uwb: add the UWB stack (core files)

UWB device and radio controller device and event management.
Signed-off-by: David Vrabel <david.vrabel@csr.com>

drivers/uwb/driver.c

+/*
+ * Ultra Wide Band
+ * Driver initialization, etc
+ *
+ * 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
+ *
+ * Life cycle: FIXME: explain
+ *
+ *  UWB radio controller:
+ *
+ *    1. alloc a uwb_rc, zero it
+ *    2. call uwb_rc_init() on it to set it up + ops (won't do any
+ *       kind of allocation)
+ *    3. register (now it is owned by the UWB stack--deregister before
+ *       freeing/destroying).
+ *    4. It lives on it's own now (UWB stack handles)--when it
+ *       disconnects, call unregister()
+ *    5. free it.
+ *
+ *    Make sure you have a reference to the uwb_rc before calling
+ *    any of the UWB API functions.
+ *
+ * TODO:
+ *
+ * 1. Locking and life cycle management is crappy still. All entry
+ *    points to the UWB HCD API assume you have a reference on the
+ *    uwb_rc structure and that it won't go away. They mutex lock it
+ *    before doing anything.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kdev_t.h>
+#include <linux/random.h>
+#include <linux/uwb/debug.h>
+#include "uwb-internal.h"
+
+
+/* UWB stack attributes (or 'global' constants) */
+
+
+/**
+ * If a beacon dissapears for longer than this, then we consider the
+ * device who was represented by that beacon to be gone.
+ *
+ * ECMA-368[17.2.3, last para] establishes that a device must not
+ * consider a device to be its neighbour if he doesn't receive a beacon
+ * for more than mMaxLostBeacons. mMaxLostBeacons is defined in
+ * ECMA-368[17.16] as 3; because we can get only one beacon per
+ * superframe, that'd be 3 * 65ms = 195 ~ 200 ms. Let's give it time
+ * for jitter and stuff and make it 500 ms.
+ */
+unsigned long beacon_timeout_ms = 500;
+
+static
+ssize_t beacon_timeout_ms_show(struct class *class, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%lu\n", beacon_timeout_ms);
+}
+
+static
+ssize_t beacon_timeout_ms_store(struct class *class,
+				const char *buf, size_t size)
+{
+	unsigned long bt;
+	ssize_t result;
+	result = sscanf(buf, "%lu", &bt);
+	if (result != 1)
+		return -EINVAL;
+	beacon_timeout_ms = bt;
+	return size;
+}
+
+static struct class_attribute uwb_class_attrs[] = {
+	__ATTR(beacon_timeout_ms, S_IWUSR | S_IRUGO,
+	       beacon_timeout_ms_show, beacon_timeout_ms_store),
+	__ATTR_NULL,
+};
+
+/** Device model classes */
+struct class uwb_rc_class = {
+	.name        = "uwb_rc",
+	.class_attrs = uwb_class_attrs,
+};
+
+
+static int __init uwb_subsys_init(void)
+{
+	int result = 0;
+
+	result = uwb_est_create();
+	if (result < 0) {
+		printk(KERN_ERR "uwb: Can't initialize EST subsystem\n");
+		goto error_est_init;
+	}
+
+	result = class_register(&uwb_rc_class);
+	if (result < 0)
+		goto error_uwb_rc_class_register;
+	uwbd_start();
+	return 0;
+
+error_uwb_rc_class_register:
+	uwb_est_destroy();
+error_est_init:
+	return result;
+}
+module_init(uwb_subsys_init);
+
+static void __exit uwb_subsys_exit(void)
+{
+	uwbd_stop();
+	class_unregister(&uwb_rc_class);
+	uwb_est_destroy();
+	return;
+}
+module_exit(uwb_subsys_exit);
+
+MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
+MODULE_DESCRIPTION("Ultra Wide Band core");
+MODULE_LICENSE("GPL");

drivers/uwb/lc-dev.c

+/*
+ * Ultra Wide Band
+ * Life cycle of devices
+ *
+ * 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
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kdev_t.h>
+#include <linux/random.h>
+#include "uwb-internal.h"
+
+#define D_LOCAL 1
+#include <linux/uwb/debug.h>
+
+
+/* We initialize addresses to 0xff (invalid, as it is bcast) */
+static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
+{
+	memset(&addr->data, 0xff, sizeof(addr->data));
+}
+
+static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
+{
+	memset(&addr->data, 0xff, sizeof(addr->data));
+}
+
+/* @returns !0 if a device @addr is a broadcast address */
+static inline int uwb_dev_addr_bcast(const struct uwb_dev_addr *addr)
+{
+	static const struct uwb_dev_addr bcast = { .data = { 0xff, 0xff } };
+	return !uwb_dev_addr_cmp(addr, &bcast);
+}
+
+/*
+ * Add callback @new to be called when an event occurs in @rc.
+ */
+int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
+{
+	if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
+		return -ERESTARTSYS;
+	list_add(&new->list_node, &rc->notifs_chain.list);
+	mutex_unlock(&rc->notifs_chain.mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uwb_notifs_register);
+
+/*
+ * Remove event handler (callback)
+ */
+int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
+{
+	if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
+		return -ERESTARTSYS;
+	list_del(&entry->list_node);
+	mutex_unlock(&rc->notifs_chain.mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uwb_notifs_deregister);
+
+/*
+ * Notify all event handlers of a given event on @rc
+ *
+ * We are called with a valid reference to the device, or NULL if the
+ * event is not for a particular event (e.g., a BG join event).
+ */
+void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
+{
+	struct uwb_notifs_handler *handler;
+	if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
+		return;
+	if (!list_empty(&rc->notifs_chain.list)) {
+		list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
+			handler->cb(handler->data, uwb_dev, event);
+		}
+	}
+	mutex_unlock(&rc->notifs_chain.mutex);
+}
+
+/*
+ * Release the backing device of a uwb_dev that has been dynamically allocated.
+ */
+static void uwb_dev_sys_release(struct device *dev)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+
+	d_fnstart(4, NULL, "(dev %p uwb_dev %p)\n", dev, uwb_dev);
+	uwb_bce_put(uwb_dev->bce);
+	d_printf(0, &uwb_dev->dev, "uwb_dev %p freed\n", uwb_dev);
+	memset(uwb_dev, 0x69, sizeof(*uwb_dev));
+	kfree(uwb_dev);
+	d_fnend(4, NULL, "(dev %p uwb_dev %p) = void\n", dev, uwb_dev);
+}
+
+/*
+ * Initialize a UWB device instance
+ *
+ * Alloc, zero and call this function.
+ */
+void uwb_dev_init(struct uwb_dev *uwb_dev)
+{
+	mutex_init(&uwb_dev->mutex);
+	device_initialize(&uwb_dev->dev);
+	uwb_dev->dev.release = uwb_dev_sys_release;
+	uwb_dev_addr_init(&uwb_dev->dev_addr);
+	uwb_mac_addr_init(&uwb_dev->mac_addr);
+	bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
+}
+
+static ssize_t uwb_dev_EUI_48_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	char addr[UWB_ADDR_STRSIZE];
+
+	uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
+	return sprintf(buf, "%s\n", addr);
+}
+static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
+
+static ssize_t uwb_dev_DevAddr_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	char addr[UWB_ADDR_STRSIZE];
+
+	uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
+	return sprintf(buf, "%s\n", addr);
+}
+static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);
+
+/*
+ * Show the BPST of this device.
+ *
+ * Calculated from the receive time of the device's beacon and it's
+ * slot number.
+ */
+static ssize_t uwb_dev_BPST_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_beca_e *bce;
+	struct uwb_beacon_frame *bf;
+	u16 bpst;
+
+	bce = uwb_dev->bce;
+	mutex_lock(&bce->mutex);
+	bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
+	bpst = bce->be->wBPSTOffset
+		- (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
+	mutex_unlock(&bce->mutex);
+
+	return sprintf(buf, "%d\n", bpst);
+}
+static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);
+
+/*
+ * Show the IEs a device is beaconing
+ *
+ * We need to access the beacon cache, so we just lock it really
+ * quick, print the IEs and unlock.
+ *
+ * We have a reference on the cache entry, so that should be
+ * quite safe.
+ */
+static ssize_t uwb_dev_IEs_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+
+	return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
+
+static ssize_t uwb_dev_LQE_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_beca_e *bce = uwb_dev->bce;
+	size_t result;
+
+	mutex_lock(&bce->mutex);
+	result = stats_show(&uwb_dev->bce->lqe_stats, buf);
+	mutex_unlock(&bce->mutex);
+	return result;
+}
+
+static ssize_t uwb_dev_LQE_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_beca_e *bce = uwb_dev->bce;
+	ssize_t result;
+
+	mutex_lock(&bce->mutex);
+	result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
+	mutex_unlock(&bce->mutex);
+	return result;
+}
+static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
+
+static ssize_t uwb_dev_RSSI_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_beca_e *bce = uwb_dev->bce;
+	size_t result;
+
+	mutex_lock(&bce->mutex);
+	result = stats_show(&uwb_dev->bce->rssi_stats, buf);
+	mutex_unlock(&bce->mutex);
+	return result;
+}
+
+static ssize_t uwb_dev_RSSI_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_beca_e *bce = uwb_dev->bce;
+	ssize_t result;
+
+	mutex_lock(&bce->mutex);
+	result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
+	mutex_unlock(&bce->mutex);
+	return result;
+}
+static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
+
+
+static struct attribute *dev_attrs[] = {
+	&dev_attr_EUI_48.attr,
+	&dev_attr_DevAddr.attr,
+	&dev_attr_BPST.attr,
+	&dev_attr_IEs.attr,
+	&dev_attr_LQE.attr,
+	&dev_attr_RSSI.attr,
+	NULL,
+};
+
+static struct attribute_group dev_attr_group = {
+	.attrs = dev_attrs,
+};
+
+static struct attribute_group *groups[] = {
+	&dev_attr_group,
+	NULL,
+};
+
+/**
+ * Device SYSFS registration
+ *
+ *
+ */
+static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
+{
+	int result;
+	struct device *dev;
+
+	d_fnstart(4, NULL, "(uwb_dev %p parent_dev %p)\n", uwb_dev, parent_dev);
+	BUG_ON(parent_dev == NULL);
+
+	dev = &uwb_dev->dev;
+	/* Device sysfs files are only useful for neighbor devices not
+	   local radio controllers. */
+	if (&uwb_dev->rc->uwb_dev != uwb_dev)
+		dev->groups = groups;
+	dev->parent = parent_dev;
+	dev_set_drvdata(dev, uwb_dev);
+
+	result = device_add(dev);
+	d_fnend(4, NULL, "(uwb_dev %p parent_dev %p) = %d\n", uwb_dev, parent_dev, result);
+	return result;
+}
+
+
+static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
+{
+	d_fnstart(4, NULL, "(uwb_dev %p)\n", uwb_dev);
+	dev_set_drvdata(&uwb_dev->dev, NULL);
+	device_del(&uwb_dev->dev);
+	d_fnend(4, NULL, "(uwb_dev %p) = void\n", uwb_dev);
+}
+
+
+/**
+ * Register and initialize a new UWB device
+ *
+ * Did you call uwb_dev_init() on it?
+ *
+ * @parent_rc: is the parent radio controller who has the link to the
+ *             device. When registering the UWB device that is a UWB
+ *             Radio Controller, we point back to it.
+ *
+ * If registering the device that is part of a radio, caller has set
+ * rc->uwb_dev->dev. Otherwise it is to be left NULL--a new one will
+ * be allocated.
+ */
+int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
+		struct uwb_rc *parent_rc)
+{
+	int result;
+	struct device *dev;
+
+	BUG_ON(uwb_dev == NULL);
+	BUG_ON(parent_dev == NULL);
+	BUG_ON(parent_rc == NULL);
+
+	mutex_lock(&uwb_dev->mutex);
+	dev = &uwb_dev->dev;
+	uwb_dev->rc = parent_rc;
+	result = __uwb_dev_sys_add(uwb_dev, parent_dev);
+	if (result < 0)
+		printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
+		       dev_name(dev), result);
+	mutex_unlock(&uwb_dev->mutex);
+	return result;
+}
+
+
+void uwb_dev_rm(struct uwb_dev *uwb_dev)
+{
+	mutex_lock(&uwb_dev->mutex);
+	__uwb_dev_sys_rm(uwb_dev);
+	mutex_unlock(&uwb_dev->mutex);
+}
+
+
+static
+int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
+{
+	struct uwb_dev *target_uwb_dev = __target_uwb_dev;
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	if (uwb_dev == target_uwb_dev) {
+		uwb_dev_get(uwb_dev);
+		return 1;
+	} else
+		return 0;
+}
+
+
+/**
+ * Given a UWB device descriptor, validate and refcount it
+ *
+ * @returns NULL if the device does not exist or is quiescing; the ptr to
+ *               it otherwise.
+ */
+struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
+{
+	if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
+		return uwb_dev;
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(uwb_dev_try_get);
+
+
+/**
+ * Remove a device from the system [grunt for other functions]
+ */
+int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
+{
+	struct device *dev = &uwb_dev->dev;
+	char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
+
+	d_fnstart(3, NULL, "(dev %p [uwb_dev %p], uwb_rc %p)\n", dev, uwb_dev, rc);
+	uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
+	uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
+	dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
+		 macbuf, devbuf,
+		 rc ? rc->uwb_dev.dev.parent->bus->name : "n/a",
+		 rc ? dev_name(rc->uwb_dev.dev.parent) : "");
+	uwb_dev_rm(uwb_dev);
+	uwb_dev_put(uwb_dev);	/* for the creation in _onair() */
+	d_fnend(3, NULL, "(dev %p [uwb_dev %p], uwb_rc %p) = 0\n", dev, uwb_dev, rc);
+	return 0;
+}
+
+
+/**
+ * A device went off the air, clean up after it!
+ *
+ * This is called by the UWB Daemon (through the beacon purge function
+ * uwb_bcn_cache_purge) when it is detected that a device has been in
+ * radio silence for a while.
+ *
+ * If this device is actually a local radio controller we don't need
+ * to go through the offair process, as it is not registered as that.
+ *
+ * NOTE: uwb_bcn_cache.mutex is held!
+ */
+void uwbd_dev_offair(struct uwb_beca_e *bce)
+{
+	struct uwb_dev *uwb_dev;
+
+	uwb_dev = bce->uwb_dev;
+	if (uwb_dev) {
+		uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
+		__uwb_dev_offair(uwb_dev, uwb_dev->rc);
+	}
+}
+
+
+/**
+ * A device went on the air, start it up!
+ *
+ * This is called by the UWB Daemon when it is detected that a device
+ * has popped up in the radio range of the radio controller.
+ *
+ * It will just create the freaking device, register the beacon and
+ * stuff and yatla, done.
+ *
+ *
+ * NOTE: uwb_beca.mutex is held, bce->mutex is held
+ */
+void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
+{
+	int result;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_dev *uwb_dev;
+	char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
+
+	uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
+	uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
+	uwb_dev = kcalloc(1, sizeof(*uwb_dev), GFP_KERNEL);
+	if (uwb_dev == NULL) {
+		dev_err(dev, "new device %s: Cannot allocate memory\n",
+			macbuf);
+		return;
+	}
+	uwb_dev_init(uwb_dev);		/* This sets refcnt to one, we own it */
+	uwb_dev->mac_addr = *bce->mac_addr;
+	uwb_dev->dev_addr = bce->dev_addr;
+	dev_set_name(&uwb_dev->dev, macbuf);
+	result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
+	if (result < 0) {
+		dev_err(dev, "new device %s: cannot instantiate device\n",
+			macbuf);
+		goto error_dev_add;
+	}
+	/* plug the beacon cache */
+	bce->uwb_dev = uwb_dev;
+	uwb_dev->bce = bce;
+	uwb_bce_get(bce);		/* released in uwb_dev_sys_release() */
+	dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
+		 macbuf, devbuf, rc->uwb_dev.dev.parent->bus->name,
+		 dev_name(rc->uwb_dev.dev.parent));
+	uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
+	return;
+
+error_dev_add:
+	kfree(uwb_dev);
+	return;
+}
+
+/**
+ * Iterate over the list of UWB devices, calling a @function on each
+ *
+ * See docs for bus_for_each()....
+ *
+ * @rc:       radio controller for the devices.
+ * @function: function to call.
+ * @priv:     data to pass to @function.
+ * @returns:  0 if no invocation of function() returned a value
+ *            different to zero. That value otherwise.