mei: bus: Add device enabling and disabling API

It should be left to the drivers to enable and disable the device on the
MEI bus when e.g getting probed.
For drivers to be able to safely call the enable and disable hooks, the
mei_cl_ops must be set before it's probed and thus this should happen
before registering the device on the MEI bus. Hence the mei_cl_add_device()
prototype change.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 98 insertions, 1 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 6badfa1110e9..834ceeb69cbf 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -153,7 +153,8 @@ static struct mei_cl *mei_bus_find_mei_cl_by_uuid(struct mei_device *dev,
 	return NULL;
 }
 struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
-				  uuid_le uuid, char *name)
+					uuid_le uuid, char *name,
+					struct mei_cl_ops *ops)
 {
 	struct mei_cl_device *device;
 	struct mei_cl *cl;
@@ -168,6 +169,7 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
 		return NULL;
 
 	device->cl = cl;
+	device->ops = ops;
 
 	device->dev.parent = &dev->pdev->dev;
 	device->dev.bus = &mei_cl_bus_type;
@@ -408,6 +410,101 @@ void mei_cl_set_drvdata(struct mei_cl_device *device, void *data)
 }
 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
 
+int mei_cl_enable_device(struct mei_cl_device *device)
+{
+	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);
+
+	cl->state = MEI_FILE_CONNECTING;
+
+	err = mei_cl_connect(cl, NULL);
+	if (err < 0) {
+		mutex_unlock(&dev->device_lock);
+		dev_err(&dev->pdev->dev, "Could not connect to the ME client");
+
+		return err;
+	}
+
+	mutex_unlock(&dev->device_lock);
+
+	if (device->event_cb && !cl->read_cb)
+		mei_cl_read_start(device->cl);
+
+	if (!device->ops || !device->ops->enable)
+		return 0;
+
+	return device->ops->enable(device);
+}
+EXPORT_SYMBOL_GPL(mei_cl_enable_device);
+
+int mei_cl_disable_device(struct mei_cl_device *device)
+{
+	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);
+
+	if (cl->state != MEI_FILE_CONNECTED) {
+		mutex_unlock(&dev->device_lock);
+		dev_err(&dev->pdev->dev, "Already disconnected");
+
+		return 0;
+	}
+
+	cl->state = MEI_FILE_DISCONNECTING;
+
+	err = mei_cl_disconnect(cl);
+	if (err < 0) {
+		mutex_unlock(&dev->device_lock);
+		dev_err(&dev->pdev->dev,
+			"Could not disconnect from the ME client");
+
+		return err;
+	}
+
+	/* Flush queues and remove any pending read */
+	mei_cl_flush_queues(cl);
+
+	if (cl->read_cb) {
+		struct mei_cl_cb *cb = NULL;
+
+		cb = mei_cl_find_read_cb(cl);
+		/* Remove entry from read list */
+		if (cb)
+			list_del(&cb->list);
+
+		cb = cl->read_cb;
+		cl->read_cb = NULL;
+
+		if (cb) {
+			mei_io_cb_free(cb);
+			cb = NULL;
+		}
+	}
+
+	mutex_unlock(&dev->device_lock);
+
+	if (!device->ops || !device->ops->disable)
+		return 0;
+
+	return device->ops->disable(device);
+}
+EXPORT_SYMBOL_GPL(mei_cl_disable_device);
+
 void mei_cl_bus_rx_event(struct mei_cl *cl)
 {
 	struct mei_cl_device *device = cl->device;