5 files changed, 378 insertions, 6 deletions

diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 356fd86f4ea8..ab00eeddecaf 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -224,6 +224,12 @@ defined in include/linux/pm.h:
       RPM_SUSPENDED, which means that each device is initially regarded by the
       PM core as 'suspended', regardless of its real hardware status
 
+  unsigned int runtime_auto;
+    - if set, indicates that the user space has allowed the device driver to
+      power manage the device at run time via the /sys/devices/.../power/control
+      interface; it may only be modified with the help of the pm_runtime_allow()
+      and pm_runtime_forbid() helper functions
+
 All of the above fields are members of the 'power' member of 'struct device'.
 
 4. Run-time PM Device Helper Functions
@@ -329,6 +335,20 @@ 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
+      effectively allow the device to be power managed at run time)
+
+  void pm_runtime_forbid(struct device *dev);
+    - unset the power.runtime_auto flag for the device and increase its usage
+      counter (used by the /sys/devices/.../power/control interface to
+      effectively prevent the device from being power managed at run time)
+
 It is safe to execute the following helper functions from interrupt context:
 
 pm_request_idle()
@@ -382,6 +402,18 @@ may be desirable to suspend the device as soon as ->probe() or ->remove() has
 finished, so the PM core uses pm_runtime_idle_sync() to invoke the
 subsystem-level idle callback for the device at that time.
 
+The user space can effectively disallow the driver of the device to power manage
+it at run time by changing the value of its /sys/devices/.../power/control
+attribute to "on", which causes pm_runtime_forbid() to be called.  In principle,
+this mechanism may also be used by the driver to effectively turn off the
+run-time power management of the device until the user space turns it on.
+Namely, during the initialization the driver can make sure that the run-time PM
+status of the device is 'active' and call pm_runtime_forbid().  It should be
+noted, however, that if the user space has already intentionally changed the
+value of /sys/devices/.../power/control to "auto" to allow the driver to power
+manage the device at run time, the driver may confuse it by using
+pm_runtime_forbid() this way.
+
 6. Run-time PM and System Sleep
 
 Run-time PM and system sleep (i.e., system suspend and hibernation, also known
@@ -431,3 +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) {
+        case PM_EVENT_SUSPEND:
+                callback = pm->suspend;
+                break;
+        case PM_EVENT_FREEZE:
+                callback = pm->freeze;
+                break;
+        case PM_EVENT_HIBERNATE:
+                callback = pm->poweroff;
+                break;
+        case PM_EVENT_THAW:
+                callback = pm->thaw;
+                break;
+        default:
+                callback = NULL;
+                break;
+        }
+
+        return callback ? callback(dev) : 0;
+}
+
+/**
+ * pm_generic_suspend - Generic suspend callback for subsystems.
+ * @dev: Device to suspend.
+ */
+int pm_generic_suspend(struct device *dev)
+{
+        return __pm_generic_call(dev, PM_EVENT_SUSPEND);
+}
+EXPORT_SYMBOL_GPL(pm_generic_suspend);
+
+/**
+ * pm_generic_freeze - Generic freeze callback for subsystems.
+ * @dev: Device to freeze.
+ */
+int pm_generic_freeze(struct device *dev)
+{
+        return __pm_generic_call(dev, PM_EVENT_FREEZE);
+}
+EXPORT_SYMBOL_GPL(pm_generic_freeze);
+
+/**
+ * pm_generic_poweroff - Generic poweroff callback for subsystems.
+ * @dev: Device to handle.
+ */
+int pm_generic_poweroff(struct device *dev)
+{
+        return __pm_generic_call(dev, PM_EVENT_HIBERNATE);
+}
+EXPORT_SYMBOL_GPL(pm_generic_poweroff);
+
+/**
+ * pm_generic_thaw - Generic thaw callback for subsystems.
+ * @dev: Device to thaw.
+ */
+int pm_generic_thaw(struct device *dev)
+{
+        return __pm_generic_call(dev, PM_EVENT_THAW);
+}
+EXPORT_SYMBOL_GPL(pm_generic_thaw);
+
+/**
+ * __pm_generic_resume - Generic resume/restore callback for subsystems.
+ * @dev: Device to handle.
+ * @event: PM transition of the system under way.
+ *
+ * Execute the resume/resotre callback provided by the @dev's driver, if
+ * defined.  If it returns 0, change the device's runtime PM status to 'active'.
+ * Return the callback's error code.
+ */
+static int __pm_generic_resume(struct device *dev, int event)
+{
+        const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+        int (*callback)(struct device *);
+        int ret;
+
+        if (!pm)
+                return 0;
+
+        switch (event) {
+        case PM_EVENT_RESUME:
+                callback = pm->resume;
+                break;
+        case PM_EVENT_RESTORE:
+                callback = pm->restore;
+                break;
+        default:
+                callback = NULL;
+                break;
+        }
+
+        if (!callback)
+                return 0;
+
+        ret = callback(dev);
+        if (!ret) {
+                pm_runtime_disable(dev);
+                pm_runtime_set_active(dev);
+                pm_runtime_enable(dev);
+        }
+
+        return ret;
+}
+
+/**
+ * pm_generic_resume - Generic resume callback for subsystems.
+ * @dev: Device to resume.
+ */
+int pm_generic_resume(struct device *dev)
+{
+        return __pm_generic_resume(dev, PM_EVENT_RESUME);
+}
+EXPORT_SYMBOL_GPL(pm_generic_resume);
+
+/**
+ * pm_generic_restore - Generic restore callback for subsystems.
+ * @dev: Device to restore.
+ */
+int pm_generic_restore(struct device *dev)
+{
+        return __pm_generic_resume(dev, PM_EVENT_RESTORE);
+}
+EXPORT_SYMBOL_GPL(pm_generic_restore);
+#endif /* CONFIG_PM_SLEEP */
+
+struct dev_pm_ops generic_subsys_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+        .suspend = pm_generic_suspend,
+        .resume = pm_generic_resume,
+        .freeze = pm_generic_freeze,
+        .thaw = pm_generic_thaw,
+        .poweroff = pm_generic_poweroff,
+        .restore = pm_generic_restore,
+#endif
+#ifdef CONFIG_PM_RUNTIME
+        .runtime_suspend = pm_generic_runtime_suspend,
+        .runtime_resume = pm_generic_runtime_resume,
+        .runtime_idle = pm_generic_runtime_idle,
+#endif
+};
+EXPORT_SYMBOL_GPL(generic_subsys_pm_ops);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index e80df06ad22a..8e258c727971 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -215,20 +215,59 @@ struct dev_pm_ops {
         int (*runtime_idle)(struct device *dev);
 };
 
+#ifdef CONFIG_PM_SLEEP
+#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
+        .suspend = suspend_fn, \
+        .resume = resume_fn, \
+        .freeze = suspend_fn, \
+        .thaw = resume_fn, \
+        .poweroff = suspend_fn, \
+        .restore = resume_fn,
+#else
+#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
+#endif
+
+#ifdef CONFIG_PM_RUNTIME
+#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
+        .runtime_suspend = suspend_fn, \
+        .runtime_resume = resume_fn, \
+        .runtime_idle = idle_fn,
+#else
+#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
+#endif
+
 /*
  * Use this if you want to use the same suspend and resume callbacks for suspend
  * to RAM and hibernation.
  */
 #define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
 const struct dev_pm_ops name = { \
-        .suspend = suspend_fn, \
-        .resume = resume_fn, \
-        .freeze = suspend_fn, \
-        .thaw = resume_fn, \
-        .poweroff = suspend_fn, \
-        .restore = resume_fn, \
+        SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
+}
+
+/*
+ * Use this for defining a set of PM operations to be used in all situations
+ * (sustem suspend, hibernation or runtime PM).
+ */
+#define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
+const struct dev_pm_ops name = { \
+        SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
+        SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
 }
 
+/*
+ * Use this for subsystems (bus types, device types, device classes) that don't
+ * need any special suspend/resume handling in addition to invoking the PM
+ * callbacks provided by device drivers supporting both the system sleep PM and
+ * runtime PM, make the pm member point to generic_subsys_pm_ops.
+ */
+#ifdef CONFIG_PM_OPS
+extern struct dev_pm_ops generic_subsys_pm_ops;
+#define GENERIC_SUBSYS_PM_OPS   (&generic_subsys_pm_ops)
+#else
+#define GENERIC_SUBSYS_PM_OPS   NULL
+#endif
+
 /**
  * PM_EVENT_ messages
  *
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 7d773aac5314..b776db737244 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -62,6 +62,11 @@ static inline void device_set_run_wake(struct device *dev, bool enable)
         dev->power.run_wake = enable;
 }
 
+static inline bool pm_runtime_suspended(struct device *dev)
+{
+        return dev->power.runtime_status == RPM_SUSPENDED;
+}
+
 #else /* !CONFIG_PM_RUNTIME */
 
 static inline int pm_runtime_idle(struct device *dev) { return -ENOSYS; }
@@ -89,6 +94,7 @@ static inline void pm_runtime_get_noresume(struct device *dev) {}
 static inline void pm_runtime_put_noidle(struct device *dev) {}
 static inline bool device_run_wake(struct device *dev) { return false; }
 static inline void device_set_run_wake(struct device *dev, bool enable) {}
+static inline bool pm_runtime_suspended(struct device *dev) { return false; }
 
 #endif /* !CONFIG_PM_RUNTIME */