1 files changed, 461 insertions, 72 deletions

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 472c88ae1c0f..c7698cfaa4e8 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -2,104 +2,375 @@
 /*
  * System Control and Management Interface (SCMI) Message Protocol bus layer
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/atomic.h>
 #include <linux/types.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/device.h>
 
 #include "common.h"
 
+#define SCMI_UEVENT_MODALIAS_FMT	"%s:%02x:%s"
+
+BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh);
+EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
+
 static DEFINE_IDA(scmi_bus_id);
-static DEFINE_IDR(scmi_protocols);
-static DEFINE_SPINLOCK(protocol_lock);
 
-static const struct scmi_device_id *
-scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
+static DEFINE_IDR(scmi_requested_devices);
+/* Protect access to scmi_requested_devices */
+static DEFINE_MUTEX(scmi_requested_devices_mtx);
+
+struct scmi_requested_dev {
+	const struct scmi_device_id *id_table;
+	struct list_head node;
+};
+
+/* Track globally the creation of SCMI SystemPower related devices */
+static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
+
+/**
+ * scmi_protocol_device_request  - Helper to request a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be created.
+ *
+ * This helper let an SCMI driver request specific devices identified by the
+ * @id_table to be created for each active SCMI instance.
+ *
+ * The requested device name MUST NOT be already existent for this protocol;
+ * at first the freshly requested @id_table is annotated in the IDR table
+ * @scmi_requested_devices and then the requested device is advertised to any
+ * registered party via the @scmi_requested_devices_nh notification chain.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 {
-	const struct scmi_device_id *id = scmi_drv->id_table;
+	int ret = 0;
+	struct list_head *head, *phead = NULL;
+	struct scmi_requested_dev *rdev;
 
-	if (!id)
-		return NULL;
+	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
 
-	for (; id->protocol_id; id++)
-		if (id->protocol_id == scmi_dev->protocol_id)
-			return id;
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) &&
+	    !IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX)) {
+		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+			id_table->name, id_table->protocol_id);
+		return -EINVAL;
+	}
+
+	/*
+	 * Find the matching protocol rdev list and then search of any
+	 * existent equally named device...fails if any duplicate found.
+	 */
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		head = phead;
+		list_for_each_entry(rdev, head, node) {
+			if (!strcmp(rdev->id_table->name, id_table->name)) {
+				pr_err("Ignoring duplicate request [%d] %s\n",
+				       rdev->id_table->protocol_id,
+				       rdev->id_table->name);
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	/*
+	 * No duplicate found for requested id_table, so let's create a new
+	 * requested device entry for this new valid request.
+	 */
+	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (!rdev) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	rdev->id_table = id_table;
+
+	/*
+	 * Append the new requested device table descriptor to the head of the
+	 * related protocol list, eventually creating such head if not already
+	 * there.
+	 */
+	if (!phead) {
+		phead = kzalloc(sizeof(*phead), GFP_KERNEL);
+		if (!phead) {
+			kfree(rdev);
+			ret = -ENOMEM;
+			goto out;
+		}
+		INIT_LIST_HEAD(phead);
+
+		ret = idr_alloc(&scmi_requested_devices, (void *)phead,
+				id_table->protocol_id,
+				id_table->protocol_id + 1, GFP_KERNEL);
+		if (ret != id_table->protocol_id) {
+			pr_err("Failed to save SCMI device - ret:%d\n", ret);
+			kfree(rdev);
+			kfree(phead);
+			ret = -EINVAL;
+			goto out;
+		}
+		ret = 0;
+	}
+	list_add(&rdev->node, phead);
+
+out:
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	if (!ret)
+		blocking_notifier_call_chain(&scmi_requested_devices_nh,
+					     SCMI_BUS_NOTIFY_DEVICE_REQUEST,
+					     (void *)rdev->id_table);
 
-	return NULL;
+	return ret;
 }
 
-static int scmi_dev_match(struct device *dev, struct device_driver *drv)
+static int scmi_protocol_table_register(const struct scmi_device_id *id_table)
 {
-	struct scmi_driver *scmi_drv = to_scmi_driver(drv);
-	struct scmi_device *scmi_dev = to_scmi_dev(dev);
-	const struct scmi_device_id *id;
+	int ret = 0;
+	const struct scmi_device_id *entry;
 
-	id = scmi_dev_match_id(scmi_dev, scmi_drv);
-	if (id)
-		return 1;
+	for (entry = id_table; entry->name && ret == 0; entry++)
+		ret = scmi_protocol_device_request(entry);
 
+	return ret;
+}
+
+/**
+ * scmi_protocol_device_unrequest  - Helper to unrequest a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be unrequested.
+ *
+ * The unrequested device, described by the provided id_table, is at first
+ * removed from the IDR @scmi_requested_devices and then the removal is
+ * advertised to any registered party via the @scmi_requested_devices_nh
+ * notification chain.
+ */
+static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
+{
+	struct list_head *phead;
+
+	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		struct scmi_requested_dev *victim, *tmp;
+
+		list_for_each_entry_safe(victim, tmp, phead, node) {
+			if (!strcmp(victim->id_table->name, id_table->name)) {
+				list_del(&victim->node);
+
+				mutex_unlock(&scmi_requested_devices_mtx);
+				blocking_notifier_call_chain(&scmi_requested_devices_nh,
+							     SCMI_BUS_NOTIFY_DEVICE_UNREQUEST,
+							     (void *)victim->id_table);
+				kfree(victim);
+				mutex_lock(&scmi_requested_devices_mtx);
+				break;
+			}
+		}
+
+		if (list_empty(phead)) {
+			idr_remove(&scmi_requested_devices,
+				   id_table->protocol_id);
+			kfree(phead);
+		}
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
+}
+
+static void
+scmi_protocol_table_unregister(const struct scmi_device_id *id_table)
+{
+	const struct scmi_device_id *entry;
+
+	for (entry = id_table; entry->name; entry++)
+		scmi_protocol_device_unrequest(entry);
+}
+
+static int scmi_dev_match_by_id_table(struct scmi_device *scmi_dev,
+				      const struct scmi_device_id *id_table)
+{
+	if (!id_table || !id_table->name)
+		return 0;
+
+	/* Always skip transport devices from matching */
+	for (; id_table->protocol_id && id_table->name; id_table++)
+		if (id_table->protocol_id == scmi_dev->protocol_id &&
+		    strncmp(scmi_dev->name, "__scmi_transport_device", 23) &&
+		    !strcmp(id_table->name, scmi_dev->name))
+			return 1;
 	return 0;
 }
 
-static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle)
+static int scmi_dev_match_id(struct scmi_device *scmi_dev,
+			     const struct scmi_driver *scmi_drv)
+{
+	return scmi_dev_match_by_id_table(scmi_dev, scmi_drv->id_table);
+}
+
+static int scmi_dev_match(struct device *dev, const struct device_driver *drv)
 {
-	scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id);
+	const struct scmi_driver *scmi_drv = to_scmi_driver(drv);
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 
-	if (unlikely(!fn))
-		return -EINVAL;
-	return fn(handle);
+	return scmi_dev_match_id(scmi_dev, scmi_drv);
+}
+
+static int scmi_match_by_id_table(struct device *dev, const void *data)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+	const struct scmi_device_id *id_table = data;
+
+	return scmi_dev_match_by_id_table(scmi_dev, id_table);
+}
+
+static struct scmi_device *scmi_child_dev_find(struct device *parent,
+					       int prot_id, const char *name)
+{
+	struct scmi_device_id id_table[2] = { 0 };
+	struct device *dev;
+
+	id_table[0].protocol_id = prot_id;
+	id_table[0].name = name;
+
+	dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
+	if (!dev)
+		return NULL;
+
+	/* Drop the refcnt bumped implicitly by device_find_child */
+	put_device(dev);
+
+	return to_scmi_dev(dev);
 }
 
 static int scmi_dev_probe(struct device *dev)
 {
 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
-	const struct scmi_device_id *id;
-	int ret;
-
-	id = scmi_dev_match_id(scmi_dev, scmi_drv);
-	if (!id)
-		return -ENODEV;
 
 	if (!scmi_dev->handle)
 		return -EPROBE_DEFER;
 
-	ret = scmi_protocol_init(scmi_dev->protocol_id, scmi_dev->handle);
-	if (ret)
-		return ret;
-
 	return scmi_drv->probe(scmi_dev);
 }
 
-static int scmi_dev_remove(struct device *dev)
+static void scmi_dev_remove(struct device *dev)
 {
 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 
 	if (scmi_drv->remove)
 		scmi_drv->remove(scmi_dev);
+}
+
+static int scmi_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return add_uevent_var(env, "MODALIAS=" SCMI_UEVENT_MODALIAS_FMT,
+			      dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			      scmi_dev->name);
+}
+
+static ssize_t modalias_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sysfs_emit(buf, SCMI_UEVENT_MODALIAS_FMT,
+			  dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+			  scmi_dev->name);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t protocol_id_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "0x%02x\n", scmi_dev->protocol_id);
+}
+static DEVICE_ATTR_RO(protocol_id);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	return sprintf(buf, "%s\n", scmi_dev->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *scmi_device_attributes_attrs[] = {
+	&dev_attr_protocol_id.attr,
+	&dev_attr_name.attr,
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(scmi_device_attributes);
+
+static int scmi_pm_suspend(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+
+	if (drv && drv->pm && drv->pm->suspend)
+		return drv->pm->suspend(dev);
 
 	return 0;
 }
 
-static struct bus_type scmi_bus_type = {
+static int scmi_pm_resume(struct device *dev)
+{
+	const struct device_driver *drv = dev->driver;
+
+	if (drv && drv->pm && drv->pm->resume)
+		return drv->pm->resume(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops scmi_dev_pm_ops = {
+	.suspend = pm_sleep_ptr(scmi_pm_suspend),
+	.resume = pm_sleep_ptr(scmi_pm_resume),
+};
+
+const struct bus_type scmi_bus_type = {
 	.name =	"scmi_protocol",
 	.match = scmi_dev_match,
 	.probe = scmi_dev_probe,
 	.remove = scmi_dev_remove,
+	.uevent	= scmi_device_uevent,
+	.dev_groups = scmi_device_attributes_groups,
+	.pm = &scmi_dev_pm_ops,
 };
+EXPORT_SYMBOL_GPL(scmi_bus_type);
 
 int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 			 const char *mod_name)
 {
 	int retval;
 
+	if (!driver->probe)
+		return -EINVAL;
+
+	retval = scmi_protocol_table_register(driver->id_table);
+	if (retval)
+		return retval;
+
 	driver->driver.bus = &scmi_bus_type;
 	driver->driver.name = driver->name;
 	driver->driver.owner = owner;
@@ -107,7 +378,7 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 
 	retval = driver_register(&driver->driver);
 	if (!retval)
-		pr_debug("registered new scmi driver %s\n", driver->name);
+		pr_debug("Registered new scmi driver %s\n", driver->name);
 
 	return retval;
 }
@@ -116,84 +387,191 @@ EXPORT_SYMBOL_GPL(scmi_driver_register);
 void scmi_driver_unregister(struct scmi_driver *driver)
 {
 	driver_unregister(&driver->driver);
+	scmi_protocol_table_unregister(driver->id_table);
 }
 EXPORT_SYMBOL_GPL(scmi_driver_unregister);
 
-struct scmi_device *
-scmi_device_create(struct device_node *np, struct device *parent, int protocol)
+static void scmi_device_release(struct device *dev)
+{
+	struct scmi_device *scmi_dev = to_scmi_dev(dev);
+
+	kfree_const(scmi_dev->name);
+	kfree(scmi_dev);
+}
+
+static void __scmi_device_destroy(struct scmi_device *scmi_dev)
+{
+	pr_debug("(%pOF) Destroying SCMI device '%s' for protocol 0x%x (%s)\n",
+		 scmi_dev->dev.parent->of_node,
+		 dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+		 scmi_dev->name);
+
+	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
+		atomic_set(&scmi_syspower_registered, 0);
+
+	ida_free(&scmi_bus_id, scmi_dev->id);
+	device_unregister(&scmi_dev->dev);
+}
+
+static struct scmi_device *
+__scmi_device_create(struct device_node *np, struct device *parent,
+		     int protocol, const char *name)
 {
 	int id, retval;
 	struct scmi_device *scmi_dev;
 
+	/*
+	 * If the same protocol/name device already exist under the same parent
+	 * (i.e. SCMI instance) just return the existent device.
+	 * This avoids any race between the SCMI driver, creating devices for
+	 * each DT defined protocol at probe time, and the concurrent
+	 * registration of SCMI drivers.
+	 */
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		return scmi_dev;
+
+	/*
+	 * Ignore any possible subsequent failures while creating the device
+	 * since we are doomed anyway at that point; not using a mutex which
+	 * spans across this whole function to keep things simple and to avoid
+	 * to serialize all the __scmi_device_create calls across possibly
+	 * different SCMI server instances (parent)
+	 */
+	if (protocol == SCMI_PROTOCOL_SYSTEM &&
+	    atomic_cmpxchg(&scmi_syspower_registered, 0, 1)) {
+		dev_warn(parent,
+			 "SCMI SystemPower protocol device must be unique !\n");
+		return NULL;
+	}
+
 	scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
 	if (!scmi_dev)
 		return NULL;
 
-	id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
-	if (id < 0)
-		goto free_mem;
+	scmi_dev->name = kstrdup_const(name ?: "unknown", GFP_KERNEL);
+	if (!scmi_dev->name) {
+		kfree(scmi_dev);
+		return NULL;
+	}
+
+	id = ida_alloc_min(&scmi_bus_id, 1, GFP_KERNEL);
+	if (id < 0) {
+		kfree_const(scmi_dev->name);
+		kfree(scmi_dev);
+		return NULL;
+	}
 
 	scmi_dev->id = id;
 	scmi_dev->protocol_id = protocol;
 	scmi_dev->dev.parent = parent;
-	scmi_dev->dev.of_node = np;
+	device_set_node(&scmi_dev->dev, of_fwnode_handle(np));
 	scmi_dev->dev.bus = &scmi_bus_type;
+	scmi_dev->dev.release = scmi_device_release;
 	dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);
 
 	retval = device_register(&scmi_dev->dev);
 	if (retval)
 		goto put_dev;
 
+	pr_debug("(%pOF) Created SCMI device '%s' for protocol 0x%x (%s)\n",
+		 parent->of_node, dev_name(&scmi_dev->dev), protocol, name);
+
 	return scmi_dev;
 put_dev:
 	put_device(&scmi_dev->dev);
-	ida_simple_remove(&scmi_bus_id, id);
-free_mem:
-	kfree(scmi_dev);
+	ida_free(&scmi_bus_id, id);
 	return NULL;
 }
 
-void scmi_device_destroy(struct scmi_device *scmi_dev)
+static struct scmi_device *
+_scmi_device_create(struct device_node *np, struct device *parent,
+		    int protocol, const char *name)
 {
-	scmi_handle_put(scmi_dev->handle);
-	device_unregister(&scmi_dev->dev);
-	ida_simple_remove(&scmi_bus_id, scmi_dev->id);
-	kfree(scmi_dev);
-}
+	struct scmi_device *sdev;
 
-void scmi_set_handle(struct scmi_device *scmi_dev)
-{
-	scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
+	sdev = __scmi_device_create(np, parent, protocol, name);
+	if (!sdev)
+		pr_err("(%pOF) Failed to create device for protocol 0x%x (%s)\n",
+		       parent->of_node, protocol, name);
+
+	return sdev;
 }
 
-int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
+/**
+ * scmi_device_create  - A method to create one or more SCMI devices
+ *
+ * @np: A reference to the device node to use for the new device(s)
+ * @parent: The parent device to use identifying a specific SCMI instance
+ * @protocol: The SCMI protocol to be associated with this device
+ * @name: The requested-name of the device to be created; this is optional
+ *	  and if no @name is provided, all the devices currently known to
+ *	  be requested on the SCMI bus for @protocol will be created.
+ *
+ * This method can be invoked to create a single well-defined device (like
+ * a transport device or a device requested by an SCMI driver loaded after
+ * the core SCMI stack has been probed), or to create all the devices currently
+ * known to have been requested by the loaded SCMI drivers for a specific
+ * protocol (typically during SCMI core protocol enumeration at probe time).
+ *
+ * Return: The created device (or one of them if @name was NOT provided and
+ *	   multiple devices were created) or NULL if no device was created;
+ *	   note that NULL indicates an error ONLY in case a specific @name
+ *	   was provided: when @name param was not provided, a number of devices
+ *	   could have been potentially created for a whole protocol, unless no
+ *	   device was found to have been requested for that specific protocol.
+ */
+struct scmi_device *scmi_device_create(struct device_node *np,
+				       struct device *parent, int protocol,
+				       const char *name)
 {
-	int ret;
+	struct list_head *phead;
+	struct scmi_requested_dev *rdev;
+	struct scmi_device *scmi_dev = NULL;
+
+	if (name)
+		return _scmi_device_create(np, parent, protocol, name);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, protocol);
+	/* Nothing to do. */
+	if (!phead) {
+		mutex_unlock(&scmi_requested_devices_mtx);
+		return NULL;
+	}
 
-	spin_lock(&protocol_lock);
-	ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1,
-			GFP_ATOMIC);
-	spin_unlock(&protocol_lock);
-	if (ret != protocol_id)
-		pr_err("unable to allocate SCMI idr slot, err %d\n", ret);
+	/* Walk the list of requested devices for protocol and create them */
+	list_for_each_entry(rdev, phead, node) {
+		struct scmi_device *sdev;
 
-	return ret;
+		sdev = _scmi_device_create(np, parent,
+					   rdev->id_table->protocol_id,
+					   rdev->id_table->name);
+		if (sdev)
+			scmi_dev = sdev;
+	}
+
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	return scmi_dev;
 }
-EXPORT_SYMBOL_GPL(scmi_protocol_register);
+EXPORT_SYMBOL_GPL(scmi_device_create);
 
-void scmi_protocol_unregister(int protocol_id)
+void scmi_device_destroy(struct device *parent, int protocol, const char *name)
 {
-	spin_lock(&protocol_lock);
-	idr_remove(&scmi_protocols, protocol_id);
-	spin_unlock(&protocol_lock);
+	struct scmi_device *scmi_dev;
+
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		__scmi_device_destroy(scmi_dev);
 }
-EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
+EXPORT_SYMBOL_GPL(scmi_device_destroy);
 
 static int __scmi_devices_unregister(struct device *dev, void *data)
 {
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 
-	scmi_device_destroy(scmi_dev);
+	__scmi_device_destroy(scmi_dev);
 	return 0;
 }
 
@@ -208,7 +586,9 @@ static int __init scmi_bus_init(void)
 
 	retval = bus_register(&scmi_bus_type);
 	if (retval)
-		pr_err("scmi protocol bus register failed (%d)\n", retval);
+		pr_err("SCMI protocol bus register failed (%d)\n", retval);
+
+	pr_info("SCMI protocol bus registered\n");
 
 	return retval;
 }
@@ -216,8 +596,17 @@ subsys_initcall(scmi_bus_init);
 
 static void __exit scmi_bus_exit(void)
 {
+	/*
+	 * Destroy all remaining devices: just in case the drivers were
+	 * manually unbound and at first and then the modules unloaded.
+	 */
 	scmi_devices_unregister();
 	bus_unregister(&scmi_bus_type);
 	ida_destroy(&scmi_bus_id);
 }
 module_exit(scmi_bus_exit);
+
+MODULE_ALIAS("scmi-core");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI protocol bus");
+MODULE_LICENSE("GPL");