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 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 48 void dca_sysfs_remove_req(struct dca_provider *dca, int slot) 49 { 50 device_destroy(dca_class, MKDEV(0, slot + 1)); 51 } 52 53 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev) 54 { 55 struct device *cd; 56 int err = 0; 57 58 idr_try_again: 59 if (!idr_pre_get(&dca_idr, GFP_KERNEL)) 60 return -ENOMEM; 61 spin_lock(&dca_idr_lock); 62 err = idr_get_new(&dca_idr, dca, &dca->id); 63 spin_unlock(&dca_idr_lock); 64 switch (err) { 65 case 0: 66 break; 67 case -EAGAIN: 68 goto idr_try_again; 69 default: 70 return err; 71 } 72 73 cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id); 74 if (IS_ERR(cd)) { 75 spin_lock(&dca_idr_lock); 76 idr_remove(&dca_idr, dca->id); 77 spin_unlock(&dca_idr_lock); 78 return PTR_ERR(cd); 79 } 80 dca->cd = cd; 81 return 0; 82 } 83 84 void dca_sysfs_remove_provider(struct dca_provider *dca) 85 { 86 device_unregister(dca->cd); 87 dca->cd = NULL; 88 spin_lock(&dca_idr_lock); 89 idr_remove(&dca_idr, dca->id); 90 spin_unlock(&dca_idr_lock); 91 } 92 93 int __init dca_sysfs_init(void) 94 { 95 idr_init(&dca_idr); 96 spin_lock_init(&dca_idr_lock); 97 98 dca_class = class_create(THIS_MODULE, "dca"); 99 if (IS_ERR(dca_class)) { 100 idr_destroy(&dca_idr); 101 return PTR_ERR(dca_class); 102 } 103 return 0; 104 } 105 106 void __exit dca_sysfs_exit(void) 107 { 108 class_destroy(dca_class); 109 idr_destroy(&dca_idr); 110 } 111 112