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