sim/bfin/dv-bfin_twi.c

   1 /* Blackfin Two Wire Interface (TWI) model
   2
   3    Copyright (C) 2010-2020 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 "devices.h"
  25 #include "dv-bfin_twi.h"
  26
  27 /* XXX: This is merely a stub.  */
  28
  29 struct bfin_twi
  30 {
  31   /* This top portion matches common dv_bfin struct.  */
  32   bu32 base;
  33   struct hw *dma_master;
  34   bool acked;
  35
  36   struct hw_event *handler;
  37   char saved_byte;
  38   int saved_count;
  39
  40   bu16 xmt_fifo, rcv_fifo;
  41
  42   /* Order after here is important -- matches hardware MMR layout.  */
  43   bu16 BFIN_MMR_16(clkdiv);
  44   bu16 BFIN_MMR_16(control);
  45   bu16 BFIN_MMR_16(slave_ctl);
  46   bu16 BFIN_MMR_16(slave_stat);
  47   bu16 BFIN_MMR_16(slave_addr);
  48   bu16 BFIN_MMR_16(master_ctl);
  49   bu16 BFIN_MMR_16(master_stat);
  50   bu16 BFIN_MMR_16(master_addr);
  51   bu16 BFIN_MMR_16(int_stat);
  52   bu16 BFIN_MMR_16(int_mask);
  53   bu16 BFIN_MMR_16(fifo_ctl);
  54   bu16 BFIN_MMR_16(fifo_stat);
  55   bu32 _pad0[20];
  56   bu16 BFIN_MMR_16(xmt_data8);
  57   bu16 BFIN_MMR_16(xmt_data16);
  58   bu16 BFIN_MMR_16(rcv_data8);
  59   bu16 BFIN_MMR_16(rcv_data16);
  60 };
  61 #define mmr_base()      offsetof(struct bfin_twi, clkdiv)
  62 #define mmr_offset(mmr) (offsetof(struct bfin_twi, mmr) - mmr_base())
  63 #define mmr_idx(mmr)    (mmr_offset (mmr) / 4)
  64
  65 static const char * const mmr_names[] =
  66 {
  67   "TWI_CLKDIV", "TWI_CONTROL", "TWI_SLAVE_CTL", "TWI_SLAVE_STAT",
  68   "TWI_SLAVE_ADDR", "TWI_MASTER_CTL", "TWI_MASTER_STAT", "TWI_MASTER_ADDR",
  69   "TWI_INT_STAT", "TWI_INT_MASK", "TWI_FIFO_CTL", "TWI_FIFO_STAT",
  70   [mmr_idx (xmt_data8)] = "TWI_XMT_DATA8", "TWI_XMT_DATA16", "TWI_RCV_DATA8",
  71   "TWI_RCV_DATA16",
  72 };
  73 #define mmr_name(off) (mmr_names[(off) / 4] ? : "<INV>")
  74
  75 static unsigned
  76 bfin_twi_io_write_buffer (struct hw *me, const void *source, int space,
  77                           address_word addr, unsigned nr_bytes)
  78 {
  79   struct bfin_twi *twi = hw_data (me);
  80   bu32 mmr_off;
  81   bu32 value;
  82   bu16 *valuep;
  83
  84   /* Invalid access mode is higher priority than missing register.  */
  85   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, true))
  86     return 0;
  87
  88   value = dv_load_2 (source);
  89   mmr_off = addr - twi->base;
  90   valuep = (void *)((unsigned long)twi + mmr_base() + mmr_off);
  91
  92   HW_TRACE_WRITE ();
  93
  94   switch (mmr_off)
  95     {
  96     case mmr_offset(clkdiv):
  97     case mmr_offset(control):
  98     case mmr_offset(slave_ctl):
  99     case mmr_offset(slave_addr):
 100     case mmr_offset(master_ctl):
 101     case mmr_offset(master_addr):
 102     case mmr_offset(int_mask):
 103     case mmr_offset(fifo_ctl):
 104       *valuep = value;
 105       break;
 106     case mmr_offset(int_stat):
 107       dv_w1c_2 (valuep, value, -1);
 108       break;
 109     case mmr_offset(master_stat):
 110       dv_w1c_2 (valuep, value, BUFWRERR | BUFRDERR | DNAK | ANAK | LOSTARB);
 111       break;
 112     case mmr_offset(slave_stat):
 113     case mmr_offset(fifo_stat):
 114     case mmr_offset(rcv_data8):
 115     case mmr_offset(rcv_data16):
 116       /* These are all RO.  XXX: Does these throw error ?  */
 117       break;
 118     case mmr_offset(xmt_data8):
 119       value &= 0xff;
 120     case mmr_offset(xmt_data16):
 121       twi->xmt_fifo = value;
 122       break;
 123     default:
 124       dv_bfin_mmr_invalid (me, addr, nr_bytes, true);
 125       return 0;
 126     }
 127
 128   return nr_bytes;
 129 }
 130
 131 static unsigned
 132 bfin_twi_io_read_buffer (struct hw *me, void *dest, int space,
 133                          address_word addr, unsigned nr_bytes)
 134 {
 135   struct bfin_twi *twi = hw_data (me);
 136   bu32 mmr_off;
 137   bu16 *valuep;
 138
 139   /* Invalid access mode is higher priority than missing register.  */
 140   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, false))
 141     return 0;
 142
 143   mmr_off = addr - twi->base;
 144   valuep = (void *)((unsigned long)twi + mmr_base() + mmr_off);
 145
 146   HW_TRACE_READ ();
 147
 148   switch (mmr_off)
 149     {
 150     case mmr_offset(clkdiv):
 151     case mmr_offset(control):
 152     case mmr_offset(slave_ctl):
 153     case mmr_offset(slave_stat):
 154     case mmr_offset(slave_addr):
 155     case mmr_offset(master_ctl):
 156     case mmr_offset(master_stat):
 157     case mmr_offset(master_addr):
 158     case mmr_offset(int_stat):
 159     case mmr_offset(int_mask):
 160     case mmr_offset(fifo_ctl):
 161     case mmr_offset(fifo_stat):
 162       dv_store_2 (dest, *valuep);
 163       break;
 164     case mmr_offset(rcv_data8):
 165     case mmr_offset(rcv_data16):
 166       dv_store_2 (dest, twi->rcv_fifo);
 167       break;
 168     case mmr_offset(xmt_data8):
 169     case mmr_offset(xmt_data16):
 170       /* These always read as 0.  */
 171       dv_store_2 (dest, 0);
 172       break;
 173     default:
 174       dv_bfin_mmr_invalid (me, addr, nr_bytes, false);
 175       return 0;
 176     }
 177
 178   return nr_bytes;
 179 }
 180
 181 static const struct hw_port_descriptor bfin_twi_ports[] =
 182 {
 183   { "stat", 0, 0, output_port, },
 184   { NULL, 0, 0, 0, },
 185 };
 186
 187 static void
 188 attach_bfin_twi_regs (struct hw *me, struct bfin_twi *twi)
 189 {
 190   address_word attach_address;
 191   int attach_space;
 192   unsigned attach_size;
 193   reg_property_spec reg;
 194
 195   if (hw_find_property (me, "reg") == NULL)
 196     hw_abort (me, "Missing \"reg\" property");
 197
 198   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 199     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 200
 201   hw_unit_address_to_attach_address (hw_parent (me),
 202                                      &reg.address,
 203                                      &attach_space, &attach_address, me);
 204   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 205
 206   if (attach_size != BFIN_MMR_TWI_SIZE)
 207     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_TWI_SIZE);
 208
 209   hw_attach_address (hw_parent (me),
 210                      0, attach_space, attach_address, attach_size, me);
 211
 212   twi->base = attach_address;
 213 }
 214
 215 static void
 216 bfin_twi_finish (struct hw *me)
 217 {
 218   struct bfin_twi *twi;
 219
 220   twi = HW_ZALLOC (me, struct bfin_twi);
 221
 222   set_hw_data (me, twi);
 223   set_hw_io_read_buffer (me, bfin_twi_io_read_buffer);
 224   set_hw_io_write_buffer (me, bfin_twi_io_write_buffer);
 225   set_hw_ports (me, bfin_twi_ports);
 226
 227   attach_bfin_twi_regs (me, twi);
 228 }
 229
 230 const struct hw_descriptor dv_bfin_twi_descriptor[] =
 231 {
 232   {"bfin_twi", bfin_twi_finish,},
 233   {NULL, NULL},
 234 };