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