Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / base / power / common.c

diff --git a/kernel/drivers/base/power/common.c b/kernel/drivers/base/power/common.c
new file mode 100644 (file)
index 0000000..f32b802
--- /dev/null
+++ b/kernel/drivers/base/power/common.c
@@ -0,0 +1,130 @@
+/*
+ * drivers/base/power/common.c - Common device power management code.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#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.
+ * @dev: Device to handle.
+ *
+ * If power.subsys_data is NULL, point it to a new object, otherwise increment
+ * its reference counter.  Return 0 if new object has been created or refcount
+ * increased, otherwise negative error code.
+ */
+int dev_pm_get_subsys_data(struct device *dev)
+{
+       struct pm_subsys_data *psd;
+
+       psd = kzalloc(sizeof(*psd), GFP_KERNEL);
+       if (!psd)
+               return -ENOMEM;
+
+       spin_lock_irq(&dev->power.lock);
+
+       if (dev->power.subsys_data) {
+               dev->power.subsys_data->refcount++;
+       } else {
+               spin_lock_init(&psd->lock);
+               psd->refcount = 1;
+               dev->power.subsys_data = psd;
+               pm_clk_init(dev);
+               psd = NULL;
+       }
+
+       spin_unlock_irq(&dev->power.lock);
+
+       /* kfree() verifies that its argument is nonzero. */
+       kfree(psd);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
+
+/**
+ * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
+ * @dev: Device to handle.
+ *
+ * If the reference counter of power.subsys_data is zero after dropping the
+ * reference, power.subsys_data is removed.
+ */
+void dev_pm_put_subsys_data(struct device *dev)
+{
+       struct pm_subsys_data *psd;
+
+       spin_lock_irq(&dev->power.lock);
+
+       psd = dev_to_psd(dev);
+       if (!psd)
+               goto out;
+
+       if (--psd->refcount == 0)
+               dev->power.subsys_data = NULL;
+       else
+               psd = NULL;
+
+ out:
+       spin_unlock_irq(&dev->power.lock);
+       kfree(psd);
+}
+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);