xref: /freebsd/share/examples/kld/cdev/module/cdev.c (revision 7a19b7ed7628d63bb08c8dbd06a5bdb4ab03a96d)
1 /* 08 Nov 1998*/
2 /*
3  * cdev.c
4  *
5  * 08 Nov 1998	Rajesh Vaidheeswarran
6  *
7  * Copyright (c) 1998 Rajesh Vaidheeswarran
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by Rajesh Vaidheeswarran.
21  * 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote
22  *    products derived from this software without specific prior written
23  *    permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``AS IS'' AND ANY
26  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE RAJESH VAIDHEESWARRAN BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37   * Copyright (c) 1993 Terrence R. Lambert.
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. All advertising materials mentioning features or use of this software
49  *    must display the following acknowledgement:
50  *      This product includes software developed by Terrence R. Lambert.
51  * 4. The name Terrence R. Lambert may not be used to endorse or promote
52  *    products derived from this software without specific prior written
53  *    permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY
56  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  */
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/ioccom.h>
71 #include "cdev.h"
72 
73 /*
74  * This is the actual code for the system call... it can't be static because
75  * it is exported to another part of the module... the only place it needs
76  * to be referenced is the sysent we are interested in.
77  *
78  * To write your own system call using this as a template, you could strip
79  * out this code and use the rest as a prototype module, changing only the
80  * function names and the number of arguments to the call in the module
81  * specific "sysent".
82  *
83  * You would have to use the "-R" option of "ld" to ensure a linkable file
84  * if you were to do this, since you would need to combine multiple ".o"
85  * files into a single ".o" file for use by "modload".
86  */
87 
88 #define CDEV_IOCTL1         _IOR('C', 1, u_int)
89 
90 int
91 mydev_open(dev_t dev, int flag, int otyp, struct proc *procp)
92 {
93     printf("mydev_open: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
94 	   dev, flag, otyp, procp);
95     return (0);
96 }
97 
98 int
99 mydev_close(dev_t dev, int flag, int otyp, struct proc *procp)
100 {
101     printf("mydev_close: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
102 	      dev, flag, otyp, procp);
103     return (0);
104 }
105 
106 int
107 mydev_ioctl(dev_t dev, u_long cmd, caddr_t arg, int mode, struct proc *procp)
108 {
109     int error = 0;
110 
111     printf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x procp=%p\n",
112 	   dev, cmd, arg, mode, procp);
113 
114     switch(cmd) {
115     case CDEV_IOCTL1:
116 	printf("you called mydev_ioctl CDEV_IOCTL1\n");
117 	break;
118     default:
119 	printf("No such ioctl for me!\n");
120 	error = EINVAL;
121 	break;
122     }
123     return error;
124 }
125