sim/bfin/dv-bfin_wdog.c

   1 /* Blackfin Watchdog (WDOG) model.
   2
   3    Copyright (C) 2010-2011 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   "WDOG_CTL", "WDOG_CNT", "WDOG_STAT",
  43 };
  44 #define mmr_name(off) mmr_names[(off) / 4]
  45
  46 static bool
  47 bfin_wdog_enabled (struct bfin_wdog *wdog)
  48 {
  49   return ((wdog->ctl & WDEN) != WDDIS);
  50 }
  51
  52 static unsigned
  53 bfin_wdog_io_write_buffer (struct hw *me, const void *source,
  54                            int space, address_word addr, unsigned nr_bytes)
  55 {
  56   struct bfin_wdog *wdog = hw_data (me);
  57   bu32 mmr_off;
  58   bu32 value;
  59   bu16 *value16p;
  60   bu32 *value32p;
  61   void *valuep;
  62
  63   if (nr_bytes == 4)
  64     value = dv_load_4 (source);
  65   else
  66     value = dv_load_2 (source);
  67
  68   mmr_off = addr - wdog->base;
  69   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
  70   value16p = valuep;
  71   value32p = valuep;
  72
  73   HW_TRACE_WRITE ();
  74
  75   switch (mmr_off)
  76     {
  77     case mmr_offset(ctl):
  78       dv_w1c_2_partial (value16p, value, WDRO);
  79       /* XXX: Should enable an event here to handle timeouts.  */
  80       break;
  81
  82     case mmr_offset(cnt):
  83       /* Writes are discarded when enabeld.  */
  84       if (!bfin_wdog_enabled (wdog))
  85         {
  86           *value32p = value;
  87           /* Writes to CNT preloads the STAT.  */
  88           wdog->stat = wdog->cnt;
  89         }
  90       break;
  91
  92     case mmr_offset(stat):
  93       /* When enabled, writes to STAT reload the counter.  */
  94       if (bfin_wdog_enabled (wdog))
  95         wdog->stat = wdog->cnt;
  96       /* XXX: When disabled, are writes just ignored ?  */
  97       break;
  98     }
  99
 100   return nr_bytes;
 101 }
 102
 103 static unsigned
 104 bfin_wdog_io_read_buffer (struct hw *me, void *dest,
 105                           int space, address_word addr, unsigned nr_bytes)
 106 {
 107   struct bfin_wdog *wdog = hw_data (me);
 108   bu32 mmr_off;
 109   bu16 *value16p;
 110   bu32 *value32p;
 111   void *valuep;
 112
 113   mmr_off = addr - wdog->base;
 114   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
 115   value16p = valuep;
 116   value32p = valuep;
 117
 118   HW_TRACE_READ ();
 119
 120   switch (mmr_off)
 121     {
 122     case mmr_offset(ctl):
 123       dv_bfin_mmr_require_16 (me, addr, nr_bytes, false);
 124       dv_store_2 (dest, *value16p);
 125       break;
 126
 127     case mmr_offset(cnt):
 128     case mmr_offset(stat):
 129       dv_store_4 (dest, *value32p);
 130       break;
 131     }
 132
 133   return nr_bytes;
 134 }
 135
 136 static const struct hw_port_descriptor bfin_wdog_ports[] = {
 137   { "reset", WDEV_RESET, 0, output_port, },
 138   { "nmi",   WDEV_NMI,   0, output_port, },
 139   { "gpi",   WDEV_GPI,   0, output_port, },
 140   { NULL, 0, 0, 0, },
 141 };
 142
 143 static void
 144 bfin_wdog_port_event (struct hw *me, int my_port, struct hw *source,
 145                       int source_port, int level)
 146 {
 147   struct bfin_wdog *wdog = hw_data (me);
 148   bu16 wdev;
 149
 150   wdog->ctl |= WDRO;
 151   wdev = (wdog->ctl & WDEV);
 152   if (wdev != WDEV_NONE)
 153     hw_port_event (me, wdev, 1);
 154 }
 155
 156 static void
 157 attach_bfin_wdog_regs (struct hw *me, struct bfin_wdog *wdog)
 158 {
 159   address_word attach_address;
 160   int attach_space;
 161   unsigned attach_size;
 162   reg_property_spec reg;
 163
 164   if (hw_find_property (me, "reg") == NULL)
 165     hw_abort (me, "Missing \"reg\" property");
 166
 167   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 168     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 169
 170   hw_unit_address_to_attach_address (hw_parent (me),
 171                                      &reg.address,
 172                                      &attach_space, &attach_address, me);
 173   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 174
 175   if (attach_size != BFIN_MMR_WDOG_SIZE)
 176     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_WDOG_SIZE);
 177
 178   hw_attach_address (hw_parent (me),
 179                      0, attach_space, attach_address, attach_size, me);
 180
 181   wdog->base = attach_address;
 182 }
 183
 184 static void
 185 bfin_wdog_finish (struct hw *me)
 186 {
 187   struct bfin_wdog *wdog;
 188
 189   wdog = HW_ZALLOC (me, struct bfin_wdog);
 190
 191   set_hw_data (me, wdog);
 192   set_hw_io_read_buffer (me, bfin_wdog_io_read_buffer);
 193   set_hw_io_write_buffer (me, bfin_wdog_io_write_buffer);
 194   set_hw_ports (me, bfin_wdog_ports);
 195   set_hw_port_event (me, bfin_wdog_port_event);
 196
 197   attach_bfin_wdog_regs (me, wdog);
 198
 199   /* Initialize the Watchdog.  */
 200   wdog->ctl = WDDIS;
 201 }
 202
 203 const struct hw_descriptor dv_bfin_wdog_descriptor[] = {
 204   {"bfin_wdog", bfin_wdog_finish,},
 205   {NULL, NULL},
 206 };