drivers/base/sys.c

   1 /*
   2  * sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
   3  *
   4  * Copyright (c) 2002-3 Patrick Mochel
   5  *               2002-3 Open Source Development Lab
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  * This exports a 'system' bus type.
  10  * By default, a 'sys' bus gets added to the root of the system. There will
  11  * always be core system devices. Devices can use sysdev_register() to
  12  * add themselves as children of the system bus.
  13  */
  14
  15 #include <linux/config.h>
  16 #include <linux/sysdev.h>
  17 #include <linux/err.h>
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/slab.h>
  22 #include <linux/string.h>
  23 #include <linux/pm.h>
  24 #include <linux/device.h>
  25 #include <asm/semaphore.h>
  26
  27 #include "base.h"
  28
  29 extern struct subsystem devices_subsys;
  30
  31 #define to_sysdev(k) container_of(k, struct sys_device, kobj)
  32 #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
  33
  34
  35 static ssize_t
  36 sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
  37 {
  38         struct sys_device * sysdev = to_sysdev(kobj);
  39         struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
  40
  41         if (sysdev_attr->show)
  42                 return sysdev_attr->show(sysdev, buffer);
  43         return -EIO;
  44 }
  45
  46
  47 static ssize_t
  48 sysdev_store(struct kobject * kobj, struct attribute * attr,
  49              const char * buffer, size_t count)
  50 {
  51         struct sys_device * sysdev = to_sysdev(kobj);
  52         struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
  53
  54         if (sysdev_attr->store)
  55                 return sysdev_attr->store(sysdev, buffer, count);
  56         return -EIO;
  57 }
  58
  59 static struct sysfs_ops sysfs_ops = {
  60         .show   = sysdev_show,
  61         .store  = sysdev_store,
  62 };
  63
  64 static struct kobj_type ktype_sysdev = {
  65         .sysfs_ops      = &sysfs_ops,
  66 };
  67
  68
  69 int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
  70 {
  71         return sysfs_create_file(&s->kobj, &a->attr);
  72 }
  73
  74
  75 void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
  76 {
  77         sysfs_remove_file(&s->kobj, &a->attr);
  78 }
  79
  80 EXPORT_SYMBOL_GPL(sysdev_create_file);
  81 EXPORT_SYMBOL_GPL(sysdev_remove_file);
  82
  83 #define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
  84 #define to_sysdev_class_attr(a) container_of(a, \
  85         struct sysdev_class_attribute, attr)
  86
  87 static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
  88                                  char *buffer)
  89 {
  90         struct sysdev_class * class = to_sysdev_class(kobj);
  91         struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
  92
  93         if (class_attr->show)
  94                 return class_attr->show(class, buffer);
  95         return -EIO;
  96 }
  97
  98 static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
  99                                   const char *buffer, size_t count)
 100 {
 101         struct sysdev_class * class = to_sysdev_class(kobj);
 102         struct sysdev_class_attribute * class_attr = to_sysdev_class_attr(attr);
 103
 104         if (class_attr->store)
 105                 return class_attr->store(class, buffer, count);
 106         return -EIO;
 107 }
 108
 109 static struct sysfs_ops sysfs_class_ops = {
 110         .show   = sysdev_class_show,
 111         .store  = sysdev_class_store,
 112 };
 113
 114 static struct kobj_type ktype_sysdev_class = {
 115         .sysfs_ops      = &sysfs_class_ops,
 116 };
 117
 118 int sysdev_class_create_file(struct sysdev_class *c,
 119                              struct sysdev_class_attribute *a)
 120 {
 121         return sysfs_create_file(&c->kset.kobj, &a->attr);
 122 }
 123 EXPORT_SYMBOL_GPL(sysdev_class_create_file);
 124
 125 void sysdev_class_remove_file(struct sysdev_class *c,
 126                               struct sysdev_class_attribute *a)
 127 {
 128         sysfs_remove_file(&c->kset.kobj, &a->attr);
 129 }
 130 EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
 131
 132 /*
 133  * declare system_subsys
 134  */
 135 static decl_subsys(system, &ktype_sysdev_class, NULL);
 136
 137 int sysdev_class_register(struct sysdev_class * cls)
 138 {
 139         pr_debug("Registering sysdev class '%s'\n",
 140                  kobject_name(&cls->kset.kobj));
 141         INIT_LIST_HEAD(&cls->drivers);
 142         cls->kset.subsys = &system_subsys;
 143         kset_set_kset_s(cls, system_subsys);
 144         return kset_register(&cls->kset);
 145 }
 146
 147 void sysdev_class_unregister(struct sysdev_class * cls)
 148 {
 149         pr_debug("Unregistering sysdev class '%s'\n",
 150                  kobject_name(&cls->kset.kobj));
 151         kset_unregister(&cls->kset);
 152 }
 153
 154 EXPORT_SYMBOL_GPL(sysdev_class_register);
 155 EXPORT_SYMBOL_GPL(sysdev_class_unregister);
 156
 157
 158 static LIST_HEAD(sysdev_drivers);
 159 static DECLARE_MUTEX(sysdev_drivers_lock);
 160
 161 /**
 162  *      sysdev_driver_register - Register auxillary driver
 163  *      @cls:   Device class driver belongs to.
 164  *      @drv:   Driver.
 165  *
 166  *      If @cls is valid, then @drv is inserted into @cls->drivers to be
 167  *      called on each operation on devices of that class. The refcount
 168  *      of @cls is incremented.
 169  *      Otherwise, @drv is inserted into sysdev_drivers, and called for
 170  *      each device.
 171  */
 172
 173 int sysdev_driver_register(struct sysdev_class * cls,
 174                            struct sysdev_driver * drv)
 175 {
 176         down(&sysdev_drivers_lock);
 177         if (cls && kset_get(&cls->kset)) {
 178                 list_add_tail(&drv->entry, &cls->drivers);
 179
 180                 /* If devices of this class already exist, tell the driver */
 181                 if (drv->add) {
 182                         struct sys_device *dev;
 183                         list_for_each_entry(dev, &cls->kset.list, kobj.entry)
 184                                 drv->add(dev);
 185                 }
 186         } else
 187                 list_add_tail(&drv->entry, &sysdev_drivers);
 188         up(&sysdev_drivers_lock);
 189         return 0;
 190 }
 191
 192
 193 /**
 194  *      sysdev_driver_unregister - Remove an auxillary driver.
 195  *      @cls:   Class driver belongs to.
 196  *      @drv:   Driver.
 197  */
 198 void sysdev_driver_unregister(struct sysdev_class * cls,
 199                               struct sysdev_driver * drv)
 200 {
 201         down(&sysdev_drivers_lock);
 202         list_del_init(&drv->entry);
 203         if (cls) {
 204                 if (drv->remove) {
 205                         struct sys_device *dev;
 206                         list_for_each_entry(dev, &cls->kset.list, kobj.entry)
 207                                 drv->remove(dev);
 208                 }
 209                 kset_put(&cls->kset);
 210         }
 211         up(&sysdev_drivers_lock);
 212 }
 213
 214 EXPORT_SYMBOL_GPL(sysdev_driver_register);
 215 EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
 216
 217
 218
 219 /**
 220  *      sysdev_register - add a system device to the tree
 221  *      @sysdev:        device in question
 222  *
 223  */
 224 int sysdev_register(struct sys_device * sysdev)
 225 {
 226         int error;
 227         struct sysdev_class * cls = sysdev->cls;
 228
 229         if (!cls)
 230                 return -EINVAL;
 231
 232         /* Make sure the kset is set */
 233         sysdev->kobj.kset = &cls->kset;
 234
 235         /* But make sure we point to the right type for sysfs translation */
 236         sysdev->kobj.ktype = &ktype_sysdev;
 237         error = kobject_set_name(&sysdev->kobj, "%s%d",
 238                          kobject_name(&cls->kset.kobj), sysdev->id);
 239         if (error)
 240                 return error;
 241
 242         pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
 243
 244         /* Register the object */
 245         error = kobject_register(&sysdev->kobj);
 246
 247         if (!error) {
 248                 struct sysdev_driver * drv;
 249
 250                 down(&sysdev_drivers_lock);
 251                 /* Generic notification is implicit, because it's that
 252                  * code that should have called us.
 253                  */
 254
 255                 /* Notify global drivers */
 256                 list_for_each_entry(drv, &sysdev_drivers, entry) {
 257                         if (drv->add)
 258                                 drv->add(sysdev);
 259                 }
 260
 261                 /* Notify class auxillary drivers */
 262                 list_for_each_entry(drv, &cls->drivers, entry) {
 263                         if (drv->add)
 264                                 drv->add(sysdev);
 265                 }
 266                 up(&sysdev_drivers_lock);
 267         }
 268         return error;
 269 }
 270
 271 void sysdev_unregister(struct sys_device * sysdev)
 272 {
 273         struct sysdev_driver * drv;
 274
 275         down(&sysdev_drivers_lock);
 276         list_for_each_entry(drv, &sysdev_drivers, entry) {
 277                 if (drv->remove)
 278                         drv->remove(sysdev);
 279         }
 280
 281         list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
 282                 if (drv->remove)
 283                         drv->remove(sysdev);
 284         }
 285         up(&sysdev_drivers_lock);
 286
 287         kobject_unregister(&sysdev->kobj);
 288 }
 289
 290
 291
 292 /**
 293  *      sysdev_shutdown - Shut down all system devices.
 294  *
 295  *      Loop over each class of system devices, and the devices in each
 296  *      of those classes. For each device, we call the shutdown method for
 297  *      each driver registered for the device - the globals, the auxillaries,
 298  *      and the class driver.
 299  *
 300  *      Note: The list is iterated in reverse order, so that we shut down
 301  *      child devices before we shut down thier parents. The list ordering
 302  *      is guaranteed by virtue of the fact that child devices are registered
 303  *      after their parents.
 304  */
 305
 306 void sysdev_shutdown(void)
 307 {
 308         struct sysdev_class * cls;
 309
 310         pr_debug("Shutting Down System Devices\n");
 311
 312         down(&sysdev_drivers_lock);
 313         list_for_each_entry_reverse(cls, &system_subsys.kset.list,
 314                                     kset.kobj.entry) {
 315                 struct sys_device * sysdev;
 316
 317                 pr_debug("Shutting down type '%s':\n",
 318                          kobject_name(&cls->kset.kobj));
 319
 320                 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
 321                         struct sysdev_driver * drv;
 322                         pr_debug(" %s\n", kobject_name(&sysdev->kobj));
 323
 324                         /* Call global drivers first. */
 325                         list_for_each_entry(drv, &sysdev_drivers, entry) {
 326                                 if (drv->shutdown)
 327                                         drv->shutdown(sysdev);
 328                         }
 329
 330                         /* Call auxillary drivers next. */
 331                         list_for_each_entry(drv, &cls->drivers, entry) {
 332                                 if (drv->shutdown)
 333                                         drv->shutdown(sysdev);
 334                         }
 335
 336                         /* Now call the generic one */
 337                         if (cls->shutdown)
 338                                 cls->shutdown(sysdev);
 339                 }
 340         }
 341         up(&sysdev_drivers_lock);
 342 }
 343
 344 static void __sysdev_resume(struct sys_device *dev)
 345 {
 346         struct sysdev_class *cls = dev->cls;
 347         struct sysdev_driver *drv;
 348
 349         /* First, call the class-specific one */
 350         if (cls->resume)
 351                 cls->resume(dev);
 352
 353         /* Call auxillary drivers next. */
 354         list_for_each_entry(drv, &cls->drivers, entry) {
 355                 if (drv->resume)
 356                         drv->resume(dev);
 357         }
 358
 359         /* Call global drivers. */
 360         list_for_each_entry(drv, &sysdev_drivers, entry) {
 361                 if (drv->resume)
 362                         drv->resume(dev);
 363         }
 364 }
 365
 366 /**
 367  *      sysdev_suspend - Suspend all system devices.
 368  *      @state:         Power state to enter.
 369  *
 370  *      We perform an almost identical operation as sys_device_shutdown()
 371  *      above, though calling ->suspend() instead. Interrupts are disabled
 372  *      when this called. Devices are responsible for both saving state and
 373  *      quiescing or powering down the device.
 374  *
 375  *      This is only called by the device PM core, so we let them handle
 376  *      all synchronization.
 377  */
 378
 379 int sysdev_suspend(pm_message_t state)
 380 {
 381         struct sysdev_class * cls;
 382         struct sys_device *sysdev, *err_dev;
 383         struct sysdev_driver *drv, *err_drv;
 384         int ret;
 385
 386         pr_debug("Suspending System Devices\n");
 387
 388         list_for_each_entry_reverse(cls, &system_subsys.kset.list,
 389                                     kset.kobj.entry) {
 390
 391                 pr_debug("Suspending type '%s':\n",
 392                          kobject_name(&cls->kset.kobj));
 393
 394                 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
 395                         pr_debug(" %s\n", kobject_name(&sysdev->kobj));
 396
 397                         /* Call global drivers first. */
 398                         list_for_each_entry(drv, &sysdev_drivers, entry) {
 399                                 if (drv->suspend) {
 400                                         ret = drv->suspend(sysdev, state);
 401                                         if (ret)
 402                                                 goto gbl_driver;
 403                                 }
 404                         }
 405
 406                         /* Call auxillary drivers next. */
 407                         list_for_each_entry(drv, &cls->drivers, entry) {
 408                                 if (drv->suspend) {
 409                                         ret = drv->suspend(sysdev, state);
 410                                         if (ret)
 411                                                 goto aux_driver;
 412                                 }
 413                         }
 414
 415                         /* Now call the generic one */
 416                         if (cls->suspend) {
 417                                 ret = cls->suspend(sysdev, state);
 418                                 if (ret)
 419                                         goto cls_driver;
 420                         }
 421                 }
 422         }
 423         return 0;
 424         /* resume current sysdev */
 425 cls_driver:
 426         drv = NULL;
 427         printk(KERN_ERR "Class suspend failed for %s\n",
 428                 kobject_name(&sysdev->kobj));
 429
 430 aux_driver:
 431         if (drv)
 432                 printk(KERN_ERR "Class driver suspend failed for %s\n",
 433                                 kobject_name(&sysdev->kobj));
 434         list_for_each_entry(err_drv, &cls->drivers, entry) {
 435                 if (err_drv == drv)
 436                         break;
 437                 if (err_drv->resume)
 438                         err_drv->resume(sysdev);
 439         }
 440         drv = NULL;
 441
 442 gbl_driver:
 443         if (drv)
 444                 printk(KERN_ERR "sysdev driver suspend failed for %s\n",
 445                                 kobject_name(&sysdev->kobj));
 446         list_for_each_entry(err_drv, &sysdev_drivers, entry) {
 447                 if (err_drv == drv)
 448                         break;
 449                 if (err_drv->resume)
 450                         err_drv->resume(sysdev);
 451         }
 452         /* resume other sysdevs in current class */
 453         list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
 454                 if (err_dev == sysdev)
 455                         break;
 456                 pr_debug(" %s\n", kobject_name(&err_dev->kobj));
 457                 __sysdev_resume(err_dev);
 458         }
 459
 460         /* resume other classes */
 461         list_for_each_entry_continue(cls, &system_subsys.kset.list,
 462                                         kset.kobj.entry) {
 463                 list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
 464                         pr_debug(" %s\n", kobject_name(&err_dev->kobj));
 465                         __sysdev_resume(err_dev);
 466                 }
 467         }
 468         return ret;
 469 }
 470
 471
 472 /**
 473  *      sysdev_resume - Bring system devices back to life.
 474  *
 475  *      Similar to sys_device_suspend(), but we iterate the list forwards
 476  *      to guarantee that parent devices are resumed before their children.
 477  *
 478  *      Note: Interrupts are disabled when called.
 479  */
 480
 481 int sysdev_resume(void)
 482 {
 483         struct sysdev_class * cls;
 484
 485         pr_debug("Resuming System Devices\n");
 486
 487         list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) {
 488                 struct sys_device * sysdev;
 489
 490                 pr_debug("Resuming type '%s':\n",
 491                          kobject_name(&cls->kset.kobj));
 492
 493                 list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
 494                         pr_debug(" %s\n", kobject_name(&sysdev->kobj));
 495
 496                         __sysdev_resume(sysdev);
 497                 }
 498         }
 499         return 0;
 500 }
 501
 502
 503 int __init system_bus_init(void)
 504 {
 505         system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
 506         return subsystem_register(&system_subsys);
 507 }
 508
 509 EXPORT_SYMBOL_GPL(sysdev_register);
 510 EXPORT_SYMBOL_GPL(sysdev_unregister);