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 31 static struct class *dca_class; 32 static struct idr dca_idr; 33 static spinlock_t dca_idr_lock; 34 35 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot) 36 { 37 struct device *cd; 38 static int req_count; 39 40 cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL, 41 "requester%d", req_count++); 42 if (IS_ERR(cd)) 43 return PTR_ERR(cd); 44 return 0; 45 } 46 47 void dca_sysfs_remove_req(struct dca_provider *dca, int slot) 48 { 49 device_destroy(dca_class, MKDEV(0, slot + 1)); 50 } 51 52 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev) 53 { 54 struct device *cd; 55 int err = 0; 56 57 idr_try_again: 58 if (!idr_pre_get(&dca_idr, GFP_KERNEL)) 59 return -ENOMEM; 60 spin_lock(&dca_idr_lock); 61 err = idr_get_new(&dca_idr, dca, &dca->id); 62 spin_unlock(&dca_idr_lock); 63 switch (err) { 64 case 0: 65 break; 66 case -EAGAIN: 67 goto idr_try_again; 68 default: 69 return err; 70 } 71 72 cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id); 73 if (IS_ERR(cd)) { 74 spin_lock(&dca_idr_lock); 75 idr_remove(&dca_idr, dca->id); 76 spin_unlock(&dca_idr_lock); 77 return PTR_ERR(cd); 78 } 79 dca->cd = cd; 80 return 0; 81 } 82 83 void dca_sysfs_remove_provider(struct dca_provider *dca) 84 { 85 device_unregister(dca->cd); 86 dca->cd = NULL; 87 spin_lock(&dca_idr_lock); 88 idr_remove(&dca_idr, dca->id); 89 spin_unlock(&dca_idr_lock); 90 } 91 92 int __init dca_sysfs_init(void) 93 { 94 idr_init(&dca_idr); 95 spin_lock_init(&dca_idr_lock); 96 97 dca_class = class_create(THIS_MODULE, "dca"); 98 if (IS_ERR(dca_class)) { 99 idr_destroy(&dca_idr); 100 return PTR_ERR(dca_class); 101 } 102 return 0; 103 } 104 105 void __exit dca_sysfs_exit(void) 106 { 107 class_destroy(dca_class); 108 idr_destroy(&dca_idr); 109 } 110 111