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_set_parent(cdev, 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 }
184