/* 08 Nov 1998*/
/*
 * cdev.c
 *
 * 08 Nov 1998	Rajesh Vaidheeswarran
 *
 * Copyright (c) 1998 Rajesh Vaidheeswarran
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Rajesh Vaidheeswarran.
 * 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE RAJESH VAIDHEESWARRAN BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
  * Copyright (c) 1993 Terrence R. Lambert.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Terrence R. Lambert.
 * 4. The name Terrence R. Lambert may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *
 * $FreeBSD: src/share/examples/kld/cdev/module/cdev.c,v 1.3.2.1 2000/10/25 09:02:34 sobomax Exp $
 */
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioccom.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>

#include "cdev.h"

/*
 * This is the actual code for the system call... it can't be static because
 * it is exported to another part of the module... the only place it needs
 * to be referenced is the sysent we are interested in.
 *
 * To write your own system call using this as a template, you could strip
 * out this code and use the rest as a prototype module, changing only the
 * function names and the number of arguments to the call in the module
 * specific "sysent".
 *
 * You would have to use the "-R" option of "ld" to ensure a linkable file
 * if you were to do this, since you would need to combine multiple ".o"
 * files into a single ".o" file for use by "modload".
 */

#define CDEV_IOCTL1         _IOR('C', 1, u_int)

/* Stores string recv'd by _write() */
static char buf[512+1];
static size_t len;

int
mydev_open(struct dev_open_args *args)
{
	kprintf("mydev_open: dev_t=%d, flags=%x, type=%x\n",
	    devid_from_dev(args->a_head.a_dev), args->a_oflags,
	    args->a_devtype);
	memset(&buf, '\0', 513);
	len = 0;

	return (0);
}

int
mydev_close(struct dev_close_args *args)
{
	kprintf("mydev_close: dev_t=%d, flags=%x, type=%x\n",
	    devid_from_dev(args->a_head.a_dev), args->a_fflag,
	    args->a_devtype);

	return (0);
}

int
mydev_ioctl(struct dev_ioctl_args *args)
{
	int error = 0;

	kprintf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x\n",
	    devid_from_dev(args->a_head.a_dev), args->a_cmd, args->a_data,
	    args->a_fflag);

	switch(args->a_cmd) {
	case CDEV_IOCTL1:
		kprintf("you called mydev_ioctl CDEV_IOCTL1\n");
		break;
	default:
		kprintf("No such ioctl for me!\n");
		error = EINVAL;
		break;
	}

	return (error);
}

/*
 * mydev_write takes in a character string and saves it
 * to buf for later accessing.
 */
int
mydev_write(struct dev_write_args *args)
{
	int err = 0;

	kprintf("mydev_write: dev_t=%d, uio=%p, ioflag=%d\n",
	    devid_from_dev(args->a_head.a_dev), args->a_uio, args->a_ioflag);

	err = copyinstr(args->a_uio->uio_iov->iov_base, &buf, 512, &len);
	if (err != 0) {
		kprintf("Write to \"cdev\" failed.\n");
	}

    return (err);
}

/*
 * The mydev_read function just takes the buf that was saved 
 * via mydev_write() and returns it to userland for
 * accessing.
 */
int
mydev_read(struct dev_read_args *args)
{
	int err = 0;

	kprintf("mydev_read: dev_t=%d, uio=%p, ioflag=%d\n",
	    devid_from_dev(args->a_head.a_dev), args->a_uio, args->a_ioflag);

	if (len <= 0) {
		err = -1;
	}
	else {
		/* copy buf to userland */
		copystr(&buf, args->a_uio->uio_iov->iov_base, 513, &len);
	}

	return (err);
}
