sim/bfin/dv-bfin_twi.c

   1 /* Blackfin Two Wire Interface (TWI) model
   2
   3    Copyright (C) 2010-2024 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 /* This must come before any other includes.  */
  22 #include "defs.h"
  23
  24 #include "sim-main.h"
  25 #include "devices.h"
  26 #include "dv-bfin_twi.h"
  27
  28 /* XXX: This is merely a stub.  */
  29
  30 struct bfin_twi
  31 {
  32   /* This top portion matches common dv_bfin struct.  */
  33   bu32 base;
  34   struct hw *dma_master;
  35   bool acked;
  36
  37   struct hw_event *handler;
  38   char saved_byte;
  39   int saved_count;
  40
  41   bu16 xmt_fifo, rcv_fifo;
  42
  43   /* Order after here is important -- matches hardware MMR layout.  */
  44   bu16 BFIN_MMR_16(clkdiv);
  45   bu16 BFIN_MMR_16(control);
  46   bu16 BFIN_MMR_16(slave_ctl);
  47   bu16 BFIN_MMR_16(slave_stat);
  48   bu16 BFIN_MMR_16(slave_addr);
  49   bu16 BFIN_MMR_16(master_ctl);
  50   bu16 BFIN_MMR_16(master_stat);
  51   bu16 BFIN_MMR_16(master_addr);
  52   bu16 BFIN_MMR_16(int_stat);
  53   bu16 BFIN_MMR_16(int_mask);
  54   bu16 BFIN_MMR_16(fifo_ctl);
  55   bu16 BFIN_MMR_16(fifo_stat);
  56   bu32 _pad0[20];
  57   bu16 BFIN_MMR_16(xmt_data8);
  58   bu16 BFIN_MMR_16(xmt_data16);
  59   bu16 BFIN_MMR_16(rcv_data8);
  60   bu16 BFIN_MMR_16(rcv_data16);
  61 };
  62 #define mmr_base()      offsetof(struct bfin_twi, clkdiv)
  63 #define mmr_offset(mmr) (offsetof(struct bfin_twi, mmr) - mmr_base())
  64 #define mmr_idx(mmr)    (mmr_offset (mmr) / 4)
  65
  66 static const char * const mmr_names[] =
  67 {
  68   "TWI_CLKDIV", "TWI_CONTROL", "TWI_SLAVE_CTL", "TWI_SLAVE_STAT",
  69   "TWI_SLAVE_ADDR", "TWI_MASTER_CTL", "TWI_MASTER_STAT", "TWI_MASTER_ADDR",
  70   "TWI_INT_STAT", "TWI_INT_MASK", "TWI_FIFO_CTL", "TWI_FIFO_STAT",
  71   [mmr_idx (xmt_data8)] = "TWI_XMT_DATA8", "TWI_XMT_DATA16", "TWI_RCV_DATA8",
  72   "TWI_RCV_DATA16",
  73 };
  74 #define mmr_name(off) (mmr_names[(off) / 4] ? : "<INV>")
  75
  76 static unsigned
  77 bfin_twi_io_write_buffer (struct hw *me, const void *source, int space,
  78                           address_word addr, unsigned nr_bytes)
  79 {
  80   struct bfin_twi *twi = hw_data (me);
  81   bu32 mmr_off;
  82   bu32 value;
  83   bu16 *valuep;
  84
  85   /* Invalid access mode is higher priority than missing register.  */
  86   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, true))
  87     return 0;
  88
  89   value = dv_load_2 (source);
  90   mmr_off = addr - twi->base;
  91   valuep = (void *)((uintptr_t)twi + mmr_base() + mmr_off);
  92
  93   HW_TRACE_WRITE ();
  94
  95   switch (mmr_off)
  96     {
  97     case mmr_offset(clkdiv):
  98     case mmr_offset(control):
  99     case mmr_offset(slave_ctl):
 100     case mmr_offset(slave_addr):
 101     case mmr_offset(master_ctl):
 102     case mmr_offset(master_addr):
 103     case mmr_offset(int_mask):
 104     case mmr_offset(fifo_ctl):
 105       *valuep = value;
 106       break;
 107     case mmr_offset(int_stat):
 108       dv_w1c_2 (valuep, value, -1);
 109       break;
 110     case mmr_offset(master_stat):
 111       dv_w1c_2 (valuep, value, BUFWRERR | BUFRDERR | DNAK | ANAK | LOSTARB);
 112       break;
 113     case mmr_offset(slave_stat):
 114     case mmr_offset(fifo_stat):
 115     case mmr_offset(rcv_data8):
 116     case mmr_offset(rcv_data16):
 117       /* These are all RO.  XXX: Does these throw error ?  */
 118       break;
 119     case mmr_offset(xmt_data8):
 120       value &= 0xff;
 121       ATTRIBUTE_FALLTHROUGH;
 122     case mmr_offset(xmt_data16):
 123       twi->xmt_fifo = value;
 124       break;
 125     default:
 126       dv_bfin_mmr_invalid (me, addr, nr_bytes, true);
 127       return 0;
 128     }
 129
 130   return nr_bytes;
 131 }
 132
 133 static unsigned
 134 bfin_twi_io_read_buffer (struct hw *me, void *dest, int space,
 135                          address_word addr, unsigned nr_bytes)
 136 {
 137   struct bfin_twi *twi = hw_data (me);
 138   bu32 mmr_off;
 139   bu16 *valuep;
 140
 141   /* Invalid access mode is higher priority than missing register.  */
 142   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, false))
 143     return 0;
 144
 145   mmr_off = addr - twi->base;
 146   valuep = (void *)((uintptr_t)twi + mmr_base() + mmr_off);
 147
 148   HW_TRACE_READ ();
 149
 150   switch (mmr_off)
 151     {
 152     case mmr_offset(clkdiv):
 153     case mmr_offset(control):
 154     case mmr_offset(slave_ctl):
 155     case mmr_offset(slave_stat):
 156     case mmr_offset(slave_addr):
 157     case mmr_offset(master_ctl):
 158     case mmr_offset(master_stat):
 159     case mmr_offset(master_addr):
 160     case mmr_offset(int_stat):
 161     case mmr_offset(int_mask):
 162     case mmr_offset(fifo_ctl):
 163     case mmr_offset(fifo_stat):
 164       dv_store_2 (dest, *valuep);
 165       break;
 166     case mmr_offset(rcv_data8):
 167     case mmr_offset(rcv_data16):
 168       dv_store_2 (dest, twi->rcv_fifo);
 169       break;
 170     case mmr_offset(xmt_data8):
 171     case mmr_offset(xmt_data16):
 172       /* These always read as 0.  */
 173       dv_store_2 (dest, 0);
 174       break;
 175     default:
 176       dv_bfin_mmr_invalid (me, addr, nr_bytes, false);
 177       return 0;
 178     }
 179
 180   return nr_bytes;
 181 }
 182
 183 static const struct hw_port_descriptor bfin_twi_ports[] =
 184 {
 185   { "stat", 0, 0, output_port, },
 186   { NULL, 0, 0, 0, },
 187 };
 188
 189 static void
 190 attach_bfin_twi_regs (struct hw *me, struct bfin_twi *twi)
 191 {
 192   address_word attach_address;
 193   int attach_space;
 194   unsigned attach_size;
 195   reg_property_spec reg;
 196
 197   if (hw_find_property (me, "reg") == NULL)
 198     hw_abort (me, "Missing \"reg\" property");
 199
 200   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 201     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 202
 203   hw_unit_address_to_attach_address (hw_parent (me),
 204                                      &reg.address,
 205                                      &attach_space, &attach_address, me);
 206   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 207
 208   if (attach_size != BFIN_MMR_TWI_SIZE)
 209     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_TWI_SIZE);
 210
 211   hw_attach_address (hw_parent (me),
 212                      0, attach_space, attach_address, attach_size, me);
 213
 214   twi->base = attach_address;
 215 }
 216
 217 static void
 218 bfin_twi_finish (struct hw *me)
 219 {
 220   struct bfin_twi *twi;
 221
 222   twi = HW_ZALLOC (me, struct bfin_twi);
 223
 224   set_hw_data (me, twi);
 225   set_hw_io_read_buffer (me, bfin_twi_io_read_buffer);
 226   set_hw_io_write_buffer (me, bfin_twi_io_write_buffer);
 227   set_hw_ports (me, bfin_twi_ports);
 228
 229   attach_bfin_twi_regs (me, twi);
 230 }
 231
 232 const struct hw_descriptor dv_bfin_twi_descriptor[] =
 233 {
 234   {"bfin_twi", bfin_twi_finish,},
 235   {NULL, NULL},
 236 };