1 files changed, 299 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/gdb-io-ttysm.c b/arch/mn10300/kernel/gdb-io-ttysm.c
new file mode 100644
index 000000000000..c5451592d403
--- /dev/null
+++ b/arch/mn10300/kernel/gdb-io-ttysm.c
@@ -0,0 +1,299 @@
+/* MN10300 On-chip 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/tty.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/gdb-stub.h>
+#include <asm/exceptions.h>
+#include <asm/unit/clock.h>
+#include "mn10300-serial.h"
+
+#if defined(CONFIG_GDBSTUB_ON_TTYSM0)
+struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif0;
+#elif defined(CONFIG_GDBSTUB_ON_TTYSM1)
+struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif1;
+#else
+struct mn10300_serial_port *const gdbstub_port = &mn10300_serial_port_sif2;
+#endif
+
+
+/*
+ * initialise the GDB stub I/O routines
+ */
+void __init gdbstub_io_init(void)
+{
+        uint16_t scxctr;
+        int tmp;
+
+        switch (gdbstub_port->clock_src) {
+        case MNSCx_CLOCK_SRC_IOCLK:
+                gdbstub_port->ioclk = MN10300_IOCLK;
+                break;
+
+#ifdef MN10300_IOBCLK
+        case MNSCx_CLOCK_SRC_IOBCLK:
+                gdbstub_port->ioclk = MN10300_IOBCLK;
+                break;
+#endif
+        default:
+                BUG();
+        }
+
+        /* set up the serial port */
+        gdbstub_io_set_baud(115200);
+
+        /* we want to get serial receive interrupts */
+        set_intr_level(gdbstub_port->rx_irq, GxICR_LEVEL_0);
+        set_intr_level(gdbstub_port->tx_irq, GxICR_LEVEL_0);
+        set_intr_stub(EXCEP_IRQ_LEVEL0, gdbstub_io_rx_handler);
+
+        *gdbstub_port->rx_icr |= GxICR_ENABLE;
+        tmp = *gdbstub_port->rx_icr;
+
+        /* enable the device */
+        scxctr = SC01CTR_CLN_8BIT;      /* 1N8 */
+        switch (gdbstub_port->div_timer) {
+        case MNSCx_DIV_TIMER_16BIT:
+                scxctr |= SC0CTR_CK_TM8UFLOW_8; /* == SC1CTR_CK_TM9UFLOW_8
+                                                   == SC2CTR_CK_TM10UFLOW_8 */
+                break;
+
+        case MNSCx_DIV_TIMER_8BIT:
+                scxctr |= SC0CTR_CK_TM2UFLOW_8;
+                break;
+        }
+
+        scxctr |= SC01CTR_TXE | SC01CTR_RXE;
+
+        *gdbstub_port->_control = scxctr;
+        tmp = *gdbstub_port->_control;
+
+        /* permit level 0 IRQs only */
+        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)
+{
+        const unsigned bits = 10; /* 1 [start] + 8 [data] + 0 [parity] +
+                                   * 1 [stop] */
+        unsigned long ioclk = gdbstub_port->ioclk;
+        unsigned xdiv, tmp;
+        uint16_t tmxbr;
+        uint8_t tmxmd;
+
+        if (!baud) {
+                baud = 9600;
+        } else if (baud == 134) {
+                baud = 269;     /* 134 is really 134.5 */
+                xdiv = 2;
+        }
+
+try_alternative:
+        xdiv = 1;
+
+        switch (gdbstub_port->div_timer) {
+        case MNSCx_DIV_TIMER_16BIT:
+                tmxmd = TM8MD_SRC_IOCLK;
+                tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 65535)
+                        goto timer_okay;
+
+                tmxmd = TM8MD_SRC_IOCLK_8;
+                tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 65535)
+                        goto timer_okay;
+
+                tmxmd = TM8MD_SRC_IOCLK_32;
+                tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 65535)
+                        goto timer_okay;
+
+                break;
+
+        case MNSCx_DIV_TIMER_8BIT:
+                tmxmd = TM2MD_SRC_IOCLK;
+                tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 255)
+                        goto timer_okay;
+
+                tmxmd = TM2MD_SRC_IOCLK_8;
+                tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 255)
+                        goto timer_okay;
+
+                tmxmd = TM2MD_SRC_IOCLK_32;
+                tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
+                if (tmp > 0 && tmp <= 255)
+                        goto timer_okay;
+                break;
+        }
+
+        /* as a last resort, if the quotient is zero, default to 9600 bps */
+        baud = 9600;
+        goto try_alternative;
+
+timer_okay:
+        gdbstub_port->uart.timeout = (2 * bits * HZ) / baud;
+        gdbstub_port->uart.timeout += HZ / 50;
+
+        /* set the timer to produce the required baud rate */
+        switch (gdbstub_port->div_timer) {
+        case MNSCx_DIV_TIMER_16BIT:
+                *gdbstub_port->_tmxmd = 0;
+                *gdbstub_port->_tmxbr = tmxbr;
+                *gdbstub_port->_tmxmd = TM8MD_INIT_COUNTER;
+                *gdbstub_port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
+                break;
+
+        case MNSCx_DIV_TIMER_8BIT:
+                *gdbstub_port->_tmxmd = 0;
+                *(volatile u8 *) gdbstub_port->_tmxbr = (u8)tmxbr;
+                *gdbstub_port->_tmxmd = TM2MD_INIT_COUNTER;
+                *gdbstub_port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
+                break;
+        }
+}
+
+/*
+ * 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 & (PAGE_SIZE - 1);
+
+        st &= SC01STR_RXF | SC01STR_RBF | SC01STR_FEF | SC01STR_PEF |
+                SC01STR_OEF;
+
+        /* deal with what we've got
+         * - note that the UART doesn't do BREAK-detection for us
+         */
+        if (st & SC01STR_FEF && ch == 0) {
+                switch (gdbstub_port->rx_brk) {
+                case 0: gdbstub_port->rx_brk = 1;       goto try_again;
+                case 1: gdbstub_port->rx_brk = 2;       goto try_again;
+                case 2:
+                        gdbstub_port->rx_brk = 3;
+                        gdbstub_proto("### GDB MNSERIAL Rx Break Detected"
+                                      " ###\n");
+                        return -EINTR;
+                default:
+                        goto try_again;
+                }
+        } else if (st & SC01STR_FEF) {
+                if (gdbstub_port->rx_brk)
+                        goto try_again;
+
+                gdbstub_proto("### GDB MNSERIAL Framing Error ###\n");
+                return -EIO;
+        } else if (st & SC01STR_OEF) {
+                if (gdbstub_port->rx_brk)
+                        goto try_again;
+
+                gdbstub_proto("### GDB MNSERIAL Overrun Error ###\n");
+                return -EIO;
+        } else if (st & SC01STR_PEF) {
+                if (gdbstub_port->rx_brk)
+                        goto try_again;
+
+                gdbstub_proto("### GDB MNSERIAL Parity Error ###\n");
+                return -EIO;
+        } else {
+                /* look for the tail-end char on a break run */
+                if (gdbstub_port->rx_brk == 3) {
+                        switch (ch) {
+                        case 0xFF:
+                        case 0xFE:
+                        case 0xFC:
+                        case 0xF8:
+                        case 0xF0:
+                        case 0xE0:
+                        case 0xC0:
+                        case 0x80:
+                        case 0x00:
+                                gdbstub_port->rx_brk = 0;
+                                goto try_again;
+                        default:
+                                break;
+                        }
+                }
+
+                gdbstub_port->rx_brk = 0;
+                gdbstub_io("### 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)
+{
+        while (*gdbstub_port->_status & SC01STR_TBF)
+                continue;
+
+        if (ch == 0x0a) {
+                *(u8 *) gdbstub_port->_txb = 0x0d;
+                while (*gdbstub_port->_status & SC01STR_TBF)
+                        continue;
+        }
+
+        *(u8 *) gdbstub_port->_txb = ch;
+}
+
+/*
+ * flush the transmission buffers
+ */
+void gdbstub_io_tx_flush(void)
+{
+        while (*gdbstub_port->_status & (SC01STR_TBF | SC01STR_TXF))
+                continue;
+}