sim/ppc/hw_nvram.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19     */
  20
  21
  22 #ifndef _HW_NVRAM_C_
  23 #define _HW_NVRAM_C_
  24
  25 #ifndef STATIC_INLINE_HW_NVRAM
  26 #define STATIC_INLINE_HW_NVRAM STATIC_INLINE
  27 #endif
  28
  29 #include "device_table.h"
  30
  31 #ifdef HAVE_TIME_H
  32 #include <time.h>
  33 #endif
  34
  35 #ifdef HAVE_STRING_H
  36 #include <string.h>
  37 #else
  38 #ifdef HAVE_STRINGS_H
  39 #include <strings.h>
  40 #endif
  41 #endif
  42
  43 /* NVRAM - non-volatile memory with optional clock.
  44
  45    Description:
  46
  47    This device implements a small byte addressable non-volatile memory
  48    component.  The component may include an optional real-time clock
  49    at its upper addresses.
  50
  51    Properties:
  52
  53    reg = <address> <size>.  Determine where the device lives in the
  54    parents address space.
  55
  56    timezone = <integer>.  Adjustment to current host's GMT (in secons)
  57    that should be applied when updating the NVRAM's clock. */
  58
  59 typedef struct _hw_nvram_device {
  60   unsigned8 *memory;
  61   unsigned sizeof_memory;
  62 #ifdef HAVE_TIME_H
  63   time_t host_time;
  64 #else
  65   long host_time;
  66 #endif
  67   unsigned timezone;
  68   /* useful */
  69   unsigned addr_year;
  70   unsigned addr_month;
  71   unsigned addr_date;
  72   unsigned addr_day;
  73   unsigned addr_hour;
  74   unsigned addr_minutes;
  75   unsigned addr_seconds;
  76   unsigned addr_control;
  77 } hw_nvram_device;
  78
  79 static void *
  80 hw_nvram_create(const char *name,
  81                 const device_unit *unit_address,
  82                 const char *args,
  83                 device *parent)
  84 {
  85   hw_nvram_device *hw_nvram = ZALLOC(hw_nvram_device);
  86   return hw_nvram;
  87 }
  88
  89 typedef struct _hw_nvram_reg_spec {
  90   unsigned32 base;
  91   unsigned32 size;
  92 } hw_nvram_reg_spec;
  93
  94 static void
  95 hw_nvram_init_address(device *me)
  96 {
  97   hw_nvram_device *hw_nvram = (hw_nvram_device*)device_data(me);
  98   const device_property *reg = device_find_array_property(me, "reg");
  99   const hw_nvram_reg_spec *spec = reg->array;
 100   int nr_entries = reg->sizeof_array / sizeof(*spec);
 101
 102   if ((reg->sizeof_array % sizeof(*spec)) != 0)
 103     error("devices/%s reg property of incorrect size\n", device_name(me));
 104   if (nr_entries > 1)
 105     error("devices/%s reg property contains multiple specs\n",
 106           device_name(me));
 107
 108   /* initialize the hw_nvram */
 109   if (hw_nvram->memory == NULL) {
 110     hw_nvram->sizeof_memory = BE2H_4(spec->size);
 111     hw_nvram->memory = zalloc(hw_nvram->sizeof_memory);
 112   }
 113   else
 114     memset(hw_nvram->memory, hw_nvram->sizeof_memory, 0);
 115
 116   hw_nvram->timezone = device_find_integer_property(me, "timezone");
 117
 118   hw_nvram->addr_year = hw_nvram->sizeof_memory - 1;
 119   hw_nvram->addr_month = hw_nvram->sizeof_memory - 2;
 120   hw_nvram->addr_date = hw_nvram->sizeof_memory - 3;
 121   hw_nvram->addr_day = hw_nvram->sizeof_memory - 4;
 122   hw_nvram->addr_hour = hw_nvram->sizeof_memory - 5;
 123   hw_nvram->addr_minutes = hw_nvram->sizeof_memory - 6;
 124   hw_nvram->addr_seconds = hw_nvram->sizeof_memory - 7;
 125   hw_nvram->addr_control = hw_nvram->sizeof_memory - 8;
 126
 127   device_attach_address(device_parent(me),
 128                         device_name(me),
 129                         attach_callback,
 130                         0 /*address space*/,
 131                         BE2H_4(spec->base),
 132                         hw_nvram->sizeof_memory,
 133                         access_read_write_exec,
 134                         me);
 135 }
 136
 137 static int
 138 hw_nvram_bcd(int val)
 139 {
 140   return ((val / 10) << 4) + (val % 10);
 141 }
 142
 143 /* If reached an update interval and allowed, update the clock within
 144    the hw_nvram.  While this function could be implemented using events
 145    it isn't on the assumption that the HW_NVRAM will hardly ever be
 146    referenced and hence there is little need in keeping the clock
 147    continually up-to-date */
 148 static void
 149 hw_nvram_update_clock(hw_nvram_device *hw_nvram, cpu *processor)
 150 {
 151 #ifdef HAVE_TIME_H
 152   if (!(hw_nvram->memory[hw_nvram->addr_control] & 0xc0)) {
 153     time_t host_time = time(NULL);
 154     if (hw_nvram->host_time != host_time) {
 155       time_t nvtime = hw_nvram->host_time + hw_nvram->timezone;
 156       struct tm *clock = gmtime(&nvtime);
 157       hw_nvram->host_time = host_time;
 158       hw_nvram->memory[hw_nvram->addr_year] = hw_nvram_bcd(clock->tm_year);
 159       hw_nvram->memory[hw_nvram->addr_month] = hw_nvram_bcd(clock->tm_mon + 1);
 160       hw_nvram->memory[hw_nvram->addr_date] = hw_nvram_bcd(clock->tm_mday);
 161       hw_nvram->memory[hw_nvram->addr_day] = hw_nvram_bcd(clock->tm_wday + 1);
 162       hw_nvram->memory[hw_nvram->addr_hour] = hw_nvram_bcd(clock->tm_hour);
 163       hw_nvram->memory[hw_nvram->addr_minutes] = hw_nvram_bcd(clock->tm_min);
 164       hw_nvram->memory[hw_nvram->addr_seconds] = hw_nvram_bcd(clock->tm_sec);
 165     }
 166   }
 167 #else
 168   error("fixme - where do I find out GMT\n");
 169 #endif
 170 }
 171
 172 static void
 173 hw_nvram_set_clock(hw_nvram_device *hw_nvram, cpu *processor)
 174 {
 175   error ("fixme - how do I set the localtime\n");
 176 }
 177
 178 static unsigned
 179 hw_nvram_io_read_buffer(device *me,
 180                         void *dest,
 181                         int space,
 182                         unsigned_word addr,
 183                         unsigned nr_bytes,
 184                         cpu *processor,
 185                         unsigned_word cia)
 186 {
 187   int i;
 188   hw_nvram_device *hw_nvram = (hw_nvram_device*)device_data(me);
 189   for (i = 0; i < nr_bytes; i++) {
 190     unsigned address = (addr + i) % hw_nvram->sizeof_memory;
 191     unsigned8 data = hw_nvram->memory[address];
 192     hw_nvram_update_clock(hw_nvram, processor);
 193     ((unsigned8*)dest)[i] = data;
 194   }
 195   return nr_bytes;
 196 }
 197
 198 static unsigned
 199 hw_nvram_io_write_buffer(device *me,
 200                          const void *source,
 201                          int space,
 202                          unsigned_word addr,
 203                          unsigned nr_bytes,
 204                          cpu *processor,
 205                          unsigned_word cia)
 206 {
 207   int i;
 208   hw_nvram_device *hw_nvram = (hw_nvram_device*)device_data(me);
 209   for (i = 0; i < nr_bytes; i++) {
 210     unsigned address = (addr + i) % hw_nvram->sizeof_memory;
 211     unsigned8 data = ((unsigned8*)source)[i];
 212     if (address == hw_nvram->addr_control
 213         && (data & 0x80) == 0
 214         && (hw_nvram->memory[address] & 0x80) == 0x80)
 215       hw_nvram_set_clock(hw_nvram, processor);
 216     else
 217       hw_nvram_update_clock(hw_nvram, processor);
 218     hw_nvram->memory[address] = data;
 219   }
 220   return nr_bytes;
 221 }
 222
 223 static device_callbacks const hw_nvram_callbacks = {
 224   { hw_nvram_init_address, },
 225   { NULL, }, /* address */
 226   { hw_nvram_io_read_buffer, hw_nvram_io_write_buffer }, /* IO */
 227 };
 228
 229 const device_descriptor hw_nvram_device_descriptor[] = {
 230   { "nvram", hw_nvram_create, &hw_nvram_callbacks },
 231   { NULL },
 232 };
 233
 234 #endif /* _HW_NVRAM_C_ */