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/*  This file is part of the program psim.

    Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

    */

#ifndef _HW_GLUE_C_

#define _HW_GLUE_C_

#include "device_table.h"

/* DEVICE

   glue - glue to interconnect and test interrupts

   DESCRIPTION

   The glue device provides two functions.  Firstly, it provides a

   mechanism for inspecting and driving the interrupt net.  Secondly,

   it provides a set of boolean primitives that can be used add

   combinatorial operations to the interrupt network.

   Glue devices have a variable number of big endian <<output>>

   registers.  Each host-word size.  The registers can be both read

   and written.

   Writing a value to an output register causes an interrupt (of the

   specified level) to be driven on the devices corresponding output

   interrupt port.

   Reading an <<output>> register returns either the last value

   written or the most recently computed value (for that register) as

   a result of an interrupt ariving (which ever was computed last).

   At present the following sub device types are available:

   <<glue>>: In addition to driving its output interrupt port with any

   value written to an interrupt input port is stored in the

   corresponding <<output>> register.  Such input interrupts, however,

   are not propogated to an output interrupt port.

   <<glue-and>>: The bit-wise AND of the interrupt inputs is computed

   and then both stored in <<output>> register zero and propogated to

   output interrupt output port zero.

   PROPERTIES

   reg = <address> <size> (required)

   Specify the address (within the parent bus) that this device is to

   live.  The address must be 2048 * sizeof(word) (8k in a 32bit

   simulation) aligned.

   interrupt-ranges = <int-number> <range> (optional)

   If present, this specifies the number of valid interrupt inputs (up

   to the maximum of 2048).  By default, <<int-number>> is zero and

   range is determined by the <<reg>> size.

   EXAMPLES

   Enable tracing of the device:

   | -t glue-device \

   Create source, bitwize-and, and sink glue devices.  Since the

   device at address <<0x10000>> is of size <<8>> it will have two

   output interrupt ports.

   | -o '/iobus@0xf0000000/glue@0x10000/reg 0x10000 8' \

   | -o '/iobus@0xf0000000/glue-and@0x20000/reg 0x20000 4' \

   | -o '/iobus@0xf0000000/glue-and/interrupt-ranges 0 2' \

   | -o '/iobus@0xf0000000/glue@0x30000/reg 0x30000 4' \

   Wire the two source interrupts to the AND device:

   | -o '/iobus@0xf0000000/glue@0x10000 > 0 0 /iobus/glue-and' \

   | -o '/iobus@0xf0000000/glue@0x10000 > 1 1 /iobus/glue-and' \

   Wire the AND device up to the sink so that the and's output is not

   left open.

   | -o '/iobus@0xf0000000/glue-and > 0 0 /iobus/glue@0x30000' \

   With the above configuration.  The client program is able to

   compute a two bit AND.  For instance the <<C>> stub below prints 1

   AND 0.

   |  unsigned *input = (void*)0xf0010000;

   |  unsigned *output = (void*)0xf0030000;

   |  unsigned ans;

   |  input[0] = htonl(1);

   |  input[1] = htonl(0);

   |  ans = ntohl(*output);

   |  write_string("AND is ");

   |  write_int(ans);

   |  write_line();

   BUGS

   A future implementation of this device may support multiple

   interrupt ranges.

   Some of the devices listed may not yet be fully implemented.

   Additional devices such as a dff, an inverter or a latch may be

   useful.

   */

enum {

  max_nr_interrupts = 2048,

};

typedef enum _hw_glue_type {

  glue_undefined = 0,

  glue_io,

  glue_and,

  glue_nand,

  glue_or,

  glue_xor,

  glue_nor,

  glue_not,

} hw_glue_type;

typedef struct _hw_glue_device {

  hw_glue_type type;

  int int_number;

  int *input;

  int nr_inputs;

  unsigned sizeof_input;

  /* our output registers */

  int space;

  unsigned_word address;

  unsigned sizeof_output;

  int *output;

  int nr_outputs;

} hw_glue_device;

static void

hw_glue_init_address(device *me)

{

  hw_glue_device *glue = (hw_glue_device*)device_data(me);

  /* attach to my parent */

  generic_device_init_address(me);

  /* establish the output registers */

  if (glue->output != NULL) {

    memset(glue->output, 0, glue->sizeof_output);

  }

  else {

    reg_property_spec unit;

    int reg_nr;

    /* find a relevant reg entry */

    reg_nr = 0;

    while (device_find_reg_array_property(me, "reg", reg_nr, &unit)

           && !device_size_to_attach_size(device_parent(me), &unit.size,

                                          &glue->sizeof_output, me))

      reg_nr++;

    /* check out the size */

    if (glue->sizeof_output == 0)

      device_error(me, "at least one reg property size must be nonzero");

    if (glue->sizeof_output % sizeof(unsigned_word) != 0)

      device_error(me, "reg property size must be %d aligned", sizeof(unsigned_word));

    /* and the address */

    device_address_to_attach_address(device_parent(me),

                                     &unit.address, &glue->space, &glue->address,

                                     me);

    if (glue->address % (sizeof(unsigned_word) * max_nr_interrupts) != 0)

      device_error(me, "reg property address must be %d aligned",

                   sizeof(unsigned_word) * max_nr_interrupts);

    glue->nr_outputs = glue->sizeof_output / sizeof(unsigned_word);

    glue->output = zalloc(glue->sizeof_output);

  }

  /* establish the input interrupt ports */

  if (glue->input != NULL) {

    memset(glue->input, 0, glue->sizeof_input);

  }

  else {

    const device_property *ranges = device_find_property(me, "interrupt-ranges");

    if (ranges == NULL) {

      glue->int_number = 0;

      glue->nr_inputs = glue->nr_outputs;

    }

    else if (ranges->sizeof_array != sizeof(unsigned_cell) * 2) {

      device_error(me, "invalid interrupt-ranges property (incorrect size)");

    }

    else {

      const unsigned_cell *int_range = ranges->array;

      glue->int_number = BE2H_cell(int_range[0]);

      glue->nr_inputs = BE2H_cell(int_range[1]);

    }

    glue->sizeof_input = glue->nr_inputs * sizeof(unsigned);

    glue->input = zalloc(glue->sizeof_input);

  }

  /* determine our type */

  if (glue->type == glue_undefined) {

    const char *name = device_name(me);

    if (strcmp(name, "glue") == 0)

      glue->type = glue_io;

    else if (strcmp(name, "glue-and") == 0)

      glue->type = glue_and;

    else

      device_error(me, "unimplemented glue type");

  }

  DTRACE(glue, ("int-number %d, nr_inputs %d, nr_outputs %d\n",

                glue->int_number, glue->nr_inputs, glue->nr_outputs));

}

static unsigned

hw_glue_io_read_buffer_callback(device *me,

                                void *dest,

                                int space,

                                unsigned_word addr,

                                unsigned nr_bytes,

                                cpu *processor,

                                unsigned_word cia)

{

  hw_glue_device *glue = (hw_glue_device*)device_data(me);

  int reg = ((addr - glue->address) / sizeof(unsigned_word)) % glue->nr_outputs;

  if (nr_bytes != sizeof(unsigned_word)

      || (addr % sizeof(unsigned_word)) != 0)

     device_error(me, "missaligned read access (%d:0x%lx:%d) not supported",

                  space, (unsigned long)addr, nr_bytes);

  *(unsigned_word*)dest = H2BE_4(glue->output[reg]);

  DTRACE(glue, ("read - interrupt %d (0x%lx), level %d\n",

                reg, (unsigned long) addr, glue->output[reg]));

  return nr_bytes;

}

static unsigned

hw_glue_io_write_buffer_callback(device *me,

                                 const void *source,

                                 int space,

                                 unsigned_word addr,

                                 unsigned nr_bytes,

                                 cpu *processor,

                                 unsigned_word cia)

{

  hw_glue_device *glue = (hw_glue_device*)device_data(me);

  int reg = ((addr - glue->address) / sizeof(unsigned_word)) % max_nr_interrupts;

  if (nr_bytes != sizeof(unsigned_word)

      || (addr % sizeof(unsigned_word)) != 0)

    device_error(me, "missaligned write access (%d:0x%lx:%d) not supported",

                 space, (unsigned long)addr, nr_bytes);

  glue->output[reg] = H2BE_4(*(unsigned_word*)source);

  DTRACE(glue, ("write - interrupt %d (0x%lx), level %d\n",

                reg, (unsigned long) addr, glue->output[reg]));

  device_interrupt_event(me, reg, glue->output[reg], processor, cia);

  return nr_bytes;

}

static void

hw_glue_interrupt_event(device *me,

                        int my_port,

                        device *source,

                        int source_port,

                        int level,

                        cpu *processor,

                        unsigned_word cia)

{

  hw_glue_device *glue = (hw_glue_device*)device_data(me);

  int i;

  if (my_port < glue->int_number

      || my_port >= glue->int_number + glue->nr_inputs)

    device_error(me, "interrupt %d outside of valid range", my_port);

  glue->input[my_port - glue->int_number] = level;

  switch (glue->type) {

  case glue_io:

    {

      int port = my_port % glue->nr_outputs;

      glue->output[port] = level;

      DTRACE(glue, ("input - interrupt %d (0x%lx), level %d\n",

                    my_port,

                    (unsigned long)glue->address + port * sizeof(unsigned_word),

                    level));

      break;

    }

  case glue_and:

    glue->output[0] = glue->input[0];

    for (i = 1; i < glue->nr_inputs; i++)

      glue->output[0] &= glue->input[i];

    DTRACE(glue, ("and - interrupt %d, level %d arrived - output %d\n",

                  my_port, level, glue->output[0]));

    device_interrupt_event(me, 0, glue->output[0], processor, cia);

    break;

  default:

    device_error(me, "operator not implemented");

    break;

  }

}

static const device_interrupt_port_descriptor hw_glue_interrupt_ports[] = {

  { "int", 0, max_nr_interrupts },

  { NULL }

};

static device_callbacks const hw_glue_callbacks = {

  { hw_glue_init_address, NULL },

  { NULL, }, /* address */

  { hw_glue_io_read_buffer_callback,

      hw_glue_io_write_buffer_callback, },

  { NULL, }, /* DMA */

  { hw_glue_interrupt_event, NULL, hw_glue_interrupt_ports }, /* interrupt */

  { NULL, }, /* unit */

  NULL, /* instance */

};

static void *

hw_glue_create(const char *name,

              const device_unit *unit_address,

              const char *args)

{

  /* create the descriptor */

  hw_glue_device *glue = ZALLOC(hw_glue_device);

  return glue;

}

const device_descriptor hw_glue_device_descriptor[] = {

  { "glue", hw_glue_create, &hw_glue_callbacks },

  { "glue-and", hw_glue_create, &hw_glue_callbacks },

  { "glue-nand", hw_glue_create, &hw_glue_callbacks },

  { "glue-or", hw_glue_create, &hw_glue_callbacks },

  { "glue-xor", hw_glue_create, &hw_glue_callbacks },

  { "glue-nor", hw_glue_create, &hw_glue_callbacks },

  { "glue-not", hw_glue_create, &hw_glue_callbacks },

  { NULL },

};

#endif /* _HW_GLUE_C_ */