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 3 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, see <http://www.gnu.org/licenses/>.
  17
  18     */
  19
  20
  21 #ifndef _HW_NVRAM_C_
  22 #define _HW_NVRAM_C_
  23
  24 #ifndef STATIC_INLINE_HW_NVRAM
  25 #define STATIC_INLINE_HW_NVRAM STATIC_INLINE
  26 #endif
  27
  28 #include "device_table.h"
  29
  30 #ifdef HAVE_TIME_H
  31 #include <time.h>
  32 #endif
  33
  34 #ifdef HAVE_STRING_H
  35 #include <string.h>
  36 #else
  37 #ifdef HAVE_STRINGS_H
  38 #include <strings.h>
  39 #endif
  40 #endif
  41
  42 /* DEVICE
  43
  44
  45    nvram - non-volatile memory with clock
  46
  47
  48    DESCRIPTION
  49
  50
  51    This device implements a small byte addressable non-volatile
  52    memory.  The top 8 bytes of this memory include a real-time clock.
  53
  54
  55    PROPERTIES
  56
  57
  58    reg = <address> <size> (required)
  59
  60    Specify the address/size of this device within its parents address
  61    space.
  62
  63
  64    timezone = <integer> (optional)
  65
  66    Adjustment to the hosts current GMT (in seconds) that should be
  67    applied when updating the NVRAM's clock.  If no timezone is
  68    specified, zero (GMT or UCT) is assumed.
  69
  70
  71    */
  72
  73 typedef struct _hw_nvram_device {
  74   unsigned8 *memory;
  75   unsigned sizeof_memory;
  76 #ifdef HAVE_TIME_H
  77   time_t host_time;
  78 #else
  79   long host_time;
  80 #endif
  81   unsigned timezone;
  82   /* useful */
  83   unsigned addr_year;
  84   unsigned addr_month;
  85   unsigned addr_date;
  86   unsigned addr_day;
  87   unsigned addr_hour;
  88   unsigned addr_minutes;
  89   unsigned addr_seconds;
  90   unsigned addr_control;
  91 } hw_nvram_device;
  92
  93 static void *
  94 hw_nvram_create(const char *name,
  95                 const device_unit *unit_address,
  96                 const char *args)
  97 {
  98   hw_nvram_device *nvram = ZALLOC(hw_nvram_device);
  99   return nvram;
 100 }
 101
 102 typedef struct _hw_nvram_reg_spec {
 103   unsigned32 base;
 104   unsigned32 size;
 105 } hw_nvram_reg_spec;
 106
 107 static void
 108 hw_nvram_init_address(device *me)
 109 {
 110   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 111
 112   /* use the generic init code to attach this device to its parent bus */
 113   generic_device_init_address(me);
 114
 115   /* find the first non zero reg property and use that as the device
 116      size */
 117   if (nvram->sizeof_memory == 0) {
 118     reg_property_spec reg;
 119     int reg_nr;
 120     for (reg_nr = 0;
 121          device_find_reg_array_property(me, "reg", reg_nr, &reg);
 122          reg_nr++) {
 123       unsigned attach_size;
 124       if (device_size_to_attach_size(device_parent(me),
 125                                      &reg.size, &attach_size,
 126                                      me)) {
 127         nvram->sizeof_memory = attach_size;
 128         break;
 129       }
 130     }
 131     if (nvram->sizeof_memory == 0)
 132       device_error(me, "reg property must contain a non-zero phys-addr:size tupple");
 133     if (nvram->sizeof_memory < 8)
 134       device_error(me, "NVRAM must be at least 8 bytes in size");
 135   }
 136
 137   /* initialize the hw_nvram */
 138   if (nvram->memory == NULL) {
 139     nvram->memory = zalloc(nvram->sizeof_memory);
 140   }
 141   else
 142     memset(nvram->memory, 0, nvram->sizeof_memory);
 143
 144   if (device_find_property(me, "timezone") == NULL)
 145     nvram->timezone = 0;
 146   else
 147     nvram->timezone = device_find_integer_property(me, "timezone");
 148
 149   nvram->addr_year = nvram->sizeof_memory - 1;
 150   nvram->addr_month = nvram->sizeof_memory - 2;
 151   nvram->addr_date = nvram->sizeof_memory - 3;
 152   nvram->addr_day = nvram->sizeof_memory - 4;
 153   nvram->addr_hour = nvram->sizeof_memory - 5;
 154   nvram->addr_minutes = nvram->sizeof_memory - 6;
 155   nvram->addr_seconds = nvram->sizeof_memory - 7;
 156   nvram->addr_control = nvram->sizeof_memory - 8;
 157
 158 }
 159
 160 static int
 161 hw_nvram_bcd(int val)
 162 {
 163   val = val % 100;
 164   if (val < 0)
 165     val += 100;
 166   return ((val / 10) << 4) + (val % 10);
 167 }
 168
 169
 170 /* If reached an update interval and allowed, update the clock within
 171    the hw_nvram.  While this function could be implemented using events
 172    it isn't on the assumption that the HW_NVRAM will hardly ever be
 173    referenced and hence there is little need in keeping the clock
 174    continually up-to-date */
 175
 176 static void
 177 hw_nvram_update_clock(hw_nvram_device *nvram,
 178                       cpu *processor)
 179 {
 180 #ifdef HAVE_TIME_H
 181   if (!(nvram->memory[nvram->addr_control] & 0xc0)) {
 182     time_t host_time = time(NULL);
 183     if (nvram->host_time != host_time) {
 184       time_t nvtime = host_time + nvram->timezone;
 185       struct tm *clock = gmtime(&nvtime);
 186       nvram->host_time = host_time;
 187       nvram->memory[nvram->addr_year] = hw_nvram_bcd(clock->tm_year);
 188       nvram->memory[nvram->addr_month] = hw_nvram_bcd(clock->tm_mon + 1);
 189       nvram->memory[nvram->addr_date] = hw_nvram_bcd(clock->tm_mday);
 190       nvram->memory[nvram->addr_day] = hw_nvram_bcd(clock->tm_wday + 1);
 191       nvram->memory[nvram->addr_hour] = hw_nvram_bcd(clock->tm_hour);
 192       nvram->memory[nvram->addr_minutes] = hw_nvram_bcd(clock->tm_min);
 193       nvram->memory[nvram->addr_seconds] = hw_nvram_bcd(clock->tm_sec);
 194     }
 195   }
 196 #else
 197   error("fixme - where do I find out GMT\n");
 198 #endif
 199 }
 200
 201 static void
 202 hw_nvram_set_clock(hw_nvram_device *nvram, cpu *processor)
 203 {
 204   error ("fixme - how do I set the localtime\n");
 205 }
 206
 207 static unsigned
 208 hw_nvram_io_read_buffer(device *me,
 209                         void *dest,
 210                         int space,
 211                         unsigned_word addr,
 212                         unsigned nr_bytes,
 213                         cpu *processor,
 214                         unsigned_word cia)
 215 {
 216   int i;
 217   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 218   for (i = 0; i < nr_bytes; i++) {
 219     unsigned address = (addr + i) % nvram->sizeof_memory;
 220     unsigned8 data = nvram->memory[address];
 221     hw_nvram_update_clock(nvram, processor);
 222     ((unsigned8*)dest)[i] = data;
 223   }
 224   return nr_bytes;
 225 }
 226
 227 static unsigned
 228 hw_nvram_io_write_buffer(device *me,
 229                          const void *source,
 230                          int space,
 231                          unsigned_word addr,
 232                          unsigned nr_bytes,
 233                          cpu *processor,
 234                          unsigned_word cia)
 235 {
 236   int i;
 237   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 238   for (i = 0; i < nr_bytes; i++) {
 239     unsigned address = (addr + i) % nvram->sizeof_memory;
 240     unsigned8 data = ((unsigned8*)source)[i];
 241     if (address == nvram->addr_control
 242         && (data & 0x80) == 0
 243         && (nvram->memory[address] & 0x80) == 0x80)
 244       hw_nvram_set_clock(nvram, processor);
 245     else
 246       hw_nvram_update_clock(nvram, processor);
 247     nvram->memory[address] = data;
 248   }
 249   return nr_bytes;
 250 }
 251
 252 static device_callbacks const hw_nvram_callbacks = {
 253   { hw_nvram_init_address, },
 254   { NULL, }, /* address */
 255   { hw_nvram_io_read_buffer, hw_nvram_io_write_buffer }, /* IO */
 256 };
 257
 258 const device_descriptor hw_nvram_device_descriptor[] = {
 259   { "nvram", hw_nvram_create, &hw_nvram_callbacks },
 260   { NULL },
 261 };
 262
 263 #endif /* _HW_NVRAM_C_ */