/* 16550 serial driver for gdbstub I/O * * Copyright (C) 2007 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 Licence * as published by the Free Software Foundation; either version * 2 of the Licence, 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/nmi.h> #include <asm/pgtable.h> #include <asm/system.h> #include <asm/gdb-stub.h> #include <asm/exceptions.h> #include <asm/serial-regs.h> #include <unit/serial.h> /* * initialise the GDB stub */ void gdbstub_io_init(void) { u16 tmp; /* set up the serial port */ GDBPORT_SERIAL_LCR = UART_LCR_WLEN8; /* 1N8 */ GDBPORT_SERIAL_FCR = (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); FLOWCTL_CLEAR(DTR); FLOWCTL_SET(RTS); gdbstub_io_set_baud(115200); /* we want to get serial receive interrupts */ XIRQxICR(GDBPORT_SERIAL_IRQ) = 0; tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); IVAR0 = EXCEP_IRQ_LEVEL0; set_intr_stub(EXCEP_IRQ_LEVEL0, gdbstub_io_rx_handler); XIRQxICR(GDBPORT_SERIAL_IRQ) &= ~GxICR_REQUEST; XIRQxICR(GDBPORT_SERIAL_IRQ) = GxICR_ENABLE | GxICR_LEVEL_0; tmp = XIRQxICR(GDBPORT_SERIAL_IRQ); GDBPORT_SERIAL_IER = UART_IER_RDI | UART_IER_RLSI; /* permit level 0 IRQs to take place */ asm volatile( " and %0,epsw \n" " or %1,epsw \n" : : "i"(~EPSW_IM), "i"(EPSW_IE | EPSW_IM_1) ); } /* * set up the GDB stub serial port baud rate timers */ void gdbstub_io_set_baud(unsigned baud) { unsigned value; u8 lcr; value = 18432000 / 16 / baud; lcr = GDBPORT_SERIAL_LCR; GDBPORT_SERIAL_LCR |= UART_LCR_DLAB; GDBPORT_SERIAL_DLL = value & 0xff; GDBPORT_SERIAL_DLM = (value >> 8) & 0xff; GDBPORT_SERIAL_LCR = lcr; } /* * wait for a character to come from the debugger */ int gdbstub_io_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: /* pull chars out of the buffer */ ix = gdbstub_rx_outp; barrier(); if (ix == gdbstub_rx_inp) { if (nonblock) return -EAGAIN; #ifdef CONFIG_MN10300_WD_TIMER watchdog_alert_counter = 0; #endif /* CONFIG_MN10300_WD_TIMER */ goto try_again; } ch = gdbstub_rx_buffer[ix++]; st = gdbstub_rx_buffer[ix++]; barrier(); 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; } } /* * send a character to the debugger */ void gdbstub_io_tx_char(unsigned char ch) { FLOWCTL_SET(DTR); LSR_WAIT_FOR(THRE); /* FLOWCTL_WAIT_FOR(CTS); */ if (ch == 0x0a) { GDBPORT_SERIAL_TX = 0x0d; LSR_WAIT_FOR(THRE); /* FLOWCTL_WAIT_FOR(CTS); */ } GDBPORT_SERIAL_TX = ch; FLOWCTL_CLEAR(DTR); } /* * send a character to the debugger */ void gdbstub_io_tx_flush(void) { LSR_WAIT_FOR(TEMT); LSR_WAIT_FOR(THRE); FLOWCTL_CLEAR(DTR); }