drivers/staging/rdma/hfi1/device.c

   1 /*
   2  * Copyright(c) 2015, 2016 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47
  48 #include <linux/cdev.h>
  49 #include <linux/module.h>
  50 #include <linux/device.h>
  51 #include <linux/fs.h>
  52
  53 #include "hfi.h"
  54 #include "device.h"
  55
  56 static struct class *class;
  57 static struct class *user_class;
  58 static dev_t hfi1_dev;
  59
  60 int hfi1_cdev_init(int minor, const char *name,
  61                    const struct file_operations *fops,
  62                    struct cdev *cdev, struct device **devp,
  63                    bool user_accessible,
  64                    struct kobject *parent)
  65 {
  66         const dev_t dev = MKDEV(MAJOR(hfi1_dev), minor);
  67         struct device *device = NULL;
  68         int ret;
  69
  70         cdev_init(cdev, fops);
  71         cdev->owner = THIS_MODULE;
  72         cdev->kobj.parent = parent;
  73         kobject_set_name(&cdev->kobj, name);
  74
  75         ret = cdev_add(cdev, dev, 1);
  76         if (ret < 0) {
  77                 pr_err("Could not add cdev for minor %d, %s (err %d)\n",
  78                        minor, name, -ret);
  79                 goto done;
  80         }
  81
  82         if (user_accessible)
  83                 device = device_create(user_class, NULL, dev, NULL, "%s", name);
  84         else
  85                 device = device_create(class, NULL, dev, NULL, "%s", name);
  86
  87         if (IS_ERR(device)) {
  88                 ret = PTR_ERR(device);
  89                 device = NULL;
  90                 pr_err("Could not create device for minor %d, %s (err %d)\n",
  91                         minor, name, -ret);
  92                 cdev_del(cdev);
  93         }
  94 done:
  95         *devp = device;
  96         return ret;
  97 }
  98
  99 void hfi1_cdev_cleanup(struct cdev *cdev, struct device **devp)
 100 {
 101         struct device *device = *devp;
 102
 103         if (device) {
 104                 device_unregister(device);
 105                 *devp = NULL;
 106
 107                 cdev_del(cdev);
 108         }
 109 }
 110
 111 static const char *hfi1_class_name = "hfi1";
 112
 113 const char *class_name(void)
 114 {
 115         return hfi1_class_name;
 116 }
 117
 118 static char *hfi1_devnode(struct device *dev, umode_t *mode)
 119 {
 120         if (mode)
 121                 *mode = 0600;
 122         return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
 123 }
 124
 125 static const char *hfi1_class_name_user = "hfi1_user";
 126 static const char *class_name_user(void)
 127 {
 128         return hfi1_class_name_user;
 129 }
 130
 131 static char *hfi1_user_devnode(struct device *dev, umode_t *mode)
 132 {
 133         if (mode)
 134                 *mode = 0666;
 135         return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
 136 }
 137
 138 int __init dev_init(void)
 139 {
 140         int ret;
 141
 142         ret = alloc_chrdev_region(&hfi1_dev, 0, HFI1_NMINORS, DRIVER_NAME);
 143         if (ret < 0) {
 144                 pr_err("Could not allocate chrdev region (err %d)\n", -ret);
 145                 goto done;
 146         }
 147
 148         class = class_create(THIS_MODULE, class_name());
 149         if (IS_ERR(class)) {
 150                 ret = PTR_ERR(class);
 151                 pr_err("Could not create device class (err %d)\n", -ret);
 152                 unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 153                 goto done;
 154         }
 155         class->devnode = hfi1_devnode;
 156
 157         user_class = class_create(THIS_MODULE, class_name_user());
 158         if (IS_ERR(user_class)) {
 159                 ret = PTR_ERR(user_class);
 160                 pr_err("Could not create device class for user accessible files (err %d)\n",
 161                        -ret);
 162                 class_destroy(class);
 163                 class = NULL;
 164                 user_class = NULL;
 165                 unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 166                 goto done;
 167         }
 168         user_class->devnode = hfi1_user_devnode;
 169
 170 done:
 171         return ret;
 172 }
 173
 174 void dev_cleanup(void)
 175 {
 176         class_destroy(class);
 177         class = NULL;
 178
 179         class_destroy(user_class);
 180         user_class = NULL;
 181
 182         unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 183 }