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  */
74 unsigned long beacon_timeout_ms = 500;
75 
76 static
beacon_timeout_ms_show(struct class * class,struct class_attribute * attr,char * buf)77 ssize_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 
84 static
beacon_timeout_ms_store(struct class * class,struct class_attribute * attr,const char * buf,size_t size)85 ssize_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 static CLASS_ATTR_RW(beacon_timeout_ms);
98 
99 static struct attribute *uwb_class_attrs[] = {
100 	&class_attr_beacon_timeout_ms.attr,
101 	NULL,
102 };
103 ATTRIBUTE_GROUPS(uwb_class);
104 
105 /** Device model classes */
106 struct class uwb_rc_class = {
107 	.name        = "uwb_rc",
108 	.class_groups = uwb_class_groups,
109 };
110 
111 
uwb_subsys_init(void)112 static int __init uwb_subsys_init(void)
113 {
114 	int result = 0;
115 
116 	result = uwb_est_create();
117 	if (result < 0) {
118 		printk(KERN_ERR "uwb: Can't initialize EST subsystem\n");
119 		goto error_est_init;
120 	}
121 
122 	result = class_register(&uwb_rc_class);
123 	if (result < 0)
124 		goto error_uwb_rc_class_register;
125 
126 	/* Register the UWB bus */
127 	result = bus_register(&uwb_bus_type);
128 	if (result) {
129 		pr_err("%s - registering bus driver failed\n", __func__);
130 		goto exit_bus;
131 	}
132 
133 	uwb_dbg_init();
134 	return 0;
135 
136 exit_bus:
137 	class_unregister(&uwb_rc_class);
138 error_uwb_rc_class_register:
139 	uwb_est_destroy();
140 error_est_init:
141 	return result;
142 }
143 module_init(uwb_subsys_init);
144 
uwb_subsys_exit(void)145 static void __exit uwb_subsys_exit(void)
146 {
147 	uwb_dbg_exit();
148 	bus_unregister(&uwb_bus_type);
149 	class_unregister(&uwb_rc_class);
150 	uwb_est_destroy();
151 	return;
152 }
153 module_exit(uwb_subsys_exit);
154 
155 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
156 MODULE_DESCRIPTION("Ultra Wide Band core");
157 MODULE_LICENSE("GPL");
158