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 {
  65         const dev_t dev = MKDEV(MAJOR(hfi1_dev), minor);
  66         struct device *device = NULL;
  67         int ret;
  68
  69         cdev_init(cdev, fops);
  70         cdev->owner = THIS_MODULE;
  71         kobject_set_name(&cdev->kobj, name);
  72
  73         ret = cdev_add(cdev, dev, 1);
  74         if (ret < 0) {
  75                 pr_err("Could not add cdev for minor %d, %s (err %d)\n",
  76                        minor, name, -ret);
  77                 goto done;
  78         }
  79
  80         if (user_accessible)
  81                 device = device_create(user_class, NULL, dev, NULL, "%s", name);
  82         else
  83                 device = device_create(class, NULL, dev, NULL, "%s", name);
  84
  85         if (!IS_ERR(device))
  86                 goto done;
  87         ret = PTR_ERR(device);
  88         device = NULL;
  89         pr_err("Could not create device for minor %d, %s (err %d)\n",
  90                minor, name, -ret);
  91         cdev_del(cdev);
  92 done:
  93         *devp = device;
  94         return ret;
  95 }
  96
  97 void hfi1_cdev_cleanup(struct cdev *cdev, struct device **devp)
  98 {
  99         struct device *device = *devp;
 100
 101         if (device) {
 102                 device_unregister(device);
 103                 *devp = NULL;
 104
 105                 cdev_del(cdev);
 106         }
 107 }
 108
 109 static const char *hfi1_class_name = "hfi1";
 110
 111 const char *class_name(void)
 112 {
 113         return hfi1_class_name;
 114 }
 115
 116 static char *hfi1_devnode(struct device *dev, umode_t *mode)
 117 {
 118         if (mode)
 119                 *mode = 0600;
 120         return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
 121 }
 122
 123 static const char *hfi1_class_name_user = "hfi1_user";
 124 static const char *class_name_user(void)
 125 {
 126         return hfi1_class_name_user;
 127 }
 128
 129 static char *hfi1_user_devnode(struct device *dev, umode_t *mode)
 130 {
 131         if (mode)
 132                 *mode = 0666;
 133         return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
 134 }
 135
 136 int __init dev_init(void)
 137 {
 138         int ret;
 139
 140         ret = alloc_chrdev_region(&hfi1_dev, 0, HFI1_NMINORS, DRIVER_NAME);
 141         if (ret < 0) {
 142                 pr_err("Could not allocate chrdev region (err %d)\n", -ret);
 143                 goto done;
 144         }
 145
 146         class = class_create(THIS_MODULE, class_name());
 147         if (IS_ERR(class)) {
 148                 ret = PTR_ERR(class);
 149                 pr_err("Could not create device class (err %d)\n", -ret);
 150                 unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 151                 goto done;
 152         }
 153         class->devnode = hfi1_devnode;
 154
 155         user_class = class_create(THIS_MODULE, class_name_user());
 156         if (IS_ERR(user_class)) {
 157                 ret = PTR_ERR(user_class);
 158                 pr_err("Could not create device class for user accessible files (err %d)\n",
 159                        -ret);
 160                 class_destroy(class);
 161                 class = NULL;
 162                 user_class = NULL;
 163                 unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 164                 goto done;
 165         }
 166         user_class->devnode = hfi1_user_devnode;
 167
 168 done:
 169         return ret;
 170 }
 171
 172 void dev_cleanup(void)
 173 {
 174         class_destroy(class);
 175         class = NULL;
 176
 177         class_destroy(user_class);
 178         user_class = NULL;
 179
 180         unregister_chrdev_region(hfi1_dev, HFI1_NMINORS);
 181 }