uwb: add the UWB stack (radio controller interface)

Add the UWB radio controller interface (URCI) support.
Signed-off-by: NDavid Vrabel <david.vrabel@csr.com>

drivers/uwb/est.c

+/*
+ * Ultra Wide Band Radio Control
+ * Event Size Tables 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
+ *
+ * Infrastructure, code and data tables for guessing the size of
+ * events received on the notification endpoints of UWB radio
+ * controllers.
+ *
+ * You define a table of events and for each, its size and how to get
+ * the extra size.
+ *
+ * ENTRY POINTS:
+ *
+ * uwb_est_{init/destroy}(): To initialize/release the EST subsystem.
+ *
+ * uwb_est_[u]register(): To un/register event size tables
+ *   uwb_est_grow()
+ *
+ * uwb_est_find_size(): Get the size of an event
+ *   uwb_est_get_size()
+ */
+#include <linux/spinlock.h>
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+#include "uwb-internal.h"
+
+
+struct uwb_est {
+	u16 type_event_high;
+	u16 vendor, product;
+	u8 entries;
+	const struct uwb_est_entry *entry;
+};
+
+
+static struct uwb_est *uwb_est;
+static u8 uwb_est_size;
+static u8 uwb_est_used;
+static DEFINE_RWLOCK(uwb_est_lock);
+
+/**
+ * WUSB Standard Event Size Table, HWA-RC interface
+ *
+ * Sizes for events and notifications type 0 (general), high nibble 0.
+ */
+static
+struct uwb_est_entry uwb_est_00_00xx[] = {
+	[UWB_RC_EVT_IE_RCV] = {
+		.size = sizeof(struct uwb_rc_evt_ie_rcv),
+		.offset = 1 + offsetof(struct uwb_rc_evt_ie_rcv, wIELength),
+	},
+	[UWB_RC_EVT_BEACON] = {
+		.size = sizeof(struct uwb_rc_evt_beacon),
+		.offset = 1 + offsetof(struct uwb_rc_evt_beacon, wBeaconInfoLength),
+	},
+	[UWB_RC_EVT_BEACON_SIZE] = {
+		.size = sizeof(struct uwb_rc_evt_beacon_size),
+	},
+	[UWB_RC_EVT_BPOIE_CHANGE] = {
+		.size = sizeof(struct uwb_rc_evt_bpoie_change),
+		.offset = 1 + offsetof(struct uwb_rc_evt_bpoie_change,
+				       wBPOIELength),
+	},
+	[UWB_RC_EVT_BP_SLOT_CHANGE] = {
+		.size = sizeof(struct uwb_rc_evt_bp_slot_change),
+	},
+	[UWB_RC_EVT_BP_SWITCH_IE_RCV] = {
+		.size = sizeof(struct uwb_rc_evt_bp_switch_ie_rcv),
+		.offset = 1 + offsetof(struct uwb_rc_evt_bp_switch_ie_rcv, wIELength),
+	},
+	[UWB_RC_EVT_DEV_ADDR_CONFLICT] = {
+		.size = sizeof(struct uwb_rc_evt_dev_addr_conflict),
+	},
+	[UWB_RC_EVT_DRP_AVAIL] = {
+		.size = sizeof(struct uwb_rc_evt_drp_avail)
+	},
+	[UWB_RC_EVT_DRP] = {
+		.size = sizeof(struct uwb_rc_evt_drp),
+		.offset = 1 + offsetof(struct uwb_rc_evt_drp, ie_length),
+	},
+	[UWB_RC_EVT_BP_SWITCH_STATUS] = {
+		.size = sizeof(struct uwb_rc_evt_bp_switch_status),
+	},
+	[UWB_RC_EVT_CMD_FRAME_RCV] = {
+		.size = sizeof(struct uwb_rc_evt_cmd_frame_rcv),
+		.offset = 1 + offsetof(struct uwb_rc_evt_cmd_frame_rcv, dataLength),
+	},
+	[UWB_RC_EVT_CHANNEL_CHANGE_IE_RCV] = {
+		.size = sizeof(struct uwb_rc_evt_channel_change_ie_rcv),
+		.offset = 1 + offsetof(struct uwb_rc_evt_channel_change_ie_rcv, wIELength),
+	},
+	[UWB_RC_CMD_CHANNEL_CHANGE] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_DEV_ADDR_MGMT] = {
+		.size = sizeof(struct uwb_rc_evt_dev_addr_mgmt) },
+	[UWB_RC_CMD_GET_IE] = {
+		.size = sizeof(struct uwb_rc_evt_get_ie),
+		.offset = 1 + offsetof(struct uwb_rc_evt_get_ie, wIELength),
+	},
+	[UWB_RC_CMD_RESET] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SCAN] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SET_BEACON_FILTER] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SET_DRP_IE] = {
+		.size = sizeof(struct uwb_rc_evt_set_drp_ie),
+	},
+	[UWB_RC_CMD_SET_IE] = {
+		.size = sizeof(struct uwb_rc_evt_set_ie),
+	},
+	[UWB_RC_CMD_SET_NOTIFICATION_FILTER] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SET_TX_POWER] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SLEEP] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_START_BEACON] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_STOP_BEACON] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_BP_MERGE] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SEND_COMMAND_FRAME] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+	[UWB_RC_CMD_SET_ASIE_NOTIF] = {
+		.size = sizeof(struct uwb_rc_evt_confirm),
+	},
+};
+
+static
+struct uwb_est_entry uwb_est_01_00xx[] = {
+	[UWB_RC_DAA_ENERGY_DETECTED] = {
+		.size = sizeof(struct uwb_rc_evt_daa_energy_detected),
+	},
+	[UWB_RC_SET_DAA_ENERGY_MASK] = {
+		.size = sizeof(struct uwb_rc_evt_set_daa_energy_mask),
+	},
+	[UWB_RC_SET_NOTIFICATION_FILTER_EX] = {
+		.size = sizeof(struct uwb_rc_evt_set_notification_filter_ex),
+	},
+};
+
+/**
+ * Initialize the EST subsystem
+ *
+ * Register the standard tables also.
+ *
+ * FIXME: tag init
+ */
+int uwb_est_create(void)
+{
+	int result;
+
+	uwb_est_size = 2;
+	uwb_est_used = 0;
+	uwb_est = kzalloc(uwb_est_size * sizeof(uwb_est[0]), GFP_KERNEL);
+	if (uwb_est == NULL)
+		return -ENOMEM;
+
+	result = uwb_est_register(UWB_RC_CET_GENERAL, 0, 0xffff, 0xffff,
+				  uwb_est_00_00xx, ARRAY_SIZE(uwb_est_00_00xx));
+	if (result < 0)
+		goto out;
+	result = uwb_est_register(UWB_RC_CET_EX_TYPE_1, 0, 0xffff, 0xffff,
+				  uwb_est_01_00xx, ARRAY_SIZE(uwb_est_01_00xx));
+out:
+	return result;
+}
+
+
+/** Clean it up */
+void uwb_est_destroy(void)
+{
+	kfree(uwb_est);
+	uwb_est = NULL;
+	uwb_est_size = uwb_est_used = 0;
+}
+
+
+/**
+ * Double the capacity of the EST table
+ *
+ * @returns 0 if ok, < 0 errno no error.
+ */
+static
+int uwb_est_grow(void)
+{
+	size_t actual_size = uwb_est_size * sizeof(uwb_est[0]);
+	void *new = kmalloc(2 * actual_size, GFP_ATOMIC);
+	if (new == NULL)
+		return -ENOMEM;
+	memcpy(new, uwb_est, actual_size);
+	memset(new + actual_size, 0, actual_size);
+	kfree(uwb_est);
+	uwb_est = new;
+	uwb_est_size *= 2;
+	return 0;
+}
+
+
+/**
+ * Register an event size table
+ *
+ * Makes room for it if the table is full, and then inserts  it in the
+ * right position (entries are sorted by type, event_high, vendor and
+ * then product).
+ *
+ * @vendor:  vendor code for matching against the device (0x0000 and
+ *           0xffff mean any); use 0x0000 to force all to match without
+ *           checking possible vendor specific ones, 0xfffff to match
+ *           after checking vendor specific ones.
+ *
+ * @product: product code from that vendor; same matching rules, use
+ *           0x0000 for not allowing vendor specific matches, 0xffff
+ *           for allowing.
+ *
+ * This arragement just makes the tables sort differenty. Because the
+ * table is sorted by growing type-event_high-vendor-product, a zero
+ * vendor will match before than a 0x456a vendor, that will match
+ * before a 0xfffff vendor.
+ *
+ * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
+ */
+/* FIXME: add bus type to vendor/product code */
+int uwb_est_register(u8 type, u8 event_high, u16 vendor, u16 product,
+		     const struct uwb_est_entry *entry, size_t entries)
+{
+	unsigned long flags;
+	unsigned itr;
+	u16 type_event_high;
+	int result = 0;
+
+	write_lock_irqsave(&uwb_est_lock, flags);
+	if (uwb_est_used == uwb_est_size) {
+		result = uwb_est_grow();
+		if (result < 0)
+			goto out;
+	}
+	/* Find the right spot to insert it in */
+	type_event_high = type << 8 | event_high;
+	for (itr = 0; itr < uwb_est_used; itr++)
+		if (uwb_est[itr].type_event_high < type
+		    && uwb_est[itr].vendor < vendor
+		    && uwb_est[itr].product < product)
+			break;
+
+	/* Shift others to make room for the new one? */
+	if (itr < uwb_est_used)
+		memmove(&uwb_est[itr+1], &uwb_est[itr], uwb_est_used - itr);
+	uwb_est[itr].type_event_high = type << 8 | event_high;
+	uwb_est[itr].vendor = vendor;
+	uwb_est[itr].product = product;
+	uwb_est[itr].entry = entry;
+	uwb_est[itr].entries = entries;
+	uwb_est_used++;
+out:
+	write_unlock_irqrestore(&uwb_est_lock, flags);
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_est_register);
+
+
+/**
+ * Unregister an event size table
+ *
+ * This just removes the specified entry and moves the ones after it
+ * to fill in the gap. This is needed to keep the list sorted; no
+ * reallocation is done to reduce the size of the table.
+ *
+ * We unregister by all the data we used to register instead of by
+ * pointer to the @entry array because we might have used the same
+ * table for a bunch of IDs (for example).
+ *
+ * @returns 0 if ok, < 0 errno on error (-ENOENT if not found).
+ */
+int uwb_est_unregister(u8 type, u8 event_high, u16 vendor, u16 product,
+		       const struct uwb_est_entry *entry, size_t entries)
+{
+	unsigned long flags;
+	unsigned itr;
+	struct uwb_est est_cmp = {
+		.type_event_high = type << 8 | event_high,
+		.vendor = vendor,
+		.product = product,
+		.entry = entry,
+		.entries = entries
+	};
+	write_lock_irqsave(&uwb_est_lock, flags);
+	for (itr = 0; itr < uwb_est_used; itr++)
+		if (!memcmp(&uwb_est[itr], &est_cmp, sizeof(est_cmp)))
+			goto found;
+	write_unlock_irqrestore(&uwb_est_lock, flags);
+	return -ENOENT;
+
+found:
+	if (itr < uwb_est_used - 1)	/* Not last one? move ones above */
+		memmove(&uwb_est[itr], &uwb_est[itr+1], uwb_est_used - itr - 1);
+	uwb_est_used--;
+	write_unlock_irqrestore(&uwb_est_lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uwb_est_unregister);
+
+
+/**
+ * Get the size of an event from a table
+ *
+ * @rceb: pointer to the buffer with the event
+ * @rceb_size: size of the area pointed to by @rceb in bytes.
+ * @returns: > 0      Size of the event
+ *	     -ENOSPC  An area big enough was not provided to look
+ *		      ahead into the event's guts and guess the size.
+ *	     -EINVAL  Unknown event code (wEvent).
+ *
+ * This will look at the received RCEB and guess what is the total
+ * size. For variable sized events, it will look further ahead into
+ * their length field to see how much data should be read.
+ *
+ * Note this size is *not* final--the neh (Notification/Event Handle)
+ * might specificy an extra size to add.
+ */
+static
+ssize_t uwb_est_get_size(struct uwb_rc *uwb_rc, struct uwb_est *est,
+			 u8 event_low, const struct uwb_rceb *rceb,
+			 size_t rceb_size)
+{
+	unsigned offset;
+	ssize_t size;
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	const struct uwb_est_entry *entry;
+
+	size = -ENOENT;
+	if (event_low >= est->entries) {	/* in range? */
+		if (printk_ratelimit())
+			dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
+				"event %u out of range\n",
+				est, est->type_event_high, est->vendor,
+				est->product, est->entries,
+				event_low);
+		goto out;
+	}
+	size = -ENOENT;
+	entry = &est->entry[event_low];
+	if (entry->size == 0 && entry->offset == 0) {	/* unknown? */
+		if (printk_ratelimit())
+			dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
+				"event %u unknown\n",
+				est, est->type_event_high, est->vendor,
+				est->product, est->entries, event_low);
+		goto out;
+	}
+	offset = entry->offset;	/* extra fries with that? */
+	if (offset == 0)
+		size = entry->size;
+	else {
+		/* Ops, got an extra size field at 'offset'--read it */
+		const void *ptr = rceb;
+		size_t type_size = 0;
+		offset--;
+		size = -ENOSPC;			/* enough data for more? */
+		switch (entry->type) {
+		case UWB_EST_16:  type_size = sizeof(__le16); break;
+		case UWB_EST_8:   type_size = sizeof(u8);     break;
+		default: 	 BUG();
+		}
+		if (offset + type_size >= rceb_size) {
+			if (printk_ratelimit())
+				dev_err(dev, "EST %p 0x%04x/%04x/%04x[%u]: "
+					"not enough data to read extra size\n",
+					est, est->type_event_high, est->vendor,
+					est->product, est->entries);
+			goto out;
+		}
+		size = entry->size;
+		ptr += offset;
+		switch (entry->type) {
+		case UWB_EST_16:  size += le16_to_cpu(*(__le16 *)ptr); break;
+		case UWB_EST_8:   size += *(u8 *)ptr;                  break;
+		default: 	 BUG();
+		}
+	}
+out:
+	return size;
+}
+
+
+/**
+ * Guesses the size of a WA event
+ *
+ * @rceb: pointer to the buffer with the event
+ * @rceb_size: size of the area pointed to by @rceb in bytes.
+ * @returns: > 0      Size of the event
+ *	     -ENOSPC  An area big enough was not provided to look
+ *		      ahead into the event's guts and guess the size.
+ *	     -EINVAL  Unknown event code (wEvent).
+ *
+ * This will look at the received RCEB and guess what is the total
+ * size by checking all the tables registered with
+ * uwb_est_register(). For variable sized events, it will look further
+ * ahead into their length field to see how much data should be read.
+ *
+ * Note this size is *not* final--the neh (Notification/Event Handle)
+ * might specificy an extra size to add or replace.
+ */
+ssize_t uwb_est_find_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
+			  size_t rceb_size)
+{
+	/* FIXME: add vendor/product data */
+	ssize_t size;
+	struct device *dev = &rc->uwb_dev.dev;
+	unsigned long flags;
+	unsigned itr;
+	u16 type_event_high, event;
+	u8 *ptr = (u8 *) rceb;
+
+	read_lock_irqsave(&uwb_est_lock, flags);
+	d_printf(2, dev, "Size query for event 0x%02x/%04x/%02x,"
+		 " buffer size %ld\n",
+		 (unsigned) rceb->bEventType,
+		 (unsigned) le16_to_cpu(rceb->wEvent),
+		 (unsigned) rceb->bEventContext,
+		 (long) rceb_size);
+	size = -ENOSPC;
+	if (rceb_size < sizeof(*rceb))
+		goto out;
+	event = le16_to_cpu(rceb->wEvent);
+	type_event_high = rceb->bEventType << 8 | (event & 0xff00) >> 8;
+	for (itr = 0; itr < uwb_est_used; itr++) {
+		d_printf(3, dev, "Checking EST 0x%04x/%04x/%04x\n",
+			uwb_est[itr].type_event_high, uwb_est[itr].vendor,
+			uwb_est[itr].product);
+		if (uwb_est[itr].type_event_high != type_event_high)
+			continue;
+		size = uwb_est_get_size(rc, &uwb_est[itr],
+					event & 0x00ff, rceb, rceb_size);
+		/* try more tables that might handle the same type */
+		if (size != -ENOENT)
+			goto out;
+	}
+	/* FIXME: downgrade to _dbg() */
+	if (printk_ratelimit())
+		dev_err(dev, "event 0x%02x/%04x/%02x: no handlers available; "
+		"RCEB %02x %02x %02x %02x\n",
+			(unsigned) rceb->bEventType,
+			(unsigned) le16_to_cpu(rceb->wEvent),
+			(unsigned) rceb->bEventContext,
+			ptr[0], ptr[1], ptr[2], ptr[3]);
+	size = -ENOENT;
+out:
+	read_unlock_irqrestore(&uwb_est_lock, flags);
+	return size;
+}
+EXPORT_SYMBOL_GPL(uwb_est_find_size);

drivers/uwb/neh.c

+/*
+ * WUSB Wire Adapter: Radio Control Interface (WUSB[8])
+ * Notification and Event Handling
+ *
+ * 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.
+ *
+ *
+ * The RC interface of the Host Wire Adapter (USB dongle) or WHCI PCI
+ * card delivers a stream of notifications and events to the
+ * notification end event endpoint or area. This code takes care of
+ * getting a buffer with that data, breaking it up in separate
+ * notifications and events and then deliver those.
+ *
+ * Events are answers to commands and they carry a context ID that
+ * associates them to the command. Notifications are that,
+ * notifications, they come out of the blue and have a context ID of
+ * zero. Think of the context ID kind of like a handler. The
+ * uwb_rc_neh_* code deals with managing context IDs.
+ *
+ * This is why you require a handle to operate on a UWB host. When you
+ * open a handle a context ID is assigned to you.
+ *
+ * So, as it is done is:
+ *
+ * 1. Add an event handler [uwb_rc_neh_add()] (assigns a ctx id)
+ * 2. Issue command [rc->cmd(rc, ...)]
+ * 3. Arm the timeout timer [uwb_rc_neh_arm()]
+ * 4, Release the reference to the neh [uwb_rc_neh_put()]
+ * 5. Wait for the callback
+ * 6. Command result (RCEB) is passed to the callback
+ *
+ * If (2) fails, you should remove the handle [uwb_rc_neh_rm()]
+ * instead of arming the timer.
+ *
+ * Handles are for using in *serialized* code, single thread.
+ *
+ * When the notification/event comes, the IRQ handler/endpoint
+ * callback passes the data read to uwb_rc_neh_grok() which will break
+ * it up in a discrete series of events, look up who is listening for
+ * them and execute the pertinent callbacks.
+ *
+ * If the reader detects an error while reading the data stream, call
+ * uwb_rc_neh_error().
+ *
+ * CONSTRAINTS/ASSUMPTIONS:
+ *
+ * - Most notifications/events are small (less thank .5k), copying
+ *   around is ok.
+ *
+ * - Notifications/events are ALWAYS smaller than PAGE_SIZE
+ *
+ * - Notifications/events always come in a single piece (ie: a buffer
+ *   will always contain entire notifications/events).
+ *
+ * - we cannot know in advance how long each event is (because they
+ *   lack a length field in their header--smart move by the standards
+ *   body, btw). So we need a facility to get the event size given the
+ *   header. This is what the EST code does (notif/Event Size
+ *   Tables), check nest.c--as well, you can associate the size to
+ *   the handle [w/ neh->extra_size()].
+ *
+ * - Most notifications/events are fixed size; only a few are variable
+ *   size (NEST takes care of that).
+ *
+ * - Listeners of events expect them, so they usually provide a
+ *   buffer, as they know the size. Listeners to notifications don't,
+ *   so we allocate their buffers dynamically.
+ */
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/err.h>
+
+#include "uwb-internal.h"
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+
+/*
+ * UWB Radio Controller Notification/Event Handle
+ *
+ * Represents an entity waiting for an event coming from the UWB Radio
+ * Controller with a given context id (context) and type (evt_type and
+ * evt). On reception of the notification/event, the callback (cb) is
+ * called with the event.
+ *
+ * If the timer expires before the event is received, the callback is
+ * called with -ETIMEDOUT as the event size.
+ */
+struct uwb_rc_neh {
+	struct kref kref;
+
+	struct uwb_rc *rc;
+	u8 evt_type;
+	__le16 evt;
+	u8 context;
+	uwb_rc_cmd_cb_f cb;
+	void *arg;
+
+	struct timer_list timer;
+	struct list_head list_node;
+};
+
+static void uwb_rc_neh_timer(unsigned long arg);
+
+static void uwb_rc_neh_release(struct kref *kref)
+{
+	struct uwb_rc_neh *neh = container_of(kref, struct uwb_rc_neh, kref);
+
+	kfree(neh);
+}
+
+static void uwb_rc_neh_get(struct uwb_rc_neh *neh)
+{
+	kref_get(&neh->kref);
+}
+
+/**
+ * uwb_rc_neh_put - release reference to a neh
+ * @neh: the neh
+ */
+void uwb_rc_neh_put(struct uwb_rc_neh *neh)
+{
+	kref_put(&neh->kref, uwb_rc_neh_release);
+}
+
+
+/**
+ * Assigns @neh a context id from @rc's pool
+ *
+ * @rc:	    UWB Radio Controller descriptor; @rc->neh_lock taken
+ * @neh:    Notification/Event Handle
+ * @returns 0 if context id was assigned ok; < 0 errno on error (if
+ *	    all the context IDs are taken).
+ *
+ * (assumes @wa is locked).
+ *
+ * NOTE: WUSB spec reserves context ids 0x00 for notifications and
+ *	 0xff is invalid, so they must not be used. Initialization
+ *	 fills up those two in the bitmap so they are not allocated.
+ *
+ * We spread the allocation around to reduce the posiblity of two
+ * consecutive opened @neh's getting the same context ID assigned (to
+ * avoid surprises with late events that timed out long time ago). So
+ * first we search from where @rc->ctx_roll is, if not found, we
+ * search from zero.
+ */
+static
+int __uwb_rc_ctx_get(struct uwb_rc *rc, struct uwb_rc_neh *neh)
+{
+	int result;
+	result = find_next_zero_bit(rc->ctx_bm, UWB_RC_CTX_MAX,
+				    rc->ctx_roll++);
+	if (result < UWB_RC_CTX_MAX)
+		goto found;
+	result = find_first_zero_bit(rc->ctx_bm, UWB_RC_CTX_MAX);
+	if (result < UWB_RC_CTX_MAX)
+		goto found;
+	return -ENFILE;
+found:
+	set_bit(result, rc->ctx_bm);
+	neh->context = result;
+	return 0;
+}
+
+
+/** Releases @neh's context ID back to @rc (@rc->neh_lock is locked). */
+static
+void __uwb_rc_ctx_put(struct uwb_rc *rc, struct uwb_rc_neh *neh)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	if (neh->context == 0)
+		return;
+	if (test_bit(neh->context, rc->ctx_bm) == 0) {
+		dev_err(dev, "context %u not set in bitmap\n",
+			neh->context);
+		WARN_ON(1);
+	}
+	clear_bit(neh->context, rc->ctx_bm);
+	neh->context = 0;
+}
+
+/**
+ * uwb_rc_neh_add - add a neh for a radio controller command
+ * @rc:             the radio controller
+ * @cmd:            the radio controller command
+ * @expected_type:  the type of the expected response event
+ * @expected_event: the expected event ID
+ * @cb:             callback for when the event is received
+ * @arg:            argument for the callback
+ *
+ * Creates a neh and adds it to the list of those waiting for an
+ * event.  A context ID will be assigned to the command.
+ */
+struct uwb_rc_neh *uwb_rc_neh_add(struct uwb_rc *rc, struct uwb_rccb *cmd,
+				  u8 expected_type, u16 expected_event,
+				  uwb_rc_cmd_cb_f cb, void *arg)
+{
+	int result;
+	unsigned long flags;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_neh *neh;
+
+	neh = kzalloc(sizeof(*neh), GFP_KERNEL);
+	if (neh == NULL) {
+		result = -ENOMEM;
+		goto error_kzalloc;
+	}
+
+	kref_init(&neh->kref);
+	INIT_LIST_HEAD(&neh->list_node);
+	init_timer(&neh->timer);
+	neh->timer.function = uwb_rc_neh_timer;
+	neh->timer.data     = (unsigned long)neh;
+
+	neh->rc = rc;
+	neh->evt_type = expected_type;
+	neh->evt = cpu_to_le16(expected_event);
+	neh->cb = cb;
+	neh->arg = arg;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	result = __uwb_rc_ctx_get(rc, neh);
+	if (result >= 0) {
+		cmd->bCommandContext = neh->context;
+		list_add_tail(&neh->list_node, &rc->neh_list);
+		uwb_rc_neh_get(neh);
+	}
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+	if (result < 0)
+		goto error_ctx_get;
+
+	return neh;
+
+error_ctx_get:
+	kfree(neh);
+error_kzalloc:
+	dev_err(dev, "cannot open handle to radio controller: %d\n", result);
+	return ERR_PTR(result);
+}
+
+static void __uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
+{
+	del_timer(&neh->timer);
+	__uwb_rc_ctx_put(rc, neh);
+	list_del(&neh->list_node);
+}
+
+/**
+ * uwb_rc_neh_rm - remove a neh.
+ * @rc:  the radio controller
+ * @neh: the neh to remove
+ *
+ * Remove an active neh immediately instead of waiting for the event
+ * (or a time out).
+ */
+void uwb_rc_neh_rm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	__uwb_rc_neh_rm(rc, neh);
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+
+	uwb_rc_neh_put(neh);
+}
+
+/**
+ * uwb_rc_neh_arm - arm an event handler timeout timer
+ *
+ * @rc:     UWB Radio Controller
+ * @neh:    Notification/event handler for @rc
+ *
+ * The timer is only armed if the neh is active.
+ */
+void uwb_rc_neh_arm(struct uwb_rc *rc, struct uwb_rc_neh *neh)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	if (neh->context)
+		mod_timer(&neh->timer,
+			  jiffies + msecs_to_jiffies(UWB_RC_CMD_TIMEOUT_MS));
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+}
+
+static void uwb_rc_neh_cb(struct uwb_rc_neh *neh, struct uwb_rceb *rceb, size_t size)
+{
+	(*neh->cb)(neh->rc, neh->arg, rceb, size);
+	uwb_rc_neh_put(neh);
+}
+
+static bool uwb_rc_neh_match(struct uwb_rc_neh *neh, const struct uwb_rceb *rceb)
+{
+	return neh->evt_type == rceb->bEventType
+		&& neh->evt == rceb->wEvent
+		&& neh->context == rceb->bEventContext;
+}
+
+/**
+ * Find the handle waiting for a RC Radio Control Event
+ *
+ * @rc:         UWB Radio Controller
+ * @rceb:       Pointer to the RCEB buffer
+ * @event_size: Pointer to the size of the RCEB buffer. Might be
+ *              adjusted to take into account the @neh->extra_size
+ *              settings.
+ *
+ * If the listener has no buffer (NULL buffer), one is allocated for
+ * the right size (the amount of data received). @neh->ptr will point
+ * to the event payload, which always starts with a 'struct
+ * uwb_rceb'. kfree() it when done.
+ */
+static
+struct uwb_rc_neh *uwb_rc_neh_lookup(struct uwb_rc *rc,
+				     const struct uwb_rceb *rceb)
+{
+	struct uwb_rc_neh *neh = NULL, *h;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+
+	list_for_each_entry(h, &rc->neh_list, list_node) {
+		if (uwb_rc_neh_match(h, rceb)) {
+			neh = h;
+			break;
+		}
+	}
+
+	if (neh)
+		__uwb_rc_neh_rm(rc, neh);
+
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+
+	return neh;
+}
+
+
+/**
+ * Process notifications coming from the radio control interface
+ *
+ * @rc:    UWB Radio Control Interface descriptor
+ * @neh:   Notification/Event Handler @neh->ptr points to
+ *         @uwb_evt->buffer.
+ *
+ * This function is called by the event/notif handling subsystem when
+ * notifications arrive (hwarc_probe() arms a notification/event handle
+ * that calls back this function for every received notification; this
+ * function then will rearm itself).
+ *
+ * Notification data buffers are dynamically allocated by the NEH
+ * handling code in neh.c [uwb_rc_neh_lookup()]. What is actually
+ * allocated is space to contain the notification data.
+ *
+ * Buffers are prefixed with a Radio Control Event Block (RCEB) as
+ * defined by the WUSB Wired-Adapter Radio Control interface. We
+ * just use it for the notification code.
+ *
+ * On each case statement we just transcode endianess of the different
+ * fields. We declare a pointer to a RCI definition of an event, and
+ * then to a UWB definition of the same event (which are the same,
+ * remember). Event if we use different pointers
+ */
+static
+void uwb_rc_notif(struct uwb_rc *rc, struct uwb_rceb *rceb, ssize_t size)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_event *uwb_evt;
+
+	if (size == -ESHUTDOWN)
+		return;
+	if (size < 0) {
+		dev_err(dev, "ignoring event with error code %zu\n",
+			size);
+		return;
+	}
+
+	uwb_evt = kzalloc(sizeof(*uwb_evt), GFP_ATOMIC);
+	if (unlikely(uwb_evt == NULL)) {
+		dev_err(dev, "no memory to queue event 0x%02x/%04x/%02x\n",
+			rceb->bEventType, le16_to_cpu(rceb->wEvent),
+			rceb->bEventContext);
+		return;
+	}
+	uwb_evt->rc = __uwb_rc_get(rc);	/* will be put by uwbd's uwbd_event_handle() */
+	uwb_evt->ts_jiffies = jiffies;
+	uwb_evt->type = UWB_EVT_TYPE_NOTIF;
+	uwb_evt->notif.size = size;
+	uwb_evt->notif.rceb = rceb;
+
+	switch (le16_to_cpu(rceb->wEvent)) {
+		/* Trap some vendor specific events
+		 *
+		 * FIXME: move this to handling in ptc-est, where we
+		 * register a NULL event handler for these two guys
+		 * using the Intel IDs.
+		 */
+	case 0x0103:
+		dev_info(dev, "FIXME: DEVICE ADD\n");
+		return;
+	case 0x0104:
+		dev_info(dev, "FIXME: DEVICE RM\n");
+		return;
+	default:
+		break;
+	}
+
+	uwbd_event_queue(uwb_evt);
+}
+
+static void uwb_rc_neh_grok_event(struct uwb_rc *rc, struct uwb_rceb *rceb, size_t size)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_neh *neh;
+	struct uwb_rceb *notif;
+
+	if (rceb->bEventContext == 0) {
+		notif = kmalloc(size, GFP_ATOMIC);
+		if (notif) {
+			memcpy(notif, rceb, size);
+			uwb_rc_notif(rc, notif, size);
+		} else
+			dev_err(dev, "event 0x%02x/%04x/%02x (%zu bytes): no memory\n",
+				rceb->bEventType, le16_to_cpu(rceb->wEvent),
+				rceb->bEventContext, size);
+	} else {
+		neh = uwb_rc_neh_lookup(rc, rceb);
+		if (neh)
+			uwb_rc_neh_cb(neh, rceb, size);
+		else if (printk_ratelimit())
+			dev_warn(dev, "event 0x%02x/%04x/%02x (%zu bytes): nobody cared\n",
+				 rceb->bEventType, le16_to_cpu(rceb->wEvent),
+				 rceb->bEventContext, size);
+	}
+}
+
+/**
+ * Given a buffer with one or more UWB RC events/notifications, break
+ * them up and dispatch them.
+ *
+ * @rc:	      UWB Radio Controller
+ * @buf:      Buffer with the stream of notifications/events
+ * @buf_size: Amount of data in the buffer
+ *
+ * Note each notification/event starts always with a 'struct
+ * uwb_rceb', so the minimum size if 4 bytes.
+ *
+ * The device may pass us events formatted differently than expected.
+ * These are first filtered, potentially creating a new event in a new
+ * memory location. If a new event is created by the filter it is also
+ * freed here.
+ *
+ * For each notif/event, tries to guess the size looking at the EST
+ * tables, then looks for a neh that is waiting for that event and if
+ * found, copies the payload to the neh's buffer and calls it back. If
+ * not, the data is ignored.
+ *
+ * Note that if we can't find a size description in the EST tables, we
+ * still might find a size in the 'neh' handle in uwb_rc_neh_lookup().
+ *
+ * Assumptions:
+ *
+ *   @rc->neh_lock is NOT taken
+ *
+ * We keep track of various sizes here:
+ * size:      contains the size of the buffer that is processed for the
+ *            incoming event. this buffer may contain events that are not
+ *            formatted as WHCI.
+ * real_size: the actual space taken by this event in the buffer.
+ *            We need to keep track of the real size of an event to be able to
+ *            advance the buffer correctly.
+ * event_size: the size of the event as expected by the core layer
+ *            [OR] the size of the event after filtering. if the filtering
+ *            created a new event in a new memory location then this is
+ *            effectively the size of a new event buffer
+ */
+void uwb_rc_neh_grok(struct uwb_rc *rc, void *buf, size_t buf_size)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	void *itr;
+	struct uwb_rceb *rceb;
+	size_t size, real_size, event_size;
+	int needtofree;
+
+	d_fnstart(3, dev, "(rc %p buf %p %zu buf_size)\n", rc, buf, buf_size);
+	d_printf(2, dev, "groking event block: %zu bytes\n", buf_size);
+	itr = buf;
+	size = buf_size;
+	while (size > 0) {
+		if (size < sizeof(*rceb)) {
+			dev_err(dev, "not enough data in event buffer to "
+				"process incoming events (%zu left, minimum is "
+				"%zu)\n", size, sizeof(*rceb));
+			break;
+		}
+
+		rceb = itr;
+		if (rc->filter_event) {
+			needtofree = rc->filter_event(rc, &rceb, size,
+						      &real_size, &event_size);
+			if (needtofree < 0 && needtofree != -ENOANO) {
+				dev_err(dev, "BUG: Unable to filter event "
+					"(0x%02x/%04x/%02x) from "
+					"device. \n", rceb->bEventType,
+					le16_to_cpu(rceb->wEvent),
+					rceb->bEventContext);
+				break;
+			}
+		} else
+			needtofree = -ENOANO;
+		/* do real processing if there was no filtering or the
+		 * filtering didn't act */
+		if (needtofree == -ENOANO) {
+			ssize_t ret = uwb_est_find_size(rc, rceb, size);
+			if (ret < 0)
+				break;
+			if (ret > size) {
+				dev_err(dev, "BUG: hw sent incomplete event "
+					"0x%02x/%04x/%02x (%zd bytes), only got "
+					"%zu bytes. We don't handle that.\n",
+					rceb->bEventType, le16_to_cpu(rceb->wEvent),
+					rceb->bEventContext, ret, size);
+				break;
+			}
+			real_size = event_size = ret;
+		}
+		uwb_rc_neh_grok_event(rc, rceb, event_size);
+
+		if (needtofree == 1)
+			kfree(rceb);
+
+		itr += real_size;
+		size -= real_size;
+		d_printf(2, dev, "consumed %zd bytes, %zu left\n",
+			 event_size, size);
+	}
+	d_fnend(3, dev, "(rc %p buf %p %zu buf_size) = void\n", rc, buf, buf_size);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_neh_grok);
+
+
+/**
+ * The entity that reads from the device notification/event channel has
+ * detected an error.
+ *
+ * @rc:    UWB Radio Controller
+ * @error: Errno error code
+ *
+ */
+void uwb_rc_neh_error(struct uwb_rc *rc, int error)
+{
+	struct uwb_rc_neh *neh, *next;
+	unsigned long flags;
+
+	BUG_ON(error >= 0);
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	list_for_each_entry_safe(neh, next, &rc->neh_list, list_node) {
+		__uwb_rc_neh_rm(rc, neh);
+		uwb_rc_neh_cb(neh, NULL, error);
+	}
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_neh_error);
+
+
+static void uwb_rc_neh_timer(unsigned long arg)
+{
+	struct uwb_rc_neh *neh = (struct uwb_rc_neh *)arg;
+	struct uwb_rc *rc = neh->rc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	__uwb_rc_neh_rm(rc, neh);
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+
+	uwb_rc_neh_cb(neh, NULL, -ETIMEDOUT);
+}
+
+/** Initializes the @rc's neh subsystem
+ */
+void uwb_rc_neh_create(struct uwb_rc *rc)
+{
+	spin_lock_init(&rc->neh_lock);
+	INIT_LIST_HEAD(&rc->neh_list);
+	set_bit(0, rc->ctx_bm);		/* 0 is reserved (see [WUSB] table 8-65) */
+	set_bit(0xff, rc->ctx_bm);	/* and 0xff is invalid */
+	rc->ctx_roll = 1;
+}
+
+
+/** Release's the @rc's neh subsystem */
+void uwb_rc_neh_destroy(struct uwb_rc *rc)
+{
+	unsigned long flags;
+	struct uwb_rc_neh *neh, *next;
+
+	spin_lock_irqsave(&rc->neh_lock, flags);
+	list_for_each_entry_safe(neh, next, &rc->neh_list, list_node) {
+		__uwb_rc_neh_rm(rc, neh);
+		uwb_rc_neh_put(neh);
+	}
+	spin_unlock_irqrestore(&rc->neh_lock, flags);
+}

drivers/uwb/reset.c

+/*
+ * Ultra Wide Band
+ * UWB basic command support and radio reset
+ *
+ * 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
+ *
+ *  - Now we are serializing (using the uwb_dev->mutex) the command
+ *    execution; it should be parallelized as much as possible some
+ *    day.
+ */
+#include <linux/kernel.h>
+#include <linux/err.h>
+
+#include "uwb-internal.h"
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+
+/**
+ * Command result codes (WUSB1.0[T8-69])
+ */
+static
+const char *__strerror[] = {
+	"success",
+	"failure",
+	"hardware failure",
+	"no more slots",
+	"beacon is too large",
+	"invalid parameter",
+	"unsupported power level",
+	"time out (wa) or invalid ie data (whci)",
+	"beacon size exceeded",
+	"cancelled",
+	"invalid state",
+	"invalid size",
+	"ack not recieved",
+	"no more asie notification",
+};
+
+
+/** Return a string matching the given error code */
+const char *uwb_rc_strerror(unsigned code)
+{
+	if (code == 255)
+		return "time out";
+	if (code >= ARRAY_SIZE(__strerror))
+		return "unknown error";
+	return __strerror[code];
+}
+
+int uwb_rc_cmd_async(struct uwb_rc *rc, const char *cmd_name,
+		     struct uwb_rccb *cmd, size_t cmd_size,
+		     u8 expected_type, u16 expected_event,
+		     uwb_rc_cmd_cb_f cb, void *arg)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_neh *neh;
+	int needtofree = 0;
+	int result;
+
+	uwb_dev_lock(&rc->uwb_dev);	/* Protect against rc->priv being removed */
+	if (rc->priv == NULL) {
+		uwb_dev_unlock(&rc->uwb_dev);
+		return -ESHUTDOWN;
+	}
+
+	if (rc->filter_cmd) {
+		needtofree = rc->filter_cmd(rc, &cmd, &cmd_size);
+		if (needtofree < 0 && needtofree != -ENOANO) {
+			dev_err(dev, "%s: filter error: %d\n",
+				cmd_name, needtofree);
+			uwb_dev_unlock(&rc->uwb_dev);
+			return needtofree;
+		}
+	}
+
+	neh = uwb_rc_neh_add(rc, cmd, expected_type, expected_event, cb, arg);
+	if (IS_ERR(neh)) {
+		result = PTR_ERR(neh);
+		goto out;
+	}
+
+	result = rc->cmd(rc, cmd, cmd_size);
+	uwb_dev_unlock(&rc->uwb_dev);
+	if (result < 0)
+		uwb_rc_neh_rm(rc, neh);
+	else
+		uwb_rc_neh_arm(rc, neh);
+	uwb_rc_neh_put(neh);
+out:
+	if (needtofree == 1)
+		kfree(cmd);
+	return result < 0 ? result : 0;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_cmd_async);
+
+struct uwb_rc_cmd_done_params {
+	struct completion completion;
+	struct uwb_rceb *reply;
+	ssize_t reply_size;
+};
+
+static void uwb_rc_cmd_done(struct uwb_rc *rc, void *arg,
+			    struct uwb_rceb *reply, ssize_t reply_size)
+{
+	struct uwb_rc_cmd_done_params *p = (struct uwb_rc_cmd_done_params *)arg;
+
+	if (reply_size > 0) {
+		if (p->reply)
+			reply_size = min(p->reply_size, reply_size);
+		else
+			p->reply = kmalloc(reply_size, GFP_ATOMIC);
+
+		if (p->reply)
+			memcpy(p->reply, reply, reply_size);
+		else
+			reply_size = -ENOMEM;
+	}
+	p->reply_size = reply_size;
+	complete(&p->completion);
+}
+
+
+/**
+ * Generic function for issuing commands to the Radio Control Interface
+ *
+ * @rc:       UWB Radio Control descriptor
+ * @cmd_name: Name of the command being issued (for error messages)
+ * @cmd:      Pointer to rccb structure containing the command;
+ *            normally you embed this structure as the first member of
+ *            the full command structure.
+ * @cmd_size: Size of the whole command buffer pointed to by @cmd.
+ * @reply:    Pointer to where to store the reply
+ * @reply_size: @reply's size
+ * @expected_type: Expected type in the return event
+ * @expected_event: Expected event code in the return event
+ * @preply:   Here a pointer to where the event data is received will
+ *            be stored. Once done with the data, free with kfree().
+ *
+ * This function is generic; it works for commands that return a fixed
+ * and known size or for commands that return a variable amount of data.
+ *
+ * If a buffer is provided, that is used, although it could be chopped
+ * to the maximum size of the buffer. If the buffer is NULL, then one
+ * be allocated in *preply with the whole contents of the reply.
+ *
+ * @rc needs to be referenced
+ */
+static
+ssize_t __uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
+		     struct uwb_rccb *cmd, size_t cmd_size,
+		     struct uwb_rceb *reply, size_t reply_size,
+		     u8 expected_type, u16 expected_event,
+		     struct uwb_rceb **preply)
+{
+	ssize_t result = 0;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_cmd_done_params params;
+
+	init_completion(&params.completion);
+	params.reply = reply;
+	params.reply_size = reply_size;
+
+	result = uwb_rc_cmd_async(rc, cmd_name, cmd, cmd_size,
+				  expected_type, expected_event,
+				  uwb_rc_cmd_done, &params);
+	if (result)
+		return result;
+
+	wait_for_completion(&params.completion);
+
+	if (preply)
+		*preply = params.reply;
+
+	if (params.reply_size < 0)
+		dev_err(dev, "%s: confirmation event 0x%02x/%04x/%02x "
+			"reception failed: %d\n", cmd_name,
+			expected_type, expected_event, cmd->bCommandContext,
+			(int)params.reply_size);
+	return params.reply_size;
+}
+
+
+/**
+ * Generic function for issuing commands to the Radio Control Interface
+ *
+ * @rc:       UWB Radio Control descriptor
+ * @cmd_name: Name of the command being issued (for error messages)
+ * @cmd:      Pointer to rccb structure containing the command;
+ *            normally you embed this structure as the first member of
+ *            the full command structure.
+ * @cmd_size: Size of the whole command buffer pointed to by @cmd.
+ * @reply:    Pointer to the beginning of the confirmation event
+ *            buffer. Normally bigger than an 'struct hwarc_rceb'.
+ *            You need to fill out reply->bEventType and reply->wEvent (in
+ *            cpu order) as the function will use them to verify the
+ *            confirmation event.
+ * @reply_size: Size of the reply buffer
+ *
+ * The function checks that the length returned in the reply is at
+ * least as big as @reply_size; if not, it will be deemed an error and
+ * -EIO returned.
+ *
+ * @rc needs to be referenced
+ */
+ssize_t uwb_rc_cmd(struct uwb_rc *rc, const char *cmd_name,
+		   struct uwb_rccb *cmd, size_t cmd_size,
+		   struct uwb_rceb *reply, size_t reply_size)
+{
+	struct device *dev = &rc->uwb_dev.dev;
+	ssize_t result;
+
+	result = __uwb_rc_cmd(rc, cmd_name,
+			      cmd, cmd_size, reply, reply_size,
+			      reply->bEventType, reply->wEvent, NULL);
+
+	if (result > 0 && result < reply_size) {
+		dev_err(dev, "%s: not enough data returned for decoding reply "
+			"(%zu bytes received vs at least %zu needed)\n",
+			cmd_name, result, reply_size);
+		result = -EIO;
+	}
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_cmd);
+
+
+/**
+ * Generic function for issuing commands to the Radio Control
+ * Interface that return an unknown amount of data
+ *
+ * @rc:       UWB Radio Control descriptor
+ * @cmd_name: Name of the command being issued (for error messages)
+ * @cmd:      Pointer to rccb structure containing the command;
+ *            normally you embed this structure as the first member of
+ *            the full command structure.
+ * @cmd_size: Size of the whole command buffer pointed to by @cmd.
+ * @expected_type: Expected type in the return event
+ * @expected_event: Expected event code in the return event
+ * @preply:   Here a pointer to where the event data is received will
+ *            be stored. Once done with the data, free with kfree().
+ *
+ * The function checks that the length returned in the reply is at
+ * least as big as a 'struct uwb_rceb *'; if not, it will be deemed an
+ * error and -EIO returned.
+ *
+ * @rc needs to be referenced
+ */
+ssize_t uwb_rc_vcmd(struct uwb_rc *rc, const char *cmd_name,
+		    struct uwb_rccb *cmd, size_t cmd_size,
+		    u8 expected_type, u16 expected_event,
+		    struct uwb_rceb **preply)
+{
+	return __uwb_rc_cmd(rc, cmd_name, cmd, cmd_size, NULL, 0,
+			    expected_type, expected_event, preply);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_vcmd);
+
+
+/**
+ * Reset a UWB Host Controller (and all radio settings)
+ *
+ * @rc:      Host Controller descriptor
+ * @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_reset(struct uwb_rc *rc)
+{
+	int result = -ENOMEM;
+	struct uwb_rc_evt_confirm reply;
+	struct uwb_rccb *cmd;
+	size_t cmd_size = sizeof(*cmd);
+
+	mutex_lock(&rc->uwb_dev.mutex);
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	cmd->bCommandType = UWB_RC_CET_GENERAL;
+	cmd->wCommand = cpu_to_le16(UWB_RC_CMD_RESET);
+	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply.rceb.wEvent = UWB_RC_CMD_RESET;
+	result = uwb_rc_cmd(rc, "RESET", cmd, cmd_size,
+			    &reply.rceb, sizeof(reply));
+	if (result < 0)
+		goto error_cmd;
+	if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
+		dev_err(&rc->uwb_dev.dev,
+			"RESET: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
+		result = -EIO;
+	}
+error_cmd:
+	kfree(cmd);
+error_kzalloc:
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return result;
+}
+
+int uwbd_msg_handle_reset(struct uwb_event *evt)
+{
+	struct uwb_rc *rc = evt->rc;
+	int ret;
+
+	/* Need to prevent the RC hardware module going away while in
+	   the rc->reset() call. */
+	if (!try_module_get(rc->owner))
+		return 0;
+
+	dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
+	ret = rc->reset(rc);
+	if (ret)
+		dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
+
+	module_put(rc->owner);
+	return ret;
+}
+
+/**
+ * uwb_rc_reset_all - request a reset of the radio controller and PALs
+ * @rc: the radio controller of the hardware device to be reset.
+ *
+ * The full hardware reset of the radio controller and all the PALs
+ * will be scheduled.
+ */
+void uwb_rc_reset_all(struct uwb_rc *rc)
+{
+	struct uwb_event *evt;
+
+	evt = kzalloc(sizeof(struct uwb_event), GFP_ATOMIC);
+	if (unlikely(evt == NULL))
+		return;
+
+	evt->rc = __uwb_rc_get(rc);	/* will be put by uwbd's uwbd_event_handle() */
+	evt->ts_jiffies = jiffies;
+	evt->type = UWB_EVT_TYPE_MSG;
+	evt->message = UWB_EVT_MSG_RESET;
+
+	uwbd_event_queue(evt);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_reset_all);