[PATCH] zd1211rw: cleanups
[linux-2.6.git] / drivers / net / wireless / zd1211rw / zd_usb.c
1 /* zd_usb.c
2  *
3  * This program is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16  */
17
18 #include <asm/unaligned.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/firmware.h>
23 #include <linux/device.h>
24 #include <linux/errno.h>
25 #include <linux/skbuff.h>
26 #include <linux/usb.h>
27 #include <net/ieee80211.h>
28
29 #include "zd_def.h"
30 #include "zd_netdev.h"
31 #include "zd_mac.h"
32 #include "zd_usb.h"
33 #include "zd_util.h"
34
35 static struct usb_device_id usb_ids[] = {
36         /* ZD1211 */
37         { USB_DEVICE(0x0ace, 0x1211), .driver_info = DEVICE_ZD1211 },
38         { USB_DEVICE(0x07b8, 0x6001), .driver_info = DEVICE_ZD1211 },
39         { USB_DEVICE(0x126f, 0xa006), .driver_info = DEVICE_ZD1211 },
40         { USB_DEVICE(0x6891, 0xa727), .driver_info = DEVICE_ZD1211 },
41         { USB_DEVICE(0x0df6, 0x9071), .driver_info = DEVICE_ZD1211 },
42         { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
43         { USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
44         { USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
45         { USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
46         { USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
47         /* ZD1211B */
48         { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
49         { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
50         { USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
51         { USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
52         /* "Driverless" devices that need ejecting */
53         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
54         {}
55 };
56
57 MODULE_LICENSE("GPL");
58 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
59 MODULE_AUTHOR("Ulrich Kunitz");
60 MODULE_AUTHOR("Daniel Drake");
61 MODULE_VERSION("1.0");
62 MODULE_DEVICE_TABLE(usb, usb_ids);
63
64 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
65 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
66
67 /* register address handling */
68
69 #ifdef DEBUG
70 static int check_addr(struct zd_usb *usb, zd_addr_t addr)
71 {
72         u32 base = ZD_ADDR_BASE(addr);
73         u32 offset = ZD_OFFSET(addr);
74
75         if ((u32)addr & ADDR_ZERO_MASK)
76                 goto invalid_address;
77         switch (base) {
78         case USB_BASE:
79                 break;
80         case CR_BASE:
81                 if (offset > CR_MAX_OFFSET) {
82                         dev_dbg(zd_usb_dev(usb),
83                                 "CR offset %#010x larger than"
84                                 " CR_MAX_OFFSET %#10x\n",
85                                 offset, CR_MAX_OFFSET);
86                         goto invalid_address;
87                 }
88                 if (offset & 1) {
89                         dev_dbg(zd_usb_dev(usb),
90                                 "CR offset %#010x is not a multiple of 2\n",
91                                 offset);
92                         goto invalid_address;
93                 }
94                 break;
95         case E2P_BASE:
96                 if (offset > E2P_MAX_OFFSET) {
97                         dev_dbg(zd_usb_dev(usb),
98                                 "E2P offset %#010x larger than"
99                                 " E2P_MAX_OFFSET %#010x\n",
100                                 offset, E2P_MAX_OFFSET);
101                         goto invalid_address;
102                 }
103                 break;
104         case FW_BASE:
105                 if (!usb->fw_base_offset) {
106                         dev_dbg(zd_usb_dev(usb),
107                                "ERROR: fw base offset has not been set\n");
108                         return -EAGAIN;
109                 }
110                 if (offset > FW_MAX_OFFSET) {
111                         dev_dbg(zd_usb_dev(usb),
112                                 "FW offset %#10x is larger than"
113                                 " FW_MAX_OFFSET %#010x\n",
114                                 offset, FW_MAX_OFFSET);
115                         goto invalid_address;
116                 }
117                 break;
118         default:
119                 dev_dbg(zd_usb_dev(usb),
120                         "address has unsupported base %#010x\n", addr);
121                 goto invalid_address;
122         }
123
124         return 0;
125 invalid_address:
126         dev_dbg(zd_usb_dev(usb),
127                 "ERROR: invalid address: %#010x\n", addr);
128         return -EINVAL;
129 }
130 #endif /* DEBUG */
131
132 static u16 usb_addr(struct zd_usb *usb, zd_addr_t addr)
133 {
134         u32 base;
135         u16 offset;
136
137         base = ZD_ADDR_BASE(addr);
138         offset = ZD_OFFSET(addr);
139
140         ZD_ASSERT(check_addr(usb, addr) == 0);
141
142         switch (base) {
143         case CR_BASE:
144                 offset += CR_BASE_OFFSET;
145                 break;
146         case E2P_BASE:
147                 offset += E2P_BASE_OFFSET;
148                 break;
149         case FW_BASE:
150                 offset += usb->fw_base_offset;
151                 break;
152         }
153
154         return offset;
155 }
156
157 /* USB device initialization */
158
159 static int request_fw_file(
160         const struct firmware **fw, const char *name, struct device *device)
161 {
162         int r;
163
164         dev_dbg_f(device, "fw name %s\n", name);
165
166         r = request_firmware(fw, name, device);
167         if (r)
168                 dev_err(device,
169                        "Could not load firmware file %s. Error number %d\n",
170                        name, r);
171         return r;
172 }
173
174 static inline u16 get_bcdDevice(const struct usb_device *udev)
175 {
176         return le16_to_cpu(udev->descriptor.bcdDevice);
177 }
178
179 enum upload_code_flags {
180         REBOOT = 1,
181 };
182
183 /* Ensures that MAX_TRANSFER_SIZE is even. */
184 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
185
186 static int upload_code(struct usb_device *udev,
187         const u8 *data, size_t size, u16 code_offset, int flags)
188 {
189         u8 *p;
190         int r;
191
192         /* USB request blocks need "kmalloced" buffers.
193          */
194         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
195         if (!p) {
196                 dev_err(&udev->dev, "out of memory\n");
197                 r = -ENOMEM;
198                 goto error;
199         }
200
201         size &= ~1;
202         while (size > 0) {
203                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
204                         size : MAX_TRANSFER_SIZE;
205
206                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
207
208                 memcpy(p, data, transfer_size);
209                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
210                         USB_REQ_FIRMWARE_DOWNLOAD,
211                         USB_DIR_OUT | USB_TYPE_VENDOR,
212                         code_offset, 0, p, transfer_size, 1000 /* ms */);
213                 if (r < 0) {
214                         dev_err(&udev->dev,
215                                "USB control request for firmware upload"
216                                " failed. Error number %d\n", r);
217                         goto error;
218                 }
219                 transfer_size = r & ~1;
220
221                 size -= transfer_size;
222                 data += transfer_size;
223                 code_offset += transfer_size/sizeof(u16);
224         }
225
226         if (flags & REBOOT) {
227                 u8 ret;
228
229                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
230                         USB_REQ_FIRMWARE_CONFIRM,
231                         USB_DIR_IN | USB_TYPE_VENDOR,
232                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
233                 if (r != sizeof(ret)) {
234                         dev_err(&udev->dev,
235                                 "control request firmeware confirmation failed."
236                                 " Return value %d\n", r);
237                         if (r >= 0)
238                                 r = -ENODEV;
239                         goto error;
240                 }
241                 if (ret & 0x80) {
242                         dev_err(&udev->dev,
243                                 "Internal error while downloading."
244                                 " Firmware confirm return value %#04x\n",
245                                 (unsigned int)ret);
246                         r = -ENODEV;
247                         goto error;
248                 }
249                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
250                         (unsigned int)ret);
251         }
252
253         r = 0;
254 error:
255         kfree(p);
256         return r;
257 }
258
259 static u16 get_word(const void *data, u16 offset)
260 {
261         const __le16 *p = data;
262         return le16_to_cpu(p[offset]);
263 }
264
265 static char *get_fw_name(char *buffer, size_t size, u8 device_type,
266                        const char* postfix)
267 {
268         scnprintf(buffer, size, "%s%s",
269                 device_type == DEVICE_ZD1211B ?
270                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
271                 postfix);
272         return buffer;
273 }
274
275 static int handle_version_mismatch(struct usb_device *udev, u8 device_type,
276         const struct firmware *ub_fw)
277 {
278         const struct firmware *ur_fw = NULL;
279         int offset;
280         int r = 0;
281         char fw_name[128];
282
283         r = request_fw_file(&ur_fw,
284                 get_fw_name(fw_name, sizeof(fw_name), device_type, "ur"),
285                 &udev->dev);
286         if (r)
287                 goto error;
288
289         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START_OFFSET,
290                 REBOOT);
291         if (r)
292                 goto error;
293
294         offset = ((EEPROM_REGS_OFFSET + EEPROM_REGS_SIZE) * sizeof(u16));
295         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
296                 E2P_BASE_OFFSET + EEPROM_REGS_SIZE, REBOOT);
297
298         /* At this point, the vendor driver downloads the whole firmware
299          * image, hacks around with version IDs, and uploads it again,
300          * completely overwriting the boot code. We do not do this here as
301          * it is not required on any tested devices, and it is suspected to
302          * cause problems. */
303 error:
304         release_firmware(ur_fw);
305         return r;
306 }
307
308 static int upload_firmware(struct usb_device *udev, u8 device_type)
309 {
310         int r;
311         u16 fw_bcdDevice;
312         u16 bcdDevice;
313         const struct firmware *ub_fw = NULL;
314         const struct firmware *uph_fw = NULL;
315         char fw_name[128];
316
317         bcdDevice = get_bcdDevice(udev);
318
319         r = request_fw_file(&ub_fw,
320                 get_fw_name(fw_name, sizeof(fw_name), device_type,  "ub"),
321                 &udev->dev);
322         if (r)
323                 goto error;
324
325         fw_bcdDevice = get_word(ub_fw->data, EEPROM_REGS_OFFSET);
326
327         if (fw_bcdDevice != bcdDevice) {
328                 dev_info(&udev->dev,
329                         "firmware version %#06x and device bootcode version "
330                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
331                 if (bcdDevice <= 0x4313)
332                         dev_warn(&udev->dev, "device has old bootcode, please "
333                                 "report success or failure\n");
334
335                 r = handle_version_mismatch(udev, device_type, ub_fw);
336                 if (r)
337                         goto error;
338         } else {
339                 dev_dbg_f(&udev->dev,
340                         "firmware device id %#06x is equal to the "
341                         "actual device id\n", fw_bcdDevice);
342         }
343
344
345         r = request_fw_file(&uph_fw,
346                 get_fw_name(fw_name, sizeof(fw_name), device_type, "uphr"),
347                 &udev->dev);
348         if (r)
349                 goto error;
350
351         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START_OFFSET,
352                         REBOOT);
353         if (r) {
354                 dev_err(&udev->dev,
355                         "Could not upload firmware code uph. Error number %d\n",
356                         r);
357         }
358
359         /* FALL-THROUGH */
360 error:
361         release_firmware(ub_fw);
362         release_firmware(uph_fw);
363         return r;
364 }
365
366 static void disable_read_regs_int(struct zd_usb *usb)
367 {
368         struct zd_usb_interrupt *intr = &usb->intr;
369
370         spin_lock(&intr->lock);
371         intr->read_regs_enabled = 0;
372         spin_unlock(&intr->lock);
373 }
374
375 #define urb_dev(urb) (&(urb)->dev->dev)
376
377 static inline void handle_regs_int(struct urb *urb)
378 {
379         struct zd_usb *usb = urb->context;
380         struct zd_usb_interrupt *intr = &usb->intr;
381         int len;
382
383         ZD_ASSERT(in_interrupt());
384         spin_lock(&intr->lock);
385
386         if (intr->read_regs_enabled) {
387                 intr->read_regs.length = len = urb->actual_length;
388
389                 if (len > sizeof(intr->read_regs.buffer))
390                         len = sizeof(intr->read_regs.buffer);
391                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
392                 intr->read_regs_enabled = 0;
393                 complete(&intr->read_regs.completion);
394                 goto out;
395         }
396
397         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
398 out:
399         spin_unlock(&intr->lock);
400 }
401
402 static inline void handle_retry_failed_int(struct urb *urb)
403 {
404         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
405 }
406
407
408 static void int_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
409 {
410         int r;
411         struct usb_int_header *hdr;
412
413         switch (urb->status) {
414         case 0:
415                 break;
416         case -ESHUTDOWN:
417         case -EINVAL:
418         case -ENODEV:
419         case -ENOENT:
420         case -ECONNRESET:
421         case -EPIPE:
422                 goto kfree;
423         default:
424                 goto resubmit;
425         }
426
427         if (urb->actual_length < sizeof(hdr)) {
428                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
429                 goto resubmit;
430         }
431
432         hdr = urb->transfer_buffer;
433         if (hdr->type != USB_INT_TYPE) {
434                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
435                 goto resubmit;
436         }
437
438         switch (hdr->id) {
439         case USB_INT_ID_REGS:
440                 handle_regs_int(urb);
441                 break;
442         case USB_INT_ID_RETRY_FAILED:
443                 handle_retry_failed_int(urb);
444                 break;
445         default:
446                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
447                         (unsigned int)hdr->id);
448                 goto resubmit;
449         }
450
451 resubmit:
452         r = usb_submit_urb(urb, GFP_ATOMIC);
453         if (r) {
454                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
455                 goto kfree;
456         }
457         return;
458 kfree:
459         kfree(urb->transfer_buffer);
460 }
461
462 static inline int int_urb_interval(struct usb_device *udev)
463 {
464         switch (udev->speed) {
465         case USB_SPEED_HIGH:
466                 return 4;
467         case USB_SPEED_LOW:
468                 return 10;
469         case USB_SPEED_FULL:
470         default:
471                 return 1;
472         }
473 }
474
475 static inline int usb_int_enabled(struct zd_usb *usb)
476 {
477         unsigned long flags;
478         struct zd_usb_interrupt *intr = &usb->intr;
479         struct urb *urb;
480
481         spin_lock_irqsave(&intr->lock, flags);
482         urb = intr->urb;
483         spin_unlock_irqrestore(&intr->lock, flags);
484         return urb != NULL;
485 }
486
487 int zd_usb_enable_int(struct zd_usb *usb)
488 {
489         int r;
490         struct usb_device *udev;
491         struct zd_usb_interrupt *intr = &usb->intr;
492         void *transfer_buffer = NULL;
493         struct urb *urb;
494
495         dev_dbg_f(zd_usb_dev(usb), "\n");
496
497         urb = usb_alloc_urb(0, GFP_NOFS);
498         if (!urb) {
499                 r = -ENOMEM;
500                 goto out;
501         }
502
503         ZD_ASSERT(!irqs_disabled());
504         spin_lock_irq(&intr->lock);
505         if (intr->urb) {
506                 spin_unlock_irq(&intr->lock);
507                 r = 0;
508                 goto error_free_urb;
509         }
510         intr->urb = urb;
511         spin_unlock_irq(&intr->lock);
512
513         /* TODO: make it a DMA buffer */
514         r = -ENOMEM;
515         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_NOFS);
516         if (!transfer_buffer) {
517                 dev_dbg_f(zd_usb_dev(usb),
518                         "couldn't allocate transfer_buffer\n");
519                 goto error_set_urb_null;
520         }
521
522         udev = zd_usb_to_usbdev(usb);
523         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
524                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
525                          int_urb_complete, usb,
526                          intr->interval);
527
528         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
529         r = usb_submit_urb(urb, GFP_NOFS);
530         if (r) {
531                 dev_dbg_f(zd_usb_dev(usb),
532                          "Couldn't submit urb. Error number %d\n", r);
533                 goto error;
534         }
535
536         return 0;
537 error:
538         kfree(transfer_buffer);
539 error_set_urb_null:
540         spin_lock_irq(&intr->lock);
541         intr->urb = NULL;
542         spin_unlock_irq(&intr->lock);
543 error_free_urb:
544         usb_free_urb(urb);
545 out:
546         return r;
547 }
548
549 void zd_usb_disable_int(struct zd_usb *usb)
550 {
551         unsigned long flags;
552         struct zd_usb_interrupt *intr = &usb->intr;
553         struct urb *urb;
554
555         spin_lock_irqsave(&intr->lock, flags);
556         urb = intr->urb;
557         if (!urb) {
558                 spin_unlock_irqrestore(&intr->lock, flags);
559                 return;
560         }
561         intr->urb = NULL;
562         spin_unlock_irqrestore(&intr->lock, flags);
563
564         usb_kill_urb(urb);
565         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
566         usb_free_urb(urb);
567 }
568
569 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
570                              unsigned int length)
571 {
572         int i;
573         struct zd_mac *mac = zd_usb_to_mac(usb);
574         const struct rx_length_info *length_info;
575
576         if (length < sizeof(struct rx_length_info)) {
577                 /* It's not a complete packet anyhow. */
578                 return;
579         }
580         length_info = (struct rx_length_info *)
581                 (buffer + length - sizeof(struct rx_length_info));
582
583         /* It might be that three frames are merged into a single URB
584          * transaction. We have to check for the length info tag.
585          *
586          * While testing we discovered that length_info might be unaligned,
587          * because if USB transactions are merged, the last packet will not
588          * be padded. Unaligned access might also happen if the length_info
589          * structure is not present.
590          */
591         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
592         {
593                 unsigned int l, k, n;
594                 for (i = 0, l = 0;; i++) {
595                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
596                         n = l+k;
597                         if (n > length)
598                                 return;
599                         zd_mac_rx(mac, buffer+l, k);
600                         if (i >= 2)
601                                 return;
602                         l = (n+3) & ~3;
603                 }
604         } else {
605                 zd_mac_rx(mac, buffer, length);
606         }
607 }
608
609 static void rx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
610 {
611         struct zd_usb *usb;
612         struct zd_usb_rx *rx;
613         const u8 *buffer;
614         unsigned int length;
615
616         switch (urb->status) {
617         case 0:
618                 break;
619         case -ESHUTDOWN:
620         case -EINVAL:
621         case -ENODEV:
622         case -ENOENT:
623         case -ECONNRESET:
624         case -EPIPE:
625                 return;
626         default:
627                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
628                 goto resubmit;
629         }
630
631         buffer = urb->transfer_buffer;
632         length = urb->actual_length;
633         usb = urb->context;
634         rx = &usb->rx;
635
636         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
637                 /* If there is an old first fragment, we don't care. */
638                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
639                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
640                 spin_lock(&rx->lock);
641                 memcpy(rx->fragment, buffer, length);
642                 rx->fragment_length = length;
643                 spin_unlock(&rx->lock);
644                 goto resubmit;
645         }
646
647         spin_lock(&rx->lock);
648         if (rx->fragment_length > 0) {
649                 /* We are on a second fragment, we believe */
650                 ZD_ASSERT(length + rx->fragment_length <=
651                           ARRAY_SIZE(rx->fragment));
652                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
653                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
654                 handle_rx_packet(usb, rx->fragment,
655                                  rx->fragment_length + length);
656                 rx->fragment_length = 0;
657                 spin_unlock(&rx->lock);
658         } else {
659                 spin_unlock(&rx->lock);
660                 handle_rx_packet(usb, buffer, length);
661         }
662
663 resubmit:
664         usb_submit_urb(urb, GFP_ATOMIC);
665 }
666
667 static struct urb *alloc_urb(struct zd_usb *usb)
668 {
669         struct usb_device *udev = zd_usb_to_usbdev(usb);
670         struct urb *urb;
671         void *buffer;
672
673         urb = usb_alloc_urb(0, GFP_NOFS);
674         if (!urb)
675                 return NULL;
676         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_NOFS,
677                                   &urb->transfer_dma);
678         if (!buffer) {
679                 usb_free_urb(urb);
680                 return NULL;
681         }
682
683         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
684                           buffer, USB_MAX_RX_SIZE,
685                           rx_urb_complete, usb);
686         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
687
688         return urb;
689 }
690
691 static void free_urb(struct urb *urb)
692 {
693         if (!urb)
694                 return;
695         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
696                         urb->transfer_buffer, urb->transfer_dma);
697         usb_free_urb(urb);
698 }
699
700 int zd_usb_enable_rx(struct zd_usb *usb)
701 {
702         int i, r;
703         struct zd_usb_rx *rx = &usb->rx;
704         struct urb **urbs;
705
706         dev_dbg_f(zd_usb_dev(usb), "\n");
707
708         r = -ENOMEM;
709         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_NOFS);
710         if (!urbs)
711                 goto error;
712         for (i = 0; i < URBS_COUNT; i++) {
713                 urbs[i] = alloc_urb(usb);
714                 if (!urbs[i])
715                         goto error;
716         }
717
718         ZD_ASSERT(!irqs_disabled());
719         spin_lock_irq(&rx->lock);
720         if (rx->urbs) {
721                 spin_unlock_irq(&rx->lock);
722                 r = 0;
723                 goto error;
724         }
725         rx->urbs = urbs;
726         rx->urbs_count = URBS_COUNT;
727         spin_unlock_irq(&rx->lock);
728
729         for (i = 0; i < URBS_COUNT; i++) {
730                 r = usb_submit_urb(urbs[i], GFP_NOFS);
731                 if (r)
732                         goto error_submit;
733         }
734
735         return 0;
736 error_submit:
737         for (i = 0; i < URBS_COUNT; i++) {
738                 usb_kill_urb(urbs[i]);
739         }
740         spin_lock_irq(&rx->lock);
741         rx->urbs = NULL;
742         rx->urbs_count = 0;
743         spin_unlock_irq(&rx->lock);
744 error:
745         if (urbs) {
746                 for (i = 0; i < URBS_COUNT; i++)
747                         free_urb(urbs[i]);
748         }
749         return r;
750 }
751
752 void zd_usb_disable_rx(struct zd_usb *usb)
753 {
754         int i;
755         unsigned long flags;
756         struct urb **urbs;
757         unsigned int count;
758         struct zd_usb_rx *rx = &usb->rx;
759
760         spin_lock_irqsave(&rx->lock, flags);
761         urbs = rx->urbs;
762         count = rx->urbs_count;
763         spin_unlock_irqrestore(&rx->lock, flags);
764         if (!urbs)
765                 return;
766
767         for (i = 0; i < count; i++) {
768                 usb_kill_urb(urbs[i]);
769                 free_urb(urbs[i]);
770         }
771         kfree(urbs);
772
773         spin_lock_irqsave(&rx->lock, flags);
774         rx->urbs = NULL;
775         rx->urbs_count = 0;
776         spin_unlock_irqrestore(&rx->lock, flags);
777 }
778
779 static void tx_urb_complete(struct urb *urb, struct pt_regs *pt_regs)
780 {
781         int r;
782
783         switch (urb->status) {
784         case 0:
785                 break;
786         case -ESHUTDOWN:
787         case -EINVAL:
788         case -ENODEV:
789         case -ENOENT:
790         case -ECONNRESET:
791         case -EPIPE:
792                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
793                 break;
794         default:
795                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
796                 goto resubmit;
797         }
798 free_urb:
799         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
800                         urb->transfer_buffer, urb->transfer_dma);
801         usb_free_urb(urb);
802         return;
803 resubmit:
804         r = usb_submit_urb(urb, GFP_ATOMIC);
805         if (r) {
806                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
807                 goto free_urb;
808         }
809 }
810
811 /* Puts the frame on the USB endpoint. It doesn't wait for
812  * completion. The frame must contain the control set.
813  */
814 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
815 {
816         int r;
817         struct usb_device *udev = zd_usb_to_usbdev(usb);
818         struct urb *urb;
819         void *buffer;
820
821         urb = usb_alloc_urb(0, GFP_ATOMIC);
822         if (!urb) {
823                 r = -ENOMEM;
824                 goto out;
825         }
826
827         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
828                                   &urb->transfer_dma);
829         if (!buffer) {
830                 r = -ENOMEM;
831                 goto error_free_urb;
832         }
833         memcpy(buffer, frame, length);
834
835         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
836                           buffer, length, tx_urb_complete, NULL);
837         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
838
839         r = usb_submit_urb(urb, GFP_ATOMIC);
840         if (r)
841                 goto error;
842         return 0;
843 error:
844         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
845                         urb->transfer_dma);
846 error_free_urb:
847         usb_free_urb(urb);
848 out:
849         return r;
850 }
851
852 static inline void init_usb_interrupt(struct zd_usb *usb)
853 {
854         struct zd_usb_interrupt *intr = &usb->intr;
855
856         spin_lock_init(&intr->lock);
857         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
858         init_completion(&intr->read_regs.completion);
859         intr->read_regs.cr_int_addr = cpu_to_le16(usb_addr(usb, CR_INTERRUPT));
860 }
861
862 static inline void init_usb_rx(struct zd_usb *usb)
863 {
864         struct zd_usb_rx *rx = &usb->rx;
865         spin_lock_init(&rx->lock);
866         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
867                 rx->usb_packet_size = 512;
868         } else {
869                 rx->usb_packet_size = 64;
870         }
871         ZD_ASSERT(rx->fragment_length == 0);
872 }
873
874 static inline void init_usb_tx(struct zd_usb *usb)
875 {
876         /* FIXME: at this point we will allocate a fixed number of urb's for
877          * use in a cyclic scheme */
878 }
879
880 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
881                  struct usb_interface *intf)
882 {
883         memset(usb, 0, sizeof(*usb));
884         usb->intf = usb_get_intf(intf);
885         usb_set_intfdata(usb->intf, netdev);
886         init_usb_interrupt(usb);
887         init_usb_tx(usb);
888         init_usb_rx(usb);
889 }
890
891 int zd_usb_init_hw(struct zd_usb *usb)
892 {
893         int r;
894         struct zd_chip *chip = zd_usb_to_chip(usb);
895
896         ZD_ASSERT(mutex_is_locked(&chip->mutex));
897         r = zd_ioread16_locked(chip, &usb->fw_base_offset,
898                         USB_REG((u16)FW_BASE_ADDR_OFFSET));
899         if (r)
900                 return r;
901         dev_dbg_f(zd_usb_dev(usb), "fw_base_offset: %#06hx\n",
902                  usb->fw_base_offset);
903
904         return 0;
905 }
906
907 void zd_usb_clear(struct zd_usb *usb)
908 {
909         usb_set_intfdata(usb->intf, NULL);
910         usb_put_intf(usb->intf);
911         ZD_MEMCLEAR(usb, sizeof(*usb));
912         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
913 }
914
915 static const char *speed(enum usb_device_speed speed)
916 {
917         switch (speed) {
918         case USB_SPEED_LOW:
919                 return "low";
920         case USB_SPEED_FULL:
921                 return "full";
922         case USB_SPEED_HIGH:
923                 return "high";
924         default:
925                 return "unknown speed";
926         }
927 }
928
929 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
930 {
931         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
932                 le16_to_cpu(udev->descriptor.idVendor),
933                 le16_to_cpu(udev->descriptor.idProduct),
934                 get_bcdDevice(udev),
935                 speed(udev->speed));
936 }
937
938 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
939 {
940         struct usb_device *udev = interface_to_usbdev(usb->intf);
941         return scnprint_id(udev, buffer, size);
942 }
943
944 #ifdef DEBUG
945 static void print_id(struct usb_device *udev)
946 {
947         char buffer[40];
948
949         scnprint_id(udev, buffer, sizeof(buffer));
950         buffer[sizeof(buffer)-1] = 0;
951         dev_dbg_f(&udev->dev, "%s\n", buffer);
952 }
953 #else
954 #define print_id(udev) do { } while (0)
955 #endif
956
957 static int eject_installer(struct usb_interface *intf)
958 {
959         struct usb_device *udev = interface_to_usbdev(intf);
960         struct usb_host_interface *iface_desc = &intf->altsetting[0];
961         struct usb_endpoint_descriptor *endpoint;
962         unsigned char *cmd;
963         u8 bulk_out_ep;
964         int r;
965
966         /* Find bulk out endpoint */
967         endpoint = &iface_desc->endpoint[1].desc;
968         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
969             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
970             USB_ENDPOINT_XFER_BULK) {
971                 bulk_out_ep = endpoint->bEndpointAddress;
972         } else {
973                 dev_err(&udev->dev,
974                         "zd1211rw: Could not find bulk out endpoint\n");
975                 return -ENODEV;
976         }
977
978         cmd = kzalloc(31, GFP_KERNEL);
979         if (cmd == NULL)
980                 return -ENODEV;
981
982         /* USB bulk command block */
983         cmd[0] = 0x55;  /* bulk command signature */
984         cmd[1] = 0x53;  /* bulk command signature */
985         cmd[2] = 0x42;  /* bulk command signature */
986         cmd[3] = 0x43;  /* bulk command signature */
987         cmd[14] = 6;    /* command length */
988
989         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
990         cmd[19] = 0x2;  /* eject disc */
991
992         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
993         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
994                 cmd, 31, NULL, 2000);
995         kfree(cmd);
996         if (r)
997                 return r;
998
999         /* At this point, the device disconnects and reconnects with the real
1000          * ID numbers. */
1001
1002         usb_set_intfdata(intf, NULL);
1003         return 0;
1004 }
1005
1006 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
1007 {
1008         int r;
1009         struct usb_device *udev = interface_to_usbdev(intf);
1010         struct net_device *netdev = NULL;
1011
1012         print_id(udev);
1013
1014         if (id->driver_info & DEVICE_INSTALLER)
1015                 return eject_installer(intf);
1016
1017         switch (udev->speed) {
1018         case USB_SPEED_LOW:
1019         case USB_SPEED_FULL:
1020         case USB_SPEED_HIGH:
1021                 break;
1022         default:
1023                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1024                 r = -ENODEV;
1025                 goto error;
1026         }
1027
1028         netdev = zd_netdev_alloc(intf);
1029         if (netdev == NULL) {
1030                 r = -ENOMEM;
1031                 goto error;
1032         }
1033
1034         r = upload_firmware(udev, id->driver_info);
1035         if (r) {
1036                 dev_err(&intf->dev,
1037                        "couldn't load firmware. Error number %d\n", r);
1038                 goto error;
1039         }
1040
1041         r = usb_reset_configuration(udev);
1042         if (r) {
1043                 dev_dbg_f(&intf->dev,
1044                         "couldn't reset configuration. Error number %d\n", r);
1045                 goto error;
1046         }
1047
1048         /* At this point the interrupt endpoint is not generally enabled. We
1049          * save the USB bandwidth until the network device is opened. But
1050          * notify that the initialization of the MAC will require the
1051          * interrupts to be temporary enabled.
1052          */
1053         r = zd_mac_init_hw(zd_netdev_mac(netdev), id->driver_info);
1054         if (r) {
1055                 dev_dbg_f(&intf->dev,
1056                          "couldn't initialize mac. Error number %d\n", r);
1057                 goto error;
1058         }
1059
1060         r = register_netdev(netdev);
1061         if (r) {
1062                 dev_dbg_f(&intf->dev,
1063                          "couldn't register netdev. Error number %d\n", r);
1064                 goto error;
1065         }
1066
1067         dev_dbg_f(&intf->dev, "successful\n");
1068         dev_info(&intf->dev,"%s\n", netdev->name);
1069         return 0;
1070 error:
1071         usb_reset_device(interface_to_usbdev(intf));
1072         zd_netdev_free(netdev);
1073         return r;
1074 }
1075
1076 static void disconnect(struct usb_interface *intf)
1077 {
1078         struct net_device *netdev = zd_intf_to_netdev(intf);
1079         struct zd_mac *mac = zd_netdev_mac(netdev);
1080         struct zd_usb *usb = &mac->chip.usb;
1081
1082         /* Either something really bad happened, or we're just dealing with
1083          * a DEVICE_INSTALLER. */
1084         if (netdev == NULL)
1085                 return;
1086
1087         dev_dbg_f(zd_usb_dev(usb), "\n");
1088
1089         zd_netdev_disconnect(netdev);
1090
1091         /* Just in case something has gone wrong! */
1092         zd_usb_disable_rx(usb);
1093         zd_usb_disable_int(usb);
1094
1095         /* If the disconnect has been caused by a removal of the
1096          * driver module, the reset allows reloading of the driver. If the
1097          * reset will not be executed here, the upload of the firmware in the
1098          * probe function caused by the reloading of the driver will fail.
1099          */
1100         usb_reset_device(interface_to_usbdev(intf));
1101
1102         zd_netdev_free(netdev);
1103         dev_dbg(&intf->dev, "disconnected\n");
1104 }
1105
1106 static struct usb_driver driver = {
1107         .name           = "zd1211rw",
1108         .id_table       = usb_ids,
1109         .probe          = probe,
1110         .disconnect     = disconnect,
1111 };
1112
1113 static int __init usb_init(void)
1114 {
1115         int r;
1116
1117         pr_debug("usb_init()\n");
1118
1119         r = usb_register(&driver);
1120         if (r) {
1121                 printk(KERN_ERR "usb_register() failed. Error number %d\n", r);
1122                 return r;
1123         }
1124
1125         pr_debug("zd1211rw initialized\n");
1126         return 0;
1127 }
1128
1129 static void __exit usb_exit(void)
1130 {
1131         pr_debug("usb_exit()\n");
1132         usb_deregister(&driver);
1133 }
1134
1135 module_init(usb_init);
1136 module_exit(usb_exit);
1137
1138 static int usb_int_regs_length(unsigned int count)
1139 {
1140         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1141 }
1142
1143 static void prepare_read_regs_int(struct zd_usb *usb)
1144 {
1145         struct zd_usb_interrupt *intr = &usb->intr;
1146
1147         spin_lock(&intr->lock);
1148         intr->read_regs_enabled = 1;
1149         INIT_COMPLETION(intr->read_regs.completion);
1150         spin_unlock(&intr->lock);
1151 }
1152
1153 static int get_results(struct zd_usb *usb, u16 *values,
1154                        struct usb_req_read_regs *req, unsigned int count)
1155 {
1156         int r;
1157         int i;
1158         struct zd_usb_interrupt *intr = &usb->intr;
1159         struct read_regs_int *rr = &intr->read_regs;
1160         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1161
1162         spin_lock(&intr->lock);
1163
1164         r = -EIO;
1165         /* The created block size seems to be larger than expected.
1166          * However results appear to be correct.
1167          */
1168         if (rr->length < usb_int_regs_length(count)) {
1169                 dev_dbg_f(zd_usb_dev(usb),
1170                          "error: actual length %d less than expected %d\n",
1171                          rr->length, usb_int_regs_length(count));
1172                 goto error_unlock;
1173         }
1174         if (rr->length > sizeof(rr->buffer)) {
1175                 dev_dbg_f(zd_usb_dev(usb),
1176                          "error: actual length %d exceeds buffer size %zu\n",
1177                          rr->length, sizeof(rr->buffer));
1178                 goto error_unlock;
1179         }
1180
1181         for (i = 0; i < count; i++) {
1182                 struct reg_data *rd = &regs->regs[i];
1183                 if (rd->addr != req->addr[i]) {
1184                         dev_dbg_f(zd_usb_dev(usb),
1185                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1186                                  le16_to_cpu(rd->addr),
1187                                  le16_to_cpu(req->addr[i]));
1188                         goto error_unlock;
1189                 }
1190                 values[i] = le16_to_cpu(rd->value);
1191         }
1192
1193         r = 0;
1194 error_unlock:
1195         spin_unlock(&intr->lock);
1196         return r;
1197 }
1198
1199 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1200                      const zd_addr_t *addresses, unsigned int count)
1201 {
1202         int r;
1203         int i, req_len, actual_req_len;
1204         struct usb_device *udev;
1205         struct usb_req_read_regs *req = NULL;
1206         unsigned long timeout;
1207
1208         if (count < 1) {
1209                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1210                 return -EINVAL;
1211         }
1212         if (count > USB_MAX_IOREAD16_COUNT) {
1213                 dev_dbg_f(zd_usb_dev(usb),
1214                          "error: count %u exceeds possible max %u\n",
1215                          count, USB_MAX_IOREAD16_COUNT);
1216                 return -EINVAL;
1217         }
1218         if (in_atomic()) {
1219                 dev_dbg_f(zd_usb_dev(usb),
1220                          "error: io in atomic context not supported\n");
1221                 return -EWOULDBLOCK;
1222         }
1223         if (!usb_int_enabled(usb)) {
1224                  dev_dbg_f(zd_usb_dev(usb),
1225                           "error: usb interrupt not enabled\n");
1226                 return -EWOULDBLOCK;
1227         }
1228
1229         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1230         req = kmalloc(req_len, GFP_NOFS);
1231         if (!req)
1232                 return -ENOMEM;
1233         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1234         for (i = 0; i < count; i++)
1235                 req->addr[i] = cpu_to_le16(usb_addr(usb, addresses[i]));
1236
1237         udev = zd_usb_to_usbdev(usb);
1238         prepare_read_regs_int(usb);
1239         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1240                          req, req_len, &actual_req_len, 1000 /* ms */);
1241         if (r) {
1242                 dev_dbg_f(zd_usb_dev(usb),
1243                         "error in usb_bulk_msg(). Error number %d\n", r);
1244                 goto error;
1245         }
1246         if (req_len != actual_req_len) {
1247                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1248                         " req_len %d != actual_req_len %d\n",
1249                         req_len, actual_req_len);
1250                 r = -EIO;
1251                 goto error;
1252         }
1253
1254         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1255                                               msecs_to_jiffies(1000));
1256         if (!timeout) {
1257                 disable_read_regs_int(usb);
1258                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1259                 r = -ETIMEDOUT;
1260                 goto error;
1261         }
1262
1263         r = get_results(usb, values, req, count);
1264 error:
1265         kfree(req);
1266         return r;
1267 }
1268
1269 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1270                       unsigned int count)
1271 {
1272         int r;
1273         struct usb_device *udev;
1274         struct usb_req_write_regs *req = NULL;
1275         int i, req_len, actual_req_len;
1276
1277         if (count == 0)
1278                 return 0;
1279         if (count > USB_MAX_IOWRITE16_COUNT) {
1280                 dev_dbg_f(zd_usb_dev(usb),
1281                         "error: count %u exceeds possible max %u\n",
1282                         count, USB_MAX_IOWRITE16_COUNT);
1283                 return -EINVAL;
1284         }
1285         if (in_atomic()) {
1286                 dev_dbg_f(zd_usb_dev(usb),
1287                         "error: io in atomic context not supported\n");
1288                 return -EWOULDBLOCK;
1289         }
1290
1291         req_len = sizeof(struct usb_req_write_regs) +
1292                   count * sizeof(struct reg_data);
1293         req = kmalloc(req_len, GFP_NOFS);
1294         if (!req)
1295                 return -ENOMEM;
1296
1297         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1298         for (i = 0; i < count; i++) {
1299                 struct reg_data *rw  = &req->reg_writes[i];
1300                 rw->addr = cpu_to_le16(usb_addr(usb, ioreqs[i].addr));
1301                 rw->value = cpu_to_le16(ioreqs[i].value);
1302         }
1303
1304         udev = zd_usb_to_usbdev(usb);
1305         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1306                          req, req_len, &actual_req_len, 1000 /* ms */);
1307         if (r) {
1308                 dev_dbg_f(zd_usb_dev(usb),
1309                         "error in usb_bulk_msg(). Error number %d\n", r);
1310                 goto error;
1311         }
1312         if (req_len != actual_req_len) {
1313                 dev_dbg_f(zd_usb_dev(usb),
1314                         "error in usb_bulk_msg()"
1315                         " req_len %d != actual_req_len %d\n",
1316                         req_len, actual_req_len);
1317                 r = -EIO;
1318                 goto error;
1319         }
1320
1321         /* FALL-THROUGH with r == 0 */
1322 error:
1323         kfree(req);
1324         return r;
1325 }
1326
1327 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1328 {
1329         int r;
1330         struct usb_device *udev;
1331         struct usb_req_rfwrite *req = NULL;
1332         int i, req_len, actual_req_len;
1333         u16 bit_value_template;
1334
1335         if (in_atomic()) {
1336                 dev_dbg_f(zd_usb_dev(usb),
1337                         "error: io in atomic context not supported\n");
1338                 return -EWOULDBLOCK;
1339         }
1340         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1341                 dev_dbg_f(zd_usb_dev(usb),
1342                         "error: bits %d are smaller than"
1343                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1344                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1345                 return -EINVAL;
1346         }
1347         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1348                 dev_dbg_f(zd_usb_dev(usb),
1349                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1350                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1351                 return -EINVAL;
1352         }
1353 #ifdef DEBUG
1354         if (value & (~0UL << bits)) {
1355                 dev_dbg_f(zd_usb_dev(usb),
1356                         "error: value %#09x has bits >= %d set\n",
1357                         value, bits);
1358                 return -EINVAL;
1359         }
1360 #endif /* DEBUG */
1361
1362         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1363
1364         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1365         if (r) {
1366                 dev_dbg_f(zd_usb_dev(usb),
1367                         "error %d: Couldn't read CR203\n", r);
1368                 goto out;
1369         }
1370         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1371
1372         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1373         req = kmalloc(req_len, GFP_NOFS);
1374         if (!req)
1375                 return -ENOMEM;
1376
1377         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1378         /* 1: 3683a, but not used in ZYDAS driver */
1379         req->value = cpu_to_le16(2);
1380         req->bits = cpu_to_le16(bits);
1381
1382         for (i = 0; i < bits; i++) {
1383                 u16 bv = bit_value_template;
1384                 if (value & (1 << (bits-1-i)))
1385                         bv |= RF_DATA;
1386                 req->bit_values[i] = cpu_to_le16(bv);
1387         }
1388
1389         udev = zd_usb_to_usbdev(usb);
1390         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1391                          req, req_len, &actual_req_len, 1000 /* ms */);
1392         if (r) {
1393                 dev_dbg_f(zd_usb_dev(usb),
1394                         "error in usb_bulk_msg(). Error number %d\n", r);
1395                 goto out;
1396         }
1397         if (req_len != actual_req_len) {
1398                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1399                         " req_len %d != actual_req_len %d\n",
1400                         req_len, actual_req_len);
1401                 r = -EIO;
1402                 goto out;
1403         }
1404
1405         /* FALL-THROUGH with r == 0 */
1406 out:
1407         kfree(req);
1408         return r;
1409 }