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diff --git a/include/power-domain.h b/include/power-domain.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ */
+
+#ifndef _POWER_DOMAIN_H
+#define _POWER_DOMAIN_H
+
+#include <linux/errno.h>
+
+/**
+ * A power domain is a portion of an SoC or chip that is powered by a
+ * switchable source of power. In many cases, software has control over the
+ * power domain, and can turn the power source on or off. This is typically
+ * done to save power by powering off unused devices, or to enable software
+ * sequencing of initial powerup at boot. This API provides a means for
+ * drivers to turn power domains on and off.
+ *
+ * A driver that implements UCLASS_POWER_DOMAIN is a power domain controller or
+ * provider. A controller will often implement multiple separate power domains,
+ * since the hardware it manages often has this capability.
+ * power-domain-uclass.h describes the interface which power domain controllers
+ * must implement.
+ *
+ * Depending on the power domain controller hardware, changing the state of a
+ * power domain may require performing related operations on other resources.
+ * For example, some power domains may require certain clocks to be enabled
+ * whenever the power domain is powered on, or during the time when the power
+ * domain is transitioning state. These details are implementation-specific
+ * and should ideally be encapsulated entirely within the provider driver, or
+ * configured through mechanisms (e.g. device tree) that do not require client
+ * drivers to provide extra configuration information.
+ *
+ * Power domain consumers/clients are the drivers for HW modules within the
+ * power domain. This header file describes the API used by those drivers.
+ *
+ * In many cases, a single complex IO controller (e.g. a PCIe controller) will
+ * be the sole logic contained within a power domain. In such cases, it is
+ * logical for the relevant device driver to directly control that power
+ * domain. In other cases, multiple controllers, each with their own driver,
+ * may be contained in a single power domain. Any logic require to co-ordinate
+ * between drivers for these multiple controllers is beyond the scope of this
+ * API at present. Equally, this API does not define or implement any policy
+ * by which power domains are managed.
+ */
+
+struct udevice;
+
+/**
+ * struct power_domain - A handle to (allowing control of) a single power domain.
+ *
+ * Clients provide storage for power domain handles. The content of the
+ * structure is managed solely by the power domain API and power domain
+ * drivers. A power domain struct is initialized by "get"ing the power domain
+ * struct. The power domain struct is passed to all other power domain APIs to
+ * identify which power domain to operate upon.
+ *
+ * @dev: The device which implements the power domain.
+ * @id: The power domain ID within the provider.
+ * @priv: Private data corresponding to each power domain.
+ */
+struct power_domain {
+	struct udevice *dev;
+	unsigned long id;
+	void *priv;
+};
+
+/**
+ * struct power_domain_plat - Per device accessible structure
+ * @subdomains: Number of subdomains covered by this device, required
+ *              for refcounting
+ */
+struct power_domain_plat {
+	int subdomains;
+};
+
+/**
+ * power_domain_get - Get/request the power domain for a device.
+ *
+ * This looks up and requests a power domain. Each device is assumed to have
+ * a single (or, at least one) power domain associated with it somehow, and
+ * that domain, or the first/default domain. The mapping of client device to
+ * provider power domain may be via device-tree properties, board-provided
+ * mapping tables, or some other mechanism.
+ *
+ * @dev:	The client device.
+ * @power_domain	A pointer to a power domain struct to initialize.
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_get(struct udevice *dev, struct power_domain *power_domain);
+#else
+static inline
+int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_get_by_index - Get the indexed power domain for a device.
+ *
+ * @dev:		The client device.
+ * @power_domain:	A pointer to a power domain struct to initialize.
+ * @index:		Power domain index to be powered on.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_get_by_index(struct udevice *dev,
+			      struct power_domain *power_domain, int index);
+#else
+static inline
+int power_domain_get_by_index(struct udevice *dev,
+			      struct power_domain *power_domain, int index)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_get_by_name - Get the named power domain for a device.
+ *
+ * @dev:		The client device.
+ * @power_domain:	A pointer to a power domain struct to initialize.
+ * @name:		Power domain name to be powered on.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_get_by_name(struct udevice *dev,
+			     struct power_domain *power_domain, const char *name);
+#else
+static inline
+int power_domain_get_by_name(struct udevice *dev,
+			     struct power_domain *power_domain, const char *name)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_free - Free a previously requested power domain.
+ *
+ * @power_domain:	A power domain struct that was previously successfully
+ *		requested by power_domain_get().
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_free(struct power_domain *power_domain);
+#else
+static inline int power_domain_free(struct power_domain *power_domain)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_on_lowlevel - Enable power to a power domain (with refcounting)
+ *
+ * @power_domain:	A power domain struct that was previously successfully
+ *		requested by power_domain_get().
+ * Return: 0 if the transition has been performed correctly,
+ *         -EALREADY if the domain is already on,
+ *         a negative error code otherwise.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_on_lowlevel(struct power_domain *power_domain);
+#else
+static inline int power_domain_on_lowlevel(struct power_domain *power_domain)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_on - Enable power to a power domain (ignores the actual state
+ *		      of the power domain)
+ *
+ * @power_domain:	A power domain struct that was previously successfully
+ *		requested by power_domain_get().
+ * Return: a negative error code upon error during the transition, 0 otherwise.
+ */
+static inline int power_domain_on(struct power_domain *power_domain)
+{
+	int ret;
+
+	ret = power_domain_on_lowlevel(power_domain);
+	if (ret == -EALREADY)
+		ret = 0;
+
+	return ret;
+}
+
+/**
+ * power_domain_off_lowlevel - Disable power to a power domain (with refcounting)
+ *
+ * @power_domain:	A power domain struct that was previously successfully
+ *		requested by power_domain_get().
+ * Return: 0 if the transition has been performed correctly,
+ *         -EALREADY if the domain is already off,
+ *         -EBUSY if another device is keeping the domain on (but the refcounter
+ *         is decremented),
+ *         a negative error code otherwise.
+ */
+#if CONFIG_IS_ENABLED(POWER_DOMAIN)
+int power_domain_off_lowlevel(struct power_domain *power_domain);
+#else
+static inline int power_domain_off_lowlevel(struct power_domain *power_domain)
+{
+	return -ENOSYS;
+}
+#endif
+
+/**
+ * power_domain_off - Disable power to a power domain (ignores the actual state
+ *		      of the power domain)
+ *
+ * @power_domain:	A power domain struct that was previously successfully
+ *		requested by power_domain_get().
+ * Return: a negative error code upon error during the transition, 0 otherwise.
+ */
+static inline int power_domain_off(struct power_domain *power_domain)
+{
+	int ret;
+
+	ret = power_domain_off_lowlevel(power_domain);
+	if (ret == -EALREADY || ret == -EBUSY)
+		ret = 0;
+
+	return ret;
+}
+
+/**
+ * dev_power_domain_on - Enable power domains for a device .
+ *
+ * @dev:		The client device.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(OF_REAL) && CONFIG_IS_ENABLED(POWER_DOMAIN)
+int dev_power_domain_on(struct udevice *dev);
+#else
+static inline int dev_power_domain_on(struct udevice *dev)
+{
+	return 0;
+}
+#endif
+
+/**
+ * dev_power_domain_off - Disable power domains for a device .
+ *
+ * @dev:		The client device.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+#if CONFIG_IS_ENABLED(OF_REAL) && CONFIG_IS_ENABLED(POWER_DOMAIN)
+int dev_power_domain_off(struct udevice *dev);
+#else
+static inline int dev_power_domain_off(struct udevice *dev)
+{
+	return 0;
+}
+#endif
+
+#endif