sim/bfin/dv-bfin_wdog.c

   1 /* Blackfin Watchdog (WDOG) model.
   2
   3    Copyright (C) 2010-2019 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   /* Invalid access mode is higher priority than missing register.  */
  65   if (!dv_bfin_mmr_require_16_32 (me, addr, nr_bytes, true))
  66     return 0;
  67
  68   if (nr_bytes == 4)
  69     value = dv_load_4 (source);
  70   else
  71     value = dv_load_2 (source);
  72
  73   mmr_off = addr - wdog->base;
  74   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
  75   value16p = valuep;
  76   value32p = valuep;
  77
  78   HW_TRACE_WRITE ();
  79
  80   switch (mmr_off)
  81     {
  82     case mmr_offset(ctl):
  83       dv_w1c_2_partial (value16p, value, WDRO);
  84       /* XXX: Should enable an event here to handle timeouts.  */
  85       break;
  86
  87     case mmr_offset(cnt):
  88       /* Writes are discarded when enabeld.  */
  89       if (!bfin_wdog_enabled (wdog))
  90         {
  91           *value32p = value;
  92           /* Writes to CNT preloads the STAT.  */
  93           wdog->stat = wdog->cnt;
  94         }
  95       break;
  96
  97     case mmr_offset(stat):
  98       /* When enabled, writes to STAT reload the counter.  */
  99       if (bfin_wdog_enabled (wdog))
 100         wdog->stat = wdog->cnt;
 101       /* XXX: When disabled, are writes just ignored ?  */
 102       break;
 103     }
 104
 105   return nr_bytes;
 106 }
 107
 108 static unsigned
 109 bfin_wdog_io_read_buffer (struct hw *me, void *dest,
 110                           int space, address_word addr, unsigned nr_bytes)
 111 {
 112   struct bfin_wdog *wdog = hw_data (me);
 113   bu32 mmr_off;
 114   bu16 *value16p;
 115   bu32 *value32p;
 116   void *valuep;
 117
 118   /* Invalid access mode is higher priority than missing register.  */
 119   if (!dv_bfin_mmr_require_16_32 (me, addr, nr_bytes, false))
 120     return 0;
 121
 122   mmr_off = addr - wdog->base;
 123   valuep = (void *)((unsigned long)wdog + mmr_base() + mmr_off);
 124   value16p = valuep;
 125   value32p = valuep;
 126
 127   HW_TRACE_READ ();
 128
 129   switch (mmr_off)
 130     {
 131     case mmr_offset(ctl):
 132       if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, false))
 133         return 0;
 134       dv_store_2 (dest, *value16p);
 135       break;
 136
 137     case mmr_offset(cnt):
 138     case mmr_offset(stat):
 139       dv_store_4 (dest, *value32p);
 140       break;
 141     }
 142
 143   return nr_bytes;
 144 }
 145
 146 static const struct hw_port_descriptor bfin_wdog_ports[] =
 147 {
 148   { "reset", WDEV_RESET, 0, output_port, },
 149   { "nmi",   WDEV_NMI,   0, output_port, },
 150   { "gpi",   WDEV_GPI,   0, output_port, },
 151   { NULL, 0, 0, 0, },
 152 };
 153
 154 static void
 155 bfin_wdog_port_event (struct hw *me, int my_port, struct hw *source,
 156                       int source_port, int level)
 157 {
 158   struct bfin_wdog *wdog = hw_data (me);
 159   bu16 wdev;
 160
 161   wdog->ctl |= WDRO;
 162   wdev = (wdog->ctl & WDEV);
 163   if (wdev != WDEV_NONE)
 164     hw_port_event (me, wdev, 1);
 165 }
 166
 167 static void
 168 attach_bfin_wdog_regs (struct hw *me, struct bfin_wdog *wdog)
 169 {
 170   address_word attach_address;
 171   int attach_space;
 172   unsigned attach_size;
 173   reg_property_spec reg;
 174
 175   if (hw_find_property (me, "reg") == NULL)
 176     hw_abort (me, "Missing \"reg\" property");
 177
 178   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 179     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 180
 181   hw_unit_address_to_attach_address (hw_parent (me),
 182                                      &reg.address,
 183                                      &attach_space, &attach_address, me);
 184   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 185
 186   if (attach_size != BFIN_MMR_WDOG_SIZE)
 187     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_WDOG_SIZE);
 188
 189   hw_attach_address (hw_parent (me),
 190                      0, attach_space, attach_address, attach_size, me);
 191
 192   wdog->base = attach_address;
 193 }
 194
 195 static void
 196 bfin_wdog_finish (struct hw *me)
 197 {
 198   struct bfin_wdog *wdog;
 199
 200   wdog = HW_ZALLOC (me, struct bfin_wdog);
 201
 202   set_hw_data (me, wdog);
 203   set_hw_io_read_buffer (me, bfin_wdog_io_read_buffer);
 204   set_hw_io_write_buffer (me, bfin_wdog_io_write_buffer);
 205   set_hw_ports (me, bfin_wdog_ports);
 206   set_hw_port_event (me, bfin_wdog_port_event);
 207
 208   attach_bfin_wdog_regs (me, wdog);
 209
 210   /* Initialize the Watchdog.  */
 211   wdog->ctl = WDDIS;
 212 }
 213
 214 const struct hw_descriptor dv_bfin_wdog_descriptor[] =
 215 {
 216   {"bfin_wdog", bfin_wdog_finish,},
 217   {NULL, NULL},
 218 };