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                             u16 param1, u16 param2)
  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, param2);
 108         hermes_write_regn(hw, PARAM1, param1);
 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
 126 int hermes_init(hermes_t *hw)
 127 {
 128         u16 status, reg;
 129         int err = 0;
 130         int k;
 131
 132         /* We don't want to be interrupted while resetting the chipset */
 133         hw->inten = 0x0;
 134         hermes_write_regn(hw, INTEN, 0);
 135         hermes_write_regn(hw, EVACK, 0xffff);
 136
 137         /* Normally it's a "can't happen" for the command register to
 138            be busy when we go to issue a command because we are
 139            serializing all commands.  However we want to have some
 140            chance of resetting the card even if it gets into a stupid
 141            state, so we actually wait to see if the command register
 142            will unbusy itself here. */
 143         k = CMD_BUSY_TIMEOUT;
 144         reg = hermes_read_regn(hw, CMD);
 145         while (k && (reg & HERMES_CMD_BUSY)) {
 146                 if (reg == 0xffff) /* Special case - the card has probably been removed,
 147                                       so don't wait for the timeout */
 148                         return -ENODEV;
 149
 150                 k--;
 151                 udelay(1);
 152                 reg = hermes_read_regn(hw, CMD);
 153         }
 154
 155         /* No need to explicitly handle the timeout - if we've timed
 156            out hermes_issue_cmd() will probably return -EBUSY below */
 157
 158         /* According to the documentation, EVSTAT may contain
 159            obsolete event occurrence information.  We have to acknowledge
 160            it by writing EVACK. */
 161         reg = hermes_read_regn(hw, EVSTAT);
 162         hermes_write_regn(hw, EVACK, reg);
 163
 164         /* We don't use hermes_docmd_wait here, because the reset wipes
 165            the magic constant in SWSUPPORT0 away, and it gets confused */
 166         err = hermes_issue_cmd(hw, HERMES_CMD_INIT, 0, 0, 0);
 167         if (err)
 168                 return err;
 169
 170         reg = hermes_read_regn(hw, EVSTAT);
 171         k = CMD_INIT_TIMEOUT;
 172         while ( (! (reg & HERMES_EV_CMD)) && k) {
 173                 k--;
 174                 udelay(10);
 175                 reg = hermes_read_regn(hw, EVSTAT);
 176         }
 177
 178         hermes_write_regn(hw, SWSUPPORT0, HERMES_MAGIC);
 179
 180         if (! hermes_present(hw)) {
 181                 DEBUG(0, "hermes @ 0x%x: Card removed during reset.\n",
 182                        hw->iobase);
 183                 err = -ENODEV;
 184                 goto out;
 185         }
 186
 187         if (! (reg & HERMES_EV_CMD)) {
 188                 printk(KERN_ERR "hermes @ %p: "
 189                        "Timeout waiting for card to reset (reg=0x%04x)!\n",
 190                        hw->iobase, reg);
 191                 err = -ETIMEDOUT;
 192                 goto out;
 193         }
 194
 195         status = hermes_read_regn(hw, STATUS);
 196
 197         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 198
 199         if (status & HERMES_STATUS_RESULT)
 200                 err = -EIO;
 201
 202  out:
 203         return err;
 204 }
 205
 206 /* Issue a command to the chip, and (busy!) wait for it to
 207  * complete.
 208  *
 209  * Returns: < 0 on internal error, 0 on success, > 0 on error returned by the firmware
 210  *
 211  * Callable from any context, but locking is your problem. */
 212 int hermes_docmd_wait(hermes_t *hw, u16 cmd, u16 parm0,
 213                       struct hermes_response *resp)
 214 {
 215         int err;
 216         int k;
 217         u16 reg;
 218         u16 status;
 219
 220         err = hermes_issue_cmd(hw, cmd, parm0, 0, 0);
 221         if (err) {
 222                 if (! hermes_present(hw)) {
 223                         if (net_ratelimit())
 224                                 printk(KERN_WARNING "hermes @ %p: "
 225                                        "Card removed while issuing command "
 226                                        "0x%04x.\n", hw->iobase, cmd);
 227                         err = -ENODEV;
 228                 } else
 229                         if (net_ratelimit())
 230                                 printk(KERN_ERR "hermes @ %p: "
 231                                        "Error %d issuing command 0x%04x.\n",
 232                                        hw->iobase, err, cmd);
 233                 goto out;
 234         }
 235
 236         reg = hermes_read_regn(hw, EVSTAT);
 237         k = CMD_COMPL_TIMEOUT;
 238         while ( (! (reg & HERMES_EV_CMD)) && k) {
 239                 k--;
 240                 udelay(10);
 241                 reg = hermes_read_regn(hw, EVSTAT);
 242         }
 243
 244         if (! hermes_present(hw)) {
 245                 printk(KERN_WARNING "hermes @ %p: Card removed "
 246                        "while waiting for command 0x%04x completion.\n",
 247                        hw->iobase, cmd);
 248                 err = -ENODEV;
 249                 goto out;
 250         }
 251
 252         if (! (reg & HERMES_EV_CMD)) {
 253                 printk(KERN_ERR "hermes @ %p: Timeout waiting for "
 254                        "command 0x%04x completion.\n", hw->iobase, cmd);
 255                 err = -ETIMEDOUT;
 256                 goto out;
 257         }
 258
 259         status = hermes_read_regn(hw, STATUS);
 260         if (resp) {
 261                 resp->status = status;
 262                 resp->resp0 = hermes_read_regn(hw, RESP0);
 263                 resp->resp1 = hermes_read_regn(hw, RESP1);
 264                 resp->resp2 = hermes_read_regn(hw, RESP2);
 265         }
 266
 267         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 268
 269         if (status & HERMES_STATUS_RESULT)
 270                 err = -EIO;
 271
 272  out:
 273         return err;
 274 }
 275
 276 int hermes_allocate(hermes_t *hw, u16 size, u16 *fid)
 277 {
 278         int err = 0;
 279         int k;
 280         u16 reg;
 281
 282         if ( (size < HERMES_ALLOC_LEN_MIN) || (size > HERMES_ALLOC_LEN_MAX) )
 283                 return -EINVAL;
 284
 285         err = hermes_docmd_wait(hw, HERMES_CMD_ALLOC, size, NULL);
 286         if (err) {
 287                 return err;
 288         }
 289
 290         reg = hermes_read_regn(hw, EVSTAT);
 291         k = ALLOC_COMPL_TIMEOUT;
 292         while ( (! (reg & HERMES_EV_ALLOC)) && k) {
 293                 k--;
 294                 udelay(10);
 295                 reg = hermes_read_regn(hw, EVSTAT);
 296         }
 297
 298         if (! hermes_present(hw)) {
 299                 printk(KERN_WARNING "hermes @ %p: "
 300                        "Card removed waiting for frame allocation.\n",
 301                        hw->iobase);
 302                 return -ENODEV;
 303         }
 304
 305         if (! (reg & HERMES_EV_ALLOC)) {
 306                 printk(KERN_ERR "hermes @ %p: "
 307                        "Timeout waiting for frame allocation\n",
 308                        hw->iobase);
 309                 return -ETIMEDOUT;
 310         }
 311
 312         *fid = hermes_read_regn(hw, ALLOCFID);
 313         hermes_write_regn(hw, EVACK, HERMES_EV_ALLOC);
 314
 315         return 0;
 316 }
 317
 318
 319 /* Set up a BAP to read a particular chunk of data from card's internal buffer.
 320  *
 321  * Returns: < 0 on internal failure (errno), 0 on success, >0 on error
 322  * from firmware
 323  *
 324  * Callable from any context */
 325 static int hermes_bap_seek(hermes_t *hw, int bap, u16 id, u16 offset)
 326 {
 327         int sreg = bap ? HERMES_SELECT1 : HERMES_SELECT0;
 328         int oreg = bap ? HERMES_OFFSET1 : HERMES_OFFSET0;
 329         int k;
 330         u16 reg;
 331
 332         /* Paranoia.. */
 333         if ( (offset > HERMES_BAP_OFFSET_MAX) || (offset % 2) )
 334                 return -EINVAL;
 335
 336         k = HERMES_BAP_BUSY_TIMEOUT;
 337         reg = hermes_read_reg(hw, oreg);
 338         while ((reg & HERMES_OFFSET_BUSY) && k) {
 339                 k--;
 340                 udelay(1);
 341                 reg = hermes_read_reg(hw, oreg);
 342         }
 343
 344         if (reg & HERMES_OFFSET_BUSY)
 345                 return -ETIMEDOUT;
 346
 347         /* Now we actually set up the transfer */
 348         hermes_write_reg(hw, sreg, id);
 349         hermes_write_reg(hw, oreg, offset);
 350
 351         /* Wait for the BAP to be ready */
 352         k = HERMES_BAP_BUSY_TIMEOUT;
 353         reg = hermes_read_reg(hw, oreg);
 354         while ( (reg & (HERMES_OFFSET_BUSY | HERMES_OFFSET_ERR)) && k) {
 355                 k--;
 356                 udelay(1);
 357                 reg = hermes_read_reg(hw, oreg);
 358         }
 359
 360         if (reg != offset) {
 361                 printk(KERN_ERR "hermes @ %p: BAP%d offset %s: "
 362                        "reg=0x%x id=0x%x offset=0x%x\n", hw->iobase, bap,
 363                        (reg & HERMES_OFFSET_BUSY) ? "timeout" : "error",
 364                        reg, id, offset);
 365
 366                 if (reg & HERMES_OFFSET_BUSY) {
 367                         return -ETIMEDOUT;
 368                 }
 369
 370                 return -EIO;            /* error or wrong offset */
 371         }
 372
 373         return 0;
 374 }
 375
 376 /* Read a block of data from the chip's buffer, via the
 377  * BAP. Synchronization/serialization is the caller's problem.  len
 378  * must be even.
 379  *
 380  * Returns: < 0 on internal failure (errno), 0 on success, > 0 on error from firmware
 381  */
 382 int hermes_bap_pread(hermes_t *hw, int bap, void *buf, int len,
 383                      u16 id, u16 offset)
 384 {
 385         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 386         int err = 0;
 387
 388         if ( (len < 0) || (len % 2) )
 389                 return -EINVAL;
 390
 391         err = hermes_bap_seek(hw, bap, id, offset);
 392         if (err)
 393                 goto out;
 394
 395         /* Actually do the transfer */
 396         hermes_read_words(hw, dreg, buf, len/2);
 397
 398  out:
 399         return err;
 400 }
 401
 402 /* Write a block of data to the chip's buffer, via the
 403  * BAP. Synchronization/serialization is the caller's problem.
 404  *
 405  * Returns: < 0 on internal failure (errno), 0 on success, > 0 on error from firmware
 406  */
 407 int hermes_bap_pwrite(hermes_t *hw, int bap, const void *buf, int len,
 408                       u16 id, u16 offset)
 409 {
 410         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 411         int err = 0;
 412
 413         if (len < 0)
 414                 return -EINVAL;
 415
 416         err = hermes_bap_seek(hw, bap, id, offset);
 417         if (err)
 418                 goto out;
 419
 420         /* Actually do the transfer */
 421         hermes_write_bytes(hw, dreg, buf, len);
 422
 423  out:
 424         return err;
 425 }
 426
 427 /* Read a Length-Type-Value record from the card.
 428  *
 429  * If length is NULL, we ignore the length read from the card, and
 430  * read the entire buffer regardless. This is useful because some of
 431  * the configuration records appear to have incorrect lengths in
 432  * practice.
 433  *
 434  * Callable from user or bh context.  */
 435 int hermes_read_ltv(hermes_t *hw, int bap, u16 rid, unsigned bufsize,
 436                     u16 *length, void *buf)
 437 {
 438         int err = 0;
 439         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 440         u16 rlength, rtype;
 441         unsigned nwords;
 442
 443         if ( (bufsize < 0) || (bufsize % 2) )
 444                 return -EINVAL;
 445
 446         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS, rid, NULL);
 447         if (err)
 448                 return err;
 449
 450         err = hermes_bap_seek(hw, bap, rid, 0);
 451         if (err)
 452                 return err;
 453
 454         rlength = hermes_read_reg(hw, dreg);
 455
 456         if (! rlength)
 457                 return -ENODATA;
 458
 459         rtype = hermes_read_reg(hw, dreg);
 460
 461         if (length)
 462                 *length = rlength;
 463
 464         if (rtype != rid)
 465                 printk(KERN_WARNING "hermes @ %p: %s(): "
 466                        "rid (0x%04x) does not match type (0x%04x)\n",
 467                        hw->iobase, __func__, rid, rtype);
 468         if (HERMES_RECLEN_TO_BYTES(rlength) > bufsize)
 469                 printk(KERN_WARNING "hermes @ %p: "
 470                        "Truncating LTV record from %d to %d bytes. "
 471                        "(rid=0x%04x, len=0x%04x)\n", hw->iobase,
 472                        HERMES_RECLEN_TO_BYTES(rlength), bufsize, rid, rlength);
 473
 474         nwords = min((unsigned)rlength - 1, bufsize / 2);
 475         hermes_read_words(hw, dreg, buf, nwords);
 476
 477         return 0;
 478 }
 479
 480 int hermes_write_ltv(hermes_t *hw, int bap, u16 rid,
 481                      u16 length, const void *value)
 482 {
 483         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 484         int err = 0;
 485         unsigned count;
 486
 487         if (length == 0)
 488                 return -EINVAL;
 489
 490         err = hermes_bap_seek(hw, bap, rid, 0);
 491         if (err)
 492                 return err;
 493
 494         hermes_write_reg(hw, dreg, length);
 495         hermes_write_reg(hw, dreg, rid);
 496
 497         count = length - 1;
 498
 499         hermes_write_bytes(hw, dreg, value, count << 1);
 500
 501         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS | HERMES_CMD_WRITE,
 502                                 rid, NULL);
 503
 504         return err;
 505 }
 506
 507 EXPORT_SYMBOL(hermes_struct_init);
 508 EXPORT_SYMBOL(hermes_init);
 509 EXPORT_SYMBOL(hermes_docmd_wait);
 510 EXPORT_SYMBOL(hermes_allocate);
 511
 512 EXPORT_SYMBOL(hermes_bap_pread);
 513 EXPORT_SYMBOL(hermes_bap_pwrite);
 514 EXPORT_SYMBOL(hermes_read_ltv);
 515 EXPORT_SYMBOL(hermes_write_ltv);
 516
 517 static int __init init_hermes(void)
 518 {
 519         return 0;
 520 }
 521
 522 static void __exit exit_hermes(void)
 523 {
 524 }
 525
 526 module_init(init_hermes);
 527 module_exit(exit_hermes);