arch/mn10300/kernel/gdb-io-ttysm.c - maze/linux - Git at Google

 /* 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;
 	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 & (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;
 }
	/* 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;
	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 & (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;
	}