drivers/fsi/fsi-scom.c

   1 /*
   2  * SCOM FSI Client device driver
   3  *
   4  * Copyright (C) IBM Corporation 2016
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/fsi.h>
  17 #include <linux/module.h>
  18 #include <linux/cdev.h>
  19 #include <linux/delay.h>
  20 #include <linux/fs.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/slab.h>
  23 #include <linux/cdev.h>
  24 #include <linux/list.h>
  25
  26 #include <uapi/linux/fsi.h>
  27
  28 #define FSI_ENGID_SCOM          0x5
  29
  30 /* SCOM engine register set */
  31 #define SCOM_DATA0_REG          0x00
  32 #define SCOM_DATA1_REG          0x04
  33 #define SCOM_CMD_REG            0x08
  34 #define SCOM_FSI2PIB_RESET_REG  0x18
  35 #define SCOM_STATUS_REG         0x1C /* Read */
  36 #define SCOM_PIB_RESET_REG      0x1C /* Write */
  37
  38 /* Command register */
  39 #define SCOM_WRITE_CMD          0x80000000
  40 #define SCOM_READ_CMD           0x00000000
  41
  42 /* Status register bits */
  43 #define SCOM_STATUS_ERR_SUMMARY         0x80000000
  44 #define SCOM_STATUS_PROTECTION          0x01000000
  45 #define SCOM_STATUS_PARITY              0x04000000
  46 #define SCOM_STATUS_PIB_ABORT           0x00100000
  47 #define SCOM_STATUS_PIB_RESP_MASK       0x00007000
  48 #define SCOM_STATUS_PIB_RESP_SHIFT      12
  49
  50 #define SCOM_STATUS_ANY_ERR             (SCOM_STATUS_PROTECTION | \
  51                                          SCOM_STATUS_PARITY |     \
  52                                          SCOM_STATUS_PIB_ABORT | \
  53                                          SCOM_STATUS_PIB_RESP_MASK)
  54 /* SCOM address encodings */
  55 #define XSCOM_ADDR_IND_FLAG             BIT_ULL(63)
  56 #define XSCOM_ADDR_INF_FORM1            BIT_ULL(60)
  57
  58 /* SCOM indirect stuff */
  59 #define XSCOM_ADDR_DIRECT_PART          0x7fffffffull
  60 #define XSCOM_ADDR_INDIRECT_PART        0x000fffff00000000ull
  61 #define XSCOM_DATA_IND_READ             BIT_ULL(63)
  62 #define XSCOM_DATA_IND_COMPLETE         BIT_ULL(31)
  63 #define XSCOM_DATA_IND_ERR_MASK         0x70000000ull
  64 #define XSCOM_DATA_IND_ERR_SHIFT        28
  65 #define XSCOM_DATA_IND_DATA             0x0000ffffull
  66 #define XSCOM_DATA_IND_FORM1_DATA       0x000fffffffffffffull
  67 #define XSCOM_ADDR_FORM1_LOW            0x000ffffffffull
  68 #define XSCOM_ADDR_FORM1_HI             0xfff00000000ull
  69 #define XSCOM_ADDR_FORM1_HI_SHIFT       20
  70
  71 /* Retries */
  72 #define SCOM_MAX_RETRIES                100     /* Retries on busy */
  73 #define SCOM_MAX_IND_RETRIES            10      /* Retries indirect not ready */
  74
  75 struct scom_device {
  76         struct list_head link;
  77         struct fsi_device *fsi_dev;
  78         struct device dev;
  79         struct cdev cdev;
  80         struct mutex lock;
  81         bool dead;
  82 };
  83
  84 static int __put_scom(struct scom_device *scom_dev, uint64_t value,
  85                       uint32_t addr, uint32_t *status)
  86 {
  87         __be32 data, raw_status;
  88         int rc;
  89
  90         data = cpu_to_be32((value >> 32) & 0xffffffff);
  91         rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
  92                                 sizeof(uint32_t));
  93         if (rc)
  94                 return rc;
  95
  96         data = cpu_to_be32(value & 0xffffffff);
  97         rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
  98                                 sizeof(uint32_t));
  99         if (rc)
 100                 return rc;
 101
 102         data = cpu_to_be32(SCOM_WRITE_CMD | addr);
 103         rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
 104                                 sizeof(uint32_t));
 105         if (rc)
 106                 return rc;
 107         rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
 108                              sizeof(uint32_t));
 109         if (rc)
 110                 return rc;
 111         *status = be32_to_cpu(raw_status);
 112
 113         return 0;
 114 }
 115
 116 static int __get_scom(struct scom_device *scom_dev, uint64_t *value,
 117                       uint32_t addr, uint32_t *status)
 118 {
 119         __be32 data, raw_status;
 120         int rc;
 121
 122
 123         *value = 0ULL;
 124         data = cpu_to_be32(SCOM_READ_CMD | addr);
 125         rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data,
 126                                 sizeof(uint32_t));
 127         if (rc)
 128                 return rc;
 129         rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status,
 130                              sizeof(uint32_t));
 131         if (rc)
 132                 return rc;
 133
 134         /*
 135          * Read the data registers even on error, so we don't have
 136          * to interpret the status register here.
 137          */
 138         rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &data,
 139                                 sizeof(uint32_t));
 140         if (rc)
 141                 return rc;
 142         *value |= (uint64_t)be32_to_cpu(data) << 32;
 143         rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &data,
 144                                 sizeof(uint32_t));
 145         if (rc)
 146                 return rc;
 147         *value |= be32_to_cpu(data);
 148         *status = be32_to_cpu(raw_status);
 149
 150         return rc;
 151 }
 152
 153 static int put_indirect_scom_form0(struct scom_device *scom, uint64_t value,
 154                                    uint64_t addr, uint32_t *status)
 155 {
 156         uint64_t ind_data, ind_addr;
 157         int rc, retries, err = 0;
 158
 159         if (value & ~XSCOM_DATA_IND_DATA)
 160                 return -EINVAL;
 161
 162         ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
 163         ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | value;
 164         rc = __put_scom(scom, ind_data, ind_addr, status);
 165         if (rc || (*status & SCOM_STATUS_ANY_ERR))
 166                 return rc;
 167
 168         for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) {
 169                 rc = __get_scom(scom, &ind_data, addr, status);
 170                 if (rc || (*status & SCOM_STATUS_ANY_ERR))
 171                         return rc;
 172
 173                 err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
 174                 *status = err << SCOM_STATUS_PIB_RESP_SHIFT;
 175                 if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED))
 176                         return 0;
 177
 178                 msleep(1);
 179         }
 180         return rc;
 181 }
 182
 183 static int put_indirect_scom_form1(struct scom_device *scom, uint64_t value,
 184                                    uint64_t addr, uint32_t *status)
 185 {
 186         uint64_t ind_data, ind_addr;
 187
 188         if (value & ~XSCOM_DATA_IND_FORM1_DATA)
 189                 return -EINVAL;
 190
 191         ind_addr = addr & XSCOM_ADDR_FORM1_LOW;
 192         ind_data = value | (addr & XSCOM_ADDR_FORM1_HI) << XSCOM_ADDR_FORM1_HI_SHIFT;
 193         return __put_scom(scom, ind_data, ind_addr, status);
 194 }
 195
 196 static int get_indirect_scom_form0(struct scom_device *scom, uint64_t *value,
 197                                    uint64_t addr, uint32_t *status)
 198 {
 199         uint64_t ind_data, ind_addr;
 200         int rc, retries, err = 0;
 201
 202         ind_addr = addr & XSCOM_ADDR_DIRECT_PART;
 203         ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | XSCOM_DATA_IND_READ;
 204         rc = __put_scom(scom, ind_data, ind_addr, status);
 205         if (rc || (*status & SCOM_STATUS_ANY_ERR))
 206                 return rc;
 207
 208         for (retries = 0; retries < SCOM_MAX_IND_RETRIES; retries++) {
 209                 rc = __get_scom(scom, &ind_data, addr, status);
 210                 if (rc || (*status & SCOM_STATUS_ANY_ERR))
 211                         return rc;
 212
 213                 err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT;
 214                 *status = err << SCOM_STATUS_PIB_RESP_SHIFT;
 215                 *value = ind_data & XSCOM_DATA_IND_DATA;
 216
 217                 if ((ind_data & XSCOM_DATA_IND_COMPLETE) || (err != SCOM_PIB_BLOCKED))
 218                         return 0;
 219
 220                 msleep(1);
 221         }
 222         return rc;
 223 }
 224
 225 static int raw_put_scom(struct scom_device *scom, uint64_t value,
 226                         uint64_t addr, uint32_t *status)
 227 {
 228         if (addr & XSCOM_ADDR_IND_FLAG) {
 229                 if (addr & XSCOM_ADDR_INF_FORM1)
 230                         return put_indirect_scom_form1(scom, value, addr, status);
 231                 else
 232                         return put_indirect_scom_form0(scom, value, addr, status);
 233         } else
 234                 return __put_scom(scom, value, addr, status);
 235 }
 236
 237 static int raw_get_scom(struct scom_device *scom, uint64_t *value,
 238                         uint64_t addr, uint32_t *status)
 239 {
 240         if (addr & XSCOM_ADDR_IND_FLAG) {
 241                 if (addr & XSCOM_ADDR_INF_FORM1)
 242                         return -ENXIO;
 243                 return get_indirect_scom_form0(scom, value, addr, status);
 244         } else
 245                 return __get_scom(scom, value, addr, status);
 246 }
 247
 248 static int handle_fsi2pib_status(struct scom_device *scom, uint32_t status)
 249 {
 250         uint32_t dummy = -1;
 251
 252         if (status & SCOM_STATUS_PROTECTION)
 253                 return -EPERM;
 254         if (status & SCOM_STATUS_PARITY) {
 255                 fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
 256                                  sizeof(uint32_t));
 257                 return -EIO;
 258         }
 259         /* Return -EBUSY on PIB abort to force a retry */
 260         if (status & SCOM_STATUS_PIB_ABORT)
 261                 return -EBUSY;
 262         return 0;
 263 }
 264
 265 static int handle_pib_status(struct scom_device *scom, uint8_t status)
 266 {
 267         uint32_t dummy = -1;
 268
 269         if (status == SCOM_PIB_SUCCESS)
 270                 return 0;
 271         if (status == SCOM_PIB_BLOCKED)
 272                 return -EBUSY;
 273
 274         /* Reset the bridge */
 275         fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
 276                          sizeof(uint32_t));
 277
 278         switch(status) {
 279         case SCOM_PIB_OFFLINE:
 280                 return -ENODEV;
 281         case SCOM_PIB_BAD_ADDR:
 282                 return -ENXIO;
 283         case SCOM_PIB_TIMEOUT:
 284                 return -ETIMEDOUT;
 285         case SCOM_PIB_PARTIAL:
 286         case SCOM_PIB_CLK_ERR:
 287         case SCOM_PIB_PARITY_ERR:
 288         default:
 289                 return -EIO;
 290         }
 291 }
 292
 293 static int put_scom(struct scom_device *scom, uint64_t value,
 294                     uint64_t addr)
 295 {
 296         uint32_t status, dummy = -1;
 297         int rc, retries;
 298
 299         for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) {
 300                 rc = raw_put_scom(scom, value, addr, &status);
 301                 if (rc) {
 302                         /* Try resetting the bridge if FSI fails */
 303                         if (rc != -ENODEV && retries == 0) {
 304                                 fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG,
 305                                                  &dummy, sizeof(uint32_t));
 306                                 rc = -EBUSY;
 307                         } else
 308                                 return rc;
 309                 } else
 310                         rc = handle_fsi2pib_status(scom, status);
 311                 if (rc && rc != -EBUSY)
 312                         break;
 313                 if (rc == 0) {
 314                         rc = handle_pib_status(scom,
 315                                                (status & SCOM_STATUS_PIB_RESP_MASK)
 316                                                >> SCOM_STATUS_PIB_RESP_SHIFT);
 317                         if (rc && rc != -EBUSY)
 318                                 break;
 319                 }
 320                 if (rc == 0)
 321                         break;
 322                 msleep(1);
 323         }
 324         return rc;
 325 }
 326
 327 static int get_scom(struct scom_device *scom, uint64_t *value,
 328                     uint64_t addr)
 329 {
 330         uint32_t status, dummy = -1;
 331         int rc, retries;
 332
 333         for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) {
 334                 rc = raw_get_scom(scom, value, addr, &status);
 335                 if (rc) {
 336                         /* Try resetting the bridge if FSI fails */
 337                         if (rc != -ENODEV && retries == 0) {
 338                                 fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG,
 339                                                  &dummy, sizeof(uint32_t));
 340                                 rc = -EBUSY;
 341                         } else
 342                                 return rc;
 343                 } else
 344                         rc = handle_fsi2pib_status(scom, status);
 345                 if (rc && rc != -EBUSY)
 346                         break;
 347                 if (rc == 0) {
 348                         rc = handle_pib_status(scom,
 349                                                (status & SCOM_STATUS_PIB_RESP_MASK)
 350                                                >> SCOM_STATUS_PIB_RESP_SHIFT);
 351                         if (rc && rc != -EBUSY)
 352                                 break;
 353                 }
 354                 if (rc == 0)
 355                         break;
 356                 msleep(1);
 357         }
 358         return rc;
 359 }
 360
 361 static ssize_t scom_read(struct file *filep, char __user *buf, size_t len,
 362                          loff_t *offset)
 363 {
 364         struct scom_device *scom = filep->private_data;
 365         struct device *dev = &scom->fsi_dev->dev;
 366         uint64_t val;
 367         int rc;
 368
 369         if (len != sizeof(uint64_t))
 370                 return -EINVAL;
 371
 372         mutex_lock(&scom->lock);
 373         if (scom->dead)
 374                 rc = -ENODEV;
 375         else
 376                 rc = get_scom(scom, &val, *offset);
 377         mutex_unlock(&scom->lock);
 378         if (rc) {
 379                 dev_dbg(dev, "get_scom fail:%d\n", rc);
 380                 return rc;
 381         }
 382
 383         rc = copy_to_user(buf, &val, len);
 384         if (rc)
 385                 dev_dbg(dev, "copy to user failed:%d\n", rc);
 386
 387         return rc ? rc : len;
 388 }
 389
 390 static ssize_t scom_write(struct file *filep, const char __user *buf,
 391                           size_t len, loff_t *offset)
 392 {
 393         int rc;
 394         struct scom_device *scom = filep->private_data;
 395         struct device *dev = &scom->fsi_dev->dev;
 396         uint64_t val;
 397
 398         if (len != sizeof(uint64_t))
 399                 return -EINVAL;
 400
 401         rc = copy_from_user(&val, buf, len);
 402         if (rc) {
 403                 dev_dbg(dev, "copy from user failed:%d\n", rc);
 404                 return -EINVAL;
 405         }
 406
 407         mutex_lock(&scom->lock);
 408         if (scom->dead)
 409                 rc = -ENODEV;
 410         else
 411                 rc = put_scom(scom, val, *offset);
 412         mutex_unlock(&scom->lock);
 413         if (rc) {
 414                 dev_dbg(dev, "put_scom failed with:%d\n", rc);
 415                 return rc;
 416         }
 417
 418         return len;
 419 }
 420
 421 static loff_t scom_llseek(struct file *file, loff_t offset, int whence)
 422 {
 423         switch (whence) {
 424         case SEEK_CUR:
 425                 break;
 426         case SEEK_SET:
 427                 file->f_pos = offset;
 428                 break;
 429         default:
 430                 return -EINVAL;
 431         }
 432
 433         return offset;
 434 }
 435
 436 static void raw_convert_status(struct scom_access *acc, uint32_t status)
 437 {
 438         acc->pib_status = (status & SCOM_STATUS_PIB_RESP_MASK) >>
 439                 SCOM_STATUS_PIB_RESP_SHIFT;
 440         acc->intf_errors = 0;
 441
 442         if (status & SCOM_STATUS_PROTECTION)
 443                 acc->intf_errors |= SCOM_INTF_ERR_PROTECTION;
 444         else if (status & SCOM_STATUS_PARITY)
 445                 acc->intf_errors |= SCOM_INTF_ERR_PARITY;
 446         else if (status & SCOM_STATUS_PIB_ABORT)
 447                 acc->intf_errors |= SCOM_INTF_ERR_ABORT;
 448         else if (status & SCOM_STATUS_ERR_SUMMARY)
 449                 acc->intf_errors |= SCOM_INTF_ERR_UNKNOWN;
 450 }
 451
 452 static int scom_raw_read(struct scom_device *scom, void __user *argp)
 453 {
 454         struct scom_access acc;
 455         uint32_t status;
 456         int rc;
 457
 458         if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
 459                 return -EFAULT;
 460
 461         rc = raw_get_scom(scom, &acc.data, acc.addr, &status);
 462         if (rc)
 463                 return rc;
 464         raw_convert_status(&acc, status);
 465         if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
 466                 return -EFAULT;
 467         return 0;
 468 }
 469
 470 static int scom_raw_write(struct scom_device *scom, void __user *argp)
 471 {
 472         u64 prev_data, mask, data;
 473         struct scom_access acc;
 474         uint32_t status;
 475         int rc;
 476
 477         if (copy_from_user(&acc, argp, sizeof(struct scom_access)))
 478                 return -EFAULT;
 479
 480         if (acc.mask) {
 481                 rc = raw_get_scom(scom, &prev_data, acc.addr, &status);
 482                 if (rc)
 483                         return rc;
 484                 if (status & SCOM_STATUS_ANY_ERR)
 485                         goto fail;
 486                 mask = acc.mask;
 487         } else {
 488                 prev_data = mask = -1ull;
 489         }
 490         data = (prev_data & ~mask) | (acc.data & mask);
 491         rc = raw_put_scom(scom, data, acc.addr, &status);
 492         if (rc)
 493                 return rc;
 494  fail:
 495         raw_convert_status(&acc, status);
 496         if (copy_to_user(argp, &acc, sizeof(struct scom_access)))
 497                 return -EFAULT;
 498         return 0;
 499 }
 500
 501 static int scom_reset(struct scom_device *scom, void __user *argp)
 502 {
 503         uint32_t flags, dummy = -1;
 504         int rc = 0;
 505
 506         if (get_user(flags, (__u32 __user *)argp))
 507                 return -EFAULT;
 508         if (flags & SCOM_RESET_PIB)
 509                 rc = fsi_device_write(scom->fsi_dev, SCOM_PIB_RESET_REG, &dummy,
 510                                       sizeof(uint32_t));
 511         if (!rc && (flags & (SCOM_RESET_PIB | SCOM_RESET_INTF)))
 512                 rc = fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy,
 513                                       sizeof(uint32_t));
 514         return rc;
 515 }
 516
 517 static int scom_check(struct scom_device *scom, void __user *argp)
 518 {
 519         /* Still need to find out how to get "protected" */
 520         return put_user(SCOM_CHECK_SUPPORTED, (__u32 __user *)argp);
 521 }
 522
 523 static long scom_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 524 {
 525         struct scom_device *scom = file->private_data;
 526         void __user *argp = (void __user *)arg;
 527         int rc = -ENOTTY;
 528
 529         mutex_lock(&scom->lock);
 530         if (scom->dead) {
 531                 mutex_unlock(&scom->lock);
 532                 return -ENODEV;
 533         }
 534         switch(cmd) {
 535         case FSI_SCOM_CHECK:
 536                 rc = scom_check(scom, argp);
 537                 break;
 538         case FSI_SCOM_READ:
 539                 rc = scom_raw_read(scom, argp);
 540                 break;
 541         case FSI_SCOM_WRITE:
 542                 rc = scom_raw_write(scom, argp);
 543                 break;
 544         case FSI_SCOM_RESET:
 545                 rc = scom_reset(scom, argp);
 546                 break;
 547         }
 548         mutex_unlock(&scom->lock);
 549         return rc;
 550 }
 551
 552 static int scom_open(struct inode *inode, struct file *file)
 553 {
 554         struct scom_device *scom = container_of(inode->i_cdev, struct scom_device, cdev);
 555
 556         file->private_data = scom;
 557
 558         return 0;
 559 }
 560
 561 static const struct file_operations scom_fops = {
 562         .owner          = THIS_MODULE,
 563         .open           = scom_open,
 564         .llseek         = scom_llseek,
 565         .read           = scom_read,
 566         .write          = scom_write,
 567         .unlocked_ioctl = scom_ioctl,
 568 };
 569
 570 static void scom_free(struct device *dev)
 571 {
 572         struct scom_device *scom = container_of(dev, struct scom_device, dev);
 573
 574         put_device(&scom->fsi_dev->dev);
 575         kfree(scom);
 576 }
 577
 578 static int scom_probe(struct device *dev)
 579 {
 580         struct fsi_device *fsi_dev = to_fsi_dev(dev);
 581         struct scom_device *scom;
 582         int rc, didx;
 583
 584         scom = kzalloc(sizeof(*scom), GFP_KERNEL);
 585         if (!scom)
 586                 return -ENOMEM;
 587         dev_set_drvdata(dev, scom);
 588         mutex_init(&scom->lock);
 589
 590         /* Grab a reference to the device (parent of our cdev), we'll drop it later */
 591         if (!get_device(dev)) {
 592                 kfree(scom);
 593                 return -ENODEV;
 594         }
 595         scom->fsi_dev = fsi_dev;
 596
 597         /* Create chardev for userspace access */
 598         scom->dev.type = &fsi_cdev_type;
 599         scom->dev.parent = dev;
 600         scom->dev.release = scom_free;
 601         device_initialize(&scom->dev);
 602
 603         /* Allocate a minor in the FSI space */
 604         rc = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx);
 605         if (rc)
 606                 goto err;
 607
 608         dev_set_name(&scom->dev, "scom%d", didx);
 609         cdev_init(&scom->cdev, &scom_fops);
 610         rc = cdev_device_add(&scom->cdev, &scom->dev);
 611         if (rc) {
 612                 dev_err(dev, "Error %d creating char device %s\n",
 613                         rc, dev_name(&scom->dev));
 614                 goto err_free_minor;
 615         }
 616
 617         return 0;
 618  err_free_minor:
 619         fsi_free_minor(scom->dev.devt);
 620  err:
 621         put_device(&scom->dev);
 622         return rc;
 623 }
 624
 625 static int scom_remove(struct device *dev)
 626 {
 627         struct scom_device *scom = dev_get_drvdata(dev);
 628
 629         mutex_lock(&scom->lock);
 630         scom->dead = true;
 631         mutex_unlock(&scom->lock);
 632         cdev_device_del(&scom->cdev, &scom->dev);
 633         fsi_free_minor(scom->dev.devt);
 634         put_device(&scom->dev);
 635
 636         return 0;
 637 }
 638
 639 static struct fsi_device_id scom_ids[] = {
 640         {
 641                 .engine_type = FSI_ENGID_SCOM,
 642                 .version = FSI_VERSION_ANY,
 643         },
 644         { 0 }
 645 };
 646
 647 static struct fsi_driver scom_drv = {
 648         .id_table = scom_ids,
 649         .drv = {
 650                 .name = "scom",
 651                 .bus = &fsi_bus_type,
 652                 .probe = scom_probe,
 653                 .remove = scom_remove,
 654         }
 655 };
 656
 657 static int scom_init(void)
 658 {
 659         return fsi_driver_register(&scom_drv);
 660 }
 661
 662 static void scom_exit(void)
 663 {
 664         fsi_driver_unregister(&scom_drv);
 665 }
 666
 667 module_init(scom_init);
 668 module_exit(scom_exit);
 669 MODULE_LICENSE("GPL");