NetBSD/sys/arch/atari/dev/nvram.c

212 lines
5.2 KiB
C

/* $NetBSD: nvram.c,v 1.6 1996/12/20 12:49:44 leo Exp $ */
/*
* Copyright (c) 1995 Leo Weppelman.
* 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 Leo Weppelman.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* 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.
*/
/*
* Nvram driver
*/
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <sys/uio.h>
#include <machine/iomap.h>
#include <machine/cpu.h>
#include <atari/dev/clockreg.h>
#include <atari/dev/nvramvar.h>
#include "nvr.h"
#define MC_NVRAM_CSUM (MC_NVRAM_START + MC_NVRAM_SIZE - 2)
#if NNVR > 0
static void nvram_set_csum __P((u_char csum));
static int nvram_csum_valid __P((u_char csum));
static u_char nvram_csum __P((void));
/*
* Auto config stuff....
*/
static void nvr_attach __P((struct device *, struct device *, void *));
static int nvr_match __P((struct device *, struct cfdata *, void *));
struct cfattach nvr_ca = {
sizeof(struct nvr_softc), nvr_match, nvr_attach
};
struct cfdriver nvr_cd = {
NULL, "nvr", DV_DULL, NULL, 0
};
/*ARGSUSED*/
static int
nvr_match(pdp, cfp, auxp)
struct device *pdp;
struct cfdata *cfp;
void *auxp;
{
if (!strcmp((char *)auxp, "nvr"))
return (1);
return (0);
}
/*ARGSUSED*/
static void
nvr_attach(pdp, dp, auxp)
struct device *pdp, *dp;
void *auxp;
{
struct nvr_softc *nvr_soft;
int nreg;
/*
* Check the validity of the NVram contents
*/
if (!nvram_csum_valid(nvram_csum())) {
printf(": Invalid checksum - re-initialized");
for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++)
mc146818_write(RTC, nreg, 0);
nvram_set_csum(nvram_csum());
}
nvr_soft = nvr_cd.cd_devs[0];
nvr_soft->nvr_flags = NVR_CONFIGURED;
printf("\n");
}
/*
* End of auto config stuff....
*/
#endif /* NNVR > 0 */
/*
* Kernel internal interface
*/
int
nvr_get_byte(byteno)
int byteno;
{
#if NNVR > 0
struct nvr_softc *nvr_soft;
nvr_soft = nvr_cd.cd_devs[0];
if (!(nvr_soft->nvr_flags & NVR_CONFIGURED))
return(NVR_INVALID);
return (mc146818_read(RTC, byteno + MC_NVRAM_START) & 0xff);
#else
return(NVR_INVALID);
#endif /* NNVR > 0 */
}
#if NNVR > 0
int
nvram_uio(uio)
struct uio *uio;
{
int i;
off_t offset;
int nleft;
u_char buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1];
u_char *p;
struct nvr_softc *nvr_soft;
nvr_soft = nvr_cd.cd_devs[0];
if (!(nvr_soft->nvr_flags & NVR_CONFIGURED))
return ENXIO;
#ifdef NV_DEBUG
printf("Request to transfer %d bytes offset: %d, %s nvram\n",
(long)uio->uio_resid, (long)uio->uio_offset,
(uio->uio_rw == UIO_READ) ? "from" : "to");
#endif /* NV_DEBUG */
offset = uio->uio_offset + MC_NVRAM_START;
nleft = uio->uio_resid;
if (offset + nleft >= MC_NVRAM_CSUM) {
if (offset == MC_NVRAM_CSUM)
return (0);
nleft = MC_NVRAM_CSUM - offset;
if (nleft <= 0)
return (EINVAL);
}
#ifdef NV_DEBUG
printf("Translated: offset = %d, bytes: %d\n", (long)offset, nleft);
#endif /* NV_DEBUG */
if (uio->uio_rw == UIO_READ) {
for (i = 0, p = buf; i < nleft; i++, p++)
*p = mc146818_read(RTC, offset + i);
}
if ((i = uiomove(buf, nleft, uio)) != 0)
return (i);
if (uio->uio_rw == UIO_WRITE) {
for (i = 0, p = buf; i < nleft; i++, p++)
mc146818_write(RTC, offset + i, *p);
nvram_set_csum(nvram_csum());
}
return(0);
}
static u_char
nvram_csum()
{
u_char csum;
int nreg;
for (csum = 0, nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM; nreg++)
csum += mc146818_read(RTC, nreg);
return(csum);
}
static int
nvram_csum_valid(csum)
u_char csum;
{
if (((~csum & 0xff) != mc146818_read(RTC, MC_NVRAM_CSUM))
|| (csum != mc146818_read(RTC, MC_NVRAM_CSUM + 1)))
return 0;
return 1;
}
static void
nvram_set_csum(csum)
u_char csum;
{
mc146818_write(RTC, MC_NVRAM_CSUM, ~csum);
mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum);
}
#endif /* NNVR > 0 */