321 lines
8 KiB
C
321 lines
8 KiB
C
/* Lattice Mico32 UART model.
|
|
Contributed by Jon Beniston <jon@beniston.com>
|
|
|
|
Copyright (C) 2009-2022 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
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 "sim-assert.h"
|
|
|
|
#include <stdio.h>
|
|
#include <sys/select.h>
|
|
#include <sys/time.h>
|
|
|
|
struct lm32uart
|
|
{
|
|
unsigned base; /* Base address of this UART. */
|
|
unsigned limit; /* Limit address of this UART. */
|
|
unsigned char rbr;
|
|
unsigned char thr;
|
|
unsigned char ier;
|
|
unsigned char iir;
|
|
unsigned char lcr;
|
|
unsigned char mcr;
|
|
unsigned char lsr;
|
|
unsigned char msr;
|
|
unsigned char div;
|
|
struct hw_event *event;
|
|
};
|
|
|
|
/* UART registers. */
|
|
|
|
#define LM32_UART_RBR 0x0
|
|
#define LM32_UART_THR 0x0
|
|
#define LM32_UART_IER 0x4
|
|
#define LM32_UART_IIR 0x8
|
|
#define LM32_UART_LCR 0xc
|
|
#define LM32_UART_MCR 0x10
|
|
#define LM32_UART_LSR 0x14
|
|
#define LM32_UART_MSR 0x18
|
|
#define LM32_UART_DIV 0x1c
|
|
|
|
#define LM32_UART_IER_RX_INT 0x1
|
|
#define LM32_UART_IER_TX_INT 0x2
|
|
|
|
#define MICOUART_IIR_TXRDY 0x2
|
|
#define MICOUART_IIR_RXRDY 0x4
|
|
|
|
#define LM32_UART_LSR_RX_RDY 0x01
|
|
#define LM32_UART_LSR_TX_RDY 0x20
|
|
|
|
#define LM32_UART_LCR_WLS_MASK 0x3
|
|
#define LM32_UART_LCR_WLS_5 0x0
|
|
#define LM32_UART_LCR_WLS_6 0x1
|
|
#define LM32_UART_LCR_WLS_7 0x2
|
|
#define LM32_UART_LCR_WLS_8 0x3
|
|
|
|
/* UART ports. */
|
|
|
|
enum
|
|
{
|
|
INT_PORT
|
|
};
|
|
|
|
static const struct hw_port_descriptor lm32uart_ports[] = {
|
|
{"int", INT_PORT, 0, output_port},
|
|
{}
|
|
};
|
|
|
|
static void
|
|
do_uart_tx_event (struct hw *me, void *data)
|
|
{
|
|
struct lm32uart *uart = hw_data (me);
|
|
char c;
|
|
|
|
/* Generate interrupt when transmission is complete. */
|
|
if (uart->ier & LM32_UART_IER_TX_INT)
|
|
{
|
|
/* Generate interrupt */
|
|
hw_port_event (me, INT_PORT, 1);
|
|
}
|
|
|
|
/* Indicate which interrupt has occured. */
|
|
uart->iir = MICOUART_IIR_TXRDY;
|
|
|
|
/* Indicate THR is empty. */
|
|
uart->lsr |= LM32_UART_LSR_TX_RDY;
|
|
|
|
/* Output the character in the THR. */
|
|
c = (char) uart->thr;
|
|
|
|
/* WLS field in LCR register specifies the number of bits to output. */
|
|
switch (uart->lcr & LM32_UART_LCR_WLS_MASK)
|
|
{
|
|
case LM32_UART_LCR_WLS_5:
|
|
c &= 0x1f;
|
|
break;
|
|
case LM32_UART_LCR_WLS_6:
|
|
c &= 0x3f;
|
|
break;
|
|
case LM32_UART_LCR_WLS_7:
|
|
c &= 0x7f;
|
|
break;
|
|
}
|
|
printf ("%c", c);
|
|
}
|
|
|
|
static unsigned
|
|
lm32uart_io_write_buffer (struct hw *me,
|
|
const void *source,
|
|
int space, unsigned_word base, unsigned nr_bytes)
|
|
{
|
|
struct lm32uart *uart = hw_data (me);
|
|
int uart_reg;
|
|
const unsigned char *source_bytes = source;
|
|
int value = 0;
|
|
|
|
HW_TRACE ((me, "write to 0x%08lx length %d with 0x%x", (long) base,
|
|
(int) nr_bytes, value));
|
|
|
|
if (nr_bytes == 4)
|
|
value = (source_bytes[0] << 24)
|
|
| (source_bytes[1] << 16) | (source_bytes[2] << 8) | (source_bytes[3]);
|
|
else
|
|
hw_abort (me, "write of unsupported number of bytes: %d.", nr_bytes);
|
|
|
|
uart_reg = base - uart->base;
|
|
|
|
switch (uart_reg)
|
|
{
|
|
case LM32_UART_THR:
|
|
/* Buffer the character to output. */
|
|
uart->thr = value;
|
|
|
|
/* Indicate the THR is full. */
|
|
uart->lsr &= ~LM32_UART_LSR_TX_RDY;
|
|
|
|
/* deassert interrupt when IER is loaded. */
|
|
uart->iir &= ~MICOUART_IIR_TXRDY;
|
|
|
|
/* schedule an event to output the character. */
|
|
hw_event_queue_schedule (me, 1, do_uart_tx_event, 0);
|
|
|
|
break;
|
|
case LM32_UART_IER:
|
|
uart->ier = value;
|
|
if ((value & LM32_UART_IER_TX_INT)
|
|
&& (uart->lsr & LM32_UART_LSR_TX_RDY))
|
|
{
|
|
/* hw_event_queue_schedule (me, 1, do_uart_tx_event, 0); */
|
|
uart->lsr |= LM32_UART_LSR_TX_RDY;
|
|
uart->iir |= MICOUART_IIR_TXRDY;
|
|
hw_port_event (me, INT_PORT, 1);
|
|
}
|
|
else if ((value & LM32_UART_IER_TX_INT) == 0)
|
|
{
|
|
hw_port_event (me, INT_PORT, 0);
|
|
}
|
|
break;
|
|
case LM32_UART_IIR:
|
|
uart->iir = value;
|
|
break;
|
|
case LM32_UART_LCR:
|
|
uart->lcr = value;
|
|
break;
|
|
case LM32_UART_MCR:
|
|
uart->mcr = value;
|
|
break;
|
|
case LM32_UART_LSR:
|
|
uart->lsr = value;
|
|
break;
|
|
case LM32_UART_MSR:
|
|
uart->msr = value;
|
|
break;
|
|
case LM32_UART_DIV:
|
|
uart->div = value;
|
|
break;
|
|
default:
|
|
hw_abort (me, "write to invalid register address: 0x%x.", uart_reg);
|
|
}
|
|
|
|
return nr_bytes;
|
|
}
|
|
|
|
static unsigned
|
|
lm32uart_io_read_buffer (struct hw *me,
|
|
void *dest,
|
|
int space, unsigned_word base, unsigned nr_bytes)
|
|
{
|
|
struct lm32uart *uart = hw_data (me);
|
|
int uart_reg;
|
|
int value;
|
|
unsigned char *dest_bytes = dest;
|
|
fd_set fd;
|
|
struct timeval tv;
|
|
|
|
HW_TRACE ((me, "read 0x%08lx length %d", (long) base, (int) nr_bytes));
|
|
|
|
uart_reg = base - uart->base;
|
|
|
|
switch (uart_reg)
|
|
{
|
|
case LM32_UART_RBR:
|
|
value = getchar ();
|
|
uart->lsr &= ~LM32_UART_LSR_RX_RDY;
|
|
break;
|
|
case LM32_UART_IER:
|
|
value = uart->ier;
|
|
break;
|
|
case LM32_UART_IIR:
|
|
value = uart->iir;
|
|
break;
|
|
case LM32_UART_LCR:
|
|
value = uart->lcr;
|
|
break;
|
|
case LM32_UART_MCR:
|
|
value = uart->mcr;
|
|
break;
|
|
case LM32_UART_LSR:
|
|
/* Check to see if any data waiting in stdin. */
|
|
FD_ZERO (&fd);
|
|
FD_SET (fileno (stdin), &fd);
|
|
tv.tv_sec = 0;
|
|
tv.tv_usec = 1;
|
|
if (select (fileno (stdin) + 1, &fd, NULL, NULL, &tv))
|
|
uart->lsr |= LM32_UART_LSR_RX_RDY;
|
|
value = uart->lsr;
|
|
break;
|
|
case LM32_UART_MSR:
|
|
value = uart->msr;
|
|
break;
|
|
case LM32_UART_DIV:
|
|
value = uart->div;
|
|
break;
|
|
default:
|
|
hw_abort (me, "read from invalid register address: 0x%x.", uart_reg);
|
|
}
|
|
|
|
if (nr_bytes == 4)
|
|
{
|
|
dest_bytes[0] = value >> 24;
|
|
dest_bytes[1] = value >> 16;
|
|
dest_bytes[2] = value >> 8;
|
|
dest_bytes[3] = value;
|
|
}
|
|
else
|
|
hw_abort (me, "read of unsupported number of bytes: %d", nr_bytes);
|
|
|
|
return nr_bytes;
|
|
}
|
|
|
|
static void
|
|
attach_lm32uart_regs (struct hw *me, struct lm32uart *uart)
|
|
{
|
|
unsigned_word attach_address;
|
|
int attach_space;
|
|
unsigned attach_size;
|
|
reg_property_spec reg;
|
|
|
|
if (hw_find_property (me, "reg") == NULL)
|
|
hw_abort (me, "Missing \"reg\" property");
|
|
if (!hw_find_reg_array_property (me, "reg", 0, ®))
|
|
hw_abort (me, "\"reg\" property must contain three addr/size entries");
|
|
hw_unit_address_to_attach_address (hw_parent (me),
|
|
®.address,
|
|
&attach_space, &attach_address, me);
|
|
uart->base = attach_address;
|
|
hw_unit_size_to_attach_size (hw_parent (me), ®.size, &attach_size, me);
|
|
uart->limit = attach_address + (attach_size - 1);
|
|
hw_attach_address (hw_parent (me),
|
|
0, attach_space, attach_address, attach_size, me);
|
|
}
|
|
|
|
static void
|
|
lm32uart_finish (struct hw *me)
|
|
{
|
|
struct lm32uart *uart;
|
|
int i;
|
|
|
|
uart = HW_ZALLOC (me, struct lm32uart);
|
|
set_hw_data (me, uart);
|
|
set_hw_io_read_buffer (me, lm32uart_io_read_buffer);
|
|
set_hw_io_write_buffer (me, lm32uart_io_write_buffer);
|
|
set_hw_ports (me, lm32uart_ports);
|
|
|
|
/* Attach ourself to our parent bus. */
|
|
attach_lm32uart_regs (me, uart);
|
|
|
|
/* Initialize the UART. */
|
|
uart->rbr = 0;
|
|
uart->thr = 0;
|
|
uart->ier = 0;
|
|
uart->iir = 0;
|
|
uart->lcr = 0;
|
|
uart->mcr = 0;
|
|
uart->lsr = LM32_UART_LSR_TX_RDY;
|
|
uart->msr = 0;
|
|
uart->div = 0; /* By setting to zero, characters are output immediately. */
|
|
}
|
|
|
|
const struct hw_descriptor dv_lm32uart_descriptor[] = {
|
|
{"lm32uart", lm32uart_finish,},
|
|
{NULL},
|
|
};
|