1 files changed, 387 insertions, 15 deletions

diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index 5da914041305..6ecf9ce4a4e6 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -1,25 +1,27 @@
+// 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.
- *
- * This file is released under the GPLv2.
  */
-
-#include <linux/init.h>
 #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 <linux/pm_opp.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 1 if a new object has been created, otherwise
- * return 0 or error code.
+ * 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)
 {
@@ -55,13 +57,11 @@ EXPORT_SYMBOL_GPL(dev_pm_get_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.  Return 1 if that happens or 0
- * otherwise.
+ * reference, power.subsys_data is removed.
  */
-int dev_pm_put_subsys_data(struct device *dev)
+void dev_pm_put_subsys_data(struct device *dev)
 {
 	struct pm_subsys_data *psd;
-	int ret = 1;
 
 	spin_lock_irq(&dev->power.lock);
 
@@ -69,17 +69,389 @@ int dev_pm_put_subsys_data(struct device *dev)
 	if (!psd)
 		goto out;
 
-	if (--psd->refcount == 0) {
+	if (--psd->refcount == 0)
 		dev->power.subsys_data = NULL;
-	} else {
+	else
 		psd = NULL;
-		ret = 0;
-	}
 
  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.
+ * @flags: indicate whether we should power on/off the device on attach/detach
+ *
+ * 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, u32 flags)
+{
+	int ret;
+
+	if (dev->pm_domain)
+		return 0;
+
+	ret = acpi_dev_pm_attach(dev, !!(flags & PD_FLAG_ATTACH_POWER_ON));
+	if (!ret)
+		ret = genpd_dev_pm_attach(dev);
+
+	if (dev->pm_domain)
+		dev->power.detach_power_off = !!(flags & PD_FLAG_DETACH_POWER_OFF);
+
+	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_attach_list - Associate a device with its PM domains.
+ * @dev: The device used to lookup the PM domains for.
+ * @data: The data used for attaching to the PM domains.
+ * @list: An out-parameter with an allocated list of attached PM domains.
+ *
+ * This function helps to attach a device to its multiple PM domains. The
+ * caller, which is typically a driver's probe function, may provide a list of
+ * names for the PM domains that we should try to attach the device to, but it
+ * may also provide an empty list, in case the attach should be done for all of
+ * the available PM domains.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ *
+ * Returns the number of attached PM domains or a negative error code in case of
+ * a failure. Note that, to detach the list of PM domains, the driver shall call
+ * dev_pm_domain_detach_list(), typically during the remove phase.
+ */
+int dev_pm_domain_attach_list(struct device *dev,
+			      const struct dev_pm_domain_attach_data *data,
+			      struct dev_pm_domain_list **list)
+{
+	struct device_node *np = dev->of_node;
+	struct dev_pm_domain_list *pds;
+	struct device *pd_dev = NULL;
+	int ret, i, num_pds = 0;
+	bool by_id = true;
+	size_t size;
+	u32 pd_flags = data ? data->pd_flags : 0;
+	u32 link_flags = pd_flags & PD_FLAG_NO_DEV_LINK ? 0 :
+			DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME;
+
+	if (dev->pm_domain)
+		return -EEXIST;
+
+	/* For now this is limited to OF based platforms. */
+	if (!np)
+		return 0;
+
+	if (data && data->pd_names) {
+		num_pds = data->num_pd_names;
+		by_id = false;
+	} else {
+		num_pds = of_count_phandle_with_args(np, "power-domains",
+						     "#power-domain-cells");
+	}
+
+	if (num_pds <= 0)
+		return 0;
+
+	pds = kzalloc(sizeof(*pds), GFP_KERNEL);
+	if (!pds)
+		return -ENOMEM;
+
+	size = sizeof(*pds->pd_devs) + sizeof(*pds->pd_links) +
+	       sizeof(*pds->opp_tokens);
+	pds->pd_devs = kcalloc(num_pds, size, GFP_KERNEL);
+	if (!pds->pd_devs) {
+		ret = -ENOMEM;
+		goto free_pds;
+	}
+	pds->pd_links = (void *)(pds->pd_devs + num_pds);
+	pds->opp_tokens = (void *)(pds->pd_links + num_pds);
+
+	if (link_flags && pd_flags & PD_FLAG_DEV_LINK_ON)
+		link_flags |= DL_FLAG_RPM_ACTIVE;
+
+	for (i = 0; i < num_pds; i++) {
+		if (by_id)
+			pd_dev = dev_pm_domain_attach_by_id(dev, i);
+		else
+			pd_dev = dev_pm_domain_attach_by_name(dev,
+							data->pd_names[i]);
+		if (IS_ERR_OR_NULL(pd_dev)) {
+			ret = pd_dev ? PTR_ERR(pd_dev) : -ENODEV;
+			goto err_attach;
+		}
+
+		if (pd_flags & PD_FLAG_REQUIRED_OPP) {
+			struct dev_pm_opp_config config = {
+				.required_dev = pd_dev,
+				.required_dev_index = i,
+			};
+
+			ret = dev_pm_opp_set_config(dev, &config);
+			if (ret < 0)
+				goto err_link;
+
+			pds->opp_tokens[i] = ret;
+		}
+
+		if (link_flags) {
+			struct device_link *link;
+
+			link = device_link_add(dev, pd_dev, link_flags);
+			if (!link) {
+				ret = -ENODEV;
+				goto err_link;
+			}
+
+			pds->pd_links[i] = link;
+		}
+
+		pds->pd_devs[i] = pd_dev;
+	}
 
+	pds->num_pds = num_pds;
+	*list = pds;
+	return num_pds;
+
+err_link:
+	dev_pm_opp_clear_config(pds->opp_tokens[i]);
+	dev_pm_domain_detach(pd_dev, true);
+err_attach:
+	while (--i >= 0) {
+		dev_pm_opp_clear_config(pds->opp_tokens[i]);
+		if (pds->pd_links[i])
+			device_link_del(pds->pd_links[i]);
+		dev_pm_domain_detach(pds->pd_devs[i], true);
+	}
+	kfree(pds->pd_devs);
+free_pds:
+	kfree(pds);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
+EXPORT_SYMBOL_GPL(dev_pm_domain_attach_list);
+
+/**
+ * devm_pm_domain_detach_list - devres-enabled version of dev_pm_domain_detach_list.
+ * @_list: The list of PM domains to detach.
+ *
+ * This function reverse the actions from devm_pm_domain_attach_list().
+ * it will be invoked during the remove phase from drivers implicitly if driver
+ * uses devm_pm_domain_attach_list() to attach the PM domains.
+ */
+static void devm_pm_domain_detach_list(void *_list)
+{
+	struct dev_pm_domain_list *list = _list;
+
+	dev_pm_domain_detach_list(list);
+}
+
+/**
+ * devm_pm_domain_attach_list - devres-enabled version of dev_pm_domain_attach_list
+ * @dev: The device used to lookup the PM domains for.
+ * @data: The data used for attaching to the PM domains.
+ * @list: An out-parameter with an allocated list of attached PM domains.
+ *
+ * NOTE: this will also handle calling devm_pm_domain_detach_list() for
+ * you during remove phase.
+ *
+ * Returns the number of attached PM domains or a negative error code in case of
+ * a failure.
+ */
+int devm_pm_domain_attach_list(struct device *dev,
+			       const struct dev_pm_domain_attach_data *data,
+			       struct dev_pm_domain_list **list)
+{
+	int ret, num_pds;
+
+	num_pds = dev_pm_domain_attach_list(dev, data, list);
+	if (num_pds <= 0)
+		return num_pds;
+
+	ret = devm_add_action_or_reset(dev, devm_pm_domain_detach_list, *list);
+	if (ret)
+		return ret;
+
+	return num_pds;
+}
+EXPORT_SYMBOL_GPL(devm_pm_domain_attach_list);
+
+/**
+ * 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_detach_list - Detach a list of PM domains.
+ * @list: The list of PM domains to detach.
+ *
+ * This function reverse the actions from dev_pm_domain_attach_list().
+ * Typically it should be invoked during the remove phase from drivers.
+ *
+ * Callers must ensure proper synchronization of this function with power
+ * management callbacks.
+ */
+void dev_pm_domain_detach_list(struct dev_pm_domain_list *list)
+{
+	int i;
+
+	if (!list)
+		return;
+
+	for (i = 0; i < list->num_pds; i++) {
+		dev_pm_opp_clear_config(list->opp_tokens[i]);
+		if (list->pd_links[i])
+			device_link_del(list->pd_links[i]);
+		dev_pm_domain_detach(list->pd_devs[i], true);
+	}
+
+	kfree(list->pd_devs);
+	kfree(list);
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_detach_list);
+
+/**
+ * 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);
+
+/**
+ * dev_pm_domain_set_performance_state - Request a new performance state.
+ * @dev: The device to make the request for.
+ * @state: Target performance state for the device.
+ *
+ * This function should be called when a new performance state needs to be
+ * requested for a device that is attached to a PM domain. Note that, the
+ * support for performance scaling for PM domains is optional.
+ *
+ * Returns 0 on success and when performance scaling isn't supported, negative
+ * error code on failure.
+ */
+int dev_pm_domain_set_performance_state(struct device *dev, unsigned int state)
+{
+	if (dev->pm_domain && dev->pm_domain->set_performance_state)
+		return dev->pm_domain->set_performance_state(dev, state);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_set_performance_state);