Merge branch 'pm-domains'

* pm-domains:
  PM / Domains: Rename pm_genpd_sync_poweron|poweroff()
  PM / Domains: Don't measure latency of ->power_on|off() during system PM
  PM / Domains: Remove redundant system PM callbacks
  PM / Domains: Simplify detaching a device from its genpd
  PM / Domains: Allow holes in genpd_data.domains array
  PM / Domains: Add support for removing nested PM domains by provider
  PM / Domains: Add support for removing PM domains
  PM / Domains: Store the provider in the PM domain structure
  PM / Domains: Prepare for adding support to remove PM domains
  PM / Domains: Verify the PM domain is present when adding a provider
  PM / Domains: Don't expose xlate and provider helper functions
  PM / Domains: Don't expose generic_pm_domain structure to clients
  staging: board: Remove calls to of_genpd_get_from_provider()
  ARM: EXYNOS: Remove calls to of_genpd_get_from_provider()
  PM / Domains: Add new helper functions for device-tree
  PM / Domains: Always enable debugfs support if available

drivers/base/power/domain.c

@@ -45,7 +45,7 @@ static DEFINE_MUTEX(gpd_list_lock);
  * and checks that the PM domain pointer is a real generic PM domain.
  * Any failure results in NULL being returned.
  */
-struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev)
+static struct generic_pm_domain *genpd_lookup_dev(struct device *dev)
 {
 	struct generic_pm_domain *genpd = NULL, *gpd;
 
@@ -586,7 +586,7 @@ static int __init genpd_poweroff_unused(void)
 }
 late_initcall(genpd_poweroff_unused);
 
-#ifdef CONFIG_PM_SLEEP
+#if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM_GENERIC_DOMAINS_OF)
 
 /**
  * pm_genpd_present - Check if the given PM domain has been initialized.
@@ -606,6 +606,10 @@ static bool pm_genpd_present(const struct generic_pm_domain *genpd)
 	return false;
 }
 
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+
 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 				    struct device *dev)
 {
@@ -613,9 +617,8 @@ static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 }
 
 /**
- * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
+ * genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
  * @genpd: PM domain to power off, if possible.
- * @timed: True if latency measurements are allowed.
  *
  * Check if the given PM domain can be powered off (during system suspend or
  * hibernation) and do that if so.  Also, in that case propagate to its masters.
@@ -625,8 +628,7 @@ static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
  * executed sequentially, so it is guaranteed that it will never run twice in
  * parallel).
  */
-static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd,
-				   bool timed)
+static void genpd_sync_poweroff(struct generic_pm_domain *genpd)
 {
 	struct gpd_link *link;
 
@@ -639,28 +641,26 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd,
 
 	/* Choose the deepest state when suspending */
 	genpd->state_idx = genpd->state_count - 1;
-	genpd_power_off(genpd, timed);
+	genpd_power_off(genpd, false);
 
 	genpd->status = GPD_STATE_POWER_OFF;
 
 	list_for_each_entry(link, &genpd->slave_links, slave_node) {
 		genpd_sd_counter_dec(link->master);
-		pm_genpd_sync_poweroff(link->master, timed);
+		genpd_sync_poweroff(link->master);
 	}
 }
 
 /**
- * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
+ * genpd_sync_poweron - Synchronously power on a PM domain and its masters.
  * @genpd: PM domain to power on.
- * @timed: True if latency measurements are allowed.
  *
  * This function is only called in "noirq" and "syscore" stages of system power
  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
  * executed sequentially, so it is guaranteed that it will never run twice in
  * parallel).
  */
-static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd,
-				  bool timed)
+static void genpd_sync_poweron(struct generic_pm_domain *genpd)
 {
 	struct gpd_link *link;
 
@@ -668,11 +668,11 @@ static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd,
 		return;
 
 	list_for_each_entry(link, &genpd->slave_links, slave_node) {
-		pm_genpd_sync_poweron(link->master, timed);
+		genpd_sync_poweron(link->master);
 		genpd_sd_counter_inc(link->master);
 	}
 
-	genpd_power_on(genpd, timed);
+	genpd_power_on(genpd, false);
 
 	genpd->status = GPD_STATE_ACTIVE;
 }
@@ -784,7 +784,7 @@ static int pm_genpd_suspend_noirq(struct device *dev)
 	 * the same PM domain, so it is not necessary to use locking here.
 	 */
 	genpd->suspended_count++;
-	pm_genpd_sync_poweroff(genpd, true);
+	genpd_sync_poweroff(genpd);
 
 	return 0;
 }
@@ -814,7 +814,7 @@ static int pm_genpd_resume_noirq(struct device *dev)
 	 * guaranteed that this function will never run twice in parallel for
 	 * the same PM domain, so it is not necessary to use locking here.
 	 */
-	pm_genpd_sync_poweron(genpd, true);
+	genpd_sync_poweron(genpd);
 	genpd->suspended_count--;
 
 	if (genpd->dev_ops.stop && genpd->dev_ops.start)
@@ -902,12 +902,12 @@ static int pm_genpd_restore_noirq(struct device *dev)
 	if (genpd->suspended_count++ == 0)
 		/*
 		 * The boot kernel might put the domain into arbitrary state,
-		 * so make it appear as powered off to pm_genpd_sync_poweron(),
+		 * so make it appear as powered off to genpd_sync_poweron(),
 		 * so that it tries to power it on in case it was really off.
 		 */
 		genpd->status = GPD_STATE_POWER_OFF;
 
-	pm_genpd_sync_poweron(genpd, true);
+	genpd_sync_poweron(genpd);
 
 	if (genpd->dev_ops.stop && genpd->dev_ops.start)
 		ret = pm_runtime_force_resume(dev);
@@ -962,9 +962,9 @@ static void genpd_syscore_switch(struct device *dev, bool suspend)
 
 	if (suspend) {
 		genpd->suspended_count++;
-		pm_genpd_sync_poweroff(genpd, false);
+		genpd_sync_poweroff(genpd);
 	} else {
-		pm_genpd_sync_poweron(genpd, false);
+		genpd_sync_poweron(genpd);
 		genpd->suspended_count--;
 	}
 }
@@ -1056,13 +1056,7 @@ static void genpd_free_dev_data(struct device *dev,
 	dev_pm_put_subsys_data(dev);
 }
 
-/**
- * __pm_genpd_add_device - Add a device to an I/O PM domain.
- * @genpd: PM domain to add the device to.
- * @dev: Device to be added.
- * @td: Set of PM QoS timing parameters to attach to the device.
- */
-int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
+static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 			    struct gpd_timing_data *td)
 {
 	struct generic_pm_domain_data *gpd_data;
@@ -1103,14 +1097,27 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(__pm_genpd_add_device);
 
 /**
- * pm_genpd_remove_device - Remove a device from an I/O PM domain.
- * @genpd: PM domain to remove the device from.
- * @dev: Device to be removed.
+ * __pm_genpd_add_device - Add a device to an I/O PM domain.
+ * @genpd: PM domain to add the device to.
+ * @dev: Device to be added.
+ * @td: Set of PM QoS timing parameters to attach to the device.
  */
-int pm_genpd_remove_device(struct generic_pm_domain *genpd,
+int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
+			  struct gpd_timing_data *td)
+{
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+	ret = genpd_add_device(genpd, dev, td);
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__pm_genpd_add_device);
+
+static int genpd_remove_device(struct generic_pm_domain *genpd,
 			       struct device *dev)
 {
 	struct generic_pm_domain_data *gpd_data;
@@ -1119,10 +1126,6 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 
 	dev_dbg(dev, "%s()\n", __func__);
 
-	if (!genpd || genpd != pm_genpd_lookup_dev(dev))
-		return -EINVAL;
-
-	/* The above validation also means we have existing domain_data. */
 	pdd = dev->power.subsys_data->domain_data;
 	gpd_data = to_gpd_data(pdd);
 	dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
@@ -1154,14 +1157,23 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
 
 /**
- * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
- * @genpd: Master PM domain to add the subdomain to.
- * @subdomain: Subdomain to be added.
+ * pm_genpd_remove_device - Remove a device from an I/O PM domain.
+ * @genpd: PM domain to remove the device from.
+ * @dev: Device to be removed.
  */
-int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+int pm_genpd_remove_device(struct generic_pm_domain *genpd,
+			   struct device *dev)
+{
+	if (!genpd || genpd != genpd_lookup_dev(dev))
+		return -EINVAL;
+
+	return genpd_remove_device(genpd, dev);
+}
+EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
+
+static int genpd_add_subdomain(struct generic_pm_domain *genpd,
 			       struct generic_pm_domain *subdomain)
 {
 	struct gpd_link *link, *itr;
@@ -1205,6 +1217,23 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 		kfree(link);
 	return ret;
 }
+
+/**
+ * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
+ * @genpd: Master PM domain to add the subdomain to.
+ * @subdomain: Subdomain to be added.
+ */
+int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+			   struct generic_pm_domain *subdomain)
+{
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+	ret = genpd_add_subdomain(genpd, subdomain);
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
 EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
 
 /**
@@ -1278,27 +1307,17 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 	genpd->device_count = 0;
 	genpd->max_off_time_ns = -1;
 	genpd->max_off_time_changed = true;
+	genpd->provider = NULL;
+	genpd->has_provider = false;
 	genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
 	genpd->domain.ops.runtime_resume = genpd_runtime_resume;
 	genpd->domain.ops.prepare = pm_genpd_prepare;
-	genpd->domain.ops.suspend = pm_generic_suspend;
-	genpd->domain.ops.suspend_late = pm_generic_suspend_late;
 	genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
 	genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
-	genpd->domain.ops.resume_early = pm_generic_resume_early;
-	genpd->domain.ops.resume = pm_generic_resume;
-	genpd->domain.ops.freeze = pm_generic_freeze;
-	genpd->domain.ops.freeze_late = pm_generic_freeze_late;
 	genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
 	genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
-	genpd->domain.ops.thaw_early = pm_generic_thaw_early;
-	genpd->domain.ops.thaw = pm_generic_thaw;
-	genpd->domain.ops.poweroff = pm_generic_poweroff;
-	genpd->domain.ops.poweroff_late = pm_generic_poweroff_late;
 	genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
 	genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
-	genpd->domain.ops.restore_early = pm_generic_restore_early;
-	genpd->domain.ops.restore = pm_generic_restore;
 	genpd->domain.ops.complete = pm_genpd_complete;
 
 	if (genpd->flags & GENPD_FLAG_PM_CLK) {
@@ -1328,7 +1347,71 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 }
 EXPORT_SYMBOL_GPL(pm_genpd_init);
 
+static int genpd_remove(struct generic_pm_domain *genpd)
+{
+	struct gpd_link *l, *link;
+
+	if (IS_ERR_OR_NULL(genpd))
+		return -EINVAL;
+
+	mutex_lock(&genpd->lock);
+
+	if (genpd->has_provider) {
+		mutex_unlock(&genpd->lock);
+		pr_err("Provider present, unable to remove %s\n", genpd->name);
+		return -EBUSY;
+	}
+
+	if (!list_empty(&genpd->master_links) || genpd->device_count) {
+		mutex_unlock(&genpd->lock);
+		pr_err("%s: unable to remove %s\n", __func__, genpd->name);
+		return -EBUSY;
+	}
+
+	list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) {
+		list_del(&link->master_node);
+		list_del(&link->slave_node);
+		kfree(link);
+	}
+
+	list_del(&genpd->gpd_list_node);
+	mutex_unlock(&genpd->lock);
+	cancel_work_sync(&genpd->power_off_work);
+	pr_debug("%s: removed %s\n", __func__, genpd->name);
+
+	return 0;
+}
+
+/**
+ * pm_genpd_remove - Remove a generic I/O PM domain
+ * @genpd: Pointer to PM domain that is to be removed.
+ *
+ * To remove the PM domain, this function:
+ *  - Removes the PM domain as a subdomain to any parent domains,
+ *    if it was added.
+ *  - Removes the PM domain from the list of registered PM domains.
+ *
+ * The PM domain will only be removed, if the associated provider has
+ * been removed, it is not a parent to any other PM domain and has no
+ * devices associated with it.
+ */
+int pm_genpd_remove(struct generic_pm_domain *genpd)
+{
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+	ret = genpd_remove(genpd);
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pm_genpd_remove);
+
 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
+
+typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args,
+						   void *data);
+
 /*
  * Device Tree based PM domain providers.
  *
@@ -1340,8 +1423,8 @@ EXPORT_SYMBOL_GPL(pm_genpd_init);
  * maps a PM domain specifier retrieved from the device tree to a PM domain.
  *
  * Two simple mapping functions have been provided for convenience:
- *  - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
- *  - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by
+ *  - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
+ *  - genpd_xlate_onecell() for mapping of multiple PM domains per node by
  *    index.
  */
 
@@ -1366,7 +1449,7 @@ static LIST_HEAD(of_genpd_providers);
 static DEFINE_MUTEX(of_genpd_mutex);
 
 /**
- * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping
+ * genpd_xlate_simple() - Xlate function for direct node-domain mapping
  * @genpdspec: OF phandle args to map into a PM domain
  * @data: xlate function private data - pointer to struct generic_pm_domain
  *
@@ -1374,7 +1457,7 @@ static DEFINE_MUTEX(of_genpd_mutex);
  * have their own device tree nodes. The private data of xlate function needs
  * to be a valid pointer to struct generic_pm_domain.
  */
-struct generic_pm_domain *__of_genpd_xlate_simple(
+static struct generic_pm_domain *genpd_xlate_simple(
 					struct of_phandle_args *genpdspec,
 					void *data)
 {
@@ -1382,10 +1465,9 @@ struct generic_pm_domain *__of_genpd_xlate_simple(
 		return ERR_PTR(-EINVAL);
 	return data;
 }
-EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
 
 /**
- * __of_genpd_xlate_onecell() - Xlate function using a single index.
+ * genpd_xlate_onecell() - Xlate function using a single index.
  * @genpdspec: OF phandle args to map into a PM domain
  * @data: xlate function private data - pointer to struct genpd_onecell_data
  *
@@ -1394,7 +1476,7 @@ EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
  * A single cell is used as an index into an array of PM domains specified in
  * the genpd_onecell_data struct when registering the provider.
  */
-struct generic_pm_domain *__of_genpd_xlate_onecell(
+static struct generic_pm_domain *genpd_xlate_onecell(
 					struct of_phandle_args *genpdspec,
 					void *data)
 {
@@ -1414,15 +1496,14 @@ struct generic_pm_domain *__of_genpd_xlate_onecell(
 
 	return genpd_data->domains[idx];
 }
-EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell);
 
 /**
- * __of_genpd_add_provider() - Register a PM domain provider for a node
+ * genpd_add_provider() - Register a PM domain provider for a node
  * @np: Device node pointer associated with the PM domain provider.
  * @xlate: Callback for decoding PM domain from phandle arguments.
  * @data: Context pointer for @xlate callback.
  */
-int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
+static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
 			      void *data)
 {
 	struct of_genpd_provider *cp;
@@ -1442,7 +1523,83 @@ int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
+
+/**
+ * of_genpd_add_provider_simple() - Register a simple PM domain provider
+ * @np: Device node pointer associated with the PM domain provider.
+ * @genpd: Pointer to PM domain associated with the PM domain provider.
+ */
+int of_genpd_add_provider_simple(struct device_node *np,
+				 struct generic_pm_domain *genpd)
+{
+	int ret = -EINVAL;
+
+	if (!np || !genpd)
+		return -EINVAL;
+
+	mutex_lock(&gpd_list_lock);
+
+	if (pm_genpd_present(genpd))
+		ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
+
+	if (!ret) {
+		genpd->provider = &np->fwnode;
+		genpd->has_provider = true;
+	}
+
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple);
+
+/**
+ * of_genpd_add_provider_onecell() - Register a onecell PM domain provider
+ * @np: Device node pointer associated with the PM domain provider.
+ * @data: Pointer to the data associated with the PM domain provider.
+ */
+int of_genpd_add_provider_onecell(struct device_node *np,
+				  struct genpd_onecell_data *data)
+{
+	unsigned int i;
+	int ret = -EINVAL;
+
+	if (!np || !data)
+		return -EINVAL;
+
+	mutex_lock(&gpd_list_lock);
+
+	for (i = 0; i < data->num_domains; i++) {
+		if (!data->domains[i])
+			continue;
+		if (!pm_genpd_present(data->domains[i]))
+			goto error;
+
+		data->domains[i]->provider = &np->fwnode;
+		data->domains[i]->has_provider = true;
+	}
+
+	ret = genpd_add_provider(np, genpd_xlate_onecell, data);
+	if (ret < 0)
+		goto error;
+
+	mutex_unlock(&gpd_list_lock);
+
+	return 0;
+
+error:
+	while (i--) {
+		if (!data->domains[i])
+			continue;
+		data->domains[i]->provider = NULL;
+		data->domains[i]->has_provider = false;
+	}
+
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
 
 /**
  * of_genpd_del_provider() - Remove a previously registered PM domain provider
@@ -1451,10 +1608,21 @@ EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
 void of_genpd_del_provider(struct device_node *np)
 {
 	struct of_genpd_provider *cp;
+	struct generic_pm_domain *gpd;
 
+	mutex_lock(&gpd_list_lock);
 	mutex_lock(&of_genpd_mutex);
 	list_for_each_entry(cp, &of_genpd_providers, link) {
 		if (cp->node == np) {
+			/*
+			 * For each PM domain associated with the
+			 * provider, set the 'has_provider' to false
+			 * so that the PM domain can be safely removed.
+			 */
+			list_for_each_entry(gpd, &gpd_list, gpd_list_node)
+				if (gpd->provider == &np->fwnode)
+					gpd->has_provider = false;
+
 			list_del(&cp->link);
 			of_node_put(cp->node);
 			kfree(cp);
@@ -1462,11 +1630,12 @@ void of_genpd_del_provider(struct device_node *np)
 		}
 	}
 	mutex_unlock(&of_genpd_mutex);
+	mutex_unlock(&gpd_list_lock);
 }
 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
 
 /**
- * of_genpd_get_from_provider() - Look-up PM domain
+ * genpd_get_from_provider() - Look-up PM domain
  * @genpdspec: OF phandle args to use for look-up
  *
  * Looks for a PM domain provider under the node specified by @genpdspec and if
@@ -1476,7 +1645,7 @@ EXPORT_SYMBOL_GPL(of_genpd_del_provider);
  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
  * on failure.
  */
-struct generic_pm_domain *of_genpd_get_from_provider(
+static struct generic_pm_domain *genpd_get_from_provider(
 					struct of_phandle_args *genpdspec)
 {
 	struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
@@ -1499,7 +1668,109 @@ struct generic_pm_domain *of_genpd_get_from_provider(
 
 	return genpd;
 }
-EXPORT_SYMBOL_GPL(of_genpd_get_from_provider);
+
+/**
+ * of_genpd_add_device() - Add a device to an I/O PM domain
+ * @genpdspec: OF phandle args to use for look-up PM domain
+ * @dev: Device to be added.
+ *
+ * Looks-up an I/O PM domain based upon phandle args provided and adds
+ * the device to the PM domain. Returns a negative error code on failure.
+ */
+int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
+{
+	struct generic_pm_domain *genpd;
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+
+	genpd = genpd_get_from_provider(genpdspec);
+	if (IS_ERR(genpd)) {
+		ret = PTR_ERR(genpd);
+		goto out;
+	}
+
+	ret = genpd_add_device(genpd, dev, NULL);
+
+out:
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_genpd_add_device);
+
+/**
+ * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
+ * @parent_spec: OF phandle args to use for parent PM domain look-up
+ * @subdomain_spec: OF phandle args to use for subdomain look-up
+ *
+ * Looks-up a parent PM domain and subdomain based upon phandle args
+ * provided and adds the subdomain to the parent PM domain. Returns a
+ * negative error code on failure.
+ */
+int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
+			   struct of_phandle_args *subdomain_spec)
+{
+	struct generic_pm_domain *parent, *subdomain;
+	int ret;
+
+	mutex_lock(&gpd_list_lock);
+
+	parent = genpd_get_from_provider(parent_spec);
+	if (IS_ERR(parent)) {
+		ret = PTR_ERR(parent);
+		goto out;
+	}
+
+	subdomain = genpd_get_from_provider(subdomain_spec);
+	if (IS_ERR(subdomain)) {
+		ret = PTR_ERR(subdomain);
+		goto out;
+	}
+
+	ret = genpd_add_subdomain(parent, subdomain);
+
+out:
+	mutex_unlock(&gpd_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
+
+/**
+ * of_genpd_remove_last - Remove the last PM domain registered for a provider
+ * @provider: Pointer to device structure associated with provider
+ *
+ * Find the last PM domain that was added by a particular provider and
+ * remove this PM domain from the list of PM domains. The provider is
+ * identified by the 'provider' device structure that is passed. The PM
+ * domain will only be removed, if the provider associated with domain
+ * has been removed.
+ *
+ * Returns a valid pointer to struct generic_pm_domain on success or
+ * ERR_PTR() on failure.
+ */
+struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
+{
+	struct generic_pm_domain *gpd, *genpd = ERR_PTR(-ENOENT);
+	int ret;
+
+	if (IS_ERR_OR_NULL(np))
+		return ERR_PTR(-EINVAL);
+
+	mutex_lock(&gpd_list_lock);
+	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
+		if (gpd->provider == &np->fwnode) {
+			ret = genpd_remove(gpd);
+			genpd = ret ? ERR_PTR(ret) : gpd;
+			break;
+		}
+	}
+	mutex_unlock(&gpd_list_lock);
+
+	return genpd;
+}
+EXPORT_SYMBOL_GPL(of_genpd_remove_last);
 
 /**
  * genpd_dev_pm_detach - Detach a device from its PM domain.
@@ -1515,14 +1786,14 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
 	unsigned int i;
 	int ret = 0;
 
-	pd = pm_genpd_lookup_dev(dev);
-	if (!pd)
+	pd = dev_to_genpd(dev);
+	if (IS_ERR(pd))
 		return;
 
 	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
 
 	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
-		ret = pm_genpd_remove_device(pd, dev);
+		ret = genpd_remove_device(pd, dev);
 		if (ret != -EAGAIN)
 			break;
 
@@ -1596,9 +1867,11 @@ int genpd_dev_pm_attach(struct device *dev)
 			return -ENOENT;
 	}
 
-	pd = of_genpd_get_from_provider(&pd_args);
+	mutex_lock(&gpd_list_lock);
+	pd = genpd_get_from_provider(&pd_args);
 	of_node_put(pd_args.np);
 	if (IS_ERR(pd)) {
+		mutex_unlock(&gpd_list_lock);
 		dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
 			__func__, PTR_ERR(pd));
 		return -EPROBE_DEFER;
@@ -1607,13 +1880,14 @@ int genpd_dev_pm_attach(struct device *dev)
 	dev_dbg(dev, "adding to PM domain %s\n", pd->name);
 
 	for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
-		ret = pm_genpd_add_device(pd, dev);
+		ret = genpd_add_device(pd, dev, NULL);
 		if (ret != -EAGAIN)
 			break;
 
 		mdelay(i);
 		cond_resched();
 	}
+	mutex_unlock(&gpd_list_lock);
 
 	if (ret < 0) {
 		dev_err(dev, "failed to add to PM domain %s: %d",
@@ -1636,7 +1910,7 @@ EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
 
 /***        debugfs support        ***/
 
-#ifdef CONFIG_PM_ADVANCED_DEBUG
+#ifdef CONFIG_DEBUG_FS
 #include <linux/pm.h>
 #include <linux/device.h>
 #include <linux/debugfs.h>
@@ -1784,4 +2058,4 @@ static void __exit pm_genpd_debug_exit(void)
 	debugfs_remove_recursive(pm_genpd_debugfs_dir);
 }
 __exitcall(pm_genpd_debug_exit);
-#endif /* CONFIG_PM_ADVANCED_DEBUG */
+#endif /* CONFIG_DEBUG_FS */

drivers/soc/samsung/pm_domains.c

@@ -215,29 +215,22 @@ static __init int exynos4_pm_init_power_domain(void)
 
 	/* Assign the child power domains to their parents */
 	for_each_matching_node(np, exynos_pm_domain_of_match) {
-		struct generic_pm_domain *child_domain, *parent_domain;
-		struct of_phandle_args args;
+		struct of_phandle_args child, parent;
 
-		args.np = np;
-		args.args_count = 0;
-		child_domain = of_genpd_get_from_provider(&args);
-		if (IS_ERR(child_domain))
-			continue;
+		child.np = np;
+		child.args_count = 0;
 
 		if (of_parse_phandle_with_args(np, "power-domains",
-					 "#power-domain-cells", 0, &args) != 0)
-			continue;
-
-		parent_domain = of_genpd_get_from_provider(&args);
-		if (IS_ERR(parent_domain))
+					       "#power-domain-cells", 0,
+					       &parent) != 0)
 			continue;
 
-		if (pm_genpd_add_subdomain(parent_domain, child_domain))
+		if (of_genpd_add_subdomain(&parent, &child))
 			pr_warn("%s failed to add subdomain: %s\n",
-				parent_domain->name, child_domain->name);
+				parent.np->name, child.np->name);
 		else
 			pr_info("%s has as child subdomain: %s.\n",
-				parent_domain->name, child_domain->name);
+				parent.np->name, child.np->name);
 	}
 
 	return 0;

drivers/staging/board/board.c

@@ -140,7 +140,6 @@ static int board_staging_add_dev_domain(struct platform_device *pdev,
 					const char *domain)
 {
 	struct of_phandle_args pd_args;
-	struct generic_pm_domain *pd;
 	struct device_node *np;
 
 	np = of_find_node_by_path(domain);
@@ -151,14 +150,8 @@ static int board_staging_add_dev_domain(struct platform_device *pdev,
 
 	pd_args.np = np;
 	pd_args.args_count = 0;
-	pd = of_genpd_get_from_provider(&pd_args);
-	if (IS_ERR(pd)) {
-		pr_err("Cannot find genpd %s (%ld)\n", domain, PTR_ERR(pd));
-		return PTR_ERR(pd);
-	}
-	pr_debug("Found genpd %s for device %s\n", pd->name, pdev->name);
 
-	return pm_genpd_add_device(pd, &pdev->dev);
+	return of_genpd_add_device(&pd_args, &pdev->dev);
 }
 #else
 static inline int board_staging_add_dev_domain(struct platform_device *pdev,

include/linux/pm_domain.h

@@ -51,6 +51,8 @@ struct generic_pm_domain {
 	struct mutex lock;
 	struct dev_power_governor *gov;
 	struct work_struct power_off_work;
+	struct fwnode_handle *provider;	/* Identity of the domain provider */
+	bool has_provider;
 	const char *name;
 	atomic_t sd_count;	/* Number of subdomains with power "on" */
 	enum gpd_status status;	/* Current state of the domain */
@@ -116,7 +118,6 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 	return to_gpd_data(dev->power.subsys_data->domain_data);
 }
 
-extern struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev);
 extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
 				 struct device *dev,
 				 struct gpd_timing_data *td);
@@ -129,6 +130,7 @@ extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 				     struct generic_pm_domain *target);
 extern int pm_genpd_init(struct generic_pm_domain *genpd,
 			 struct dev_power_governor *gov, bool is_off);
+extern int pm_genpd_remove(struct generic_pm_domain *genpd);
 
 extern struct dev_power_governor simple_qos_governor;
 extern struct dev_power_governor pm_domain_always_on_gov;
@@ -138,10 +140,6 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
 {
 	return ERR_PTR(-ENOSYS);
 }
-static inline struct generic_pm_domain *pm_genpd_lookup_dev(struct device *dev)
-{
-	return NULL;
-}
 static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd,
 					struct device *dev,
 					struct gpd_timing_data *td)
@@ -168,6 +166,10 @@ static inline int pm_genpd_init(struct generic_pm_domain *genpd,
 {
 	return -ENOSYS;
 }
+static inline int pm_genpd_remove(struct generic_pm_domain *genpd)
+{
+	return -ENOTSUPP;
+}
 #endif
 
 static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
@@ -192,58 +194,58 @@ struct genpd_onecell_data {
 	unsigned int num_domains;
 };
 
-typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args,
-						void *data);
-
 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
-int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
-			void *data);
+int of_genpd_add_provider_simple(struct device_node *np,
+				 struct generic_pm_domain *genpd);
+int of_genpd_add_provider_onecell(struct device_node *np,
+				  struct genpd_onecell_data *data);
 void of_genpd_del_provider(struct device_node *np);
-struct generic_pm_domain *of_genpd_get_from_provider(
-			struct of_phandle_args *genpdspec);
-
-struct generic_pm_domain *__of_genpd_xlate_simple(
-					struct of_phandle_args *genpdspec,
-					void *data);
-struct generic_pm_domain *__of_genpd_xlate_onecell(
-					struct of_phandle_args *genpdspec,
-					void *data);
+extern int of_genpd_add_device(struct of_phandle_args *args,
+			       struct device *dev);
+extern int of_genpd_add_subdomain(struct of_phandle_args *parent,
+				  struct of_phandle_args *new_subdomain);
+extern struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
 
 int genpd_dev_pm_attach(struct device *dev);
 #else /* !CONFIG_PM_GENERIC_DOMAINS_OF */
-static inline int __of_genpd_add_provider(struct device_node *np,
-					genpd_xlate_t xlate, void *data)
+static inline int of_genpd_add_provider_simple(struct device_node *np,
+					struct generic_pm_domain *genpd)
 {
-	return 0;
+	return -ENOTSUPP;
 }
-static inline void of_genpd_del_provider(struct device_node *np) {}
 
-static inline struct generic_pm_domain *of_genpd_get_from_provider(
-			struct of_phandle_args *genpdspec)
+static inline int of_genpd_add_provider_onecell(struct device_node *np,
+					struct genpd_onecell_data *data)
 {
-	return NULL;
+	return -ENOTSUPP;
 }
 
-#define __of_genpd_xlate_simple		NULL
-#define __of_genpd_xlate_onecell	NULL
+static inline void of_genpd_del_provider(struct device_node *np) {}
 
-static inline int genpd_dev_pm_attach(struct device *dev)
+static inline int of_genpd_add_device(struct of_phandle_args *args,
+				      struct device *dev)
 {
 	return -ENODEV;
 }
-#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
 
-static inline int of_genpd_add_provider_simple(struct device_node *np,
-					struct generic_pm_domain *genpd)
+static inline int of_genpd_add_subdomain(struct of_phandle_args *parent,
+					 struct of_phandle_args *new_subdomain)
 {
-	return __of_genpd_add_provider(np, __of_genpd_xlate_simple, genpd);
+	return -ENODEV;
 }
-static inline int of_genpd_add_provider_onecell(struct device_node *np,
-					struct genpd_onecell_data *data)
+
+static inline int genpd_dev_pm_attach(struct device *dev)
 {
-	return __of_genpd_add_provider(np, __of_genpd_xlate_onecell, data);
+	return -ENODEV;
 }
 
+static inline
+struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
+
 #ifdef CONFIG_PM
 extern int dev_pm_domain_attach(struct device *dev, bool power_on);
 extern void dev_pm_domain_detach(struct device *dev, bool power_off);