Rafael J. Wysocki | f721889 | 2011-07-01 22:12:45 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * drivers/base/power/domain.c - Common code related to device power domains. |
| 3 | * |
| 4 | * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. |
| 5 | * |
| 6 | * This file is released under the GPLv2. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/init.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/io.h> |
| 12 | #include <linux/pm_runtime.h> |
| 13 | #include <linux/pm_domain.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/err.h> |
| 16 | |
| 17 | #ifdef CONFIG_PM_RUNTIME |
| 18 | |
| 19 | static void genpd_sd_counter_dec(struct generic_pm_domain *genpd) |
| 20 | { |
| 21 | if (!WARN_ON(genpd->sd_count == 0)) |
| 22 | genpd->sd_count--; |
| 23 | } |
| 24 | |
| 25 | /** |
| 26 | * __pm_genpd_save_device - Save the pre-suspend state of a device. |
| 27 | * @dle: Device list entry of the device to save the state of. |
| 28 | * @genpd: PM domain the device belongs to. |
| 29 | */ |
| 30 | static int __pm_genpd_save_device(struct dev_list_entry *dle, |
| 31 | struct generic_pm_domain *genpd) |
| 32 | { |
| 33 | struct device *dev = dle->dev; |
| 34 | struct device_driver *drv = dev->driver; |
| 35 | int ret = 0; |
| 36 | |
| 37 | if (dle->need_restore) |
| 38 | return 0; |
| 39 | |
| 40 | if (drv && drv->pm && drv->pm->runtime_suspend) { |
| 41 | if (genpd->start_device) |
| 42 | genpd->start_device(dev); |
| 43 | |
| 44 | ret = drv->pm->runtime_suspend(dev); |
| 45 | |
| 46 | if (genpd->stop_device) |
| 47 | genpd->stop_device(dev); |
| 48 | } |
| 49 | |
| 50 | if (!ret) |
| 51 | dle->need_restore = true; |
| 52 | |
| 53 | return ret; |
| 54 | } |
| 55 | |
| 56 | /** |
| 57 | * __pm_genpd_restore_device - Restore the pre-suspend state of a device. |
| 58 | * @dle: Device list entry of the device to restore the state of. |
| 59 | * @genpd: PM domain the device belongs to. |
| 60 | */ |
| 61 | static void __pm_genpd_restore_device(struct dev_list_entry *dle, |
| 62 | struct generic_pm_domain *genpd) |
| 63 | { |
| 64 | struct device *dev = dle->dev; |
| 65 | struct device_driver *drv = dev->driver; |
| 66 | |
| 67 | if (!dle->need_restore) |
| 68 | return; |
| 69 | |
| 70 | if (drv && drv->pm && drv->pm->runtime_resume) { |
| 71 | if (genpd->start_device) |
| 72 | genpd->start_device(dev); |
| 73 | |
| 74 | drv->pm->runtime_resume(dev); |
| 75 | |
| 76 | if (genpd->stop_device) |
| 77 | genpd->stop_device(dev); |
| 78 | } |
| 79 | |
| 80 | dle->need_restore = false; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * pm_genpd_poweroff - Remove power from a given PM domain. |
| 85 | * @genpd: PM domain to power down. |
| 86 | * |
| 87 | * If all of the @genpd's devices have been suspended and all of its subdomains |
| 88 | * have been powered down, run the runtime suspend callbacks provided by all of |
| 89 | * the @genpd's devices' drivers and remove power from @genpd. |
| 90 | */ |
| 91 | static int pm_genpd_poweroff(struct generic_pm_domain *genpd) |
| 92 | { |
| 93 | struct generic_pm_domain *parent; |
| 94 | struct dev_list_entry *dle; |
| 95 | unsigned int not_suspended; |
| 96 | int ret; |
| 97 | |
| 98 | if (genpd->power_is_off) |
| 99 | return 0; |
| 100 | |
| 101 | if (genpd->sd_count > 0) |
| 102 | return -EBUSY; |
| 103 | |
| 104 | not_suspended = 0; |
| 105 | list_for_each_entry(dle, &genpd->dev_list, node) |
| 106 | if (dle->dev->driver && !pm_runtime_suspended(dle->dev)) |
| 107 | not_suspended++; |
| 108 | |
| 109 | if (not_suspended > genpd->in_progress) |
| 110 | return -EBUSY; |
| 111 | |
| 112 | if (genpd->gov && genpd->gov->power_down_ok) { |
| 113 | if (!genpd->gov->power_down_ok(&genpd->domain)) |
| 114 | return -EAGAIN; |
| 115 | } |
| 116 | |
| 117 | list_for_each_entry_reverse(dle, &genpd->dev_list, node) { |
| 118 | ret = __pm_genpd_save_device(dle, genpd); |
| 119 | if (ret) |
| 120 | goto err_dev; |
| 121 | } |
| 122 | |
| 123 | if (genpd->power_off) |
| 124 | genpd->power_off(genpd); |
| 125 | |
| 126 | genpd->power_is_off = true; |
| 127 | |
| 128 | parent = genpd->parent; |
| 129 | if (parent) { |
| 130 | genpd_sd_counter_dec(parent); |
| 131 | if (parent->sd_count == 0) |
| 132 | queue_work(pm_wq, &parent->power_off_work); |
| 133 | } |
| 134 | |
| 135 | return 0; |
| 136 | |
| 137 | err_dev: |
| 138 | list_for_each_entry_continue(dle, &genpd->dev_list, node) |
| 139 | __pm_genpd_restore_device(dle, genpd); |
| 140 | |
| 141 | return ret; |
| 142 | } |
| 143 | |
| 144 | /** |
| 145 | * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. |
| 146 | * @work: Work structure used for scheduling the execution of this function. |
| 147 | */ |
| 148 | static void genpd_power_off_work_fn(struct work_struct *work) |
| 149 | { |
| 150 | struct generic_pm_domain *genpd; |
| 151 | |
| 152 | genpd = container_of(work, struct generic_pm_domain, power_off_work); |
| 153 | |
| 154 | if (genpd->parent) |
| 155 | mutex_lock(&genpd->parent->lock); |
| 156 | mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); |
| 157 | pm_genpd_poweroff(genpd); |
| 158 | mutex_unlock(&genpd->lock); |
| 159 | if (genpd->parent) |
| 160 | mutex_unlock(&genpd->parent->lock); |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. |
| 165 | * @dev: Device to suspend. |
| 166 | * |
| 167 | * Carry out a runtime suspend of a device under the assumption that its |
| 168 | * pm_domain field points to the domain member of an object of type |
| 169 | * struct generic_pm_domain representing a PM domain consisting of I/O devices. |
| 170 | */ |
| 171 | static int pm_genpd_runtime_suspend(struct device *dev) |
| 172 | { |
| 173 | struct generic_pm_domain *genpd; |
| 174 | |
| 175 | dev_dbg(dev, "%s()\n", __func__); |
| 176 | |
| 177 | if (IS_ERR_OR_NULL(dev->pm_domain)) |
| 178 | return -EINVAL; |
| 179 | |
| 180 | genpd = container_of(dev->pm_domain, struct generic_pm_domain, domain); |
| 181 | |
| 182 | if (genpd->parent) |
| 183 | mutex_lock(&genpd->parent->lock); |
| 184 | mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); |
| 185 | |
| 186 | if (genpd->stop_device) { |
| 187 | int ret = genpd->stop_device(dev); |
| 188 | if (ret) |
| 189 | goto out; |
| 190 | } |
| 191 | genpd->in_progress++; |
| 192 | pm_genpd_poweroff(genpd); |
| 193 | genpd->in_progress--; |
| 194 | |
| 195 | out: |
| 196 | mutex_unlock(&genpd->lock); |
| 197 | if (genpd->parent) |
| 198 | mutex_unlock(&genpd->parent->lock); |
| 199 | |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * pm_genpd_poweron - Restore power to a given PM domain and its parents. |
| 205 | * @genpd: PM domain to power up. |
| 206 | * |
| 207 | * Restore power to @genpd and all of its parents so that it is possible to |
| 208 | * resume a device belonging to it. |
| 209 | */ |
| 210 | static int pm_genpd_poweron(struct generic_pm_domain *genpd) |
| 211 | { |
| 212 | int ret = 0; |
| 213 | |
| 214 | start: |
| 215 | if (genpd->parent) |
| 216 | mutex_lock(&genpd->parent->lock); |
| 217 | mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); |
| 218 | |
| 219 | if (!genpd->power_is_off) |
| 220 | goto out; |
| 221 | |
| 222 | if (genpd->parent && genpd->parent->power_is_off) { |
| 223 | mutex_unlock(&genpd->lock); |
| 224 | mutex_unlock(&genpd->parent->lock); |
| 225 | |
| 226 | ret = pm_genpd_poweron(genpd->parent); |
| 227 | if (ret) |
| 228 | return ret; |
| 229 | |
| 230 | goto start; |
| 231 | } |
| 232 | |
| 233 | if (genpd->power_on) { |
| 234 | int ret = genpd->power_on(genpd); |
| 235 | if (ret) |
| 236 | goto out; |
| 237 | } |
| 238 | |
| 239 | genpd->power_is_off = false; |
| 240 | if (genpd->parent) |
| 241 | genpd->parent->sd_count++; |
| 242 | |
| 243 | out: |
| 244 | mutex_unlock(&genpd->lock); |
| 245 | if (genpd->parent) |
| 246 | mutex_unlock(&genpd->parent->lock); |
| 247 | |
| 248 | return ret; |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. |
| 253 | * @dev: Device to resume. |
| 254 | * |
| 255 | * Carry out a runtime resume of a device under the assumption that its |
| 256 | * pm_domain field points to the domain member of an object of type |
| 257 | * struct generic_pm_domain representing a PM domain consisting of I/O devices. |
| 258 | */ |
| 259 | static int pm_genpd_runtime_resume(struct device *dev) |
| 260 | { |
| 261 | struct generic_pm_domain *genpd; |
| 262 | struct dev_list_entry *dle; |
| 263 | int ret; |
| 264 | |
| 265 | dev_dbg(dev, "%s()\n", __func__); |
| 266 | |
| 267 | if (IS_ERR_OR_NULL(dev->pm_domain)) |
| 268 | return -EINVAL; |
| 269 | |
| 270 | genpd = container_of(dev->pm_domain, struct generic_pm_domain, domain); |
| 271 | |
| 272 | ret = pm_genpd_poweron(genpd); |
| 273 | if (ret) |
| 274 | return ret; |
| 275 | |
| 276 | mutex_lock(&genpd->lock); |
| 277 | |
| 278 | list_for_each_entry(dle, &genpd->dev_list, node) { |
| 279 | if (dle->dev == dev) { |
| 280 | __pm_genpd_restore_device(dle, genpd); |
| 281 | break; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | if (genpd->start_device) |
| 286 | genpd->start_device(dev); |
| 287 | |
| 288 | mutex_unlock(&genpd->lock); |
| 289 | |
| 290 | return 0; |
| 291 | } |
| 292 | |
| 293 | #else |
| 294 | |
| 295 | static inline void genpd_power_off_work_fn(struct work_struct *work) {} |
| 296 | |
| 297 | #define pm_genpd_runtime_suspend NULL |
| 298 | #define pm_genpd_runtime_resume NULL |
| 299 | |
| 300 | #endif /* CONFIG_PM_RUNTIME */ |
| 301 | |
| 302 | /** |
| 303 | * pm_genpd_add_device - Add a device to an I/O PM domain. |
| 304 | * @genpd: PM domain to add the device to. |
| 305 | * @dev: Device to be added. |
| 306 | */ |
| 307 | int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev) |
| 308 | { |
| 309 | struct dev_list_entry *dle; |
| 310 | int ret = 0; |
| 311 | |
| 312 | dev_dbg(dev, "%s()\n", __func__); |
| 313 | |
| 314 | if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) |
| 315 | return -EINVAL; |
| 316 | |
| 317 | mutex_lock(&genpd->lock); |
| 318 | |
| 319 | if (genpd->power_is_off) { |
| 320 | ret = -EINVAL; |
| 321 | goto out; |
| 322 | } |
| 323 | |
| 324 | list_for_each_entry(dle, &genpd->dev_list, node) |
| 325 | if (dle->dev == dev) { |
| 326 | ret = -EINVAL; |
| 327 | goto out; |
| 328 | } |
| 329 | |
| 330 | dle = kzalloc(sizeof(*dle), GFP_KERNEL); |
| 331 | if (!dle) { |
| 332 | ret = -ENOMEM; |
| 333 | goto out; |
| 334 | } |
| 335 | |
| 336 | dle->dev = dev; |
| 337 | dle->need_restore = false; |
| 338 | list_add_tail(&dle->node, &genpd->dev_list); |
| 339 | |
| 340 | spin_lock_irq(&dev->power.lock); |
| 341 | dev->pm_domain = &genpd->domain; |
| 342 | spin_unlock_irq(&dev->power.lock); |
| 343 | |
| 344 | out: |
| 345 | mutex_unlock(&genpd->lock); |
| 346 | |
| 347 | return ret; |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * pm_genpd_remove_device - Remove a device from an I/O PM domain. |
| 352 | * @genpd: PM domain to remove the device from. |
| 353 | * @dev: Device to be removed. |
| 354 | */ |
| 355 | int pm_genpd_remove_device(struct generic_pm_domain *genpd, |
| 356 | struct device *dev) |
| 357 | { |
| 358 | struct dev_list_entry *dle; |
| 359 | int ret = -EINVAL; |
| 360 | |
| 361 | dev_dbg(dev, "%s()\n", __func__); |
| 362 | |
| 363 | if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) |
| 364 | return -EINVAL; |
| 365 | |
| 366 | mutex_lock(&genpd->lock); |
| 367 | |
| 368 | list_for_each_entry(dle, &genpd->dev_list, node) { |
| 369 | if (dle->dev != dev) |
| 370 | continue; |
| 371 | |
| 372 | spin_lock_irq(&dev->power.lock); |
| 373 | dev->pm_domain = NULL; |
| 374 | spin_unlock_irq(&dev->power.lock); |
| 375 | |
| 376 | list_del(&dle->node); |
| 377 | kfree(dle); |
| 378 | |
| 379 | ret = 0; |
| 380 | break; |
| 381 | } |
| 382 | |
| 383 | mutex_unlock(&genpd->lock); |
| 384 | |
| 385 | return ret; |
| 386 | } |
| 387 | |
| 388 | /** |
| 389 | * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. |
| 390 | * @genpd: Master PM domain to add the subdomain to. |
| 391 | * @new_subdomain: Subdomain to be added. |
| 392 | */ |
| 393 | int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, |
| 394 | struct generic_pm_domain *new_subdomain) |
| 395 | { |
| 396 | struct generic_pm_domain *subdomain; |
| 397 | int ret = 0; |
| 398 | |
| 399 | if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain)) |
| 400 | return -EINVAL; |
| 401 | |
| 402 | mutex_lock(&genpd->lock); |
| 403 | |
| 404 | if (genpd->power_is_off && !new_subdomain->power_is_off) { |
| 405 | ret = -EINVAL; |
| 406 | goto out; |
| 407 | } |
| 408 | |
| 409 | list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { |
| 410 | if (subdomain == new_subdomain) { |
| 411 | ret = -EINVAL; |
| 412 | goto out; |
| 413 | } |
| 414 | } |
| 415 | |
| 416 | mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING); |
| 417 | |
| 418 | list_add_tail(&new_subdomain->sd_node, &genpd->sd_list); |
| 419 | new_subdomain->parent = genpd; |
| 420 | if (!subdomain->power_is_off) |
| 421 | genpd->sd_count++; |
| 422 | |
| 423 | mutex_unlock(&new_subdomain->lock); |
| 424 | |
| 425 | out: |
| 426 | mutex_unlock(&genpd->lock); |
| 427 | |
| 428 | return ret; |
| 429 | } |
| 430 | |
| 431 | /** |
| 432 | * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. |
| 433 | * @genpd: Master PM domain to remove the subdomain from. |
| 434 | * @target: Subdomain to be removed. |
| 435 | */ |
| 436 | int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, |
| 437 | struct generic_pm_domain *target) |
| 438 | { |
| 439 | struct generic_pm_domain *subdomain; |
| 440 | int ret = -EINVAL; |
| 441 | |
| 442 | if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(target)) |
| 443 | return -EINVAL; |
| 444 | |
| 445 | mutex_lock(&genpd->lock); |
| 446 | |
| 447 | list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { |
| 448 | if (subdomain != target) |
| 449 | continue; |
| 450 | |
| 451 | mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); |
| 452 | |
| 453 | list_del(&subdomain->sd_node); |
| 454 | subdomain->parent = NULL; |
| 455 | if (!subdomain->power_is_off) |
| 456 | genpd_sd_counter_dec(genpd); |
| 457 | |
| 458 | mutex_unlock(&subdomain->lock); |
| 459 | |
| 460 | ret = 0; |
| 461 | break; |
| 462 | } |
| 463 | |
| 464 | mutex_unlock(&genpd->lock); |
| 465 | |
| 466 | return ret; |
| 467 | } |
| 468 | |
| 469 | /** |
| 470 | * pm_genpd_init - Initialize a generic I/O PM domain object. |
| 471 | * @genpd: PM domain object to initialize. |
| 472 | * @gov: PM domain governor to associate with the domain (may be NULL). |
| 473 | * @is_off: Initial value of the domain's power_is_off field. |
| 474 | */ |
| 475 | void pm_genpd_init(struct generic_pm_domain *genpd, |
| 476 | struct dev_power_governor *gov, bool is_off) |
| 477 | { |
| 478 | if (IS_ERR_OR_NULL(genpd)) |
| 479 | return; |
| 480 | |
| 481 | INIT_LIST_HEAD(&genpd->sd_node); |
| 482 | genpd->parent = NULL; |
| 483 | INIT_LIST_HEAD(&genpd->dev_list); |
| 484 | INIT_LIST_HEAD(&genpd->sd_list); |
| 485 | mutex_init(&genpd->lock); |
| 486 | genpd->gov = gov; |
| 487 | INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); |
| 488 | genpd->in_progress = 0; |
| 489 | genpd->sd_count = 0; |
| 490 | genpd->power_is_off = is_off; |
| 491 | genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; |
| 492 | genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; |
| 493 | genpd->domain.ops.runtime_idle = pm_generic_runtime_idle; |
| 494 | } |