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/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) */
  36 static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  37 {
  38         memset(&addr->data, 0xff, sizeof(addr->data));
  39 }
  40
  41 static 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 */
  47 static 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  */
  56 int 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 }
  64 EXPORT_SYMBOL_GPL(uwb_notifs_register);
  65
  66 /*
  67  * Remove event handler (callback)
  68  */
  69 int 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 }
  77 EXPORT_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  */
  85 void 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  */
 101 static 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  */
 115 void 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
 125 static 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 }
 134 static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 135
 136 static 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 }
 145 static 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  */
 153 static 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 }
 170 static 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  */
 181 static 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 }
 188 static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 189
 190 static 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
 203 static 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 }
 216 static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 217
 218 static 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
 231 static 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 }
 244 static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 245
 246
 247 static 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
 257 static struct attribute_group dev_attr_group = {
 258         .attrs = dev_attrs,
 259 };
 260
 261 static const struct attribute_group *groups[] = {
 262         &dev_attr_group,
 263         NULL,
 264 };
 265
 266 /**
 267  * Device SYSFS registration
 268  *
 269  *
 270  */
 271 static 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
 287 static 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  */
 307 int 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
 329 void 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
 337 static
 338 int __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  */
 356 struct 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 }
 363 EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 364
 365
 366 /**
 367  * Remove a device from the system [grunt for other functions]
 368  */
 369 int __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  */
 401 void 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  */
 425 void 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
 460 error_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  */
 476 int 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 }
 480 EXPORT_SYMBOL_GPL(uwb_dev_for_each);