binutils-gdb/sim/m68hc11/dv-m68hc11spi.c
Mike Frysinger 6df01ab8ab sim: switch config.h usage to defs.h
The defs.h header will take care of including the various config.h
headers.  For now, it's just config.h, but we'll add more when we
integrate gnulib in.

This header should be used instead of config.h, and should be the
first include in every .c file.  We won't rely on the old behavior
where we expected files to include the port's sim-main.h which then
includes the common sim-basics.h which then includes config.h.  We
have a ton of code that includes things before sim-main.h, and it
sometimes needs to be that way.  Creating a dedicated header avoids
the ordering mess and implicit inclusion that shows up otherwise.
2021-05-16 22:38:41 -04:00

538 lines
13 KiB
C

/* dv-m68hc11spi.c -- Simulation of the 68HC11 SPI
Copyright (C) 2000-2021 Free Software Foundation, Inc.
Written by Stephane Carrez (stcarrez@nerim.fr)
(From a driver model Contributed by Cygnus Solutions.)
This file is part of the program GDB, the GNU debugger.
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 3 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, see <http://www.gnu.org/licenses/>.
*/
/* This must come before any other includes. */
#include "defs.h"
#include "sim-main.h"
#include "hw-main.h"
#include "dv-sockser.h"
#include "sim-assert.h"
/* DEVICE
m68hc11spi - m68hc11 SPI interface
DESCRIPTION
Implements the m68hc11 Synchronous Serial Peripheral Interface
described in the m68hc11 user guide (Chapter 8 in pink book).
The SPI I/O controller is directly connected to the CPU
interrupt. The simulator implements:
- SPI clock emulation
- Data transfer
- Write collision detection
PROPERTIES
None
PORTS
reset (input)
Reset port. This port is only used to simulate a reset of the SPI
I/O controller. It should be connected to the RESET output of the cpu.
*/
/* port ID's */
enum
{
RESET_PORT
};
static const struct hw_port_descriptor m68hc11spi_ports[] =
{
{ "reset", RESET_PORT, 0, input_port, },
{ NULL, },
};
/* SPI */
struct m68hc11spi
{
/* Information about next character to be transmited. */
unsigned char tx_char;
int tx_bit;
unsigned char mode;
unsigned char rx_char;
unsigned char rx_clear_scsr;
unsigned char clk_pin;
/* SPI clock rate (twice the real clock). */
unsigned int clock;
/* Periodic SPI event. */
struct hw_event* spi_event;
};
/* Finish off the partially created hw device. Attach our local
callbacks. Wire up our port names etc */
static hw_io_read_buffer_method m68hc11spi_io_read_buffer;
static hw_io_write_buffer_method m68hc11spi_io_write_buffer;
static hw_port_event_method m68hc11spi_port_event;
static hw_ioctl_method m68hc11spi_ioctl;
#define M6811_SPI_FIRST_REG (M6811_SPCR)
#define M6811_SPI_LAST_REG (M6811_SPDR)
static void
attach_m68hc11spi_regs (struct hw *me,
struct m68hc11spi *controller)
{
hw_attach_address (hw_parent (me), M6811_IO_LEVEL, io_map,
M6811_SPI_FIRST_REG,
M6811_SPI_LAST_REG - M6811_SPI_FIRST_REG + 1,
me);
}
static void
m68hc11spi_finish (struct hw *me)
{
struct m68hc11spi *controller;
controller = HW_ZALLOC (me, struct m68hc11spi);
set_hw_data (me, controller);
set_hw_io_read_buffer (me, m68hc11spi_io_read_buffer);
set_hw_io_write_buffer (me, m68hc11spi_io_write_buffer);
set_hw_ports (me, m68hc11spi_ports);
set_hw_port_event (me, m68hc11spi_port_event);
#ifdef set_hw_ioctl
set_hw_ioctl (me, m68hc11spi_ioctl);
#else
me->to_ioctl = m68hc11spi_ioctl;
#endif
/* Attach ourself to our parent bus. */
attach_m68hc11spi_regs (me, controller);
/* Initialize to reset state. */
controller->spi_event = NULL;
controller->rx_clear_scsr = 0;
}
/* An event arrives on an interrupt port */
static void
m68hc11spi_port_event (struct hw *me,
int my_port,
struct hw *source,
int source_port,
int level)
{
SIM_DESC sd;
struct m68hc11spi *controller;
sim_cpu *cpu;
unsigned8 val;
controller = hw_data (me);
sd = hw_system (me);
cpu = STATE_CPU (sd, 0);
switch (my_port)
{
case RESET_PORT:
{
HW_TRACE ((me, "SPI reset"));
/* Reset the state of SPI registers. */
controller->rx_clear_scsr = 0;
if (controller->spi_event)
{
hw_event_queue_deschedule (me, controller->spi_event);
controller->spi_event = 0;
}
val = 0;
m68hc11spi_io_write_buffer (me, &val, io_map,
(unsigned_word) M6811_SPCR, 1);
break;
}
default:
hw_abort (me, "Event on unknown port %d", my_port);
break;
}
}
static void
set_bit_port (struct hw *me, sim_cpu *cpu, int port, int mask, int value)
{
uint8 val;
if (value)
val = cpu->ios[port] | mask;
else
val = cpu->ios[port] & ~mask;
/* Set the new value and post an event to inform other devices
that pin 'port' changed. */
m68hc11cpu_set_port (me, cpu, port, val);
}
/* When a character is sent/received by the SPI, the PD2..PD5 line
are driven by the following signals:
B7 B6
-----+---------+--------+---/-+-------
MOSI | | | | | |
MISO +---------+--------+---/-+
____ ___
CLK _______/ \____/ \__ CPOL=0, CPHA=0
_______ ____ __
\____/ \___/ CPOL=1, CPHA=0
____ ____ __
__/ \____/ \___/ CPOL=0, CPHA=1
__ ____ ___
\____/ \____/ \__ CPOL=1, CPHA=1
SS ___ ____
\__________________________//___/
MISO = PD2
MOSI = PD3
SCK = PD4
SS = PD5
*/
#define SPI_START_BYTE 0
#define SPI_START_BIT 1
#define SPI_MIDDLE_BIT 2
static void
m68hc11spi_clock (struct hw *me, void *data)
{
SIM_DESC sd;
struct m68hc11spi* controller;
sim_cpu *cpu;
int check_interrupt = 0;
controller = hw_data (me);
sd = hw_system (me);
cpu = STATE_CPU (sd, 0);
/* Cleanup current event. */
if (controller->spi_event)
{
hw_event_queue_deschedule (me, controller->spi_event);
controller->spi_event = 0;
}
/* Change a bit of data at each two SPI event. */
if (controller->mode == SPI_START_BIT)
{
/* Reflect the bit value on bit 2 of port D. */
set_bit_port (me, cpu, M6811_PORTD, (1 << 2),
(controller->tx_char & (1 << controller->tx_bit)));
controller->tx_bit--;
controller->mode = SPI_MIDDLE_BIT;
}
else if (controller->mode == SPI_MIDDLE_BIT)
{
controller->mode = SPI_START_BIT;
}
if (controller->mode == SPI_START_BYTE)
{
/* Start a new SPI transfer. */
/* TBD: clear SS output. */
controller->mode = SPI_START_BIT;
controller->tx_bit = 7;
set_bit_port (me, cpu, M6811_PORTD, (1 << 4), ~controller->clk_pin);
}
else
{
/* Change the SPI clock at each event on bit 4 of port D. */
controller->clk_pin = ~controller->clk_pin;
set_bit_port (me, cpu, M6811_PORTD, (1 << 4), controller->clk_pin);
}
/* Transmit is now complete for this byte. */
if (controller->mode == SPI_START_BIT && controller->tx_bit < 0)
{
controller->rx_clear_scsr = 0;
cpu->ios[M6811_SPSR] |= M6811_SPIF;
if (cpu->ios[M6811_SPCR] & M6811_SPIE)
check_interrupt = 1;
}
else
{
controller->spi_event = hw_event_queue_schedule (me, controller->clock,
m68hc11spi_clock,
NULL);
}
if (check_interrupt)
interrupts_update_pending (&cpu->cpu_interrupts);
}
/* Flags of the SPCR register. */
io_reg_desc spcr_desc[] = {
{ M6811_SPIE, "SPIE ", "Serial Peripheral Interrupt Enable" },
{ M6811_SPE, "SPE ", "Serial Peripheral System Enable" },
{ M6811_DWOM, "DWOM ", "Port D Wire-OR mode option" },
{ M6811_MSTR, "MSTR ", "Master Mode Select" },
{ M6811_CPOL, "CPOL ", "Clock Polarity" },
{ M6811_CPHA, "CPHA ", "Clock Phase" },
{ M6811_SPR1, "SPR1 ", "SPI Clock Rate Select" },
{ M6811_SPR0, "SPR0 ", "SPI Clock Rate Select" },
{ 0, 0, 0 }
};
/* Flags of the SPSR register. */
io_reg_desc spsr_desc[] = {
{ M6811_SPIF, "SPIF ", "SPI Transfer Complete flag" },
{ M6811_WCOL, "WCOL ", "Write Collision" },
{ M6811_MODF, "MODF ", "Mode Fault" },
{ 0, 0, 0 }
};
static void
m68hc11spi_info (struct hw *me)
{
SIM_DESC sd;
uint16 base = 0;
sim_cpu *cpu;
struct m68hc11spi *controller;
uint8 val;
sd = hw_system (me);
cpu = STATE_CPU (sd, 0);
controller = hw_data (me);
sim_io_printf (sd, "M68HC11 SPI:\n");
base = cpu_get_io_base (cpu);
val = cpu->ios[M6811_SPCR];
print_io_byte (sd, "SPCR", spcr_desc, val, base + M6811_SPCR);
sim_io_printf (sd, "\n");
val = cpu->ios[M6811_SPSR];
print_io_byte (sd, "SPSR", spsr_desc, val, base + M6811_SPSR);
sim_io_printf (sd, "\n");
if (controller->spi_event)
{
signed64 t;
sim_io_printf (sd, " SPI has %d bits to send\n",
controller->tx_bit + 1);
t = hw_event_remain_time (me, controller->spi_event);
sim_io_printf (sd, " SPI current bit-cycle finished in %s\n",
cycle_to_string (cpu, t, PRINT_TIME | PRINT_CYCLE));
t += (controller->tx_bit + 1) * 2 * controller->clock;
sim_io_printf (sd, " SPI operation finished in %s\n",
cycle_to_string (cpu, t, PRINT_TIME | PRINT_CYCLE));
}
}
static int
m68hc11spi_ioctl (struct hw *me,
hw_ioctl_request request,
va_list ap)
{
m68hc11spi_info (me);
return 0;
}
/* generic read/write */
static unsigned
m68hc11spi_io_read_buffer (struct hw *me,
void *dest,
int space,
unsigned_word base,
unsigned nr_bytes)
{
SIM_DESC sd;
struct m68hc11spi *controller;
sim_cpu *cpu;
unsigned8 val;
HW_TRACE ((me, "read 0x%08lx %d", (long) base, (int) nr_bytes));
sd = hw_system (me);
cpu = STATE_CPU (sd, 0);
controller = hw_data (me);
switch (base)
{
case M6811_SPSR:
controller->rx_clear_scsr = cpu->ios[M6811_SCSR]
& (M6811_SPIF | M6811_WCOL | M6811_MODF);
case M6811_SPCR:
val = cpu->ios[base];
break;
case M6811_SPDR:
if (controller->rx_clear_scsr)
{
cpu->ios[M6811_SPSR] &= ~controller->rx_clear_scsr;
controller->rx_clear_scsr = 0;
interrupts_update_pending (&cpu->cpu_interrupts);
}
val = controller->rx_char;
break;
default:
return 0;
}
*((unsigned8*) dest) = val;
return 1;
}
static unsigned
m68hc11spi_io_write_buffer (struct hw *me,
const void *source,
int space,
unsigned_word base,
unsigned nr_bytes)
{
SIM_DESC sd;
struct m68hc11spi *controller;
sim_cpu *cpu;
unsigned8 val;
HW_TRACE ((me, "write 0x%08lx %d", (long) base, (int) nr_bytes));
sd = hw_system (me);
cpu = STATE_CPU (sd, 0);
controller = hw_data (me);
val = *((const unsigned8*) source);
switch (base)
{
case M6811_SPCR:
cpu->ios[M6811_SPCR] = val;
/* The SPI clock rate is 2, 4, 16, 32 of the internal CPU clock.
We have to drive the clock pin and need a 2x faster clock. */
switch (val & (M6811_SPR1 | M6811_SPR0))
{
case 0:
controller->clock = 1;
break;
case 1:
controller->clock = 2;
break;
case 2:
controller->clock = 8;
break;
default:
controller->clock = 16;
break;
}
/* Set the clock pin. */
if ((val & M6811_CPOL)
&& (controller->spi_event == 0
|| ((val & M6811_CPHA) && controller->mode == 1)))
controller->clk_pin = 1;
else
controller->clk_pin = 0;
set_bit_port (me, cpu, M6811_PORTD, (1 << 4), controller->clk_pin);
break;
/* Can't write to SPSR. */
case M6811_SPSR:
break;
case M6811_SPDR:
if (!(cpu->ios[M6811_SPCR] & M6811_SPE))
{
return 0;
}
if (controller->rx_clear_scsr)
{
cpu->ios[M6811_SPSR] &= ~controller->rx_clear_scsr;
controller->rx_clear_scsr = 0;
interrupts_update_pending (&cpu->cpu_interrupts);
}
/* If transfer is taking place, a write to SPDR
generates a collision. */
if (controller->spi_event)
{
cpu->ios[M6811_SPSR] |= M6811_WCOL;
break;
}
/* Refuse the write if there was no read of SPSR. */
/* ???? TBD. */
/* Prepare to send a byte. */
controller->tx_char = val;
controller->mode = SPI_START_BYTE;
/* Toggle clock pin internal value when CPHA is 0 so that
it will really change in the middle of a bit. */
if (!(cpu->ios[M6811_SPCR] & M6811_CPHA))
controller->clk_pin = ~controller->clk_pin;
cpu->ios[M6811_SPDR] = val;
/* Activate transmission. */
m68hc11spi_clock (me, NULL);
break;
default:
return 0;
}
return nr_bytes;
}
const struct hw_descriptor dv_m68hc11spi_descriptor[] = {
{ "m68hc11spi", m68hc11spi_finish },
{ "m68hc12spi", m68hc11spi_finish },
{ NULL },
};