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
  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) */
  38 static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  39 {
  40         memset(&addr->data, 0xff, sizeof(addr->data));
  41 }
  42
  43 static 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 */
  49 static 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  */
  58 int 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 }
  66 EXPORT_SYMBOL_GPL(uwb_notifs_register);
  67
  68 /*
  69  * Remove event handler (callback)
  70  */
  71 int 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 }
  79 EXPORT_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  */
  87 void 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  */
 103 static 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  */
 120 void 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
 130 static 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 }
 139 static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 140
 141 static 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 }
 150 static 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  */
 158 static 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 }
 175 static 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  */
 186 static 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 }
 193 static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 194
 195 static 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
 208 static 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 }
 221 static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 222
 223 static 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
 236 static 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 }
 249 static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 250
 251
 252 static 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
 262 static struct attribute_group dev_attr_group = {
 263         .attrs = dev_attrs,
 264 };
 265
 266 static struct attribute_group *groups[] = {
 267         &dev_attr_group,
 268         NULL,
 269 };
 270
 271 /**
 272  * Device SYSFS registration
 273  *
 274  *
 275  */
 276 static 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
 298 static 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  */
 320 int 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
 342 void 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
 350 static
 351 int __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  */
 369 struct 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 }
 376 EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 377
 378
 379 /**
 380  * Remove a device from the system [grunt for other functions]
 381  */
 382 int __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  */
 413 void 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  */
 437 void 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
 472 error_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  */
 488 int 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 }
 492 EXPORT_SYMBOL_GPL(uwb_dev_for_each);