Merge branch 'x86-kdump-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / drivers / net / usb / net1080.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Net1080 based USB host-to-host cables
4  * Copyright (C) 2000-2005 by David Brownell
5  */
6
7 // #define      DEBUG                   // error path messages, extra info
8 // #define      VERBOSE                 // more; success messages
9
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <linux/etherdevice.h>
13 #include <linux/ethtool.h>
14 #include <linux/workqueue.h>
15 #include <linux/mii.h>
16 #include <linux/usb.h>
17 #include <linux/usb/usbnet.h>
18 #include <linux/slab.h>
19
20 #include <asm/unaligned.h>
21
22
23 /*
24  * Netchip 1080 driver ... http://www.netchip.com
25  * (Sept 2004:  End-of-life announcement has been sent.)
26  * Used in (some) LapLink cables
27  */
28
29 #define frame_errors    data[1]
30
31 /*
32  * NetChip framing of ethernet packets, supporting additional error
33  * checks for links that may drop bulk packets from inside messages.
34  * Odd USB length == always short read for last usb packet.
35  *      - nc_header
36  *      - Ethernet header (14 bytes)
37  *      - payload
38  *      - (optional padding byte, if needed so length becomes odd)
39  *      - nc_trailer
40  *
41  * This framing is to be avoided for non-NetChip devices.
42  */
43
44 struct nc_header {              // packed:
45         __le16  hdr_len;                // sizeof nc_header (LE, all)
46         __le16  packet_len;             // payload size (including ethhdr)
47         __le16  packet_id;              // detects dropped packets
48 #define MIN_HEADER      6
49
50         // all else is optional, and must start with:
51         // __le16       vendorId;       // from usb-if
52         // __le16       productId;
53 } __packed;
54
55 #define PAD_BYTE        ((unsigned char)0xAC)
56
57 struct nc_trailer {
58         __le16  packet_id;
59 } __packed;
60
61 // packets may use FLAG_FRAMING_NC and optional pad
62 #define FRAMED_SIZE(mtu) (sizeof (struct nc_header) \
63                                 + sizeof (struct ethhdr) \
64                                 + (mtu) \
65                                 + 1 \
66                                 + sizeof (struct nc_trailer))
67
68 #define MIN_FRAMED      FRAMED_SIZE(0)
69
70 /* packets _could_ be up to 64KB... */
71 #define NC_MAX_PACKET   32767
72
73
74 /*
75  * Zero means no timeout; else, how long a 64 byte bulk packet may be queued
76  * before the hardware drops it.  If that's done, the driver will need to
77  * frame network packets to guard against the dropped USB packets.  The win32
78  * driver sets this for both sides of the link.
79  */
80 #define NC_READ_TTL_MS  ((u8)255)       // ms
81
82 /*
83  * We ignore most registers and EEPROM contents.
84  */
85 #define REG_USBCTL      ((u8)0x04)
86 #define REG_TTL         ((u8)0x10)
87 #define REG_STATUS      ((u8)0x11)
88
89 /*
90  * Vendor specific requests to read/write data
91  */
92 #define REQUEST_REGISTER        ((u8)0x10)
93 #define REQUEST_EEPROM          ((u8)0x11)
94
95 static int
96 nc_vendor_read(struct usbnet *dev, u8 req, u8 regnum, u16 *retval_ptr)
97 {
98         int status = usbnet_read_cmd(dev, req,
99                                      USB_DIR_IN | USB_TYPE_VENDOR |
100                                      USB_RECIP_DEVICE,
101                                      0, regnum, retval_ptr,
102                                      sizeof *retval_ptr);
103         if (status > 0)
104                 status = 0;
105         if (!status)
106                 le16_to_cpus(retval_ptr);
107         return status;
108 }
109
110 static inline int
111 nc_register_read(struct usbnet *dev, u8 regnum, u16 *retval_ptr)
112 {
113         return nc_vendor_read(dev, REQUEST_REGISTER, regnum, retval_ptr);
114 }
115
116 // no retval ... can become async, usable in_interrupt()
117 static void
118 nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value)
119 {
120         usbnet_write_cmd(dev, req,
121                          USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
122                          value, regnum, NULL, 0);
123 }
124
125 static inline void
126 nc_register_write(struct usbnet *dev, u8 regnum, u16 value)
127 {
128         nc_vendor_write(dev, REQUEST_REGISTER, regnum, value);
129 }
130
131
132 #if 0
133 static void nc_dump_registers(struct usbnet *dev)
134 {
135         u8      reg;
136         u16     *vp = kmalloc(sizeof (u16));
137
138         if (!vp)
139                 return;
140
141         netdev_dbg(dev->net, "registers:\n");
142         for (reg = 0; reg < 0x20; reg++) {
143                 int retval;
144
145                 // reading some registers is trouble
146                 if (reg >= 0x08 && reg <= 0xf)
147                         continue;
148                 if (reg >= 0x12 && reg <= 0x1e)
149                         continue;
150
151                 retval = nc_register_read(dev, reg, vp);
152                 if (retval < 0)
153                         netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n",
154                                    reg, retval);
155                 else
156                         netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp);
157         }
158         kfree(vp);
159 }
160 #endif
161
162
163 /*-------------------------------------------------------------------------*/
164
165 /*
166  * Control register
167  */
168
169 #define USBCTL_WRITABLE_MASK    0x1f0f
170 // bits 15-13 reserved, r/o
171 #define USBCTL_ENABLE_LANG      (1 << 12)
172 #define USBCTL_ENABLE_MFGR      (1 << 11)
173 #define USBCTL_ENABLE_PROD      (1 << 10)
174 #define USBCTL_ENABLE_SERIAL    (1 << 9)
175 #define USBCTL_ENABLE_DEFAULTS  (1 << 8)
176 // bits 7-4 reserved, r/o
177 #define USBCTL_FLUSH_OTHER      (1 << 3)
178 #define USBCTL_FLUSH_THIS       (1 << 2)
179 #define USBCTL_DISCONN_OTHER    (1 << 1)
180 #define USBCTL_DISCONN_THIS     (1 << 0)
181
182 static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl)
183 {
184         netif_dbg(dev, link, dev->net,
185                   "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n",
186                   dev->udev->bus->bus_name, dev->udev->devpath,
187                   usbctl,
188                   (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "",
189                   (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "",
190                   (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "",
191                   (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "",
192                   (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "",
193
194                   (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "",
195                   (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "",
196
197                   (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "",
198                   (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "",
199
200                   usbctl & ~USBCTL_WRITABLE_MASK);
201 }
202
203 /*-------------------------------------------------------------------------*/
204
205 /*
206  * Status register
207  */
208
209 #define STATUS_PORT_A           (1 << 15)
210
211 #define STATUS_CONN_OTHER       (1 << 14)
212 #define STATUS_SUSPEND_OTHER    (1 << 13)
213 #define STATUS_MAILBOX_OTHER    (1 << 12)
214 #define STATUS_PACKETS_OTHER(n) (((n) >> 8) & 0x03)
215
216 #define STATUS_CONN_THIS        (1 << 6)
217 #define STATUS_SUSPEND_THIS     (1 << 5)
218 #define STATUS_MAILBOX_THIS     (1 << 4)
219 #define STATUS_PACKETS_THIS(n)  (((n) >> 0) & 0x03)
220
221 #define STATUS_UNSPEC_MASK      0x0c8c
222 #define STATUS_NOISE_MASK       ((u16)~(0x0303|STATUS_UNSPEC_MASK))
223
224
225 static inline void nc_dump_status(struct usbnet *dev, u16 status)
226 {
227         netif_dbg(dev, link, dev->net,
228                   "net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n",
229                   dev->udev->bus->bus_name, dev->udev->devpath,
230                   status,
231
232                   // XXX the packet counts don't seem right
233                   // (1 at reset, not 0); maybe UNSPEC too
234
235                   (status & STATUS_PORT_A) ? 'A' : 'B',
236                   STATUS_PACKETS_THIS(status),
237                   (status & STATUS_CONN_THIS) ? " CON" : "",
238                   (status & STATUS_SUSPEND_THIS) ? " SUS" : "",
239                   (status & STATUS_MAILBOX_THIS) ? " MBOX" : "",
240
241                   STATUS_PACKETS_OTHER(status),
242                   (status & STATUS_CONN_OTHER) ? " CON" : "",
243                   (status & STATUS_SUSPEND_OTHER) ? " SUS" : "",
244                   (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "",
245
246                   status & STATUS_UNSPEC_MASK);
247 }
248
249 /*-------------------------------------------------------------------------*/
250
251 /*
252  * TTL register
253  */
254
255 #define TTL_OTHER(ttl)  (0x00ff & (ttl >> 8))
256 #define MK_TTL(this,other)      ((u16)(((other)<<8)|(0x00ff&(this))))
257
258 /*-------------------------------------------------------------------------*/
259
260 static int net1080_reset(struct usbnet *dev)
261 {
262         u16             usbctl, status, ttl;
263         u16             vp;
264         int             retval;
265
266         // nc_dump_registers(dev);
267
268         if ((retval = nc_register_read(dev, REG_STATUS, &vp)) < 0) {
269                 netdev_dbg(dev->net, "can't read %s-%s status: %d\n",
270                            dev->udev->bus->bus_name, dev->udev->devpath, retval);
271                 goto done;
272         }
273         status = vp;
274         nc_dump_status(dev, status);
275
276         if ((retval = nc_register_read(dev, REG_USBCTL, &vp)) < 0) {
277                 netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval);
278                 goto done;
279         }
280         usbctl = vp;
281         nc_dump_usbctl(dev, usbctl);
282
283         nc_register_write(dev, REG_USBCTL,
284                         USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER);
285
286         if ((retval = nc_register_read(dev, REG_TTL, &vp)) < 0) {
287                 netdev_dbg(dev->net, "can't read TTL, %d\n", retval);
288                 goto done;
289         }
290         ttl = vp;
291
292         nc_register_write(dev, REG_TTL,
293                         MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) );
294         netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS);
295
296         netif_info(dev, link, dev->net, "port %c, peer %sconnected\n",
297                    (status & STATUS_PORT_A) ? 'A' : 'B',
298                    (status & STATUS_CONN_OTHER) ? "" : "dis");
299         retval = 0;
300
301 done:
302         return retval;
303 }
304
305 static int net1080_check_connect(struct usbnet *dev)
306 {
307         int                     retval;
308         u16                     status;
309         u16                     vp;
310
311         retval = nc_register_read(dev, REG_STATUS, &vp);
312         status = vp;
313         if (retval != 0) {
314                 netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval);
315                 return retval;
316         }
317         if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER)
318                 return -ENOLINK;
319         return 0;
320 }
321
322 static void nc_ensure_sync(struct usbnet *dev)
323 {
324         if (++dev->frame_errors <= 5)
325                 return;
326
327         if (usbnet_write_cmd_async(dev, REQUEST_REGISTER,
328                                         USB_DIR_OUT | USB_TYPE_VENDOR |
329                                         USB_RECIP_DEVICE,
330                                         USBCTL_FLUSH_THIS |
331                                         USBCTL_FLUSH_OTHER,
332                                         REG_USBCTL, NULL, 0))
333                 return;
334
335         netif_dbg(dev, rx_err, dev->net,
336                   "flush net1080; too many framing errors\n");
337         dev->frame_errors = 0;
338 }
339
340 static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
341 {
342         struct nc_header        *header;
343         struct nc_trailer       *trailer;
344         u16                     hdr_len, packet_len;
345
346         /* This check is no longer done by usbnet */
347         if (skb->len < dev->net->hard_header_len)
348                 return 0;
349
350         if (!(skb->len & 0x01)) {
351                 netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n",
352                            skb->len, dev->net->hard_header_len, dev->hard_mtu,
353                            dev->net->mtu);
354                 dev->net->stats.rx_frame_errors++;
355                 nc_ensure_sync(dev);
356                 return 0;
357         }
358
359         header = (struct nc_header *) skb->data;
360         hdr_len = le16_to_cpup(&header->hdr_len);
361         packet_len = le16_to_cpup(&header->packet_len);
362         if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) {
363                 dev->net->stats.rx_frame_errors++;
364                 netdev_dbg(dev->net, "packet too big, %d\n", packet_len);
365                 nc_ensure_sync(dev);
366                 return 0;
367         } else if (hdr_len < MIN_HEADER) {
368                 dev->net->stats.rx_frame_errors++;
369                 netdev_dbg(dev->net, "header too short, %d\n", hdr_len);
370                 nc_ensure_sync(dev);
371                 return 0;
372         } else if (hdr_len > MIN_HEADER) {
373                 // out of band data for us?
374                 netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER);
375                 nc_ensure_sync(dev);
376                 // switch (vendor/product ids) { ... }
377         }
378         skb_pull(skb, hdr_len);
379
380         trailer = (struct nc_trailer *)
381                 (skb->data + skb->len - sizeof *trailer);
382         skb_trim(skb, skb->len - sizeof *trailer);
383
384         if ((packet_len & 0x01) == 0) {
385                 if (skb->data [packet_len] != PAD_BYTE) {
386                         dev->net->stats.rx_frame_errors++;
387                         netdev_dbg(dev->net, "bad pad\n");
388                         return 0;
389                 }
390                 skb_trim(skb, skb->len - 1);
391         }
392         if (skb->len != packet_len) {
393                 dev->net->stats.rx_frame_errors++;
394                 netdev_dbg(dev->net, "bad packet len %d (expected %d)\n",
395                            skb->len, packet_len);
396                 nc_ensure_sync(dev);
397                 return 0;
398         }
399         if (header->packet_id != get_unaligned(&trailer->packet_id)) {
400                 dev->net->stats.rx_fifo_errors++;
401                 netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n",
402                            le16_to_cpu(header->packet_id),
403                            le16_to_cpu(trailer->packet_id));
404                 return 0;
405         }
406 #if 0
407         netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len,
408                    header->packet_len, header->packet_id);
409 #endif
410         dev->frame_errors = 0;
411         return 1;
412 }
413
414 static struct sk_buff *
415 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
416 {
417         struct sk_buff          *skb2;
418         struct nc_header        *header = NULL;
419         struct nc_trailer       *trailer = NULL;
420         int                     padlen = sizeof (struct nc_trailer);
421         int                     len = skb->len;
422
423         if (!((len + padlen + sizeof (struct nc_header)) & 0x01))
424                 padlen++;
425         if (!skb_cloned(skb)) {
426                 int     headroom = skb_headroom(skb);
427                 int     tailroom = skb_tailroom(skb);
428
429                 if (padlen <= tailroom &&
430                     sizeof(struct nc_header) <= headroom)
431                         /* There's enough head and tail room */
432                         goto encapsulate;
433
434                 if ((sizeof (struct nc_header) + padlen) <
435                                 (headroom + tailroom)) {
436                         /* There's enough total room, so just readjust */
437                         skb->data = memmove(skb->head
438                                                 + sizeof (struct nc_header),
439                                             skb->data, skb->len);
440                         skb_set_tail_pointer(skb, len);
441                         goto encapsulate;
442                 }
443         }
444
445         /* Create a new skb to use with the correct size */
446         skb2 = skb_copy_expand(skb,
447                                 sizeof (struct nc_header),
448                                 padlen,
449                                 flags);
450         dev_kfree_skb_any(skb);
451         if (!skb2)
452                 return skb2;
453         skb = skb2;
454
455 encapsulate:
456         /* header first */
457         header = skb_push(skb, sizeof *header);
458         header->hdr_len = cpu_to_le16(sizeof (*header));
459         header->packet_len = cpu_to_le16(len);
460         header->packet_id = cpu_to_le16((u16)dev->xid++);
461
462         /* maybe pad; then trailer */
463         if (!((skb->len + sizeof *trailer) & 0x01))
464                 skb_put_u8(skb, PAD_BYTE);
465         trailer = skb_put(skb, sizeof *trailer);
466         put_unaligned(header->packet_id, &trailer->packet_id);
467 #if 0
468         netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n",
469                    header->hdr_len, header->packet_len,
470                    header->packet_id);
471 #endif
472         return skb;
473 }
474
475 static int net1080_bind(struct usbnet *dev, struct usb_interface *intf)
476 {
477         unsigned        extra = sizeof (struct nc_header)
478                                 + 1
479                                 + sizeof (struct nc_trailer);
480
481         dev->net->hard_header_len += extra;
482         dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu;
483         dev->hard_mtu = NC_MAX_PACKET;
484         return usbnet_get_endpoints (dev, intf);
485 }
486
487 static const struct driver_info net1080_info = {
488         .description =  "NetChip TurboCONNECT",
489         .flags =        FLAG_POINTTOPOINT | FLAG_FRAMING_NC,
490         .bind =         net1080_bind,
491         .reset =        net1080_reset,
492         .check_connect = net1080_check_connect,
493         .rx_fixup =     net1080_rx_fixup,
494         .tx_fixup =     net1080_tx_fixup,
495 };
496
497 static const struct usb_device_id       products [] = {
498 {
499         USB_DEVICE(0x0525, 0x1080),     // NetChip ref design
500         .driver_info =  (unsigned long) &net1080_info,
501 }, {
502         USB_DEVICE(0x06D0, 0x0622),     // Laplink Gold
503         .driver_info =  (unsigned long) &net1080_info,
504 },
505         { },            // END
506 };
507 MODULE_DEVICE_TABLE(usb, products);
508
509 static struct usb_driver net1080_driver = {
510         .name =         "net1080",
511         .id_table =     products,
512         .probe =        usbnet_probe,
513         .disconnect =   usbnet_disconnect,
514         .suspend =      usbnet_suspend,
515         .resume =       usbnet_resume,
516         .disable_hub_initiated_lpm = 1,
517 };
518
519 module_usb_driver(net1080_driver);
520
521 MODULE_AUTHOR("David Brownell");
522 MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links");
523 MODULE_LICENSE("GPL");