1 /*
2  * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
3  *
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.
8  *
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.
13  *
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.
17  *
18  * The full GNU General Public License is included in this distribution in the
19  * file called COPYING.
20  */
21 
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>
29 #include <linux/gfp.h>
30 #include <linux/export.h>
31 
32 static struct class *dca_class;
33 static struct idr dca_idr;
34 static spinlock_t dca_idr_lock;
35 
dca_sysfs_add_req(struct dca_provider * dca,struct device * dev,int slot)36 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
37 {
38 	struct device *cd;
39 	static int req_count;
40 
41 	cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
42 			   "requester%d", req_count++);
43 	if (IS_ERR(cd))
44 		return PTR_ERR(cd);
45 	return 0;
46 }
47 
dca_sysfs_remove_req(struct dca_provider * dca,int slot)48 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
49 {
50 	device_destroy(dca_class, MKDEV(0, slot + 1));
51 }
52 
dca_sysfs_add_provider(struct dca_provider * dca,struct device * dev)53 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
54 {
55 	struct device *cd;
56 	int ret;
57 
58 	idr_preload(GFP_KERNEL);
59 	spin_lock(&dca_idr_lock);
60 
61 	ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
62 	if (ret >= 0)
63 		dca->id = ret;
64 
65 	spin_unlock(&dca_idr_lock);
66 	idr_preload_end();
67 	if (ret < 0)
68 		return ret;
69 
70 	cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
71 	if (IS_ERR(cd)) {
72 		spin_lock(&dca_idr_lock);
73 		idr_remove(&dca_idr, dca->id);
74 		spin_unlock(&dca_idr_lock);
75 		return PTR_ERR(cd);
76 	}
77 	dca->cd = cd;
78 	return 0;
79 }
80 
dca_sysfs_remove_provider(struct dca_provider * dca)81 void dca_sysfs_remove_provider(struct dca_provider *dca)
82 {
83 	device_unregister(dca->cd);
84 	dca->cd = NULL;
85 	spin_lock(&dca_idr_lock);
86 	idr_remove(&dca_idr, dca->id);
87 	spin_unlock(&dca_idr_lock);
88 }
89 
dca_sysfs_init(void)90 int __init dca_sysfs_init(void)
91 {
92 	idr_init(&dca_idr);
93 	spin_lock_init(&dca_idr_lock);
94 
95 	dca_class = class_create(THIS_MODULE, "dca");
96 	if (IS_ERR(dca_class)) {
97 		idr_destroy(&dca_idr);
98 		return PTR_ERR(dca_class);
99 	}
100 	return 0;
101 }
102 
dca_sysfs_exit(void)103 void __exit dca_sysfs_exit(void)
104 {
105 	class_destroy(dca_class);
106 	idr_destroy(&dca_idr);
107 }
108 
109