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authorUlf Hansson <ulf.hansson@linaro.org>2014-09-19 18:27:37 (GMT)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-22 13:57:40 (GMT)
commit46420dd73b800f87a19af13af5883855cf38cb08 (patch)
treebe10bd4b1d36b76fb776cc000a71c1f09ea96a42 /drivers/base
parentaa42240ab2544a8bcb2efb400193826f57f3175e (diff)
downloadlinux-46420dd73b800f87a19af13af5883855cf38cb08.tar.xz
PM / Domains: Add APIs to attach/detach a PM domain for a device
To maintain scalability let's add common methods to attach and detach a PM domain for a device, dev_pm_domain_attach|detach(). Typically dev_pm_domain_attach() shall be invoked from subsystem level code at the probe phase to try to attach a device to its PM domain. The reversed actions may be done a the remove phase and then by invoking dev_pm_domain_detach(). When attachment succeeds, the attach function should assign its corresponding detach function to a new ->detach() callback added in the struct dev_pm_domain. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Kevin Hilman <khilman@linaro.org> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/common.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index df2e5ee..b0f1388 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -11,6 +11,8 @@
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/pm_clock.h>
+#include <linux/acpi.h>
+#include <linux/pm_domain.h>
/**
* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
@@ -82,3 +84,53 @@ int dev_pm_put_subsys_data(struct device *dev)
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
+
+/**
+ * dev_pm_domain_attach - Attach a device to its PM domain.
+ * @dev: Device to attach.
+ * @power_on: Used to indicate whether we should power on the device.
+ *
+ * The @dev may only be attached to a single PM domain. By iterating through
+ * the available alternatives we try to find a valid PM domain for the device.
+ * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
+ * should be assigned by the corresponding attach function.
+ *
+ * This function should typically be invoked from subsystem level code during
+ * the probe phase. Especially for those that holds devices which requires
+ * power management through PM domains.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns 0 on successfully attached PM domain or negative error code.
+ */
+int dev_pm_domain_attach(struct device *dev, bool power_on)
+{
+ int ret;
+
+ ret = acpi_dev_pm_attach(dev, power_on);
+ if (ret)
+ ret = genpd_dev_pm_attach(dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
+
+/**
+ * dev_pm_domain_detach - Detach a device from its PM domain.
+ * @dev: Device to attach.
+ * @power_off: Used to indicate whether we should power off the device.
+ *
+ * This functions will reverse the actions from dev_pm_domain_attach() and thus
+ * try to detach the @dev from its PM domain. Typically it should be invoked
+ * from subsystem level code during the remove phase.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ */
+void dev_pm_domain_detach(struct device *dev, bool power_off)
+{
+ if (dev->pm_domain && dev->pm_domain->detach)
+ dev->pm_domain->detach(dev, power_off);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_detach);