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
  26#include <linux/kernel.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#define D_LOCAL 1
  34#include <linux/uwb/debug.h>
  35
  36
  37/* We initialize addresses to 0xff (invalid, as it is bcast) */
  38static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  39{
  40        memset(&addr->data, 0xff, sizeof(addr->data));
  41}
  42
  43static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
  44{
  45        memset(&addr->data, 0xff, sizeof(addr->data));
  46}
  47
  48/* @returns !0 if a device @addr is a broadcast address */
  49static inline int uwb_dev_addr_bcast(const struct uwb_dev_addr *addr)
  50{
  51        static const struct uwb_dev_addr bcast = { .data = { 0xff, 0xff } };
  52        return !uwb_dev_addr_cmp(addr, &bcast);
  53}
  54
  55/*
  56 * Add callback @new to be called when an event occurs in @rc.
  57 */
  58int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
  59{
  60        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  61                return -ERESTARTSYS;
  62        list_add(&new->list_node, &rc->notifs_chain.list);
  63        mutex_unlock(&rc->notifs_chain.mutex);
  64        return 0;
  65}
  66EXPORT_SYMBOL_GPL(uwb_notifs_register);
  67
  68/*
  69 * Remove event handler (callback)
  70 */
  71int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
  72{
  73        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  74                return -ERESTARTSYS;
  75        list_del(&entry->list_node);
  76        mutex_unlock(&rc->notifs_chain.mutex);
  77        return 0;
  78}
  79EXPORT_SYMBOL_GPL(uwb_notifs_deregister);
  80
  81/*
  82 * Notify all event handlers of a given event on @rc
  83 *
  84 * We are called with a valid reference to the device, or NULL if the
  85 * event is not for a particular event (e.g., a BG join event).
  86 */
  87void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
  88{
  89        struct uwb_notifs_handler *handler;
  90        if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  91                return;
  92        if (!list_empty(&rc->notifs_chain.list)) {
  93                list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
  94                        handler->cb(handler->data, uwb_dev, event);
  95                }
  96        }
  97        mutex_unlock(&rc->notifs_chain.mutex);
  98}
  99
 100/*
 101 * Release the backing device of a uwb_dev that has been dynamically allocated.
 102 */
 103static void uwb_dev_sys_release(struct device *dev)
 104{
 105        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 106
 107        d_fnstart(4, NULL, "(dev %p uwb_dev %p)\n", dev, uwb_dev);
 108        uwb_bce_put(uwb_dev->bce);
 109        d_printf(0, &uwb_dev->dev, "uwb_dev %p freed\n", uwb_dev);
 110        memset(uwb_dev, 0x69, sizeof(*uwb_dev));
 111        kfree(uwb_dev);
 112        d_fnend(4, NULL, "(dev %p uwb_dev %p) = void\n", dev, uwb_dev);
 113}
 114
 115/*
 116 * Initialize a UWB device instance
 117 *
 118 * Alloc, zero and call this function.
 119 */
 120void uwb_dev_init(struct uwb_dev *uwb_dev)
 121{
 122        mutex_init(&uwb_dev->mutex);
 123        device_initialize(&uwb_dev->dev);
 124        uwb_dev->dev.release = uwb_dev_sys_release;
 125        uwb_dev_addr_init(&uwb_dev->dev_addr);
 126        uwb_mac_addr_init(&uwb_dev->mac_addr);
 127        bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
 128}
 129
 130static ssize_t uwb_dev_EUI_48_show(struct device *dev,
 131                                   struct device_attribute *attr, char *buf)
 132{
 133        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 134        char addr[UWB_ADDR_STRSIZE];
 135
 136        uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
 137        return sprintf(buf, "%s\n", addr);
 138}
 139static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 140
 141static ssize_t uwb_dev_DevAddr_show(struct device *dev,
 142                                    struct device_attribute *attr, char *buf)
 143{
 144        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 145        char addr[UWB_ADDR_STRSIZE];
 146
 147        uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
 148        return sprintf(buf, "%s\n", addr);
 149}
 150static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);
 151
 152/*
 153 * Show the BPST of this device.
 154 *
 155 * Calculated from the receive time of the device's beacon and it's
 156 * slot number.
 157 */
 158static ssize_t uwb_dev_BPST_show(struct device *dev,
 159                                 struct device_attribute *attr, char *buf)
 160{
 161        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 162        struct uwb_beca_e *bce;
 163        struct uwb_beacon_frame *bf;
 164        u16 bpst;
 165
 166        bce = uwb_dev->bce;
 167        mutex_lock(&bce->mutex);
 168        bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
 169        bpst = bce->be->wBPSTOffset
 170                - (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
 171        mutex_unlock(&bce->mutex);
 172
 173        return sprintf(buf, "%d\n", bpst);
 174}
 175static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);
 176
 177/*
 178 * Show the IEs a device is beaconing
 179 *
 180 * We need to access the beacon cache, so we just lock it really
 181 * quick, print the IEs and unlock.
 182 *
 183 * We have a reference on the cache entry, so that should be
 184 * quite safe.
 185 */
 186static ssize_t uwb_dev_IEs_show(struct device *dev,
 187                                struct device_attribute *attr, char *buf)
 188{
 189        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 190
 191        return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
 192}
 193static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 194
 195static ssize_t uwb_dev_LQE_show(struct device *dev,
 196                                struct device_attribute *attr, char *buf)
 197{
 198        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 199        struct uwb_beca_e *bce = uwb_dev->bce;
 200        size_t result;
 201
 202        mutex_lock(&bce->mutex);
 203        result = stats_show(&uwb_dev->bce->lqe_stats, buf);
 204        mutex_unlock(&bce->mutex);
 205        return result;
 206}
 207
 208static ssize_t uwb_dev_LQE_store(struct device *dev,
 209                                 struct device_attribute *attr,
 210                                 const char *buf, size_t size)
 211{
 212        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 213        struct uwb_beca_e *bce = uwb_dev->bce;
 214        ssize_t result;
 215
 216        mutex_lock(&bce->mutex);
 217        result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
 218        mutex_unlock(&bce->mutex);
 219        return result;
 220}
 221static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 222
 223static ssize_t uwb_dev_RSSI_show(struct device *dev,
 224                                 struct device_attribute *attr, char *buf)
 225{
 226        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 227        struct uwb_beca_e *bce = uwb_dev->bce;
 228        size_t result;
 229
 230        mutex_lock(&bce->mutex);
 231        result = stats_show(&uwb_dev->bce->rssi_stats, buf);
 232        mutex_unlock(&bce->mutex);
 233        return result;
 234}
 235
 236static ssize_t uwb_dev_RSSI_store(struct device *dev,
 237                                  struct device_attribute *attr,
 238                                  const char *buf, size_t size)
 239{
 240        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 241        struct uwb_beca_e *bce = uwb_dev->bce;
 242        ssize_t result;
 243
 244        mutex_lock(&bce->mutex);
 245        result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
 246        mutex_unlock(&bce->mutex);
 247        return result;
 248}
 249static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 250
 251
 252static struct attribute *dev_attrs[] = {
 253        &dev_attr_EUI_48.attr,
 254        &dev_attr_DevAddr.attr,
 255        &dev_attr_BPST.attr,
 256        &dev_attr_IEs.attr,
 257        &dev_attr_LQE.attr,
 258        &dev_attr_RSSI.attr,
 259        NULL,
 260};
 261
 262static struct attribute_group dev_attr_group = {
 263        .attrs = dev_attrs,
 264};
 265
 266static struct attribute_group *groups[] = {
 267        &dev_attr_group,
 268        NULL,
 269};
 270
 271/**
 272 * Device SYSFS registration
 273 *
 274 *
 275 */
 276static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
 277{
 278        int result;
 279        struct device *dev;
 280
 281        d_fnstart(4, NULL, "(uwb_dev %p parent_dev %p)\n", uwb_dev, parent_dev);
 282        BUG_ON(parent_dev == NULL);
 283
 284        dev = &uwb_dev->dev;
 285        /* Device sysfs files are only useful for neighbor devices not
 286           local radio controllers. */
 287        if (&uwb_dev->rc->uwb_dev != uwb_dev)
 288                dev->groups = groups;
 289        dev->parent = parent_dev;
 290        dev_set_drvdata(dev, uwb_dev);
 291
 292        result = device_add(dev);
 293        d_fnend(4, NULL, "(uwb_dev %p parent_dev %p) = %d\n", uwb_dev, parent_dev, result);
 294        return result;
 295}
 296
 297
 298static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
 299{
 300        d_fnstart(4, NULL, "(uwb_dev %p)\n", uwb_dev);
 301        dev_set_drvdata(&uwb_dev->dev, NULL);
 302        device_del(&uwb_dev->dev);
 303        d_fnend(4, NULL, "(uwb_dev %p) = void\n", uwb_dev);
 304}
 305
 306
 307/**
 308 * Register and initialize a new UWB device
 309 *
 310 * Did you call uwb_dev_init() on it?
 311 *
 312 * @parent_rc: is the parent radio controller who has the link to the
 313 *             device. When registering the UWB device that is a UWB
 314 *             Radio Controller, we point back to it.
 315 *
 316 * If registering the device that is part of a radio, caller has set
 317 * rc->uwb_dev->dev. Otherwise it is to be left NULL--a new one will
 318 * be allocated.
 319 */
 320int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
 321                struct uwb_rc *parent_rc)
 322{
 323        int result;
 324        struct device *dev;
 325
 326        BUG_ON(uwb_dev == NULL);
 327        BUG_ON(parent_dev == NULL);
 328        BUG_ON(parent_rc == NULL);
 329
 330        mutex_lock(&uwb_dev->mutex);
 331        dev = &uwb_dev->dev;
 332        uwb_dev->rc = parent_rc;
 333        result = __uwb_dev_sys_add(uwb_dev, parent_dev);
 334        if (result < 0)
 335                printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
 336                       dev_name(dev), result);
 337        mutex_unlock(&uwb_dev->mutex);
 338        return result;
 339}
 340
 341
 342void uwb_dev_rm(struct uwb_dev *uwb_dev)
 343{
 344        mutex_lock(&uwb_dev->mutex);
 345        __uwb_dev_sys_rm(uwb_dev);
 346        mutex_unlock(&uwb_dev->mutex);
 347}
 348
 349
 350static
 351int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
 352{
 353        struct uwb_dev *target_uwb_dev = __target_uwb_dev;
 354        struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 355        if (uwb_dev == target_uwb_dev) {
 356                uwb_dev_get(uwb_dev);
 357                return 1;
 358        } else
 359                return 0;
 360}
 361
 362
 363/**
 364 * Given a UWB device descriptor, validate and refcount it
 365 *
 366 * @returns NULL if the device does not exist or is quiescing; the ptr to
 367 *               it otherwise.
 368 */
 369struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
 370{
 371        if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
 372                return uwb_dev;
 373        else
 374                return NULL;
 375}
 376EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 377
 378
 379/**
 380 * Remove a device from the system [grunt for other functions]
 381 */
 382int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
 383{
 384        struct device *dev = &uwb_dev->dev;
 385        char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 386
 387        d_fnstart(3, NULL, "(dev %p [uwb_dev %p], uwb_rc %p)\n", dev, uwb_dev, rc);
 388        uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
 389        uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
 390        dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
 391                 macbuf, devbuf,
 392                 rc ? rc->uwb_dev.dev.parent->bus->name : "n/a",
 393                 rc ? dev_name(rc->uwb_dev.dev.parent) : "");
 394        uwb_dev_rm(uwb_dev);
 395        uwb_dev_put(uwb_dev);   /* for the creation in _onair() */
 396        d_fnend(3, NULL, "(dev %p [uwb_dev %p], uwb_rc %p) = 0\n", dev, uwb_dev, rc);
 397        return 0;
 398}
 399
 400
 401/**
 402 * A device went off the air, clean up after it!
 403 *
 404 * This is called by the UWB Daemon (through the beacon purge function
 405 * uwb_bcn_cache_purge) when it is detected that a device has been in
 406 * radio silence for a while.
 407 *
 408 * If this device is actually a local radio controller we don't need
 409 * to go through the offair process, as it is not registered as that.
 410 *
 411 * NOTE: uwb_bcn_cache.mutex is held!
 412 */
 413void uwbd_dev_offair(struct uwb_beca_e *bce)
 414{
 415        struct uwb_dev *uwb_dev;
 416
 417        uwb_dev = bce->uwb_dev;
 418        if (uwb_dev) {
 419                uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
 420                __uwb_dev_offair(uwb_dev, uwb_dev->rc);
 421        }
 422}
 423
 424
 425/**
 426 * A device went on the air, start it up!
 427 *
 428 * This is called by the UWB Daemon when it is detected that a device
 429 * has popped up in the radio range of the radio controller.
 430 *
 431 * It will just create the freaking device, register the beacon and
 432 * stuff and yatla, done.
 433 *
 434 *
 435 * NOTE: uwb_beca.mutex is held, bce->mutex is held
 436 */
 437void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
 438{
 439        int result;
 440        struct device *dev = &rc->uwb_dev.dev;
 441        struct uwb_dev *uwb_dev;
 442        char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 443
 444        uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
 445        uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
 446        uwb_dev = kzalloc(sizeof(struct uwb_dev), GFP_KERNEL);
 447        if (uwb_dev == NULL) {
 448                dev_err(dev, "new device %s: Cannot allocate memory\n",
 449                        macbuf);
 450                return;
 451        }
 452        uwb_dev_init(uwb_dev);          /* This sets refcnt to one, we own it */
 453        uwb_dev->mac_addr = *bce->mac_addr;
 454        uwb_dev->dev_addr = bce->dev_addr;
 455        dev_set_name(&uwb_dev->dev, macbuf);
 456        result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
 457        if (result < 0) {
 458                dev_err(dev, "new device %s: cannot instantiate device\n",
 459                        macbuf);
 460                goto error_dev_add;
 461        }
 462        /* plug the beacon cache */
 463        bce->uwb_dev = uwb_dev;
 464        uwb_dev->bce = bce;
 465        uwb_bce_get(bce);               /* released in uwb_dev_sys_release() */
 466        dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
 467                 macbuf, devbuf, rc->uwb_dev.dev.parent->bus->name,
 468                 dev_name(rc->uwb_dev.dev.parent));
 469        uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
 470        return;
 471
 472error_dev_add:
 473        kfree(uwb_dev);
 474        return;
 475}
 476
 477/**
 478 * Iterate over the list of UWB devices, calling a @function on each
 479 *
 480 * See docs for bus_for_each()....
 481 *
 482 * @rc:       radio controller for the devices.
 483 * @function: function to call.
 484 * @priv:     data to pass to @function.
 485 * @returns:  0 if no invocation of function() returned a value
 486 *            different to zero. That value otherwise.
 487 */
 488int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f function, void *priv)
 489{
 490        return device_for_each_child(&rc->uwb_dev.dev, priv, function);
 491}
 492EXPORT_SYMBOL_GPL(uwb_dev_for_each);
 493