1659 	for (i = 0; i < count; i++) {
1660 		struct reg_data *rd = &regs->regs[i];
1661 		if (rd->addr != req->addr[i]) {
1662 			dev_dbg_f(zd_usb_dev(usb),
1663 				 "rd[%d] addr %#06hx expected %#06hx\n", i,
1664 				 le16_to_cpu(rd->addr),
1665 				 le16_to_cpu(req->addr[i]));
1666 			return false;
1667 		}
1668 	}
1669 
1670 	return true;
1671 }
1672 
1673 static int get_results(struct zd_usb *usb, u16 *values,
1674 		       struct usb_req_read_regs *req, unsigned int count,
1675 		       bool *retry)
1676 {
1677 	int r;
1678 	int i;
1679 	struct zd_usb_interrupt *intr = &usb->intr;
1680 	struct read_regs_int *rr = &intr->read_regs;
1681 	struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1682 
1683 	spin_lock_irq(&intr->lock);
1684 
1685 	r = -EIO;
1686 
1687 	/* Read failed because firmware bug? */
1688 	*retry = !!intr->read_regs_int_overridden;
1689 	if (*retry)
1690 		goto error_unlock;
1691 
1692 	if (!check_read_regs(usb, req, count)) {
1693 		dev_dbg_f(zd_usb_dev(usb), "error: invalid read regs\n");
1694 		goto error_unlock;
1695 	}
1696 
1697 	for (i = 0; i < count; i++) {
1698 		struct reg_data *rd = &regs->regs[i];
1699 		values[i] = le16_to_cpu(rd->value);
1700 	}
1701 
1702 	r = 0;
1703 error_unlock:
1704 	spin_unlock_irq(&intr->lock);
1705 	return r;
1706 }
1707 
1708 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1709 	             const zd_addr_t *addresses, unsigned int count)
1710 {
1711 	int r, i, req_len, actual_req_len, try_count = 0;
1712 	struct usb_device *udev;
1713 	struct usb_req_read_regs *req = NULL;
1714 	unsigned long timeout;
1715 	bool retry = false;
1716 
1717 	if (count < 1) {
1718 		dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1719 		return -EINVAL;
1720 	}
1721 	if (count > USB_MAX_IOREAD16_COUNT) {
1722 		dev_dbg_f(zd_usb_dev(usb),
1723 			 "error: count %u exceeds possible max %u\n",
1724 			 count, USB_MAX_IOREAD16_COUNT);
1725 		return -EINVAL;
1726 	}
1727 	if (in_atomic()) {
1728 		dev_dbg_f(zd_usb_dev(usb),
1729 			 "error: io in atomic context not supported\n");
1730 		return -EWOULDBLOCK;
1731 	}
1732 	if (!usb_int_enabled(usb)) {
1733 		dev_dbg_f(zd_usb_dev(usb),
1734 			  "error: usb interrupt not enabled\n");
1735 		return -EWOULDBLOCK;
1736 	}
1737 
1738 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1739 	BUILD_BUG_ON(sizeof(struct usb_req_read_regs) + USB_MAX_IOREAD16_COUNT *
1740 		     sizeof(__le16) > sizeof(usb->req_buf));
1741 	BUG_ON(sizeof(struct usb_req_read_regs) + count * sizeof(__le16) >
1742 	       sizeof(usb->req_buf));
1743 
1744 	req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1745 	req = (void *)usb->req_buf;
1746 
1747 	req->id = cpu_to_le16(USB_REQ_READ_REGS);
1748 	for (i = 0; i < count; i++)
1749 		req->addr[i] = cpu_to_le16((u16)addresses[i]);
1750 
1751 retry_read:
1752 	try_count++;
1753 	udev = zd_usb_to_usbdev(usb);
1754 	prepare_read_regs_int(usb, req, count);
1755 	r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/);
1756 	if (r) {
1757 		dev_dbg_f(zd_usb_dev(usb),
1758 			"error in zd_ep_regs_out_msg(). Error number %d\n", r);
1759 		goto error;
1760 	}
1761 	if (req_len != actual_req_len) {
1762 		dev_dbg_f(zd_usb_dev(usb), "error in zd_ep_regs_out_msg()\n"
1763 			" req_len %d != actual_req_len %d\n",
1764 			req_len, actual_req_len);
1765 		r = -EIO;
1766 		goto error;
1767 	}
1768 
1769 	timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1770 					      msecs_to_jiffies(50));
1771 	if (!timeout) {
1772 		disable_read_regs_int(usb);
1773 		dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1774 		r = -ETIMEDOUT;
1775 		goto error;
1776 	}
1777 
1778 	r = get_results(usb, values, req, count, &retry);
1779 	if (retry && try_count < 20) {
1780 		dev_dbg_f(zd_usb_dev(usb), "read retry, tries so far: %d\n",
1781 				try_count);
1782 		goto retry_read;
1783 	}
1784 error:
1785 	return r;
1786 }
1787 
1788 static void iowrite16v_urb_complete(struct urb *urb)
1789 {
1790 	struct zd_usb *usb = urb->context;
1791 
1792 	if (urb->status && !usb->cmd_error)
1793 		usb->cmd_error = urb->status;
1794 
1795 	if (!usb->cmd_error &&
1796 			urb->actual_length != urb->transfer_buffer_length)
1797 		usb->cmd_error = -EIO;
1798 }
1799 
1800 static int zd_submit_waiting_urb(struct zd_usb *usb, bool last)
1801 {
1802 	int r = 0;
1803 	struct urb *urb = usb->urb_async_waiting;
1804 
1805 	if (!urb)
1806 		return 0;
1807 
1808 	usb->urb_async_waiting = NULL;
1809 
1810 	if (!last)
1811 		urb->transfer_flags |= URB_NO_INTERRUPT;
1812 
1813 	usb_anchor_urb(urb, &usb->submitted_cmds);
1814 	r = usb_submit_urb(urb, GFP_KERNEL);
1815 	if (r) {
1816 		usb_unanchor_urb(urb);
1817 		dev_dbg_f(zd_usb_dev(usb),
1818 			"error in usb_submit_urb(). Error number %d\n", r);
1819 		goto error;
1820 	}
1821 
1822 	/* fall-through with r == 0 */
1823 error:
1824 	usb_free_urb(urb);
1825 	return r;
1826 }
1827 
1828 void zd_usb_iowrite16v_async_start(struct zd_usb *usb)
1829 {
1830 	ZD_ASSERT(usb_anchor_empty(&usb->submitted_cmds));
1831 	ZD_ASSERT(usb->urb_async_waiting == NULL);
1832 	ZD_ASSERT(!usb->in_async);
1833 
1834 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1835 
1836 	usb->in_async = 1;
1837 	usb->cmd_error = 0;
1838 	usb->urb_async_waiting = NULL;
1839 }
1840 
1841 int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout)
1842 {
1843 	int r;
1844 
1845 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1846 	ZD_ASSERT(usb->in_async);
1847 
1848 	/* Submit last iowrite16v URB */
1849 	r = zd_submit_waiting_urb(usb, true);
1850 	if (r) {
1851 		dev_dbg_f(zd_usb_dev(usb),
1852 			"error in zd_submit_waiting_usb(). "
1853 			"Error number %d\n", r);
1854 
1855 		usb_kill_anchored_urbs(&usb->submitted_cmds);
1856 		goto error;
1857 	}
1858 
1859 	if (timeout)
1860 		timeout = usb_wait_anchor_empty_timeout(&usb->submitted_cmds,
1861 							timeout);
1862 	if (!timeout) {
1863 		usb_kill_anchored_urbs(&usb->submitted_cmds);
1864 		if (usb->cmd_error == -ENOENT) {
1865 			dev_dbg_f(zd_usb_dev(usb), "timed out");
1866 			r = -ETIMEDOUT;
1867 			goto error;
1868 		}
1869 	}
1870 
1871 	r = usb->cmd_error;
1872 error:
1873 	usb->in_async = 0;
1874 	return r;
1875 }
1876 
1877 int zd_usb_iowrite16v_async(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1878 			    unsigned int count)
1879 {
1880 	int r;
1881 	struct usb_device *udev;
1882 	struct usb_req_write_regs *req = NULL;
1883 	int i, req_len;
1884 	struct urb *urb;
1885 	struct usb_host_endpoint *ep;
1886 
1887 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1888 	ZD_ASSERT(usb->in_async);
1889 
1890 	if (count == 0)
1891 		return 0;
1892 	if (count > USB_MAX_IOWRITE16_COUNT) {
1893 		dev_dbg_f(zd_usb_dev(usb),
1894 			"error: count %u exceeds possible max %u\n",
1895 			count, USB_MAX_IOWRITE16_COUNT);
1896 		return -EINVAL;
1897 	}
1898 	if (in_atomic()) {
1899 		dev_dbg_f(zd_usb_dev(usb),
1900 			"error: io in atomic context not supported\n");
1901 		return -EWOULDBLOCK;
1902 	}
1903 
1904 	udev = zd_usb_to_usbdev(usb);
1905 
1906 	ep = usb_pipe_endpoint(udev, usb_sndintpipe(udev, EP_REGS_OUT));
1907 	if (!ep)
1908 		return -ENOENT;
1909 
1910 	urb = usb_alloc_urb(0, GFP_KERNEL);
1911 	if (!urb)
1912 		return -ENOMEM;
1913 
1914 	req_len = sizeof(struct usb_req_write_regs) +
1915 		  count * sizeof(struct reg_data);
1916 	req = kmalloc(req_len, GFP_KERNEL);
1917 	if (!req) {
1918 		r = -ENOMEM;
1919 		goto error;
1920 	}
1921 
1922 	req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1923 	for (i = 0; i < count; i++) {
1924 		struct reg_data *rw  = &req->reg_writes[i];
1925 		rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1926 		rw->value = cpu_to_le16(ioreqs[i].value);
1927 	}
1928 
1929 	/* In USB 2.0 mode endpoint is interrupt type. However in USB 1.1 mode
1930 	 * endpoint is bulk. Select correct type URB by endpoint descriptor.
1931 	 */
1932 	if (usb_endpoint_xfer_int(&ep->desc))
1933 		usb_fill_int_urb(urb, udev, usb_sndintpipe(udev, EP_REGS_OUT),
1934 				 req, req_len, iowrite16v_urb_complete, usb,
1935 				 ep->desc.bInterval);
1936 	else
1937 		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1938 				  req, req_len, iowrite16v_urb_complete, usb);
1939 
1940 	urb->transfer_flags |= URB_FREE_BUFFER;
1941 
1942 	/* Submit previous URB */
1943 	r = zd_submit_waiting_urb(usb, false);
1944 	if (r) {
1945 		dev_dbg_f(zd_usb_dev(usb),
1946 			"error in zd_submit_waiting_usb(). "
1947 			"Error number %d\n", r);
1948 		goto error;
1949 	}
1950 
1951 	/* Delay submit so that URB_NO_INTERRUPT flag can be set for all URBs
1952 	 * of currect batch except for very last.
1953 	 */
1954 	usb->urb_async_waiting = urb;
1955 	return 0;
1956 error:
1957 	usb_free_urb(urb);
1958 	return r;
1959 }
1960 
1961 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1962 			unsigned int count)
1963 {
1964 	int r;
1965 
1966 	zd_usb_iowrite16v_async_start(usb);
1967 	r = zd_usb_iowrite16v_async(usb, ioreqs, count);
1968 	if (r) {
1969 		zd_usb_iowrite16v_async_end(usb, 0);
1970 		return r;
1971 	}
1972 	return zd_usb_iowrite16v_async_end(usb, 50 /* ms */);
1973 }
1974 
1975 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1976 {
1977 	int r;
1978 	struct usb_device *udev;
1979 	struct usb_req_rfwrite *req = NULL;
1980 	int i, req_len, actual_req_len;
1981 	u16 bit_value_template;
1982 
1983 	if (in_atomic()) {
1984 		dev_dbg_f(zd_usb_dev(usb),
1985 			"error: io in atomic context not supported\n");
1986 		return -EWOULDBLOCK;
1987 	}
1988 	if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1989 		dev_dbg_f(zd_usb_dev(usb),
1990 			"error: bits %d are smaller than"
1991 			" USB_MIN_RFWRITE_BIT_COUNT %d\n",
1992 			bits, USB_MIN_RFWRITE_BIT_COUNT);
1993 		return -EINVAL;
1994 	}
1995 	if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1996 		dev_dbg_f(zd_usb_dev(usb),
1997 			"error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1998 			bits, USB_MAX_RFWRITE_BIT_COUNT);
1999 		return -EINVAL;
2000 	}
2001 #ifdef DEBUG
2002 	if (value & (~0UL << bits)) {
2003 		dev_dbg_f(zd_usb_dev(usb),
2004 			"error: value %#09x has bits >= %d set\n",
2005 			value, bits);
2006 		return -EINVAL;
2007 	}
2008 #endif /* DEBUG */
2009 
2010 	dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
2011 
2012 	r = zd_usb_ioread16(usb, &bit_value_template, ZD_CR203);
2013 	if (r) {
2014 		dev_dbg_f(zd_usb_dev(usb),
2015 			"error %d: Couldn't read ZD_CR203\n", r);
2016 		return r;
2017 	}
2018 	bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
2019 
2020 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
2021 	BUILD_BUG_ON(sizeof(struct usb_req_rfwrite) +
2022 		     USB_MAX_RFWRITE_BIT_COUNT * sizeof(__le16) >
2023 		     sizeof(usb->req_buf));
2024 	BUG_ON(sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16) >
2025 	       sizeof(usb->req_buf));
2026 
2027 	req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
2028 	req = (void *)usb->req_buf;
2029 
2030 	req->id = cpu_to_le16(USB_REQ_WRITE_RF);
2031 	/* 1: 3683a, but not used in ZYDAS driver */
2032 	req->value = cpu_to_le16(2);
2033 	req->bits = cpu_to_le16(bits);
2034 
2035 	for (i = 0; i < bits; i++) {
2036 		u16 bv = bit_value_template;
2037 		if (value & (1 << (bits-1-i)))
2038 			bv |= RF_DATA;
2039 		req->bit_values[i] = cpu_to_le16(bv);
2040 	}
2041 
2042 	udev = zd_usb_to_usbdev(usb);
2043 	r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/);
2044 	if (r) {
2045 		dev_dbg_f(zd_usb_dev(usb),
2046 			"error in zd_ep_regs_out_msg(). Error number %d\n", r);
2047 		goto out;
2048 	}
2049 	if (req_len != actual_req_len) {
2050 		dev_dbg_f(zd_usb_dev(usb), "error in zd_ep_regs_out_msg()"
2051 			" req_len %d != actual_req_len %d\n",
2052 			req_len, actual_req_len);
2053 		r = -EIO;
2054 		goto out;
2055 	}
2056 
2057 	/* FALL-THROUGH with r == 0 */
2058 out:
2059 	return r;
2060 }
2061