1 files changed, 670 insertions, 342 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 357b6ae4d207..eef1c6b46ad8 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -30,276 +30,29 @@
 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
 
-static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	struct mei_cl_driver *driver = to_mei_cl_driver(drv);
-	const struct mei_cl_device_id *id;
-	const uuid_le *uuid;
-	const char *name;
-
-	if (!device)
-		return 0;
-
-	uuid = mei_me_cl_uuid(device->me_cl);
-	name = device->name;
-
-	if (!driver || !driver->id_table)
-		return 0;
-
-	id = driver->id_table;
-
-	while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
-
-		if (!uuid_le_cmp(*uuid, id->uuid)) {
-			if (id->name[0]) {
-				if (!strncmp(name, id->name, sizeof(id->name)))
-					return 1;
-			} else {
-				return 1;
-			}
-		}
-
-		id++;
-	}
-
-	return 0;
-}
-
-static int mei_cl_device_probe(struct device *dev)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	struct mei_cl_driver *driver;
-	struct mei_cl_device_id id;
-
-	if (!device)
-		return 0;
-
-	driver = to_mei_cl_driver(dev->driver);
-	if (!driver || !driver->probe)
-		return -ENODEV;
-
-	dev_dbg(dev, "Device probe\n");
-
-	strlcpy(id.name, device->name, sizeof(id.name));
-
-	return driver->probe(device, &id);
-}
-
-static int mei_cl_device_remove(struct device *dev)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	struct mei_cl_driver *driver;
-
-	if (!device || !dev->driver)
-		return 0;
-
-	if (device->event_cb) {
-		device->event_cb = NULL;
-		cancel_work_sync(&device->event_work);
-	}
-
-	driver = to_mei_cl_driver(dev->driver);
-	if (!driver->remove) {
-		dev->driver = NULL;
-
-		return 0;
-	}
-
-	return driver->remove(device);
-}
-
-static ssize_t name_show(struct device *dev, struct device_attribute *a,
-			     char *buf)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	size_t len;
-
-	len = snprintf(buf, PAGE_SIZE, "%s", device->name);
-
-	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
-}
-static DEVICE_ATTR_RO(name);
-
-static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
-			     char *buf)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	const uuid_le *uuid = mei_me_cl_uuid(device->me_cl);
-	size_t len;
-
-	len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
-
-	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
-}
-static DEVICE_ATTR_RO(uuid);
-
-static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
-			     char *buf)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	const uuid_le *uuid = mei_me_cl_uuid(device->me_cl);
-	size_t len;
-
-	len = snprintf(buf, PAGE_SIZE, "mei:%s:" MEI_CL_UUID_FMT ":",
-		device->name, MEI_CL_UUID_ARGS(uuid->b));
-
-	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
-}
-static DEVICE_ATTR_RO(modalias);
-
-static struct attribute *mei_cl_dev_attrs[] = {
-	&dev_attr_name.attr,
-	&dev_attr_uuid.attr,
-	&dev_attr_modalias.attr,
-	NULL,
-};
-ATTRIBUTE_GROUPS(mei_cl_dev);
-
-static int mei_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-	const uuid_le *uuid = mei_me_cl_uuid(device->me_cl);
-
-	if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
-		return -ENOMEM;
-
-	if (add_uevent_var(env, "MEI_CL_NAME=%s", device->name))
-		return -ENOMEM;
-
-	if (add_uevent_var(env, "MODALIAS=mei:%s:" MEI_CL_UUID_FMT ":",
-		device->name, MEI_CL_UUID_ARGS(uuid->b)))
-		return -ENOMEM;
-
-	return 0;
-}
-
-static struct bus_type mei_cl_bus_type = {
-	.name		= "mei",
-	.dev_groups	= mei_cl_dev_groups,
-	.match		= mei_cl_device_match,
-	.probe		= mei_cl_device_probe,
-	.remove		= mei_cl_device_remove,
-	.uevent		= mei_cl_uevent,
-};
-
-static void mei_cl_dev_release(struct device *dev)
-{
-	struct mei_cl_device *device = to_mei_cl_device(dev);
-
-	if (!device)
-		return;
-
-	mei_me_cl_put(device->me_cl);
-	kfree(device);
-}
-
-static struct device_type mei_cl_device_type = {
-	.release	= mei_cl_dev_release,
-};
-
-struct mei_cl *mei_cl_bus_find_cl_by_uuid(struct mei_device *dev,
-					 uuid_le uuid)
-{
-	struct mei_cl *cl;
-
-	list_for_each_entry(cl, &dev->device_list, device_link) {
-		if (cl->device && cl->device->me_cl &&
-		    !uuid_le_cmp(uuid, *mei_me_cl_uuid(cl->device->me_cl)))
-			return cl;
-	}
-
-	return NULL;
-}
-
-struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
-					struct mei_me_client *me_cl,
-					struct mei_cl *cl,
-					char *name)
-{
-	struct mei_cl_device *device;
-	int status;
-
-	device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
-	if (!device)
-		return NULL;
-
-	device->me_cl = mei_me_cl_get(me_cl);
-	if (!device->me_cl) {
-		kfree(device);
-		return NULL;
-	}
-
-	device->cl = cl;
-	device->dev.parent = dev->dev;
-	device->dev.bus = &mei_cl_bus_type;
-	device->dev.type = &mei_cl_device_type;
-
-	strlcpy(device->name, name, sizeof(device->name));
-
-	dev_set_name(&device->dev, "mei:%s:%pUl", name, mei_me_cl_uuid(me_cl));
-
-	status = device_register(&device->dev);
-	if (status) {
-		dev_err(dev->dev, "Failed to register MEI device\n");
-		mei_me_cl_put(device->me_cl);
-		kfree(device);
-		return NULL;
-	}
-
-	cl->device = device;
-
-	dev_dbg(&device->dev, "client %s registered\n", name);
-
-	return device;
-}
-EXPORT_SYMBOL_GPL(mei_cl_add_device);
-
-void mei_cl_remove_device(struct mei_cl_device *device)
-{
-	device_unregister(&device->dev);
-}
-EXPORT_SYMBOL_GPL(mei_cl_remove_device);
-
-int __mei_cl_driver_register(struct mei_cl_driver *driver, struct module *owner)
-{
-	int err;
-
-	driver->driver.name = driver->name;
-	driver->driver.owner = owner;
-	driver->driver.bus = &mei_cl_bus_type;
-
-	err = driver_register(&driver->driver);
-	if (err)
-		return err;
-
-	pr_debug("mei: driver [%s] registered\n", driver->driver.name);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
-
-void mei_cl_driver_unregister(struct mei_cl_driver *driver)
-{
-	driver_unregister(&driver->driver);
-
-	pr_debug("mei: driver [%s] unregistered\n", driver->driver.name);
-}
-EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
-
+/**
+ * __mei_cl_send - internal client send (write)
+ *
+ * @cl: host client
+ * @buf: buffer to send
+ * @length: buffer length
+ * @blocking: wait for write completion
+ *
+ * Return: written size bytes or < 0 on error
+ */
 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
 			bool blocking)
 {
-	struct mei_device *dev;
+	struct mei_device *bus;
 	struct mei_cl_cb *cb = NULL;
 	ssize_t rets;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
 
-	dev = cl->dev;
+	bus = cl->dev;
 
-	mutex_lock(&dev->device_lock);
+	mutex_lock(&bus->device_lock);
 	if (!mei_cl_is_connected(cl)) {
 		rets = -ENODEV;
 		goto out;
@@ -327,16 +80,25 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
 	rets = mei_cl_write(cl, cb, blocking);
 
 out:
-	mutex_unlock(&dev->device_lock);
+	mutex_unlock(&bus->device_lock);
 	if (rets < 0)
 		mei_io_cb_free(cb);
 
 	return rets;
 }
 
+/**
+ * __mei_cl_recv - internal client receive (read)
+ *
+ * @cl: host client
+ * @buf: buffer to send
+ * @length: buffer length
+ *
+ * Return: read size in bytes of < 0 on error
+ */
 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 {
-	struct mei_device *dev;
+	struct mei_device *bus;
 	struct mei_cl_cb *cb;
 	size_t r_length;
 	ssize_t rets;
@@ -344,9 +106,9 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
 
-	dev = cl->dev;
+	bus = cl->dev;
 
-	mutex_lock(&dev->device_lock);
+	mutex_lock(&bus->device_lock);
 
 	cb = mei_cl_read_cb(cl, NULL);
 	if (cb)
@@ -356,9 +118,10 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 	if (rets && rets != -EBUSY)
 		goto out;
 
+	/* wait on event only if there is no other waiter */
 	if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
 
-		mutex_unlock(&dev->device_lock);
+		mutex_unlock(&bus->device_lock);
 
 		if (wait_event_interruptible(cl->rx_wait,
 				(!list_empty(&cl->rd_completed)) ||
@@ -369,7 +132,7 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 			return -ERESTARTSYS;
 		}
 
-		mutex_lock(&dev->device_lock);
+		mutex_lock(&bus->device_lock);
 
 		if (!mei_cl_is_connected(cl)) {
 			rets = -EBUSY;
@@ -396,14 +159,23 @@ copy:
 free:
 	mei_io_cb_free(cb);
 out:
-	mutex_unlock(&dev->device_lock);
+	mutex_unlock(&bus->device_lock);
 
 	return rets;
 }
 
-ssize_t mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
+/**
+ * mei_cl_send - me device send  (write)
+ *
+ * @cldev: me client device
+ * @buf: buffer to send
+ * @length: buffer length
+ *
+ * Return: written size in bytes or < 0 on error
+ */
+ssize_t mei_cl_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 {
-	struct mei_cl *cl = device->cl;
+	struct mei_cl *cl = cldev->cl;
 
 	if (cl == NULL)
 		return -ENODEV;
@@ -412,9 +184,18 @@ ssize_t mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
 }
 EXPORT_SYMBOL_GPL(mei_cl_send);
 
-ssize_t mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
+/**
+ * mei_cl_recv - client receive (read)
+ *
+ * @cldev: me client device
+ * @buf: buffer to send
+ * @length: buffer length
+ *
+ * Return: read size in bytes of < 0 on error
+ */
+ssize_t mei_cl_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 {
-	struct mei_cl *cl = device->cl;
+	struct mei_cl *cl = cldev->cl;
 
 	if (cl == NULL)
 		return -ENODEV;
@@ -423,151 +204,698 @@ ssize_t mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
 }
 EXPORT_SYMBOL_GPL(mei_cl_recv);
 
+/**
+ * mei_bus_event_work  - dispatch rx event for a bus device
+ *    and schedule new work
+ *
+ * @work: work
+ */
 static void mei_bus_event_work(struct work_struct *work)
 {
-	struct mei_cl_device *device;
+	struct mei_cl_device *cldev;
 
-	device = container_of(work, struct mei_cl_device, event_work);
+	cldev = container_of(work, struct mei_cl_device, event_work);
 
-	if (device->event_cb)
-		device->event_cb(device, device->events, device->event_context);
+	if (cldev->event_cb)
+		cldev->event_cb(cldev, cldev->events, cldev->event_context);
 
-	device->events = 0;
+	cldev->events = 0;
 
 	/* Prepare for the next read */
-	mei_cl_read_start(device->cl, 0, NULL);
+	if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
+		mei_cl_read_start(cldev->cl, 0, NULL);
 }
 
-int mei_cl_register_event_cb(struct mei_cl_device *device,
+/**
+ * mei_cl_bus_notify_event - schedule notify cb on bus client
+ *
+ * @cl: host client
+ */
+void mei_cl_bus_notify_event(struct mei_cl *cl)
+{
+	struct mei_cl_device *cldev = cl->cldev;
+
+	if (!cldev || !cldev->event_cb)
+		return;
+
+	if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
+		return;
+
+	if (!cl->notify_ev)
+		return;
+
+	set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
+
+	schedule_work(&cldev->event_work);
+
+	cl->notify_ev = false;
+}
+
+/**
+ * mei_cl_bus_rx_event  - schedule rx evenet
+ *
+ * @cl: host client
+ */
+void mei_cl_bus_rx_event(struct mei_cl *cl)
+{
+	struct mei_cl_device *cldev = cl->cldev;
+
+	if (!cldev || !cldev->event_cb)
+		return;
+
+	if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
+		return;
+
+	set_bit(MEI_CL_EVENT_RX, &cldev->events);
+
+	schedule_work(&cldev->event_work);
+}
+
+/**
+ * mei_cl_register_event_cb - register event callback
+ *
+ * @cldev: me client devices
+ * @event_cb: callback function
+ * @events_mask: requested events bitmask
+ * @context: driver context data
+ *
+ * Return: 0 on success
+ *         -EALREADY if an callback is already registered
+ *         <0 on other errors
+ */
+int mei_cl_register_event_cb(struct mei_cl_device *cldev,
+			  unsigned long events_mask,
 			  mei_cl_event_cb_t event_cb, void *context)
 {
-	if (device->event_cb)
+	int ret;
+
+	if (cldev->event_cb)
 		return -EALREADY;
 
-	device->events = 0;
-	device->event_cb = event_cb;
-	device->event_context = context;
-	INIT_WORK(&device->event_work, mei_bus_event_work);
+	cldev->events = 0;
+	cldev->events_mask = events_mask;
+	cldev->event_cb = event_cb;
+	cldev->event_context = context;
+	INIT_WORK(&cldev->event_work, mei_bus_event_work);
 
-	mei_cl_read_start(device->cl, 0, NULL);
+	if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
+		ret = mei_cl_read_start(cldev->cl, 0, NULL);
+		if (ret && ret != -EBUSY)
+			return ret;
+	}
+
+	if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
+		mutex_lock(&cldev->cl->dev->device_lock);
+		ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
+		mutex_unlock(&cldev->cl->dev->device_lock);
+		if (ret)
+			return ret;
+	}
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
 
-void *mei_cl_get_drvdata(const struct mei_cl_device *device)
+/**
+ * mei_cl_get_drvdata - driver data getter
+ *
+ * @cldev: mei client device
+ *
+ * Return: driver private data
+ */
+void *mei_cl_get_drvdata(const struct mei_cl_device *cldev)
 {
-	return dev_get_drvdata(&device->dev);
+	return dev_get_drvdata(&cldev->dev);
 }
 EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
 
-void mei_cl_set_drvdata(struct mei_cl_device *device, void *data)
+/**
+ * mei_cl_set_drvdata - driver data setter
+ *
+ * @cldev: mei client device
+ * @data: data to store
+ */
+void mei_cl_set_drvdata(struct mei_cl_device *cldev, void *data)
 {
-	dev_set_drvdata(&device->dev, data);
+	dev_set_drvdata(&cldev->dev, data);
 }
 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
 
-int mei_cl_enable_device(struct mei_cl_device *device)
+/**
+ * mei_cl_enable_device - enable me client device
+ *     create connection with me client
+ *
+ * @cldev: me client device
+ *
+ * Return: 0 on success and < 0 on error
+ */
+int mei_cl_enable_device(struct mei_cl_device *cldev)
 {
-	int err;
-	struct mei_device *dev;
-	struct mei_cl *cl = device->cl;
-
-	if (cl == NULL)
-		return -ENODEV;
-
-	dev = cl->dev;
-
-	mutex_lock(&dev->device_lock);
+	struct mei_device *bus = cldev->bus;
+	struct mei_cl *cl;
+	int ret;
+
+	cl = cldev->cl;
+
+	if (!cl) {
+		mutex_lock(&bus->device_lock);
+		cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
+		mutex_unlock(&bus->device_lock);
+		if (IS_ERR(cl))
+			return PTR_ERR(cl);
+		/* update pointers */
+		cldev->cl = cl;
+		cl->cldev = cldev;
+	}
 
+	mutex_lock(&bus->device_lock);
 	if (mei_cl_is_connected(cl)) {
-		mutex_unlock(&dev->device_lock);
-		dev_warn(dev->dev, "Already connected");
-		return -EBUSY;
+		ret = 0;
+		goto out;
 	}
 
-	err = mei_cl_connect(cl, device->me_cl, NULL);
-	if (err < 0) {
-		mutex_unlock(&dev->device_lock);
-		dev_err(dev->dev, "Could not connect to the ME client");
-
-		return err;
+	if (!mei_me_cl_is_active(cldev->me_cl)) {
+		dev_err(&cldev->dev, "me client is not active\n");
+		ret = -ENOTTY;
+		goto out;
 	}
 
-	mutex_unlock(&dev->device_lock);
+	ret = mei_cl_connect(cl, cldev->me_cl, NULL);
+	if (ret < 0)
+		dev_err(&cldev->dev, "cannot connect\n");
 
-	if (device->event_cb)
-		mei_cl_read_start(device->cl, 0, NULL);
+out:
+	mutex_unlock(&bus->device_lock);
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(mei_cl_enable_device);
 
-int mei_cl_disable_device(struct mei_cl_device *device)
+/**
+ * mei_cl_disable_device - disable me client device
+ *     disconnect form the me client
+ *
+ * @cldev: me client device
+ *
+ * Return: 0 on success and < 0 on error
+ */
+int mei_cl_disable_device(struct mei_cl_device *cldev)
 {
+	struct mei_device *bus;
+	struct mei_cl *cl;
 	int err;
-	struct mei_device *dev;
-	struct mei_cl *cl = device->cl;
 
-	if (cl == NULL)
+	if (!cldev || !cldev->cl)
 		return -ENODEV;
 
-	dev = cl->dev;
+	cl = cldev->cl;
+
+	bus = cldev->bus;
 
-	device->event_cb = NULL;
+	cldev->event_cb = NULL;
 
-	mutex_lock(&dev->device_lock);
+	mutex_lock(&bus->device_lock);
 
 	if (!mei_cl_is_connected(cl)) {
-		dev_err(dev->dev, "Already disconnected");
+		dev_err(bus->dev, "Already disconnected");
 		err = 0;
 		goto out;
 	}
 
 	err = mei_cl_disconnect(cl);
-	if (err < 0) {
-		dev_err(dev->dev, "Could not disconnect from the ME client");
-		goto out;
-	}
+	if (err < 0)
+		dev_err(bus->dev, "Could not disconnect from the ME client");
 
+out:
 	/* Flush queues and remove any pending read */
 	mei_cl_flush_queues(cl, NULL);
+	mei_cl_unlink(cl);
 
-out:
-	mutex_unlock(&dev->device_lock);
-	return err;
+	kfree(cl);
+	cldev->cl = NULL;
 
+	mutex_unlock(&bus->device_lock);
+	return err;
 }
 EXPORT_SYMBOL_GPL(mei_cl_disable_device);
 
-void mei_cl_bus_rx_event(struct mei_cl *cl)
+/**
+ * mei_cl_device_find - find matching entry in the driver id table
+ *
+ * @cldev: me client device
+ * @cldrv: me client driver
+ *
+ * Return: id on success; NULL if no id is matching
+ */
+static const
+struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
+					    struct mei_cl_driver *cldrv)
+{
+	const struct mei_cl_device_id *id;
+	const uuid_le *uuid;
+
+	uuid = mei_me_cl_uuid(cldev->me_cl);
+
+	id = cldrv->id_table;
+	while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
+		if (!uuid_le_cmp(*uuid, id->uuid)) {
+
+			if (!cldev->name[0])
+				return id;
+
+			if (!strncmp(cldev->name, id->name, sizeof(id->name)))
+				return id;
+		}
+
+		id++;
+	}
+
+	return NULL;
+}
+
+/**
+ * mei_cl_device_match  - device match function
+ *
+ * @dev: device
+ * @drv: driver
+ *
+ * Return:  1 if matching device was found 0 otherwise
+ */
+static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
+	const struct mei_cl_device_id *found_id;
+
+	if (!cldev)
+		return 0;
+
+	if (!cldev->do_match)
+		return 0;
+
+	if (!cldrv || !cldrv->id_table)
+		return 0;
+
+	found_id = mei_cl_device_find(cldev, cldrv);
+	if (found_id)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * mei_cl_device_probe - bus probe function
+ *
+ * @dev: device
+ *
+ * Return:  0 on success; < 0 otherwise
+ */
+static int mei_cl_device_probe(struct device *dev)
+{
+	struct mei_cl_device *cldev;
+	struct mei_cl_driver *cldrv;
+	const struct mei_cl_device_id *id;
+
+	cldev = to_mei_cl_device(dev);
+	cldrv = to_mei_cl_driver(dev->driver);
+
+	if (!cldev)
+		return 0;
+
+	if (!cldrv || !cldrv->probe)
+		return -ENODEV;
+
+	id = mei_cl_device_find(cldev, cldrv);
+	if (!id)
+		return -ENODEV;
+
+	__module_get(THIS_MODULE);
+
+	return cldrv->probe(cldev, id);
+}
+
+/**
+ * mei_cl_device_remove - remove device from the bus
+ *
+ * @dev: device
+ *
+ * Return:  0 on success; < 0 otherwise
+ */
+static int mei_cl_device_remove(struct device *dev)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	struct mei_cl_driver *cldrv;
+	int ret = 0;
+
+	if (!cldev || !dev->driver)
+		return 0;
+
+	if (cldev->event_cb) {
+		cldev->event_cb = NULL;
+		cancel_work_sync(&cldev->event_work);
+	}
+
+	cldrv = to_mei_cl_driver(dev->driver);
+	if (cldrv->remove)
+		ret = cldrv->remove(cldev);
+
+	module_put(THIS_MODULE);
+	dev->driver = NULL;
+	return ret;
+
+}
+
+static ssize_t name_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	size_t len;
+
+	len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
+	size_t len;
+
+	len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+static DEVICE_ATTR_RO(uuid);
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
+	size_t len;
+
+	len = snprintf(buf, PAGE_SIZE, "mei:%s:" MEI_CL_UUID_FMT ":",
+		cldev->name, MEI_CL_UUID_ARGS(uuid->b));
+
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *mei_cl_dev_attrs[] = {
+	&dev_attr_name.attr,
+	&dev_attr_uuid.attr,
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(mei_cl_dev);
+
+/**
+ * mei_cl_device_uevent - me client bus uevent handler
+ *
+ * @dev: device
+ * @env: uevent kobject
+ *
+ * Return: 0 on success -ENOMEM on when add_uevent_var fails
+ */
+static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
+
+	if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "MODALIAS=mei:%s:" MEI_CL_UUID_FMT ":",
+		cldev->name, MEI_CL_UUID_ARGS(uuid->b)))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static struct bus_type mei_cl_bus_type = {
+	.name		= "mei",
+	.dev_groups	= mei_cl_dev_groups,
+	.match		= mei_cl_device_match,
+	.probe		= mei_cl_device_probe,
+	.remove		= mei_cl_device_remove,
+	.uevent		= mei_cl_device_uevent,
+};
+
+static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
+{
+	if (bus)
+		get_device(bus->dev);
+
+	return bus;
+}
+
+static void mei_dev_bus_put(struct mei_device *bus)
 {
-	struct mei_cl_device *device = cl->device;
+	if (bus)
+		put_device(bus->dev);
+}
 
-	if (!device || !device->event_cb)
+static void mei_cl_dev_release(struct device *dev)
+{
+	struct mei_cl_device *cldev = to_mei_cl_device(dev);
+
+	if (!cldev)
 		return;
 
-	set_bit(MEI_CL_EVENT_RX, &device->events);
+	mei_me_cl_put(cldev->me_cl);
+	mei_dev_bus_put(cldev->bus);
+	kfree(cldev);
+}
+
+static struct device_type mei_cl_device_type = {
+	.release	= mei_cl_dev_release,
+};
+
+/**
+ * mei_cl_dev_alloc - initialize and allocate mei client device
+ *
+ * @bus: mei device
+ * @me_cl: me client
+ *
+ * Return: allocated device structur or NULL on allocation failure
+ */
+static struct mei_cl_device *mei_cl_dev_alloc(struct mei_device *bus,
+					      struct mei_me_client *me_cl)
+{
+	struct mei_cl_device *cldev;
+
+	cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
+	if (!cldev)
+		return NULL;
+
+	device_initialize(&cldev->dev);
+	cldev->dev.parent = bus->dev;
+	cldev->dev.bus    = &mei_cl_bus_type;
+	cldev->dev.type   = &mei_cl_device_type;
+	cldev->bus        = mei_dev_bus_get(bus);
+	cldev->me_cl      = mei_me_cl_get(me_cl);
+	cldev->is_added   = 0;
+	INIT_LIST_HEAD(&cldev->bus_list);
+
+	return cldev;
+}
+
+/**
+ * mei_cl_dev_setup - setup me client device
+ *    run fix up routines and set the device name
+ *
+ * @bus: mei device
+ * @cldev: me client device
+ *
+ * Return: true if the device is eligible for enumeration
+ */
+static bool mei_cl_dev_setup(struct mei_device *bus,
+			     struct mei_cl_device *cldev)
+{
+	cldev->do_match = 1;
+	mei_cl_dev_fixup(cldev);
+
+	if (cldev->do_match)
+		dev_set_name(&cldev->dev, "mei:%s:%pUl",
+			     cldev->name, mei_me_cl_uuid(cldev->me_cl));
 
-	schedule_work(&device->event_work);
+	return cldev->do_match == 1;
 }
 
-void mei_cl_bus_remove_devices(struct mei_device *dev)
+/**
+ * mei_cl_bus_dev_add - add me client devices
+ *
+ * @cldev: me client device
+ *
+ * Return: 0 on success; < 0 on failre
+ */
+static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 {
-	struct mei_cl *cl, *next;
+	int ret;
+
+	dev_dbg(cldev->bus->dev, "adding %pUL\n", mei_me_cl_uuid(cldev->me_cl));
+	ret = device_add(&cldev->dev);
+	if (!ret)
+		cldev->is_added = 1;
 
-	mutex_lock(&dev->device_lock);
-	list_for_each_entry_safe(cl, next, &dev->device_list, device_link) {
-		if (cl->device)
-			mei_cl_remove_device(cl->device);
+	return ret;
+}
 
-		list_del(&cl->device_link);
-		mei_cl_unlink(cl);
-		kfree(cl);
+/**
+ * mei_cl_bus_dev_stop - stop the driver
+ *
+ * @cldev: me client device
+ */
+static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
+{
+	if (cldev->is_added)
+		device_release_driver(&cldev->dev);
+}
+
+/**
+ * mei_cl_bus_dev_destroy - destroy me client devices object
+ *
+ * @cldev: me client device
+ */
+static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
+{
+	if (!cldev->is_added)
+		return;
+
+	device_del(&cldev->dev);
+
+	mutex_lock(&cldev->bus->cl_bus_lock);
+	list_del_init(&cldev->bus_list);
+	mutex_unlock(&cldev->bus->cl_bus_lock);
+
+	cldev->is_added = 0;
+	put_device(&cldev->dev);
+}
+
+/**
+ * mei_cl_bus_remove_device - remove a devices form the bus
+ *
+ * @cldev: me client device
+ */
+static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
+{
+	mei_cl_bus_dev_stop(cldev);
+	mei_cl_bus_dev_destroy(cldev);
+}
+
+/**
+ * mei_cl_bus_remove_devices - remove all devices form the bus
+ *
+ * @bus: mei device
+ */
+void mei_cl_bus_remove_devices(struct mei_device *bus)
+{
+	struct mei_cl_device *cldev, *next;
+
+	list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
+		mei_cl_bus_remove_device(cldev);
+}
+
+
+/**
+ * mei_cl_dev_init - allocate and initializes an mei client devices
+ *     based on me client
+ *
+ * @bus: mei device
+ * @me_cl: me client
+ */
+static void mei_cl_dev_init(struct mei_device *bus, struct mei_me_client *me_cl)
+{
+	struct mei_cl_device *cldev;
+
+	dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
+
+	if (me_cl->bus_added)
+		return;
+
+	cldev = mei_cl_dev_alloc(bus, me_cl);
+	if (!cldev)
+		return;
+
+	mutex_lock(&cldev->bus->cl_bus_lock);
+	me_cl->bus_added = true;
+	list_add_tail(&cldev->bus_list, &bus->device_list);
+	mutex_unlock(&cldev->bus->cl_bus_lock);
+
+}
+
+/**
+ * mei_cl_bus_rescan - scan me clients list and add create
+ *    devices for eligible clients
+ *
+ * @bus: mei device
+ */
+void mei_cl_bus_rescan(struct mei_device *bus)
+{
+	struct mei_cl_device *cldev, *n;
+	struct mei_me_client *me_cl;
+
+	down_read(&bus->me_clients_rwsem);
+	list_for_each_entry(me_cl, &bus->me_clients, list)
+		mei_cl_dev_init(bus, me_cl);
+	up_read(&bus->me_clients_rwsem);
+
+	mutex_lock(&bus->cl_bus_lock);
+	list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
+
+		if (!mei_me_cl_is_active(cldev->me_cl)) {
+			mei_cl_bus_remove_device(cldev);
+			continue;
+		}
+
+		if (cldev->is_added)
+			continue;
+
+		if (mei_cl_dev_setup(bus, cldev))
+			mei_cl_bus_dev_add(cldev);
+		else {
+			list_del_init(&cldev->bus_list);
+			put_device(&cldev->dev);
+		}
 	}
-	mutex_unlock(&dev->device_lock);
+	mutex_unlock(&bus->cl_bus_lock);
+
+	dev_dbg(bus->dev, "rescan end");
 }
 
+int __mei_cl_driver_register(struct mei_cl_driver *cldrv, struct module *owner)
+{
+	int err;
+
+	cldrv->driver.name = cldrv->name;
+	cldrv->driver.owner = owner;
+	cldrv->driver.bus = &mei_cl_bus_type;
+
+	err = driver_register(&cldrv->driver);
+	if (err)
+		return err;
+
+	pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
+
+void mei_cl_driver_unregister(struct mei_cl_driver *cldrv)
+{
+	driver_unregister(&cldrv->driver);
+
+	pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
+}
+EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
+
+
 int __init mei_cl_bus_init(void)
 {
 	return bus_register(&mei_cl_bus_type);