/* 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() */