xref: /freebsd/share/examples/kld/cdev/module/cdevmod.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 /* 08 Nov 1998*/
2 /*
3  * cdevmod.c - a sample kld module implementing a character device driver.
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/kernel.h>
71 #include <sys/module.h>
72 #include <sys/conf.h>
73 
74 #include "cdev.h"
75 
76 #define CDEV_MAJOR 32
77 
78 static struct cdevsw my_devsw = {
79 	/* open */	mydev_open,
80 	/* close */	mydev_close,
81 	/* read */	noread,
82 	/* write */	nowrite,
83 	/* ioctl */	mydev_ioctl,
84 	/* stop */	nostop,
85 	/* reset */	noreset,
86 	/* devtotty */	nodevtotty,
87 	/* poll */	nopoll,
88 	/* mmap */	nommap,
89 	/* strategy */	nostrategy,
90 	/* name */	"cdev",
91 	/* parms */	noparms,
92 	/* maj */	CDEV_MAJOR,
93 	/* dump */	nodump,
94 	/* psize */	nopsize,
95 	/* flags */	D_TTY,
96 	/* maxio */	0,
97 	/* bmaj */	-1
98 };
99 
100 /*
101  * This function is called each time the module is loaded or unloaded.
102  * Since we are a miscellaneous module, we have to provide whatever
103  * code is necessary to patch ourselves into the area we are being
104  * loaded to change.
105  *
106  * The stat information is basically common to all modules, so there
107  * is no real issue involved with stat; we will leave it lkm_nullcmd(),
108  * since we don't have to do anything about it.
109  */
110 
111 static int
112 cdev_load(module_t mod, int cmd, void *arg)
113 {
114     int  err = 0;
115 
116     switch (cmd) {
117     case MOD_LOAD:
118 
119 	/* Do any initialization that you should do with the kernel */
120 
121 	/* if we make it to here, print copyright on console*/
122 	printf("\nSample Loaded kld character device driver\n");
123 	printf("Copyright (c) 1998\n");
124 	printf("Rajesh Vaidheeswarran\n");
125 	printf("All rights reserved\n");
126 	break;		/* Success*/
127 
128     case MOD_UNLOAD:
129 	printf("Unloaded kld character device driver\n");
130 	break;		/* Success*/
131 
132     default:	/* we only understand load/unload*/
133 	err = EINVAL;
134 	break;
135     }
136 
137     return(err);
138 }
139 
140 /* Now declare the module to the system */
141 
142 DEV_MODULE(cdev, CDEV_MAJOR, -1, my_devsw, cdev_load, 0);
143