ACPI: pci_root: simplify list traversals
[linux-2.6/linux-acpi-2.6.git] / drivers / dca / dca-sysfs.c
blobee916c9857eed0896460e6efb65451082ddbe593
1 /*
2 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; either version 2 of the License, or (at your option)
7 * any later version.
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59
16 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * The full GNU General Public License is included in this distribution in the
19 * file called COPYING.
22 #include <linux/kernel.h>
23 #include <linux/spinlock.h>
24 #include <linux/device.h>
25 #include <linux/idr.h>
26 #include <linux/kdev_t.h>
27 #include <linux/err.h>
28 #include <linux/dca.h>
30 static struct class *dca_class;
31 static struct idr dca_idr;
32 static spinlock_t dca_idr_lock;
34 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
36 struct device *cd;
37 static int req_count;
39 cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
40 "requester%d", req_count++);
41 if (IS_ERR(cd))
42 return PTR_ERR(cd);
43 return 0;
46 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
48 device_destroy(dca_class, MKDEV(0, slot + 1));
51 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
53 struct device *cd;
54 int err = 0;
56 idr_try_again:
57 if (!idr_pre_get(&dca_idr, GFP_KERNEL))
58 return -ENOMEM;
59 spin_lock(&dca_idr_lock);
60 err = idr_get_new(&dca_idr, dca, &dca->id);
61 spin_unlock(&dca_idr_lock);
62 switch (err) {
63 case 0:
64 break;
65 case -EAGAIN:
66 goto idr_try_again;
67 default:
68 return err;
71 cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
72 if (IS_ERR(cd)) {
73 spin_lock(&dca_idr_lock);
74 idr_remove(&dca_idr, dca->id);
75 spin_unlock(&dca_idr_lock);
76 return PTR_ERR(cd);
78 dca->cd = cd;
79 return 0;
82 void dca_sysfs_remove_provider(struct dca_provider *dca)
84 device_unregister(dca->cd);
85 dca->cd = NULL;
86 spin_lock(&dca_idr_lock);
87 idr_remove(&dca_idr, dca->id);
88 spin_unlock(&dca_idr_lock);
91 int __init dca_sysfs_init(void)
93 idr_init(&dca_idr);
94 spin_lock_init(&dca_idr_lock);
96 dca_class = class_create(THIS_MODULE, "dca");
97 if (IS_ERR(dca_class)) {
98 idr_destroy(&dca_idr);
99 return PTR_ERR(dca_class);
101 return 0;
104 void __exit dca_sysfs_exit(void)
106 class_destroy(dca_class);
107 idr_destroy(&dca_idr);