b0684f965761fec054bfc2ffeab014c1e329d810
[sfrench/cifs-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 <linux/kernel.h>
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/firmware.h>
22 #include <linux/device.h>
23 #include <linux/errno.h>
24 #include <linux/skbuff.h>
25 #include <linux/usb.h>
26 #include <linux/workqueue.h>
27 #include <net/ieee80211.h>
28 #include <asm/unaligned.h>
29
30 #include "zd_def.h"
31 #include "zd_netdev.h"
32 #include "zd_mac.h"
33 #include "zd_usb.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(0x0df6, 0x9075), .driver_info = DEVICE_ZD1211 },
43         { USB_DEVICE(0x157e, 0x300b), .driver_info = DEVICE_ZD1211 },
44         { USB_DEVICE(0x079b, 0x004a), .driver_info = DEVICE_ZD1211 },
45         { USB_DEVICE(0x1740, 0x2000), .driver_info = DEVICE_ZD1211 },
46         { USB_DEVICE(0x157e, 0x3204), .driver_info = DEVICE_ZD1211 },
47         { USB_DEVICE(0x0586, 0x3402), .driver_info = DEVICE_ZD1211 },
48         { USB_DEVICE(0x0b3b, 0x5630), .driver_info = DEVICE_ZD1211 },
49         { USB_DEVICE(0x0b05, 0x170c), .driver_info = DEVICE_ZD1211 },
50         { USB_DEVICE(0x1435, 0x0711), .driver_info = DEVICE_ZD1211 },
51         { USB_DEVICE(0x0586, 0x3409), .driver_info = DEVICE_ZD1211 },
52         { USB_DEVICE(0x0b3b, 0x1630), .driver_info = DEVICE_ZD1211 },
53         { USB_DEVICE(0x0586, 0x3401), .driver_info = DEVICE_ZD1211 },
54         { USB_DEVICE(0x14ea, 0xab13), .driver_info = DEVICE_ZD1211 },
55         { USB_DEVICE(0x13b1, 0x001e), .driver_info = DEVICE_ZD1211 },
56         { USB_DEVICE(0x0586, 0x3407), .driver_info = DEVICE_ZD1211 },
57         { USB_DEVICE(0x129b, 0x1666), .driver_info = DEVICE_ZD1211 },
58         /* ZD1211B */
59         { USB_DEVICE(0x0ace, 0x1215), .driver_info = DEVICE_ZD1211B },
60         { USB_DEVICE(0x157e, 0x300d), .driver_info = DEVICE_ZD1211B },
61         { USB_DEVICE(0x079b, 0x0062), .driver_info = DEVICE_ZD1211B },
62         { USB_DEVICE(0x1582, 0x6003), .driver_info = DEVICE_ZD1211B },
63         { USB_DEVICE(0x050d, 0x705c), .driver_info = DEVICE_ZD1211B },
64         { USB_DEVICE(0x083a, 0x4505), .driver_info = DEVICE_ZD1211B },
65         { USB_DEVICE(0x0471, 0x1236), .driver_info = DEVICE_ZD1211B },
66         { USB_DEVICE(0x13b1, 0x0024), .driver_info = DEVICE_ZD1211B },
67         { USB_DEVICE(0x0586, 0x340f), .driver_info = DEVICE_ZD1211B },
68         { USB_DEVICE(0x0b05, 0x171b), .driver_info = DEVICE_ZD1211B },
69         { USB_DEVICE(0x0586, 0x3410), .driver_info = DEVICE_ZD1211B },
70         { USB_DEVICE(0x0baf, 0x0121), .driver_info = DEVICE_ZD1211B },
71         { USB_DEVICE(0x0586, 0x3412), .driver_info = DEVICE_ZD1211B },
72         { USB_DEVICE(0x0586, 0x3413), .driver_info = DEVICE_ZD1211B },
73         { USB_DEVICE(0x0053, 0x5301), .driver_info = DEVICE_ZD1211B },
74         { USB_DEVICE(0x0411, 0x00da), .driver_info = DEVICE_ZD1211B },
75         { USB_DEVICE(0x2019, 0x5303), .driver_info = DEVICE_ZD1211B },
76         { USB_DEVICE(0x129b, 0x1667), .driver_info = DEVICE_ZD1211B },
77         { USB_DEVICE(0x0cde, 0x001a), .driver_info = DEVICE_ZD1211B },
78         { USB_DEVICE(0x0586, 0x340a), .driver_info = DEVICE_ZD1211B },
79         { USB_DEVICE(0x0471, 0x1237), .driver_info = DEVICE_ZD1211B },
80         /* "Driverless" devices that need ejecting */
81         { USB_DEVICE(0x0ace, 0x2011), .driver_info = DEVICE_INSTALLER },
82         { USB_DEVICE(0x0ace, 0x20ff), .driver_info = DEVICE_INSTALLER },
83         {}
84 };
85
86 MODULE_LICENSE("GPL");
87 MODULE_DESCRIPTION("USB driver for devices with the ZD1211 chip.");
88 MODULE_AUTHOR("Ulrich Kunitz");
89 MODULE_AUTHOR("Daniel Drake");
90 MODULE_VERSION("1.0");
91 MODULE_DEVICE_TABLE(usb, usb_ids);
92
93 #define FW_ZD1211_PREFIX        "zd1211/zd1211_"
94 #define FW_ZD1211B_PREFIX       "zd1211/zd1211b_"
95
96 /* USB device initialization */
97
98 static int request_fw_file(
99         const struct firmware **fw, const char *name, struct device *device)
100 {
101         int r;
102
103         dev_dbg_f(device, "fw name %s\n", name);
104
105         r = request_firmware(fw, name, device);
106         if (r)
107                 dev_err(device,
108                        "Could not load firmware file %s. Error number %d\n",
109                        name, r);
110         return r;
111 }
112
113 static inline u16 get_bcdDevice(const struct usb_device *udev)
114 {
115         return le16_to_cpu(udev->descriptor.bcdDevice);
116 }
117
118 enum upload_code_flags {
119         REBOOT = 1,
120 };
121
122 /* Ensures that MAX_TRANSFER_SIZE is even. */
123 #define MAX_TRANSFER_SIZE (USB_MAX_TRANSFER_SIZE & ~1)
124
125 static int upload_code(struct usb_device *udev,
126         const u8 *data, size_t size, u16 code_offset, int flags)
127 {
128         u8 *p;
129         int r;
130
131         /* USB request blocks need "kmalloced" buffers.
132          */
133         p = kmalloc(MAX_TRANSFER_SIZE, GFP_KERNEL);
134         if (!p) {
135                 dev_err(&udev->dev, "out of memory\n");
136                 r = -ENOMEM;
137                 goto error;
138         }
139
140         size &= ~1;
141         while (size > 0) {
142                 size_t transfer_size = size <= MAX_TRANSFER_SIZE ?
143                         size : MAX_TRANSFER_SIZE;
144
145                 dev_dbg_f(&udev->dev, "transfer size %zu\n", transfer_size);
146
147                 memcpy(p, data, transfer_size);
148                 r = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
149                         USB_REQ_FIRMWARE_DOWNLOAD,
150                         USB_DIR_OUT | USB_TYPE_VENDOR,
151                         code_offset, 0, p, transfer_size, 1000 /* ms */);
152                 if (r < 0) {
153                         dev_err(&udev->dev,
154                                "USB control request for firmware upload"
155                                " failed. Error number %d\n", r);
156                         goto error;
157                 }
158                 transfer_size = r & ~1;
159
160                 size -= transfer_size;
161                 data += transfer_size;
162                 code_offset += transfer_size/sizeof(u16);
163         }
164
165         if (flags & REBOOT) {
166                 u8 ret;
167
168                 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
169                         USB_REQ_FIRMWARE_CONFIRM,
170                         USB_DIR_IN | USB_TYPE_VENDOR,
171                         0, 0, &ret, sizeof(ret), 5000 /* ms */);
172                 if (r != sizeof(ret)) {
173                         dev_err(&udev->dev,
174                                 "control request firmeware confirmation failed."
175                                 " Return value %d\n", r);
176                         if (r >= 0)
177                                 r = -ENODEV;
178                         goto error;
179                 }
180                 if (ret & 0x80) {
181                         dev_err(&udev->dev,
182                                 "Internal error while downloading."
183                                 " Firmware confirm return value %#04x\n",
184                                 (unsigned int)ret);
185                         r = -ENODEV;
186                         goto error;
187                 }
188                 dev_dbg_f(&udev->dev, "firmware confirm return value %#04x\n",
189                         (unsigned int)ret);
190         }
191
192         r = 0;
193 error:
194         kfree(p);
195         return r;
196 }
197
198 static u16 get_word(const void *data, u16 offset)
199 {
200         const __le16 *p = data;
201         return le16_to_cpu(p[offset]);
202 }
203
204 static char *get_fw_name(struct zd_usb *usb, char *buffer, size_t size,
205                        const char* postfix)
206 {
207         scnprintf(buffer, size, "%s%s",
208                 usb->is_zd1211b ?
209                         FW_ZD1211B_PREFIX : FW_ZD1211_PREFIX,
210                 postfix);
211         return buffer;
212 }
213
214 static int handle_version_mismatch(struct zd_usb *usb,
215         const struct firmware *ub_fw)
216 {
217         struct usb_device *udev = zd_usb_to_usbdev(usb);
218         const struct firmware *ur_fw = NULL;
219         int offset;
220         int r = 0;
221         char fw_name[128];
222
223         r = request_fw_file(&ur_fw,
224                 get_fw_name(usb, fw_name, sizeof(fw_name), "ur"),
225                 &udev->dev);
226         if (r)
227                 goto error;
228
229         r = upload_code(udev, ur_fw->data, ur_fw->size, FW_START, REBOOT);
230         if (r)
231                 goto error;
232
233         offset = (E2P_BOOT_CODE_OFFSET * sizeof(u16));
234         r = upload_code(udev, ub_fw->data + offset, ub_fw->size - offset,
235                 E2P_START + E2P_BOOT_CODE_OFFSET, REBOOT);
236
237         /* At this point, the vendor driver downloads the whole firmware
238          * image, hacks around with version IDs, and uploads it again,
239          * completely overwriting the boot code. We do not do this here as
240          * it is not required on any tested devices, and it is suspected to
241          * cause problems. */
242 error:
243         release_firmware(ur_fw);
244         return r;
245 }
246
247 static int upload_firmware(struct zd_usb *usb)
248 {
249         int r;
250         u16 fw_bcdDevice;
251         u16 bcdDevice;
252         struct usb_device *udev = zd_usb_to_usbdev(usb);
253         const struct firmware *ub_fw = NULL;
254         const struct firmware *uph_fw = NULL;
255         char fw_name[128];
256
257         bcdDevice = get_bcdDevice(udev);
258
259         r = request_fw_file(&ub_fw,
260                 get_fw_name(usb, fw_name, sizeof(fw_name), "ub"),
261                 &udev->dev);
262         if (r)
263                 goto error;
264
265         fw_bcdDevice = get_word(ub_fw->data, E2P_DATA_OFFSET);
266
267         if (fw_bcdDevice != bcdDevice) {
268                 dev_info(&udev->dev,
269                         "firmware version %#06x and device bootcode version "
270                         "%#06x differ\n", fw_bcdDevice, bcdDevice);
271                 if (bcdDevice <= 0x4313)
272                         dev_warn(&udev->dev, "device has old bootcode, please "
273                                 "report success or failure\n");
274
275                 r = handle_version_mismatch(usb, ub_fw);
276                 if (r)
277                         goto error;
278         } else {
279                 dev_dbg_f(&udev->dev,
280                         "firmware device id %#06x is equal to the "
281                         "actual device id\n", fw_bcdDevice);
282         }
283
284
285         r = request_fw_file(&uph_fw,
286                 get_fw_name(usb, fw_name, sizeof(fw_name), "uphr"),
287                 &udev->dev);
288         if (r)
289                 goto error;
290
291         r = upload_code(udev, uph_fw->data, uph_fw->size, FW_START, REBOOT);
292         if (r) {
293                 dev_err(&udev->dev,
294                         "Could not upload firmware code uph. Error number %d\n",
295                         r);
296         }
297
298         /* FALL-THROUGH */
299 error:
300         release_firmware(ub_fw);
301         release_firmware(uph_fw);
302         return r;
303 }
304
305 /* Read data from device address space using "firmware interface" which does
306  * not require firmware to be loaded. */
307 int zd_usb_read_fw(struct zd_usb *usb, zd_addr_t addr, u8 *data, u16 len)
308 {
309         int r;
310         struct usb_device *udev = zd_usb_to_usbdev(usb);
311
312         r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
313                 USB_REQ_FIRMWARE_READ_DATA, USB_DIR_IN | 0x40, addr, 0,
314                 data, len, 5000);
315         if (r < 0) {
316                 dev_err(&udev->dev,
317                         "read over firmware interface failed: %d\n", r);
318                 return r;
319         } else if (r != len) {
320                 dev_err(&udev->dev,
321                         "incomplete read over firmware interface: %d/%d\n",
322                         r, len);
323                 return -EIO;
324         }
325
326         return 0;
327 }
328
329 #define urb_dev(urb) (&(urb)->dev->dev)
330
331 static inline void handle_regs_int(struct urb *urb)
332 {
333         struct zd_usb *usb = urb->context;
334         struct zd_usb_interrupt *intr = &usb->intr;
335         int len;
336
337         ZD_ASSERT(in_interrupt());
338         spin_lock(&intr->lock);
339
340         if (intr->read_regs_enabled) {
341                 intr->read_regs.length = len = urb->actual_length;
342
343                 if (len > sizeof(intr->read_regs.buffer))
344                         len = sizeof(intr->read_regs.buffer);
345                 memcpy(intr->read_regs.buffer, urb->transfer_buffer, len);
346                 intr->read_regs_enabled = 0;
347                 complete(&intr->read_regs.completion);
348                 goto out;
349         }
350
351         dev_dbg_f(urb_dev(urb), "regs interrupt ignored\n");
352 out:
353         spin_unlock(&intr->lock);
354 }
355
356 static inline void handle_retry_failed_int(struct urb *urb)
357 {
358         struct zd_usb *usb = urb->context;
359         struct zd_mac *mac = zd_usb_to_mac(usb);
360         struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
361
362         ieee->stats.tx_errors++;
363         ieee->ieee_stats.tx_retry_limit_exceeded++;
364         dev_dbg_f(urb_dev(urb), "retry failed interrupt\n");
365 }
366
367
368 static void int_urb_complete(struct urb *urb)
369 {
370         int r;
371         struct usb_int_header *hdr;
372
373         switch (urb->status) {
374         case 0:
375                 break;
376         case -ESHUTDOWN:
377         case -EINVAL:
378         case -ENODEV:
379         case -ENOENT:
380         case -ECONNRESET:
381         case -EPIPE:
382                 goto kfree;
383         default:
384                 goto resubmit;
385         }
386
387         if (urb->actual_length < sizeof(hdr)) {
388                 dev_dbg_f(urb_dev(urb), "error: urb %p to small\n", urb);
389                 goto resubmit;
390         }
391
392         hdr = urb->transfer_buffer;
393         if (hdr->type != USB_INT_TYPE) {
394                 dev_dbg_f(urb_dev(urb), "error: urb %p wrong type\n", urb);
395                 goto resubmit;
396         }
397
398         switch (hdr->id) {
399         case USB_INT_ID_REGS:
400                 handle_regs_int(urb);
401                 break;
402         case USB_INT_ID_RETRY_FAILED:
403                 handle_retry_failed_int(urb);
404                 break;
405         default:
406                 dev_dbg_f(urb_dev(urb), "error: urb %p unknown id %x\n", urb,
407                         (unsigned int)hdr->id);
408                 goto resubmit;
409         }
410
411 resubmit:
412         r = usb_submit_urb(urb, GFP_ATOMIC);
413         if (r) {
414                 dev_dbg_f(urb_dev(urb), "resubmit urb %p\n", urb);
415                 goto kfree;
416         }
417         return;
418 kfree:
419         kfree(urb->transfer_buffer);
420 }
421
422 static inline int int_urb_interval(struct usb_device *udev)
423 {
424         switch (udev->speed) {
425         case USB_SPEED_HIGH:
426                 return 4;
427         case USB_SPEED_LOW:
428                 return 10;
429         case USB_SPEED_FULL:
430         default:
431                 return 1;
432         }
433 }
434
435 static inline int usb_int_enabled(struct zd_usb *usb)
436 {
437         unsigned long flags;
438         struct zd_usb_interrupt *intr = &usb->intr;
439         struct urb *urb;
440
441         spin_lock_irqsave(&intr->lock, flags);
442         urb = intr->urb;
443         spin_unlock_irqrestore(&intr->lock, flags);
444         return urb != NULL;
445 }
446
447 int zd_usb_enable_int(struct zd_usb *usb)
448 {
449         int r;
450         struct usb_device *udev;
451         struct zd_usb_interrupt *intr = &usb->intr;
452         void *transfer_buffer = NULL;
453         struct urb *urb;
454
455         dev_dbg_f(zd_usb_dev(usb), "\n");
456
457         urb = usb_alloc_urb(0, GFP_KERNEL);
458         if (!urb) {
459                 r = -ENOMEM;
460                 goto out;
461         }
462
463         ZD_ASSERT(!irqs_disabled());
464         spin_lock_irq(&intr->lock);
465         if (intr->urb) {
466                 spin_unlock_irq(&intr->lock);
467                 r = 0;
468                 goto error_free_urb;
469         }
470         intr->urb = urb;
471         spin_unlock_irq(&intr->lock);
472
473         /* TODO: make it a DMA buffer */
474         r = -ENOMEM;
475         transfer_buffer = kmalloc(USB_MAX_EP_INT_BUFFER, GFP_KERNEL);
476         if (!transfer_buffer) {
477                 dev_dbg_f(zd_usb_dev(usb),
478                         "couldn't allocate transfer_buffer\n");
479                 goto error_set_urb_null;
480         }
481
482         udev = zd_usb_to_usbdev(usb);
483         usb_fill_int_urb(urb, udev, usb_rcvintpipe(udev, EP_INT_IN),
484                          transfer_buffer, USB_MAX_EP_INT_BUFFER,
485                          int_urb_complete, usb,
486                          intr->interval);
487
488         dev_dbg_f(zd_usb_dev(usb), "submit urb %p\n", intr->urb);
489         r = usb_submit_urb(urb, GFP_KERNEL);
490         if (r) {
491                 dev_dbg_f(zd_usb_dev(usb),
492                          "Couldn't submit urb. Error number %d\n", r);
493                 goto error;
494         }
495
496         return 0;
497 error:
498         kfree(transfer_buffer);
499 error_set_urb_null:
500         spin_lock_irq(&intr->lock);
501         intr->urb = NULL;
502         spin_unlock_irq(&intr->lock);
503 error_free_urb:
504         usb_free_urb(urb);
505 out:
506         return r;
507 }
508
509 void zd_usb_disable_int(struct zd_usb *usb)
510 {
511         unsigned long flags;
512         struct zd_usb_interrupt *intr = &usb->intr;
513         struct urb *urb;
514
515         spin_lock_irqsave(&intr->lock, flags);
516         urb = intr->urb;
517         if (!urb) {
518                 spin_unlock_irqrestore(&intr->lock, flags);
519                 return;
520         }
521         intr->urb = NULL;
522         spin_unlock_irqrestore(&intr->lock, flags);
523
524         usb_kill_urb(urb);
525         dev_dbg_f(zd_usb_dev(usb), "urb %p killed\n", urb);
526         usb_free_urb(urb);
527 }
528
529 static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
530                              unsigned int length)
531 {
532         int i;
533         struct zd_mac *mac = zd_usb_to_mac(usb);
534         const struct rx_length_info *length_info;
535
536         if (length < sizeof(struct rx_length_info)) {
537                 /* It's not a complete packet anyhow. */
538                 struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
539                 ieee->stats.rx_errors++;
540                 ieee->stats.rx_length_errors++;
541                 return;
542         }
543         length_info = (struct rx_length_info *)
544                 (buffer + length - sizeof(struct rx_length_info));
545
546         /* It might be that three frames are merged into a single URB
547          * transaction. We have to check for the length info tag.
548          *
549          * While testing we discovered that length_info might be unaligned,
550          * because if USB transactions are merged, the last packet will not
551          * be padded. Unaligned access might also happen if the length_info
552          * structure is not present.
553          */
554         if (get_unaligned(&length_info->tag) == cpu_to_le16(RX_LENGTH_INFO_TAG))
555         {
556                 unsigned int l, k, n;
557                 for (i = 0, l = 0;; i++) {
558                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
559                         if (k == 0)
560                                 return;
561                         n = l+k;
562                         if (n > length)
563                                 return;
564                         zd_mac_rx_irq(mac, buffer+l, k);
565                         if (i >= 2)
566                                 return;
567                         l = (n+3) & ~3;
568                 }
569         } else {
570                 zd_mac_rx_irq(mac, buffer, length);
571         }
572 }
573
574 static void rx_urb_complete(struct urb *urb)
575 {
576         struct zd_usb *usb;
577         struct zd_usb_rx *rx;
578         const u8 *buffer;
579         unsigned int length;
580
581         switch (urb->status) {
582         case 0:
583                 break;
584         case -ESHUTDOWN:
585         case -EINVAL:
586         case -ENODEV:
587         case -ENOENT:
588         case -ECONNRESET:
589         case -EPIPE:
590                 return;
591         default:
592                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
593                 goto resubmit;
594         }
595
596         buffer = urb->transfer_buffer;
597         length = urb->actual_length;
598         usb = urb->context;
599         rx = &usb->rx;
600
601         if (length%rx->usb_packet_size > rx->usb_packet_size-4) {
602                 /* If there is an old first fragment, we don't care. */
603                 dev_dbg_f(urb_dev(urb), "*** first fragment ***\n");
604                 ZD_ASSERT(length <= ARRAY_SIZE(rx->fragment));
605                 spin_lock(&rx->lock);
606                 memcpy(rx->fragment, buffer, length);
607                 rx->fragment_length = length;
608                 spin_unlock(&rx->lock);
609                 goto resubmit;
610         }
611
612         spin_lock(&rx->lock);
613         if (rx->fragment_length > 0) {
614                 /* We are on a second fragment, we believe */
615                 ZD_ASSERT(length + rx->fragment_length <=
616                           ARRAY_SIZE(rx->fragment));
617                 dev_dbg_f(urb_dev(urb), "*** second fragment ***\n");
618                 memcpy(rx->fragment+rx->fragment_length, buffer, length);
619                 handle_rx_packet(usb, rx->fragment,
620                                  rx->fragment_length + length);
621                 rx->fragment_length = 0;
622                 spin_unlock(&rx->lock);
623         } else {
624                 spin_unlock(&rx->lock);
625                 handle_rx_packet(usb, buffer, length);
626         }
627
628 resubmit:
629         usb_submit_urb(urb, GFP_ATOMIC);
630 }
631
632 static struct urb *alloc_urb(struct zd_usb *usb)
633 {
634         struct usb_device *udev = zd_usb_to_usbdev(usb);
635         struct urb *urb;
636         void *buffer;
637
638         urb = usb_alloc_urb(0, GFP_KERNEL);
639         if (!urb)
640                 return NULL;
641         buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
642                                   &urb->transfer_dma);
643         if (!buffer) {
644                 usb_free_urb(urb);
645                 return NULL;
646         }
647
648         usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
649                           buffer, USB_MAX_RX_SIZE,
650                           rx_urb_complete, usb);
651         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
652
653         return urb;
654 }
655
656 static void free_urb(struct urb *urb)
657 {
658         if (!urb)
659                 return;
660         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
661                         urb->transfer_buffer, urb->transfer_dma);
662         usb_free_urb(urb);
663 }
664
665 int zd_usb_enable_rx(struct zd_usb *usb)
666 {
667         int i, r;
668         struct zd_usb_rx *rx = &usb->rx;
669         struct urb **urbs;
670
671         dev_dbg_f(zd_usb_dev(usb), "\n");
672
673         r = -ENOMEM;
674         urbs = kcalloc(URBS_COUNT, sizeof(struct urb *), GFP_KERNEL);
675         if (!urbs)
676                 goto error;
677         for (i = 0; i < URBS_COUNT; i++) {
678                 urbs[i] = alloc_urb(usb);
679                 if (!urbs[i])
680                         goto error;
681         }
682
683         ZD_ASSERT(!irqs_disabled());
684         spin_lock_irq(&rx->lock);
685         if (rx->urbs) {
686                 spin_unlock_irq(&rx->lock);
687                 r = 0;
688                 goto error;
689         }
690         rx->urbs = urbs;
691         rx->urbs_count = URBS_COUNT;
692         spin_unlock_irq(&rx->lock);
693
694         for (i = 0; i < URBS_COUNT; i++) {
695                 r = usb_submit_urb(urbs[i], GFP_KERNEL);
696                 if (r)
697                         goto error_submit;
698         }
699
700         return 0;
701 error_submit:
702         for (i = 0; i < URBS_COUNT; i++) {
703                 usb_kill_urb(urbs[i]);
704         }
705         spin_lock_irq(&rx->lock);
706         rx->urbs = NULL;
707         rx->urbs_count = 0;
708         spin_unlock_irq(&rx->lock);
709 error:
710         if (urbs) {
711                 for (i = 0; i < URBS_COUNT; i++)
712                         free_urb(urbs[i]);
713         }
714         return r;
715 }
716
717 void zd_usb_disable_rx(struct zd_usb *usb)
718 {
719         int i;
720         unsigned long flags;
721         struct urb **urbs;
722         unsigned int count;
723         struct zd_usb_rx *rx = &usb->rx;
724
725         spin_lock_irqsave(&rx->lock, flags);
726         urbs = rx->urbs;
727         count = rx->urbs_count;
728         spin_unlock_irqrestore(&rx->lock, flags);
729         if (!urbs)
730                 return;
731
732         for (i = 0; i < count; i++) {
733                 usb_kill_urb(urbs[i]);
734                 free_urb(urbs[i]);
735         }
736         kfree(urbs);
737
738         spin_lock_irqsave(&rx->lock, flags);
739         rx->urbs = NULL;
740         rx->urbs_count = 0;
741         spin_unlock_irqrestore(&rx->lock, flags);
742 }
743
744 static void tx_urb_complete(struct urb *urb)
745 {
746         int r;
747
748         switch (urb->status) {
749         case 0:
750                 break;
751         case -ESHUTDOWN:
752         case -EINVAL:
753         case -ENODEV:
754         case -ENOENT:
755         case -ECONNRESET:
756         case -EPIPE:
757                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
758                 break;
759         default:
760                 dev_dbg_f(urb_dev(urb), "urb %p error %d\n", urb, urb->status);
761                 goto resubmit;
762         }
763 free_urb:
764         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
765                         urb->transfer_buffer, urb->transfer_dma);
766         usb_free_urb(urb);
767         return;
768 resubmit:
769         r = usb_submit_urb(urb, GFP_ATOMIC);
770         if (r) {
771                 dev_dbg_f(urb_dev(urb), "error resubmit urb %p %d\n", urb, r);
772                 goto free_urb;
773         }
774 }
775
776 /* Puts the frame on the USB endpoint. It doesn't wait for
777  * completion. The frame must contain the control set.
778  */
779 int zd_usb_tx(struct zd_usb *usb, const u8 *frame, unsigned int length)
780 {
781         int r;
782         struct usb_device *udev = zd_usb_to_usbdev(usb);
783         struct urb *urb;
784         void *buffer;
785
786         urb = usb_alloc_urb(0, GFP_ATOMIC);
787         if (!urb) {
788                 r = -ENOMEM;
789                 goto out;
790         }
791
792         buffer = usb_buffer_alloc(zd_usb_to_usbdev(usb), length, GFP_ATOMIC,
793                                   &urb->transfer_dma);
794         if (!buffer) {
795                 r = -ENOMEM;
796                 goto error_free_urb;
797         }
798         memcpy(buffer, frame, length);
799
800         usb_fill_bulk_urb(urb, udev, usb_sndbulkpipe(udev, EP_DATA_OUT),
801                           buffer, length, tx_urb_complete, NULL);
802         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
803
804         r = usb_submit_urb(urb, GFP_ATOMIC);
805         if (r)
806                 goto error;
807         return 0;
808 error:
809         usb_buffer_free(zd_usb_to_usbdev(usb), length, buffer,
810                         urb->transfer_dma);
811 error_free_urb:
812         usb_free_urb(urb);
813 out:
814         return r;
815 }
816
817 static inline void init_usb_interrupt(struct zd_usb *usb)
818 {
819         struct zd_usb_interrupt *intr = &usb->intr;
820
821         spin_lock_init(&intr->lock);
822         intr->interval = int_urb_interval(zd_usb_to_usbdev(usb));
823         init_completion(&intr->read_regs.completion);
824         intr->read_regs.cr_int_addr = cpu_to_le16((u16)CR_INTERRUPT);
825 }
826
827 static inline void init_usb_rx(struct zd_usb *usb)
828 {
829         struct zd_usb_rx *rx = &usb->rx;
830         spin_lock_init(&rx->lock);
831         if (interface_to_usbdev(usb->intf)->speed == USB_SPEED_HIGH) {
832                 rx->usb_packet_size = 512;
833         } else {
834                 rx->usb_packet_size = 64;
835         }
836         ZD_ASSERT(rx->fragment_length == 0);
837 }
838
839 static inline void init_usb_tx(struct zd_usb *usb)
840 {
841         /* FIXME: at this point we will allocate a fixed number of urb's for
842          * use in a cyclic scheme */
843 }
844
845 void zd_usb_init(struct zd_usb *usb, struct net_device *netdev,
846                  struct usb_interface *intf)
847 {
848         memset(usb, 0, sizeof(*usb));
849         usb->intf = usb_get_intf(intf);
850         usb_set_intfdata(usb->intf, netdev);
851         init_usb_interrupt(usb);
852         init_usb_tx(usb);
853         init_usb_rx(usb);
854 }
855
856 void zd_usb_clear(struct zd_usb *usb)
857 {
858         usb_set_intfdata(usb->intf, NULL);
859         usb_put_intf(usb->intf);
860         ZD_MEMCLEAR(usb, sizeof(*usb));
861         /* FIXME: usb_interrupt, usb_tx, usb_rx? */
862 }
863
864 static const char *speed(enum usb_device_speed speed)
865 {
866         switch (speed) {
867         case USB_SPEED_LOW:
868                 return "low";
869         case USB_SPEED_FULL:
870                 return "full";
871         case USB_SPEED_HIGH:
872                 return "high";
873         default:
874                 return "unknown speed";
875         }
876 }
877
878 static int scnprint_id(struct usb_device *udev, char *buffer, size_t size)
879 {
880         return scnprintf(buffer, size, "%04hx:%04hx v%04hx %s",
881                 le16_to_cpu(udev->descriptor.idVendor),
882                 le16_to_cpu(udev->descriptor.idProduct),
883                 get_bcdDevice(udev),
884                 speed(udev->speed));
885 }
886
887 int zd_usb_scnprint_id(struct zd_usb *usb, char *buffer, size_t size)
888 {
889         struct usb_device *udev = interface_to_usbdev(usb->intf);
890         return scnprint_id(udev, buffer, size);
891 }
892
893 #ifdef DEBUG
894 static void print_id(struct usb_device *udev)
895 {
896         char buffer[40];
897
898         scnprint_id(udev, buffer, sizeof(buffer));
899         buffer[sizeof(buffer)-1] = 0;
900         dev_dbg_f(&udev->dev, "%s\n", buffer);
901 }
902 #else
903 #define print_id(udev) do { } while (0)
904 #endif
905
906 static int eject_installer(struct usb_interface *intf)
907 {
908         struct usb_device *udev = interface_to_usbdev(intf);
909         struct usb_host_interface *iface_desc = &intf->altsetting[0];
910         struct usb_endpoint_descriptor *endpoint;
911         unsigned char *cmd;
912         u8 bulk_out_ep;
913         int r;
914
915         /* Find bulk out endpoint */
916         endpoint = &iface_desc->endpoint[1].desc;
917         if ((endpoint->bEndpointAddress & USB_TYPE_MASK) == USB_DIR_OUT &&
918             (endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
919             USB_ENDPOINT_XFER_BULK) {
920                 bulk_out_ep = endpoint->bEndpointAddress;
921         } else {
922                 dev_err(&udev->dev,
923                         "zd1211rw: Could not find bulk out endpoint\n");
924                 return -ENODEV;
925         }
926
927         cmd = kzalloc(31, GFP_KERNEL);
928         if (cmd == NULL)
929                 return -ENODEV;
930
931         /* USB bulk command block */
932         cmd[0] = 0x55;  /* bulk command signature */
933         cmd[1] = 0x53;  /* bulk command signature */
934         cmd[2] = 0x42;  /* bulk command signature */
935         cmd[3] = 0x43;  /* bulk command signature */
936         cmd[14] = 6;    /* command length */
937
938         cmd[15] = 0x1b; /* SCSI command: START STOP UNIT */
939         cmd[19] = 0x2;  /* eject disc */
940
941         dev_info(&udev->dev, "Ejecting virtual installer media...\n");
942         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, bulk_out_ep),
943                 cmd, 31, NULL, 2000);
944         kfree(cmd);
945         if (r)
946                 return r;
947
948         /* At this point, the device disconnects and reconnects with the real
949          * ID numbers. */
950
951         usb_set_intfdata(intf, NULL);
952         return 0;
953 }
954
955 int zd_usb_init_hw(struct zd_usb *usb)
956 {
957         int r;
958         struct zd_mac *mac = zd_usb_to_mac(usb);
959
960         dev_dbg_f(zd_usb_dev(usb), "\n");
961
962         r = upload_firmware(usb);
963         if (r) {
964                 dev_err(zd_usb_dev(usb),
965                        "couldn't load firmware. Error number %d\n", r);
966                 return r;
967         }
968
969         r = usb_reset_configuration(zd_usb_to_usbdev(usb));
970         if (r) {
971                 dev_dbg_f(zd_usb_dev(usb),
972                         "couldn't reset configuration. Error number %d\n", r);
973                 return r;
974         }
975
976         r = zd_mac_init_hw(mac);
977         if (r) {
978                 dev_dbg_f(zd_usb_dev(usb),
979                          "couldn't initialize mac. Error number %d\n", r);
980                 return r;
981         }
982
983         usb->initialized = 1;
984         return 0;
985 }
986
987 static int probe(struct usb_interface *intf, const struct usb_device_id *id)
988 {
989         int r;
990         struct zd_usb *usb;
991         struct usb_device *udev = interface_to_usbdev(intf);
992         struct net_device *netdev = NULL;
993
994         print_id(udev);
995
996         if (id->driver_info & DEVICE_INSTALLER)
997                 return eject_installer(intf);
998
999         switch (udev->speed) {
1000         case USB_SPEED_LOW:
1001         case USB_SPEED_FULL:
1002         case USB_SPEED_HIGH:
1003                 break;
1004         default:
1005                 dev_dbg_f(&intf->dev, "Unknown USB speed\n");
1006                 r = -ENODEV;
1007                 goto error;
1008         }
1009
1010         usb_reset_device(interface_to_usbdev(intf));
1011
1012         netdev = zd_netdev_alloc(intf);
1013         if (netdev == NULL) {
1014                 r = -ENOMEM;
1015                 goto error;
1016         }
1017
1018         usb = &zd_netdev_mac(netdev)->chip.usb;
1019         usb->is_zd1211b = (id->driver_info == DEVICE_ZD1211B) != 0;
1020
1021         r = zd_mac_preinit_hw(zd_netdev_mac(netdev));
1022         if (r) {
1023                 dev_dbg_f(&intf->dev,
1024                          "couldn't initialize mac. Error number %d\n", r);
1025                 goto error;
1026         }
1027
1028         r = register_netdev(netdev);
1029         if (r) {
1030                 dev_dbg_f(&intf->dev,
1031                          "couldn't register netdev. Error number %d\n", r);
1032                 goto error;
1033         }
1034
1035         dev_dbg_f(&intf->dev, "successful\n");
1036         dev_info(&intf->dev,"%s\n", netdev->name);
1037         return 0;
1038 error:
1039         usb_reset_device(interface_to_usbdev(intf));
1040         zd_netdev_free(netdev);
1041         return r;
1042 }
1043
1044 static void disconnect(struct usb_interface *intf)
1045 {
1046         struct net_device *netdev = zd_intf_to_netdev(intf);
1047         struct zd_mac *mac = zd_netdev_mac(netdev);
1048         struct zd_usb *usb = &mac->chip.usb;
1049
1050         /* Either something really bad happened, or we're just dealing with
1051          * a DEVICE_INSTALLER. */
1052         if (netdev == NULL)
1053                 return;
1054
1055         dev_dbg_f(zd_usb_dev(usb), "\n");
1056
1057         zd_netdev_disconnect(netdev);
1058
1059         /* Just in case something has gone wrong! */
1060         zd_usb_disable_rx(usb);
1061         zd_usb_disable_int(usb);
1062
1063         /* If the disconnect has been caused by a removal of the
1064          * driver module, the reset allows reloading of the driver. If the
1065          * reset will not be executed here, the upload of the firmware in the
1066          * probe function caused by the reloading of the driver will fail.
1067          */
1068         usb_reset_device(interface_to_usbdev(intf));
1069
1070         zd_netdev_free(netdev);
1071         dev_dbg(&intf->dev, "disconnected\n");
1072 }
1073
1074 static struct usb_driver driver = {
1075         .name           = "zd1211rw",
1076         .id_table       = usb_ids,
1077         .probe          = probe,
1078         .disconnect     = disconnect,
1079 };
1080
1081 struct workqueue_struct *zd_workqueue;
1082
1083 static int __init usb_init(void)
1084 {
1085         int r;
1086
1087         pr_debug("%s usb_init()\n", driver.name);
1088
1089         zd_workqueue = create_singlethread_workqueue(driver.name);
1090         if (zd_workqueue == NULL) {
1091                 printk(KERN_ERR "%s couldn't create workqueue\n", driver.name);
1092                 return -ENOMEM;
1093         }
1094
1095         r = usb_register(&driver);
1096         if (r) {
1097                 destroy_workqueue(zd_workqueue);
1098                 printk(KERN_ERR "%s usb_register() failed. Error number %d\n",
1099                        driver.name, r);
1100                 return r;
1101         }
1102
1103         pr_debug("%s initialized\n", driver.name);
1104         return 0;
1105 }
1106
1107 static void __exit usb_exit(void)
1108 {
1109         pr_debug("%s usb_exit()\n", driver.name);
1110         usb_deregister(&driver);
1111         destroy_workqueue(zd_workqueue);
1112 }
1113
1114 module_init(usb_init);
1115 module_exit(usb_exit);
1116
1117 static int usb_int_regs_length(unsigned int count)
1118 {
1119         return sizeof(struct usb_int_regs) + count * sizeof(struct reg_data);
1120 }
1121
1122 static void prepare_read_regs_int(struct zd_usb *usb)
1123 {
1124         struct zd_usb_interrupt *intr = &usb->intr;
1125
1126         spin_lock_irq(&intr->lock);
1127         intr->read_regs_enabled = 1;
1128         INIT_COMPLETION(intr->read_regs.completion);
1129         spin_unlock_irq(&intr->lock);
1130 }
1131
1132 static void disable_read_regs_int(struct zd_usb *usb)
1133 {
1134         struct zd_usb_interrupt *intr = &usb->intr;
1135
1136         spin_lock_irq(&intr->lock);
1137         intr->read_regs_enabled = 0;
1138         spin_unlock_irq(&intr->lock);
1139 }
1140
1141 static int get_results(struct zd_usb *usb, u16 *values,
1142                        struct usb_req_read_regs *req, unsigned int count)
1143 {
1144         int r;
1145         int i;
1146         struct zd_usb_interrupt *intr = &usb->intr;
1147         struct read_regs_int *rr = &intr->read_regs;
1148         struct usb_int_regs *regs = (struct usb_int_regs *)rr->buffer;
1149
1150         spin_lock_irq(&intr->lock);
1151
1152         r = -EIO;
1153         /* The created block size seems to be larger than expected.
1154          * However results appear to be correct.
1155          */
1156         if (rr->length < usb_int_regs_length(count)) {
1157                 dev_dbg_f(zd_usb_dev(usb),
1158                          "error: actual length %d less than expected %d\n",
1159                          rr->length, usb_int_regs_length(count));
1160                 goto error_unlock;
1161         }
1162         if (rr->length > sizeof(rr->buffer)) {
1163                 dev_dbg_f(zd_usb_dev(usb),
1164                          "error: actual length %d exceeds buffer size %zu\n",
1165                          rr->length, sizeof(rr->buffer));
1166                 goto error_unlock;
1167         }
1168
1169         for (i = 0; i < count; i++) {
1170                 struct reg_data *rd = &regs->regs[i];
1171                 if (rd->addr != req->addr[i]) {
1172                         dev_dbg_f(zd_usb_dev(usb),
1173                                  "rd[%d] addr %#06hx expected %#06hx\n", i,
1174                                  le16_to_cpu(rd->addr),
1175                                  le16_to_cpu(req->addr[i]));
1176                         goto error_unlock;
1177                 }
1178                 values[i] = le16_to_cpu(rd->value);
1179         }
1180
1181         r = 0;
1182 error_unlock:
1183         spin_unlock_irq(&intr->lock);
1184         return r;
1185 }
1186
1187 int zd_usb_ioread16v(struct zd_usb *usb, u16 *values,
1188                      const zd_addr_t *addresses, unsigned int count)
1189 {
1190         int r;
1191         int i, req_len, actual_req_len;
1192         struct usb_device *udev;
1193         struct usb_req_read_regs *req = NULL;
1194         unsigned long timeout;
1195
1196         if (count < 1) {
1197                 dev_dbg_f(zd_usb_dev(usb), "error: count is zero\n");
1198                 return -EINVAL;
1199         }
1200         if (count > USB_MAX_IOREAD16_COUNT) {
1201                 dev_dbg_f(zd_usb_dev(usb),
1202                          "error: count %u exceeds possible max %u\n",
1203                          count, USB_MAX_IOREAD16_COUNT);
1204                 return -EINVAL;
1205         }
1206         if (in_atomic()) {
1207                 dev_dbg_f(zd_usb_dev(usb),
1208                          "error: io in atomic context not supported\n");
1209                 return -EWOULDBLOCK;
1210         }
1211         if (!usb_int_enabled(usb)) {
1212                  dev_dbg_f(zd_usb_dev(usb),
1213                           "error: usb interrupt not enabled\n");
1214                 return -EWOULDBLOCK;
1215         }
1216
1217         req_len = sizeof(struct usb_req_read_regs) + count * sizeof(__le16);
1218         req = kmalloc(req_len, GFP_KERNEL);
1219         if (!req)
1220                 return -ENOMEM;
1221         req->id = cpu_to_le16(USB_REQ_READ_REGS);
1222         for (i = 0; i < count; i++)
1223                 req->addr[i] = cpu_to_le16((u16)addresses[i]);
1224
1225         udev = zd_usb_to_usbdev(usb);
1226         prepare_read_regs_int(usb);
1227         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1228                          req, req_len, &actual_req_len, 1000 /* ms */);
1229         if (r) {
1230                 dev_dbg_f(zd_usb_dev(usb),
1231                         "error in usb_bulk_msg(). Error number %d\n", r);
1232                 goto error;
1233         }
1234         if (req_len != actual_req_len) {
1235                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()\n"
1236                         " req_len %d != actual_req_len %d\n",
1237                         req_len, actual_req_len);
1238                 r = -EIO;
1239                 goto error;
1240         }
1241
1242         timeout = wait_for_completion_timeout(&usb->intr.read_regs.completion,
1243                                               msecs_to_jiffies(1000));
1244         if (!timeout) {
1245                 disable_read_regs_int(usb);
1246                 dev_dbg_f(zd_usb_dev(usb), "read timed out\n");
1247                 r = -ETIMEDOUT;
1248                 goto error;
1249         }
1250
1251         r = get_results(usb, values, req, count);
1252 error:
1253         kfree(req);
1254         return r;
1255 }
1256
1257 int zd_usb_iowrite16v(struct zd_usb *usb, const struct zd_ioreq16 *ioreqs,
1258                       unsigned int count)
1259 {
1260         int r;
1261         struct usb_device *udev;
1262         struct usb_req_write_regs *req = NULL;
1263         int i, req_len, actual_req_len;
1264
1265         if (count == 0)
1266                 return 0;
1267         if (count > USB_MAX_IOWRITE16_COUNT) {
1268                 dev_dbg_f(zd_usb_dev(usb),
1269                         "error: count %u exceeds possible max %u\n",
1270                         count, USB_MAX_IOWRITE16_COUNT);
1271                 return -EINVAL;
1272         }
1273         if (in_atomic()) {
1274                 dev_dbg_f(zd_usb_dev(usb),
1275                         "error: io in atomic context not supported\n");
1276                 return -EWOULDBLOCK;
1277         }
1278
1279         req_len = sizeof(struct usb_req_write_regs) +
1280                   count * sizeof(struct reg_data);
1281         req = kmalloc(req_len, GFP_KERNEL);
1282         if (!req)
1283                 return -ENOMEM;
1284
1285         req->id = cpu_to_le16(USB_REQ_WRITE_REGS);
1286         for (i = 0; i < count; i++) {
1287                 struct reg_data *rw  = &req->reg_writes[i];
1288                 rw->addr = cpu_to_le16((u16)ioreqs[i].addr);
1289                 rw->value = cpu_to_le16(ioreqs[i].value);
1290         }
1291
1292         udev = zd_usb_to_usbdev(usb);
1293         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1294                          req, req_len, &actual_req_len, 1000 /* ms */);
1295         if (r) {
1296                 dev_dbg_f(zd_usb_dev(usb),
1297                         "error in usb_bulk_msg(). Error number %d\n", r);
1298                 goto error;
1299         }
1300         if (req_len != actual_req_len) {
1301                 dev_dbg_f(zd_usb_dev(usb),
1302                         "error in usb_bulk_msg()"
1303                         " req_len %d != actual_req_len %d\n",
1304                         req_len, actual_req_len);
1305                 r = -EIO;
1306                 goto error;
1307         }
1308
1309         /* FALL-THROUGH with r == 0 */
1310 error:
1311         kfree(req);
1312         return r;
1313 }
1314
1315 int zd_usb_rfwrite(struct zd_usb *usb, u32 value, u8 bits)
1316 {
1317         int r;
1318         struct usb_device *udev;
1319         struct usb_req_rfwrite *req = NULL;
1320         int i, req_len, actual_req_len;
1321         u16 bit_value_template;
1322
1323         if (in_atomic()) {
1324                 dev_dbg_f(zd_usb_dev(usb),
1325                         "error: io in atomic context not supported\n");
1326                 return -EWOULDBLOCK;
1327         }
1328         if (bits < USB_MIN_RFWRITE_BIT_COUNT) {
1329                 dev_dbg_f(zd_usb_dev(usb),
1330                         "error: bits %d are smaller than"
1331                         " USB_MIN_RFWRITE_BIT_COUNT %d\n",
1332                         bits, USB_MIN_RFWRITE_BIT_COUNT);
1333                 return -EINVAL;
1334         }
1335         if (bits > USB_MAX_RFWRITE_BIT_COUNT) {
1336                 dev_dbg_f(zd_usb_dev(usb),
1337                         "error: bits %d exceed USB_MAX_RFWRITE_BIT_COUNT %d\n",
1338                         bits, USB_MAX_RFWRITE_BIT_COUNT);
1339                 return -EINVAL;
1340         }
1341 #ifdef DEBUG
1342         if (value & (~0UL << bits)) {
1343                 dev_dbg_f(zd_usb_dev(usb),
1344                         "error: value %#09x has bits >= %d set\n",
1345                         value, bits);
1346                 return -EINVAL;
1347         }
1348 #endif /* DEBUG */
1349
1350         dev_dbg_f(zd_usb_dev(usb), "value %#09x bits %d\n", value, bits);
1351
1352         r = zd_usb_ioread16(usb, &bit_value_template, CR203);
1353         if (r) {
1354                 dev_dbg_f(zd_usb_dev(usb),
1355                         "error %d: Couldn't read CR203\n", r);
1356                 goto out;
1357         }
1358         bit_value_template &= ~(RF_IF_LE|RF_CLK|RF_DATA);
1359
1360         req_len = sizeof(struct usb_req_rfwrite) + bits * sizeof(__le16);
1361         req = kmalloc(req_len, GFP_KERNEL);
1362         if (!req)
1363                 return -ENOMEM;
1364
1365         req->id = cpu_to_le16(USB_REQ_WRITE_RF);
1366         /* 1: 3683a, but not used in ZYDAS driver */
1367         req->value = cpu_to_le16(2);
1368         req->bits = cpu_to_le16(bits);
1369
1370         for (i = 0; i < bits; i++) {
1371                 u16 bv = bit_value_template;
1372                 if (value & (1 << (bits-1-i)))
1373                         bv |= RF_DATA;
1374                 req->bit_values[i] = cpu_to_le16(bv);
1375         }
1376
1377         udev = zd_usb_to_usbdev(usb);
1378         r = usb_bulk_msg(udev, usb_sndbulkpipe(udev, EP_REGS_OUT),
1379                          req, req_len, &actual_req_len, 1000 /* ms */);
1380         if (r) {
1381                 dev_dbg_f(zd_usb_dev(usb),
1382                         "error in usb_bulk_msg(). Error number %d\n", r);
1383                 goto out;
1384         }
1385         if (req_len != actual_req_len) {
1386                 dev_dbg_f(zd_usb_dev(usb), "error in usb_bulk_msg()"
1387                         " req_len %d != actual_req_len %d\n",
1388                         req_len, actual_req_len);
1389                 r = -EIO;
1390                 goto out;
1391         }
1392
1393         /* FALL-THROUGH with r == 0 */
1394 out:
1395         kfree(req);
1396         return r;
1397 }