drivers/misc/enclosure.c

   1 /*
   2  * Enclosure Services
   3  *
   4  * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
   5  *
   6 **-----------------------------------------------------------------------------
   7 **
   8 **  This program is free software; you can redistribute it and/or
   9 **  modify it under the terms of the GNU General Public License
  10 **  version 2 as published by the Free Software Foundation.
  11 **
  12 **  This program is distributed in the hope that it will be useful,
  13 **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 **  GNU General Public License for more details.
  16 **
  17 **  You should have received a copy of the GNU General Public License
  18 **  along with this program; if not, write to the Free Software
  19 **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 **
  21 **-----------------------------------------------------------------------------
  22 */
  23 #include <linux/device.h>
  24 #include <linux/enclosure.h>
  25 #include <linux/err.h>
  26 #include <linux/list.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/mutex.h>
  30
  31 static LIST_HEAD(container_list);
  32 static DEFINE_MUTEX(container_list_lock);
  33 static struct class enclosure_class;
  34 static struct class enclosure_component_class;
  35
  36 /**
  37  * enclosure_find - find an enclosure given a device
  38  * @dev:        the device to find for
  39  *
  40  * Looks through the list of registered enclosures to see
  41  * if it can find a match for a device.  Returns NULL if no
  42  * enclosure is found. Obtains a reference to the enclosure class
  43  * device which must be released with device_put().
  44  */
  45 struct enclosure_device *enclosure_find(struct device *dev)
  46 {
  47         struct enclosure_device *edev;
  48
  49         mutex_lock(&container_list_lock);
  50         list_for_each_entry(edev, &container_list, node) {
  51                 if (edev->edev.parent == dev) {
  52                         get_device(&edev->edev);
  53                         mutex_unlock(&container_list_lock);
  54                         return edev;
  55                 }
  56         }
  57         mutex_unlock(&container_list_lock);
  58
  59         return NULL;
  60 }
  61 EXPORT_SYMBOL_GPL(enclosure_find);
  62
  63 /**
  64  * enclosure_for_each_device - calls a function for each enclosure
  65  * @fn:         the function to call
  66  * @data:       the data to pass to each call
  67  *
  68  * Loops over all the enclosures calling the function.
  69  *
  70  * Note, this function uses a mutex which will be held across calls to
  71  * @fn, so it must have non atomic context, and @fn may (although it
  72  * should not) sleep or otherwise cause the mutex to be held for
  73  * indefinite periods
  74  */
  75 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
  76                               void *data)
  77 {
  78         int error = 0;
  79         struct enclosure_device *edev;
  80
  81         mutex_lock(&container_list_lock);
  82         list_for_each_entry(edev, &container_list, node) {
  83                 error = fn(edev, data);
  84                 if (error)
  85                         break;
  86         }
  87         mutex_unlock(&container_list_lock);
  88
  89         return error;
  90 }
  91 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
  92
  93 /**
  94  * enclosure_register - register device as an enclosure
  95  *
  96  * @dev:        device containing the enclosure
  97  * @components: number of components in the enclosure
  98  *
  99  * This sets up the device for being an enclosure.  Note that @dev does
 100  * not have to be a dedicated enclosure device.  It may be some other type
 101  * of device that additionally responds to enclosure services
 102  */
 103 struct enclosure_device *
 104 enclosure_register(struct device *dev, const char *name, int components,
 105                    struct enclosure_component_callbacks *cb)
 106 {
 107         struct enclosure_device *edev =
 108                 kzalloc(sizeof(struct enclosure_device) +
 109                         sizeof(struct enclosure_component)*components,
 110                         GFP_KERNEL);
 111         int err, i;
 112
 113         BUG_ON(!cb);
 114
 115         if (!edev)
 116                 return ERR_PTR(-ENOMEM);
 117
 118         edev->components = components;
 119
 120         edev->edev.class = &enclosure_class;
 121         edev->edev.parent = get_device(dev);
 122         edev->cb = cb;
 123         snprintf(edev->edev.bus_id, BUS_ID_SIZE, "%s", name);
 124         err = device_register(&edev->edev);
 125         if (err)
 126                 goto err;
 127
 128         for (i = 0; i < components; i++)
 129                 edev->component[i].number = -1;
 130
 131         mutex_lock(&container_list_lock);
 132         list_add_tail(&edev->node, &container_list);
 133         mutex_unlock(&container_list_lock);
 134
 135         return edev;
 136
 137  err:
 138         put_device(edev->edev.parent);
 139         kfree(edev);
 140         return ERR_PTR(err);
 141 }
 142 EXPORT_SYMBOL_GPL(enclosure_register);
 143
 144 static struct enclosure_component_callbacks enclosure_null_callbacks;
 145
 146 /**
 147  * enclosure_unregister - remove an enclosure
 148  *
 149  * @edev:       the registered enclosure to remove;
 150  */
 151 void enclosure_unregister(struct enclosure_device *edev)
 152 {
 153         int i;
 154
 155         mutex_lock(&container_list_lock);
 156         list_del(&edev->node);
 157         mutex_unlock(&container_list_lock);
 158
 159         for (i = 0; i < edev->components; i++)
 160                 if (edev->component[i].number != -1)
 161                         device_unregister(&edev->component[i].cdev);
 162
 163         /* prevent any callbacks into service user */
 164         edev->cb = &enclosure_null_callbacks;
 165         device_unregister(&edev->edev);
 166 }
 167 EXPORT_SYMBOL_GPL(enclosure_unregister);
 168
 169 static void enclosure_release(struct device *cdev)
 170 {
 171         struct enclosure_device *edev = to_enclosure_device(cdev);
 172
 173         put_device(cdev->parent);
 174         kfree(edev);
 175 }
 176
 177 static void enclosure_component_release(struct device *dev)
 178 {
 179         struct enclosure_component *cdev = to_enclosure_component(dev);
 180
 181         put_device(cdev->dev);
 182         put_device(dev->parent);
 183 }
 184
 185 /**
 186  * enclosure_component_register - add a particular component to an enclosure
 187  * @edev:       the enclosure to add the component
 188  * @num:        the device number
 189  * @type:       the type of component being added
 190  * @name:       an optional name to appear in sysfs (leave NULL if none)
 191  *
 192  * Registers the component.  The name is optional for enclosures that
 193  * give their components a unique name.  If not, leave the field NULL
 194  * and a name will be assigned.
 195  *
 196  * Returns a pointer to the enclosure component or an error.
 197  */
 198 struct enclosure_component *
 199 enclosure_component_register(struct enclosure_device *edev,
 200                              unsigned int number,
 201                              enum enclosure_component_type type,
 202                              const char *name)
 203 {
 204         struct enclosure_component *ecomp;
 205         struct device *cdev;
 206         int err;
 207
 208         if (number >= edev->components)
 209                 return ERR_PTR(-EINVAL);
 210
 211         ecomp = &edev->component[number];
 212
 213         if (ecomp->number != -1)
 214                 return ERR_PTR(-EINVAL);
 215
 216         ecomp->type = type;
 217         ecomp->number = number;
 218         cdev = &ecomp->cdev;
 219         cdev->parent = get_device(&edev->edev);
 220         cdev->class = &enclosure_component_class;
 221         if (name)
 222                 snprintf(cdev->bus_id, BUS_ID_SIZE, "%s", name);
 223         else
 224                 snprintf(cdev->bus_id, BUS_ID_SIZE, "%u", number);
 225
 226         err = device_register(cdev);
 227         if (err)
 228                 ERR_PTR(err);
 229
 230         return ecomp;
 231 }
 232 EXPORT_SYMBOL_GPL(enclosure_component_register);
 233
 234 /**
 235  * enclosure_add_device - add a device as being part of an enclosure
 236  * @edev:       the enclosure device being added to.
 237  * @num:        the number of the component
 238  * @dev:        the device being added
 239  *
 240  * Declares a real device to reside in slot (or identifier) @num of an
 241  * enclosure.  This will cause the relevant sysfs links to appear.
 242  * This function may also be used to change a device associated with
 243  * an enclosure without having to call enclosure_remove_device() in
 244  * between.
 245  *
 246  * Returns zero on success or an error.
 247  */
 248 int enclosure_add_device(struct enclosure_device *edev, int component,
 249                          struct device *dev)
 250 {
 251         struct enclosure_component *cdev;
 252
 253         if (!edev || component >= edev->components)
 254                 return -EINVAL;
 255
 256         cdev = &edev->component[component];
 257
 258         device_del(&cdev->cdev);
 259         put_device(cdev->dev);
 260         cdev->dev = get_device(dev);
 261         return device_add(&cdev->cdev);
 262 }
 263 EXPORT_SYMBOL_GPL(enclosure_add_device);
 264
 265 /**
 266  * enclosure_remove_device - remove a device from an enclosure
 267  * @edev:       the enclosure device
 268  * @num:        the number of the component to remove
 269  *
 270  * Returns zero on success or an error.
 271  *
 272  */
 273 int enclosure_remove_device(struct enclosure_device *edev, int component)
 274 {
 275         struct enclosure_component *cdev;
 276
 277         if (!edev || component >= edev->components)
 278                 return -EINVAL;
 279
 280         cdev = &edev->component[component];
 281
 282         device_del(&cdev->cdev);
 283         put_device(cdev->dev);
 284         cdev->dev = NULL;
 285         return device_add(&cdev->cdev);
 286 }
 287 EXPORT_SYMBOL_GPL(enclosure_remove_device);
 288
 289 /*
 290  * sysfs pieces below
 291  */
 292
 293 static ssize_t enclosure_show_components(struct device *cdev,
 294                                          struct device_attribute *attr,
 295                                          char *buf)
 296 {
 297         struct enclosure_device *edev = to_enclosure_device(cdev);
 298
 299         return snprintf(buf, 40, "%d\n", edev->components);
 300 }
 301
 302 static struct device_attribute enclosure_attrs[] = {
 303         __ATTR(components, S_IRUGO, enclosure_show_components, NULL),
 304         __ATTR_NULL
 305 };
 306
 307 static struct class enclosure_class = {
 308         .name                   = "enclosure",
 309         .owner                  = THIS_MODULE,
 310         .dev_release            = enclosure_release,
 311         .dev_attrs              = enclosure_attrs,
 312 };
 313
 314 static const char *const enclosure_status [] = {
 315         [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
 316         [ENCLOSURE_STATUS_OK] = "OK",
 317         [ENCLOSURE_STATUS_CRITICAL] = "critical",
 318         [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
 319         [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
 320         [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
 321         [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
 322         [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
 323 };
 324
 325 static const char *const enclosure_type [] = {
 326         [ENCLOSURE_COMPONENT_DEVICE] = "device",
 327         [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
 328 };
 329
 330 static ssize_t get_component_fault(struct device *cdev,
 331                                    struct device_attribute *attr, char *buf)
 332 {
 333         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 334         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 335
 336         if (edev->cb->get_fault)
 337                 edev->cb->get_fault(edev, ecomp);
 338         return snprintf(buf, 40, "%d\n", ecomp->fault);
 339 }
 340
 341 static ssize_t set_component_fault(struct device *cdev,
 342                                    struct device_attribute *attr,
 343                                    const char *buf, size_t count)
 344 {
 345         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 346         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 347         int val = simple_strtoul(buf, NULL, 0);
 348
 349         if (edev->cb->set_fault)
 350                 edev->cb->set_fault(edev, ecomp, val);
 351         return count;
 352 }
 353
 354 static ssize_t get_component_status(struct device *cdev,
 355                                     struct device_attribute *attr,char *buf)
 356 {
 357         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 358         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 359
 360         if (edev->cb->get_status)
 361                 edev->cb->get_status(edev, ecomp);
 362         return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
 363 }
 364
 365 static ssize_t set_component_status(struct device *cdev,
 366                                     struct device_attribute *attr,
 367                                     const char *buf, size_t count)
 368 {
 369         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 370         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 371         int i;
 372
 373         for (i = 0; enclosure_status[i]; i++) {
 374                 if (strncmp(buf, enclosure_status[i],
 375                             strlen(enclosure_status[i])) == 0 &&
 376                     (buf[strlen(enclosure_status[i])] == '\n' ||
 377                      buf[strlen(enclosure_status[i])] == '\0'))
 378                         break;
 379         }
 380
 381         if (enclosure_status[i] && edev->cb->set_status) {
 382                 edev->cb->set_status(edev, ecomp, i);
 383                 return count;
 384         } else
 385                 return -EINVAL;
 386 }
 387
 388 static ssize_t get_component_active(struct device *cdev,
 389                                     struct device_attribute *attr, char *buf)
 390 {
 391         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 392         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 393
 394         if (edev->cb->get_active)
 395                 edev->cb->get_active(edev, ecomp);
 396         return snprintf(buf, 40, "%d\n", ecomp->active);
 397 }
 398
 399 static ssize_t set_component_active(struct device *cdev,
 400                                     struct device_attribute *attr,
 401                                     const char *buf, size_t count)
 402 {
 403         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 404         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 405         int val = simple_strtoul(buf, NULL, 0);
 406
 407         if (edev->cb->set_active)
 408                 edev->cb->set_active(edev, ecomp, val);
 409         return count;
 410 }
 411
 412 static ssize_t get_component_locate(struct device *cdev,
 413                                     struct device_attribute *attr, char *buf)
 414 {
 415         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 416         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 417
 418         if (edev->cb->get_locate)
 419                 edev->cb->get_locate(edev, ecomp);
 420         return snprintf(buf, 40, "%d\n", ecomp->locate);
 421 }
 422
 423 static ssize_t set_component_locate(struct device *cdev,
 424                                     struct device_attribute *attr,
 425                                     const char *buf, size_t count)
 426 {
 427         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 428         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 429         int val = simple_strtoul(buf, NULL, 0);
 430
 431         if (edev->cb->set_locate)
 432                 edev->cb->set_locate(edev, ecomp, val);
 433         return count;
 434 }
 435
 436 static ssize_t get_component_type(struct device *cdev,
 437                                   struct device_attribute *attr, char *buf)
 438 {
 439         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 440
 441         return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
 442 }
 443
 444
 445 static struct device_attribute enclosure_component_attrs[] = {
 446         __ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
 447                set_component_fault),
 448         __ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
 449                set_component_status),
 450         __ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
 451                set_component_active),
 452         __ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
 453                set_component_locate),
 454         __ATTR(type, S_IRUGO, get_component_type, NULL),
 455         __ATTR_NULL
 456 };
 457
 458 static struct class enclosure_component_class =  {
 459         .name                   = "enclosure_component",
 460         .owner                  = THIS_MODULE,
 461         .dev_attrs      = enclosure_component_attrs,
 462         .dev_release            = enclosure_component_release,
 463 };
 464
 465 static int __init enclosure_init(void)
 466 {
 467         int err;
 468
 469         err = class_register(&enclosure_class);
 470         if (err)
 471                 return err;
 472         err = class_register(&enclosure_component_class);
 473         if (err)
 474                 goto err_out;
 475
 476         return 0;
 477  err_out:
 478         class_unregister(&enclosure_class);
 479
 480         return err;
 481 }
 482
 483 static void __exit enclosure_exit(void)
 484 {
 485         class_unregister(&enclosure_component_class);
 486         class_unregister(&enclosure_class);
 487 }
 488
 489 module_init(enclosure_init);
 490 module_exit(enclosure_exit);
 491
 492 MODULE_AUTHOR("James Bottomley");
 493 MODULE_DESCRIPTION("Enclosure Services");
 494 MODULE_LICENSE("GPL v2");