1/*
2 * UWB PAL support.
3 *
4 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18#include <linux/kernel.h>
19#include <linux/debugfs.h>
20#include <linux/uwb.h>
21#include <linux/export.h>
22
23#include "uwb-internal.h"
24
25/**
26 * uwb_pal_init - initialize a UWB PAL
27 * @pal: the PAL to initialize
28 */
29void uwb_pal_init(struct uwb_pal *pal)
30{
31	INIT_LIST_HEAD(&pal->node);
32}
33EXPORT_SYMBOL_GPL(uwb_pal_init);
34
35/**
36 * uwb_pal_register - register a UWB PAL
37 * @pal: the PAL
38 *
39 * The PAL must be initialized with uwb_pal_init().
40 */
41int uwb_pal_register(struct uwb_pal *pal)
42{
43	struct uwb_rc *rc = pal->rc;
44	int ret;
45
46	if (pal->device) {
47		/* create a link to the uwb_rc in the PAL device's directory. */
48		ret = sysfs_create_link(&pal->device->kobj,
49					&rc->uwb_dev.dev.kobj, "uwb_rc");
50		if (ret < 0)
51			return ret;
52		/* create a link to the PAL in the UWB device's directory. */
53		ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
54					&pal->device->kobj, pal->name);
55		if (ret < 0) {
56			sysfs_remove_link(&pal->device->kobj, "uwb_rc");
57			return ret;
58		}
59	}
60
61	pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);
62
63	mutex_lock(&rc->uwb_dev.mutex);
64	list_add(&pal->node, &rc->pals);
65	mutex_unlock(&rc->uwb_dev.mutex);
66
67	return 0;
68}
69EXPORT_SYMBOL_GPL(uwb_pal_register);
70
71static int find_rc(struct device *dev, const void *data)
72{
73	const struct uwb_rc *target_rc = data;
74	struct uwb_rc *rc = dev_get_drvdata(dev);
75
76	if (rc == NULL) {
77		WARN_ON(1);
78		return 0;
79	}
80	if (rc == target_rc) {
81		if (rc->ready == 0)
82			return 0;
83		else
84			return 1;
85	}
86	return 0;
87}
88
89/**
90 * Given a radio controller descriptor see if it is registered.
91 *
92 * @returns false if the rc does not exist or is quiescing; true otherwise.
93 */
94static bool uwb_rc_class_device_exists(struct uwb_rc *target_rc)
95{
96	struct device *dev;
97
98	dev = class_find_device(&uwb_rc_class, NULL, target_rc,	find_rc);
99
100	return (dev != NULL);
101}
102
103/**
104 * uwb_pal_unregister - unregister a UWB PAL
105 * @pal: the PAL
106 */
107void uwb_pal_unregister(struct uwb_pal *pal)
108{
109	struct uwb_rc *rc = pal->rc;
110
111	uwb_radio_stop(pal);
112
113	mutex_lock(&rc->uwb_dev.mutex);
114	list_del(&pal->node);
115	mutex_unlock(&rc->uwb_dev.mutex);
116
117	debugfs_remove(pal->debugfs_dir);
118
119	if (pal->device) {
120		/* remove link to the PAL in the UWB device's directory. */
121		if (uwb_rc_class_device_exists(rc))
122			sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
123
124		/* remove link to uwb_rc in the PAL device's directory. */
125		sysfs_remove_link(&pal->device->kobj, "uwb_rc");
126	}
127}
128EXPORT_SYMBOL_GPL(uwb_pal_unregister);
129
130/**
131 * uwb_rc_pal_init - initialize the PAL related parts of a radio controller
132 * @rc: the radio controller
133 */
134void uwb_rc_pal_init(struct uwb_rc *rc)
135{
136	INIT_LIST_HEAD(&rc->pals);
137}
138