From: Ulf Hansson <ulf.hansson@linaro.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
linux-pm@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Ulf Hansson <ulf.hansson@linaro.org>,
Kevin Hilman <khilman@linaro.org>,
Alan Stern <stern@rowland.harvard.edu>
Subject: [PATCH 1/5] PM / Sleep: Add pm_generic functions to re-use runtime PM callbacks
Date: Wed, 27 Nov 2013 16:34:56 +0100 [thread overview]
Message-ID: <1385566500-7666-2-git-send-email-ulf.hansson@linaro.org> (raw)
In-Reply-To: <1385566500-7666-1-git-send-email-ulf.hansson@linaro.org>
To put devices into low power state during sleep, it sometimes makes
sense at subsystem-level to re-use the runtime PM callbacks.
The PM core will at device_suspend_late disable runtime PM, after that
we can safely operate on these callbacks. At suspend_late the device
will be put into low power state by invoking the runtime_suspend
callbacks, unless the runtime status is already suspended. At
resume_early the state is restored by invoking the runtime_resume
callbacks. Soon after the PM core will re-enable runtime PM before
returning from device_resume_early.
The new pm_generic functions are named pm_generic_suspend_late_runtime
and pm_generic_resume_early_runtime, they are supposed to be used in
pairs.
Do note that these new generic callbacks will work smothly even with
and without CONFIG_PM_RUNTIME, as long as the runtime PM callbacks are
implemented inside CONFIG_PM instead of CONFIG_PM_RUNTIME.
A special thanks to Alan Stern who came up with this idea.
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/base/power/generic_ops.c | 86 ++++++++++++++++++++++++++++++++++++++
include/linux/pm.h | 2 +
2 files changed, 88 insertions(+)
diff --git a/drivers/base/power/generic_ops.c b/drivers/base/power/generic_ops.c
index 5ee030a..8e78ad1 100644
--- a/drivers/base/power/generic_ops.c
+++ b/drivers/base/power/generic_ops.c
@@ -93,6 +93,49 @@ int pm_generic_suspend_late(struct device *dev)
EXPORT_SYMBOL_GPL(pm_generic_suspend_late);
/**
+ * pm_generic_suspend_late_runtime - Generic suspend_late callback for drivers
+ * @dev: Device to suspend.
+ * Use to invoke runtime_suspend callbacks at suspend_late.
+ */
+int pm_generic_suspend_late_runtime(struct device *dev)
+{
+ int (*callback)(struct device *);
+ int ret = 0;
+
+ /*
+ * PM core has disabled runtime PM in device_suspend_late, thus we can
+ * safely check the device's runtime status and decide whether
+ * additional actions are needed to put the device into low power state.
+ * If so, we invoke the runtime_suspend callbacks.
+ * For the !CONFIG_PM_RUNTIME case, pm_runtime_status_suspended() always
+ * returns false and therefore the runtime_suspend callback will be
+ * invoked.
+ */
+ if (pm_runtime_status_suspended(dev))
+ return 0;
+
+ if (dev->pm_domain)
+ callback = dev->pm_domain->ops.runtime_suspend;
+ else if (dev->type && dev->type->pm)
+ callback = dev->type->pm->runtime_suspend;
+ else if (dev->class && dev->class->pm)
+ callback = dev->class->pm->runtime_suspend;
+ else if (dev->bus && dev->bus->pm)
+ callback = dev->bus->pm->runtime_suspend;
+ else
+ callback = NULL;
+
+ if (!callback && dev->driver && dev->driver->pm)
+ callback = dev->driver->pm->runtime_suspend;
+
+ if (callback)
+ ret = callback(dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pm_generic_suspend_late_runtime);
+
+/**
* pm_generic_suspend - Generic suspend callback for subsystems.
* @dev: Device to suspend.
*/
@@ -237,6 +280,49 @@ int pm_generic_resume_early(struct device *dev)
EXPORT_SYMBOL_GPL(pm_generic_resume_early);
/**
+ * pm_generic_resume_early_runtime - Generic resume_early callback for drivers
+ * @dev: Device to resume.
+ * Use to invoke runtime_resume callbacks at resume_early.
+ */
+int pm_generic_resume_early_runtime(struct device *dev)
+{
+ int (*callback)(struct device *);
+ int ret = 0;
+
+ /*
+ * PM core has not yet enabled runtime PM in device_resume_early,
+ * thus we can safely check the device's runtime status and restore the
+ * previous state we had in device_suspend_late. If restore is needed
+ * we invoke the runtime_resume callbacks.
+ * For the !CONFIG_PM_RUNTIME case, pm_runtime_status_suspended() always
+ * returns false and therefore the runtime_resume callback will be
+ * invoked.
+ */
+ if (pm_runtime_status_suspended(dev))
+ return 0;
+
+ if (dev->pm_domain)
+ callback = dev->pm_domain->ops.runtime_resume;
+ else if (dev->type && dev->type->pm)
+ callback = dev->type->pm->runtime_resume;
+ else if (dev->class && dev->class->pm)
+ callback = dev->class->pm->runtime_resume;
+ else if (dev->bus && dev->bus->pm)
+ callback = dev->bus->pm->runtime_resume;
+ else
+ callback = NULL;
+
+ if (!callback && dev->driver && dev->driver->pm)
+ callback = dev->driver->pm->runtime_resume;
+
+ if (callback)
+ ret = callback(dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pm_generic_resume_early_runtime);
+
+/**
* pm_generic_resume - Generic resume callback for subsystems.
* @dev: Device to resume.
*/
diff --git a/include/linux/pm.h b/include/linux/pm.h
index a224c7f..5bce0d4 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -656,9 +656,11 @@ extern void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *));
extern int pm_generic_prepare(struct device *dev);
extern int pm_generic_suspend_late(struct device *dev);
+extern int pm_generic_suspend_late_runtime(struct device *dev);
extern int pm_generic_suspend_noirq(struct device *dev);
extern int pm_generic_suspend(struct device *dev);
extern int pm_generic_resume_early(struct device *dev);
+extern int pm_generic_resume_early_runtime(struct device *dev);
extern int pm_generic_resume_noirq(struct device *dev);
extern int pm_generic_resume(struct device *dev);
extern int pm_generic_freeze_noirq(struct device *dev);
--
1.7.9.5
next prev parent reply other threads:[~2013-11-27 15:36 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-27 15:34 [PATCH 0/5] PM: Enable option of re-use runtime PM callbacks at system suspend Ulf Hansson
2013-11-27 15:34 ` Ulf Hansson [this message]
2013-12-03 23:15 ` [PATCH 1/5] PM / Sleep: Add pm_generic functions to re-use runtime PM callbacks Rafael J. Wysocki
2013-12-03 23:41 ` Rafael J. Wysocki
2013-12-04 11:00 ` Ulf Hansson
2013-11-27 15:34 ` [PATCH 2/5] PM / Runtime: Implement the pm_generic_runtime functions for CONFIG_PM Ulf Hansson
2013-11-27 15:34 ` [PATCH 3/5] PM / Runtime: Add second macro for definition of runtime PM callbacks Ulf Hansson
2013-11-27 15:34 ` [PATCH 4/5] PM / Sleep: Add macro to define common late/early system " Ulf Hansson
2013-11-27 15:35 ` [PATCH 5/5] drm/exynos: Convert to suspend_late/resume_early callbacks for fimc Ulf Hansson
2013-11-27 20:42 ` [PATCH 0/5] PM: Enable option of re-use runtime PM callbacks at system suspend Rafael J. Wysocki
2013-11-28 9:58 ` Ulf Hansson
2013-11-28 21:16 ` Rafael J. Wysocki
2013-11-29 9:32 ` Ulf Hansson
2013-11-29 9:35 ` Ulf Hansson
2013-11-29 13:52 ` Rafael J. Wysocki
2013-11-29 14:02 ` Rafael J. Wysocki
2013-11-29 15:30 ` Alan Stern
2013-11-29 21:20 ` Rafael J. Wysocki
2013-12-02 15:50 ` Ulf Hansson
2013-12-05 21:46 ` Len Brown
2013-12-05 22:21 ` Alan Stern
2013-12-06 0:53 ` Pavel Machek
2013-12-02 15:21 ` Ulf Hansson
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