drivers/base/power/generic_ops.c

   1 /*
   2  * drivers/base/power/generic_ops.c - Generic PM callbacks for subsystems
   3  *
   4  * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   5  *
   6  * This file is released under the GPLv2.
   7  */
   8
   9 #include <linux/pm.h>
  10 #include <linux/pm_runtime.h>
  11
  12 #ifdef CONFIG_PM_RUNTIME
  13 /**
  14  * pm_generic_runtime_idle - Generic runtime idle callback for subsystems.
  15  * @dev: Device to handle.
  16  *
  17  * If PM operations are defined for the @dev's driver and they include
  18  * ->runtime_idle(), execute it and return its error code, if nonzero.
  19  * Otherwise, execute pm_runtime_suspend() for the device and return 0.
  20  */
  21 int pm_generic_runtime_idle(struct device *dev)
  22 {
  23         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  24
  25         if (pm && pm->runtime_idle) {
  26                 int ret = pm->runtime_idle(dev);
  27                 if (ret)
  28                         return ret;
  29         }
  30
  31         pm_runtime_suspend(dev);
  32         return 0;
  33 }
  34 EXPORT_SYMBOL_GPL(pm_generic_runtime_idle);
  35
  36 /**
  37  * pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems.
  38  * @dev: Device to suspend.
  39  *
  40  * If PM operations are defined for the @dev's driver and they include
  41  * ->runtime_suspend(), execute it and return its error code.  Otherwise,
  42  * return 0.
  43  */
  44 int pm_generic_runtime_suspend(struct device *dev)
  45 {
  46         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  47         int ret;
  48
  49         ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : 0;
  50
  51         return ret;
  52 }
  53 EXPORT_SYMBOL_GPL(pm_generic_runtime_suspend);
  54
  55 /**
  56  * pm_generic_runtime_resume - Generic runtime resume callback for subsystems.
  57  * @dev: Device to resume.
  58  *
  59  * If PM operations are defined for the @dev's driver and they include
  60  * ->runtime_resume(), execute it and return its error code.  Otherwise,
  61  * return 0.
  62  */
  63 int pm_generic_runtime_resume(struct device *dev)
  64 {
  65         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  66         int ret;
  67
  68         ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : 0;
  69
  70         return ret;
  71 }
  72 EXPORT_SYMBOL_GPL(pm_generic_runtime_resume);
  73 #endif /* CONFIG_PM_RUNTIME */
  74
  75 #ifdef CONFIG_PM_SLEEP
  76 /**
  77  * __pm_generic_call - Generic suspend/freeze/poweroff/thaw subsystem callback.
  78  * @dev: Device to handle.
  79  * @event: PM transition of the system under way.
  80  *
  81  * If the device has not been suspended at run time, execute the
  82  * suspend/freeze/poweroff/thaw callback provided by its driver, if defined, and
  83  * return its error code.  Otherwise, return zero.
  84  */
  85 static int __pm_generic_call(struct device *dev, int event)
  86 {
  87         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
  88         int (*callback)(struct device *);
  89
  90         if (!pm || pm_runtime_suspended(dev))
  91                 return 0;
  92
  93         switch (event) {
  94         case PM_EVENT_SUSPEND:
  95                 callback = pm->suspend;
  96                 break;
  97         case PM_EVENT_FREEZE:
  98                 callback = pm->freeze;
  99                 break;
 100         case PM_EVENT_HIBERNATE:
 101                 callback = pm->poweroff;
 102                 break;
 103         case PM_EVENT_THAW:
 104                 callback = pm->thaw;
 105                 break;
 106         default:
 107                 callback = NULL;
 108                 break;
 109         }
 110
 111         return callback ? callback(dev) : 0;
 112 }
 113
 114 /**
 115  * pm_generic_suspend - Generic suspend callback for subsystems.
 116  * @dev: Device to suspend.
 117  */
 118 int pm_generic_suspend(struct device *dev)
 119 {
 120         return __pm_generic_call(dev, PM_EVENT_SUSPEND);
 121 }
 122 EXPORT_SYMBOL_GPL(pm_generic_suspend);
 123
 124 /**
 125  * pm_generic_freeze - Generic freeze callback for subsystems.
 126  * @dev: Device to freeze.
 127  */
 128 int pm_generic_freeze(struct device *dev)
 129 {
 130         return __pm_generic_call(dev, PM_EVENT_FREEZE);
 131 }
 132 EXPORT_SYMBOL_GPL(pm_generic_freeze);
 133
 134 /**
 135  * pm_generic_poweroff - Generic poweroff callback for subsystems.
 136  * @dev: Device to handle.
 137  */
 138 int pm_generic_poweroff(struct device *dev)
 139 {
 140         return __pm_generic_call(dev, PM_EVENT_HIBERNATE);
 141 }
 142 EXPORT_SYMBOL_GPL(pm_generic_poweroff);
 143
 144 /**
 145  * pm_generic_thaw - Generic thaw callback for subsystems.
 146  * @dev: Device to thaw.
 147  */
 148 int pm_generic_thaw(struct device *dev)
 149 {
 150         return __pm_generic_call(dev, PM_EVENT_THAW);
 151 }
 152 EXPORT_SYMBOL_GPL(pm_generic_thaw);
 153
 154 /**
 155  * __pm_generic_resume - Generic resume/restore callback for subsystems.
 156  * @dev: Device to handle.
 157  * @event: PM transition of the system under way.
 158  *
 159  * Execute the resume/resotre callback provided by the @dev's driver, if
 160  * defined.  If it returns 0, change the device's runtime PM status to 'active'.
 161  * Return the callback's error code.
 162  */
 163 static int __pm_generic_resume(struct device *dev, int event)
 164 {
 165         const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 166         int (*callback)(struct device *);
 167         int ret;
 168
 169         if (!pm)
 170                 return 0;
 171
 172         switch (event) {
 173         case PM_EVENT_RESUME:
 174                 callback = pm->resume;
 175                 break;
 176         case PM_EVENT_RESTORE:
 177                 callback = pm->restore;
 178                 break;
 179         default:
 180                 callback = NULL;
 181                 break;
 182         }
 183
 184         if (!callback)
 185                 return 0;
 186
 187         ret = callback(dev);
 188         if (!ret && pm_runtime_enabled(dev)) {
 189                 pm_runtime_disable(dev);
 190                 pm_runtime_set_active(dev);
 191                 pm_runtime_enable(dev);
 192         }
 193
 194         return ret;
 195 }
 196
 197 /**
 198  * pm_generic_resume - Generic resume callback for subsystems.
 199  * @dev: Device to resume.
 200  */
 201 int pm_generic_resume(struct device *dev)
 202 {
 203         return __pm_generic_resume(dev, PM_EVENT_RESUME);
 204 }
 205 EXPORT_SYMBOL_GPL(pm_generic_resume);
 206
 207 /**
 208  * pm_generic_restore - Generic restore callback for subsystems.
 209  * @dev: Device to restore.
 210  */
 211 int pm_generic_restore(struct device *dev)
 212 {
 213         return __pm_generic_resume(dev, PM_EVENT_RESTORE);
 214 }
 215 EXPORT_SYMBOL_GPL(pm_generic_restore);
 216 #endif /* CONFIG_PM_SLEEP */
 217
 218 struct dev_pm_ops generic_subsys_pm_ops = {
 219 #ifdef CONFIG_PM_SLEEP
 220         .suspend = pm_generic_suspend,
 221         .resume = pm_generic_resume,
 222         .freeze = pm_generic_freeze,
 223         .thaw = pm_generic_thaw,
 224         .poweroff = pm_generic_poweroff,
 225         .restore = pm_generic_restore,
 226 #endif
 227 #ifdef CONFIG_PM_RUNTIME
 228         .runtime_suspend = pm_generic_runtime_suspend,
 229         .runtime_resume = pm_generic_runtime_resume,
 230         .runtime_idle = pm_generic_runtime_idle,
 231 #endif
 232 };
 233 EXPORT_SYMBOL_GPL(generic_subsys_pm_ops);