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/*  This file is part of the program psim.

    Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

    */

#ifndef _HW_NVRAM_C_

#define _HW_NVRAM_C_

#ifndef STATIC_INLINE_HW_NVRAM

#define STATIC_INLINE_HW_NVRAM STATIC_INLINE

#endif

#include "device_table.h"

#ifdef HAVE_TIME_H

#include <time.h>

#endif

#ifdef HAVE_STRING_H

#include <string.h>

#else

#ifdef HAVE_STRINGS_H

#include <strings.h>

#endif

#endif

/* DEVICE

   nvram - non-volatile memory with clock

   DESCRIPTION

   This device implements a small byte addressable non-volatile

   memory.  The top 8 bytes of this memory include a real-time clock.

   PROPERTIES

   reg = <address> <size> (required)

   Specify the address/size of this device within its parents address

   space.

   timezone = <integer> (optional)

   Adjustment to the hosts current GMT (in seconds) that should be

   applied when updating the NVRAM's clock.  If no timezone is

   specified, zero (GMT or UCT) is assumed.

   */

typedef struct _hw_nvram_device {

  unsigned8 *memory;

  unsigned sizeof_memory;

#ifdef HAVE_TIME_H

  time_t host_time;

#else

  long host_time;

#endif

  unsigned timezone;

  /* useful */

  unsigned addr_year;

  unsigned addr_month;

  unsigned addr_date;

  unsigned addr_day;

  unsigned addr_hour;

  unsigned addr_minutes;

  unsigned addr_seconds;

  unsigned addr_control;

} hw_nvram_device;

static void *

hw_nvram_create(const char *name,

                const device_unit *unit_address,

                const char *args)

{

  hw_nvram_device *nvram = ZALLOC(hw_nvram_device);

  return nvram;

}

typedef struct _hw_nvram_reg_spec {

  unsigned32 base;

  unsigned32 size;

} hw_nvram_reg_spec;

static void

hw_nvram_init_address(device *me)

{

  hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);

  /* use the generic init code to attach this device to its parent bus */

  generic_device_init_address(me);

  /* find the first non zero reg property and use that as the device

     size */

  if (nvram->sizeof_memory == 0) {

    reg_property_spec reg;

    int reg_nr;

    for (reg_nr = 0;

         device_find_reg_array_property(me, "reg", reg_nr, &reg);

         reg_nr++) {

      unsigned attach_size;

      if (device_size_to_attach_size(device_parent(me),

                                     &reg.size, &attach_size,

                                     me)) {

        nvram->sizeof_memory = attach_size;

        break;

      }

    }

    if (nvram->sizeof_memory == 0)

      device_error(me, "reg property must contain a non-zero phys-addr:size tupple");

    if (nvram->sizeof_memory < 8)

      device_error(me, "NVRAM must be at least 8 bytes in size");

  }

  /* initialize the hw_nvram */

  if (nvram->memory == NULL) {

    nvram->memory = zalloc(nvram->sizeof_memory);

  }

  else

    memset(nvram->memory, 0, nvram->sizeof_memory);

  if (device_find_property(me, "timezone") == NULL)

    nvram->timezone = 0;

  else

    nvram->timezone = device_find_integer_property(me, "timezone");

  nvram->addr_year = nvram->sizeof_memory - 1;

  nvram->addr_month = nvram->sizeof_memory - 2;

  nvram->addr_date = nvram->sizeof_memory - 3;

  nvram->addr_day = nvram->sizeof_memory - 4;

  nvram->addr_hour = nvram->sizeof_memory - 5;

  nvram->addr_minutes = nvram->sizeof_memory - 6;

  nvram->addr_seconds = nvram->sizeof_memory - 7;

  nvram->addr_control = nvram->sizeof_memory - 8;

}

static int

hw_nvram_bcd(int val)

{

  val = val % 100;

  if (val < 0)

    val += 100;

  return ((val / 10) << 4) + (val % 10);

}

/* If reached an update interval and allowed, update the clock within

   the hw_nvram.  While this function could be implemented using events

   it isn't on the assumption that the HW_NVRAM will hardly ever be

   referenced and hence there is little need in keeping the clock

   continually up-to-date */

static void

hw_nvram_update_clock(hw_nvram_device *nvram,

                      cpu *processor)

{

#ifdef HAVE_TIME_H

  if (!(nvram->memory[nvram->addr_control] & 0xc0)) {

    time_t host_time = time(NULL);

    if (nvram->host_time != host_time) {

      time_t nvtime = host_time + nvram->timezone;

      struct tm *clock = gmtime(&nvtime);

      nvram->host_time = host_time;

      nvram->memory[nvram->addr_year] = hw_nvram_bcd(clock->tm_year);

      nvram->memory[nvram->addr_month] = hw_nvram_bcd(clock->tm_mon + 1);

      nvram->memory[nvram->addr_date] = hw_nvram_bcd(clock->tm_mday);

      nvram->memory[nvram->addr_day] = hw_nvram_bcd(clock->tm_wday + 1);

      nvram->memory[nvram->addr_hour] = hw_nvram_bcd(clock->tm_hour);

      nvram->memory[nvram->addr_minutes] = hw_nvram_bcd(clock->tm_min);

      nvram->memory[nvram->addr_seconds] = hw_nvram_bcd(clock->tm_sec);

    }

  }

#else

  error("fixme - where do I find out GMT\n");

#endif

}

static void

hw_nvram_set_clock(hw_nvram_device *nvram, cpu *processor)

{

  error ("fixme - how do I set the localtime\n");

}

static unsigned

hw_nvram_io_read_buffer(device *me,

                        void *dest,

                        int space,

                        unsigned_word addr,

                        unsigned nr_bytes,

                        cpu *processor,

                        unsigned_word cia)

{

  int i;

  hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);

  for (i = 0; i < nr_bytes; i++) {

    unsigned address = (addr + i) % nvram->sizeof_memory;

    unsigned8 data = nvram->memory[address];

    hw_nvram_update_clock(nvram, processor);

    ((unsigned8*)dest)[i] = data;

  }

  return nr_bytes;

}

static unsigned

hw_nvram_io_write_buffer(device *me,

                         const void *source,

                         int space,

                         unsigned_word addr,

                         unsigned nr_bytes,

                         cpu *processor,

                         unsigned_word cia)

{

  int i;

  hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);

  for (i = 0; i < nr_bytes; i++) {

    unsigned address = (addr + i) % nvram->sizeof_memory;

    unsigned8 data = ((unsigned8*)source)[i];

    if (address == nvram->addr_control

        && (data & 0x80) == 0

        && (nvram->memory[address] & 0x80) == 0x80)

      hw_nvram_set_clock(nvram, processor);

    else

      hw_nvram_update_clock(nvram, processor);

    nvram->memory[address] = data;

  }

  return nr_bytes;

}

static device_callbacks const hw_nvram_callbacks = {

  { hw_nvram_init_address, },

  { NULL, }, /* address */

  { hw_nvram_io_read_buffer, hw_nvram_io_write_buffer }, /* IO */

};

const device_descriptor hw_nvram_device_descriptor[] = {

  { "nvram", hw_nvram_create, &hw_nvram_callbacks },

  { NULL },

};

#endif /* _HW_NVRAM_C_ */