drivers/staging/uwb/lc-dev.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Ultra Wide Band
   4  * Life cycle of devices
   5  *
   6  * Copyright (C) 2005-2006 Intel Corporation
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  *
   9  * FIXME: docs
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/device.h>
  14 #include <linux/export.h>
  15 #include <linux/err.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/random.h>
  18 #include <linux/stat.h>
  19 #include "uwb-internal.h"
  20
  21 /* We initialize addresses to 0xff (invalid, as it is bcast) */
  22 static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
  23 {
  24         memset(&addr->data, 0xff, sizeof(addr->data));
  25 }
  26
  27 static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
  28 {
  29         memset(&addr->data, 0xff, sizeof(addr->data));
  30 }
  31
  32 /*
  33  * Add callback @new to be called when an event occurs in @rc.
  34  */
  35 int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
  36 {
  37         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  38                 return -ERESTARTSYS;
  39         list_add(&new->list_node, &rc->notifs_chain.list);
  40         mutex_unlock(&rc->notifs_chain.mutex);
  41         return 0;
  42 }
  43 EXPORT_SYMBOL_GPL(uwb_notifs_register);
  44
  45 /*
  46  * Remove event handler (callback)
  47  */
  48 int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
  49 {
  50         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  51                 return -ERESTARTSYS;
  52         list_del(&entry->list_node);
  53         mutex_unlock(&rc->notifs_chain.mutex);
  54         return 0;
  55 }
  56 EXPORT_SYMBOL_GPL(uwb_notifs_deregister);
  57
  58 /*
  59  * Notify all event handlers of a given event on @rc
  60  *
  61  * We are called with a valid reference to the device, or NULL if the
  62  * event is not for a particular event (e.g., a BG join event).
  63  */
  64 void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
  65 {
  66         struct uwb_notifs_handler *handler;
  67         if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
  68                 return;
  69         if (!list_empty(&rc->notifs_chain.list)) {
  70                 list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
  71                         handler->cb(handler->data, uwb_dev, event);
  72                 }
  73         }
  74         mutex_unlock(&rc->notifs_chain.mutex);
  75 }
  76
  77 /*
  78  * Release the backing device of a uwb_dev that has been dynamically allocated.
  79  */
  80 static void uwb_dev_sys_release(struct device *dev)
  81 {
  82         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
  83
  84         uwb_bce_put(uwb_dev->bce);
  85         memset(uwb_dev, 0x69, sizeof(*uwb_dev));
  86         kfree(uwb_dev);
  87 }
  88
  89 /*
  90  * Initialize a UWB device instance
  91  *
  92  * Alloc, zero and call this function.
  93  */
  94 void uwb_dev_init(struct uwb_dev *uwb_dev)
  95 {
  96         mutex_init(&uwb_dev->mutex);
  97         device_initialize(&uwb_dev->dev);
  98         uwb_dev->dev.release = uwb_dev_sys_release;
  99         uwb_dev_addr_init(&uwb_dev->dev_addr);
 100         uwb_mac_addr_init(&uwb_dev->mac_addr);
 101         bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
 102 }
 103
 104 static ssize_t uwb_dev_EUI_48_show(struct device *dev,
 105                                    struct device_attribute *attr, char *buf)
 106 {
 107         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 108         char addr[UWB_ADDR_STRSIZE];
 109
 110         uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
 111         return sprintf(buf, "%s\n", addr);
 112 }
 113 static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);
 114
 115 static ssize_t uwb_dev_DevAddr_show(struct device *dev,
 116                                     struct device_attribute *attr, char *buf)
 117 {
 118         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 119         char addr[UWB_ADDR_STRSIZE];
 120
 121         uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
 122         return sprintf(buf, "%s\n", addr);
 123 }
 124 static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);
 125
 126 /*
 127  * Show the BPST of this device.
 128  *
 129  * Calculated from the receive time of the device's beacon and it's
 130  * slot number.
 131  */
 132 static ssize_t uwb_dev_BPST_show(struct device *dev,
 133                                  struct device_attribute *attr, char *buf)
 134 {
 135         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 136         struct uwb_beca_e *bce;
 137         struct uwb_beacon_frame *bf;
 138         u16 bpst;
 139
 140         bce = uwb_dev->bce;
 141         mutex_lock(&bce->mutex);
 142         bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
 143         bpst = bce->be->wBPSTOffset
 144                 - (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
 145         mutex_unlock(&bce->mutex);
 146
 147         return sprintf(buf, "%d\n", bpst);
 148 }
 149 static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);
 150
 151 /*
 152  * Show the IEs a device is beaconing
 153  *
 154  * We need to access the beacon cache, so we just lock it really
 155  * quick, print the IEs and unlock.
 156  *
 157  * We have a reference on the cache entry, so that should be
 158  * quite safe.
 159  */
 160 static ssize_t uwb_dev_IEs_show(struct device *dev,
 161                                 struct device_attribute *attr, char *buf)
 162 {
 163         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 164
 165         return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
 166 }
 167 static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);
 168
 169 static ssize_t uwb_dev_LQE_show(struct device *dev,
 170                                 struct device_attribute *attr, char *buf)
 171 {
 172         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 173         struct uwb_beca_e *bce = uwb_dev->bce;
 174         size_t result;
 175
 176         mutex_lock(&bce->mutex);
 177         result = stats_show(&uwb_dev->bce->lqe_stats, buf);
 178         mutex_unlock(&bce->mutex);
 179         return result;
 180 }
 181
 182 static ssize_t uwb_dev_LQE_store(struct device *dev,
 183                                  struct device_attribute *attr,
 184                                  const char *buf, size_t size)
 185 {
 186         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 187         struct uwb_beca_e *bce = uwb_dev->bce;
 188         ssize_t result;
 189
 190         mutex_lock(&bce->mutex);
 191         result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
 192         mutex_unlock(&bce->mutex);
 193         return result;
 194 }
 195 static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);
 196
 197 static ssize_t uwb_dev_RSSI_show(struct device *dev,
 198                                  struct device_attribute *attr, char *buf)
 199 {
 200         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 201         struct uwb_beca_e *bce = uwb_dev->bce;
 202         size_t result;
 203
 204         mutex_lock(&bce->mutex);
 205         result = stats_show(&uwb_dev->bce->rssi_stats, buf);
 206         mutex_unlock(&bce->mutex);
 207         return result;
 208 }
 209
 210 static ssize_t uwb_dev_RSSI_store(struct device *dev,
 211                                   struct device_attribute *attr,
 212                                   const char *buf, size_t size)
 213 {
 214         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 215         struct uwb_beca_e *bce = uwb_dev->bce;
 216         ssize_t result;
 217
 218         mutex_lock(&bce->mutex);
 219         result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
 220         mutex_unlock(&bce->mutex);
 221         return result;
 222 }
 223 static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);
 224
 225
 226 static struct attribute *uwb_dev_attrs[] = {
 227         &dev_attr_EUI_48.attr,
 228         &dev_attr_DevAddr.attr,
 229         &dev_attr_BPST.attr,
 230         &dev_attr_IEs.attr,
 231         &dev_attr_LQE.attr,
 232         &dev_attr_RSSI.attr,
 233         NULL,
 234 };
 235 ATTRIBUTE_GROUPS(uwb_dev);
 236
 237 /* UWB bus type. */
 238 struct bus_type uwb_bus_type = {
 239         .name =         "uwb",
 240         .dev_groups =   uwb_dev_groups,
 241 };
 242
 243 /**
 244  * Device SYSFS registration
 245  */
 246 static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
 247 {
 248         struct device *dev;
 249
 250         dev = &uwb_dev->dev;
 251         dev->parent = parent_dev;
 252         dev_set_drvdata(dev, uwb_dev);
 253
 254         return device_add(dev);
 255 }
 256
 257
 258 static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
 259 {
 260         dev_set_drvdata(&uwb_dev->dev, NULL);
 261         device_del(&uwb_dev->dev);
 262 }
 263
 264
 265 /**
 266  * Register and initialize a new UWB device
 267  *
 268  * Did you call uwb_dev_init() on it?
 269  *
 270  * @parent_rc: is the parent radio controller who has the link to the
 271  *             device. When registering the UWB device that is a UWB
 272  *             Radio Controller, we point back to it.
 273  *
 274  * If registering the device that is part of a radio, caller has set
 275  * rc->uwb_dev->dev. Otherwise it is to be left NULL--a new one will
 276  * be allocated.
 277  */
 278 int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
 279                 struct uwb_rc *parent_rc)
 280 {
 281         int result;
 282         struct device *dev;
 283
 284         BUG_ON(uwb_dev == NULL);
 285         BUG_ON(parent_dev == NULL);
 286         BUG_ON(parent_rc == NULL);
 287
 288         mutex_lock(&uwb_dev->mutex);
 289         dev = &uwb_dev->dev;
 290         uwb_dev->rc = parent_rc;
 291         result = __uwb_dev_sys_add(uwb_dev, parent_dev);
 292         if (result < 0)
 293                 printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
 294                        dev_name(dev), result);
 295         mutex_unlock(&uwb_dev->mutex);
 296         return result;
 297 }
 298
 299
 300 void uwb_dev_rm(struct uwb_dev *uwb_dev)
 301 {
 302         mutex_lock(&uwb_dev->mutex);
 303         __uwb_dev_sys_rm(uwb_dev);
 304         mutex_unlock(&uwb_dev->mutex);
 305 }
 306
 307
 308 static
 309 int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
 310 {
 311         struct uwb_dev *target_uwb_dev = __target_uwb_dev;
 312         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 313         if (uwb_dev == target_uwb_dev) {
 314                 uwb_dev_get(uwb_dev);
 315                 return 1;
 316         } else
 317                 return 0;
 318 }
 319
 320
 321 /**
 322  * Given a UWB device descriptor, validate and refcount it
 323  *
 324  * @returns NULL if the device does not exist or is quiescing; the ptr to
 325  *               it otherwise.
 326  */
 327 struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
 328 {
 329         if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
 330                 return uwb_dev;
 331         else
 332                 return NULL;
 333 }
 334 EXPORT_SYMBOL_GPL(uwb_dev_try_get);
 335
 336
 337 /**
 338  * Remove a device from the system [grunt for other functions]
 339  */
 340 int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
 341 {
 342         struct device *dev = &uwb_dev->dev;
 343         char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 344
 345         uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
 346         uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
 347         dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
 348                  macbuf, devbuf,
 349                  uwb_dev->dev.bus->name,
 350                  rc ? dev_name(&(rc->uwb_dev.dev)) : "");
 351         uwb_dev_rm(uwb_dev);
 352         list_del(&uwb_dev->bce->node);
 353         uwb_bce_put(uwb_dev->bce);
 354         uwb_dev_put(uwb_dev);   /* for the creation in _onair() */
 355
 356         return 0;
 357 }
 358
 359
 360 /**
 361  * A device went off the air, clean up after it!
 362  *
 363  * This is called by the UWB Daemon (through the beacon purge function
 364  * uwb_bcn_cache_purge) when it is detected that a device has been in
 365  * radio silence for a while.
 366  *
 367  * If this device is actually a local radio controller we don't need
 368  * to go through the offair process, as it is not registered as that.
 369  *
 370  * NOTE: uwb_bcn_cache.mutex is held!
 371  */
 372 void uwbd_dev_offair(struct uwb_beca_e *bce)
 373 {
 374         struct uwb_dev *uwb_dev;
 375
 376         uwb_dev = bce->uwb_dev;
 377         if (uwb_dev) {
 378                 uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
 379                 __uwb_dev_offair(uwb_dev, uwb_dev->rc);
 380         }
 381 }
 382
 383
 384 /**
 385  * A device went on the air, start it up!
 386  *
 387  * This is called by the UWB Daemon when it is detected that a device
 388  * has popped up in the radio range of the radio controller.
 389  *
 390  * It will just create the freaking device, register the beacon and
 391  * stuff and yatla, done.
 392  *
 393  *
 394  * NOTE: uwb_beca.mutex is held, bce->mutex is held
 395  */
 396 void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
 397 {
 398         int result;
 399         struct device *dev = &rc->uwb_dev.dev;
 400         struct uwb_dev *uwb_dev;
 401         char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];
 402
 403         uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
 404         uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
 405         uwb_dev = kzalloc(sizeof(struct uwb_dev), GFP_KERNEL);
 406         if (uwb_dev == NULL) {
 407                 dev_err(dev, "new device %s: Cannot allocate memory\n",
 408                         macbuf);
 409                 return;
 410         }
 411         uwb_dev_init(uwb_dev);          /* This sets refcnt to one, we own it */
 412         uwb_dev->dev.bus = &uwb_bus_type;
 413         uwb_dev->mac_addr = *bce->mac_addr;
 414         uwb_dev->dev_addr = bce->dev_addr;
 415         dev_set_name(&uwb_dev->dev, "%s", macbuf);
 416
 417         /* plug the beacon cache */
 418         bce->uwb_dev = uwb_dev;
 419         uwb_dev->bce = bce;
 420         uwb_bce_get(bce);               /* released in uwb_dev_sys_release() */
 421
 422         result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
 423         if (result < 0) {
 424                 dev_err(dev, "new device %s: cannot instantiate device\n",
 425                         macbuf);
 426                 goto error_dev_add;
 427         }
 428
 429         dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
 430                  macbuf, devbuf, uwb_dev->dev.bus->name,
 431                  dev_name(&(rc->uwb_dev.dev)));
 432         uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
 433         return;
 434
 435 error_dev_add:
 436         bce->uwb_dev = NULL;
 437         uwb_bce_put(bce);
 438         kfree(uwb_dev);
 439         return;
 440 }
 441
 442 /**
 443  * Iterate over the list of UWB devices, calling a @function on each
 444  *
 445  * See docs for bus_for_each()....
 446  *
 447  * @rc:       radio controller for the devices.
 448  * @function: function to call.
 449  * @priv:     data to pass to @function.
 450  * @returns:  0 if no invocation of function() returned a value
 451  *            different to zero. That value otherwise.
 452  */
 453 int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f function, void *priv)
 454 {
 455         return device_for_each_child(&rc->uwb_dev.dev, priv, function);
 456 }
 457 EXPORT_SYMBOL_GPL(uwb_dev_for_each);