5 files changed, 350 insertions, 6 deletions

diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index f19370641684..ab00eeddecaf 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -335,6 +335,10 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
       'power.runtime_error' is set or 'power.disable_depth' is greater than
       zero)
 
+  bool pm_runtime_suspended(struct device *dev);
+    - return true if the device's runtime PM status is 'suspended', or false
+      otherwise
+
   void pm_runtime_allow(struct device *dev);
     - set the power.runtime_auto flag for the device and decrease its usage
       counter (used by the /sys/devices/.../power/control interface to
@@ -459,3 +463,64 @@ The PM core always increments the run-time usage counter before calling the
 ->prepare() callback and decrements it after calling the ->complete() callback.
 Hence disabling run-time PM temporarily like this will not cause any run-time
 suspend callbacks to be lost.
+
+7. Generic subsystem callbacks
+
+Subsystems may wish to conserve code space by using the set of generic power
+management callbacks provided by the PM core, defined in
+driver/base/power/generic_ops.c:
+
+  int pm_generic_runtime_idle(struct device *dev);
+    - invoke the ->runtime_idle() callback provided by the driver of this
+      device, if defined, and call pm_runtime_suspend() for this device if the
+      return value is 0 or the callback is not defined
+
+  int pm_generic_runtime_suspend(struct device *dev);
+    - invoke the ->runtime_suspend() callback provided by the driver of this
+      device and return its result, or return -EINVAL if not defined
+
+  int pm_generic_runtime_resume(struct device *dev);
+    - invoke the ->runtime_resume() callback provided by the driver of this
+      device and return its result, or return -EINVAL if not defined
+
+  int pm_generic_suspend(struct device *dev);
+    - if the device has not been suspended at run time, invoke the ->suspend()
+      callback provided by its driver and return its result, or return 0 if not
+      defined
+
+  int pm_generic_resume(struct device *dev);
+    - invoke the ->resume() callback provided by the driver of this device and,
+      if successful, change the device's runtime PM status to 'active'
+
+  int pm_generic_freeze(struct device *dev);
+    - if the device has not been suspended at run time, invoke the ->freeze()
+      callback provided by its driver and return its result, or return 0 if not
+      defined
+
+  int pm_generic_thaw(struct device *dev);
+    - if the device has not been suspended at run time, invoke the ->thaw()
+      callback provided by its driver and return its result, or return 0 if not
+      defined
+
+  int pm_generic_poweroff(struct device *dev);
+    - if the device has not been suspended at run time, invoke the ->poweroff()
+      callback provided by its driver and return its result, or return 0 if not
+      defined
+
+  int pm_generic_restore(struct device *dev);
+    - invoke the ->restore() callback provided by the driver of this device and,
+      if successful, change the device's runtime PM status to 'active'
+
+These functions can be assigned to the ->runtime_idle(), ->runtime_suspend(),
+->runtime_resume(), ->suspend(), ->resume(), ->freeze(), ->thaw(), ->poweroff(),
+or ->restore() callback pointers in the subsystem-level dev_pm_ops structures.
+
+If a subsystem wishes to use all of them at the same time, it can simply assign
+the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its
+dev_pm_ops structure pointer.
+
+Device drivers that wish to use the same function as a system suspend, freeze,
+poweroff and run-time suspend callback, and similarly for system resume, thaw,
+restore, and run-time resume, can achieve this with the help of the
+UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its
+last argument to NULL).
diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile
index 3ce3519e8f30..89de75325cea 100644
--- a/drivers/base/power/Makefile
+++ b/drivers/base/power/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_PM)        += sysfs.o
 obj-$(CONFIG_PM_SLEEP)  += main.o
 obj-$(CONFIG_PM_RUNTIME)        += runtime.o
+obj-$(CONFIG_PM_OPS)    += generic_ops.o
 obj-$(CONFIG_PM_TRACE_RTC)      += trace.o
 
 ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
diff --git a/drivers/base/power/generic_ops.c b/drivers/base/power/generic_ops.c
new file mode 100644
index 000000000000..4b29d4981253
--- /dev/null
+++ b/drivers/base/power/generic_ops.c
@@ -0,0 +1,233 @@
+/*
+ * drivers/base/power/generic_ops.c - Generic PM callbacks for subsystems
+ *
+ * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+
+#ifdef CONFIG_PM_RUNTIME
+/**
+ * pm_generic_runtime_idle - Generic runtime idle callback for subsystems.
+ * @dev: Device to handle.
+ *
+ * If PM operations are defined for the @dev's driver and they include
+ * ->runtime_idle(), execute it and return its error code, if nonzero.
+ * Otherwise, execute pm_runtime_suspend() for the device and return 0.
+ */
+int pm_generic_runtime_idle(struct device *dev)
+{
+        const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+        if (pm && pm->runtime_idle) {
+                int ret = pm->runtime_idle(dev);
+                if (ret)
+                        return ret;
+        }
+
+        pm_runtime_suspend(dev);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_runtime_idle);
+
+/**
+ * pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems.
+ * @dev: Device to suspend.
+ *
+ * If PM operations are defined for the @dev's driver and they include
+ * ->runtime_suspend(), execute it and return its error code.  Otherwise,
+ * return -EINVAL.
+ */
+int pm_generic_runtime_suspend(struct device *dev)
+{
+        const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+        int ret;
+
+        ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : -EINVAL;
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(pm_generic_runtime_suspend);
+
+/**
+ * pm_generic_runtime_resume - Generic runtime resume callback for subsystems.
+ * @dev: Device to resume.
+ *
+ * If PM operations are defined for the @dev's driver and they include
+ * ->runtime_resume(), execute it and return its error code.  Otherwise,
+ * return -EINVAL.
+ */
+int pm_generic_runtime_resume(struct device *dev)
+{
+        const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+        int ret;
+
+        ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : -EINVAL;
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(pm_generic_runtime_resume);
+#endif /* CONFIG_PM_RUNTIME */
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * __pm_generic_call - Generic suspend/freeze/poweroff/thaw subsystem callback.
+ * @dev: Device to handle.
+ * @event: PM transition of the system under way.
+ *
+ * If the device has not been suspended at run time, execute the
+ * suspend/freeze/poweroff/thaw callback provided by its driver, if defined, and
+ * return its error code.  Otherwise, return zero.
+ */
+static int __pm_generic_call(struct device *dev, int event)
+{
+        const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+        int (*callback)(struct device *);
+
+        if (!pm || pm_runtime_suspended(dev))
+                return 0;
+
+        switch (event) {