LXR linux/drivers/uwb/driver.c

   1/*
   2 * Ultra Wide Band
   3 * Driver initialization, etc
   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 * Life cycle: FIXME: explain
  26 *
  27 *  UWB radio controller:
  28 *
  29 *    1. alloc a uwb_rc, zero it
  30 *    2. call uwb_rc_init() on it to set it up + ops (won't do any
  31 *       kind of allocation)
  32 *    3. register (now it is owned by the UWB stack--deregister before
  33 *       freeing/destroying).
  34 *    4. It lives on it's own now (UWB stack handles)--when it
  35 *       disconnects, call unregister()
  36 *    5. free it.
  37 *
  38 *    Make sure you have a reference to the uwb_rc before calling
  39 *    any of the UWB API functions.
  40 *
  41 * TODO:
  42 *
  43 * 1. Locking and life cycle management is crappy still. All entry
  44 *    points to the UWB HCD API assume you have a reference on the
  45 *    uwb_rc structure and that it won't go away. They mutex lock it
  46 *    before doing anything.
  47 */
  48
  49#include <linux/kernel.h>
  50#include <linux/init.h>
  51#include <linux/module.h>
  52#include <linux/device.h>
  53#include <linux/err.h>
  54#include <linux/kdev_t.h>
  55#include <linux/random.h>
  56
  57#include "uwb-internal.h"
  58
  59
  60/* UWB stack attributes (or 'global' constants) */
  61
  62
  63/**
  64 * If a beacon disappears for longer than this, then we consider the
  65 * device who was represented by that beacon to be gone.
  66 *
  67 * ECMA-368[17.2.3, last para] establishes that a device must not
  68 * consider a device to be its neighbour if he doesn't receive a beacon
  69 * for more than mMaxLostBeacons. mMaxLostBeacons is defined in
  70 * ECMA-368[17.16] as 3; because we can get only one beacon per
  71 * superframe, that'd be 3 * 65ms = 195 ~ 200 ms. Let's give it time
  72 * for jitter and stuff and make it 500 ms.
  73 */
  74unsigned long beacon_timeout_ms = 500;
  75
  76static
  77ssize_t beacon_timeout_ms_show(struct class *class,
  78                                struct class_attribute *attr,
  79                                char *buf)
  80{
  81        return scnprintf(buf, PAGE_SIZE, "%lu\n", beacon_timeout_ms);
  82}
  83
  84static
  85ssize_t beacon_timeout_ms_store(struct class *class,
  86                                struct class_attribute *attr,
  87                                const char *buf, size_t size)
  88{
  89        unsigned long bt;
  90        ssize_t result;
  91        result = sscanf(buf, "%lu", &bt);
  92        if (result != 1)
  93                return -EINVAL;
  94        beacon_timeout_ms = bt;
  95        return size;
  96}
  97
  98static struct class_attribute uwb_class_attrs[] = {
  99        __ATTR(beacon_timeout_ms, S_IWUSR | S_IRUGO,
 100               beacon_timeout_ms_show, beacon_timeout_ms_store),
 101        __ATTR_NULL,
 102};
 103
 104/** Device model classes */
 105struct class uwb_rc_class = {
 106        .name        = "uwb_rc",
 107        .class_attrs = uwb_class_attrs,
 108};
 109
 110
 111static int __init uwb_subsys_init(void)
 112{
 113        int result = 0;
 114
 115        result = uwb_est_create();
 116        if (result < 0) {
 117                printk(KERN_ERR "uwb: Can't initialize EST subsystem\n");
 118                goto error_est_init;
 119        }
 120
 121        result = class_register(&uwb_rc_class);
 122        if (result < 0)
 123                goto error_uwb_rc_class_register;
 124
 125        /* Register the UWB bus */
 126        result = bus_register(&uwb_bus_type);
 127        if (result) {
 128                pr_err("%s - registering bus driver failed\n", __func__);
 129                goto exit_bus;
 130        }
 131
 132        uwb_dbg_init();
 133        return 0;
 134
 135exit_bus:
 136        class_unregister(&uwb_rc_class);
 137error_uwb_rc_class_register:
 138        uwb_est_destroy();
 139error_est_init:
 140        return result;
 141}
 142module_init(uwb_subsys_init);
 143
 144static void __exit uwb_subsys_exit(void)
 145{
 146        uwb_dbg_exit();
 147        bus_unregister(&uwb_bus_type);
 148        class_unregister(&uwb_rc_class);
 149        uwb_est_destroy();
 150        return;
 151}
 152module_exit(uwb_subsys_exit);
 153
 154MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 155MODULE_DESCRIPTION("Ultra Wide Band core");
 156MODULE_LICENSE("GPL");
 157