drivers/net/wireless/hermes.c

   1 /* hermes.c
   2  *
   3  * Driver core for the "Hermes" wireless MAC controller, as used in
   4  * the Lucent Orinoco and Cabletron RoamAbout cards. It should also
   5  * work on the hfa3841 and hfa3842 MAC controller chips used in the
   6  * Prism II chipsets.
   7  *
   8  * This is not a complete driver, just low-level access routines for
   9  * the MAC controller itself.
  10  *
  11  * Based on the prism2 driver from Absolute Value Systems' linux-wlan
  12  * project, the Linux wvlan_cs driver, Lucent's HCF-Light
  13  * (wvlan_hcf.c) library, and the NetBSD wireless driver (in no
  14  * particular order).
  15  *
  16  * Copyright (C) 2000, David Gibson, Linuxcare Australia.
  17  * (C) Copyright David Gibson, IBM Corp. 2001-2003.
  18  *
  19  * The contents of this file are subject to the Mozilla Public License
  20  * Version 1.1 (the "License"); you may not use this file except in
  21  * compliance with the License. You may obtain a copy of the License
  22  * at http://www.mozilla.org/MPL/
  23  *
  24  * Software distributed under the License is distributed on an "AS IS"
  25  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  26  * the License for the specific language governing rights and
  27  * limitations under the License.
  28  *
  29  * Alternatively, the contents of this file may be used under the
  30  * terms of the GNU General Public License version 2 (the "GPL"), in
  31  * which case the provisions of the GPL are applicable instead of the
  32  * above.  If you wish to allow the use of your version of this file
  33  * only under the terms of the GPL and not to allow others to use your
  34  * version of this file under the MPL, indicate your decision by
  35  * deleting the provisions above and replace them with the notice and
  36  * other provisions required by the GPL.  If you do not delete the
  37  * provisions above, a recipient may use your version of this file
  38  * under either the MPL or the GPL.
  39  */
  40
  41 #include <linux/config.h>
  42
  43 #include <linux/module.h>
  44 #include <linux/types.h>
  45 #include <linux/threads.h>
  46 #include <linux/smp.h>
  47 #include <asm/io.h>
  48 #include <linux/delay.h>
  49 #include <linux/init.h>
  50 #include <linux/kernel.h>
  51 #include <linux/net.h>
  52 #include <asm/errno.h>
  53
  54 #include "hermes.h"
  55
  56 MODULE_DESCRIPTION("Low-level driver helper for Lucent Hermes chipset and Prism II HFA384x wireless MAC controller");
  57 MODULE_AUTHOR("Pavel Roskin <proski@gnu.org>"
  58         " & David Gibson <hermes@gibson.dropbear.id.au>");
  59 MODULE_LICENSE("Dual MPL/GPL");
  60
  61 /* These are maximum timeouts. Most often, card wil react much faster */
  62 #define CMD_BUSY_TIMEOUT (100) /* In iterations of ~1us */
  63 #define CMD_INIT_TIMEOUT (50000) /* in iterations of ~10us */
  64 #define CMD_COMPL_TIMEOUT (20000) /* in iterations of ~10us */
  65 #define ALLOC_COMPL_TIMEOUT (1000) /* in iterations of ~10us */
  66
  67 /*
  68  * Debugging helpers
  69  */
  70
  71 #define DMSG(stuff...) do {printk(KERN_DEBUG "hermes @ %p: " , hw->iobase); \
  72                         printk(stuff);} while (0)
  73
  74 #undef HERMES_DEBUG
  75 #ifdef HERMES_DEBUG
  76 #include <stdarg.h>
  77
  78 #define DEBUG(lvl, stuff...) if ( (lvl) <= HERMES_DEBUG) DMSG(stuff)
  79
  80 #else /* ! HERMES_DEBUG */
  81
  82 #define DEBUG(lvl, stuff...) do { } while (0)
  83
  84 #endif /* ! HERMES_DEBUG */
  85
  86
  87 /*
  88  * Internal functions
  89  */
  90
  91 /* Issue a command to the chip. Waiting for it to complete is the caller's
  92    problem.
  93
  94    Returns -EBUSY if the command register is busy, 0 on success.
  95
  96    Callable from any context.
  97 */
  98 static int hermes_issue_cmd(hermes_t *hw, u16 cmd, u16 param0)
  99 {
 100         int k = CMD_BUSY_TIMEOUT;
 101         u16 reg;
 102
 103         /* First wait for the command register to unbusy */
 104         reg = hermes_read_regn(hw, CMD);
 105         while ( (reg & HERMES_CMD_BUSY) && k ) {
 106                 k--;
 107                 udelay(1);
 108                 reg = hermes_read_regn(hw, CMD);
 109         }
 110         if (reg & HERMES_CMD_BUSY) {
 111                 return -EBUSY;
 112         }
 113
 114         hermes_write_regn(hw, PARAM2, 0);
 115         hermes_write_regn(hw, PARAM1, 0);
 116         hermes_write_regn(hw, PARAM0, param0);
 117         hermes_write_regn(hw, CMD, cmd);
 118
 119         return 0;
 120 }
 121
 122 /*
 123  * Function definitions
 124  */
 125
 126 void hermes_struct_init(hermes_t *hw, void __iomem *address, int reg_spacing)
 127 {
 128         hw->iobase = address;
 129         hw->reg_spacing = reg_spacing;
 130         hw->inten = 0x0;
 131
 132 #ifdef HERMES_DEBUG_BUFFER
 133         hw->dbufp = 0;
 134         memset(&hw->dbuf, 0xff, sizeof(hw->dbuf));
 135         memset(&hw->profile, 0, sizeof(hw->profile));
 136 #endif
 137 }
 138
 139 int hermes_init(hermes_t *hw)
 140 {
 141         u16 status, reg;
 142         int err = 0;
 143         int k;
 144
 145         /* We don't want to be interrupted while resetting the chipset */
 146         hw->inten = 0x0;
 147         hermes_write_regn(hw, INTEN, 0);
 148         hermes_write_regn(hw, EVACK, 0xffff);
 149
 150         /* Normally it's a "can't happen" for the command register to
 151            be busy when we go to issue a command because we are
 152            serializing all commands.  However we want to have some
 153            chance of resetting the card even if it gets into a stupid
 154            state, so we actually wait to see if the command register
 155            will unbusy itself here. */
 156         k = CMD_BUSY_TIMEOUT;
 157         reg = hermes_read_regn(hw, CMD);
 158         while (k && (reg & HERMES_CMD_BUSY)) {
 159                 if (reg == 0xffff) /* Special case - the card has probably been removed,
 160                                       so don't wait for the timeout */
 161                         return -ENODEV;
 162
 163                 k--;
 164                 udelay(1);
 165                 reg = hermes_read_regn(hw, CMD);
 166         }
 167
 168         /* No need to explicitly handle the timeout - if we've timed
 169            out hermes_issue_cmd() will probably return -EBUSY below */
 170
 171         /* According to the documentation, EVSTAT may contain
 172            obsolete event occurrence information.  We have to acknowledge
 173            it by writing EVACK. */
 174         reg = hermes_read_regn(hw, EVSTAT);
 175         hermes_write_regn(hw, EVACK, reg);
 176
 177         /* We don't use hermes_docmd_wait here, because the reset wipes
 178            the magic constant in SWSUPPORT0 away, and it gets confused */
 179         err = hermes_issue_cmd(hw, HERMES_CMD_INIT, 0);
 180         if (err)
 181                 return err;
 182
 183         reg = hermes_read_regn(hw, EVSTAT);
 184         k = CMD_INIT_TIMEOUT;
 185         while ( (! (reg & HERMES_EV_CMD)) && k) {
 186                 k--;
 187                 udelay(10);
 188                 reg = hermes_read_regn(hw, EVSTAT);
 189         }
 190
 191         hermes_write_regn(hw, SWSUPPORT0, HERMES_MAGIC);
 192
 193         if (! hermes_present(hw)) {
 194                 DEBUG(0, "hermes @ 0x%x: Card removed during reset.\n",
 195                        hw->iobase);
 196                 err = -ENODEV;
 197                 goto out;
 198         }
 199
 200         if (! (reg & HERMES_EV_CMD)) {
 201                 printk(KERN_ERR "hermes @ %p: "
 202                        "Timeout waiting for card to reset (reg=0x%04x)!\n",
 203                        hw->iobase, reg);
 204                 err = -ETIMEDOUT;
 205                 goto out;
 206         }
 207
 208         status = hermes_read_regn(hw, STATUS);
 209
 210         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 211
 212         if (status & HERMES_STATUS_RESULT)
 213                 err = -EIO;
 214
 215  out:
 216         return err;
 217 }
 218
 219 /* Issue a command to the chip, and (busy!) wait for it to
 220  * complete.
 221  *
 222  * Returns: < 0 on internal error, 0 on success, > 0 on error returned by the firmware
 223  *
 224  * Callable from any context, but locking is your problem. */
 225 int hermes_docmd_wait(hermes_t *hw, u16 cmd, u16 parm0,
 226                       struct hermes_response *resp)
 227 {
 228         int err;
 229         int k;
 230         u16 reg;
 231         u16 status;
 232
 233         err = hermes_issue_cmd(hw, cmd, parm0);
 234         if (err) {
 235                 if (! hermes_present(hw)) {
 236                         if (net_ratelimit())
 237                                 printk(KERN_WARNING "hermes @ %p: "
 238                                        "Card removed while issuing command "
 239                                        "0x%04x.\n", hw->iobase, cmd);
 240                         err = -ENODEV;
 241                 } else
 242                         if (net_ratelimit())
 243                                 printk(KERN_ERR "hermes @ %p: "
 244                                        "Error %d issuing command 0x%04x.\n",
 245                                        hw->iobase, err, cmd);
 246                 goto out;
 247         }
 248
 249         reg = hermes_read_regn(hw, EVSTAT);
 250         k = CMD_COMPL_TIMEOUT;
 251         while ( (! (reg & HERMES_EV_CMD)) && k) {
 252                 k--;
 253                 udelay(10);
 254                 reg = hermes_read_regn(hw, EVSTAT);
 255         }
 256
 257         if (! hermes_present(hw)) {
 258                 printk(KERN_WARNING "hermes @ %p: Card removed "
 259                        "while waiting for command 0x%04x completion.\n",
 260                        hw->iobase, cmd);
 261                 err = -ENODEV;
 262                 goto out;
 263         }
 264
 265         if (! (reg & HERMES_EV_CMD)) {
 266                 printk(KERN_ERR "hermes @ %p: Timeout waiting for "
 267                        "command 0x%04x completion.\n", hw->iobase, cmd);
 268                 err = -ETIMEDOUT;
 269                 goto out;
 270         }
 271
 272         status = hermes_read_regn(hw, STATUS);
 273         if (resp) {
 274                 resp->status = status;
 275                 resp->resp0 = hermes_read_regn(hw, RESP0);
 276                 resp->resp1 = hermes_read_regn(hw, RESP1);
 277                 resp->resp2 = hermes_read_regn(hw, RESP2);
 278         }
 279
 280         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 281
 282         if (status & HERMES_STATUS_RESULT)
 283                 err = -EIO;
 284
 285  out:
 286         return err;
 287 }
 288
 289 int hermes_allocate(hermes_t *hw, u16 size, u16 *fid)
 290 {
 291         int err = 0;
 292         int k;
 293         u16 reg;
 294
 295         if ( (size < HERMES_ALLOC_LEN_MIN) || (size > HERMES_ALLOC_LEN_MAX) )
 296                 return -EINVAL;
 297
 298         err = hermes_docmd_wait(hw, HERMES_CMD_ALLOC, size, NULL);
 299         if (err) {
 300                 return err;
 301         }
 302
 303         reg = hermes_read_regn(hw, EVSTAT);
 304         k = ALLOC_COMPL_TIMEOUT;
 305         while ( (! (reg & HERMES_EV_ALLOC)) && k) {
 306                 k--;
 307                 udelay(10);
 308                 reg = hermes_read_regn(hw, EVSTAT);
 309         }
 310
 311         if (! hermes_present(hw)) {
 312                 printk(KERN_WARNING "hermes @ %p: "
 313                        "Card removed waiting for frame allocation.\n",
 314                        hw->iobase);
 315                 return -ENODEV;
 316         }
 317
 318         if (! (reg & HERMES_EV_ALLOC)) {
 319                 printk(KERN_ERR "hermes @ %p: "
 320                        "Timeout waiting for frame allocation\n",
 321                        hw->iobase);
 322                 return -ETIMEDOUT;
 323         }
 324
 325         *fid = hermes_read_regn(hw, ALLOCFID);
 326         hermes_write_regn(hw, EVACK, HERMES_EV_ALLOC);
 327
 328         return 0;
 329 }
 330
 331
 332 /* Set up a BAP to read a particular chunk of data from card's internal buffer.
 333  *
 334  * Returns: < 0 on internal failure (errno), 0 on success, >0 on error
 335  * from firmware
 336  *
 337  * Callable from any context */
 338 static int hermes_bap_seek(hermes_t *hw, int bap, u16 id, u16 offset)
 339 {
 340         int sreg = bap ? HERMES_SELECT1 : HERMES_SELECT0;
 341         int oreg = bap ? HERMES_OFFSET1 : HERMES_OFFSET0;
 342         int k;
 343         u16 reg;
 344
 345         /* Paranoia.. */
 346         if ( (offset > HERMES_BAP_OFFSET_MAX) || (offset % 2) )
 347                 return -EINVAL;
 348
 349         k = HERMES_BAP_BUSY_TIMEOUT;
 350         reg = hermes_read_reg(hw, oreg);
 351         while ((reg & HERMES_OFFSET_BUSY) && k) {
 352                 k--;
 353                 udelay(1);
 354                 reg = hermes_read_reg(hw, oreg);
 355         }
 356
 357 #ifdef HERMES_DEBUG_BUFFER
 358         hw->profile[HERMES_BAP_BUSY_TIMEOUT - k]++;
 359
 360         if (k < HERMES_BAP_BUSY_TIMEOUT) {
 361                 struct hermes_debug_entry *e =
 362                         &hw->dbuf[(hw->dbufp++) % HERMES_DEBUG_BUFSIZE];
 363                 e->bap = bap;
 364                 e->id = id;
 365                 e->offset = offset;
 366                 e->cycles = HERMES_BAP_BUSY_TIMEOUT - k;
 367         }
 368 #endif
 369
 370         if (reg & HERMES_OFFSET_BUSY)
 371                 return -ETIMEDOUT;
 372
 373         /* Now we actually set up the transfer */
 374         hermes_write_reg(hw, sreg, id);
 375         hermes_write_reg(hw, oreg, offset);
 376
 377         /* Wait for the BAP to be ready */
 378         k = HERMES_BAP_BUSY_TIMEOUT;
 379         reg = hermes_read_reg(hw, oreg);
 380         while ( (reg & (HERMES_OFFSET_BUSY | HERMES_OFFSET_ERR)) && k) {
 381                 k--;
 382                 udelay(1);
 383                 reg = hermes_read_reg(hw, oreg);
 384         }
 385
 386         if (reg != offset) {
 387                 printk(KERN_ERR "hermes @ %p: BAP%d offset %s: "
 388                        "reg=0x%x id=0x%x offset=0x%x\n", hw->iobase, bap,
 389                        (reg & HERMES_OFFSET_BUSY) ? "timeout" : "error",
 390                        reg, id, offset);
 391
 392                 if (reg & HERMES_OFFSET_BUSY) {
 393                         return -ETIMEDOUT;
 394                 }
 395
 396                 return -EIO;            /* error or wrong offset */
 397         }
 398
 399         return 0;
 400 }
 401
 402 /* Read a block of data from the chip's buffer, via the
 403  * BAP. Synchronization/serialization is the caller's problem.  len
 404  * must be even.
 405  *
 406  * Returns: < 0 on internal failure (errno), 0 on success, > 0 on error from firmware
 407  */
 408 int hermes_bap_pread(hermes_t *hw, int bap, void *buf, unsigned len,
 409                      u16 id, u16 offset)
 410 {
 411         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 412         int err = 0;
 413
 414         if ( (len < 0) || (len % 2) )
 415                 return -EINVAL;
 416
 417         err = hermes_bap_seek(hw, bap, id, offset);
 418         if (err)
 419                 goto out;
 420
 421         /* Actually do the transfer */
 422         hermes_read_words(hw, dreg, buf, len/2);
 423
 424  out:
 425         return err;
 426 }
 427
 428 /* Write a block of data to the chip's buffer, via the
 429  * BAP. Synchronization/serialization is the caller's problem. len
 430  * must be even.
 431  *
 432  * Returns: < 0 on internal failure (errno), 0 on success, > 0 on error from firmware
 433  */
 434 int hermes_bap_pwrite(hermes_t *hw, int bap, const void *buf, unsigned len,
 435                       u16 id, u16 offset)
 436 {
 437         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 438         int err = 0;
 439
 440         if ( (len < 0) || (len % 2) )
 441                 return -EINVAL;
 442
 443         err = hermes_bap_seek(hw, bap, id, offset);
 444         if (err)
 445                 goto out;
 446
 447         /* Actually do the transfer */
 448         hermes_write_words(hw, dreg, buf, len/2);
 449
 450  out:
 451         return err;
 452 }
 453
 454 /* Read a Length-Type-Value record from the card.
 455  *
 456  * If length is NULL, we ignore the length read from the card, and
 457  * read the entire buffer regardless. This is useful because some of
 458  * the configuration records appear to have incorrect lengths in
 459  * practice.
 460  *
 461  * Callable from user or bh context.  */
 462 int hermes_read_ltv(hermes_t *hw, int bap, u16 rid, unsigned bufsize,
 463                     u16 *length, void *buf)
 464 {
 465         int err = 0;
 466         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 467         u16 rlength, rtype;
 468         unsigned nwords;
 469
 470         if ( (bufsize < 0) || (bufsize % 2) )
 471                 return -EINVAL;
 472
 473         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS, rid, NULL);
 474         if (err)
 475                 return err;
 476
 477         err = hermes_bap_seek(hw, bap, rid, 0);
 478         if (err)
 479                 return err;
 480
 481         rlength = hermes_read_reg(hw, dreg);
 482
 483         if (! rlength)
 484                 return -ENODATA;
 485
 486         rtype = hermes_read_reg(hw, dreg);
 487
 488         if (length)
 489                 *length = rlength;
 490
 491         if (rtype != rid)
 492                 printk(KERN_WARNING "hermes @ %p: %s(): "
 493                        "rid (0x%04x) does not match type (0x%04x)\n",
 494                        hw->iobase, __FUNCTION__, rid, rtype);
 495         if (HERMES_RECLEN_TO_BYTES(rlength) > bufsize)
 496                 printk(KERN_WARNING "hermes @ %p: "
 497                        "Truncating LTV record from %d to %d bytes. "
 498                        "(rid=0x%04x, len=0x%04x)\n", hw->iobase,
 499                        HERMES_RECLEN_TO_BYTES(rlength), bufsize, rid, rlength);
 500
 501         nwords = min((unsigned)rlength - 1, bufsize / 2);
 502         hermes_read_words(hw, dreg, buf, nwords);
 503
 504         return 0;
 505 }
 506
 507 int hermes_write_ltv(hermes_t *hw, int bap, u16 rid,
 508                      u16 length, const void *value)
 509 {
 510         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 511         int err = 0;
 512         unsigned count;
 513
 514         if (length == 0)
 515                 return -EINVAL;
 516
 517         err = hermes_bap_seek(hw, bap, rid, 0);
 518         if (err)
 519                 return err;
 520
 521         hermes_write_reg(hw, dreg, length);
 522         hermes_write_reg(hw, dreg, rid);
 523
 524         count = length - 1;
 525
 526         hermes_write_words(hw, dreg, value, count);
 527
 528         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS | HERMES_CMD_WRITE,
 529                                 rid, NULL);
 530
 531         return err;
 532 }
 533
 534 EXPORT_SYMBOL(hermes_struct_init);
 535 EXPORT_SYMBOL(hermes_init);
 536 EXPORT_SYMBOL(hermes_docmd_wait);
 537 EXPORT_SYMBOL(hermes_allocate);
 538
 539 EXPORT_SYMBOL(hermes_bap_pread);
 540 EXPORT_SYMBOL(hermes_bap_pwrite);
 541 EXPORT_SYMBOL(hermes_read_ltv);
 542 EXPORT_SYMBOL(hermes_write_ltv);
 543
 544 static int __init init_hermes(void)
 545 {
 546         return 0;
 547 }
 548
 549 static void __exit exit_hermes(void)
 550 {
 551 }
 552
 553 module_init(init_hermes);
 554 module_exit(exit_hermes);