drivers/hwmon/i5k_amb.c

   1 /*
   2  * A hwmon driver for the Intel 5000 series chipset FB-DIMM AMB
   3  * temperature sensors
   4  * Copyright (C) 2007 IBM
   5  *
   6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/hwmon.h>
  25 #include <linux/hwmon-sysfs.h>
  26 #include <linux/err.h>
  27 #include <linux/mutex.h>
  28 #include <linux/log2.h>
  29 #include <linux/pci.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/slab.h>
  32
  33 #define DRVNAME "i5k_amb"
  34
  35 #define I5K_REG_AMB_BASE_ADDR           0x48
  36 #define I5K_REG_AMB_LEN_ADDR            0x50
  37 #define I5K_REG_CHAN0_PRESENCE_ADDR     0x64
  38 #define I5K_REG_CHAN1_PRESENCE_ADDR     0x66
  39
  40 #define AMB_REG_TEMP_MIN_ADDR           0x80
  41 #define AMB_REG_TEMP_MID_ADDR           0x81
  42 #define AMB_REG_TEMP_MAX_ADDR           0x82
  43 #define AMB_REG_TEMP_STATUS_ADDR        0x84
  44 #define AMB_REG_TEMP_ADDR               0x85
  45
  46 #define AMB_CONFIG_SIZE                 2048
  47 #define AMB_FUNC_3_OFFSET               768
  48
  49 static unsigned long amb_reg_temp_status(unsigned int amb)
  50 {
  51         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_STATUS_ADDR +
  52                AMB_CONFIG_SIZE * amb;
  53 }
  54
  55 static unsigned long amb_reg_temp_min(unsigned int amb)
  56 {
  57         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MIN_ADDR +
  58                AMB_CONFIG_SIZE * amb;
  59 }
  60
  61 static unsigned long amb_reg_temp_mid(unsigned int amb)
  62 {
  63         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MID_ADDR +
  64                AMB_CONFIG_SIZE * amb;
  65 }
  66
  67 static unsigned long amb_reg_temp_max(unsigned int amb)
  68 {
  69         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MAX_ADDR +
  70                AMB_CONFIG_SIZE * amb;
  71 }
  72
  73 static unsigned long amb_reg_temp(unsigned int amb)
  74 {
  75         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_ADDR +
  76                AMB_CONFIG_SIZE * amb;
  77 }
  78
  79 #define MAX_MEM_CHANNELS                4
  80 #define MAX_AMBS_PER_CHANNEL            16
  81 #define MAX_AMBS                        (MAX_MEM_CHANNELS * \
  82                                          MAX_AMBS_PER_CHANNEL)
  83 #define CHANNEL_SHIFT                   4
  84 #define DIMM_MASK                       0xF
  85 /*
  86  * Ugly hack: For some reason the highest bit is set if there
  87  * are _any_ DIMMs in the channel.  Attempting to read from
  88  * this "high-order" AMB results in a memory bus error, so
  89  * for now we'll just ignore that top bit, even though that
  90  * might prevent us from seeing the 16th DIMM in the channel.
  91  */
  92 #define REAL_MAX_AMBS_PER_CHANNEL       15
  93 #define KNOBS_PER_AMB                   6
  94
  95 static unsigned long amb_num_from_reg(unsigned int byte_num, unsigned int bit)
  96 {
  97         return byte_num * MAX_AMBS_PER_CHANNEL + bit;
  98 }
  99
 100 #define AMB_SYSFS_NAME_LEN              16
 101 struct i5k_device_attribute {
 102         struct sensor_device_attribute s_attr;
 103         char name[AMB_SYSFS_NAME_LEN];
 104 };
 105
 106 struct i5k_amb_data {
 107         struct device *hwmon_dev;
 108
 109         unsigned long amb_base;
 110         unsigned long amb_len;
 111         u16 amb_present[MAX_MEM_CHANNELS];
 112         void __iomem *amb_mmio;
 113         struct i5k_device_attribute *attrs;
 114         unsigned int num_attrs;
 115 };
 116
 117 static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
 118                          char *buf)
 119 {
 120         return sprintf(buf, "%s\n", DRVNAME);
 121 }
 122
 123
 124 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 125
 126 static struct platform_device *amb_pdev;
 127
 128 static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
 129 {
 130         return ioread8(data->amb_mmio + offset);
 131 }
 132
 133 static void amb_write_byte(struct i5k_amb_data *data, unsigned long offset,
 134                            u8 val)
 135 {
 136         iowrite8(val, data->amb_mmio + offset);
 137 }
 138
 139 static ssize_t show_amb_alarm(struct device *dev,
 140                              struct device_attribute *devattr,
 141                              char *buf)
 142 {
 143         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 144         struct i5k_amb_data *data = dev_get_drvdata(dev);
 145
 146         if (!(amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x20) &&
 147              (amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x8))
 148                 return sprintf(buf, "1\n");
 149         else
 150                 return sprintf(buf, "0\n");
 151 }
 152
 153 static ssize_t store_amb_min(struct device *dev,
 154                              struct device_attribute *devattr,
 155                              const char *buf,
 156                              size_t count)
 157 {
 158         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 159         struct i5k_amb_data *data = dev_get_drvdata(dev);
 160         unsigned long temp;
 161         int ret = kstrtoul(buf, 10, &temp);
 162         if (ret < 0)
 163                 return ret;
 164
 165         temp = temp / 500;
 166         if (temp > 255)
 167                 temp = 255;
 168
 169         amb_write_byte(data, amb_reg_temp_min(attr->index), temp);
 170         return count;
 171 }
 172
 173 static ssize_t store_amb_mid(struct device *dev,
 174                              struct device_attribute *devattr,
 175                              const char *buf,
 176                              size_t count)
 177 {
 178         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 179         struct i5k_amb_data *data = dev_get_drvdata(dev);
 180         unsigned long temp;
 181         int ret = kstrtoul(buf, 10, &temp);
 182         if (ret < 0)
 183                 return ret;
 184
 185         temp = temp / 500;
 186         if (temp > 255)
 187                 temp = 255;
 188
 189         amb_write_byte(data, amb_reg_temp_mid(attr->index), temp);
 190         return count;
 191 }
 192
 193 static ssize_t store_amb_max(struct device *dev,
 194                              struct device_attribute *devattr,
 195                              const char *buf,
 196                              size_t count)
 197 {
 198         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 199         struct i5k_amb_data *data = dev_get_drvdata(dev);
 200         unsigned long temp;
 201         int ret = kstrtoul(buf, 10, &temp);
 202         if (ret < 0)
 203                 return ret;
 204
 205         temp = temp / 500;
 206         if (temp > 255)
 207                 temp = 255;
 208
 209         amb_write_byte(data, amb_reg_temp_max(attr->index), temp);
 210         return count;
 211 }
 212
 213 static ssize_t show_amb_min(struct device *dev,
 214                              struct device_attribute *devattr,
 215                              char *buf)
 216 {
 217         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 218         struct i5k_amb_data *data = dev_get_drvdata(dev);
 219         return sprintf(buf, "%d\n",
 220                 500 * amb_read_byte(data, amb_reg_temp_min(attr->index)));
 221 }
 222
 223 static ssize_t show_amb_mid(struct device *dev,
 224                              struct device_attribute *devattr,
 225                              char *buf)
 226 {
 227         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 228         struct i5k_amb_data *data = dev_get_drvdata(dev);
 229         return sprintf(buf, "%d\n",
 230                 500 * amb_read_byte(data, amb_reg_temp_mid(attr->index)));
 231 }
 232
 233 static ssize_t show_amb_max(struct device *dev,
 234                              struct device_attribute *devattr,
 235                              char *buf)
 236 {
 237         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 238         struct i5k_amb_data *data = dev_get_drvdata(dev);
 239         return sprintf(buf, "%d\n",
 240                 500 * amb_read_byte(data, amb_reg_temp_max(attr->index)));
 241 }
 242
 243 static ssize_t show_amb_temp(struct device *dev,
 244                              struct device_attribute *devattr,
 245                              char *buf)
 246 {
 247         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 248         struct i5k_amb_data *data = dev_get_drvdata(dev);
 249         return sprintf(buf, "%d\n",
 250                 500 * amb_read_byte(data, amb_reg_temp(attr->index)));
 251 }
 252
 253 static ssize_t show_label(struct device *dev,
 254                           struct device_attribute *devattr,
 255                           char *buf)
 256 {
 257         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 258
 259         return sprintf(buf, "Ch. %d DIMM %d\n", attr->index >> CHANNEL_SHIFT,
 260                        attr->index & DIMM_MASK);
 261 }
 262
 263 static int i5k_amb_hwmon_init(struct platform_device *pdev)
 264 {
 265         int i, j, k, d = 0;
 266         u16 c;
 267         int res = 0;
 268         int num_ambs = 0;
 269         struct i5k_amb_data *data = platform_get_drvdata(pdev);
 270
 271         /* Count the number of AMBs found */
 272         /* ignore the high-order bit, see "Ugly hack" comment above */
 273         for (i = 0; i < MAX_MEM_CHANNELS; i++)
 274                 num_ambs += hweight16(data->amb_present[i] & 0x7fff);
 275
 276         /* Set up sysfs stuff */
 277         data->attrs = kzalloc(sizeof(*data->attrs) * num_ambs * KNOBS_PER_AMB,
 278                                 GFP_KERNEL);
 279         if (!data->attrs)
 280                 return -ENOMEM;
 281         data->num_attrs = 0;
 282
 283         for (i = 0; i < MAX_MEM_CHANNELS; i++) {
 284                 c = data->amb_present[i];
 285                 for (j = 0; j < REAL_MAX_AMBS_PER_CHANNEL; j++, c >>= 1) {
 286                         struct i5k_device_attribute *iattr;
 287
 288                         k = amb_num_from_reg(i, j);
 289                         if (!(c & 0x1))
 290                                 continue;
 291                         d++;
 292
 293                         /* sysfs label */
 294                         iattr = data->attrs + data->num_attrs;
 295                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 296                                  "temp%d_label", d);
 297                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 298                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 299                         iattr->s_attr.dev_attr.show = show_label;
 300                         iattr->s_attr.index = k;
 301                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 302                         res = device_create_file(&pdev->dev,
 303                                                  &iattr->s_attr.dev_attr);
 304                         if (res)
 305                                 goto exit_remove;
 306                         data->num_attrs++;
 307
 308                         /* Temperature sysfs knob */
 309                         iattr = data->attrs + data->num_attrs;
 310                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 311                                  "temp%d_input", d);
 312                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 313                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 314                         iattr->s_attr.dev_attr.show = show_amb_temp;
 315                         iattr->s_attr.index = k;
 316                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 317                         res = device_create_file(&pdev->dev,
 318                                                  &iattr->s_attr.dev_attr);
 319                         if (res)
 320                                 goto exit_remove;
 321                         data->num_attrs++;
 322
 323                         /* Temperature min sysfs knob */
 324                         iattr = data->attrs + data->num_attrs;
 325                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 326                                  "temp%d_min", d);
 327                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 328                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 329                         iattr->s_attr.dev_attr.show = show_amb_min;
 330                         iattr->s_attr.dev_attr.store = store_amb_min;
 331                         iattr->s_attr.index = k;
 332                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 333                         res = device_create_file(&pdev->dev,
 334                                                  &iattr->s_attr.dev_attr);
 335                         if (res)
 336                                 goto exit_remove;
 337                         data->num_attrs++;
 338
 339                         /* Temperature mid sysfs knob */
 340                         iattr = data->attrs + data->num_attrs;
 341                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 342                                  "temp%d_mid", d);
 343                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 344                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 345                         iattr->s_attr.dev_attr.show = show_amb_mid;
 346                         iattr->s_attr.dev_attr.store = store_amb_mid;
 347                         iattr->s_attr.index = k;
 348                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 349                         res = device_create_file(&pdev->dev,
 350                                                  &iattr->s_attr.dev_attr);
 351                         if (res)
 352                                 goto exit_remove;
 353                         data->num_attrs++;
 354
 355                         /* Temperature max sysfs knob */
 356                         iattr = data->attrs + data->num_attrs;
 357                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 358                                  "temp%d_max", d);
 359                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 360                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 361                         iattr->s_attr.dev_attr.show = show_amb_max;
 362                         iattr->s_attr.dev_attr.store = store_amb_max;
 363                         iattr->s_attr.index = k;
 364                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 365                         res = device_create_file(&pdev->dev,
 366                                                  &iattr->s_attr.dev_attr);
 367                         if (res)
 368                                 goto exit_remove;
 369                         data->num_attrs++;
 370
 371                         /* Temperature alarm sysfs knob */
 372                         iattr = data->attrs + data->num_attrs;
 373                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 374                                  "temp%d_alarm", d);
 375                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 376                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 377                         iattr->s_attr.dev_attr.show = show_amb_alarm;
 378                         iattr->s_attr.index = k;
 379                         sysfs_attr_init(&iattr->s_attr.dev_attr.attr);
 380                         res = device_create_file(&pdev->dev,
 381                                                  &iattr->s_attr.dev_attr);
 382                         if (res)
 383                                 goto exit_remove;
 384                         data->num_attrs++;
 385                 }
 386         }
 387
 388         res = device_create_file(&pdev->dev, &dev_attr_name);
 389         if (res)
 390                 goto exit_remove;
 391
 392         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 393         if (IS_ERR(data->hwmon_dev)) {
 394                 res = PTR_ERR(data->hwmon_dev);
 395                 goto exit_remove;
 396         }
 397
 398         return res;
 399
 400 exit_remove:
 401         device_remove_file(&pdev->dev, &dev_attr_name);
 402         for (i = 0; i < data->num_attrs; i++)
 403                 device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 404         kfree(data->attrs);
 405
 406         return res;
 407 }
 408
 409 static int i5k_amb_add(void)
 410 {
 411         int res = -ENODEV;
 412
 413         /* only ever going to be one of these */
 414         amb_pdev = platform_device_alloc(DRVNAME, 0);
 415         if (!amb_pdev)
 416                 return -ENOMEM;
 417
 418         res = platform_device_add(amb_pdev);
 419         if (res)
 420                 goto err;
 421         return 0;
 422
 423 err:
 424         platform_device_put(amb_pdev);
 425         return res;
 426 }
 427
 428 static int i5k_find_amb_registers(struct i5k_amb_data *data,
 429                                             unsigned long devid)
 430 {
 431         struct pci_dev *pcidev;
 432         u32 val32;
 433         int res = -ENODEV;
 434
 435         /* Find AMB register memory space */
 436         pcidev = pci_get_device(PCI_VENDOR_ID_INTEL,
 437                                 devid,
 438                                 NULL);
 439         if (!pcidev)
 440                 return -ENODEV;
 441
 442         if (pci_read_config_dword(pcidev, I5K_REG_AMB_BASE_ADDR, &val32))
 443                 goto out;
 444         data->amb_base = val32;
 445
 446         if (pci_read_config_dword(pcidev, I5K_REG_AMB_LEN_ADDR, &val32))
 447                 goto out;
 448         data->amb_len = val32;
 449
 450         /* Is it big enough? */
 451         if (data->amb_len < AMB_CONFIG_SIZE * MAX_AMBS) {
 452                 dev_err(&pcidev->dev, "AMB region too small!\n");
 453                 goto out;
 454         }
 455
 456         res = 0;
 457 out:
 458         pci_dev_put(pcidev);
 459         return res;
 460 }
 461
 462 static int i5k_channel_probe(u16 *amb_present, unsigned long dev_id)
 463 {
 464         struct pci_dev *pcidev;
 465         u16 val16;
 466         int res = -ENODEV;
 467
 468         /* Copy the DIMM presence map for these two channels */
 469         pcidev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
 470         if (!pcidev)
 471                 return -ENODEV;
 472
 473         if (pci_read_config_word(pcidev, I5K_REG_CHAN0_PRESENCE_ADDR, &val16))
 474                 goto out;
 475         amb_present[0] = val16;
 476
 477         if (pci_read_config_word(pcidev, I5K_REG_CHAN1_PRESENCE_ADDR, &val16))
 478                 goto out;
 479         amb_present[1] = val16;
 480
 481         res = 0;
 482
 483 out:
 484         pci_dev_put(pcidev);
 485         return res;
 486 }
 487
 488 static struct {
 489         unsigned long err;
 490         unsigned long fbd0;
 491 } chipset_ids[]  = {
 492         { PCI_DEVICE_ID_INTEL_5000_ERR, PCI_DEVICE_ID_INTEL_5000_FBD0 },
 493         { PCI_DEVICE_ID_INTEL_5400_ERR, PCI_DEVICE_ID_INTEL_5400_FBD0 },
 494         { 0, 0 }
 495 };
 496
 497 #ifdef MODULE
 498 static struct pci_device_id i5k_amb_ids[] = {
 499         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5000_ERR) },
 500         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5400_ERR) },
 501         { 0, }
 502 };
 503 MODULE_DEVICE_TABLE(pci, i5k_amb_ids);
 504 #endif
 505
 506 static int i5k_amb_probe(struct platform_device *pdev)
 507 {
 508         struct i5k_amb_data *data;
 509         struct resource *reso;
 510         int i, res;
 511
 512         data = kzalloc(sizeof(*data), GFP_KERNEL);
 513         if (!data)
 514                 return -ENOMEM;
 515
 516         /* Figure out where the AMB registers live */
 517         i = 0;
 518         do {
 519                 res = i5k_find_amb_registers(data, chipset_ids[i].err);
 520                 if (res == 0)
 521                         break;
 522                 i++;
 523         } while (chipset_ids[i].err);
 524
 525         if (res)
 526                 goto err;
 527
 528         /* Copy the DIMM presence map for the first two channels */
 529         res = i5k_channel_probe(&data->amb_present[0], chipset_ids[i].fbd0);
 530         if (res)
 531                 goto err;
 532
 533         /* Copy the DIMM presence map for the optional second two channels */
 534         i5k_channel_probe(&data->amb_present[2], chipset_ids[i].fbd0 + 1);
 535
 536         /* Set up resource regions */
 537         reso = request_mem_region(data->amb_base, data->amb_len, DRVNAME);
 538         if (!reso) {
 539                 res = -EBUSY;
 540                 goto err;
 541         }
 542
 543         data->amb_mmio = ioremap_nocache(data->amb_base, data->amb_len);
 544         if (!data->amb_mmio) {
 545                 res = -EBUSY;
 546                 goto err_map_failed;
 547         }
 548
 549         platform_set_drvdata(pdev, data);
 550
 551         res = i5k_amb_hwmon_init(pdev);
 552         if (res)
 553                 goto err_init_failed;
 554
 555         return res;
 556
 557 err_init_failed:
 558         iounmap(data->amb_mmio);
 559 err_map_failed:
 560         release_mem_region(data->amb_base, data->amb_len);
 561 err:
 562         kfree(data);
 563         return res;
 564 }
 565
 566 static int i5k_amb_remove(struct platform_device *pdev)
 567 {
 568         int i;
 569         struct i5k_amb_data *data = platform_get_drvdata(pdev);
 570
 571         hwmon_device_unregister(data->hwmon_dev);
 572         device_remove_file(&pdev->dev, &dev_attr_name);
 573         for (i = 0; i < data->num_attrs; i++)
 574                 device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 575         kfree(data->attrs);
 576         iounmap(data->amb_mmio);
 577         release_mem_region(data->amb_base, data->amb_len);
 578         kfree(data);
 579         return 0;
 580 }
 581
 582 static struct platform_driver i5k_amb_driver = {
 583         .driver = {
 584                 .name = DRVNAME,
 585         },
 586         .probe = i5k_amb_probe,
 587         .remove = i5k_amb_remove,
 588 };
 589
 590 static int __init i5k_amb_init(void)
 591 {
 592         int res;
 593
 594         res = platform_driver_register(&i5k_amb_driver);
 595         if (res)
 596                 return res;
 597
 598         res = i5k_amb_add();
 599         if (res)
 600                 platform_driver_unregister(&i5k_amb_driver);
 601
 602         return res;
 603 }
 604
 605 static void __exit i5k_amb_exit(void)
 606 {
 607         platform_device_unregister(amb_pdev);
 608         platform_driver_unregister(&i5k_amb_driver);
 609 }
 610
 611 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
 612 MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
 613 MODULE_LICENSE("GPL");
 614
 615 module_init(i5k_amb_init);
 616 module_exit(i5k_amb_exit);