linux/drivers/uwb/lc-dev.c
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   1/*
   2 * Ultra Wide Band
   3 * Life cycle of devices
   4 *
   5 * Copyright (C) 2005-2006 Intel Corporation
   6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License version
  10 * 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 * 02110-1301, USA.
  21 *
  22 *
  23 * FIXME: docs
  24 */
  25#include <linux/kernel.h>
  26#include <linux/slab.h>
  27#include <linux/device.h>
  28#include <linux/export.h>
  29#include <linux/err.h>
  30#include <linux/kdev_t.h>
  31#include <linux/random.h>
  32#include <linux/stat.h>
  33#include "uwb-internal.h"
  34
  35/* We initialize addresses to 0xff (invalid, as it is bcast) */
  36static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  37{
  38        memset(&addr->data, 0xff, sizeof(addr->data));
  39}
  40
  41static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
  42{
  43        memset(&addr->data, 0xff, sizeof(addr->data));
  44}
  45
  46/* @returns !0 if a device @addr is a broadcast address */
  47static inline int uwb_dev_addr_bcast(const struct uwb_dev_addr *addr)
  48{
  49        static const struct uwb_dev_addr bcast = { .data = { 0xff, 0xff } };
  50        return !uwb_dev_addr_cmp(addr, &bcast);
  51}
  52
  53/*
  54 * Add callback @new to be called when an event occurs in @rc.
  55 */
  56int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
  57{
  58        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  59                return -ERESTARTSYS;
  60        list_add(&new->list_node, &rc->notifs_chain.list);
  61        mutex_unlock(&rc->notifs_chain.mutex);
  62        return 0;
  63}
  64EXPORT_SYMBOL_GPL(uwb_notifs_register);
  65
  66/*
  67 * Remove event handler (callback)
  68 */
  69int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
  70{
  71        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  72                return -ERESTARTSYS;
  73        list_del(&entry->list_node);
  74        mutex_unlock(&rc->notifs_chain.mutex);
  75        return 0;
  76}
  77EXPORT_SYMBOL_GPL(uwb_notifs_deregister);
  78
  79/*
  80 * Notify all event handlers of a given event on @rc
  81 *
  82 * We are called with a valid reference to the device, or NULL if the
  83 * event is not for a particular event (e.g., a BG join event).
  84 */
  85void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
  86{
  87        struct uwb_notifs_handler *handler;
  88        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  89                return;
  90        if (!list_empty(&rc->notifs_chain.list)) {
  91                list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
  92                        handler->cb(handler->data, uwb_dev, event);
  93                }
  94        }
  95        mutex_unlock(&rc->notifs_chain.mutex);
  96}
  97
  98/*
  99 * Release the backing device of a uwb_dev that has been dynamically allocated.
 100 */
 101static void uwb_dev_sys_release(struct device *dev)
 102{
 103        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 104
 105        uwb_bce_put(uwb_dev->bce);
 106        memset(uwb_dev, 0x69, sizeof(*uwb_dev));
 107        kfree(uwb_dev);
 108}
 109
 110/*
 111 * Initialize a UWB device instance
 112 *
 113 * Alloc, zero and call this function.
 114 */
 115void uwb_dev_init(struct uwb_dev *uwb_dev)
 116{
 117        mutex_init(&uwb_dev->mutex);
 118        device_initialize(&uwb_dev->dev);
 119        uwb_dev->dev.release = uwb_dev_sys_release;
 120        uwb_dev_addr_init(&uwb_dev->dev_addr);
 121        uwb_mac_addr_init(&uwb_dev->mac_addr);
 122        bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
 123}
 124
 125static ssize_t uwb_dev_EUI_48_show(struct device *dev,
 126                                   struct device_attribute *attr, char *buf)
 127{
 128        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 129        char addr[UWB_ADDR_STRSIZE];
 130
 131        uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
 132        return sprintf(buf, "%s\n", addr);
 133}
 134static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 135
 136static ssize_t uwb_dev_DevAddr_show(struct device *dev,
 137                                    struct device_attribute *attr, char *buf)
 138{
 139        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 140        char addr[UWB_ADDR_STRSIZE];
 141
 142        uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
 143        return sprintf(buf, "%s\n", addr);
 144}
 145static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);
 146
 147/*
 148 * Show the BPST of this device.
 149 *
 150 * Calculated from the receive time of the device's beacon and it's
 151 * slot number.
 152 */
 153static ssize_t uwb_dev_BPST_show(struct device *dev,
 154                                 struct device_attribute *attr, char *buf)
 155{
 156        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 157        struct uwb_beca_e *bce;
 158        struct uwb_beacon_frame *bf;
 159        u16 bpst;
 160
 161        bce = uwb_dev->bce;
 162        mutex_lock(&bce->mutex);
 163        bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
 164        bpst = bce->be->wBPSTOffset
 165                - (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
 166        mutex_unlock(&bce->mutex);
 167
 168        return sprintf(buf, "%d\n", bpst);
 169}
 170static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);
 171
 172/*
 173 * Show the IEs a device is beaconing
 174 *
 175 * We need to access the beacon cache, so we just lock it really
 176 * quick, print the IEs and unlock.
 177 *
 178 * We have a reference on the cache entry, so that should be
 179 * quite safe.
 180 */
 181static ssize_t uwb_dev_IEs_show(struct device *dev,
 182                                struct device_attribute *attr, char *buf)
 183{
 184        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 185
 186        return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
 187}
 188static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 189
 190static ssize_t uwb_dev_LQE_show(struct device *dev,
 191                                struct device_attribute *attr, char *buf)
 192{
 193        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 194        struct uwb_beca_e *bce = uwb_dev->bce;
 195        size_t result;
 196
 197        mutex_lock(&bce->mutex);
 198        result = stats_show(&uwb_dev->bce->lqe_stats, buf);
 199        mutex_unlock(&bce->mutex);
 200        return result;
 201}
 202
 203static ssize_t uwb_dev_LQE_store(struct device *dev,
 204                                 struct device_attribute *attr,
 205                                 const char *buf, size_t size)
 206{
 207        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 208        struct uwb_beca_e *bce = uwb_dev->bce;
 209        ssize_t result;
 210
 211        mutex_lock(&bce->mutex);
 212        result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
 213        mutex_unlock(&bce->mutex);
 214        return result;
 215}
 216static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 217
 218static ssize_t uwb_dev_RSSI_show(struct device *dev,
 219                                 struct device_attribute *attr, char *buf)
 220{
 221        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 222        struct uwb_beca_e *bce = uwb_dev->bce;
 223        size_t result;
 224
 225        mutex_lock(&bce->mutex);
 226        result = stats_show(&uwb_dev->bce->rssi_stats, buf);
 227        mutex_unlock(&bce->mutex);
 228        return result;
 229}
 230
 231static ssize_t uwb_dev_RSSI_store(struct device *dev,
 232                                  struct device_attribute *attr,
 233                                  const char *buf, size_t size)
 234{
 235        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 236        struct uwb_beca_e *bce = uwb_dev->bce;
 237        ssize_t result;
 238
 239        mutex_lock(&bce->mutex);
 240        result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
 241        mutex_unlock(&bce->mutex);
 242        return result;
 243}
 244static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 245
 246
 247static struct attribute *dev_attrs[] = {
 248        &dev_attr_EUI_48.attr,
 249        &dev_attr_DevAddr.attr,
 250        &dev_attr_BPST.attr,
 251        &dev_attr_IEs.attr,
 252        &dev_attr_LQE.attr,
 253        &dev_attr_RSSI.attr,
 254        NULL,
 255};
 256
 257static struct attribute_group dev_attr_group = {
 258        .attrs = dev_attrs,
 259};
 260
 261static const struct attribute_group *groups[] = {
 262        &dev_attr_group,
 263        NULL,
 264};
 265
 266/**
 267 * Device SYSFS registration
 268 *
 269 *
 270 */
 271static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
 272{
 273        struct device *dev;
 274
 275        dev = &uwb_dev->dev;
 276        /* Device sysfs files are only useful for neighbor devices not
 277           local radio controllers. */
 278        if (&uwb_dev->rc->uwb_dev != uwb_dev)
 279                dev->groups = groups;
 280        dev->parent = parent_dev;
 281        dev_set_drvdata(dev, uwb_dev);
 282
 283        return device_add(dev);
 284}
 285
 286
 287static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
 288{
 289        dev_set_drvdata(&uwb_dev->dev, NULL);
 290        device_del(&uwb_dev->dev);
 291}
 292
 293
 294/**
 295 * Register and initialize a new UWB device
 296 *
 297 * Did you call uwb_dev_init() on it?
 298 *
 299 * @parent_rc: is the parent radio controller who has the link to the
 300 *             device. When registering the UWB device that is a UWB
 301 *             Radio Controller, we point back to it.
 302 *
 303 * If registering the device that is part of a radio, caller has set
 304 * rc->uwb_dev->dev. Otherwise it is to be left NULL--a new one will
 305 * be allocated.
 306 */
 307int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
 308                struct uwb_rc *parent_rc)
 309{
 310        int result;
 311        struct device *dev;
 312
 313        BUG_ON(uwb_dev == NULL);
 314        BUG_ON(parent_dev == NULL);
 315        BUG_ON(parent_rc == NULL);
 316
 317        mutex_lock(&uwb_dev->mutex);
 318        dev = &uwb_dev->dev;
 319        uwb_dev->rc = parent_rc;
 320        result = __uwb_dev_sys_add(uwb_dev, parent_dev);
 321        if (result < 0)
 322                printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
 323                       dev_name(dev), result);
 324        mutex_unlock(&uwb_dev->mutex);
 325        return result;
 326}
 327
 328
 329void uwb_dev_rm(struct uwb_dev *uwb_dev)
 330{
 331        mutex_lock(&uwb_dev->mutex);
 332        __uwb_dev_sys_rm(uwb_dev);
 333        mutex_unlock(&uwb_dev->mutex);
 334}
 335
 336
 337static
 338int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
 339{
 340        struct uwb_dev *target_uwb_dev = __target_uwb_dev;
 341        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 342        if (uwb_dev == target_uwb_dev) {
 343                uwb_dev_get(uwb_dev);
 344                return 1;
 345        } else
 346                return 0;
 347}
 348
 349
 350/**
 351 * Given a UWB device descriptor, validate and refcount it
 352 *
 353 * @returns NULL if the device does not exist or is quiescing; the ptr to
 354 *               it otherwise.
 355 */
 356struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
 357{
 358        if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
 359                return uwb_dev;
 360        else
 361                return NULL;
 362}
 363EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 364
 365
 366/**
 367 * Remove a device from the system [grunt for other functions]
 368 */
 369int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
 370{
 371        struct device *dev = &uwb_dev->dev;
 372        char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 373
 374        uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
 375        uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
 376        dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
 377                 macbuf, devbuf,
 378                 rc ? rc->uwb_dev.dev.parent->bus->name : "n/a",
 379                 rc ? dev_name(rc->uwb_dev.dev.parent) : "");
 380        uwb_dev_rm(uwb_dev);
 381        list_del(&uwb_dev->bce->node);
 382        uwb_bce_put(uwb_dev->bce);
 383        uwb_dev_put(uwb_dev);   /* for the creation in _onair() */
 384
 385        return 0;
 386}
 387
 388
 389/**
 390 * A device went off the air, clean up after it!
 391 *
 392 * This is called by the UWB Daemon (through the beacon purge function
 393 * uwb_bcn_cache_purge) when it is detected that a device has been in
 394 * radio silence for a while.
 395 *
 396 * If this device is actually a local radio controller we don't need
 397 * to go through the offair process, as it is not registered as that.
 398 *
 399 * NOTE: uwb_bcn_cache.mutex is held!
 400 */
 401void uwbd_dev_offair(struct uwb_beca_e *bce)
 402{
 403        struct uwb_dev *uwb_dev;
 404
 405        uwb_dev = bce->uwb_dev;
 406        if (uwb_dev) {
 407                uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
 408                __uwb_dev_offair(uwb_dev, uwb_dev->rc);
 409        }
 410}
 411
 412
 413/**
 414 * A device went on the air, start it up!
 415 *
 416 * This is called by the UWB Daemon when it is detected that a device
 417 * has popped up in the radio range of the radio controller.
 418 *
 419 * It will just create the freaking device, register the beacon and
 420 * stuff and yatla, done.
 421 *
 422 *
 423 * NOTE: uwb_beca.mutex is held, bce->mutex is held
 424 */
 425void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
 426{
 427        int result;
 428        struct device *dev = &rc->uwb_dev.dev;
 429        struct uwb_dev *uwb_dev;
 430        char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 431
 432        uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
 433        uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
 434        uwb_dev = kzalloc(sizeof(struct uwb_dev), GFP_KERNEL);
 435        if (uwb_dev == NULL) {
 436                dev_err(dev, "new device %s: Cannot allocate memory\n",
 437                        macbuf);
 438                return;
 439        }
 440        uwb_dev_init(uwb_dev);          /* This sets refcnt to one, we own it */
 441        uwb_dev->mac_addr = *bce->mac_addr;
 442        uwb_dev->dev_addr = bce->dev_addr;
 443        dev_set_name(&uwb_dev->dev, macbuf);
 444        result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
 445        if (result < 0) {
 446                dev_err(dev, "new device %s: cannot instantiate device\n",
 447                        macbuf);
 448                goto error_dev_add;
 449        }
 450        /* plug the beacon cache */
 451        bce->uwb_dev = uwb_dev;
 452        uwb_dev->bce = bce;
 453        uwb_bce_get(bce);               /* released in uwb_dev_sys_release() */
 454        dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
 455                 macbuf, devbuf, rc->uwb_dev.dev.parent->bus->name,
 456                 dev_name(rc->uwb_dev.dev.parent));
 457        uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
 458        return;
 459
 460error_dev_add:
 461        kfree(uwb_dev);
 462        return;
 463}
 464
 465/**
 466 * Iterate over the list of UWB devices, calling a @function on each
 467 *
 468 * See docs for bus_for_each()....
 469 *
 470 * @rc:       radio controller for the devices.
 471 * @function: function to call.
 472 * @priv:     data to pass to @function.
 473 * @returns:  0 if no invocation of function() returned a value
 474 *            different to zero. That value otherwise.
 475 */
 476int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f function, void *priv)
 477{
 478        return device_for_each_child(&rc->uwb_dev.dev, priv, function);
 479}
 480EXPORT_SYMBOL_GPL(uwb_dev_for_each);
 481
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