drivers/net/wireless/orinoco/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 /* These are maximum timeouts. Most often, card wil react much faster */
  49 #define CMD_BUSY_TIMEOUT (100) /* In iterations of ~1us */
  50 #define CMD_INIT_TIMEOUT (50000) /* in iterations of ~10us */
  51 #define CMD_COMPL_TIMEOUT (20000) /* in iterations of ~10us */
  52 #define ALLOC_COMPL_TIMEOUT (1000) /* in iterations of ~10us */
  53
  54 /*
  55  * Debugging helpers
  56  */
  57
  58 #define DMSG(stuff...) do {printk(KERN_DEBUG "hermes @ %p: " , hw->iobase); \
  59                         printk(stuff); } while (0)
  60
  61 #undef HERMES_DEBUG
  62 #ifdef HERMES_DEBUG
  63 #include <stdarg.h>
  64
  65 #define DEBUG(lvl, stuff...) if ((lvl) <= HERMES_DEBUG) DMSG(stuff)
  66
  67 #else /* ! HERMES_DEBUG */
  68
  69 #define DEBUG(lvl, stuff...) do { } while (0)
  70
  71 #endif /* ! HERMES_DEBUG */
  72
  73
  74 /*
  75  * Internal functions
  76  */
  77
  78 /* Issue a command to the chip. Waiting for it to complete is the caller's
  79    problem.
  80
  81    Returns -EBUSY if the command register is busy, 0 on success.
  82
  83    Callable from any context.
  84 */
  85 static int hermes_issue_cmd(hermes_t *hw, u16 cmd, u16 param0,
  86                             u16 param1, u16 param2)
  87 {
  88         int k = CMD_BUSY_TIMEOUT;
  89         u16 reg;
  90
  91         /* First wait for the command register to unbusy */
  92         reg = hermes_read_regn(hw, CMD);
  93         while ((reg & HERMES_CMD_BUSY) && k) {
  94                 k--;
  95                 udelay(1);
  96                 reg = hermes_read_regn(hw, CMD);
  97         }
  98         if (reg & HERMES_CMD_BUSY)
  99                 return -EBUSY;
 100
 101         hermes_write_regn(hw, PARAM2, param2);
 102         hermes_write_regn(hw, PARAM1, param1);
 103         hermes_write_regn(hw, PARAM0, param0);
 104         hermes_write_regn(hw, CMD, cmd);
 105
 106         return 0;
 107 }
 108
 109 /*
 110  * Function definitions
 111  */
 112
 113 /* For doing cmds that wipe the magic constant in SWSUPPORT0 */
 114 int hermes_doicmd_wait(hermes_t *hw, u16 cmd,
 115                        u16 parm0, u16 parm1, u16 parm2,
 116                        struct hermes_response *resp)
 117 {
 118         int err = 0;
 119         int k;
 120         u16 status, reg;
 121
 122         err = hermes_issue_cmd(hw, cmd, parm0, parm1, parm2);
 123         if (err)
 124                 return err;
 125
 126         reg = hermes_read_regn(hw, EVSTAT);
 127         k = CMD_INIT_TIMEOUT;
 128         while ((!(reg & HERMES_EV_CMD)) && k) {
 129                 k--;
 130                 udelay(10);
 131                 reg = hermes_read_regn(hw, EVSTAT);
 132         }
 133
 134         hermes_write_regn(hw, SWSUPPORT0, HERMES_MAGIC);
 135
 136         if (!hermes_present(hw)) {
 137                 DEBUG(0, "hermes @ 0x%x: Card removed during reset.\n",
 138                        hw->iobase);
 139                 err = -ENODEV;
 140                 goto out;
 141         }
 142
 143         if (!(reg & HERMES_EV_CMD)) {
 144                 printk(KERN_ERR "hermes @ %p: "
 145                        "Timeout waiting for card to reset (reg=0x%04x)!\n",
 146                        hw->iobase, reg);
 147                 err = -ETIMEDOUT;
 148                 goto out;
 149         }
 150
 151         status = hermes_read_regn(hw, STATUS);
 152         if (resp) {
 153                 resp->status = status;
 154                 resp->resp0 = hermes_read_regn(hw, RESP0);
 155                 resp->resp1 = hermes_read_regn(hw, RESP1);
 156                 resp->resp2 = hermes_read_regn(hw, RESP2);
 157         }
 158
 159         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 160
 161         if (status & HERMES_STATUS_RESULT)
 162                 err = -EIO;
 163 out:
 164         return err;
 165 }
 166 EXPORT_SYMBOL(hermes_doicmd_wait);
 167
 168 void hermes_struct_init(hermes_t *hw, void __iomem *address, int reg_spacing)
 169 {
 170         hw->iobase = address;
 171         hw->reg_spacing = reg_spacing;
 172         hw->inten = 0x0;
 173 }
 174 EXPORT_SYMBOL(hermes_struct_init);
 175
 176 int hermes_init(hermes_t *hw)
 177 {
 178         u16 reg;
 179         int err = 0;
 180         int k;
 181
 182         /* We don't want to be interrupted while resetting the chipset */
 183         hw->inten = 0x0;
 184         hermes_write_regn(hw, INTEN, 0);
 185         hermes_write_regn(hw, EVACK, 0xffff);
 186
 187         /* Normally it's a "can't happen" for the command register to
 188            be busy when we go to issue a command because we are
 189            serializing all commands.  However we want to have some
 190            chance of resetting the card even if it gets into a stupid
 191            state, so we actually wait to see if the command register
 192            will unbusy itself here. */
 193         k = CMD_BUSY_TIMEOUT;
 194         reg = hermes_read_regn(hw, CMD);
 195         while (k && (reg & HERMES_CMD_BUSY)) {
 196                 if (reg == 0xffff) /* Special case - the card has probably been
 197                                       removed, so don't wait for the timeout */
 198                         return -ENODEV;
 199
 200                 k--;
 201                 udelay(1);
 202                 reg = hermes_read_regn(hw, CMD);
 203         }
 204
 205         /* No need to explicitly handle the timeout - if we've timed
 206            out hermes_issue_cmd() will probably return -EBUSY below */
 207
 208         /* According to the documentation, EVSTAT may contain
 209            obsolete event occurrence information.  We have to acknowledge
 210            it by writing EVACK. */
 211         reg = hermes_read_regn(hw, EVSTAT);
 212         hermes_write_regn(hw, EVACK, reg);
 213
 214         /* We don't use hermes_docmd_wait here, because the reset wipes
 215            the magic constant in SWSUPPORT0 away, and it gets confused */
 216         err = hermes_doicmd_wait(hw, HERMES_CMD_INIT, 0, 0, 0, NULL);
 217
 218         return err;
 219 }
 220 EXPORT_SYMBOL(hermes_init);
 221
 222 /* Issue a command to the chip, and (busy!) wait for it to
 223  * complete.
 224  *
 225  * Returns:
 226  *     < 0 on internal error
 227  *       0 on success
 228  *     > 0 on error returned by the firmware
 229  *
 230  * Callable from any context, but locking is your problem. */
 231 int hermes_docmd_wait(hermes_t *hw, u16 cmd, u16 parm0,
 232                       struct hermes_response *resp)
 233 {
 234         int err;
 235         int k;
 236         u16 reg;
 237         u16 status;
 238
 239         err = hermes_issue_cmd(hw, cmd, parm0, 0, 0);
 240         if (err) {
 241                 if (!hermes_present(hw)) {
 242                         if (net_ratelimit())
 243                                 printk(KERN_WARNING "hermes @ %p: "
 244                                        "Card removed while issuing command "
 245                                        "0x%04x.\n", hw->iobase, cmd);
 246                         err = -ENODEV;
 247                 } else
 248                         if (net_ratelimit())
 249                                 printk(KERN_ERR "hermes @ %p: "
 250                                        "Error %d issuing command 0x%04x.\n",
 251                                        hw->iobase, err, cmd);
 252                 goto out;
 253         }
 254
 255         reg = hermes_read_regn(hw, EVSTAT);
 256         k = CMD_COMPL_TIMEOUT;
 257         while ((!(reg & HERMES_EV_CMD)) && k) {
 258                 k--;
 259                 udelay(10);
 260                 reg = hermes_read_regn(hw, EVSTAT);
 261         }
 262
 263         if (!hermes_present(hw)) {
 264                 printk(KERN_WARNING "hermes @ %p: Card removed "
 265                        "while waiting for command 0x%04x completion.\n",
 266                        hw->iobase, cmd);
 267                 err = -ENODEV;
 268                 goto out;
 269         }
 270
 271         if (!(reg & HERMES_EV_CMD)) {
 272                 printk(KERN_ERR "hermes @ %p: Timeout waiting for "
 273                        "command 0x%04x completion.\n", hw->iobase, cmd);
 274                 err = -ETIMEDOUT;
 275                 goto out;
 276         }
 277
 278         status = hermes_read_regn(hw, STATUS);
 279         if (resp) {
 280                 resp->status = status;
 281                 resp->resp0 = hermes_read_regn(hw, RESP0);
 282                 resp->resp1 = hermes_read_regn(hw, RESP1);
 283                 resp->resp2 = hermes_read_regn(hw, RESP2);
 284         }
 285
 286         hermes_write_regn(hw, EVACK, HERMES_EV_CMD);
 287
 288         if (status & HERMES_STATUS_RESULT)
 289                 err = -EIO;
 290
 291  out:
 292         return err;
 293 }
 294 EXPORT_SYMBOL(hermes_docmd_wait);
 295
 296 int hermes_allocate(hermes_t *hw, u16 size, u16 *fid)
 297 {
 298         int err = 0;
 299         int k;
 300         u16 reg;
 301
 302         if ((size < HERMES_ALLOC_LEN_MIN) || (size > HERMES_ALLOC_LEN_MAX))
 303                 return -EINVAL;
 304
 305         err = hermes_docmd_wait(hw, HERMES_CMD_ALLOC, size, NULL);
 306         if (err)
 307                 return err;
 308
 309         reg = hermes_read_regn(hw, EVSTAT);
 310         k = ALLOC_COMPL_TIMEOUT;
 311         while ((!(reg & HERMES_EV_ALLOC)) && k) {
 312                 k--;
 313                 udelay(10);
 314                 reg = hermes_read_regn(hw, EVSTAT);
 315         }
 316
 317         if (!hermes_present(hw)) {
 318                 printk(KERN_WARNING "hermes @ %p: "
 319                        "Card removed waiting for frame allocation.\n",
 320                        hw->iobase);
 321                 return -ENODEV;
 322         }
 323
 324         if (!(reg & HERMES_EV_ALLOC)) {
 325                 printk(KERN_ERR "hermes @ %p: "
 326                        "Timeout waiting for frame allocation\n",
 327                        hw->iobase);
 328                 return -ETIMEDOUT;
 329         }
 330
 331         *fid = hermes_read_regn(hw, ALLOCFID);
 332         hermes_write_regn(hw, EVACK, HERMES_EV_ALLOC);
 333
 334         return 0;
 335 }
 336 EXPORT_SYMBOL(hermes_allocate);
 337
 338 /* Set up a BAP to read a particular chunk of data from card's internal buffer.
 339  *
 340  * Returns:
 341  *     < 0 on internal failure (errno)
 342  *       0 on success
 343  *     > 0 on error
 344  * from firmware
 345  *
 346  * Callable from any context */
 347 static int hermes_bap_seek(hermes_t *hw, int bap, u16 id, u16 offset)
 348 {
 349         int sreg = bap ? HERMES_SELECT1 : HERMES_SELECT0;
 350         int oreg = bap ? HERMES_OFFSET1 : HERMES_OFFSET0;
 351         int k;
 352         u16 reg;
 353
 354         /* Paranoia.. */
 355         if ((offset > HERMES_BAP_OFFSET_MAX) || (offset % 2))
 356                 return -EINVAL;
 357
 358         k = HERMES_BAP_BUSY_TIMEOUT;
 359         reg = hermes_read_reg(hw, oreg);
 360         while ((reg & HERMES_OFFSET_BUSY) && k) {
 361                 k--;
 362                 udelay(1);
 363                 reg = hermes_read_reg(hw, oreg);
 364         }
 365
 366         if (reg & HERMES_OFFSET_BUSY)
 367                 return -ETIMEDOUT;
 368
 369         /* Now we actually set up the transfer */
 370         hermes_write_reg(hw, sreg, id);
 371         hermes_write_reg(hw, oreg, offset);
 372
 373         /* Wait for the BAP to be ready */
 374         k = HERMES_BAP_BUSY_TIMEOUT;
 375         reg = hermes_read_reg(hw, oreg);
 376         while ((reg & (HERMES_OFFSET_BUSY | HERMES_OFFSET_ERR)) && k) {
 377                 k--;
 378                 udelay(1);
 379                 reg = hermes_read_reg(hw, oreg);
 380         }
 381
 382         if (reg != offset) {
 383                 printk(KERN_ERR "hermes @ %p: BAP%d offset %s: "
 384                        "reg=0x%x id=0x%x offset=0x%x\n", hw->iobase, bap,
 385                        (reg & HERMES_OFFSET_BUSY) ? "timeout" : "error",
 386                        reg, id, offset);
 387
 388                 if (reg & HERMES_OFFSET_BUSY)
 389                         return -ETIMEDOUT;
 390
 391                 return -EIO;            /* error or wrong offset */
 392         }
 393
 394         return 0;
 395 }
 396
 397 /* Read a block of data from the chip's buffer, via the
 398  * BAP. Synchronization/serialization is the caller's problem.  len
 399  * must be even.
 400  *
 401  * Returns:
 402  *     < 0 on internal failure (errno)
 403  *       0 on success
 404  *     > 0 on error from firmware
 405  */
 406 int hermes_bap_pread(hermes_t *hw, int bap, 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) || (len % 2))
 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_read_words(hw, dreg, buf, len/2);
 421
 422  out:
 423         return err;
 424 }
 425 EXPORT_SYMBOL(hermes_bap_pread);
 426
 427 /* Write a block of data to the chip's buffer, via the
 428  * BAP. Synchronization/serialization is the caller's problem.
 429  *
 430  * Returns:
 431  *     < 0 on internal failure (errno)
 432  *       0 on success
 433  *     > 0 on error from firmware
 434  */
 435 int hermes_bap_pwrite(hermes_t *hw, int bap, const void *buf, int len,
 436                       u16 id, u16 offset)
 437 {
 438         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 439         int err = 0;
 440
 441         if (len < 0)
 442                 return -EINVAL;
 443
 444         err = hermes_bap_seek(hw, bap, id, offset);
 445         if (err)
 446                 goto out;
 447
 448         /* Actually do the transfer */
 449         hermes_write_bytes(hw, dreg, buf, len);
 450
 451  out:
 452         return err;
 453 }
 454 EXPORT_SYMBOL(hermes_bap_pwrite);
 455
 456 /* Read a Length-Type-Value record from the card.
 457  *
 458  * If length is NULL, we ignore the length read from the card, and
 459  * read the entire buffer regardless. This is useful because some of
 460  * the configuration records appear to have incorrect lengths in
 461  * practice.
 462  *
 463  * Callable from user or bh context.  */
 464 int hermes_read_ltv(hermes_t *hw, int bap, u16 rid, unsigned bufsize,
 465                     u16 *length, void *buf)
 466 {
 467         int err = 0;
 468         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 469         u16 rlength, rtype;
 470         unsigned nwords;
 471
 472         if (bufsize % 2)
 473                 return -EINVAL;
 474
 475         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS, rid, NULL);
 476         if (err)
 477                 return err;
 478
 479         err = hermes_bap_seek(hw, bap, rid, 0);
 480         if (err)
 481                 return err;
 482
 483         rlength = hermes_read_reg(hw, dreg);
 484
 485         if (!rlength)
 486                 return -ENODATA;
 487
 488         rtype = hermes_read_reg(hw, dreg);
 489
 490         if (length)
 491                 *length = rlength;
 492
 493         if (rtype != rid)
 494                 printk(KERN_WARNING "hermes @ %p: %s(): "
 495                        "rid (0x%04x) does not match type (0x%04x)\n",
 496                        hw->iobase, __func__, rid, rtype);
 497         if (HERMES_RECLEN_TO_BYTES(rlength) > bufsize)
 498                 printk(KERN_WARNING "hermes @ %p: "
 499                        "Truncating LTV record from %d to %d bytes. "
 500                        "(rid=0x%04x, len=0x%04x)\n", hw->iobase,
 501                        HERMES_RECLEN_TO_BYTES(rlength), bufsize, rid, rlength);
 502
 503         nwords = min((unsigned)rlength - 1, bufsize / 2);
 504         hermes_read_words(hw, dreg, buf, nwords);
 505
 506         return 0;
 507 }
 508 EXPORT_SYMBOL(hermes_read_ltv);
 509
 510 int hermes_write_ltv(hermes_t *hw, int bap, u16 rid,
 511                      u16 length, const void *value)
 512 {
 513         int dreg = bap ? HERMES_DATA1 : HERMES_DATA0;
 514         int err = 0;
 515         unsigned count;
 516
 517         if (length == 0)
 518                 return -EINVAL;
 519
 520         err = hermes_bap_seek(hw, bap, rid, 0);
 521         if (err)
 522                 return err;
 523
 524         hermes_write_reg(hw, dreg, length);
 525         hermes_write_reg(hw, dreg, rid);
 526
 527         count = length - 1;
 528
 529         hermes_write_bytes(hw, dreg, value, count << 1);
 530
 531         err = hermes_docmd_wait(hw, HERMES_CMD_ACCESS | HERMES_CMD_WRITE,
 532                                 rid, NULL);
 533
 534         return err;
 535 }
 536 EXPORT_SYMBOL(hermes_write_ltv);