* Copyright (C) 2003 JONE System Co., Inc.

/* $NetBSD: cmos.c,v 1.14 2023/12/20 15:00:07 thorpej Exp $ */

/*
* Copyright (C) 2003 JONE System Co., Inc.
* All right reserved.
*
* Copyright (C) 1999, 2000, 2001, 2002 JEPRO Co., Ltd.
* All right 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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) 2007 David Young. All right 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cmos.c,v 1.14 2023/12/20 15:00:07 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <sys/kauth.h>

#include <sys/bus.h>
#include <machine/intr.h>

#include <dev/isa/isareg.h>
#include <dev/isa/isavar.h>
#include <dev/ic/mc146818reg.h>
#include <i386/isa/nvram.h>

#include "ioconf.h"

#define CMOS_SUM 32
#define CMOS_BIOSSPEC 34 /* start of BIOS-specific configuration data */

#define NVRAM_SUM (MC_NVRAM_START + CMOS_SUM)
#define NVRAM_BIOSSPEC (MC_NVRAM_START + CMOS_BIOSSPEC)

#define CMOS_SIZE NVRAM_BIOSSPEC

dev_type_open(cmos_open);
dev_type_read(cmos_read);
dev_type_write(cmos_write);

static void cmos_sum(uint8_t *, int, int, int);

const struct cdevsw cmos_cdevsw = {
.d_open = cmos_open,
.d_close = nullclose,
.d_read = cmos_read,
.d_write = cmos_write,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER | D_MPSAFE
};

static kmutex_t cmos_lock;
static uint8_t cmos_buf[CMOS_SIZE];

void
cmosattach(int n)
{

mutex_init(&cmos_lock, MUTEX_DEFAULT, IPL_NONE);
}

int
cmos_open(dev_t dev, int flags, int ifmt, struct lwp *l)
{

return kauth_authorize_machdep(l->l_cred,
KAUTH_MACHDEP_NVRAM, NULL, NULL, NULL, NULL);
}

static void
cmos_fetch(void)
{
int i, s;
uint8_t *p;

p = cmos_buf;
s = splclock();
for (i = 0; i < CMOS_SIZE; i++)
*p++ = mc146818_read(NULL, i);
splx(s);
}

int
cmos_read(dev_t dev, struct uio *uio, int ioflag)
{
int error;

if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
return EINVAL;

mutex_enter(&cmos_lock);
cmos_fetch();
error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
mutex_exit(&cmos_lock);

return error;
}

int
cmos_write(dev_t dev, struct uio *uio, int ioflag)
{
int error = 0, i, s;

if (uio->uio_offset + uio->uio_resid > CMOS_SIZE)
return EINVAL;

mutex_enter(&cmos_lock);
cmos_fetch();
error = uiomove(cmos_buf + uio->uio_offset, uio->uio_resid, uio);
if (error == 0) {
cmos_sum(cmos_buf, NVRAM_DISKETTE, NVRAM_SUM, NVRAM_SUM);
s = splclock();
for (i = NVRAM_DISKETTE; i < CMOS_SIZE; i++)
mc146818_write(NULL, i, cmos_buf[i]);
splx(s);
}
mutex_exit(&cmos_lock);

return error;
}

static void
cmos_sum(uint8_t *p, int from, int to, int offset)
{
int i;
uint16_t sum;

#ifdef CMOS_DEBUG
printf("%s: from %d to %d and store %d\n", __func__, from, to, offset);
#endif

sum = 0;
for (i = from; i < to; i++)
sum += p[i];
p[offset] = sum >> 8;
p[offset + 1] = sum & 0xff;
}