xref: /linux/drivers/net/wireless/zydas/zd1211rw/zd_usb.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
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 const 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 	unsigned long flags;
375 
376 	spin_lock_irqsave(&intr->lock, flags);
377 	if (atomic_read(&intr->read_regs_enabled)) {
378 		atomic_set(&intr->read_regs_enabled, 0);
379 		intr->read_regs_int_overridden = 1;
380 		complete(&intr->read_regs.completion);
381 	}
382 	spin_unlock_irqrestore(&intr->lock, flags);
383 }
384 
385 static inline void handle_regs_int(struct urb *urb)
386 {
387 	struct zd_usb *usb = urb->context;
388 	struct zd_usb_interrupt *intr = &usb->intr;
389 	unsigned long flags;
390 	int len;
391 	u16 int_num;
392 
393 	ZD_ASSERT(in_interrupt());
394 	spin_lock_irqsave(&intr->lock, flags);
395 
396 	int_num = le16_to_cpu(*(__le16 *)(urb->transfer_buffer+2));
397 	if (int_num == CR_INTERRUPT) {
398 		struct zd_mac *mac = zd_hw_mac(zd_usb_to_hw(urb->context));
399 		spin_lock(&mac->lock);
400 		memcpy(&mac->intr_buffer, urb->transfer_buffer,
401 				USB_MAX_EP_INT_BUFFER);
402 		spin_unlock(&mac->lock);
403 		schedule_work(&mac->process_intr);
404 	} else if (atomic_read(&intr->read_regs_enabled)) {
405 		len = urb->actual_length;
406 		intr->read_regs.length = urb->actual_length;
407 		if (len > sizeof(intr->read_regs.buffer))
408 			len = sizeof(intr->read_regs.buffer);
409 
410 		memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
411 
412 		/* Sometimes USB_INT_ID_REGS is not overridden, but comes after
413 		 * USB_INT_ID_RETRY_FAILED. Read-reg retry then gets this
414 		 * delayed USB_INT_ID_REGS, but leaves USB_INT_ID_REGS of
415 		 * retry unhandled. Next read-reg command then might catch
416 		 * this wrong USB_INT_ID_REGS. Fix by ignoring wrong reads.
417 		 */
418 		if (!check_read_regs(usb, intr->read_regs.req,
419 						intr->read_regs.req_count))
420 			goto out;
421 
422 		atomic_set(&intr->read_regs_enabled, 0);
423 		intr->read_regs_int_overridden = 0;
424 		complete(&intr->read_regs.completion);
425 
426 		goto out;
427 	}
428 
429 out:
430 	spin_unlock_irqrestore(&intr->lock, flags);
431 
432 	/* CR_INTERRUPT might override read_reg too. */
433 	if (int_num == CR_INTERRUPT && atomic_read(&intr->read_regs_enabled))
434 		handle_regs_int_override(urb);
435 }
436 
437 static void int_urb_complete(struct urb *urb)
438 {
439 	int r;
440 	struct usb_int_header *hdr;
441 	struct zd_usb *usb;
442 	struct zd_usb_interrupt *intr;
443 
444 	switch (urb->status) {
445 	case 0:
446 		break;
447 	case -ESHUTDOWN:
448 	case -EINVAL:
449 	case -ENODEV:
450 	case -ENOENT:
451 	case -ECONNRESET:
452 	case -EPIPE:
453 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
454 		return;
455 	default:
456 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
457 		goto resubmit;
458 	}
459 
460 	if (urb->actual_length < sizeof(hdr)) {
461 		dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
462 		goto resubmit;
463 	}
464 
465 	hdr = urb->transfer_buffer;
466 	if (hdr->type != USB_INT_TYPE) {
467 		dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
468 		goto resubmit;
469 	}
470 
471 	/* USB_INT_ID_RETRY_FAILED triggered by tx-urb submit can override
472 	 * pending USB_INT_ID_REGS causing read command timeout.
473 	 */
474 	usb = urb->context;
475 	intr = &usb->intr;
476 	if (hdr->id != USB_INT_ID_REGS && atomic_read(&intr->read_regs_enabled))
477 		handle_regs_int_override(urb);
478 
479 	switch (hdr->id) {
480 	case USB_INT_ID_REGS:
481 		handle_regs_int(urb);
482 		break;
483 	case USB_INT_ID_RETRY_FAILED:
484 		zd_mac_tx_failed(urb);
485 		break;
486 	default:
487 		dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
488 			(unsigned int)hdr->id);
489 		goto resubmit;
490 	}
491 
492 resubmit:
493 	r = usb_submit_urb(urb, GFP_ATOMIC);
494 	if (r) {
495 		dev_dbg_f(urb_dev(urb), "error: resubmit urb %p err code %d\n",
496 			  urb, r);
497 		/* TODO: add worker to reset intr->urb */
498 	}
499 	return;
500 }
501 
502 static inline int int_urb_interval(struct usb_device *udev)
503 {
504 	switch (udev->speed) {
505 	case USB_SPEED_HIGH:
506 		return 4;
507 	case USB_SPEED_LOW:
508 		return 10;
509 	case USB_SPEED_FULL:
510 	default:
511 		return 1;
512 	}
513 }
514 
515 static inline int usb_int_enabled(struct zd_usb *usb)
516 {
517 	unsigned long flags;
518 	struct zd_usb_interrupt *intr = &usb->intr;
519 	struct urb *urb;
520 
521 	spin_lock_irqsave(&intr->lock, flags);
522 	urb = intr->urb;
523 	spin_unlock_irqrestore(&intr->lock, flags);
524 	return urb != NULL;
525 }
526 
527 int zd_usb_enable_int(struct zd_usb *usb)
528 {
529 	int r;
530 	struct usb_device *udev = zd_usb_to_usbdev(usb);
531 	struct zd_usb_interrupt *intr = &usb->intr;
532 	struct urb *urb;
533 
534 	dev_dbg_f(zd_usb_dev(usb), "\n");
535 
536 	urb = usb_alloc_urb(0, GFP_KERNEL);
537 	if (!urb) {
538 		r = -ENOMEM;
539 		goto out;
540 	}
541 
542 	ZD_ASSERT(!irqs_disabled());
543 	spin_lock_irq(&intr->lock);
544 	if (intr->urb) {
545 		spin_unlock_irq(&intr->lock);
546 		r = 0;
547 		goto error_free_urb;
548 	}
549 	intr->urb = urb;
550 	spin_unlock_irq(&intr->lock);
551 
552 	r = -ENOMEM;
553 	intr->buffer = usb_alloc_coherent(udev, USB_MAX_EP_INT_BUFFER,
554 					  GFP_KERNEL, &intr->buffer_dma);
555 	if (!intr->buffer) {
556 		dev_dbg_f(zd_usb_dev(usb),
557 			"couldn't allocate transfer_buffer\n");
558 		goto error_set_urb_null;
559 	}
560 
561 	usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
562 			 intr->buffer, USB_MAX_EP_INT_BUFFER,
563 			 int_urb_complete, usb,
564 			 intr->interval);
565 	urb->transfer_dma = intr->buffer_dma;
566 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
567 
568 	dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
569 	r = usb_submit_urb(urb, GFP_KERNEL);
570 	if (r) {
571 		dev_dbg_f(zd_usb_dev(usb),
572 			 "Couldn't submit urb. Error number %d\n", r);
573 		goto error;
574 	}
575 
576 	return 0;
577 error:
578 	usb_free_coherent(udev, USB_MAX_EP_INT_BUFFER,
579 			  intr->buffer, intr->buffer_dma);
580 error_set_urb_null:
581 	spin_lock_irq(&intr->lock);
582 	intr->urb = NULL;
583 	spin_unlock_irq(&intr->lock);
584 error_free_urb:
585 	usb_free_urb(urb);
586 out:
587 	return r;
588 }
589 
590 void zd_usb_disable_int(struct zd_usb *usb)
591 {
592 	unsigned long flags;
593 	struct usb_device *udev = zd_usb_to_usbdev(usb);
594 	struct zd_usb_interrupt *intr = &usb->intr;
595 	struct urb *urb;
596 	void *buffer;
597 	dma_addr_t buffer_dma;
598 
599 	spin_lock_irqsave(&intr->lock, flags);
600 	urb = intr->urb;
601 	if (!urb) {
602 		spin_unlock_irqrestore(&intr->lock, flags);
603 		return;
604 	}
605 	intr->urb = NULL;
606 	buffer = intr->buffer;
607 	buffer_dma = intr->buffer_dma;
608 	intr->buffer = NULL;
609 	spin_unlock_irqrestore(&intr->lock, flags);
610 
611 	usb_kill_urb(urb);
612 	dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
613 	usb_free_urb(urb);
614 
615 	if (buffer)
616 		usb_free_coherent(udev, USB_MAX_EP_INT_BUFFER,
617 				  buffer, buffer_dma);
618 }
619 
620 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
621 			     unsigned int length)
622 {
623 	int i;
624 	const struct rx_length_info *length_info;
625 
626 	if (length < sizeof(struct rx_length_info)) {
627 		/* It's not a complete packet anyhow. */
628 		dev_dbg_f(zd_usb_dev(usb), "invalid, small RX packet : %d\n",
629 					   length);
630 		return;
631 	}
632 	length_info = (struct rx_length_info *)
633 		(buffer + length - sizeof(struct rx_length_info));
634 
635 	/* It might be that three frames are merged into a single URB
636 	 * transaction. We have to check for the length info tag.
637 	 *
638 	 * While testing we discovered that length_info might be unaligned,
639 	 * because if USB transactions are merged, the last packet will not
640 	 * be padded. Unaligned access might also happen if the length_info
641 	 * structure is not present.
642 	 */
643 	if (get_unaligned_le16(&length_info->tag) == RX_LENGTH_INFO_TAG)
644 	{
645 		unsigned int l, k, n;
646 		for (i = 0, l = 0;; i++) {
647 			k = get_unaligned_le16(&length_info->length[i]);
648 			if (k == 0)
649 				return;
650 			n = l+k;
651 			if (n > length)
652 				return;
653 			zd_mac_rx(zd_usb_to_hw(usb), buffer+l, k);
654 			if (i >= 2)
655 				return;
656 			l = (n+3) & ~3;
657 		}
658 	} else {
659 		zd_mac_rx(zd_usb_to_hw(usb), buffer, length);
660 	}
661 }
662 
663 static void rx_urb_complete(struct urb *urb)
664 {
665 	int r;
666 	struct zd_usb *usb;
667 	struct zd_usb_rx *rx;
668 	const u8 *buffer;
669 	unsigned int length;
670 	unsigned long flags;
671 
672 	switch (urb->status) {
673 	case 0:
674 		break;
675 	case -ESHUTDOWN:
676 	case -EINVAL:
677 	case -ENODEV:
678 	case -ENOENT:
679 	case -ECONNRESET:
680 	case -EPIPE:
681 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
682 		return;
683 	default:
684 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
685 		goto resubmit;
686 	}
687 
688 	buffer = urb->transfer_buffer;
689 	length = urb->actual_length;
690 	usb = urb->context;
691 	rx = &usb->rx;
692 
693 	tasklet_schedule(&rx->reset_timer_tasklet);
694 
695 	if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
696 		/* If there is an old first fragment, we don't care. */
697 		dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
698 		ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
699 		spin_lock_irqsave(&rx->lock, flags);
700 		memcpy(rx->fragment, buffer, length);
701 		rx->fragment_length = length;
702 		spin_unlock_irqrestore(&rx->lock, flags);
703 		goto resubmit;
704 	}
705 
706 	spin_lock_irqsave(&rx->lock, flags);
707 	if (rx->fragment_length > 0) {
708 		/* We are on a second fragment, we believe */
709 		ZD_ASSERT(length + rx->fragment_length <=
710 			  ARRAY_SIZE(rx->fragment));
711 		dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
712 		memcpy(rx->fragment+rx->fragment_length, buffer, length);
713 		handle_rx_packet(usb, rx->fragment,
714 			         rx->fragment_length + length);
715 		rx->fragment_length = 0;
716 		spin_unlock_irqrestore(&rx->lock, flags);
717 	} else {
718 		spin_unlock_irqrestore(&rx->lock, flags);
719 		handle_rx_packet(usb, buffer, length);
720 	}
721 
722 resubmit:
723 	r = usb_submit_urb(urb, GFP_ATOMIC);
724 	if (r)
725 		dev_dbg_f(urb_dev(urb), "urb %p resubmit error %d\n", urb, r);
726 }
727 
728 static struct urb *alloc_rx_urb(struct zd_usb *usb)
729 {
730 	struct usb_device *udev = zd_usb_to_usbdev(usb);
731 	struct urb *urb;
732 	void *buffer;
733 
734 	urb = usb_alloc_urb(0, GFP_KERNEL);
735 	if (!urb)
736 		return NULL;
737 	buffer = usb_alloc_coherent(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
738 				    &urb->transfer_dma);
739 	if (!buffer) {
740 		usb_free_urb(urb);
741 		return NULL;
742 	}
743 
744 	usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
745 			  buffer, USB_MAX_RX_SIZE,
746 			  rx_urb_complete, usb);
747 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
748 
749 	return urb;
750 }
751 
752 static void free_rx_urb(struct urb *urb)
753 {
754 	if (!urb)
755 		return;
756 	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
757 			  urb->transfer_buffer, urb->transfer_dma);
758 	usb_free_urb(urb);
759 }
760 
761 static int __zd_usb_enable_rx(struct zd_usb *usb)
762 {
763 	int i, r;
764 	struct zd_usb_rx *rx = &usb->rx;
765 	struct urb **urbs;
766 
767 	dev_dbg_f(zd_usb_dev(usb), "\n");
768 
769 	r = -ENOMEM;
770 	urbs = kcalloc(RX_URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
771 	if (!urbs)
772 		goto error;
773 	for (i = 0; i < RX_URBS_COUNT; i++) {
774 		urbs[i] = alloc_rx_urb(usb);
775 		if (!urbs[i])
776 			goto error;
777 	}
778 
779 	ZD_ASSERT(!irqs_disabled());
780 	spin_lock_irq(&rx->lock);
781 	if (rx->urbs) {
782 		spin_unlock_irq(&rx->lock);
783 		r = 0;
784 		goto error;
785 	}
786 	rx->urbs = urbs;
787 	rx->urbs_count = RX_URBS_COUNT;
788 	spin_unlock_irq(&rx->lock);
789 
790 	for (i = 0; i < RX_URBS_COUNT; i++) {
791 		r = usb_submit_urb(urbs[i], GFP_KERNEL);
792 		if (r)
793 			goto error_submit;
794 	}
795 
796 	return 0;
797 error_submit:
798 	for (i = 0; i < RX_URBS_COUNT; i++) {
799 		usb_kill_urb(urbs[i]);
800 	}
801 	spin_lock_irq(&rx->lock);
802 	rx->urbs = NULL;
803 	rx->urbs_count = 0;
804 	spin_unlock_irq(&rx->lock);
805 error:
806 	if (urbs) {
807 		for (i = 0; i < RX_URBS_COUNT; i++)
808 			free_rx_urb(urbs[i]);
809 	}
810 	return r;
811 }
812 
813 int zd_usb_enable_rx(struct zd_usb *usb)
814 {
815 	int r;
816 	struct zd_usb_rx *rx = &usb->rx;
817 
818 	mutex_lock(&rx->setup_mutex);
819 	r = __zd_usb_enable_rx(usb);
820 	mutex_unlock(&rx->setup_mutex);
821 
822 	zd_usb_reset_rx_idle_timer(usb);
823 
824 	return r;
825 }
826 
827 static void __zd_usb_disable_rx(struct zd_usb *usb)
828 {
829 	int i;
830 	unsigned long flags;
831 	struct urb **urbs;
832 	unsigned int count;
833 	struct zd_usb_rx *rx = &usb->rx;
834 
835 	spin_lock_irqsave(&rx->lock, flags);
836 	urbs = rx->urbs;
837 	count = rx->urbs_count;
838 	spin_unlock_irqrestore(&rx->lock, flags);
839 	if (!urbs)
840 		return;
841 
842 	for (i = 0; i < count; i++) {
843 		usb_kill_urb(urbs[i]);
844 		free_rx_urb(urbs[i]);
845 	}
846 	kfree(urbs);
847 
848 	spin_lock_irqsave(&rx->lock, flags);
849 	rx->urbs = NULL;
850 	rx->urbs_count = 0;
851 	spin_unlock_irqrestore(&rx->lock, flags);
852 }
853 
854 void zd_usb_disable_rx(struct zd_usb *usb)
855 {
856 	struct zd_usb_rx *rx = &usb->rx;
857 
858 	mutex_lock(&rx->setup_mutex);
859 	__zd_usb_disable_rx(usb);
860 	mutex_unlock(&rx->setup_mutex);
861 
862 	tasklet_kill(&rx->reset_timer_tasklet);
863 	cancel_delayed_work_sync(&rx->idle_work);
864 }
865 
866 static void zd_usb_reset_rx(struct zd_usb *usb)
867 {
868 	bool do_reset;
869 	struct zd_usb_rx *rx = &usb->rx;
870 	unsigned long flags;
871 
872 	mutex_lock(&rx->setup_mutex);
873 
874 	spin_lock_irqsave(&rx->lock, flags);
875 	do_reset = rx->urbs != NULL;
876 	spin_unlock_irqrestore(&rx->lock, flags);
877 
878 	if (do_reset) {
879 		__zd_usb_disable_rx(usb);
880 		__zd_usb_enable_rx(usb);
881 	}
882 
883 	mutex_unlock(&rx->setup_mutex);
884 
885 	if (do_reset)
886 		zd_usb_reset_rx_idle_timer(usb);
887 }
888 
889 /**
890  * zd_usb_disable_tx - disable transmission
891  * @usb: the zd1211rw-private USB structure
892  *
893  * Frees all URBs in the free list and marks the transmission as disabled.
894  */
895 void zd_usb_disable_tx(struct zd_usb *usb)
896 {
897 	struct zd_usb_tx *tx = &usb->tx;
898 	unsigned long flags;
899 
900 	atomic_set(&tx->enabled, 0);
901 
902 	/* kill all submitted tx-urbs */
903 	usb_kill_anchored_urbs(&tx->submitted);
904 
905 	spin_lock_irqsave(&tx->lock, flags);
906 	WARN_ON(!skb_queue_empty(&tx->submitted_skbs));
907 	WARN_ON(tx->submitted_urbs != 0);
908 	tx->submitted_urbs = 0;
909 	spin_unlock_irqrestore(&tx->lock, flags);
910 
911 	/* The stopped state is ignored, relying on ieee80211_wake_queues()
912 	 * in a potentionally following zd_usb_enable_tx().
913 	 */
914 }
915 
916 /**
917  * zd_usb_enable_tx - enables transmission
918  * @usb: a &struct zd_usb pointer
919  *
920  * This function enables transmission and prepares the &zd_usb_tx data
921  * structure.
922  */
923 void zd_usb_enable_tx(struct zd_usb *usb)
924 {
925 	unsigned long flags;
926 	struct zd_usb_tx *tx = &usb->tx;
927 
928 	spin_lock_irqsave(&tx->lock, flags);
929 	atomic_set(&tx->enabled, 1);
930 	tx->submitted_urbs = 0;
931 	ieee80211_wake_queues(zd_usb_to_hw(usb));
932 	tx->stopped = 0;
933 	spin_unlock_irqrestore(&tx->lock, flags);
934 }
935 
936 static void tx_dec_submitted_urbs(struct zd_usb *usb)
937 {
938 	struct zd_usb_tx *tx = &usb->tx;
939 	unsigned long flags;
940 
941 	spin_lock_irqsave(&tx->lock, flags);
942 	--tx->submitted_urbs;
943 	if (tx->stopped && tx->submitted_urbs <= ZD_USB_TX_LOW) {
944 		ieee80211_wake_queues(zd_usb_to_hw(usb));
945 		tx->stopped = 0;
946 	}
947 	spin_unlock_irqrestore(&tx->lock, flags);
948 }
949 
950 static void tx_inc_submitted_urbs(struct zd_usb *usb)
951 {
952 	struct zd_usb_tx *tx = &usb->tx;
953 	unsigned long flags;
954 
955 	spin_lock_irqsave(&tx->lock, flags);
956 	++tx->submitted_urbs;
957 	if (!tx->stopped && tx->submitted_urbs > ZD_USB_TX_HIGH) {
958 		ieee80211_stop_queues(zd_usb_to_hw(usb));
959 		tx->stopped = 1;
960 	}
961 	spin_unlock_irqrestore(&tx->lock, flags);
962 }
963 
964 /**
965  * tx_urb_complete - completes the execution of an URB
966  * @urb: a URB
967  *
968  * This function is called if the URB has been transferred to a device or an
969  * error has happened.
970  */
971 static void tx_urb_complete(struct urb *urb)
972 {
973 	int r;
974 	struct sk_buff *skb;
975 	struct ieee80211_tx_info *info;
976 	struct zd_usb *usb;
977 	struct zd_usb_tx *tx;
978 
979 	skb = (struct sk_buff *)urb->context;
980 	info = IEEE80211_SKB_CB(skb);
981 	/*
982 	 * grab 'usb' pointer before handing off the skb (since
983 	 * it might be freed by zd_mac_tx_to_dev or mac80211)
984 	 */
985 	usb = &zd_hw_mac(info->rate_driver_data[0])->chip.usb;
986 	tx = &usb->tx;
987 
988 	switch (urb->status) {
989 	case 0:
990 		break;
991 	case -ESHUTDOWN:
992 	case -EINVAL:
993 	case -ENODEV:
994 	case -ENOENT:
995 	case -ECONNRESET:
996 	case -EPIPE:
997 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
998 		break;
999 	default:
1000 		dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
1001 		goto resubmit;
1002 	}
1003 free_urb:
1004 	skb_unlink(skb, &usb->tx.submitted_skbs);
1005 	zd_mac_tx_to_dev(skb, urb->status);
1006 	usb_free_urb(urb);
1007 	tx_dec_submitted_urbs(usb);
1008 	return;
1009 resubmit:
1010 	usb_anchor_urb(urb, &tx->submitted);
1011 	r = usb_submit_urb(urb, GFP_ATOMIC);
1012 	if (r) {
1013 		usb_unanchor_urb(urb);
1014 		dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
1015 		goto free_urb;
1016 	}
1017 }
1018 
1019 /**
1020  * zd_usb_tx: initiates transfer of a frame of the device
1021  *
1022  * @usb: the zd1211rw-private USB structure
1023  * @skb: a &struct sk_buff pointer
1024  *
1025  * This function tranmits a frame to the device. It doesn't wait for
1026  * completion. The frame must contain the control set and have all the
1027  * control set information available.
1028  *
1029  * The function returns 0 if the transfer has been successfully initiated.
1030  */
1031 int zd_usb_tx(struct zd_usb *usb, struct sk_buff *skb)
1032 {
1033 	int r;
1034 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1035 	struct usb_device *udev = zd_usb_to_usbdev(usb);
1036 	struct urb *urb;
1037 	struct zd_usb_tx *tx = &usb->tx;
1038 
1039 	if (!atomic_read(&tx->enabled)) {
1040 		r = -ENOENT;
1041 		goto out;
1042 	}
1043 
1044 	urb = usb_alloc_urb(0, GFP_ATOMIC);
1045 	if (!urb) {
1046 		r = -ENOMEM;
1047 		goto out;
1048 	}
1049 
1050 	usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
1051 		          skb->data, skb->len, tx_urb_complete, skb);
1052 
1053 	info->rate_driver_data[1] = (void *)jiffies;
1054 	skb_queue_tail(&tx->submitted_skbs, skb);
1055 	usb_anchor_urb(urb, &tx->submitted);
1056 
1057 	r = usb_submit_urb(urb, GFP_ATOMIC);
1058 	if (r) {
1059 		dev_dbg_f(zd_usb_dev(usb), "error submit urb %p %d\n", urb, r);
1060 		usb_unanchor_urb(urb);
1061 		skb_unlink(skb, &tx->submitted_skbs);
1062 		goto error;
1063 	}
1064 	tx_inc_submitted_urbs(usb);
1065 	return 0;
1066 error:
1067 	usb_free_urb(urb);
1068 out:
1069 	return r;
1070 }
1071 
1072 static bool zd_tx_timeout(struct zd_usb *usb)
1073 {
1074 	struct zd_usb_tx *tx = &usb->tx;
1075 	struct sk_buff_head *q = &tx->submitted_skbs;
1076 	struct sk_buff *skb, *skbnext;
1077 	struct ieee80211_tx_info *info;
1078 	unsigned long flags, trans_start;
1079 	bool have_timedout = false;
1080 
1081 	spin_lock_irqsave(&q->lock, flags);
1082 	skb_queue_walk_safe(q, skb, skbnext) {
1083 		info = IEEE80211_SKB_CB(skb);
1084 		trans_start = (unsigned long)info->rate_driver_data[1];
1085 
1086 		if (time_is_before_jiffies(trans_start + ZD_TX_TIMEOUT)) {
1087 			have_timedout = true;
1088 			break;
1089 		}
1090 	}
1091 	spin_unlock_irqrestore(&q->lock, flags);
1092 
1093 	return have_timedout;
1094 }
1095 
1096 static void zd_tx_watchdog_handler(struct work_struct *work)
1097 {
1098 	struct zd_usb *usb =
1099 		container_of(work, struct zd_usb, tx.watchdog_work.work);
1100 	struct zd_usb_tx *tx = &usb->tx;
1101 
1102 	if (!atomic_read(&tx->enabled) || !tx->watchdog_enabled)
1103 		goto out;
1104 	if (!zd_tx_timeout(usb))
1105 		goto out;
1106 
1107 	/* TX halted, try reset */
1108 	dev_warn(zd_usb_dev(usb), "TX-stall detected, resetting device...");
1109 
1110 	usb_queue_reset_device(usb->intf);
1111 
1112 	/* reset will stop this worker, don't rearm */
1113 	return;
1114 out:
1115 	queue_delayed_work(zd_workqueue, &tx->watchdog_work,
1116 			   ZD_TX_WATCHDOG_INTERVAL);
1117 }
1118 
1119 void zd_tx_watchdog_enable(struct zd_usb *usb)
1120 {
1121 	struct zd_usb_tx *tx = &usb->tx;
1122 
1123 	if (!tx->watchdog_enabled) {
1124 		dev_dbg_f(zd_usb_dev(usb), "\n");
1125 		queue_delayed_work(zd_workqueue, &tx->watchdog_work,
1126 				   ZD_TX_WATCHDOG_INTERVAL);
1127 		tx->watchdog_enabled = 1;
1128 	}
1129 }
1130 
1131 void zd_tx_watchdog_disable(struct zd_usb *usb)
1132 {
1133 	struct zd_usb_tx *tx = &usb->tx;
1134 
1135 	if (tx->watchdog_enabled) {
1136 		dev_dbg_f(zd_usb_dev(usb), "\n");
1137 		tx->watchdog_enabled = 0;
1138 		cancel_delayed_work_sync(&tx->watchdog_work);
1139 	}
1140 }
1141 
1142 static void zd_rx_idle_timer_handler(struct work_struct *work)
1143 {
1144 	struct zd_usb *usb =
1145 		container_of(work, struct zd_usb, rx.idle_work.work);
1146 	struct zd_mac *mac = zd_usb_to_mac(usb);
1147 
1148 	if (!test_bit(ZD_DEVICE_RUNNING, &mac->flags))
1149 		return;
1150 
1151 	dev_dbg_f(zd_usb_dev(usb), "\n");
1152 
1153 	/* 30 seconds since last rx, reset rx */
1154 	zd_usb_reset_rx(usb);
1155 }
1156 
1157 static void zd_usb_reset_rx_idle_timer_tasklet(unsigned long param)
1158 {
1159 	struct zd_usb *usb = (struct zd_usb *)param;
1160 
1161 	zd_usb_reset_rx_idle_timer(usb);
1162 }
1163 
1164 void zd_usb_reset_rx_idle_timer(struct zd_usb *usb)
1165 {
1166 	struct zd_usb_rx *rx = &usb->rx;
1167 
1168 	mod_delayed_work(zd_workqueue, &rx->idle_work, ZD_RX_IDLE_INTERVAL);
1169 }
1170 
1171 static inline void init_usb_interrupt(struct zd_usb *usb)
1172 {
1173 	struct zd_usb_interrupt *intr = &usb->intr;
1174 
1175 	spin_lock_init(&intr->lock);
1176 	intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
1177 	init_completion(&intr->read_regs.completion);
1178 	atomic_set(&intr->read_regs_enabled, 0);
1179 	intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
1180 }
1181 
1182 static inline void init_usb_rx(struct zd_usb *usb)
1183 {
1184 	struct zd_usb_rx *rx = &usb->rx;
1185 
1186 	spin_lock_init(&rx->lock);
1187 	mutex_init(&rx->setup_mutex);
1188 	if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
1189 		rx->usb_packet_size = 512;
1190 	} else {
1191 		rx->usb_packet_size = 64;
1192 	}
1193 	ZD_ASSERT(rx->fragment_length == 0);
1194 	INIT_DELAYED_WORK(&rx->idle_work, zd_rx_idle_timer_handler);
1195 	rx->reset_timer_tasklet.func = zd_usb_reset_rx_idle_timer_tasklet;
1196 	rx->reset_timer_tasklet.data = (unsigned long)usb;
1197 }
1198 
1199 static inline void init_usb_tx(struct zd_usb *usb)
1200 {
1201 	struct zd_usb_tx *tx = &usb->tx;
1202 
1203 	spin_lock_init(&tx->lock);
1204 	atomic_set(&tx->enabled, 0);
1205 	tx->stopped = 0;
1206 	skb_queue_head_init(&tx->submitted_skbs);
1207 	init_usb_anchor(&tx->submitted);
1208 	tx->submitted_urbs = 0;
1209 	tx->watchdog_enabled = 0;
1210 	INIT_DELAYED_WORK(&tx->watchdog_work, zd_tx_watchdog_handler);
1211 }
1212 
1213 void zd_usb_init(struct zd_usb *usb, struct ieee80211_hw *hw,
1214 	         struct usb_interface *intf)
1215 {
1216 	memset(usb, 0, sizeof(*usb));
1217 	usb->intf = usb_get_intf(intf);
1218 	usb_set_intfdata(usb->intf, hw);
1219 	init_usb_anchor(&usb->submitted_cmds);
1220 	init_usb_interrupt(usb);
1221 	init_usb_tx(usb);
1222 	init_usb_rx(usb);
1223 }
1224 
1225 void zd_usb_clear(struct zd_usb *usb)
1226 {
1227 	usb_set_intfdata(usb->intf, NULL);
1228 	usb_put_intf(usb->intf);
1229 	ZD_MEMCLEAR(usb, sizeof(*usb));
1230 	/* FIXME: usb_interrupt, usb_tx, usb_rx? */
1231 }
1232 
1233 static const char *speed(enum usb_device_speed speed)
1234 {
1235 	switch (speed) {
1236 	case USB_SPEED_LOW:
1237 		return "low";
1238 	case USB_SPEED_FULL:
1239 		return "full";
1240 	case USB_SPEED_HIGH:
1241 		return "high";
1242 	default:
1243 		return "unknown speed";
1244 	}
1245 }
1246 
1247 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
1248 {
1249 	return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
1250 		le16_to_cpu(udev->descriptor.idVendor),
1251 		le16_to_cpu(udev->descriptor.idProduct),
1252 		get_bcdDevice(udev),
1253 		speed(udev->speed));
1254 }
1255 
1256 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
1257 {
1258 	struct usb_device *udev = interface_to_usbdev(usb->intf);
1259 	return scnprint_id(udev, buffer, size);
1260 }
1261 
1262 #ifdef DEBUG
1263 static void print_id(struct usb_device *udev)
1264 {
1265 	char buffer[40];
1266 
1267 	scnprint_id(udev, buffer, sizeof(buffer));
1268 	buffer[sizeof(buffer)-1] = 0;
1269 	dev_dbg_f(&udev->dev, "%s\n", buffer);
1270 }
1271 #else
1272 #define print_id(udev) do { } while (0)
1273 #endif
1274 
1275 static int eject_installer(struct usb_interface *intf)
1276 {
1277 	struct usb_device *udev = interface_to_usbdev(intf);
1278 	struct usb_host_interface *iface_desc = &intf->altsetting[0];
1279 	struct usb_endpoint_descriptor *endpoint;
1280 	unsigned char *cmd;
1281 	u8 bulk_out_ep;
1282 	int r;
1283 
1284 	if (iface_desc->desc.bNumEndpoints < 2)
1285 		return -ENODEV;
1286 
1287 	/* Find bulk out endpoint */
1288 	for (r = 1; r >= 0; r--) {
1289 		endpoint = &iface_desc->endpoint[r].desc;
1290 		if (usb_endpoint_dir_out(endpoint) &&
1291 		    usb_endpoint_xfer_bulk(endpoint)) {
1292 			bulk_out_ep = endpoint->bEndpointAddress;
1293 			break;
1294 		}
1295 	}
1296 	if (r == -1) {
1297 		dev_err(&udev->dev,
1298 			"zd1211rw: Could not find bulk out endpoint\n");
1299 		return -ENODEV;
1300 	}
1301 
1302 	cmd = kzalloc(31, GFP_KERNEL);
1303 	if (cmd == NULL)
1304 		return -ENODEV;
1305 
1306 	/* USB bulk command block */
1307 	cmd[0] = 0x55;	/* bulk command signature */
1308 	cmd[1] = 0x53;	/* bulk command signature */
1309 	cmd[2] = 0x42;	/* bulk command signature */
1310 	cmd[3] = 0x43;	/* bulk command signature */
1311 	cmd[14] = 6;	/* command length */
1312 
1313 	cmd[15] = 0x1b;	/* SCSI command: START STOP UNIT */
1314 	cmd[19] = 0x2;	/* eject disc */
1315 
1316 	dev_info(&udev->dev, "Ejecting virtual installer media...\n");
1317 	r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
1318 		cmd, 31, NULL, 2000);
1319 	kfree(cmd);
1320 	if (r)
1321 		return r;
1322 
1323 	/* At this point, the device disconnects and reconnects with the real
1324 	 * ID numbers. */
1325 
1326 	usb_set_intfdata(intf, NULL);
1327 	return 0;
1328 }
1329 
1330 int zd_usb_init_hw(struct zd_usb *usb)
1331 {
1332 	int r;
1333 	struct zd_mac *mac = zd_usb_to_mac(usb);
1334 
1335 	dev_dbg_f(zd_usb_dev(usb), "\n");
1336 
1337 	r = upload_firmware(usb);
1338 	if (r) {
1339 		dev_err(zd_usb_dev(usb),
1340 		       "couldn't load firmware. Error number %d\n", r);
1341 		return r;
1342 	}
1343 
1344 	r = usb_reset_configuration(zd_usb_to_usbdev(usb));
1345 	if (r) {
1346 		dev_dbg_f(zd_usb_dev(usb),
1347 			"couldn't reset configuration. Error number %d\n", r);
1348 		return r;
1349 	}
1350 
1351 	r = zd_mac_init_hw(mac->hw);
1352 	if (r) {
1353 		dev_dbg_f(zd_usb_dev(usb),
1354 		         "couldn't initialize mac. Error number %d\n", r);
1355 		return r;
1356 	}
1357 
1358 	usb->initialized = 1;
1359 	return 0;
1360 }
1361 
1362 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
1363 {
1364 	int r;
1365 	struct usb_device *udev = interface_to_usbdev(intf);
1366 	struct zd_usb *usb;
1367 	struct ieee80211_hw *hw = NULL;
1368 
1369 	print_id(udev);
1370 
1371 	if (id->driver_info & DEVICE_INSTALLER)
1372 		return eject_installer(intf);
1373 
1374 	switch (udev->speed) {
1375 	case USB_SPEED_LOW:
1376 	case USB_SPEED_FULL:
1377 	case USB_SPEED_HIGH:
1378 		break;
1379 	default:
1380 		dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1381 		r = -ENODEV;
1382 		goto error;
1383 	}
1384 
1385 	r = usb_reset_device(udev);
1386 	if (r) {
1387 		dev_err(&intf->dev,
1388 			"couldn't reset usb device. Error number %d\n", r);
1389 		goto error;
1390 	}
1391 
1392 	hw = zd_mac_alloc_hw(intf);
1393 	if (hw == NULL) {
1394 		r = -ENOMEM;
1395 		goto error;
1396 	}
1397 
1398 	usb = &zd_hw_mac(hw)->chip.usb;
1399 	usb->is_zd1211b = (id->driver_info == DEVICE_ZD1211B) != 0;
1400 
1401 	r = zd_mac_preinit_hw(hw);
1402 	if (r) {
1403 		dev_dbg_f(&intf->dev,
1404 		         "couldn't initialize mac. Error number %d\n", r);
1405 		goto error;
1406 	}
1407 
1408 	r = ieee80211_register_hw(hw);
1409 	if (r) {
1410 		dev_dbg_f(&intf->dev,
1411 			 "couldn't register device. Error number %d\n", r);
1412 		goto error;
1413 	}
1414 
1415 	dev_dbg_f(&intf->dev, "successful\n");
1416 	dev_info(&intf->dev, "%s\n", wiphy_name(hw->wiphy));
1417 	return 0;
1418 error:
1419 	usb_reset_device(interface_to_usbdev(intf));
1420 	if (hw) {
1421 		zd_mac_clear(zd_hw_mac(hw));
1422 		ieee80211_free_hw(hw);
1423 	}
1424 	return r;
1425 }
1426 
1427 static void disconnect(struct usb_interface *intf)
1428 {
1429 	struct ieee80211_hw *hw = zd_intf_to_hw(intf);
1430 	struct zd_mac *mac;
1431 	struct zd_usb *usb;
1432 
1433 	/* Either something really bad happened, or we're just dealing with
1434 	 * a DEVICE_INSTALLER. */
1435 	if (hw == NULL)
1436 		return;
1437 
1438 	mac = zd_hw_mac(hw);
1439 	usb = &mac->chip.usb;
1440 
1441 	dev_dbg_f(zd_usb_dev(usb), "\n");
1442 
1443 	ieee80211_unregister_hw(hw);
1444 
1445 	/* Just in case something has gone wrong! */
1446 	zd_usb_disable_tx(usb);
1447 	zd_usb_disable_rx(usb);
1448 	zd_usb_disable_int(usb);
1449 
1450 	/* If the disconnect has been caused by a removal of the
1451 	 * driver module, the reset allows reloading of the driver. If the
1452 	 * reset will not be executed here, the upload of the firmware in the
1453 	 * probe function caused by the reloading of the driver will fail.
1454 	 */
1455 	usb_reset_device(interface_to_usbdev(intf));
1456 
1457 	zd_mac_clear(mac);
1458 	ieee80211_free_hw(hw);
1459 	dev_dbg(&intf->dev, "disconnected\n");
1460 }
1461 
1462 static void zd_usb_resume(struct zd_usb *usb)
1463 {
1464 	struct zd_mac *mac = zd_usb_to_mac(usb);
1465 	int r;
1466 
1467 	dev_dbg_f(zd_usb_dev(usb), "\n");
1468 
1469 	r = zd_op_start(zd_usb_to_hw(usb));
1470 	if (r < 0) {
1471 		dev_warn(zd_usb_dev(usb), "Device resume failed "
1472 			 "with error code %d. Retrying...\n", r);
1473 		if (usb->was_running)
1474 			set_bit(ZD_DEVICE_RUNNING, &mac->flags);
1475 		usb_queue_reset_device(usb->intf);
1476 		return;
1477 	}
1478 
1479 	if (mac->type != NL80211_IFTYPE_UNSPECIFIED) {
1480 		r = zd_restore_settings(mac);
1481 		if (r < 0) {
1482 			dev_dbg(zd_usb_dev(usb),
1483 				"failed to restore settings, %d\n", r);
1484 			return;
1485 		}
1486 	}
1487 }
1488 
1489 static void zd_usb_stop(struct zd_usb *usb)
1490 {
1491 	dev_dbg_f(zd_usb_dev(usb), "\n");
1492 
1493 	zd_op_stop(zd_usb_to_hw(usb));
1494 
1495 	zd_usb_disable_tx(usb);
1496 	zd_usb_disable_rx(usb);
1497 	zd_usb_disable_int(usb);
1498 
1499 	usb->initialized = 0;
1500 }
1501 
1502 static int pre_reset(struct usb_interface *intf)
1503 {
1504 	struct ieee80211_hw *hw = usb_get_intfdata(intf);
1505 	struct zd_mac *mac;
1506 	struct zd_usb *usb;
1507 
1508 	if (!hw || intf->condition != USB_INTERFACE_BOUND)
1509 		return 0;
1510 
1511 	mac = zd_hw_mac(hw);
1512 	usb = &mac->chip.usb;
1513 
1514 	usb->was_running = test_bit(ZD_DEVICE_RUNNING, &mac->flags);
1515 
1516 	zd_usb_stop(usb);
1517 
1518 	mutex_lock(&mac->chip.mutex);
1519 	return 0;
1520 }
1521 
1522 static int post_reset(struct usb_interface *intf)
1523 {
1524 	struct ieee80211_hw *hw = usb_get_intfdata(intf);
1525 	struct zd_mac *mac;
1526 	struct zd_usb *usb;
1527 
1528 	if (!hw || intf->condition != USB_INTERFACE_BOUND)
1529 		return 0;
1530 
1531 	mac = zd_hw_mac(hw);
1532 	usb = &mac->chip.usb;
1533 
1534 	mutex_unlock(&mac->chip.mutex);
1535 
1536 	if (usb->was_running)
1537 		zd_usb_resume(usb);
1538 	return 0;
1539 }
1540 
1541 static struct usb_driver driver = {
1542 	.name		= KBUILD_MODNAME,
1543 	.id_table	= usb_ids,
1544 	.probe		= probe,
1545 	.disconnect	= disconnect,
1546 	.pre_reset	= pre_reset,
1547 	.post_reset	= post_reset,
1548 	.disable_hub_initiated_lpm = 1,
1549 };
1550 
1551 struct workqueue_struct *zd_workqueue;
1552 
1553 static int __init usb_init(void)
1554 {
1555 	int r;
1556 
1557 	pr_debug("%s usb_init()\n", driver.name);
1558 
1559 	zd_workqueue = create_singlethread_workqueue(driver.name);
1560 	if (zd_workqueue == NULL) {
1561 		printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1562 		return -ENOMEM;
1563 	}
1564 
1565 	r = usb_register(&driver);
1566 	if (r) {
1567 		destroy_workqueue(zd_workqueue);
1568 		printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1569 		       driver.name, r);
1570 		return r;
1571 	}
1572 
1573 	pr_debug("%s initialized\n", driver.name);
1574 	return 0;
1575 }
1576 
1577 static void __exit usb_exit(void)
1578 {
1579 	pr_debug("%s usb_exit()\n", driver.name);
1580 	usb_deregister(&driver);
1581 	destroy_workqueue(zd_workqueue);
1582 }
1583 
1584 module_init(usb_init);
1585 module_exit(usb_exit);
1586 
1587 static int zd_ep_regs_out_msg(struct usb_device *udev, void *data, int len,
1588 			      int *actual_length, int timeout)
1589 {
1590 	/* In USB 2.0 mode EP_REGS_OUT endpoint is interrupt type. However in
1591 	 * USB 1.1 mode endpoint is bulk. Select correct type URB by endpoint
1592 	 * descriptor.
1593 	 */
1594 	struct usb_host_endpoint *ep;
1595 	unsigned int pipe;
1596 
1597 	pipe = usb_sndintpipe(udev, EP_REGS_OUT);
1598 	ep = usb_pipe_endpoint(udev, pipe);
1599 	if (!ep)
1600 		return -EINVAL;
1601 
1602 	if (usb_endpoint_xfer_int(&ep->desc)) {
1603 		return usb_interrupt_msg(udev, pipe, data, len,
1604 					 actual_length, timeout);
1605 	} else {
1606 		pipe = usb_sndbulkpipe(udev, EP_REGS_OUT);
1607 		return usb_bulk_msg(udev, pipe, data, len, actual_length,
1608 				    timeout);
1609 	}
1610 }
1611 
1612 static int usb_int_regs_length(unsigned int count)
1613 {
1614 	return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1615 }
1616 
1617 static void prepare_read_regs_int(struct zd_usb *usb,
1618 				  struct usb_req_read_regs *req,
1619 				  unsigned int count)
1620 {
1621 	struct zd_usb_interrupt *intr = &usb->intr;
1622 
1623 	spin_lock_irq(&intr->lock);
1624 	atomic_set(&intr->read_regs_enabled, 1);
1625 	intr->read_regs.req = req;
1626 	intr->read_regs.req_count = count;
1627 	reinit_completion(&intr->read_regs.completion);
1628 	spin_unlock_irq(&intr->lock);
1629 }
1630 
1631 static void disable_read_regs_int(struct zd_usb *usb)
1632 {
1633 	struct zd_usb_interrupt *intr = &usb->intr;
1634 
1635 	spin_lock_irq(&intr->lock);
1636 	atomic_set(&intr->read_regs_enabled, 0);
1637 	spin_unlock_irq(&intr->lock);
1638 }
1639 
1640 static bool check_read_regs(struct zd_usb *usb, struct usb_req_read_regs *req,
1641 			    unsigned int count)
1642 {
1643 	int i;
1644 	struct zd_usb_interrupt *intr = &usb->intr;
1645 	struct read_regs_int *rr = &intr->read_regs;
1646 	struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1647 
1648 	/* The created block size seems to be larger than expected.
1649 	 * However results appear to be correct.
1650 	 */
1651 	if (rr->length < usb_int_regs_length(count)) {
1652 		dev_dbg_f(zd_usb_dev(usb),
1653 			 "error: actual length %d less than expected %d\n",
1654 			 rr->length, usb_int_regs_length(count));
1655 		return false;
1656 	}
1657 
1658 	if (rr->length > sizeof(rr->buffer)) {
1659 		dev_dbg_f(zd_usb_dev(usb),
1660 			 "error: actual length %d exceeds buffer size %zu\n",
1661 			 rr->length, sizeof(rr->buffer));
1662 		return false;
1663 	}
1664 
1665 	for (i = 0; i < count; i++) {
1666 		struct reg_data *rd = &regs->regs[i];
1667 		if (rd->addr != req->addr[i]) {
1668 			dev_dbg_f(zd_usb_dev(usb),
1669 				 "rd[%d] addr %#06hx expected %#06hx\n", i,
1670 				 le16_to_cpu(rd->addr),
1671 				 le16_to_cpu(req->addr[i]));
1672 			return false;
1673 		}
1674 	}
1675 
1676 	return true;
1677 }
1678 
1679 static int get_results(struct zd_usb *usb, u16 *values,
1680 		       struct usb_req_read_regs *req, unsigned int count,
1681 		       bool *retry)
1682 {
1683 	int r;
1684 	int i;
1685 	struct zd_usb_interrupt *intr = &usb->intr;
1686 	struct read_regs_int *rr = &intr->read_regs;
1687 	struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1688 
1689 	spin_lock_irq(&intr->lock);
1690 
1691 	r = -EIO;
1692 
1693 	/* Read failed because firmware bug? */
1694 	*retry = !!intr->read_regs_int_overridden;
1695 	if (*retry)
1696 		goto error_unlock;
1697 
1698 	if (!check_read_regs(usb, req, count)) {
1699 		dev_dbg_f(zd_usb_dev(usb), "error: invalid read regs\n");
1700 		goto error_unlock;
1701 	}
1702 
1703 	for (i = 0; i < count; i++) {
1704 		struct reg_data *rd = &regs->regs[i];
1705 		values[i] = le16_to_cpu(rd->value);
1706 	}
1707 
1708 	r = 0;
1709 error_unlock:
1710 	spin_unlock_irq(&intr->lock);
1711 	return r;
1712 }
1713 
1714 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1715 	             const zd_addr_t *addresses, unsigned int count)
1716 {
1717 	int r, i, req_len, actual_req_len, try_count = 0;
1718 	struct usb_device *udev;
1719 	struct usb_req_read_regs *req = NULL;
1720 	unsigned long timeout;
1721 	bool retry = false;
1722 
1723 	if (count < 1) {
1724 		dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1725 		return -EINVAL;
1726 	}
1727 	if (count > USB_MAX_IOREAD16_COUNT) {
1728 		dev_dbg_f(zd_usb_dev(usb),
1729 			 "error: count %u exceeds possible max %u\n",
1730 			 count, USB_MAX_IOREAD16_COUNT);
1731 		return -EINVAL;
1732 	}
1733 	if (in_atomic()) {
1734 		dev_dbg_f(zd_usb_dev(usb),
1735 			 "error: io in atomic context not supported\n");
1736 		return -EWOULDBLOCK;
1737 	}
1738 	if (!usb_int_enabled(usb)) {
1739 		dev_dbg_f(zd_usb_dev(usb),
1740 			  "error: usb interrupt not enabled\n");
1741 		return -EWOULDBLOCK;
1742 	}
1743 
1744 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1745 	BUILD_BUG_ON(sizeof(struct usb_req_read_regs) + USB_MAX_IOREAD16_COUNT *
1746 		     sizeof(__le16) > sizeof(usb->req_buf));
1747 	BUG_ON(sizeof(struct usb_req_read_regs) + count * sizeof(__le16) >
1748 	       sizeof(usb->req_buf));
1749 
1750 	req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1751 	req = (void *)usb->req_buf;
1752 
1753 	req->id = cpu_to_le16(USB_REQ_READ_REGS);
1754 	for (i = 0; i < count; i++)
1755 		req->addr[i] = cpu_to_le16((u16)addresses[i]);
1756 
1757 retry_read:
1758 	try_count++;
1759 	udev = zd_usb_to_usbdev(usb);
1760 	prepare_read_regs_int(usb, req, count);
1761 	r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/);
1762 	if (r) {
1763 		dev_dbg_f(zd_usb_dev(usb),
1764 			"error in zd_ep_regs_out_msg(). Error number %d\n", r);
1765 		goto error;
1766 	}
1767 	if (req_len != actual_req_len) {
1768 		dev_dbg_f(zd_usb_dev(usb), "error in zd_ep_regs_out_msg()\n"
1769 			" req_len %d != actual_req_len %d\n",
1770 			req_len, actual_req_len);
1771 		r = -EIO;
1772 		goto error;
1773 	}
1774 
1775 	timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1776 					      msecs_to_jiffies(50));
1777 	if (!timeout) {
1778 		disable_read_regs_int(usb);
1779 		dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1780 		r = -ETIMEDOUT;
1781 		goto error;
1782 	}
1783 
1784 	r = get_results(usb, values, req, count, &retry);
1785 	if (retry && try_count < 20) {
1786 		dev_dbg_f(zd_usb_dev(usb), "read retry, tries so far: %d\n",
1787 				try_count);
1788 		goto retry_read;
1789 	}
1790 error:
1791 	return r;
1792 }
1793 
1794 static void iowrite16v_urb_complete(struct urb *urb)
1795 {
1796 	struct zd_usb *usb = urb->context;
1797 
1798 	if (urb->status && !usb->cmd_error)
1799 		usb->cmd_error = urb->status;
1800 
1801 	if (!usb->cmd_error &&
1802 			urb->actual_length != urb->transfer_buffer_length)
1803 		usb->cmd_error = -EIO;
1804 }
1805 
1806 static int zd_submit_waiting_urb(struct zd_usb *usb, bool last)
1807 {
1808 	int r = 0;
1809 	struct urb *urb = usb->urb_async_waiting;
1810 
1811 	if (!urb)
1812 		return 0;
1813 
1814 	usb->urb_async_waiting = NULL;
1815 
1816 	if (!last)
1817 		urb->transfer_flags |= URB_NO_INTERRUPT;
1818 
1819 	usb_anchor_urb(urb, &usb->submitted_cmds);
1820 	r = usb_submit_urb(urb, GFP_KERNEL);
1821 	if (r) {
1822 		usb_unanchor_urb(urb);
1823 		dev_dbg_f(zd_usb_dev(usb),
1824 			"error in usb_submit_urb(). Error number %d\n", r);
1825 		goto error;
1826 	}
1827 
1828 	/* fall-through with r == 0 */
1829 error:
1830 	usb_free_urb(urb);
1831 	return r;
1832 }
1833 
1834 void zd_usb_iowrite16v_async_start(struct zd_usb *usb)
1835 {
1836 	ZD_ASSERT(usb_anchor_empty(&usb->submitted_cmds));
1837 	ZD_ASSERT(usb->urb_async_waiting == NULL);
1838 	ZD_ASSERT(!usb->in_async);
1839 
1840 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1841 
1842 	usb->in_async = 1;
1843 	usb->cmd_error = 0;
1844 	usb->urb_async_waiting = NULL;
1845 }
1846 
1847 int zd_usb_iowrite16v_async_end(struct zd_usb *usb, unsigned int timeout)
1848 {
1849 	int r;
1850 
1851 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1852 	ZD_ASSERT(usb->in_async);
1853 
1854 	/* Submit last iowrite16v URB */
1855 	r = zd_submit_waiting_urb(usb, true);
1856 	if (r) {
1857 		dev_dbg_f(zd_usb_dev(usb),
1858 			"error in zd_submit_waiting_usb(). "
1859 			"Error number %d\n", r);
1860 
1861 		usb_kill_anchored_urbs(&usb->submitted_cmds);
1862 		goto error;
1863 	}
1864 
1865 	if (timeout)
1866 		timeout = usb_wait_anchor_empty_timeout(&usb->submitted_cmds,
1867 							timeout);
1868 	if (!timeout) {
1869 		usb_kill_anchored_urbs(&usb->submitted_cmds);
1870 		if (usb->cmd_error == -ENOENT) {
1871 			dev_dbg_f(zd_usb_dev(usb), "timed out");
1872 			r = -ETIMEDOUT;
1873 			goto error;
1874 		}
1875 	}
1876 
1877 	r = usb->cmd_error;
1878 error:
1879 	usb->in_async = 0;
1880 	return r;
1881 }
1882 
1883 int zd_usb_iowrite16v_async(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1884 			    unsigned int count)
1885 {
1886 	int r;
1887 	struct usb_device *udev;
1888 	struct usb_req_write_regs *req = NULL;
1889 	int i, req_len;
1890 	struct urb *urb;
1891 	struct usb_host_endpoint *ep;
1892 
1893 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
1894 	ZD_ASSERT(usb->in_async);
1895 
1896 	if (count == 0)
1897 		return 0;
1898 	if (count > USB_MAX_IOWRITE16_COUNT) {
1899 		dev_dbg_f(zd_usb_dev(usb),
1900 			"error: count %u exceeds possible max %u\n",
1901 			count, USB_MAX_IOWRITE16_COUNT);
1902 		return -EINVAL;
1903 	}
1904 	if (in_atomic()) {
1905 		dev_dbg_f(zd_usb_dev(usb),
1906 			"error: io in atomic context not supported\n");
1907 		return -EWOULDBLOCK;
1908 	}
1909 
1910 	udev = zd_usb_to_usbdev(usb);
1911 
1912 	ep = usb_pipe_endpoint(udev, usb_sndintpipe(udev, EP_REGS_OUT));
1913 	if (!ep)
1914 		return -ENOENT;
1915 
1916 	urb = usb_alloc_urb(0, GFP_KERNEL);
1917 	if (!urb)
1918 		return -ENOMEM;
1919 
1920 	req_len = sizeof(struct usb_req_write_regs) +
1921 		  count * sizeof(struct reg_data);
1922 	req = kmalloc(req_len, GFP_KERNEL);
1923 	if (!req) {
1924 		r = -ENOMEM;
1925 		goto error;
1926 	}
1927 
1928 	req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1929 	for (i = 0; i < count; i++) {
1930 		struct reg_data *rw  = &req->reg_writes[i];
1931 		rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1932 		rw->value = cpu_to_le16(ioreqs[i].value);
1933 	}
1934 
1935 	/* In USB 2.0 mode endpoint is interrupt type. However in USB 1.1 mode
1936 	 * endpoint is bulk. Select correct type URB by endpoint descriptor.
1937 	 */
1938 	if (usb_endpoint_xfer_int(&ep->desc))
1939 		usb_fill_int_urb(urb, udev, usb_sndintpipe(udev, EP_REGS_OUT),
1940 				 req, req_len, iowrite16v_urb_complete, usb,
1941 				 ep->desc.bInterval);
1942 	else
1943 		usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1944 				  req, req_len, iowrite16v_urb_complete, usb);
1945 
1946 	urb->transfer_flags |= URB_FREE_BUFFER;
1947 
1948 	/* Submit previous URB */
1949 	r = zd_submit_waiting_urb(usb, false);
1950 	if (r) {
1951 		dev_dbg_f(zd_usb_dev(usb),
1952 			"error in zd_submit_waiting_usb(). "
1953 			"Error number %d\n", r);
1954 		goto error;
1955 	}
1956 
1957 	/* Delay submit so that URB_NO_INTERRUPT flag can be set for all URBs
1958 	 * of currect batch except for very last.
1959 	 */
1960 	usb->urb_async_waiting = urb;
1961 	return 0;
1962 error:
1963 	usb_free_urb(urb);
1964 	return r;
1965 }
1966 
1967 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1968 			unsigned int count)
1969 {
1970 	int r;
1971 
1972 	zd_usb_iowrite16v_async_start(usb);
1973 	r = zd_usb_iowrite16v_async(usb, ioreqs, count);
1974 	if (r) {
1975 		zd_usb_iowrite16v_async_end(usb, 0);
1976 		return r;
1977 	}
1978 	return zd_usb_iowrite16v_async_end(usb, 50 /* ms */);
1979 }
1980 
1981 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1982 {
1983 	int r;
1984 	struct usb_device *udev;
1985 	struct usb_req_rfwrite *req = NULL;
1986 	int i, req_len, actual_req_len;
1987 	u16 bit_value_template;
1988 
1989 	if (in_atomic()) {
1990 		dev_dbg_f(zd_usb_dev(usb),
1991 			"error: io in atomic context not supported\n");
1992 		return -EWOULDBLOCK;
1993 	}
1994 	if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1995 		dev_dbg_f(zd_usb_dev(usb),
1996 			"error: bits %d are smaller than"
1997 			" USB_MIN_RFWRITE_BIT_COUNT %d\n",
1998 			bits, USB_MIN_RFWRITE_BIT_COUNT);
1999 		return -EINVAL;
2000 	}
2001 	if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
2002 		dev_dbg_f(zd_usb_dev(usb),
2003 			"error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
2004 			bits, USB_MAX_RFWRITE_BIT_COUNT);
2005 		return -EINVAL;
2006 	}
2007 #ifdef DEBUG
2008 	if (value & (~0UL << bits)) {
2009 		dev_dbg_f(zd_usb_dev(usb),
2010 			"error: value %#09x has bits >= %d set\n",
2011 			value, bits);
2012 		return -EINVAL;
2013 	}
2014 #endif /* DEBUG */
2015 
2016 	dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
2017 
2018 	r = zd_usb_ioread16(usb, &bit_value_template, ZD_CR203);
2019 	if (r) {
2020 		dev_dbg_f(zd_usb_dev(usb),
2021 			"error %d: Couldn't read ZD_CR203\n", r);
2022 		return r;
2023 	}
2024 	bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
2025 
2026 	ZD_ASSERT(mutex_is_locked(&zd_usb_to_chip(usb)->mutex));
2027 	BUILD_BUG_ON(sizeof(struct usb_req_rfwrite) +
2028 		     USB_MAX_RFWRITE_BIT_COUNT * sizeof(__le16) >
2029 		     sizeof(usb->req_buf));
2030 	BUG_ON(sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16) >
2031 	       sizeof(usb->req_buf));
2032 
2033 	req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
2034 	req = (void *)usb->req_buf;
2035 
2036 	req->id = cpu_to_le16(USB_REQ_WRITE_RF);
2037 	/* 1: 3683a, but not used in ZYDAS driver */
2038 	req->value = cpu_to_le16(2);
2039 	req->bits = cpu_to_le16(bits);
2040 
2041 	for (i = 0; i < bits; i++) {
2042 		u16 bv = bit_value_template;
2043 		if (value & (1 << (bits-1-i)))
2044 			bv |= RF_DATA;
2045 		req->bit_values[i] = cpu_to_le16(bv);
2046 	}
2047 
2048 	udev = zd_usb_to_usbdev(usb);
2049 	r = zd_ep_regs_out_msg(udev, req, req_len, &actual_req_len, 50 /*ms*/);
2050 	if (r) {
2051 		dev_dbg_f(zd_usb_dev(usb),
2052 			"error in zd_ep_regs_out_msg(). Error number %d\n", r);
2053 		goto out;
2054 	}
2055 	if (req_len != actual_req_len) {
2056 		dev_dbg_f(zd_usb_dev(usb), "error in zd_ep_regs_out_msg()"
2057 			" req_len %d != actual_req_len %d\n",
2058 			req_len, actual_req_len);
2059 		r = -EIO;
2060 		goto out;
2061 	}
2062 
2063 	/* FALL-THROUGH with r == 0 */
2064 out:
2065 	return r;
2066 }
2067