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;
+}