1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
4 */
5
6#include <linux/kernel.h>
7#include <linux/spinlock.h>
8#include <linux/device.h>
9#include <linux/idr.h>
10#include <linux/kdev_t.h>
11#include <linux/err.h>
12#include <linux/dca.h>
13#include <linux/gfp.h>
14#include <linux/export.h>
15
16static const struct class dca_class = {
17 .name = "dca",
18};
19static struct idr dca_idr;
20static spinlock_t dca_idr_lock;
21
22int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
23{
24 struct device *cd;
25 static int req_count;
26
27 cd = device_create(cls: &dca_class, parent: dca->cd, MKDEV(0, slot + 1), NULL,
28 fmt: "requester%d", req_count++);
29 return PTR_ERR_OR_ZERO(ptr: cd);
30}
31
32void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
33{
34 device_destroy(cls: &dca_class, MKDEV(0, slot + 1));
35}
36
37int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
38{
39 struct device *cd;
40 int ret;
41
42 idr_preload(GFP_KERNEL);
43 spin_lock(lock: &dca_idr_lock);
44
45 ret = idr_alloc(&dca_idr, ptr: dca, start: 0, end: 0, GFP_NOWAIT);
46 if (ret >= 0)
47 dca->id = ret;
48
49 spin_unlock(lock: &dca_idr_lock);
50 idr_preload_end();
51 if (ret < 0)
52 return ret;
53
54 cd = device_create(cls: &dca_class, parent: dev, MKDEV(0, 0), NULL, fmt: "dca%d", dca->id);
55 if (IS_ERR(ptr: cd)) {
56 spin_lock(lock: &dca_idr_lock);
57 idr_remove(&dca_idr, id: dca->id);
58 spin_unlock(lock: &dca_idr_lock);
59 return PTR_ERR(ptr: cd);
60 }
61 dca->cd = cd;
62 return 0;
63}
64
65void dca_sysfs_remove_provider(struct dca_provider *dca)
66{
67 device_unregister(dev: dca->cd);
68 dca->cd = NULL;
69 spin_lock(lock: &dca_idr_lock);
70 idr_remove(&dca_idr, id: dca->id);
71 spin_unlock(lock: &dca_idr_lock);
72}
73
74int __init dca_sysfs_init(void)
75{
76 int err;
77
78 idr_init(idr: &dca_idr);
79 spin_lock_init(&dca_idr_lock);
80
81 err = class_register(class: &dca_class);
82 if (err) {
83 idr_destroy(&dca_idr);
84 return err;
85 }
86 return 0;
87}
88
89void __exit dca_sysfs_exit(void)
90{
91 class_unregister(class: &dca_class);
92 idr_destroy(&dca_idr);
93}
94
95

source code of linux/drivers/dca/dca-sysfs.c