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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/base/power/common.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/base/power/common.c')
-rw-r--r--drivers/base/power/common.c230
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
new file mode 100644
index 000000000..72115917e
--- /dev/null
+++ b/drivers/base/power/common.c
@@ -0,0 +1,230 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drivers/base/power/common.c - Common device power management code.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ */
+#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>
+
+#include "power.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 when it is found that the
+ * device doesn't need a PM domain, else a negative error code.
+ */
+int dev_pm_domain_attach(struct device *dev, bool power_on)
+{
+ int ret;
+
+ if (dev->pm_domain)
+ return 0;
+
+ ret = acpi_dev_pm_attach(dev, power_on);
+ if (!ret)
+ ret = genpd_dev_pm_attach(dev);
+
+ return ret < 0 ? ret : 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
+
+/**
+ * dev_pm_domain_attach_by_id - Associate a device with one of its PM domains.
+ * @dev: The device used to lookup the PM domain.
+ * @index: The index of the PM domain.
+ *
+ * As @dev may only be attached to a single PM domain, the backend PM domain
+ * provider creates a virtual device to attach instead. If attachment succeeds,
+ * the ->detach() callback in the struct dev_pm_domain are assigned by the
+ * corresponding backend attach function, as to deal with detaching of the
+ * created virtual device.
+ *
+ * This function should typically be invoked by a driver during the probe phase,
+ * in case its device requires power management through multiple PM domains. The
+ * driver may benefit from using the received device, to configure device-links
+ * towards its original device. Depending on the use-case and if needed, the
+ * links may be dynamically changed by the driver, which allows it to control
+ * the power to the PM domains independently from each other.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns the virtual created device when successfully attached to its PM
+ * domain, NULL in case @dev don't need a PM domain, else an ERR_PTR().
+ * Note that, to detach the returned virtual device, the driver shall call
+ * dev_pm_domain_detach() on it, typically during the remove phase.
+ */
+struct device *dev_pm_domain_attach_by_id(struct device *dev,
+ unsigned int index)
+{
+ if (dev->pm_domain)
+ return ERR_PTR(-EEXIST);
+
+ return genpd_dev_pm_attach_by_id(dev, index);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_id);
+
+/**
+ * dev_pm_domain_attach_by_name - Associate a device with one of its PM domains.
+ * @dev: The device used to lookup the PM domain.
+ * @name: The name of the PM domain.
+ *
+ * For a detailed function description, see dev_pm_domain_attach_by_id().
+ */
+struct device *dev_pm_domain_attach_by_name(struct device *dev,
+ const char *name)
+{
+ if (dev->pm_domain)
+ return ERR_PTR(-EEXIST);
+
+ return genpd_dev_pm_attach_by_name(dev, name);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_by_name);
+
+/**
+ * dev_pm_domain_detach - Detach a device from its PM domain.
+ * @dev: Device to detach.
+ * @power_off: Used to indicate whether we should power off the device.
+ *
+ * This functions will reverse the actions from dev_pm_domain_attach(),
+ * dev_pm_domain_attach_by_id() and dev_pm_domain_attach_by_name(), thus it
+ * detaches @dev from its PM domain. Typically it should be invoked during the
+ * remove phase, either from subsystem level code or from drivers.
+ *
+ * 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);
+
+/**
+ * dev_pm_domain_start - Start the device through its PM domain.
+ * @dev: Device to start.
+ *
+ * This function should typically be called during probe by a subsystem/driver,
+ * when it needs to start its device from the PM domain's perspective. Note
+ * that, it's assumed that the PM domain is already powered on when this
+ * function is called.
+ *
+ * Returns 0 on success and negative error values on failures.
+ */
+int dev_pm_domain_start(struct device *dev)
+{
+ if (dev->pm_domain && dev->pm_domain->start)
+ return dev->pm_domain->start(dev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_start);
+
+/**
+ * dev_pm_domain_set - Set PM domain of a device.
+ * @dev: Device whose PM domain is to be set.
+ * @pd: PM domain to be set, or NULL.
+ *
+ * Sets the PM domain the device belongs to. The PM domain of a device needs
+ * to be set before its probe finishes (it's bound to a driver).
+ *
+ * This function must be called with the device lock held.
+ */
+void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
+{
+ if (dev->pm_domain == pd)
+ return;
+
+ WARN(pd && device_is_bound(dev),
+ "PM domains can only be changed for unbound devices\n");
+ dev->pm_domain = pd;
+ device_pm_check_callbacks(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_set);