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 30 static struct class *dca_class; 31 static struct idr dca_idr; 32 static spinlock_t dca_idr_lock; 33 34 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot) 35 { 36 struct device *cd; 37 static int req_count; 38 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; 44 } 45 46 void dca_sysfs_remove_req(struct dca_provider *dca, int slot) 47 { 48 device_destroy(dca_class, MKDEV(0, slot + 1)); 49 } 50 51 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev) 52 { 53 struct device *cd; 54 int err = 0; 55 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; 69 } 70 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); 77 } 78 dca->cd = cd; 79 return 0; 80 } 81 82 void dca_sysfs_remove_provider(struct dca_provider *dca) 83 { 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); 89 } 90 91 int __init dca_sysfs_init(void) 92 { 93 idr_init(&dca_idr); 94 spin_lock_init(&dca_idr_lock); 95 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); 100 } 101 return 0; 102 } 103 104 void __exit dca_sysfs_exit(void) 105 { 106 class_destroy(dca_class); 107 idr_destroy(&dca_idr); 108 } 109 110