lc-dev.c

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/*
 * Ultra Wide Band
 * Life cycle of devices
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME: docs
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/random.h>
#include <linux/stat.h>
#include "uwb-internal.h"

/* We initialize addresses to 0xff (invalid, as it is bcast) */
static inline void uwb_dev_addr_init(struct uwb_dev_addr *addr)
{
    memset(&addr->data, 0xff, sizeof(addr->data));
}

static inline void uwb_mac_addr_init(struct uwb_mac_addr *addr)
{
    memset(&addr->data, 0xff, sizeof(addr->data));
}

/* @returns !0 if a device @addr is a broadcast address */
static inline int uwb_dev_addr_bcast(const struct uwb_dev_addr *addr)
{
    static const struct uwb_dev_addr bcast = { .data = { 0xff, 0xff } };
    return !uwb_dev_addr_cmp(addr, &bcast);
}

/*
 * Add callback @new to be called when an event occurs in @rc.
 */
int uwb_notifs_register(struct uwb_rc *rc, struct uwb_notifs_handler *new)
{
    if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
        return -ERESTARTSYS;
    list_add(&new->list_node, &rc->notifs_chain.list);
    mutex_unlock(&rc->notifs_chain.mutex);
    return 0;
}
EXPORT_SYMBOL_GPL(uwb_notifs_register);

/*
 * Remove event handler (callback)
 */
int uwb_notifs_deregister(struct uwb_rc *rc, struct uwb_notifs_handler *entry)
{
    if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
        return -ERESTARTSYS;
    list_del(&entry->list_node);
    mutex_unlock(&rc->notifs_chain.mutex);
    return 0;
}
EXPORT_SYMBOL_GPL(uwb_notifs_deregister);

/*
 * Notify all event handlers of a given event on @rc
 *
 * We are called with a valid reference to the device, or NULL if the
 * event is not for a particular event (e.g., a BG join event).
 */
void uwb_notify(struct uwb_rc *rc, struct uwb_dev *uwb_dev, enum uwb_notifs event)
{
    struct uwb_notifs_handler *handler;
    if (mutex_lock_interruptible(&rc->notifs_chain.mutex))
        return;
    if (!list_empty(&rc->notifs_chain.list)) {
        list_for_each_entry(handler, &rc->notifs_chain.list, list_node) {
            handler->cb(handler->data, uwb_dev, event);
        }
    }
    mutex_unlock(&rc->notifs_chain.mutex);
}

/*
 * Release the backing device of a uwb_dev that has been dynamically allocated.
 */
static void uwb_dev_sys_release(struct device *dev)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);

    uwb_bce_put(uwb_dev->bce);
    memset(uwb_dev, 0x69, sizeof(*uwb_dev));
    kfree(uwb_dev);
}

/*
 * Initialize a UWB device instance
 *
 * Alloc, zero and call this function.
 */
void uwb_dev_init(struct uwb_dev *uwb_dev)
{
    mutex_init(&uwb_dev->mutex);
    device_initialize(&uwb_dev->dev);
    uwb_dev->dev.release = uwb_dev_sys_release;
    uwb_dev_addr_init(&uwb_dev->dev_addr);
    uwb_mac_addr_init(&uwb_dev->mac_addr);
    bitmap_fill(uwb_dev->streams, UWB_NUM_GLOBAL_STREAMS);
}

static ssize_t uwb_dev_EUI_48_show(struct device *dev,
                   struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    char addr[UWB_ADDR_STRSIZE];

    uwb_mac_addr_print(addr, sizeof(addr), &uwb_dev->mac_addr);
    return sprintf(buf, "%s\n", addr);
}
static DEVICE_ATTR(EUI_48, S_IRUGO, uwb_dev_EUI_48_show, NULL);

static ssize_t uwb_dev_DevAddr_show(struct device *dev,
                    struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    char addr[UWB_ADDR_STRSIZE];

    uwb_dev_addr_print(addr, sizeof(addr), &uwb_dev->dev_addr);
    return sprintf(buf, "%s\n", addr);
}
static DEVICE_ATTR(DevAddr, S_IRUGO, uwb_dev_DevAddr_show, NULL);

/*
 * Show the BPST of this device.
 *
 * Calculated from the receive time of the device's beacon and it's
 * slot number.
 */
static ssize_t uwb_dev_BPST_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_beca_e *bce;
    struct uwb_beacon_frame *bf;
    u16 bpst;

    bce = uwb_dev->bce;
    mutex_lock(&bce->mutex);
    bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
    bpst = bce->be->wBPSTOffset
        - (u16)(bf->Beacon_Slot_Number * UWB_BEACON_SLOT_LENGTH_US);
    mutex_unlock(&bce->mutex);

    return sprintf(buf, "%d\n", bpst);
}
static DEVICE_ATTR(BPST, S_IRUGO, uwb_dev_BPST_show, NULL);

/*
 * Show the IEs a device is beaconing
 *
 * We need to access the beacon cache, so we just lock it really
 * quick, print the IEs and unlock.
 *
 * We have a reference on the cache entry, so that should be
 * quite safe.
 */
static ssize_t uwb_dev_IEs_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);

    return uwb_bce_print_IEs(uwb_dev, uwb_dev->bce, buf, PAGE_SIZE);
}
static DEVICE_ATTR(IEs, S_IRUGO | S_IWUSR, uwb_dev_IEs_show, NULL);

static ssize_t uwb_dev_LQE_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_beca_e *bce = uwb_dev->bce;
    size_t result;

    mutex_lock(&bce->mutex);
    result = stats_show(&uwb_dev->bce->lqe_stats, buf);
    mutex_unlock(&bce->mutex);
    return result;
}

static ssize_t uwb_dev_LQE_store(struct device *dev,
                 struct device_attribute *attr,
                 const char *buf, size_t size)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_beca_e *bce = uwb_dev->bce;
    ssize_t result;

    mutex_lock(&bce->mutex);
    result = stats_store(&uwb_dev->bce->lqe_stats, buf, size);
    mutex_unlock(&bce->mutex);
    return result;
}
static DEVICE_ATTR(LQE, S_IRUGO | S_IWUSR, uwb_dev_LQE_show, uwb_dev_LQE_store);

static ssize_t uwb_dev_RSSI_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_beca_e *bce = uwb_dev->bce;
    size_t result;

    mutex_lock(&bce->mutex);
    result = stats_show(&uwb_dev->bce->rssi_stats, buf);
    mutex_unlock(&bce->mutex);
    return result;
}

static ssize_t uwb_dev_RSSI_store(struct device *dev,
                  struct device_attribute *attr,
                  const char *buf, size_t size)
{
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    struct uwb_beca_e *bce = uwb_dev->bce;
    ssize_t result;

    mutex_lock(&bce->mutex);
    result = stats_store(&uwb_dev->bce->rssi_stats, buf, size);
    mutex_unlock(&bce->mutex);
    return result;
}
static DEVICE_ATTR(RSSI, S_IRUGO | S_IWUSR, uwb_dev_RSSI_show, uwb_dev_RSSI_store);


static struct attribute *dev_attrs[] = {
    &dev_attr_EUI_48.attr,
    &dev_attr_DevAddr.attr,
    &dev_attr_BPST.attr,
    &dev_attr_IEs.attr,
    &dev_attr_LQE.attr,
    &dev_attr_RSSI.attr,
    NULL,
};

static struct attribute_group dev_attr_group = {
    .attrs = dev_attrs,
};

static const struct attribute_group *groups[] = {
    &dev_attr_group,
    NULL,
};

static int __uwb_dev_sys_add(struct uwb_dev *uwb_dev, struct device *parent_dev)
{
    struct device *dev;

    dev = &uwb_dev->dev;
    /* Device sysfs files are only useful for neighbor devices not
       local radio controllers. */
    if (&uwb_dev->rc->uwb_dev != uwb_dev)
        dev->groups = groups;
    dev->parent = parent_dev;
    dev_set_drvdata(dev, uwb_dev);

    return device_add(dev);
}


static void __uwb_dev_sys_rm(struct uwb_dev *uwb_dev)
{
    dev_set_drvdata(&uwb_dev->dev, NULL);
    device_del(&uwb_dev->dev);
}


int uwb_dev_add(struct uwb_dev *uwb_dev, struct device *parent_dev,
        struct uwb_rc *parent_rc)
{
    int result;
    struct device *dev;

    BUG_ON(uwb_dev == NULL);
    BUG_ON(parent_dev == NULL);
    BUG_ON(parent_rc == NULL);

    mutex_lock(&uwb_dev->mutex);
    dev = &uwb_dev->dev;
    uwb_dev->rc = parent_rc;
    result = __uwb_dev_sys_add(uwb_dev, parent_dev);
    if (result < 0)
        printk(KERN_ERR "UWB: unable to register dev %s with sysfs: %d\n",
               dev_name(dev), result);
    mutex_unlock(&uwb_dev->mutex);
    return result;
}


void uwb_dev_rm(struct uwb_dev *uwb_dev)
{
    mutex_lock(&uwb_dev->mutex);
    __uwb_dev_sys_rm(uwb_dev);
    mutex_unlock(&uwb_dev->mutex);
}


static
int __uwb_dev_try_get(struct device *dev, void *__target_uwb_dev)
{
    struct uwb_dev *target_uwb_dev = __target_uwb_dev;
    struct uwb_dev *uwb_dev = to_uwb_dev(dev);
    if (uwb_dev == target_uwb_dev) {
        uwb_dev_get(uwb_dev);
        return 1;
    } else
        return 0;
}


struct uwb_dev *uwb_dev_try_get(struct uwb_rc *rc, struct uwb_dev *uwb_dev)
{
    if (uwb_dev_for_each(rc, __uwb_dev_try_get, uwb_dev))
        return uwb_dev;
    else
        return NULL;
}
EXPORT_SYMBOL_GPL(uwb_dev_try_get);


int __uwb_dev_offair(struct uwb_dev *uwb_dev, struct uwb_rc *rc)
{
    struct device *dev = &uwb_dev->dev;
    char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];

    uwb_mac_addr_print(macbuf, sizeof(macbuf), &uwb_dev->mac_addr);
    uwb_dev_addr_print(devbuf, sizeof(devbuf), &uwb_dev->dev_addr);
    dev_info(dev, "uwb device (mac %s dev %s) disconnected from %s %s\n",
         macbuf, devbuf,
         rc ? rc->uwb_dev.dev.parent->bus->name : "n/a",
         rc ? dev_name(rc->uwb_dev.dev.parent) : "");
    uwb_dev_rm(uwb_dev);
    list_del(&uwb_dev->bce->node);
    uwb_bce_put(uwb_dev->bce);
    uwb_dev_put(uwb_dev);   /* for the creation in _onair() */

    return 0;
}


void uwbd_dev_offair(struct uwb_beca_e *bce)
{
    struct uwb_dev *uwb_dev;

    uwb_dev = bce->uwb_dev;
    if (uwb_dev) {
        uwb_notify(uwb_dev->rc, uwb_dev, UWB_NOTIF_OFFAIR);
        __uwb_dev_offair(uwb_dev, uwb_dev->rc);
    }
}


void uwbd_dev_onair(struct uwb_rc *rc, struct uwb_beca_e *bce)
{
    int result;
    struct device *dev = &rc->uwb_dev.dev;
    struct uwb_dev *uwb_dev;
    char macbuf[UWB_ADDR_STRSIZE], devbuf[UWB_ADDR_STRSIZE];

    uwb_mac_addr_print(macbuf, sizeof(macbuf), bce->mac_addr);
    uwb_dev_addr_print(devbuf, sizeof(devbuf), &bce->dev_addr);
    uwb_dev = kzalloc(sizeof(struct uwb_dev), GFP_KERNEL);
    if (uwb_dev == NULL) {
        dev_err(dev, "new device %s: Cannot allocate memory\n",
            macbuf);
        return;
    }
    uwb_dev_init(uwb_dev);      /* This sets refcnt to one, we own it */
    uwb_dev->mac_addr = *bce->mac_addr;
    uwb_dev->dev_addr = bce->dev_addr;
    dev_set_name(&uwb_dev->dev, macbuf);
    result = uwb_dev_add(uwb_dev, &rc->uwb_dev.dev, rc);
    if (result < 0) {
        dev_err(dev, "new device %s: cannot instantiate device\n",
            macbuf);
        goto error_dev_add;
    }
    /* plug the beacon cache */
    bce->uwb_dev = uwb_dev;
    uwb_dev->bce = bce;
    uwb_bce_get(bce);       /* released in uwb_dev_sys_release() */
    dev_info(dev, "uwb device (mac %s dev %s) connected to %s %s\n",
         macbuf, devbuf, rc->uwb_dev.dev.parent->bus->name,
         dev_name(rc->uwb_dev.dev.parent));
    uwb_notify(rc, uwb_dev, UWB_NOTIF_ONAIR);
    return;

error_dev_add:
    kfree(uwb_dev);
    return;
}

int uwb_dev_for_each(struct uwb_rc *rc, uwb_dev_for_each_f function, void *priv)
{
    return device_for_each_child(&rc->uwb_dev.dev, priv, function);
}
EXPORT_SYMBOL_GPL(uwb_dev_for_each);