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/* gdb-io.c: FR403 GDB stub I/O
*
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/serial_reg.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/irc-regs.h>
#include <asm/timer-regs.h>
#include <asm/gdb-stub.h>
#include "gdb-io.h"
#ifdef CONFIG_GDBSTUB_UART0
#define __UART(X) (*(volatile uint8_t *)(UART0_BASE + (UART_##X)))
#define __UART_IRR_NMI 0xff0f0000
#else /* CONFIG_GDBSTUB_UART1 */
#define __UART(X) (*(volatile uint8_t *)(UART1_BASE + (UART_##X)))
#define __UART_IRR_NMI 0xfff00000
#endif
#define LSR_WAIT_FOR(STATE) \
do { \
gdbstub_do_rx(); \
} while (!(__UART(LSR) & UART_LSR_##STATE))
#define FLOWCTL_QUERY(LINE) ({ __UART(MSR) & UART_MSR_##LINE; })
#define FLOWCTL_CLEAR(LINE) do { __UART(MCR) &= ~UART_MCR_##LINE; mb(); } while (0)
#define FLOWCTL_SET(LINE) do { __UART(MCR) |= UART_MCR_##LINE; mb(); } while (0)
#define FLOWCTL_WAIT_FOR(LINE) \
do { \
gdbstub_do_rx(); \
} while(!FLOWCTL_QUERY(LINE))
/*****************************************************************************/
/*
* initialise the GDB stub
* - called with PSR.ET==0, so can't incur external interrupts
*/
void gdbstub_io_init(void)
{
/* set up the serial port */
__UART(LCR) = UART_LCR_WLEN8; /* 1N8 */
__UART(FCR) =
UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT |
UART_FCR_TRIGGER_1;
FLOWCTL_CLEAR(DTR);
FLOWCTL_SET(RTS);
// gdbstub_set_baud(115200);
/* we want to get serial receive interrupts */
__UART(IER) = UART_IER_RDI | UART_IER_RLSI;
mb();
__set_IRR(6, __UART_IRR_NMI); /* map ERRs and UARTx to NMI */
} /* end gdbstub_io_init() */
/*****************************************************************************/
/*
* set up the GDB stub serial port baud rate timers
*/
void gdbstub_set_baud(unsigned baud)
{
unsigned value, high, low;
u8 lcr;
/* work out the divisor to give us the nearest higher baud rate */
value = __serial_clock_speed_HZ / 16 / baud;
/* determine the baud rate range */
high = __serial_clock_speed_HZ / 16 / value;
low = __serial_clock_speed_HZ / 16 / (value + 1);
/* pick the nearest bound */
if (low + (high - low) / 2 > baud)
value++;
lcr = __UART(LCR);
__UART(LCR) |= UART_LCR_DLAB;
mb();
__UART(DLL) = value & 0xff;
__UART(DLM) = (value >> 8) & 0xff;
mb();
__UART(LCR) = lcr;
mb();
} /* end gdbstub_set_baud() */
/*****************************************************************************/
/*
* receive characters into the receive FIFO
*/
void gdbstub_do_rx(void)
{
unsigned ix, nix;
ix = gdbstub_rx_inp;
while (__UART(LSR) & UART_LSR_DR) {
nix = (ix + 2) & 0xfff;
if (nix == gdbstub_rx_outp)
break;
gdbstub_rx_buffer[ix++] = __UART(LSR);
gdbstub_rx_buffer[ix++] = __UART(RX);
ix = nix;
}
gdbstub_rx_inp = ix;
__clr_RC(15);
__clr_IRL();
} /* end gdbstub_do_rx() */
/*****************************************************************************/
/*
* wait for a character to come from the debugger
*/
int gdbstub_rx_char(unsigned char *_ch, int nonblock)
{
unsigned ix;
u8 ch, st;
*_ch = 0xff;
if (gdbstub_rx_unget) {
*_ch = gdbstub_rx_unget;
gdbstub_rx_unget = 0;
return 0;
}
try_again:
gdbstub_do_rx();
/* pull chars out of the buffer */
ix = gdbstub_rx_outp;
if (ix == gdbstub_rx_inp) {
if (nonblock)
return -EAGAIN;
//watchdog_alert_counter = 0;
goto try_again;
}
st = gdbstub_rx_buffer[ix++];
ch = gdbstub_rx_buffer[ix++];
gdbstub_rx_outp = ix & 0x00000fff;
if (st & UART_LSR_BI) {
gdbstub_proto("### GDB Rx Break Detected ###\n");
return -EINTR;
}
else if (st & (UART_LSR_FE|UART_LSR_OE|UART_LSR_PE)) {
gdbstub_proto("### GDB Rx Error (st=%02x) ###\n",st);
return -EIO;
}
else {
gdbstub_proto("### GDB Rx %02x (st=%02x) ###\n",ch,st);
*_ch = ch & 0x7f;
return 0;
}
} /* end gdbstub_rx_char() */
/*****************************************************************************/
/*
* send a character to the debugger
*/
void gdbstub_tx_char(unsigned char ch)
{
FLOWCTL_SET(DTR);
LSR_WAIT_FOR(THRE);
// FLOWCTL_WAIT_FOR(CTS);
if (ch == 0x0a) {
__UART(TX) = 0x0d;
mb();
LSR_WAIT_FOR(THRE);
// FLOWCTL_WAIT_FOR(CTS);
}
__UART(TX) = ch;
mb();
FLOWCTL_CLEAR(DTR);
} /* end gdbstub_tx_char() */
/*****************************************************************************/
/*
* send a character to the debugger
*/
void gdbstub_tx_flush(void)
{
LSR_WAIT_FOR(TEMT);
LSR_WAIT_FOR(THRE);
FLOWCTL_CLEAR(DTR);
} /* end gdbstub_tx_flush() */
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