mei: add async event notification ioctls

Add ioctl IOCTL_MEI_NOTIFY_SET for enabling and disabling
async event notification.
Add ioctl IOCTL_MEI_NOTIFY_GET for receiving and acking
an event notification.

Signed-off-by: Tomas Winkler <[e-mail]>
Signed-off-by: Alexander Usyskin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ioctl/ioctl-number.txt

···
 'H'	00-7F	linux/hiddev.h		conflict!
 'H'	00-0F	linux/hidraw.h		conflict!
 'H'	01	linux/mei.h		conflict!
+'H'	02	linux/mei.h		conflict!
+'H'	03	linux/mei.h		conflict!
 'H'	00-0F	sound/asound.h		conflict!
 'H'	20-40	sound/asound_fm.h	conflict!
 'H'	80-8F	sound/sfnt_info.h	conflict!

Documentation/misc-devices/mei/mei.txt

···
 IOCTL
 =====
 
-The Intel MEI Driver supports the following IOCTL command:
+The Intel MEI Driver supports the following IOCTL commands:
 	IOCTL_MEI_CONNECT_CLIENT	Connect to firmware Feature (client).
 
 	usage:
···
         max_msg_length (MTU) in client properties describes the maximum
         data that can be sent or received. (e.g. if MTU=2K, can send
         requests up to bytes 2k and received responses up to 2k bytes).
+
+	IOCTL_MEI_NOTIFY_SET: enable or disable event notifications
+
+	Usage:
+		uint32_t enable;
+		ioctl(fd, IOCTL_MEI_NOTIFY_SET, &enable);
+
+	Inputs:
+		uint32_t enable = 1;
+		or
+		uint32_t enable[disable] = 0;
+
+	Error returns:
+		EINVAL	Wrong IOCTL Number
+		ENODEV	Device  is not initialized or the client not connected
+		ENOMEM	Unable to allocate memory to client internal data.
+		EFAULT	Fatal Error (e.g. Unable to access user input data)
+		EOPNOTSUPP if the device doesn't support the feature
+
+	Notes:
+	The client must be connected in order to enable notification events
+
+
+	IOCTL_MEI_NOTIFY_GET : retrieve event
+
+	Usage:
+		uint32_t event;
+		ioctl(fd, IOCTL_MEI_NOTIFY_GET, &event);
+
+	Outputs:
+		1 - if an event is pending
+		0 - if there is no even pending
+
+	Error returns:
+		EINVAL	Wrong IOCTL Number
+		ENODEV	Device is not initialized or the client not connected
+		ENOMEM	Unable to allocate memory to client internal data.
+		EFAULT	Fatal Error (e.g. Unable to access user input data)
+		EOPNOTSUPP if the device doesn't support the feature
+
+	Notes:
+	The client must be connected and event notification has to be enabled
+	in order to receive an event
 
 
 Intel ME Applications

drivers/misc/mei/main.c

···
 }
 
 /**
+ * mei_ioctl_client_notify_request -
+ *     propagate event notification request to client
+ *
+ * @file: pointer to file structure
+ * @request: 0 - disable, 1 - enable
+ *
+ * Return: 0 on success , <0 on error
+ */
+static int mei_ioctl_client_notify_request(struct file *file, u32 request)
+{
+	struct mei_cl *cl = file->private_data;
+
+	return mei_cl_notify_request(cl, file, request);
+}
+
+/**
+ * mei_ioctl_client_notify_get -  wait for notification request
+ *
+ * @file: pointer to file structure
+ * @notify_get: 0 - disable, 1 - enable
+ *
+ * Return: 0 on success , <0 on error
+ */
+static int mei_ioctl_client_notify_get(struct file *file, u32 *notify_get)
+{
+	struct mei_cl *cl = file->private_data;
+	bool notify_ev;
+	bool block = (file->f_flags & O_NONBLOCK) == 0;
+	int rets;
+
+	rets = mei_cl_notify_get(cl, block, &notify_ev);
+	if (rets)
+		return rets;
+
+	*notify_get = notify_ev ? 1 : 0;
+	return 0;
+}
+
+/**
  * mei_ioctl - the IOCTL function
  *
  * @file: pointer to file structure
···
 	struct mei_device *dev;
 	struct mei_cl *cl = file->private_data;
 	struct mei_connect_client_data connect_data;
+	u32 notify_get, notify_req;
 	int rets;
 
 
···
 			goto out;
 		}
 
+		break;
+
+	case IOCTL_MEI_NOTIFY_SET:
+		dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
+		if (copy_from_user(&notify_req,
+				   (char __user *)data, sizeof(notify_req))) {
+			dev_dbg(dev->dev, "failed to copy data from userland\n");
+			rets = -EFAULT;
+			goto out;
+		}
+		rets = mei_ioctl_client_notify_request(file, notify_req);
+		break;
+
+	case IOCTL_MEI_NOTIFY_GET:
+		dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
+		rets = mei_ioctl_client_notify_get(file, &notify_get);
+		if (rets)
+			goto out;
+
+		dev_dbg(dev->dev, "copy connect data to user\n");
+		if (copy_to_user((char __user *)data,
+				&notify_get, sizeof(notify_get))) {
+			dev_dbg(dev->dev, "failed to copy data to userland\n");
+			rets = -EFAULT;
+			goto out;
+
+		}
 		break;
 
 	default:

include/uapi/linux/mei.h

···
 	};
 };
 
+/**
+ * DOC: set and unset event notification for a connected client
+ *
+ * The IOCTL argument is 1 for enabling event notification and 0 for
+ * disabling the service
+ * Return:  -EOPNOTSUPP if the devices doesn't support the feature
+ */
+#define IOCTL_MEI_NOTIFY_SET _IOW('H', 0x02, __u32)
+
+/**
+ * DOC: retrieve notification
+ *
+ * The IOCTL output argument is 1 if an event was is pending and 0 otherwise
+ * the ioctl has to be called in order to acknowledge pending event
+ *
+ * Return:  -EOPNOTSUPP if the devices doesn't support the feature
+ */
+#define IOCTL_MEI_NOTIFY_GET _IOR('H', 0x03, __u32)
+
 #endif /* _LINUX_MEI_H  */