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Diffstat (limited to 'arch/mn10300/kernel/gdb-io-ttysm.c')
-rw-r--r--arch/mn10300/kernel/gdb-io-ttysm.c299
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;
+}