driver.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Ultra Wide Band
* Driver initialization, etc
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* FIXME: docs
*
* Life cycle: FIXME: explain
*
* UWB radio controller:
*
* 1. alloc a uwb_rc, zero it
* 2. call uwb_rc_init() on it to set it up + ops (won't do any
* kind of allocation)
* 3. register (now it is owned by the UWB stack--deregister before
* freeing/destroying).
* 4. It lives on it's own now (UWB stack handles)--when it
* disconnects, call unregister()
* 5. free it.
*
* Make sure you have a reference to the uwb_rc before calling
* any of the UWB API functions.
*
* TODO:
*
* 1. Locking and life cycle management is crappy still. All entry
* points to the UWB HCD API assume you have a reference on the
* uwb_rc structure and that it won't go away. They mutex lock it
* before doing anything.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/random.h>
#include "uwb-internal.h"
/* UWB stack attributes (or 'global' constants) */
/**
* If a beacon disappears for longer than this, then we consider the
* device who was represented by that beacon to be gone.
*
* ECMA-368[17.2.3, last para] establishes that a device must not
* consider a device to be its neighbour if he doesn't receive a beacon
* for more than mMaxLostBeacons. mMaxLostBeacons is defined in
* ECMA-368[17.16] as 3; because we can get only one beacon per
* superframe, that'd be 3 * 65ms = 195 ~ 200 ms. Let's give it time
* for jitter and stuff and make it 500 ms.
*/
unsigned long beacon_timeout_ms = 500;
static
ssize_t beacon_timeout_ms_show(struct class *class,
struct class_attribute *attr,
char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%lu\n", beacon_timeout_ms);
}
static
ssize_t beacon_timeout_ms_store(struct class *class,
struct class_attribute *attr,
const char *buf, size_t size)
{
unsigned long bt;
ssize_t result;
result = sscanf(buf, "%lu", &bt);
if (result != 1)
return -EINVAL;
beacon_timeout_ms = bt;
return size;
}
static CLASS_ATTR_RW(beacon_timeout_ms);
static struct attribute *uwb_class_attrs[] = {
&class_attr_beacon_timeout_ms.attr,
NULL,
};
ATTRIBUTE_GROUPS(uwb_class);
/** Device model classes */
struct class uwb_rc_class = {
.name = "uwb_rc",
.class_groups = uwb_class_groups,
};
static int __init uwb_subsys_init(void)
{
int result = 0;
result = uwb_est_create();
if (result < 0) {
printk(KERN_ERR "uwb: Can't initialize EST subsystem\n");
goto error_est_init;
}
result = class_register(&uwb_rc_class);
if (result < 0)
goto error_uwb_rc_class_register;
/* Register the UWB bus */
result = bus_register(&uwb_bus_type);
if (result) {
pr_err("%s - registering bus driver failed\n", __func__);
goto exit_bus;
}
uwb_dbg_init();
return 0;
exit_bus:
class_unregister(&uwb_rc_class);
error_uwb_rc_class_register:
uwb_est_destroy();
error_est_init:
return result;
}
module_init(uwb_subsys_init);
static void __exit uwb_subsys_exit(void)
{
uwb_dbg_exit();
bus_unregister(&uwb_bus_type);
class_unregister(&uwb_rc_class);
uwb_est_destroy();
return;
}
module_exit(uwb_subsys_exit);
MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
MODULE_DESCRIPTION("Ultra Wide Band core");
MODULE_LICENSE("GPL");