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