drivers/w1/masters/ds1wm.c

   1 /*
   2  * 1-wire busmaster driver for DS1WM and ASICs with embedded DS1WMs
   3  * such as HP iPAQs (including h5xxx, h2200, and devices with ASIC3
   4  * like hx4700).
   5  *
   6  * Copyright (c) 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
   7  * Copyright (c) 2004-2007, Matt Reimer <mreimer@vpop.net>
   8  *
   9  * Use consistent with the GNU GPL is permitted,
  10  * provided that this copyright notice is
  11  * preserved in its entirety in all copies and derived works.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/pm.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/err.h>
  20 #include <linux/delay.h>
  21 #include <linux/mfd/core.h>
  22 #include <linux/mfd/ds1wm.h>
  23 #include <linux/slab.h>
  24
  25 #include <asm/io.h>
  26
  27 #include "../w1.h"
  28 #include "../w1_int.h"
  29
  30
  31 #define DS1WM_CMD       0x00    /* R/W 4 bits command */
  32 #define DS1WM_DATA      0x01    /* R/W 8 bits, transmit/receive buffer */
  33 #define DS1WM_INT       0x02    /* R/W interrupt status */
  34 #define DS1WM_INT_EN    0x03    /* R/W interrupt enable */
  35 #define DS1WM_CLKDIV    0x04    /* R/W 5 bits of divisor and pre-scale */
  36 #define DS1WM_CNTRL     0x05    /* R/W master control register (not used yet) */
  37
  38 #define DS1WM_CMD_1W_RESET  (1 << 0)    /* force reset on 1-wire bus */
  39 #define DS1WM_CMD_SRA       (1 << 1)    /* enable Search ROM accelerator mode */
  40 #define DS1WM_CMD_DQ_OUTPUT (1 << 2)    /* write only - forces bus low */
  41 #define DS1WM_CMD_DQ_INPUT  (1 << 3)    /* read only - reflects state of bus */
  42 #define DS1WM_CMD_RST       (1 << 5)    /* software reset */
  43 #define DS1WM_CMD_OD        (1 << 7)    /* overdrive */
  44
  45 #define DS1WM_INT_PD        (1 << 0)    /* presence detect */
  46 #define DS1WM_INT_PDR       (1 << 1)    /* presence detect result */
  47 #define DS1WM_INT_TBE       (1 << 2)    /* tx buffer empty */
  48 #define DS1WM_INT_TSRE      (1 << 3)    /* tx shift register empty */
  49 #define DS1WM_INT_RBF       (1 << 4)    /* rx buffer full */
  50 #define DS1WM_INT_RSRF      (1 << 5)    /* rx shift register full */
  51
  52 #define DS1WM_INTEN_EPD     (1 << 0)    /* enable presence detect int */
  53 #define DS1WM_INTEN_IAS     (1 << 1)    /* INTR active state */
  54 #define DS1WM_INTEN_ETBE    (1 << 2)    /* enable tx buffer empty int */
  55 #define DS1WM_INTEN_ETMT    (1 << 3)    /* enable tx shift register empty int */
  56 #define DS1WM_INTEN_ERBF    (1 << 4)    /* enable rx buffer full int */
  57 #define DS1WM_INTEN_ERSRF   (1 << 5)    /* enable rx shift register full int */
  58 #define DS1WM_INTEN_DQO     (1 << 6)    /* enable direct bus driving ops */
  59
  60 #define DS1WM_INTEN_NOT_IAS (~DS1WM_INTEN_IAS)  /* all but INTR active state */
  61
  62 #define DS1WM_TIMEOUT (HZ * 5)
  63
  64 static struct {
  65         unsigned long freq;
  66         unsigned long divisor;
  67 } freq[] = {
  68         {   1000000, 0x80 },
  69         {   2000000, 0x84 },
  70         {   3000000, 0x81 },
  71         {   4000000, 0x88 },
  72         {   5000000, 0x82 },
  73         {   6000000, 0x85 },
  74         {   7000000, 0x83 },
  75         {   8000000, 0x8c },
  76         {  10000000, 0x86 },
  77         {  12000000, 0x89 },
  78         {  14000000, 0x87 },
  79         {  16000000, 0x90 },
  80         {  20000000, 0x8a },
  81         {  24000000, 0x8d },
  82         {  28000000, 0x8b },
  83         {  32000000, 0x94 },
  84         {  40000000, 0x8e },
  85         {  48000000, 0x91 },
  86         {  56000000, 0x8f },
  87         {  64000000, 0x98 },
  88         {  80000000, 0x92 },
  89         {  96000000, 0x95 },
  90         { 112000000, 0x93 },
  91         { 128000000, 0x9c },
  92 /* you can continue this table, consult the OPERATION - CLOCK DIVISOR
  93    section of the ds1wm spec sheet. */
  94 };
  95
  96 struct ds1wm_data {
  97         void     __iomem *map;
  98         int      bus_shift; /* # of shifts to calc register offsets */
  99         struct platform_device *pdev;
 100         const struct mfd_cell   *cell;
 101         int      irq;
 102         int      slave_present;
 103         void     *reset_complete;
 104         void     *read_complete;
 105         void     *write_complete;
 106         int      read_error;
 107         /* last byte received */
 108         u8       read_byte;
 109         /* byte to write that makes all intr disabled, */
 110         /* considering active_state (IAS) (optimization) */
 111         u8       int_en_reg_none;
 112         unsigned int reset_recover_delay; /* see ds1wm.h */
 113 };
 114
 115 static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,
 116                                         u8 val)
 117 {
 118         __raw_writeb(val, ds1wm_data->map + (reg << ds1wm_data->bus_shift));
 119 }
 120
 121 static inline u8 ds1wm_read_register(struct ds1wm_data *ds1wm_data, u32 reg)
 122 {
 123         return __raw_readb(ds1wm_data->map + (reg << ds1wm_data->bus_shift));
 124 }
 125
 126
 127 static irqreturn_t ds1wm_isr(int isr, void *data)
 128 {
 129         struct ds1wm_data *ds1wm_data = data;
 130         u8 intr;
 131         u8 inten = ds1wm_read_register(ds1wm_data, DS1WM_INT_EN);
 132         /* if no bits are set in int enable register (except the IAS)
 133         than go no further, reading the regs below has side effects */
 134         if (!(inten & DS1WM_INTEN_NOT_IAS))
 135                 return IRQ_NONE;
 136
 137         ds1wm_write_register(ds1wm_data,
 138                 DS1WM_INT_EN, ds1wm_data->int_en_reg_none);
 139
 140         /* this read action clears the INTR and certain flags in ds1wm */
 141         intr = ds1wm_read_register(ds1wm_data, DS1WM_INT);
 142
 143         ds1wm_data->slave_present = (intr & DS1WM_INT_PDR) ? 0 : 1;
 144
 145         if ((intr & DS1WM_INT_TSRE) && ds1wm_data->write_complete) {
 146                 inten &= ~DS1WM_INTEN_ETMT;
 147                 complete(ds1wm_data->write_complete);
 148         }
 149         if (intr & DS1WM_INT_RBF) {
 150                 /* this read clears the RBF flag */
 151                 ds1wm_data->read_byte = ds1wm_read_register(ds1wm_data,
 152                 DS1WM_DATA);
 153                 inten &= ~DS1WM_INTEN_ERBF;
 154                 if (ds1wm_data->read_complete)
 155                         complete(ds1wm_data->read_complete);
 156         }
 157         if ((intr & DS1WM_INT_PD) && ds1wm_data->reset_complete) {
 158                 inten &= ~DS1WM_INTEN_EPD;
 159                 complete(ds1wm_data->reset_complete);
 160         }
 161
 162         ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, inten);
 163         return IRQ_HANDLED;
 164 }
 165
 166 static int ds1wm_reset(struct ds1wm_data *ds1wm_data)
 167 {
 168         unsigned long timeleft;
 169         DECLARE_COMPLETION_ONSTACK(reset_done);
 170
 171         ds1wm_data->reset_complete = &reset_done;
 172
 173         /* enable Presence detect only */
 174         ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, DS1WM_INTEN_EPD |
 175         ds1wm_data->int_en_reg_none);
 176
 177         ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_1W_RESET);
 178
 179         timeleft = wait_for_completion_timeout(&reset_done, DS1WM_TIMEOUT);
 180         ds1wm_data->reset_complete = NULL;
 181         if (!timeleft) {
 182                 dev_err(&ds1wm_data->pdev->dev, "reset failed, timed out\n");
 183                 return 1;
 184         }
 185
 186         if (!ds1wm_data->slave_present) {
 187                 dev_dbg(&ds1wm_data->pdev->dev, "reset: no devices found\n");
 188                 return 1;
 189         }
 190
 191         if (ds1wm_data->reset_recover_delay)
 192                 msleep(ds1wm_data->reset_recover_delay);
 193
 194         return 0;
 195 }
 196
 197 static int ds1wm_write(struct ds1wm_data *ds1wm_data, u8 data)
 198 {
 199         unsigned long timeleft;
 200         DECLARE_COMPLETION_ONSTACK(write_done);
 201         ds1wm_data->write_complete = &write_done;
 202
 203         ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
 204         ds1wm_data->int_en_reg_none | DS1WM_INTEN_ETMT);
 205
 206         ds1wm_write_register(ds1wm_data, DS1WM_DATA, data);
 207
 208         timeleft = wait_for_completion_timeout(&write_done, DS1WM_TIMEOUT);
 209
 210         ds1wm_data->write_complete = NULL;
 211         if (!timeleft) {
 212                 dev_err(&ds1wm_data->pdev->dev, "write failed, timed out\n");
 213                 return -ETIMEDOUT;
 214         }
 215
 216         return 0;
 217 }
 218
 219 static u8 ds1wm_read(struct ds1wm_data *ds1wm_data, unsigned char write_data)
 220 {
 221         unsigned long timeleft;
 222         u8 intEnable = DS1WM_INTEN_ERBF | ds1wm_data->int_en_reg_none;
 223         DECLARE_COMPLETION_ONSTACK(read_done);
 224
 225         ds1wm_read_register(ds1wm_data, DS1WM_DATA);
 226
 227         ds1wm_data->read_complete = &read_done;
 228         ds1wm_write_register(ds1wm_data, DS1WM_INT_EN, intEnable);
 229
 230         ds1wm_write_register(ds1wm_data, DS1WM_DATA, write_data);
 231         timeleft = wait_for_completion_timeout(&read_done, DS1WM_TIMEOUT);
 232
 233         ds1wm_data->read_complete = NULL;
 234         if (!timeleft) {
 235                 dev_err(&ds1wm_data->pdev->dev, "read failed, timed out\n");
 236                 ds1wm_data->read_error = -ETIMEDOUT;
 237                 return 0xFF;
 238         }
 239         ds1wm_data->read_error = 0;
 240         return ds1wm_data->read_byte;
 241 }
 242
 243 static int ds1wm_find_divisor(int gclk)
 244 {
 245         int i;
 246
 247         for (i = ARRAY_SIZE(freq)-1; i >= 0; --i)
 248                 if (gclk >= freq[i].freq)
 249                         return freq[i].divisor;
 250
 251         return 0;
 252 }
 253
 254 static void ds1wm_up(struct ds1wm_data *ds1wm_data)
 255 {
 256         int divisor;
 257         struct ds1wm_driver_data *plat = ds1wm_data->pdev->dev.platform_data;
 258
 259         if (ds1wm_data->cell->enable)
 260                 ds1wm_data->cell->enable(ds1wm_data->pdev);
 261
 262         divisor = ds1wm_find_divisor(plat->clock_rate);
 263         dev_dbg(&ds1wm_data->pdev->dev,
 264                 "found divisor 0x%x for clock %d\n", divisor, plat->clock_rate);
 265         if (divisor == 0) {
 266                 dev_err(&ds1wm_data->pdev->dev,
 267                         "no suitable divisor for %dHz clock\n",
 268                         plat->clock_rate);
 269                 return;
 270         }
 271         ds1wm_write_register(ds1wm_data, DS1WM_CLKDIV, divisor);
 272
 273         /* Let the w1 clock stabilize. */
 274         msleep(1);
 275
 276         ds1wm_reset(ds1wm_data);
 277 }
 278
 279 static void ds1wm_down(struct ds1wm_data *ds1wm_data)
 280 {
 281         ds1wm_reset(ds1wm_data);
 282
 283         /* Disable interrupts. */
 284         ds1wm_write_register(ds1wm_data, DS1WM_INT_EN,
 285                 ds1wm_data->int_en_reg_none);
 286
 287         if (ds1wm_data->cell->disable)
 288                 ds1wm_data->cell->disable(ds1wm_data->pdev);
 289 }
 290
 291 /* --------------------------------------------------------------------- */
 292 /* w1 methods */
 293
 294 static u8 ds1wm_read_byte(void *data)
 295 {
 296         struct ds1wm_data *ds1wm_data = data;
 297
 298         return ds1wm_read(ds1wm_data, 0xff);
 299 }
 300
 301 static void ds1wm_write_byte(void *data, u8 byte)
 302 {
 303         struct ds1wm_data *ds1wm_data = data;
 304
 305         ds1wm_write(ds1wm_data, byte);
 306 }
 307
 308 static u8 ds1wm_reset_bus(void *data)
 309 {
 310         struct ds1wm_data *ds1wm_data = data;
 311
 312         ds1wm_reset(ds1wm_data);
 313
 314         return 0;
 315 }
 316
 317 static void ds1wm_search(void *data, struct w1_master *master_dev,
 318                         u8 search_type, w1_slave_found_callback slave_found)
 319 {
 320         struct ds1wm_data *ds1wm_data = data;
 321         int i;
 322         int ms_discrep_bit = -1;
 323         u64 r = 0; /* holds the progress of the search */
 324         u64 r_prime, d;
 325         unsigned slaves_found = 0;
 326         unsigned int pass = 0;
 327
 328         dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
 329         while (true) {
 330                 ++pass;
 331                 if (pass > 100) {
 332                         dev_dbg(&ds1wm_data->pdev->dev,
 333                                 "too many attempts (100), search aborted\n");
 334                         return;
 335                 }
 336
 337                 mutex_lock(&master_dev->bus_mutex);
 338                 if (ds1wm_reset(ds1wm_data)) {
 339                         mutex_unlock(&master_dev->bus_mutex);
 340                         dev_dbg(&ds1wm_data->pdev->dev,
 341                                 "pass: %d reset error (or no slaves)\n", pass);
 342                         break;
 343                 }
 344
 345                 dev_dbg(&ds1wm_data->pdev->dev,
 346                         "pass: %d r : %0#18llx writing SEARCH_ROM\n", pass, r);
 347                 ds1wm_write(ds1wm_data, search_type);
 348                 dev_dbg(&ds1wm_data->pdev->dev,
 349                         "pass: %d entering ASM\n", pass);
 350                 ds1wm_write_register(ds1wm_data, DS1WM_CMD, DS1WM_CMD_SRA);
 351                 dev_dbg(&ds1wm_data->pdev->dev,
 352                         "pass: %d begining nibble loop\n", pass);
 353
 354                 r_prime = 0;
 355                 d = 0;
 356                 /* we work one nibble at a time */
 357                 /* each nibble is interleaved to form a byte */
 358                 for (i = 0; i < 16; i++) {
 359
 360                         unsigned char resp, _r, _r_prime, _d;
 361
 362                         _r = (r >> (4*i)) & 0xf;
 363                         _r = ((_r & 0x1) << 1) |
 364                         ((_r & 0x2) << 2) |
 365                         ((_r & 0x4) << 3) |
 366                         ((_r & 0x8) << 4);
 367
 368                         /* writes _r, then reads back: */
 369                         resp = ds1wm_read(ds1wm_data, _r);
 370
 371                         if (ds1wm_data->read_error) {
 372                                 dev_err(&ds1wm_data->pdev->dev,
 373                                 "pass: %d nibble: %d read error\n", pass, i);
 374                                 break;
 375                         }
 376
 377                         _r_prime = ((resp & 0x02) >> 1) |
 378                         ((resp & 0x08) >> 2) |
 379                         ((resp & 0x20) >> 3) |
 380                         ((resp & 0x80) >> 4);
 381
 382                         _d = ((resp & 0x01) >> 0) |
 383                         ((resp & 0x04) >> 1) |
 384                         ((resp & 0x10) >> 2) |
 385                         ((resp & 0x40) >> 3);
 386
 387                         r_prime |= (unsigned long long) _r_prime << (i * 4);
 388                         d |= (unsigned long long) _d << (i * 4);
 389
 390                 }
 391                 if (ds1wm_data->read_error) {
 392                         mutex_unlock(&master_dev->bus_mutex);
 393                         dev_err(&ds1wm_data->pdev->dev,
 394                                 "pass: %d read error, retrying\n", pass);
 395                         break;
 396                 }
 397                 dev_dbg(&ds1wm_data->pdev->dev,
 398                         "pass: %d r\': %0#18llx d:%0#18llx\n",
 399                         pass, r_prime, d);
 400                 dev_dbg(&ds1wm_data->pdev->dev,
 401                         "pass: %d nibble loop complete, exiting ASM\n", pass);
 402                 ds1wm_write_register(ds1wm_data, DS1WM_CMD, ~DS1WM_CMD_SRA);
 403                 dev_dbg(&ds1wm_data->pdev->dev,
 404                         "pass: %d resetting bus\n", pass);
 405                 ds1wm_reset(ds1wm_data);
 406                 mutex_unlock(&master_dev->bus_mutex);
 407                 if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
 408                         dev_err(&ds1wm_data->pdev->dev,
 409                                 "pass: %d bus error, retrying\n", pass);
 410                         continue; /* start over */
 411                 }
 412
 413
 414                 dev_dbg(&ds1wm_data->pdev->dev,
 415                         "pass: %d found %0#18llx\n", pass, r_prime);
 416                 slave_found(master_dev, r_prime);
 417                 ++slaves_found;
 418                 dev_dbg(&ds1wm_data->pdev->dev,
 419                         "pass: %d complete, preparing next pass\n", pass);
 420
 421                 /* any discrepency found which we already choose the
 422                    '1' branch is now is now irrelevant we reveal the
 423                    next branch with this: */
 424                 d &= ~r;
 425                 /* find last bit set, i.e. the most signif. bit set */
 426                 ms_discrep_bit = fls64(d) - 1;
 427                 dev_dbg(&ds1wm_data->pdev->dev,
 428                         "pass: %d new d:%0#18llx MS discrep bit:%d\n",
 429                         pass, d, ms_discrep_bit);
 430
 431                 /* prev_ms_discrep_bit = ms_discrep_bit;
 432                    prepare for next ROM search:             */
 433                 if (ms_discrep_bit == -1)
 434                         break;
 435
 436                 r = (r &  ~(~0ull << (ms_discrep_bit))) | 1 << ms_discrep_bit;
 437         } /* end while true */
 438         dev_dbg(&ds1wm_data->pdev->dev,
 439                 "pass: %d total: %d search done ms d bit pos: %d\n", pass,
 440                 slaves_found, ms_discrep_bit);
 441 }
 442
 443 /* --------------------------------------------------------------------- */
 444
 445 static struct w1_bus_master ds1wm_master = {
 446         .read_byte  = ds1wm_read_byte,
 447         .write_byte = ds1wm_write_byte,
 448         .reset_bus  = ds1wm_reset_bus,
 449         .search     = ds1wm_search,
 450 };
 451
 452 static int ds1wm_probe(struct platform_device *pdev)
 453 {
 454         struct ds1wm_data *ds1wm_data;
 455         struct ds1wm_driver_data *plat;
 456         struct resource *res;
 457         int ret;
 458
 459         if (!pdev)
 460                 return -ENODEV;
 461
 462         ds1wm_data = kzalloc(sizeof(*ds1wm_data), GFP_KERNEL);
 463         if (!ds1wm_data)
 464                 return -ENOMEM;
 465
 466         platform_set_drvdata(pdev, ds1wm_data);
 467
 468         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 469         if (!res) {
 470                 ret = -ENXIO;
 471                 goto err0;
 472         }
 473         ds1wm_data->map = ioremap(res->start, resource_size(res));
 474         if (!ds1wm_data->map) {
 475                 ret = -ENOMEM;
 476                 goto err0;
 477         }
 478
 479         /* calculate bus shift from mem resource */
 480         ds1wm_data->bus_shift = resource_size(res) >> 3;
 481
 482         ds1wm_data->pdev = pdev;
 483         ds1wm_data->cell = mfd_get_cell(pdev);
 484         if (!ds1wm_data->cell) {
 485                 ret = -ENODEV;
 486                 goto err1;
 487         }
 488         plat = pdev->dev.platform_data;
 489         if (!plat) {
 490                 ret = -ENODEV;
 491                 goto err1;
 492         }
 493
 494         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 495         if (!res) {
 496                 ret = -ENXIO;
 497                 goto err1;
 498         }
 499         ds1wm_data->irq = res->start;
 500         ds1wm_data->int_en_reg_none = (plat->active_high ? DS1WM_INTEN_IAS : 0);
 501         ds1wm_data->reset_recover_delay = plat->reset_recover_delay;
 502
 503         if (res->flags & IORESOURCE_IRQ_HIGHEDGE)
 504                 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_RISING);
 505         if (res->flags & IORESOURCE_IRQ_LOWEDGE)
 506                 irq_set_irq_type(ds1wm_data->irq, IRQ_TYPE_EDGE_FALLING);
 507
 508         ret = request_irq(ds1wm_data->irq, ds1wm_isr,
 509                         IRQF_DISABLED | IRQF_SHARED, "ds1wm", ds1wm_data);
 510         if (ret)
 511                 goto err1;
 512
 513         ds1wm_up(ds1wm_data);
 514
 515         ds1wm_master.data = (void *)ds1wm_data;
 516
 517         ret = w1_add_master_device(&ds1wm_master);
 518         if (ret)
 519                 goto err2;
 520
 521         return 0;
 522
 523 err2:
 524         ds1wm_down(ds1wm_data);
 525         free_irq(ds1wm_data->irq, ds1wm_data);
 526 err1:
 527         iounmap(ds1wm_data->map);
 528 err0:
 529         kfree(ds1wm_data);
 530
 531         return ret;
 532 }
 533
 534 #ifdef CONFIG_PM
 535 static int ds1wm_suspend(struct platform_device *pdev, pm_message_t state)
 536 {
 537         struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
 538
 539         ds1wm_down(ds1wm_data);
 540
 541         return 0;
 542 }
 543
 544 static int ds1wm_resume(struct platform_device *pdev)
 545 {
 546         struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
 547
 548         ds1wm_up(ds1wm_data);
 549
 550         return 0;
 551 }
 552 #else
 553 #define ds1wm_suspend NULL
 554 #define ds1wm_resume NULL
 555 #endif
 556
 557 static int ds1wm_remove(struct platform_device *pdev)
 558 {
 559         struct ds1wm_data *ds1wm_data = platform_get_drvdata(pdev);
 560
 561         w1_remove_master_device(&ds1wm_master);
 562         ds1wm_down(ds1wm_data);
 563         free_irq(ds1wm_data->irq, ds1wm_data);
 564         iounmap(ds1wm_data->map);
 565         kfree(ds1wm_data);
 566
 567         return 0;
 568 }
 569
 570 static struct platform_driver ds1wm_driver = {
 571         .driver   = {
 572                 .name = "ds1wm",
 573         },
 574         .probe    = ds1wm_probe,
 575         .remove   = ds1wm_remove,
 576         .suspend  = ds1wm_suspend,
 577         .resume   = ds1wm_resume
 578 };
 579
 580 static int __init ds1wm_init(void)
 581 {
 582         printk("DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko\n");
 583         return platform_driver_register(&ds1wm_driver);
 584 }
 585
 586 static void __exit ds1wm_exit(void)
 587 {
 588         platform_driver_unregister(&ds1wm_driver);
 589 }
 590
 591 module_init(ds1wm_init);
 592 module_exit(ds1wm_exit);
 593
 594 MODULE_LICENSE("GPL");
 595 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
 596         "Matt Reimer <mreimer@vpop.net>,"
 597         "Jean-Francois Dagenais <dagenaisj@sonatest.com>");
 598 MODULE_DESCRIPTION("DS1WM w1 busmaster driver");