uwb: add basic radio manager

The UWB radio manager coordinates the use of the radio between the
PALs that may be using it.  PALs request use of the radio with
uwb_radio_start() and the radio manager will start beaconing if its
not already doing so.  When the last PAL has called uwb_radio_stop()
beaconing will be stopped.

In the future, the radio manager will have a more sophisticated channel
selection algorithm, probably following the Channel Selection Policy
from the WiMedia Alliance when it is finalized.  For now, channel 9
(BG1, TFC1) is selected.

The user may override the channel selected by the radio manager and may
force the radio to stop beaconing.

The WUSB Host Controller PAL makes use of this and there are two new
debug PAL commands that can be used for testing.
Signed-off-by: David Vrabel <david.vrabel@csr.com>

Documentation/ABI/testing/sysfs-class-uwb_rc

@@ -32,14 +32,16 @@ Contact:        linux-usb@vger.kernel.org
 Description:
                 Write:
 
-                <channel> [<bpst offset>]
+                <channel>
 
-                to start beaconing on a specific channel, or stop
-                beaconing if <channel> is -1.  Valid channels depends
-                on the radio controller's supported band groups.
+                to force a specific channel to be used when beaconing,
+                or, if <channel> is -1, to prohibit beaconing.  If
+                <channel> is 0, then the default channel selection
+                algorithm will be used.  Valid channels depends on the
+                radio controller's supported band groups.
 
-                <bpst offset> may be used to try and join a specific
-                beacon group if more than one was found during a scan.
+                Reading returns the currently active channel, or -1 if
+                the radio controller is not beaconing.
 
 What:           /sys/class/uwb_rc/uwbN/scan
 Date:           July 2008

Documentation/usb/wusb-cbaf

@@ -80,12 +80,6 @@ case $1 in
     start)
         for dev in ${2:-$hdevs}
           do
-          uwb_rc=$(readlink -f $dev/uwb_rc)
-          if cat $uwb_rc/beacon | grep -q -- "-1"
-              then
-              echo 13 0 > $uwb_rc/beacon
-              echo I: started beaconing on ch 13 on $(basename $uwb_rc) >&2
-          fi
           echo $host_CHID > $dev/wusb_chid
           echo I: started host $(basename $dev) >&2
         done
@@ -95,9 +89,6 @@ case $1 in
           do
           echo 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > $dev/wusb_chid
           echo I: stopped host $(basename $dev) >&2
-          uwb_rc=$(readlink -f $dev/uwb_rc)
-          echo -1 | cat > $uwb_rc/beacon
-          echo I: stopped beaconing on $(basename $uwb_rc) >&2
         done
         ;;
     set-chid)

drivers/usb/host/hwa-hc.c

@@ -221,7 +221,6 @@ static void hwahc_op_stop(struct usb_hcd *usb_hcd)
 
 	d_fnstart(4, dev, "(hwahc %p)\n", hwahc);
 	mutex_lock(&wusbhc->mutex);
-	wusbhc_stop(wusbhc);
 	wusb_cluster_id_put(wusbhc->cluster_id);
 	mutex_unlock(&wusbhc->mutex);
 	d_fnend(4, dev, "(hwahc %p) = %d\n", hwahc, result);

drivers/usb/host/whci/hcd.c

@@ -91,8 +91,6 @@ static void whc_stop(struct usb_hcd *usb_hcd)
 
 	mutex_lock(&wusbhc->mutex);
 
-	wusbhc_stop(wusbhc);
-
 	/* stop HC */
 	le_writel(0, whc->base + WUSBINTR);
 	whc_write_wusbcmd(whc, WUSBCMD_RUN, 0);

drivers/usb/wusbcore/devconnect.c

@@ -1124,8 +1124,7 @@ void wusbhc_devconnect_destroy(struct wusbhc *wusbhc)
  * FIXME: This also enables the keep alives but this is not necessary
  * until there are connected and authenticated devices.
  */
-int wusbhc_devconnect_start(struct wusbhc *wusbhc,
-			    const struct wusb_ckhdid *chid)
+int wusbhc_devconnect_start(struct wusbhc *wusbhc)
 {
 	struct device *dev = wusbhc->dev;
 	struct wuie_host_info *hi;
@@ -1138,7 +1137,7 @@ int wusbhc_devconnect_start(struct wusbhc *wusbhc,
 	hi->hdr.bLength       = sizeof(*hi);
 	hi->hdr.bIEIdentifier = WUIE_ID_HOST_INFO;
 	hi->attributes        = cpu_to_le16((wusbhc->rsv->stream << 3) | WUIE_HI_CAP_ALL);
-	hi->CHID              = *chid;
+	hi->CHID              = wusbhc->chid;
 	result = wusbhc_mmcie_set(wusbhc, 0, 0, &hi->hdr);
 	if (result < 0) {
 		dev_err(dev, "Cannot add Host Info MMCIE: %d\n", result);

drivers/usb/wusbcore/mmc.c

@@ -162,12 +162,11 @@ EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
 /*
  * wusbhc_start - start transmitting MMCs and accepting connections
  * @wusbhc: the HC to start
- * @chid: the CHID to use for this host
  *
  * Establishes a cluster reservation, enables device connections, and
  * starts MMCs with appropriate DNTS parameters.
  */
-int wusbhc_start(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
+int wusbhc_start(struct wusbhc *wusbhc)
 {
 	int result;
 	struct device *dev = wusbhc->dev;
@@ -181,7 +180,7 @@ int wusbhc_start(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
 		goto error_rsv_establish;
 	}
 
-	result = wusbhc_devconnect_start(wusbhc, chid);
+	result = wusbhc_devconnect_start(wusbhc);
 	if (result < 0) {
 		dev_err(dev, "error enabling device connections: %d\n", result);
 		goto error_devconnect_start;
@@ -218,34 +217,6 @@ int wusbhc_start(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
 	return result;
 }
 
-/*
- * Disconnect all from the WUSB Channel
- *
- * Send a Host Disconnect IE in the MMC, wait, don't send it any more
- */
-static int __wusbhc_host_disconnect_ie(struct wusbhc *wusbhc)
-{
-	int result = -ENOMEM;
-	struct wuie_host_disconnect *host_disconnect_ie;
-	might_sleep();
-	host_disconnect_ie = kmalloc(sizeof(*host_disconnect_ie), GFP_KERNEL);
-	if (host_disconnect_ie == NULL)
-		goto error_alloc;
-	host_disconnect_ie->hdr.bLength       = sizeof(*host_disconnect_ie);
-	host_disconnect_ie->hdr.bIEIdentifier = WUIE_ID_HOST_DISCONNECT;
-	result = wusbhc_mmcie_set(wusbhc, 0, 0, &host_disconnect_ie->hdr);
-	if (result < 0)
-		goto error_mmcie_set;
-
-	/* WUSB1.0[8.5.3.1 & 7.5.2] */
-	msleep(100);
-	wusbhc_mmcie_rm(wusbhc, &host_disconnect_ie->hdr);
-error_mmcie_set:
-	kfree(host_disconnect_ie);
-error_alloc:
-	return result;
-}
-
 /*
  * wusbhc_stop - stop transmitting MMCs
  * @wusbhc: the HC to stop
@@ -264,29 +235,6 @@ void wusbhc_stop(struct wusbhc *wusbhc)
 }
 EXPORT_SYMBOL_GPL(wusbhc_stop);
 
-/*
- * Change the CHID in a WUSB Channel
- *
- * If it is just a new CHID, send a Host Disconnect IE and then change
- * the CHID IE.
- */
-static int __wusbhc_chid_change(struct wusbhc *wusbhc,
-				const struct wusb_ckhdid *chid)
-{
-	int result = -ENOSYS;
-	struct device *dev = wusbhc->dev;
-	dev_err(dev, "%s() not implemented yet\n", __func__);
-	return result;
-
-	BUG_ON(wusbhc->wuie_host_info == NULL);
-	__wusbhc_host_disconnect_ie(wusbhc);
-	wusbhc->wuie_host_info->CHID = *chid;
-	result = wusbhc_mmcie_set(wusbhc, 0, 0, &wusbhc->wuie_host_info->hdr);
-	if (result < 0)
-		dev_err(dev, "Can't update Host Info WUSB IE: %d\n", result);
-	return result;
-}
-
 /*
  * Set/reset/update a new CHID
  *
@@ -302,16 +250,19 @@ int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
 		chid = NULL;
 
 	mutex_lock(&wusbhc->mutex);
-	if (wusbhc->active) {
-		if (chid)
-			result = __wusbhc_chid_change(wusbhc, chid);
-		else
-			wusbhc_stop(wusbhc);
-	} else {
-		if (chid)
-			wusbhc_start(wusbhc, chid);
+	if (chid) {
+		if (wusbhc->active) {
+			mutex_unlock(&wusbhc->mutex);
+			return -EBUSY;
+		}
+		wusbhc->chid = *chid;
 	}
 	mutex_unlock(&wusbhc->mutex);
+
+	if (chid)
+		result = uwb_radio_start(&wusbhc->pal);
+	else
+		uwb_radio_stop(&wusbhc->pal);
 	return result;
 }
 EXPORT_SYMBOL_GPL(wusbhc_chid_set);

drivers/usb/wusbcore/pal.c

@@ -18,6 +18,16 @@
  */
 #include "wusbhc.h"
 
+static void wusbhc_channel_changed(struct uwb_pal *pal, int channel)
+{
+	struct wusbhc *wusbhc = container_of(pal, struct wusbhc, pal);
+
+	if (channel < 0)
+		wusbhc_stop(wusbhc);
+	else
+		wusbhc_start(wusbhc);
+}
+
 /**
  * wusbhc_pal_register - register the WUSB HC as a UWB PAL
  * @wusbhc: the WUSB HC
@@ -28,8 +38,10 @@ int wusbhc_pal_register(struct wusbhc *wusbhc)
 
 	wusbhc->pal.name   = "wusbhc";
 	wusbhc->pal.device = wusbhc->usb_hcd.self.controller;
+	wusbhc->pal.rc     = wusbhc->uwb_rc;
+	wusbhc->pal.channel_changed = wusbhc_channel_changed;
 
-	return uwb_pal_register(wusbhc->uwb_rc, &wusbhc->pal);
+	return uwb_pal_register(&wusbhc->pal);
 }
 
 /**
@@ -38,5 +50,5 @@ int wusbhc_pal_register(struct wusbhc *wusbhc)
  */
 void wusbhc_pal_unregister(struct wusbhc *wusbhc)
 {
-	uwb_pal_unregister(wusbhc->uwb_rc, &wusbhc->pal);
+	uwb_pal_unregister(&wusbhc->pal);
 }

drivers/usb/wusbcore/wusbhc.h

@@ -252,7 +252,8 @@ struct wusbhc {
 	struct uwb_pal pal;
 
 	unsigned trust_timeout;			/* in jiffies */
-	struct wuie_host_info *wuie_host_info;	/* Includes CHID */
+	struct wusb_ckhdid chid;
+	struct wuie_host_info *wuie_host_info;
 
 	struct mutex mutex;			/* locks everything else */
 	u16 cluster_id;				/* Wireless USB Cluster ID */
@@ -376,15 +377,14 @@ static inline void wusbhc_put(struct wusbhc *wusbhc)
 	usb_put_hcd(&wusbhc->usb_hcd);
 }
 
-int wusbhc_start(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid);
+int wusbhc_start(struct wusbhc *wusbhc);
 void wusbhc_stop(struct wusbhc *wusbhc);
 extern int wusbhc_chid_set(struct wusbhc *, const struct wusb_ckhdid *);
 
 /* Device connect handling */
 extern int wusbhc_devconnect_create(struct wusbhc *);
 extern void wusbhc_devconnect_destroy(struct wusbhc *);
-extern int wusbhc_devconnect_start(struct wusbhc *wusbhc,
-				   const struct wusb_ckhdid *chid);
+extern int wusbhc_devconnect_start(struct wusbhc *wusbhc);
 extern void wusbhc_devconnect_stop(struct wusbhc *wusbhc);
 extern void wusbhc_handle_dn(struct wusbhc *, u8 srcaddr,
 			     struct wusb_dn_hdr *dn_hdr, size_t size);

drivers/uwb/Makefile

@@ -18,6 +18,7 @@ uwb-objs :=		\
 	lc-rc.o		\
 	neh.o		\
 	pal.o		\
+	radio.o		\
 	reset.o		\
 	rsv.o		\
 	scan.o		\

drivers/uwb/beacon.c

@@ -119,7 +119,6 @@ int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset)
 	int result;
 	struct device *dev = &rc->uwb_dev.dev;
 
-	mutex_lock(&rc->uwb_dev.mutex);
 	if (channel < 0)
 		channel = -1;
 	if (channel == -1)
@@ -128,7 +127,7 @@ int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset)
 		/* channel >= 0...dah */
 		result = uwb_rc_start_beacon(rc, bpst_offset, channel);
 		if (result < 0)
-			goto out_up;
+			return result;
 		if (le16_to_cpu(rc->ies->wIELength) > 0) {
 			result = uwb_rc_set_ie(rc, rc->ies);
 			if (result < 0) {
@@ -137,19 +136,14 @@ int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset)
 				result = uwb_rc_stop_beacon(rc);
 				channel = -1;
 				bpst_offset = 0;
-			} else
-				result = 0;
+			}
 		}
 	}
 
-	if (result < 0)
-		goto out_up;
-	rc->beaconing = channel;
-
-	uwb_notify(rc, NULL, uwb_bg_joined(rc) ? UWB_NOTIF_BG_JOIN : UWB_NOTIF_BG_LEAVE);
-
-out_up:
-	mutex_unlock(&rc->uwb_dev.mutex);
+	if (result >= 0) {
+		rc->beaconing = channel;
+		uwb_notify(rc, NULL, uwb_bg_joined(rc) ? UWB_NOTIF_BG_JOIN : UWB_NOTIF_BG_LEAVE);
+	}
 	return result;
 }
 
@@ -618,9 +612,6 @@ static ssize_t uwb_rc_beacon_show(struct device *dev,
 
 /*
  * Start beaconing on the specified channel, or stop beaconing.
- *
- * The BPST offset of when to start searching for a beacon group to
- * join may be specified.
  */
 static ssize_t uwb_rc_beacon_store(struct device *dev,
 				   struct device_attribute *attr,
@@ -629,12 +620,11 @@ static ssize_t uwb_rc_beacon_store(struct device *dev,
 	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 	struct uwb_rc *rc = uwb_dev->rc;
 	int channel;
-	unsigned bpst_offset = 0;
 	ssize_t result = -EINVAL;
 
-	result = sscanf(buf, "%d %u\n", &channel, &bpst_offset);
+	result = sscanf(buf, "%d", &channel);
 	if (result >= 1)
-		result = uwb_rc_beacon(rc, channel, bpst_offset);
+		result = uwb_radio_force_channel(rc, channel);
 
 	return result < 0 ? result : size;
 }

drivers/uwb/drp.c

@@ -37,14 +37,13 @@
  *
  * A DRP Availability IE is appended.
  *
- * rc->uwb_dev.mutex is held
+ * rc->rsvs_mutex is held
  *
  * FIXME We currently ignore the returned value indicating the remaining space
  * in beacon. This could be used to deny reservation requests earlier if
  * determined that they would cause the beacon space to be exceeded.
  */
-static
-int uwb_rc_gen_send_drp_ie(struct uwb_rc *rc)
+int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
 {
 	int result;
 	struct device *dev = &rc->uwb_dev.dev;
@@ -102,25 +101,6 @@ int uwb_rc_gen_send_drp_ie(struct uwb_rc *rc)
 	kfree(cmd);
 error:
 	return result;
-
-}
-/**
- * Send all DRP IEs associated with this host
- *
- * @returns:    >= 0 number of bytes still available in the beacon
- *              < 0 errno code on error.
- *
- * As per the protocol we obtain the host controller device lock to access
- * bandwidth structures.
- */
-int uwb_rc_send_all_drp_ie(struct uwb_rc *rc)
-{
-	int result;
-
-	mutex_lock(&rc->uwb_dev.mutex);
-	result = uwb_rc_gen_send_drp_ie(rc);
-	mutex_unlock(&rc->uwb_dev.mutex);
-	return result;
 }
 
 void uwb_drp_handle_timeout(struct uwb_rsv *rsv)

drivers/uwb/lc-rc.c

@@ -189,9 +189,9 @@ static int uwb_rc_setup(struct uwb_rc *rc)
 	int result;
 	struct device *dev = &rc->uwb_dev.dev;
 
-	result = uwb_rc_reset(rc);
+	result = uwb_radio_setup(rc);
 	if (result < 0) {
-		dev_err(dev, "cannot reset UWB radio: %d\n", result);
+		dev_err(dev, "cannot setup UWB radio: %d\n", result);
 		goto error;
 	}
 	result = uwb_rc_mac_addr_setup(rc);
@@ -311,12 +311,7 @@ void uwb_rc_rm(struct uwb_rc *rc)
 
 	uwb_dbg_del_rc(rc);
 	uwb_rsv_remove_all(rc);
-	uwb_rc_ie_rm(rc, UWB_IDENTIFICATION_IE);
-	if (rc->beaconing >= 0)
-		uwb_rc_beacon(rc, -1, 0);
-	if (rc->scan_type != UWB_SCAN_DISABLED)
-		uwb_rc_scan(rc, rc->scanning, UWB_SCAN_DISABLED, 0);
-	uwb_rc_reset(rc);
+	uwb_radio_shutdown(rc);
 
 	rc->stop(rc);
 

drivers/uwb/pal.c

@@ -32,13 +32,13 @@ EXPORT_SYMBOL_GPL(uwb_pal_init);
 
 /**
  * uwb_pal_register - register a UWB PAL
- * @rc: the radio controller the PAL will be using
  * @pal: the PAL
  *
  * The PAL must be initialized with uwb_pal_init().
  */
-int uwb_pal_register(struct uwb_rc *rc, struct uwb_pal *pal)
+int uwb_pal_register(struct uwb_pal *pal)
 {
+	struct uwb_rc *rc = pal->rc;
 	int ret;
 
 	if (pal->device) {
@@ -54,9 +54,9 @@ int uwb_pal_register(struct uwb_rc *rc, struct uwb_pal *pal)
 		}
 	}
 
-	spin_lock(&rc->pal_lock);
+	mutex_lock(&rc->uwb_dev.mutex);
 	list_add(&pal->node, &rc->pals);
-	spin_unlock(&rc->pal_lock);
+	mutex_unlock(&rc->uwb_dev.mutex);
 
 	return 0;
 }
@@ -64,14 +64,17 @@ EXPORT_SYMBOL_GPL(uwb_pal_register);
 
 /**
  * uwb_pal_register - unregister a UWB PAL
- * @rc: the radio controller the PAL was using
  * @pal: the PAL
  */
-void uwb_pal_unregister(struct uwb_rc *rc, struct uwb_pal *pal)
+void uwb_pal_unregister(struct uwb_pal *pal)
 {
-	spin_lock(&rc->pal_lock);
+	struct uwb_rc *rc = pal->rc;
+
+	uwb_radio_stop(pal);
+
+	mutex_lock(&rc->uwb_dev.mutex);
 	list_del(&pal->node);
-	spin_unlock(&rc->pal_lock);
+	mutex_unlock(&rc->uwb_dev.mutex);
 
 	if (pal->device) {
 		sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
@@ -86,6 +89,5 @@ EXPORT_SYMBOL_GPL(uwb_pal_unregister);
  */
 void uwb_rc_pal_init(struct uwb_rc *rc)
 {
-	spin_lock_init(&rc->pal_lock);
 	INIT_LIST_HEAD(&rc->pals);
 }

drivers/uwb/radio.c

+/*
+ * UWB radio (channel) management.
+ *
+ * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/uwb.h>
+
+#include "uwb-internal.h"
+
+
+static int uwb_radio_select_channel(struct uwb_rc *rc)
+{
+	/*
+	 * Default to channel 9 (BG1, TFC1) unless the user has
+	 * selected a specific channel or there are no active PALs.
+	 */
+	if (rc->active_pals == 0)
+		return -1;
+	if (rc->beaconing_forced)
+		return rc->beaconing_forced;
+	return 9;
+}
+
+
+/*
+ * Notify all active PALs that the channel has changed.
+ */
+static void uwb_radio_channel_changed(struct uwb_rc *rc, int channel)
+{
+	struct uwb_pal *pal;
+
+	list_for_each_entry(pal, &rc->pals, node) {
+		if (pal->channel && channel != pal->channel) {
+			pal->channel = channel;
+			if (pal->channel_changed)
+				pal->channel_changed(pal, pal->channel);
+		}
+	}
+}
+
+/*
+ * Change to a new channel and notify any active PALs of the new
+ * channel.
+ *
+ * When stopping the radio, PALs need to be notified first so they can
+ * terminate any active reservations.
+ */
+static int uwb_radio_change_channel(struct uwb_rc *rc, int channel)
+{
+	int ret = 0;
+
+	if (channel == -1)
+		uwb_radio_channel_changed(rc, channel);
+
+	if (channel != rc->beaconing) {
+		if (rc->beaconing != -1 && channel != -1) {
+			/*
+			 * FIXME: should signal the channel change
+			 * with a Channel Change IE.
+			 */
+			ret = uwb_radio_change_channel(rc, -1);
+			if (ret < 0)
+				return ret;
+		}
+		ret = uwb_rc_beacon(rc, channel, 0);
+	}
+
+	if (channel != -1)
+		uwb_radio_channel_changed(rc, rc->beaconing);
+
+	return ret;
+}
+
+/**
+ * uwb_radio_start - request that the radio be started
+ * @pal: the PAL making the request.
+ *
+ * If the radio is not already active, aa suitable channel is selected
+ * and beacons are started.
+ */
+int uwb_radio_start(struct uwb_pal *pal)
+{
+	struct uwb_rc *rc = pal->rc;
+	int ret = 0;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+
+	if (!pal->channel) {
+		pal->channel = -1;
+		rc->active_pals++;
+		ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
+	}
+
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(uwb_radio_start);
+
+/**
+ * uwb_radio_stop - request tha the radio be stopped.
+ * @pal: the PAL making the request.
+ *
+ * Stops the radio if no other PAL is making use of it.
+ */
+void uwb_radio_stop(struct uwb_pal *pal)
+{
+	struct uwb_rc *rc = pal->rc;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+
+	if (pal->channel) {
+		rc->active_pals--;
+		uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
+		pal->channel = 0;
+	}
+
+	mutex_unlock(&rc->uwb_dev.mutex);
+}
+EXPORT_SYMBOL_GPL(uwb_radio_stop);
+
+/*
+ * uwb_radio_force_channel - force a specific channel to be used
+ * @rc: the radio controller.
+ * @channel: the channel to use; -1 to force the radio to stop; 0 to
+ *   use the default channel selection algorithm.
+ */
+int uwb_radio_force_channel(struct uwb_rc *rc, int channel)
+{
+	int ret = 0;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+
+	rc->beaconing_forced = channel;
+	ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc));
+
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return ret;
+}
+
+/*
+ * uwb_radio_setup - setup the radio manager
+ * @rc: the radio controller.
+ *
+ * The radio controller is reset to ensure it's in a known state
+ * before it's used.
+ */
+int uwb_radio_setup(struct uwb_rc *rc)
+{
+	return uwb_rc_reset(rc);
+}
+
+/*
+ * uwb_radio_reset_state - reset any radio manager state
+ * @rc: the radio controller.
+ *
+ * All internal radio manager state is reset to values corresponding
+ * to a reset radio controller.
+ */
+void uwb_radio_reset_state(struct uwb_rc *rc)
+{
+	struct uwb_pal *pal;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+
+	list_for_each_entry(pal, &rc->pals, node) {
+		if (pal->channel) {
+			pal->channel = -1;
+			if (pal->channel_changed)
+				pal->channel_changed(pal, -1);
+		}
+	}
+
+	rc->beaconing = -1;
+	rc->scanning = -1;
+
+	mutex_unlock(&rc->uwb_dev.mutex);
+}
+
+/*
+ * uwb_radio_shutdown - shutdown the radio manager
+ * @rc: the radio controller.
+ *
+ * The radio controller is reset.
+ */
+void uwb_radio_shutdown(struct uwb_rc *rc)
+{
+	uwb_radio_reset_state(rc);
+	uwb_rc_reset(rc);
+}

drivers/uwb/reset.c

@@ -365,11 +365,7 @@ void uwb_rc_pre_reset(struct uwb_rc *rc)
 	rc->stop(rc);
 	uwbd_flush(rc);
 
-	mutex_lock(&rc->uwb_dev.mutex);
-	rc->beaconing = -1;
-	rc->scanning = -1;
-	mutex_unlock(&rc->uwb_dev.mutex);
-
+	uwb_radio_reset_state(rc);
 	uwb_rsv_remove_all(rc);
 }
 EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);

drivers/uwb/rsv.c

@@ -555,14 +555,14 @@ static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
 	 * deny the request.
 	 */
 	rsv->state = UWB_RSV_STATE_T_DENIED;
-	spin_lock(&rc->pal_lock);
+	mutex_lock(&rc->uwb_dev.mutex);
 	list_for_each_entry(pal, &rc->pals, node) {
 		if (pal->new_rsv)
 			pal->new_rsv(pal, rsv);
 		if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
 			break;
 	}
-	spin_unlock(&rc->pal_lock);
+	mutex_unlock(&rc->uwb_dev.mutex);
 
 	list_add_tail(&rsv->rc_node, &rc->reservations);
 	state = rsv->state;

drivers/uwb/uwb-debug.c

@@ -192,7 +192,7 @@ static ssize_t command_write(struct file *file, const char __user *buf,
 {
 	struct uwb_rc *rc = file->private_data;
 	struct uwb_dbg_cmd cmd;
-	int ret;
+	int ret = 0;
 
 	if (len != sizeof(struct uwb_dbg_cmd))
 		return -EINVAL;
@@ -213,6 +213,12 @@ static ssize_t command_write(struct file *file, const char __user *buf,
 	case UWB_DBG_CMD_IE_RM:
 		ret = cmd_ie_rm(rc, &cmd.ie_rm);
 		break;
+	case UWB_DBG_CMD_RADIO_START:
+		ret = uwb_radio_start(&rc->dbg->pal);
+		break;
+	case UWB_DBG_CMD_RADIO_STOP:
+		uwb_radio_stop(&rc->dbg->pal);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -306,6 +312,17 @@ static struct file_operations drp_avail_fops = {
 	.owner   = THIS_MODULE,
 };
 
+static void uwb_dbg_channel_changed(struct uwb_pal *pal, int channel)
+{
+	struct uwb_dbg *dbg = container_of(pal, struct uwb_dbg, pal);
+	struct device *dev = &pal->rc->uwb_dev.dev;
+
+	if (channel > 0)
+		dev_info(dev, "debug: channel %d started\n", channel);
+	else
+		dev_info(dev, "debug: channel stopped\n");
+}
+
 static void uwb_dbg_new_rsv(struct uwb_pal *pal, struct uwb_rsv *rsv)
 {
 	struct uwb_dbg *dbg = container_of(pal, struct uwb_dbg, pal);
@@ -329,8 +346,11 @@ void uwb_dbg_add_rc(struct uwb_rc *rc)
 	INIT_LIST_HEAD(&rc->dbg->rsvs);
 
 	uwb_pal_init(&rc->dbg->pal);
+	rc->dbg->pal.rc = rc;
+	rc->dbg->pal.channel_changed = uwb_dbg_channel_changed;
 	rc->dbg->pal.new_rsv = uwb_dbg_new_rsv;
-	uwb_pal_register(rc, &rc->dbg->pal);
+	uwb_pal_register(&rc->dbg->pal);
+
 	if (root_dir) {
 		rc->dbg->root_d = debugfs_create_dir(dev_name(&rc->uwb_dev.dev),
 						     root_dir);
@@ -364,7 +384,7 @@ void uwb_dbg_del_rc(struct uwb_rc *rc)
 		uwb_rsv_terminate(rsv);
 	}
 
-	uwb_pal_unregister(rc, &rc->dbg->pal);
+	uwb_pal_unregister(&rc->dbg->pal);
 
 	if (root_dir) {
 		debugfs_remove(rc->dbg->drp_avail_f);

drivers/uwb/uwb-internal.h

@@ -238,6 +238,11 @@ struct uwb_dev *uwb_dev_get_by_devaddr(struct uwb_rc *rc,
 struct uwb_dev *uwb_dev_get_by_macaddr(struct uwb_rc *rc,
 				       const struct uwb_mac_addr *macaddr);
 
+int uwb_radio_setup(struct uwb_rc *rc);
+void uwb_radio_reset_state(struct uwb_rc *rc);
+void uwb_radio_shutdown(struct uwb_rc *rc);
+int uwb_radio_force_channel(struct uwb_rc *rc, int channel);
+
 /* -- UWB Sysfs representation */
 extern struct class uwb_rc_class;
 extern struct device_attribute dev_attr_mac_address;

drivers/uwb/wlp/wlp-lc.c

@@ -543,7 +543,8 @@ int wlp_setup(struct wlp *wlp, struct uwb_rc *rc)
 	uwb_notifs_register(rc, &wlp->uwb_notifs_handler);
 
 	uwb_pal_init(&wlp->pal);
-	result = uwb_pal_register(rc, &wlp->pal);
+	wlp->pal.rc = rc;
+	result = uwb_pal_register(&wlp->pal);
 	if (result < 0)
 		uwb_notifs_deregister(wlp->rc, &wlp->uwb_notifs_handler);
 
@@ -557,7 +558,7 @@ void wlp_remove(struct wlp *wlp)
 	struct device *dev = &wlp->rc->uwb_dev.dev;
 	d_fnstart(6, dev, "wlp %p\n", wlp);
 	wlp_neighbors_release(wlp);
-	uwb_pal_unregister(wlp->rc, &wlp->pal);
+	uwb_pal_unregister(&wlp->pal);
 	uwb_notifs_deregister(wlp->rc, &wlp->uwb_notifs_handler);
 	wlp_eda_release(&wlp->eda);
 	mutex_lock(&wlp->mutex);

include/linux/uwb.h

@@ -355,6 +355,7 @@ struct uwb_rc {
 	u8 ctx_roll;
 
 	int beaconing;			/* Beaconing state [channel number] */
+	int beaconing_forced;
 	int scanning;
 	enum uwb_scan_type scan_type:3;
 	unsigned ready:1;
@@ -373,8 +374,8 @@ struct uwb_rc {
 	struct uwb_rc_cmd_set_ie *ies;
 	size_t ies_capacity;
 
-	spinlock_t pal_lock;
 	struct list_head pals;
+	int active_pals;
 
 	struct uwb_dbg *dbg;
 };
@@ -382,11 +383,17 @@ struct uwb_rc {
 
 /**
  * struct uwb_pal - a UWB PAL
- * @name:    descriptive name for this PAL (wushc, wlp, etc.).
+ * @name:    descriptive name for this PAL (wusbhc, wlp, etc.).
  * @device:  a device for the PAL.  Used to link the PAL and the radio
  *           controller in sysfs.
+ * @rc:      the radio controller the PAL uses.
+ * @channel_changed: called when the channel used by the radio changes.
+ *           A channel of -1 means the channel has been stopped.
  * @new_rsv: called when a peer requests a reservation (may be NULL if
  *           the PAL cannot accept reservation requests).
+ * @channel: channel being used by the PAL; 0 if the PAL isn't using
+ *           the radio; -1 if the PAL wishes to use the radio but
+ *           cannot.
  *
  * A Protocol Adaptation Layer (PAL) is a user of the WiMedia UWB
  * radio platform (e.g., WUSB, WLP or Bluetooth UWB AMP).
@@ -405,12 +412,20 @@ struct uwb_pal {
 	struct list_head node;
 	const char *name;
 	struct device *device;
+	struct uwb_rc *rc;
+
+	void (*channel_changed)(struct uwb_pal *pal, int channel);
 	void (*new_rsv)(struct uwb_pal *pal, struct uwb_rsv *rsv);
+
+	int channel;
 };
 
 void uwb_pal_init(struct uwb_pal *pal);
-int uwb_pal_register(struct uwb_rc *rc, struct uwb_pal *pal);
-void uwb_pal_unregister(struct uwb_rc *rc, struct uwb_pal *pal);
+int uwb_pal_register(struct uwb_pal *pal);
+void uwb_pal_unregister(struct uwb_pal *pal);
+
+int uwb_radio_start(struct uwb_pal *pal);
+void uwb_radio_stop(struct uwb_pal *pal);
 
 /*
  * General public API

include/linux/uwb/debug-cmd.h

@@ -34,6 +34,8 @@ enum uwb_dbg_cmd_type {
 	UWB_DBG_CMD_RSV_TERMINATE = 2,
 	UWB_DBG_CMD_IE_ADD = 3,
 	UWB_DBG_CMD_IE_RM = 4,
+	UWB_DBG_CMD_RADIO_START = 5,
+	UWB_DBG_CMD_RADIO_STOP = 6,
 };
 
 struct uwb_dbg_cmd_rsv_establish {