/*      $NetBSD: nvram.c,v 1.23 2023/01/06 10:28:28 tsutsui 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.
*
* 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nvram.c,v 1.23 2023/01/06 10:28:28 tsutsui Exp $");

#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 "ioconf.h"

#include "nvr.h"

#ifdef NVRAM_DEBUG
#define DPRINTF(a) printf a
#else
#define DPRINTF(a)
#endif

#define MC_NVRAM_CSUM   (MC_NVRAM_START + MC_NVRAM_SIZE - 2)

#if NNVR > 0
static void     nvram_set_csum(u_char csum);
static int      nvram_csum_valid(u_char csum);
static u_char   nvram_csum(void);

/*
* Auto config stuff....
*/
static void     nvr_attach(device_t, device_t, void *);
static int      nvr_match(device_t, cfdata_t, void *);

CFATTACH_DECL_NEW(nvr, sizeof(struct nvr_softc),
   nvr_match, nvr_attach, NULL, NULL);

/*ARGSUSED*/
static int
nvr_match(device_t parent, cfdata_t cf, void *aux)
{

       if (!strcmp((char *)aux, "nvr"))
               return 1;
       return 0;
}

/*ARGSUSED*/
static void
nvr_attach(device_t parent, device_t self, void *aux)
{
       struct nvr_softc *sc;
       int nreg;

       /*
        * Check the validity of the NVram contents
        */
       /* XXX: Milan's firmware seems to use different check method */
       if ((machineid & ATARI_MILAN) == 0) {
               if (!nvram_csum_valid(nvram_csum())) {
                       aprint_error(": Invalid checksum - re-initialized");
                       for (nreg = MC_NVRAM_START; nreg < MC_NVRAM_CSUM;
                           nreg++)
                               mc146818_write(RTC, nreg, 0);
                       nvram_set_csum(nvram_csum());
               }
       }
       sc = device_private(self);
       sc->sc_dev = self;
       sc->sc_flags = NVR_CONFIGURED;
       aprint_normal("\n");
}
/*
* End of auto config stuff....
*/
#endif /* NNVR > 0 */

/*
* Kernel internal interface
*/
int
nvr_get_byte(int byteno)
{
#if NNVR > 0
       struct nvr_softc *sc;

       sc = device_lookup_private(&nvr_cd, 0);
       if ((sc->sc_flags & NVR_CONFIGURED) == 0)
               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(struct uio *uio)
{
       int i;
       off_t offset;
       int nleft;
       uint8_t buf[MC_NVRAM_CSUM - MC_NVRAM_START + 1];
       uint8_t *p;
       struct nvr_softc *sc;

       sc = device_lookup_private(&nvr_cd,0);
       if ((sc->sc_flags & NVR_CONFIGURED) == 0)
               return ENXIO;

       DPRINTF(("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"));

       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;
       }
       DPRINTF(("Translated: offset = %d, bytes: %d\n", (long)offset, nleft));

       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(void)
{
       uint8_t 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(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(u_char csum)
{

       mc146818_write(RTC, MC_NVRAM_CSUM,    ~csum);
       mc146818_write(RTC, MC_NVRAM_CSUM + 1, csum);
}
#endif /* NNVR > 0 */

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.