sim/bfin/dv-bfin_uart2.c

   1 /* Blackfin Universal Asynchronous Receiver/Transmitter (UART) model.
   2    For "new style" UARTs on BF50x/BF54x parts.
   3
   4    Copyright (C) 2010-2023 Free Software Foundation, Inc.
   5    Contributed by Analog Devices, Inc.
   6
   7    This file is part of simulators.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 /* This must come before any other includes.  */
  23 #include "defs.h"
  24
  25 #include "sim-main.h"
  26 #include "devices.h"
  27 #include "dv-bfin_uart2.h"
  28
  29 /* XXX: Should we bother emulating the TX/RX FIFOs ?  */
  30
  31 /* Internal state needs to be the same as bfin_uart.  */
  32 struct bfin_uart
  33 {
  34   /* This top portion matches common dv_bfin struct.  */
  35   bu32 base;
  36   struct hw *dma_master;
  37   bool acked;
  38
  39   struct hw_event *handler;
  40   char saved_byte;
  41   int saved_count;
  42
  43   /* Accessed indirectly by ier_{set,clear}.  */
  44   bu16 ier;
  45
  46   /* Order after here is important -- matches hardware MMR layout.  */
  47   bu16 BFIN_MMR_16(dll);
  48   bu16 BFIN_MMR_16(dlh);
  49   bu16 BFIN_MMR_16(gctl);
  50   bu16 BFIN_MMR_16(lcr);
  51   bu16 BFIN_MMR_16(mcr);
  52   bu16 BFIN_MMR_16(lsr);
  53   bu16 BFIN_MMR_16(msr);
  54   bu16 BFIN_MMR_16(scr);
  55   bu16 BFIN_MMR_16(ier_set);
  56   bu16 BFIN_MMR_16(ier_clear);
  57   bu16 BFIN_MMR_16(thr);
  58   bu16 BFIN_MMR_16(rbr);
  59 };
  60 #define mmr_base()      offsetof(struct bfin_uart, dll)
  61 #define mmr_offset(mmr) (offsetof(struct bfin_uart, mmr) - mmr_base())
  62
  63 static const char * const mmr_names[] =
  64 {
  65   "UART_DLL", "UART_DLH", "UART_GCTL", "UART_LCR", "UART_MCR", "UART_LSR",
  66   "UART_MSR", "UART_SCR", "UART_IER_SET", "UART_IER_CLEAR", "UART_THR",
  67   "UART_RBR",
  68 };
  69 #define mmr_name(off) mmr_names[(off) / 4]
  70
  71 static unsigned
  72 bfin_uart_io_write_buffer (struct hw *me, const void *source,
  73                            int space, address_word addr, unsigned nr_bytes)
  74 {
  75   struct bfin_uart *uart = hw_data (me);
  76   bu32 mmr_off;
  77   bu32 value;
  78   bu16 *valuep;
  79
  80   /* Invalid access mode is higher priority than missing register.  */
  81   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, true))
  82     return 0;
  83
  84   value = dv_load_2 (source);
  85   mmr_off = addr - uart->base;
  86   valuep = (void *)((uintptr_t)uart + mmr_base() + mmr_off);
  87
  88   HW_TRACE_WRITE ();
  89
  90   /* XXX: All MMRs are "8bit" ... what happens to high 8bits ?  */
  91
  92   switch (mmr_off)
  93     {
  94     case mmr_offset(thr):
  95       uart->thr = bfin_uart_write_byte (me, value, uart->mcr);
  96       if (uart->ier & ETBEI)
  97         hw_port_event (me, DV_PORT_TX, 1);
  98       break;
  99     case mmr_offset(ier_set):
 100       uart->ier |= value;
 101       break;
 102     case mmr_offset(ier_clear):
 103       dv_w1c_2 (&uart->ier, value, -1);
 104       break;
 105     case mmr_offset(lsr):
 106       dv_w1c_2 (valuep, value, TFI | BI | FE | PE | OE);
 107       break;
 108     case mmr_offset(rbr):
 109       /* XXX: Writes are ignored ?  */
 110       break;
 111     case mmr_offset(msr):
 112       dv_w1c_2 (valuep, value, SCTS);
 113       break;
 114     case mmr_offset(dll):
 115     case mmr_offset(dlh):
 116     case mmr_offset(gctl):
 117     case mmr_offset(lcr):
 118     case mmr_offset(mcr):
 119     case mmr_offset(scr):
 120       *valuep = value;
 121       break;
 122     default:
 123       dv_bfin_mmr_invalid (me, addr, nr_bytes, true);
 124       return 0;
 125     }
 126
 127   return nr_bytes;
 128 }
 129
 130 static unsigned
 131 bfin_uart_io_read_buffer (struct hw *me, void *dest,
 132                           int space, address_word addr, unsigned nr_bytes)
 133 {
 134   struct bfin_uart *uart = hw_data (me);
 135   bu32 mmr_off;
 136   bu16 *valuep;
 137
 138   /* Invalid access mode is higher priority than missing register.  */
 139   if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, false))
 140     return 0;
 141
 142   mmr_off = addr - uart->base;
 143   valuep = (void *)((uintptr_t)uart + mmr_base() + mmr_off);
 144
 145   HW_TRACE_READ ();
 146
 147   switch (mmr_off)
 148     {
 149     case mmr_offset(rbr):
 150       uart->rbr = bfin_uart_get_next_byte (me, uart->rbr, uart->mcr, NULL);
 151       dv_store_2 (dest, uart->rbr);
 152       break;
 153     case mmr_offset(ier_set):
 154     case mmr_offset(ier_clear):
 155       dv_store_2 (dest, uart->ier);
 156       bfin_uart_reschedule (me);
 157       break;
 158     case mmr_offset(lsr):
 159       uart->lsr &= ~(DR | THRE | TEMT);
 160       uart->lsr |= bfin_uart_get_status (me);
 161     case mmr_offset(thr):
 162     case mmr_offset(msr):
 163     case mmr_offset(dll):
 164     case mmr_offset(dlh):
 165     case mmr_offset(gctl):
 166     case mmr_offset(lcr):
 167     case mmr_offset(mcr):
 168     case mmr_offset(scr):
 169       dv_store_2 (dest, *valuep);
 170       break;
 171     default:
 172       dv_bfin_mmr_invalid (me, addr, nr_bytes, false);
 173       return 0;
 174     }
 175
 176   return nr_bytes;
 177 }
 178
 179 static unsigned
 180 bfin_uart_dma_read_buffer (struct hw *me, void *dest, int space,
 181                            unsigned_word addr, unsigned nr_bytes)
 182 {
 183   HW_TRACE_DMA_READ ();
 184   return bfin_uart_read_buffer (me, dest, nr_bytes);
 185 }
 186
 187 static unsigned
 188 bfin_uart_dma_write_buffer (struct hw *me, const void *source,
 189                             int space, unsigned_word addr,
 190                             unsigned nr_bytes,
 191                             int violate_read_only_section)
 192 {
 193   struct bfin_uart *uart = hw_data (me);
 194   unsigned ret;
 195
 196   HW_TRACE_DMA_WRITE ();
 197
 198   ret = bfin_uart_write_buffer (me, source, nr_bytes);
 199
 200   if (ret == nr_bytes && (uart->ier & ETBEI))
 201     hw_port_event (me, DV_PORT_TX, 1);
 202
 203   return ret;
 204 }
 205
 206 static const struct hw_port_descriptor bfin_uart_ports[] =
 207 {
 208   { "tx",   DV_PORT_TX,   0, output_port, },
 209   { "rx",   DV_PORT_RX,   0, output_port, },
 210   { "stat", DV_PORT_STAT, 0, output_port, },
 211   { NULL, 0, 0, 0, },
 212 };
 213
 214 static void
 215 attach_bfin_uart_regs (struct hw *me, struct bfin_uart *uart)
 216 {
 217   address_word attach_address;
 218   int attach_space;
 219   unsigned attach_size;
 220   reg_property_spec reg;
 221
 222   if (hw_find_property (me, "reg") == NULL)
 223     hw_abort (me, "Missing \"reg\" property");
 224
 225   if (!hw_find_reg_array_property (me, "reg", 0, &reg))
 226     hw_abort (me, "\"reg\" property must contain three addr/size entries");
 227
 228   hw_unit_address_to_attach_address (hw_parent (me),
 229                                      &reg.address,
 230                                      &attach_space, &attach_address, me);
 231   hw_unit_size_to_attach_size (hw_parent (me), &reg.size, &attach_size, me);
 232
 233   if (attach_size != BFIN_MMR_UART2_SIZE)
 234     hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_UART2_SIZE);
 235
 236   hw_attach_address (hw_parent (me),
 237                      0, attach_space, attach_address, attach_size, me);
 238
 239   uart->base = attach_address;
 240 }
 241
 242 static void
 243 bfin_uart_finish (struct hw *me)
 244 {
 245   struct bfin_uart *uart;
 246
 247   uart = HW_ZALLOC (me, struct bfin_uart);
 248
 249   set_hw_data (me, uart);
 250   set_hw_io_read_buffer (me, bfin_uart_io_read_buffer);
 251   set_hw_io_write_buffer (me, bfin_uart_io_write_buffer);
 252   set_hw_dma_read_buffer (me, bfin_uart_dma_read_buffer);
 253   set_hw_dma_write_buffer (me, bfin_uart_dma_write_buffer);
 254   set_hw_ports (me, bfin_uart_ports);
 255
 256   attach_bfin_uart_regs (me, uart);
 257
 258   /* Initialize the UART.  */
 259   uart->dll = 0x0001;
 260   uart->lsr = 0x0060;
 261 }
 262
 263 const struct hw_descriptor dv_bfin_uart2_descriptor[] =
 264 {
 265   {"bfin_uart2", bfin_uart_finish,},
 266   {NULL, NULL},
 267 };