1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Greybus operations
4 *
5 * Copyright 2015-2016 Google Inc.
6 */
7
8#include <linux/string.h>
9#include <linux/sysfs.h>
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/spinlock.h>
13#include <linux/idr.h>
14
15#include "audio_manager.h"
16#include "audio_manager_private.h"
17
18static struct kset *manager_kset;
19
20static LIST_HEAD(modules_list);
21static DECLARE_RWSEM(modules_rwsem);
22static DEFINE_IDA(module_id);
23
24/* helpers */
25static struct gb_audio_manager_module *gb_audio_manager_get_locked(int id)
26{
27	struct gb_audio_manager_module *module;
28
29	if (id < 0)
30		return NULL;
31
32	list_for_each_entry(module, &modules_list, list) {
33		if (module->id == id)
34			return module;
35	}
36
37	return NULL;
38}
39
40/* public API */
41int gb_audio_manager_add(struct gb_audio_manager_module_descriptor *desc)
42{
43	struct gb_audio_manager_module *module;
44	int id;
45	int err;
46
47	id = ida_simple_get(&module_id, 0, 0, GFP_KERNEL);
48	if (id < 0)
49		return id;
50
51	err = gb_audio_manager_module_create(&module, manager_kset,
52					     id, desc);
53	if (err) {
54		ida_simple_remove(&module_id, id);
55		return err;
56	}
57
58	/* Add it to the list */
59	down_write(&modules_rwsem);
60	list_add_tail(&module->list, &modules_list);
61	up_write(&modules_rwsem);
62
63	return module->id;
64}
65EXPORT_SYMBOL_GPL(gb_audio_manager_add);
66
67int gb_audio_manager_remove(int id)
68{
69	struct gb_audio_manager_module *module;
70
71	down_write(&modules_rwsem);
72
73	module = gb_audio_manager_get_locked(id);
74	if (!module) {
75		up_write(&modules_rwsem);
76		return -EINVAL;
77	}
78	list_del(&module->list);
79	kobject_put(&module->kobj);
80	up_write(&modules_rwsem);
81	ida_simple_remove(&module_id, id);
82	return 0;
83}
84EXPORT_SYMBOL_GPL(gb_audio_manager_remove);
85
86void gb_audio_manager_remove_all(void)
87{
88	struct gb_audio_manager_module *module, *next;
89	int is_empty;
90
91	down_write(&modules_rwsem);
92
93	list_for_each_entry_safe(module, next, &modules_list, list) {
94		list_del(&module->list);
95		ida_simple_remove(&module_id, module->id);
96		kobject_put(&module->kobj);
97	}
98
99	is_empty = list_empty(&modules_list);
100
101	up_write(&modules_rwsem);
102
103	if (!is_empty)
104		pr_warn("Not all nodes were deleted\n");
105}
106EXPORT_SYMBOL_GPL(gb_audio_manager_remove_all);
107
108struct gb_audio_manager_module *gb_audio_manager_get_module(int id)
109{
110	struct gb_audio_manager_module *module;
111
112	down_read(&modules_rwsem);
113	module = gb_audio_manager_get_locked(id);
114	kobject_get(&module->kobj);
115	up_read(&modules_rwsem);
116	return module;
117}
118EXPORT_SYMBOL_GPL(gb_audio_manager_get_module);
119
120void gb_audio_manager_put_module(struct gb_audio_manager_module *module)
121{
122	kobject_put(&module->kobj);
123}
124EXPORT_SYMBOL_GPL(gb_audio_manager_put_module);
125
126int gb_audio_manager_dump_module(int id)
127{
128	struct gb_audio_manager_module *module;
129
130	down_read(&modules_rwsem);
131	module = gb_audio_manager_get_locked(id);
132	up_read(&modules_rwsem);
133
134	if (!module)
135		return -EINVAL;
136
137	gb_audio_manager_module_dump(module);
138	return 0;
139}
140EXPORT_SYMBOL_GPL(gb_audio_manager_dump_module);
141
142void gb_audio_manager_dump_all(void)
143{
144	struct gb_audio_manager_module *module;
145	int count = 0;
146
147	down_read(&modules_rwsem);
148	list_for_each_entry(module, &modules_list, list) {
149		gb_audio_manager_module_dump(module);
150		count++;
151	}
152	up_read(&modules_rwsem);
153
154	pr_info("Number of connected modules: %d\n", count);
155}
156EXPORT_SYMBOL_GPL(gb_audio_manager_dump_all);
157
158/*
159 * module init/deinit
160 */
161static int __init manager_init(void)
162{
163	manager_kset = kset_create_and_add(GB_AUDIO_MANAGER_NAME, NULL,
164					   kernel_kobj);
165	if (!manager_kset)
166		return -ENOMEM;
167
168#ifdef GB_AUDIO_MANAGER_SYSFS
169	gb_audio_manager_sysfs_init(&manager_kset->kobj);
170#endif
171
172	return 0;
173}
174
175static void __exit manager_exit(void)
176{
177	gb_audio_manager_remove_all();
178	kset_unregister(manager_kset);
179	ida_destroy(&module_id);
180}
181
182module_init(manager_init);
183module_exit(manager_exit);
184
185MODULE_LICENSE("GPL");
186MODULE_AUTHOR("Svetlin Ankov <ankov_svetlin@projectara.com>");
187