sim/bfin/dv-bfin_wdog.c

   1 /* Blackfin Watchdog (WDOG) model.
   2
   3    Copyright (C) 2010-2013 Free Software Foundation, Inc.
   4    Contributed by Analog Devices, Inc.
   5
   6    This file is part of simulators.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22
  23 #include "sim-main.h"
  24 #include "dv-sockser.h"
  25 #include "devices.h"
  26 #include "dv-bfin_wdog.h"
  27
  28 /* XXX: Should we bother emulating the TX/RX FIFOs ?  */
  29
  30 struct bfin_wdog
  31 {
  32   bu32 base;
  33
  34   /* Order after here is important -- matches hardware MMR layout.  */
  35   bu16 BFIN_MMR_16(ctl);
  36   bu32 cnt, stat;
  37 };
  38 #define mmr_base()      offsetof(struct bfin_wdog, ctl)
  39 #define mmr_offset(mmr) (offsetof(struct bfin_wdog, mmr) - mmr_base())
  40
  41 static const char * const mmr_names[] =
  42 {
  43   "WDOG_CTL", "WDOG_CNT", "WDOG_STAT",
  44 };
  45 #define mmr_name(off) mmr_names[(off) / 4]
  46
  47 static bool
  48 bfin_wdog_enabled (struct bfin_wdog *wdog)
  49 {
  50   return ((wdog->ctl & WDEN) != WDDIS);
  51 }
  52
  53 static unsigned
  54 bfin_wdog_io_write_buffer (struct hw *me, const void *source,
  55                            int space, address_word addr, unsigned nr_bytes)
  56 {
  57   struct bfin_wdog *wdog = hw_data (me);
  58   bu32 mmr_off;
  59   bu32 value;
  60   bu16 *value16p;
  61   bu32 *value32p;
  62   void *valuep;
  63
  64   if (nr_bytes == 4)
  65     value = dv_load_4 (source);
  66   else
  67     value = dv_load_2 (source);
  68
  69   mmr_off = addr - wdog->base;
  70   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
  71   value16p = valuep;
  72   value32p = valuep;
  73
  74   HW_TRACE_WRITE ();
  75
  76   switch (mmr_off)
  77     {
  78     case mmr_offset(ctl):
  79       dv_w1c_2_partial (value16p, value, WDRO);
  80       /* XXX: Should enable an event here to handle timeouts.  */
  81       break;
  82
  83     case mmr_offset(cnt):
  84       /* Writes are discarded when enabeld.  */
  85       if (!bfin_wdog_enabled (wdog))
  86         {
  87           *value32p = value;
  88           /* Writes to CNT preloads the STAT.  */
  89           wdog->stat = wdog->cnt;
  90         }
  91       break;
  92
  93     case mmr_offset(stat):
  94       /* When enabled, writes to STAT reload the counter.  */
  95       if (bfin_wdog_enabled (wdog))
  96         wdog->stat = wdog->cnt;
  97       /* XXX: When disabled, are writes just ignored ?  */
  98       break;
  99     }
 100
 101   return nr_bytes;
 102 }
 103
 104 static unsigned
 105 bfin_wdog_io_read_buffer (struct hw *me, void *dest,
 106                           int space, address_word addr, unsigned nr_bytes)
 107 {
 108   struct bfin_wdog *wdog = hw_data (me);
 109   bu32 mmr_off;
 110   bu16 *value16p;
 111   bu32 *value32p;
 112   void *valuep;
 113
 114   mmr_off = addr - wdog->base;
 115   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
 116   value16p = valuep;
 117   value32p = valuep;
 118
 119   HW_TRACE_READ ();
 120
 121   switch (mmr_off)
 122     {
 123     case mmr_offset(ctl):
 124       dv_bfin_mmr_require_16 (me, addr, nr_bytes, false);
 125       dv_store_2 (dest, *value16p);
 126       break;
 127
 128     case mmr_offset(cnt):
 129     case mmr_offset(stat):
 130       dv_store_4 (dest, *value32p);
 131       break;
 132     }
 133
 134   return nr_bytes;
 135 }
 136
 137 static const struct hw_port_descriptor bfin_wdog_ports[] =
 138 {
 139   { "reset", WDEV_RESET, 0, output_port, },
 140   { "nmi",   WDEV_NMI,   0, output_port, },
 141   { "gpi",   WDEV_GPI,   0, output_port, },
 142   { NULL, 0, 0, 0, },
 143 };
 144
 145 static void
 146 bfin_wdog_port_event (struct hw *me, int my_port, struct hw *source,
 147                       int source_port, int level)
 148 {
 149   struct bfin_wdog *wdog = hw_data (me);
 150   bu16 wdev;
 151
 152   wdog->ctl |= WDRO;
 153   wdev = (wdog->ctl & WDEV);
 154   if (wdev != WDEV_NONE)
 155     hw_port_event (me, wdev, 1);
 156 }
 157
 158 static void
 159 attach_bfin_wdog_regs (struct hw *me, struct bfin_wdog *wdog)
 160 {
 161   address_word attach_address;
 162   int attach_space;
 163   unsigned attach_size;
 164   reg_property_spec reg;
 165
 166   if (hw_find_property (me, "reg") == NULL)
 167     hw_abort (me, "Missing \"reg\" property");
 168
 169   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 170     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 171
 172   hw_unit_address_to_attach_address (hw_parent (me),
 173                                      &reg.address,
 174                                      &attach_space, &attach_address, me);
 175   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 176
 177   if (attach_size != BFIN_MMR_WDOG_SIZE)
 178     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_WDOG_SIZE);
 179
 180   hw_attach_address (hw_parent (me),
 181                      0, attach_space, attach_address, attach_size, me);
 182
 183   wdog->base = attach_address;
 184 }
 185
 186 static void
 187 bfin_wdog_finish (struct hw *me)
 188 {
 189   struct bfin_wdog *wdog;
 190
 191   wdog = HW_ZALLOC (me, struct bfin_wdog);
 192
 193   set_hw_data (me, wdog);
 194   set_hw_io_read_buffer (me, bfin_wdog_io_read_buffer);
 195   set_hw_io_write_buffer (me, bfin_wdog_io_write_buffer);
 196   set_hw_ports (me, bfin_wdog_ports);
 197   set_hw_port_event (me, bfin_wdog_port_event);
 198
 199   attach_bfin_wdog_regs (me, wdog);
 200
 201   /* Initialize the Watchdog.  */
 202   wdog->ctl = WDDIS;
 203 }
 204
 205 const struct hw_descriptor dv_bfin_wdog_descriptor[] =
 206 {
 207   {"bfin_wdog", bfin_wdog_finish,},
 208   {NULL, NULL},
 209 };