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 * $FreeBSD$
69 */
70#include <sys/param.h>
71#include <sys/uio.h>
72#include <sys/proc.h>
73#include <sys/systm.h>
74#include <sys/ioccom.h>
75#include <sys/conf.h>
76
77#include "cdev.h"
78
79/*
80 * This is the actual code for the system call... it can't be static because
81 * it is exported to another part of the module... the only place it needs
82 * to be referenced is the sysent we are interested in.
83 *
84 * To write your own system call using this as a template, you could strip
85 * out this code and use the rest as a prototype module, changing only the
86 * function names and the number of arguments to the call in the module
87 * specific "sysent".
88 *
89 * You would have to use the "-R" option of "ld" to ensure a linkable file
90 * if you were to do this, since you would need to combine multiple ".o"
91 * files into a single ".o" file for use by "modload".
92 */
93
94#define CDEV_IOCTL1         _IOR('C', 1, u_int)
95
96/* Stores string recv'd by _write() */
97static char buf[512+1];
98static size_t len;
99
100int
101mydev_open(struct cdev *dev, int flag, int otyp, struct thread *td)
102{
103    struct proc *procp = td->td_proc;
104
105    printf("mydev_open: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
106	   dev2udev(dev), flag, otyp, procp);
107    memset(&buf, '\0', 513);
108    len = 0;
109    return (0);
110}
111
112int
113mydev_close(struct cdev *dev, int flag, int otyp, struct thread *td)
114{
115    struct proc *procp = td->td_proc;
116
117    printf("mydev_close: dev_t=%d, flag=%x, otyp=%x, procp=%p\n",
118	      dev2udev(dev), flag, otyp, procp);
119    return (0);
120}
121
122int
123mydev_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
124    struct thread *td)
125{
126    int error = 0;
127    struct proc *procp = td->td_proc;
128
129    printf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x procp=%p\n",
130	   dev2udev(dev), cmd, arg, mode, procp);
131
132    switch(cmd) {
133    case CDEV_IOCTL1:
134	printf("you called mydev_ioctl CDEV_IOCTL1\n");
135	break;
136    default:
137	printf("No such ioctl for me!\n");
138	error = EINVAL;
139	break;
140    }
141    return (error);
142}
143
144/*
145 * mydev_write takes in a character string and saves it
146 * to buf for later accessing.
147 */
148int
149mydev_write(struct cdev *dev, struct uio *uio, int ioflag)
150{
151    int err = 0;
152
153    printf("mydev_write: dev_t=%d, uio=%p, ioflag=%d\n",
154	dev2udev(dev), uio, ioflag);
155
156    err = copyinstr(uio->uio_iov->iov_base, &buf, 512, &len);
157    if (err != 0) {
158	printf("Write to \"cdev\" failed.\n");
159    }
160    return(err);
161}
162
163/*
164 * The mydev_read function just takes the buf that was saved
165 * via mydev_write() and returns it to userland for
166 * accessing.
167 */
168int
169mydev_read(struct cdev *dev, struct uio *uio, int ioflag)
170{
171    int err = 0;
172
173    printf("mydev_read: dev_t=%d, uio=%p, ioflag=%d\n",
174	dev2udev(dev), uio, ioflag);
175
176    if (len <= 0) {
177	err = -1;
178    } else {	/* copy buf to userland */
179	copystr(&buf, uio->uio_iov->iov_base, 513, &len);
180    }
181    return(err);
182}
183