diff options
Diffstat (limited to 'arch/frv/kernel/gdb-io.c')
| -rw-r--r-- | arch/frv/kernel/gdb-io.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/arch/frv/kernel/gdb-io.c b/arch/frv/kernel/gdb-io.c new file mode 100644 index 0000000..c997bcc --- /dev/null +++ b/arch/frv/kernel/gdb-io.c @@ -0,0 +1,216 @@ +/* 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() */ |