1 files changed, 155 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/gdb-io-serial.c b/arch/mn10300/kernel/gdb-io-serial.c
new file mode 100644
index 000000000000..9a6d4e8ebe73
--- /dev/null
+++ b/arch/mn10300/kernel/gdb-io-serial.c
@@ -0,0 +1,155 @@
+/* 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 <asm/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;
+        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++];
+        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);
+}