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 <linux/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 static void 117 nc_vendor_write(struct usbnet *dev, u8 req, u8 regnum, u16 value) 118 { 119 usbnet_write_cmd(dev, req, 120 USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 121 value, regnum, NULL, 0); 122 } 123 124 static inline void 125 nc_register_write(struct usbnet *dev, u8 regnum, u16 value) 126 { 127 nc_vendor_write(dev, REQUEST_REGISTER, regnum, value); 128 } 129 130 131 #if 0 132 static void nc_dump_registers(struct usbnet *dev) 133 { 134 u8 reg; 135 u16 *vp = kmalloc(sizeof (u16)); 136 137 if (!vp) 138 return; 139 140 netdev_dbg(dev->net, "registers:\n"); 141 for (reg = 0; reg < 0x20; reg++) { 142 int retval; 143 144 // reading some registers is trouble 145 if (reg >= 0x08 && reg <= 0xf) 146 continue; 147 if (reg >= 0x12 && reg <= 0x1e) 148 continue; 149 150 retval = nc_register_read(dev, reg, vp); 151 if (retval < 0) 152 netdev_dbg(dev->net, "reg [0x%x] ==> error %d\n", 153 reg, retval); 154 else 155 netdev_dbg(dev->net, "reg [0x%x] = 0x%x\n", reg, *vp); 156 } 157 kfree(vp); 158 } 159 #endif 160 161 162 /*-------------------------------------------------------------------------*/ 163 164 /* 165 * Control register 166 */ 167 168 #define USBCTL_WRITABLE_MASK 0x1f0f 169 // bits 15-13 reserved, r/o 170 #define USBCTL_ENABLE_LANG (1 << 12) 171 #define USBCTL_ENABLE_MFGR (1 << 11) 172 #define USBCTL_ENABLE_PROD (1 << 10) 173 #define USBCTL_ENABLE_SERIAL (1 << 9) 174 #define USBCTL_ENABLE_DEFAULTS (1 << 8) 175 // bits 7-4 reserved, r/o 176 #define USBCTL_FLUSH_OTHER (1 << 3) 177 #define USBCTL_FLUSH_THIS (1 << 2) 178 #define USBCTL_DISCONN_OTHER (1 << 1) 179 #define USBCTL_DISCONN_THIS (1 << 0) 180 181 static inline void nc_dump_usbctl(struct usbnet *dev, u16 usbctl) 182 { 183 netif_dbg(dev, link, dev->net, 184 "net1080 %s-%s usbctl 0x%x:%s%s%s%s%s; this%s%s; other%s%s; r/o 0x%x\n", 185 dev->udev->bus->bus_name, dev->udev->devpath, 186 usbctl, 187 (usbctl & USBCTL_ENABLE_LANG) ? " lang" : "", 188 (usbctl & USBCTL_ENABLE_MFGR) ? " mfgr" : "", 189 (usbctl & USBCTL_ENABLE_PROD) ? " prod" : "", 190 (usbctl & USBCTL_ENABLE_SERIAL) ? " serial" : "", 191 (usbctl & USBCTL_ENABLE_DEFAULTS) ? " defaults" : "", 192 193 (usbctl & USBCTL_FLUSH_THIS) ? " FLUSH" : "", 194 (usbctl & USBCTL_DISCONN_THIS) ? " DIS" : "", 195 196 (usbctl & USBCTL_FLUSH_OTHER) ? " FLUSH" : "", 197 (usbctl & USBCTL_DISCONN_OTHER) ? " DIS" : "", 198 199 usbctl & ~USBCTL_WRITABLE_MASK); 200 } 201 202 /*-------------------------------------------------------------------------*/ 203 204 /* 205 * Status register 206 */ 207 208 #define STATUS_PORT_A (1 << 15) 209 210 #define STATUS_CONN_OTHER (1 << 14) 211 #define STATUS_SUSPEND_OTHER (1 << 13) 212 #define STATUS_MAILBOX_OTHER (1 << 12) 213 #define STATUS_PACKETS_OTHER(n) (((n) >> 8) & 0x03) 214 215 #define STATUS_CONN_THIS (1 << 6) 216 #define STATUS_SUSPEND_THIS (1 << 5) 217 #define STATUS_MAILBOX_THIS (1 << 4) 218 #define STATUS_PACKETS_THIS(n) (((n) >> 0) & 0x03) 219 220 #define STATUS_UNSPEC_MASK 0x0c8c 221 #define STATUS_NOISE_MASK ((u16)~(0x0303|STATUS_UNSPEC_MASK)) 222 223 224 static inline void nc_dump_status(struct usbnet *dev, u16 status) 225 { 226 netif_dbg(dev, link, dev->net, 227 "net1080 %s-%s status 0x%x: this (%c) PKT=%d%s%s%s; other PKT=%d%s%s%s; unspec 0x%x\n", 228 dev->udev->bus->bus_name, dev->udev->devpath, 229 status, 230 231 // XXX the packet counts don't seem right 232 // (1 at reset, not 0); maybe UNSPEC too 233 234 (status & STATUS_PORT_A) ? 'A' : 'B', 235 STATUS_PACKETS_THIS(status), 236 (status & STATUS_CONN_THIS) ? " CON" : "", 237 (status & STATUS_SUSPEND_THIS) ? " SUS" : "", 238 (status & STATUS_MAILBOX_THIS) ? " MBOX" : "", 239 240 STATUS_PACKETS_OTHER(status), 241 (status & STATUS_CONN_OTHER) ? " CON" : "", 242 (status & STATUS_SUSPEND_OTHER) ? " SUS" : "", 243 (status & STATUS_MAILBOX_OTHER) ? " MBOX" : "", 244 245 status & STATUS_UNSPEC_MASK); 246 } 247 248 /*-------------------------------------------------------------------------*/ 249 250 /* 251 * TTL register 252 */ 253 254 #define TTL_OTHER(ttl) (0x00ff & (ttl >> 8)) 255 #define MK_TTL(this,other) ((u16)(((other)<<8)|(0x00ff&(this)))) 256 257 /*-------------------------------------------------------------------------*/ 258 259 static int net1080_reset(struct usbnet *dev) 260 { 261 u16 usbctl, status, ttl; 262 u16 vp; 263 int retval; 264 265 // nc_dump_registers(dev); 266 267 if ((retval = nc_register_read(dev, REG_STATUS, &vp)) < 0) { 268 netdev_dbg(dev->net, "can't read %s-%s status: %d\n", 269 dev->udev->bus->bus_name, dev->udev->devpath, retval); 270 goto done; 271 } 272 status = vp; 273 nc_dump_status(dev, status); 274 275 if ((retval = nc_register_read(dev, REG_USBCTL, &vp)) < 0) { 276 netdev_dbg(dev->net, "can't read USBCTL, %d\n", retval); 277 goto done; 278 } 279 usbctl = vp; 280 nc_dump_usbctl(dev, usbctl); 281 282 nc_register_write(dev, REG_USBCTL, 283 USBCTL_FLUSH_THIS | USBCTL_FLUSH_OTHER); 284 285 if ((retval = nc_register_read(dev, REG_TTL, &vp)) < 0) { 286 netdev_dbg(dev->net, "can't read TTL, %d\n", retval); 287 goto done; 288 } 289 ttl = vp; 290 291 nc_register_write(dev, REG_TTL, 292 MK_TTL(NC_READ_TTL_MS, TTL_OTHER(ttl)) ); 293 netdev_dbg(dev->net, "assigned TTL, %d ms\n", NC_READ_TTL_MS); 294 295 netif_info(dev, link, dev->net, "port %c, peer %sconnected\n", 296 (status & STATUS_PORT_A) ? 'A' : 'B', 297 (status & STATUS_CONN_OTHER) ? "" : "dis"); 298 retval = 0; 299 300 done: 301 return retval; 302 } 303 304 static int net1080_check_connect(struct usbnet *dev) 305 { 306 int retval; 307 u16 status; 308 u16 vp; 309 310 retval = nc_register_read(dev, REG_STATUS, &vp); 311 status = vp; 312 if (retval != 0) { 313 netdev_dbg(dev->net, "net1080_check_conn read - %d\n", retval); 314 return retval; 315 } 316 if ((status & STATUS_CONN_OTHER) != STATUS_CONN_OTHER) 317 return -ENOLINK; 318 return 0; 319 } 320 321 static void nc_ensure_sync(struct usbnet *dev) 322 { 323 if (++dev->frame_errors <= 5) 324 return; 325 326 if (usbnet_write_cmd_async(dev, REQUEST_REGISTER, 327 USB_DIR_OUT | USB_TYPE_VENDOR | 328 USB_RECIP_DEVICE, 329 USBCTL_FLUSH_THIS | 330 USBCTL_FLUSH_OTHER, 331 REG_USBCTL, NULL, 0)) 332 return; 333 334 netif_dbg(dev, rx_err, dev->net, 335 "flush net1080; too many framing errors\n"); 336 dev->frame_errors = 0; 337 } 338 339 static int net1080_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 340 { 341 struct nc_header *header; 342 struct nc_trailer *trailer; 343 u16 hdr_len, packet_len; 344 345 /* This check is no longer done by usbnet */ 346 if (skb->len < dev->net->hard_header_len) 347 return 0; 348 349 if (!(skb->len & 0x01)) { 350 netdev_dbg(dev->net, "rx framesize %d range %d..%d mtu %d\n", 351 skb->len, dev->net->hard_header_len, dev->hard_mtu, 352 dev->net->mtu); 353 dev->net->stats.rx_frame_errors++; 354 nc_ensure_sync(dev); 355 return 0; 356 } 357 358 header = (struct nc_header *) skb->data; 359 hdr_len = le16_to_cpup(&header->hdr_len); 360 packet_len = le16_to_cpup(&header->packet_len); 361 if (FRAMED_SIZE(packet_len) > NC_MAX_PACKET) { 362 dev->net->stats.rx_frame_errors++; 363 netdev_dbg(dev->net, "packet too big, %d\n", packet_len); 364 nc_ensure_sync(dev); 365 return 0; 366 } else if (hdr_len < MIN_HEADER) { 367 dev->net->stats.rx_frame_errors++; 368 netdev_dbg(dev->net, "header too short, %d\n", hdr_len); 369 nc_ensure_sync(dev); 370 return 0; 371 } else if (hdr_len > MIN_HEADER) { 372 // out of band data for us? 373 netdev_dbg(dev->net, "header OOB, %d bytes\n", hdr_len - MIN_HEADER); 374 nc_ensure_sync(dev); 375 // switch (vendor/product ids) { ... } 376 } 377 skb_pull(skb, hdr_len); 378 379 trailer = (struct nc_trailer *) 380 (skb->data + skb->len - sizeof *trailer); 381 skb_trim(skb, skb->len - sizeof *trailer); 382 383 if ((packet_len & 0x01) == 0) { 384 if (skb->data [packet_len] != PAD_BYTE) { 385 dev->net->stats.rx_frame_errors++; 386 netdev_dbg(dev->net, "bad pad\n"); 387 return 0; 388 } 389 skb_trim(skb, skb->len - 1); 390 } 391 if (skb->len != packet_len) { 392 dev->net->stats.rx_frame_errors++; 393 netdev_dbg(dev->net, "bad packet len %d (expected %d)\n", 394 skb->len, packet_len); 395 nc_ensure_sync(dev); 396 return 0; 397 } 398 if (header->packet_id != get_unaligned(&trailer->packet_id)) { 399 dev->net->stats.rx_fifo_errors++; 400 netdev_dbg(dev->net, "(2+ dropped) rx packet_id mismatch 0x%x 0x%x\n", 401 le16_to_cpu(header->packet_id), 402 le16_to_cpu(trailer->packet_id)); 403 return 0; 404 } 405 #if 0 406 netdev_dbg(dev->net, "frame <rx h %d p %d id %d\n", header->hdr_len, 407 header->packet_len, header->packet_id); 408 #endif 409 dev->frame_errors = 0; 410 return 1; 411 } 412 413 static struct sk_buff * 414 net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) 415 { 416 struct sk_buff *skb2; 417 struct nc_header *header = NULL; 418 struct nc_trailer *trailer = NULL; 419 int padlen = sizeof (struct nc_trailer); 420 int len = skb->len; 421 422 if (!((len + padlen + sizeof (struct nc_header)) & 0x01)) 423 padlen++; 424 if (!skb_cloned(skb)) { 425 int headroom = skb_headroom(skb); 426 int tailroom = skb_tailroom(skb); 427 428 if (padlen <= tailroom && 429 sizeof(struct nc_header) <= headroom) 430 /* There's enough head and tail room */ 431 goto encapsulate; 432 433 if ((sizeof (struct nc_header) + padlen) < 434 (headroom + tailroom)) { 435 /* There's enough total room, so just readjust */ 436 skb->data = memmove(skb->head 437 + sizeof (struct nc_header), 438 skb->data, skb->len); 439 skb_set_tail_pointer(skb, len); 440 goto encapsulate; 441 } 442 } 443 444 /* Create a new skb to use with the correct size */ 445 skb2 = skb_copy_expand(skb, 446 sizeof (struct nc_header), 447 padlen, 448 flags); 449 dev_kfree_skb_any(skb); 450 if (!skb2) 451 return skb2; 452 skb = skb2; 453 454 encapsulate: 455 /* header first */ 456 header = skb_push(skb, sizeof *header); 457 header->hdr_len = cpu_to_le16(sizeof (*header)); 458 header->packet_len = cpu_to_le16(len); 459 header->packet_id = cpu_to_le16((u16)dev->xid++); 460 461 /* maybe pad; then trailer */ 462 if (!((skb->len + sizeof *trailer) & 0x01)) 463 skb_put_u8(skb, PAD_BYTE); 464 trailer = skb_put(skb, sizeof *trailer); 465 put_unaligned(header->packet_id, &trailer->packet_id); 466 #if 0 467 netdev_dbg(dev->net, "frame >tx h %d p %d id %d\n", 468 header->hdr_len, header->packet_len, 469 header->packet_id); 470 #endif 471 return skb; 472 } 473 474 static int net1080_bind(struct usbnet *dev, struct usb_interface *intf) 475 { 476 unsigned extra = sizeof (struct nc_header) 477 + 1 478 + sizeof (struct nc_trailer); 479 480 dev->net->hard_header_len += extra; 481 dev->rx_urb_size = dev->net->hard_header_len + dev->net->mtu; 482 dev->hard_mtu = NC_MAX_PACKET; 483 return usbnet_get_endpoints (dev, intf); 484 } 485 486 static const struct driver_info net1080_info = { 487 .description = "NetChip TurboCONNECT", 488 .flags = FLAG_POINTTOPOINT | FLAG_FRAMING_NC, 489 .bind = net1080_bind, 490 .reset = net1080_reset, 491 .check_connect = net1080_check_connect, 492 .rx_fixup = net1080_rx_fixup, 493 .tx_fixup = net1080_tx_fixup, 494 }; 495 496 static const struct usb_device_id products [] = { 497 { 498 USB_DEVICE(0x0525, 0x1080), // NetChip ref design 499 .driver_info = (unsigned long) &net1080_info, 500 }, { 501 USB_DEVICE(0x06D0, 0x0622), // Laplink Gold 502 .driver_info = (unsigned long) &net1080_info, 503 }, 504 { }, // END 505 }; 506 MODULE_DEVICE_TABLE(usb, products); 507 508 static struct usb_driver net1080_driver = { 509 .name = "net1080", 510 .id_table = products, 511 .probe = usbnet_probe, 512 .disconnect = usbnet_disconnect, 513 .suspend = usbnet_suspend, 514 .resume = usbnet_resume, 515 .disable_hub_initiated_lpm = 1, 516 }; 517 518 module_usb_driver(net1080_driver); 519 520 MODULE_AUTHOR("David Brownell"); 521 MODULE_DESCRIPTION("NetChip 1080 based USB Host-to-Host Links"); 522 MODULE_LICENSE("GPL"); 523