sim/ppc/hw_eeprom.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_EEPROM_C_
  23 #define _HW_EEPROM_C_
  24
  25 #ifndef STATIC_INLINE_HW_EEPROM
  26 #define STATIC_INLINE_HW_EEPROM STATIC_INLINE
  27 #endif
  28
  29 #include "device_table.h"
  30
  31 #ifdef HAVE_STRING_H
  32 #include <string.h>
  33 #else
  34 #ifdef HAVE_STRINGS_H
  35 #include <strings.h>
  36 #endif
  37 #endif
  38
  39 /* EEPROM - electricaly erasable programable memory
  40
  41    Description:
  42
  43    This device implements a small byte addressable EEPROM.
  44    Programming is performed using the same write sequences as used by
  45    modern EEPROM components.  Writes occure in real time, the device
  46    returning a progress value until the programing has been completed.
  47
  48    Properties:
  49
  50    reg = <address> <size>.  Determine where the device lives in the
  51    parents address space.
  52
  53    nr-sectors = <integer>.  When erasing an entire sector is cleared
  54    at a time.  This specifies the number of sectors in the EEPROM
  55    component.
  56
  57    byte-write-delay = <integer>.  Number of clock ticks before the
  58    programming of a single byte completes.
  59
  60    sector-start-delay = <integer>.  When erasing sectors, the number
  61    of clock ticks after the sector has been specified and the actual
  62    erase process commences.
  63
  64    erase-delay = <intger>.  Number of clock ticks before an erase
  65    program completes. */
  66
  67 typedef enum {
  68   read_reset,
  69   write_nr_2,
  70   write_nr_3,
  71   write_nr_4,
  72   write_nr_5,
  73   write_nr_6,
  74   byte_program,
  75   byte_programming,
  76   chip_erase, chip_erasing,
  77   sector_erase, sector_erasing,
  78   sector_erase_suspend,
  79   sector_erase_resume,
  80 } eeprom_states;
  81
  82 typedef struct _eeprom_device {
  83   unsigned8 *memory;
  84   unsigned sizeof_memory;
  85   unsigned sector_size;
  86   unsigned nr_sectors;
  87   unsigned byte_write_delay;
  88   unsigned sector_start_delay;
  89   unsigned erase_delay;
  90   signed64 programme_start_time;
  91   unsigned program_byte_address;
  92   eeprom_states state;
  93 } eeprom_device;
  94
  95 static void *
  96 eeprom_create(const char *name,
  97              const device_unit *unit_address,
  98              const char *args,
  99              device *parent)
 100 {
 101   eeprom_device *eeprom = ZALLOC(eeprom_device);
 102   return eeprom;
 103 }
 104
 105 typedef struct _eeprom_reg_spec {
 106   unsigned32 base;
 107   unsigned32 size;
 108 } eeprom_reg_spec;
 109
 110 static void
 111 eeprom_init_address(device *me,
 112                    psim *system)
 113 {
 114   eeprom_device *eeprom = (eeprom_device*)device_data(me);
 115   const device_property *reg = device_find_array_property(me, "reg");
 116   const eeprom_reg_spec *spec = reg->array;
 117   int nr_entries = reg->sizeof_array / sizeof(*spec);
 118
 119   if ((reg->sizeof_array % sizeof(*spec)) != 0)
 120     error("devices/%s reg property of incorrect size\n", device_name(me));
 121   if (nr_entries > 1)
 122     error("devices/%s reg property contains multiple specs\n",
 123           device_name(me));
 124
 125   /* initialize the eeprom */
 126   if (eeprom->memory == NULL) {
 127     eeprom->sizeof_memory = BE2H_4(spec->size);
 128     eeprom->memory = zalloc(eeprom->sizeof_memory);
 129   }
 130   else
 131     memset(eeprom->memory, eeprom->sizeof_memory, 0);
 132
 133   /* figure out the sectors in the eeprom */
 134   eeprom->nr_sectors = device_find_integer_property(me, "nr-sectors");
 135   eeprom->sector_size = eeprom->sizeof_memory / eeprom->nr_sectors;
 136   if (eeprom->sector_size * eeprom->nr_sectors != eeprom->sizeof_memory)
 137     error("device/%s nr-sectors does not evenly divide eeprom\n",
 138           device_name(me));
 139
 140   /* timing */
 141   eeprom->byte_write_delay = device_find_integer_property(me, "byte-write-delay");
 142   eeprom->sector_start_delay = device_find_integer_property(me, "sector-start-delay");
 143   eeprom->erase_delay = device_find_integer_property(me, "erase-delay");
 144
 145   device_attach_address(device_parent(me),
 146                         device_name(me),
 147                         attach_callback,
 148                         0 /*address space*/,
 149                         BE2H_4(spec->base),
 150                         eeprom->sizeof_memory,
 151                         access_read_write_exec,
 152                         me);
 153 }
 154
 155
 156 static unsigned
 157 eeprom_io_read_buffer(device *me,
 158                       void *dest,
 159                       int space,
 160                       unsigned_word addr,
 161                       unsigned nr_bytes,
 162                       cpu *processor,
 163                       unsigned_word cia)
 164 {
 165   eeprom_device *eeprom = (eeprom_device*)device_data(me);
 166   int i;
 167   for (i = 0; i < nr_bytes; i++) {
 168     unsigned_word address = (addr + nr_bytes) % eeprom->sizeof_memory;
 169     eeprom->memory[address] = eeprom_io_read_byte(address);
 170   }
 171   return nr_bytes;
 172 }
 173
 174 static void
 175 eeprom_io_write_byte()
 176 {
 177   switch (state) {
 178   case read_reset:
 179     if (address == 0x5555 && data = 0xaa)
 180       state = first_write;
 181     else
 182       state = read_reset;
 183     break;
 184   case first_write:
 185     if (address == 0x2aaa && data == 0x55)
 186       state = second_write;
 187     else
 188       state = read_reset; /* issue warning */
 189     break;
 190   case second_write:
 191     if (address == 0x5555 && data == 0xf0)
 192       state = read_reset;
 193     else if (address == 0x5555 && data == 0x90)
 194       state = auto_select;
 195     else if (address == 0x5555 && data == 0xa0)
 196       state = byte_program;
 197     else if (address == 0x5555 && data == 0x80)
 198       state = third_write;
 199     else
 200       state = read_reset;
 201     break;
 202   case fourth_write:
 203     if (address == 0x5555 && data == 0xaa)
 204       state = fith_write;
 205     else
 206       state = read_reset;
 207     break;
 208   case fith_write:
 209     if (address == 0x2aaa && data == 0x55)
 210       state = sixth_write;
 211     else
 212       state = read_reset;
 213     break;
 214   case sixth_write:
 215     if (address == 0x5555 && data == 0x10)
 216       state = chip_erase;
 217     else
 218       sector_erase();
 219     break;
 220   case auto_select:
 221     if (data == 0xf0)
 222       state = read_reset;
 223     else if (address == 0x5555 && data == 0xaa)
 224       state = second_write;
 225     else
 226       state = read_reset; /* issue warning */
 227     break;
 228   case sector_erase:
 229     if (data == 0xb0)
 230       state = sector_erase_suspend;
 231     else
 232       state = sector_erase; /* ignore */
 233     break;
 234   case sector_erase_suspend:
 235     if (data == 0x30)
 236       state = sector_erase;
 237     else
 238       state = sector_erase_suspend; /* ignore */
 239     break;
 240   case byte_program:
 241     /* perform the byte program */
 242     program_address = address;
 243     program_start = some_time();
 244     toggle = 0;
 245     /* but only make things `0' and never 1 */
 246     byte[address] = data;
 247     state = byte_programming;
 248     break;
 249   case byte_programming:
 250     if (finished)
 251       state = read_reset;
 252     else
 253       state = byte_programming;
 254     break;
 255   }
 256 }
 257
 258 static unsigned
 259 eeprom_io_write_buffer(device *me,
 260                        const void *source,
 261                        int space,
 262                        unsigned_word addr,
 263                        unsigned nr_bytes,
 264                        cpu *processor,
 265                        unsigned_word cia)
 266 {
 267   eeprom_device *eeprom = (eeprom_device*)device_data(me);
 268   int i;
 269   for (i = 0; i < nr_bytes; i++) {
 270     unsigned_word address = (addr + nr_bytes) % eeprom->sizeof_memory;
 271     eeprom_io_read_byte(address, eeprom->memory[address]);
 272   }
 273   return nr_bytes;
 274 }
 275
 276
 277
 278 static device_callbacks const eeprom_callbacks = {
 279   { eeprom_init_address, },
 280   { NULL, }, /* address */
 281   { eeprom_io_read_buffer, eeprom_io_write_buffer }, /* IO */
 282 };
 283
 284 const device_descriptor eeprom_device_descriptor[] = {
 285   { "eeprom", eeprom_create, &eeprom_callbacks },
 286   { NULL },
 287 };
 288
 289 #endif /* _HW_EEPROM_C_ */