drivers/uwb/lc-dev.c

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