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binutils-gdb/sim/lm32/dv-lm32uart.c

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/* Lattice Mico32 UART model.
Contributed by Jon Beniston <jon@beniston.com>
Copyright (C) 2009, 2010, 2011 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/>. */
#include "sim-main.h"
#include "hw-main.h"
#include "sim-assert.h"
#include <stdio.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, &reg))
hw_abort (me, "\"reg\" property must contain three addr/size entries");
hw_unit_address_to_attach_address (hw_parent (me),
&reg.address,
&attach_space, &attach_address, me);
uart->base = attach_address;
hw_unit_size_to_attach_size (hw_parent (me), &reg.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},
};
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