File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/uwb/scan.c b/drivers/uwb/scan.c
new file mode 100644
index 0000000..cbb6a5e
--- /dev/null
+++ b/drivers/uwb/scan.c
@@ -0,0 +1,135 @@
+/*
+ * Ultra Wide Band
+ * Scanning management
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ *
+ * FIXME: docs
+ * FIXME: there are issues here on how BEACON and SCAN on USB RCI deal
+ *        with each other. Currently seems that START_BEACON while
+ *        SCAN_ONLY will cancel the scan, so we need to update the
+ *        state here. Clarification request sent by email on
+ *        10/05/2005.
+ *        10/28/2005 No clear answer heard--maybe we'll hack the API
+ *                   so that when we start beaconing, if the HC is
+ *                   scanning in a mode not compatible with beaconing
+ *                   we just fail.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include "uwb-internal.h"
+
+
+/**
+ * Start/stop scanning in a radio controller
+ *
+ * @rc:      UWB Radio Controller
+ * @channel: Channel to scan; encodings in WUSB1.0[Table 5.12]
+ * @type:    Type of scanning to do.
+ * @bpst_offset: value at which to start scanning (if type ==
+ *                UWB_SCAN_ONLY_STARTTIME)
+ * @returns: 0 if ok, < 0 errno code on error
+ *
+ * We put the command on kmalloc'ed memory as some arches cannot do
+ * USB from the stack. The reply event is copied from an stage buffer,
+ * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
+ */
+int uwb_rc_scan(struct uwb_rc *rc,
+		unsigned channel, enum uwb_scan_type type,
+		unsigned bpst_offset)
+{
+	int result;
+	struct uwb_rc_cmd_scan *cmd;
+	struct uwb_rc_evt_confirm reply;
+
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	mutex_lock(&rc->uwb_dev.mutex);
+	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SCAN);
+	cmd->bChannelNumber = channel;
+	cmd->bScanState = type;
+	cmd->wStartTime = cpu_to_le16(bpst_offset);
+	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply.rceb.wEvent = UWB_RC_CMD_SCAN;
+	result = uwb_rc_cmd(rc, "SCAN", &cmd->rccb, sizeof(*cmd),
+			    &reply.rceb, sizeof(reply));
+	if (result < 0)
+		goto error_cmd;
+	if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
+		dev_err(&rc->uwb_dev.dev,
+			"SCAN: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
+		result = -EIO;
+		goto error_cmd;
+	}
+	rc->scanning = channel;
+	rc->scan_type = type;
+error_cmd:
+	mutex_unlock(&rc->uwb_dev.mutex);
+	kfree(cmd);
+error_kzalloc:
+	return result;
+}
+
+/*
+ * Print scanning state
+ */
+static ssize_t uwb_rc_scan_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_rc *rc = uwb_dev->rc;
+	ssize_t result;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+	result = sprintf(buf, "%d %d\n", rc->scanning, rc->scan_type);
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return result;
+}
+
+/*
+ *
+ */
+static ssize_t uwb_rc_scan_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_rc *rc = uwb_dev->rc;
+	unsigned channel;
+	unsigned type;
+	unsigned bpst_offset = 0;
+	ssize_t result = -EINVAL;
+
+	result = sscanf(buf, "%u %u %u\n", &channel, &type, &bpst_offset);
+	if (result >= 2 && type < UWB_SCAN_TOP)
+		result = uwb_rc_scan(rc, channel, type, bpst_offset);
+
+	return result < 0 ? result : size;
+}
+
+/** Radio Control sysfs interface (declaration) */
+DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);