Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 24 | |
| 25 | extern struct subsystem devices_subsys; |
| 26 | |
| 27 | #define to_sysdev(k) container_of(k, struct sys_device, kobj) |
| 28 | #define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr) |
| 29 | |
| 30 | |
| 31 | static ssize_t |
| 32 | sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer) |
| 33 | { |
| 34 | struct sys_device * sysdev = to_sysdev(kobj); |
| 35 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); |
| 36 | |
| 37 | if (sysdev_attr->show) |
| 38 | return sysdev_attr->show(sysdev, buffer); |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | |
| 43 | static ssize_t |
| 44 | sysdev_store(struct kobject * kobj, struct attribute * attr, |
| 45 | const char * buffer, size_t count) |
| 46 | { |
| 47 | struct sys_device * sysdev = to_sysdev(kobj); |
| 48 | struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr); |
| 49 | |
| 50 | if (sysdev_attr->store) |
| 51 | return sysdev_attr->store(sysdev, buffer, count); |
| 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | static struct sysfs_ops sysfs_ops = { |
| 56 | .show = sysdev_show, |
| 57 | .store = sysdev_store, |
| 58 | }; |
| 59 | |
| 60 | static struct kobj_type ktype_sysdev = { |
| 61 | .sysfs_ops = &sysfs_ops, |
| 62 | }; |
| 63 | |
| 64 | |
| 65 | int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a) |
| 66 | { |
| 67 | return sysfs_create_file(&s->kobj, &a->attr); |
| 68 | } |
| 69 | |
| 70 | |
| 71 | void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a) |
| 72 | { |
| 73 | sysfs_remove_file(&s->kobj, &a->attr); |
| 74 | } |
| 75 | |
| 76 | EXPORT_SYMBOL_GPL(sysdev_create_file); |
| 77 | EXPORT_SYMBOL_GPL(sysdev_remove_file); |
| 78 | |
| 79 | /* |
| 80 | * declare system_subsys |
| 81 | */ |
| 82 | static decl_subsys(system, &ktype_sysdev, NULL); |
| 83 | |
| 84 | int sysdev_class_register(struct sysdev_class * cls) |
| 85 | { |
| 86 | pr_debug("Registering sysdev class '%s'\n", |
| 87 | kobject_name(&cls->kset.kobj)); |
| 88 | INIT_LIST_HEAD(&cls->drivers); |
| 89 | cls->kset.subsys = &system_subsys; |
| 90 | kset_set_kset_s(cls, system_subsys); |
| 91 | return kset_register(&cls->kset); |
| 92 | } |
| 93 | |
| 94 | void sysdev_class_unregister(struct sysdev_class * cls) |
| 95 | { |
| 96 | pr_debug("Unregistering sysdev class '%s'\n", |
| 97 | kobject_name(&cls->kset.kobj)); |
| 98 | kset_unregister(&cls->kset); |
| 99 | } |
| 100 | |
| 101 | EXPORT_SYMBOL_GPL(sysdev_class_register); |
| 102 | EXPORT_SYMBOL_GPL(sysdev_class_unregister); |
| 103 | |
| 104 | |
| 105 | static LIST_HEAD(sysdev_drivers); |
| 106 | static DECLARE_MUTEX(sysdev_drivers_lock); |
| 107 | |
| 108 | /** |
| 109 | * sysdev_driver_register - Register auxillary driver |
| 110 | * @cls: Device class driver belongs to. |
| 111 | * @drv: Driver. |
| 112 | * |
| 113 | * If @cls is valid, then @drv is inserted into @cls->drivers to be |
| 114 | * called on each operation on devices of that class. The refcount |
| 115 | * of @cls is incremented. |
| 116 | * Otherwise, @drv is inserted into sysdev_drivers, and called for |
| 117 | * each device. |
| 118 | */ |
| 119 | |
| 120 | int sysdev_driver_register(struct sysdev_class * cls, |
| 121 | struct sysdev_driver * drv) |
| 122 | { |
| 123 | down(&sysdev_drivers_lock); |
| 124 | if (cls && kset_get(&cls->kset)) { |
| 125 | list_add_tail(&drv->entry, &cls->drivers); |
| 126 | |
| 127 | /* If devices of this class already exist, tell the driver */ |
| 128 | if (drv->add) { |
| 129 | struct sys_device *dev; |
| 130 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) |
| 131 | drv->add(dev); |
| 132 | } |
| 133 | } else |
| 134 | list_add_tail(&drv->entry, &sysdev_drivers); |
| 135 | up(&sysdev_drivers_lock); |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | |
| 140 | /** |
| 141 | * sysdev_driver_unregister - Remove an auxillary driver. |
| 142 | * @cls: Class driver belongs to. |
| 143 | * @drv: Driver. |
| 144 | */ |
| 145 | void sysdev_driver_unregister(struct sysdev_class * cls, |
| 146 | struct sysdev_driver * drv) |
| 147 | { |
| 148 | down(&sysdev_drivers_lock); |
| 149 | list_del_init(&drv->entry); |
| 150 | if (cls) { |
| 151 | if (drv->remove) { |
| 152 | struct sys_device *dev; |
| 153 | list_for_each_entry(dev, &cls->kset.list, kobj.entry) |
| 154 | drv->remove(dev); |
| 155 | } |
| 156 | kset_put(&cls->kset); |
| 157 | } |
| 158 | up(&sysdev_drivers_lock); |
| 159 | } |
| 160 | |
| 161 | EXPORT_SYMBOL_GPL(sysdev_driver_register); |
| 162 | EXPORT_SYMBOL_GPL(sysdev_driver_unregister); |
| 163 | |
| 164 | |
| 165 | |
| 166 | /** |
| 167 | * sysdev_register - add a system device to the tree |
| 168 | * @sysdev: device in question |
| 169 | * |
| 170 | */ |
| 171 | int sysdev_register(struct sys_device * sysdev) |
| 172 | { |
| 173 | int error; |
| 174 | struct sysdev_class * cls = sysdev->cls; |
| 175 | |
| 176 | if (!cls) |
| 177 | return -EINVAL; |
| 178 | |
| 179 | /* Make sure the kset is set */ |
| 180 | sysdev->kobj.kset = &cls->kset; |
| 181 | |
| 182 | /* But make sure we point to the right type for sysfs translation */ |
| 183 | sysdev->kobj.ktype = &ktype_sysdev; |
| 184 | error = kobject_set_name(&sysdev->kobj, "%s%d", |
| 185 | kobject_name(&cls->kset.kobj), sysdev->id); |
| 186 | if (error) |
| 187 | return error; |
| 188 | |
| 189 | pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj)); |
| 190 | |
| 191 | /* Register the object */ |
| 192 | error = kobject_register(&sysdev->kobj); |
| 193 | |
| 194 | if (!error) { |
| 195 | struct sysdev_driver * drv; |
| 196 | |
| 197 | down(&sysdev_drivers_lock); |
| 198 | /* Generic notification is implicit, because it's that |
| 199 | * code that should have called us. |
| 200 | */ |
| 201 | |
| 202 | /* Notify global drivers */ |
| 203 | list_for_each_entry(drv, &sysdev_drivers, entry) { |
| 204 | if (drv->add) |
| 205 | drv->add(sysdev); |
| 206 | } |
| 207 | |
| 208 | /* Notify class auxillary drivers */ |
| 209 | list_for_each_entry(drv, &cls->drivers, entry) { |
| 210 | if (drv->add) |
| 211 | drv->add(sysdev); |
| 212 | } |
| 213 | up(&sysdev_drivers_lock); |
| 214 | } |
| 215 | return error; |
| 216 | } |
| 217 | |
| 218 | void sysdev_unregister(struct sys_device * sysdev) |
| 219 | { |
| 220 | struct sysdev_driver * drv; |
| 221 | |
| 222 | down(&sysdev_drivers_lock); |
| 223 | list_for_each_entry(drv, &sysdev_drivers, entry) { |
| 224 | if (drv->remove) |
| 225 | drv->remove(sysdev); |
| 226 | } |
| 227 | |
| 228 | list_for_each_entry(drv, &sysdev->cls->drivers, entry) { |
| 229 | if (drv->remove) |
| 230 | drv->remove(sysdev); |
| 231 | } |
| 232 | up(&sysdev_drivers_lock); |
| 233 | |
| 234 | kobject_unregister(&sysdev->kobj); |
| 235 | } |
| 236 | |
| 237 | |
| 238 | |
| 239 | /** |
| 240 | * sysdev_shutdown - Shut down all system devices. |
| 241 | * |
| 242 | * Loop over each class of system devices, and the devices in each |
| 243 | * of those classes. For each device, we call the shutdown method for |
| 244 | * each driver registered for the device - the globals, the auxillaries, |
| 245 | * and the class driver. |
| 246 | * |
| 247 | * Note: The list is iterated in reverse order, so that we shut down |
| 248 | * child devices before we shut down thier parents. The list ordering |
| 249 | * is guaranteed by virtue of the fact that child devices are registered |
| 250 | * after their parents. |
| 251 | */ |
| 252 | |
| 253 | void sysdev_shutdown(void) |
| 254 | { |
| 255 | struct sysdev_class * cls; |
| 256 | |
| 257 | pr_debug("Shutting Down System Devices\n"); |
| 258 | |
| 259 | down(&sysdev_drivers_lock); |
| 260 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, |
| 261 | kset.kobj.entry) { |
| 262 | struct sys_device * sysdev; |
| 263 | |
| 264 | pr_debug("Shutting down type '%s':\n", |
| 265 | kobject_name(&cls->kset.kobj)); |
| 266 | |
| 267 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { |
| 268 | struct sysdev_driver * drv; |
| 269 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
| 270 | |
| 271 | /* Call global drivers first. */ |
| 272 | list_for_each_entry(drv, &sysdev_drivers, entry) { |
| 273 | if (drv->shutdown) |
| 274 | drv->shutdown(sysdev); |
| 275 | } |
| 276 | |
| 277 | /* Call auxillary drivers next. */ |
| 278 | list_for_each_entry(drv, &cls->drivers, entry) { |
| 279 | if (drv->shutdown) |
| 280 | drv->shutdown(sysdev); |
| 281 | } |
| 282 | |
| 283 | /* Now call the generic one */ |
| 284 | if (cls->shutdown) |
| 285 | cls->shutdown(sysdev); |
| 286 | } |
| 287 | } |
| 288 | up(&sysdev_drivers_lock); |
| 289 | } |
| 290 | |
| 291 | |
| 292 | /** |
| 293 | * sysdev_suspend - Suspend all system devices. |
| 294 | * @state: Power state to enter. |
| 295 | * |
| 296 | * We perform an almost identical operation as sys_device_shutdown() |
| 297 | * above, though calling ->suspend() instead. Interrupts are disabled |
| 298 | * when this called. Devices are responsible for both saving state and |
| 299 | * quiescing or powering down the device. |
| 300 | * |
| 301 | * This is only called by the device PM core, so we let them handle |
| 302 | * all synchronization. |
| 303 | */ |
| 304 | |
| 305 | int sysdev_suspend(u32 state) |
| 306 | { |
| 307 | struct sysdev_class * cls; |
| 308 | |
| 309 | pr_debug("Suspending System Devices\n"); |
| 310 | |
| 311 | list_for_each_entry_reverse(cls, &system_subsys.kset.list, |
| 312 | kset.kobj.entry) { |
| 313 | struct sys_device * sysdev; |
| 314 | |
| 315 | pr_debug("Suspending type '%s':\n", |
| 316 | kobject_name(&cls->kset.kobj)); |
| 317 | |
| 318 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { |
| 319 | struct sysdev_driver * drv; |
| 320 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
| 321 | |
| 322 | /* Call global drivers first. */ |
| 323 | list_for_each_entry(drv, &sysdev_drivers, entry) { |
| 324 | if (drv->suspend) |
| 325 | drv->suspend(sysdev, state); |
| 326 | } |
| 327 | |
| 328 | /* Call auxillary drivers next. */ |
| 329 | list_for_each_entry(drv, &cls->drivers, entry) { |
| 330 | if (drv->suspend) |
| 331 | drv->suspend(sysdev, state); |
| 332 | } |
| 333 | |
| 334 | /* Now call the generic one */ |
| 335 | if (cls->suspend) |
| 336 | cls->suspend(sysdev, state); |
| 337 | } |
| 338 | } |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | |
| 343 | /** |
| 344 | * sysdev_resume - Bring system devices back to life. |
| 345 | * |
| 346 | * Similar to sys_device_suspend(), but we iterate the list forwards |
| 347 | * to guarantee that parent devices are resumed before their children. |
| 348 | * |
| 349 | * Note: Interrupts are disabled when called. |
| 350 | */ |
| 351 | |
| 352 | int sysdev_resume(void) |
| 353 | { |
| 354 | struct sysdev_class * cls; |
| 355 | |
| 356 | pr_debug("Resuming System Devices\n"); |
| 357 | |
| 358 | list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) { |
| 359 | struct sys_device * sysdev; |
| 360 | |
| 361 | pr_debug("Resuming type '%s':\n", |
| 362 | kobject_name(&cls->kset.kobj)); |
| 363 | |
| 364 | list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) { |
| 365 | struct sysdev_driver * drv; |
| 366 | pr_debug(" %s\n", kobject_name(&sysdev->kobj)); |
| 367 | |
| 368 | /* First, call the class-specific one */ |
| 369 | if (cls->resume) |
| 370 | cls->resume(sysdev); |
| 371 | |
| 372 | /* Call auxillary drivers next. */ |
| 373 | list_for_each_entry(drv, &cls->drivers, entry) { |
| 374 | if (drv->resume) |
| 375 | drv->resume(sysdev); |
| 376 | } |
| 377 | |
| 378 | /* Call global drivers. */ |
| 379 | list_for_each_entry(drv, &sysdev_drivers, entry) { |
| 380 | if (drv->resume) |
| 381 | drv->resume(sysdev); |
| 382 | } |
| 383 | |
| 384 | } |
| 385 | } |
| 386 | return 0; |
| 387 | } |
| 388 | |
| 389 | |
| 390 | int __init system_bus_init(void) |
| 391 | { |
| 392 | system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj; |
| 393 | return subsystem_register(&system_subsys); |
| 394 | } |
| 395 | |
| 396 | EXPORT_SYMBOL_GPL(sysdev_register); |
| 397 | EXPORT_SYMBOL_GPL(sysdev_unregister); |