ppc4xx_serial.c

来自「是关于linux2.5.1的完全源码」· C语言 代码 · 共 191 行

/*
 * linux/arch/ppc/kernel/ppc405_serial.c
 *
 * This is a fairly standard 165xx type device that will eventually
 * be merged with other similar processor/boards.	-- Dan
 *
 * BRIEF MODULE DESCRIPTION
 *	Console I/O support for Early kernel bringup. 
 *
 * Copyright 2000 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *         	[e-mail] or [e-mail]
 * 	   	[e-mail]
 *
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>

#if defined(CONFIG_IBM405GP) || defined(CONFIG_IBM405CR)

#ifdef CONFIG_KGDB
#include <asm/kgdb.h>
#include <linux/init.h>
#endif

#ifdef CONFIG_DEBUG_BRINGUP

#include <linux/console.h>

extern void ftr_reset_preferred_console(void);


static int ppc405_sercons_setup(struct console *co, char *options)
{
#ifdef CONFIG_UART0_DEBUG_CONSOLE
    volatile unsigned char *uart_dll  = (char *)0xef600300;
    volatile unsigned char *uart_fcr  = (char *)0xef600302;
    volatile unsigned char *uart_lcr  = (char *)0xef600303;
#endif

#ifdef CONFIG_UART1_DEBUG_CONSOLE
    volatile unsigned char *uart_dll  = (char *)0xef600400;
    volatile unsigned char *uart_fcr  = (char *)0xef600402;
    volatile unsigned char *uart_lcr  = (char *)0xef600403;
#endif

    *uart_lcr = *uart_lcr | 0x80;   /* DLAB on  */

/* ftr revisit - there is no config option for this
**  also see include/asm-ppc/ppc405_serial.h
**
** #define CONFIG_IBM405GP_INTERNAL_CLOCK
*/


#ifdef  CONFIG_IBM405GP_INTERNAL_CLOCK 
    /* ftr revisit
    ** why is bit 19 of chcr0 (0x1000) being set?
    */
    /* 0x2a results in data corruption, kgdb works with 0x28 */
    *uart_dll = 0x28;		    /* 9600 baud */
    _put_CHCR0((_get_CHCR0() & 0xffffe000) | 0x103e);
#else
    *uart_dll = 0x48;		    /* 9600 baud */
#endif
    *uart_lcr = *uart_lcr & 0x7f;   /* DLAB off */

    return 0;
}


/*
 * This is a bringup hack, writing directly to uart0 or uart1
 */

static void
ppc405_sercons_write(struct console *co, const char *ptr,
            unsigned nb)
{ 
    int i;

#ifdef CONFIG_UART0_DEBUG_CONSOLE
    volatile unsigned char *uart_xmit = (char *)0xef600300;
    volatile unsigned char *uart_lsr  = (char *)0xef600305;
#endif

#ifdef CONFIG_UART1_DEBUG_CONSOLE
    volatile unsigned char *uart_xmit = (char *)0xef600400;
    volatile unsigned char *uart_lsr  = (char *)0xef600405;
#endif

    for (i = 0; i < nb; ++i) {

	/* wait for transmit reg (possibly fifo) to empty */
	while ((*uart_lsr & 0x40) == 0)
	    ;

	*uart_xmit = (ptr[i] & 0xff);

	if (ptr[i] == '\n') {

	    /* add a carriage return */
	
	    /* wait for transmit reg (possibly fifo) to empty */
	    while ((*uart_lsr & 0x40) == 0)
		;

	    *uart_xmit = '\r';
	}
    }

    return;
}


static int
ppc405_sercons_read(struct console *co, char *ptr, unsigned nb)
{ 
#ifdef CONFIG_UART0_DEBUG_CONSOLE
    volatile unsigned char *uart_rcv  = (char *)0xef600300;
    volatile unsigned char *uart_lsr  = (char *)0xef600305;
#endif

#ifdef CONFIG_UART1_DEBUG_CONSOLE
    volatile unsigned char *uart_rcv  = (char *)0xef600400;
    volatile unsigned char *uart_lsr  = (char *)0xef600405;
#endif


    /* ftr revisit: not tested */

    if (nb == 0)
	return(0);

    if (!ptr)
	return(-1);

    /* wait for receive reg (possibly fifo) to contain data */
    while ((*uart_lsr & 0x01) == 0)
	;

    *ptr = *uart_rcv;

    return(1);
}

static struct console ppc405_sercons = {
	name:		"dbg_cons",
	write:		ppc405_console_write,
	setup:		ppc405_console_setup,
	flags:		CON_PRINTBUFFER,
	index:		-1,
};

void
register_debug_console(void)
{
	register_console(&ppc405_sercons); 
}

void
unregister_debug_console(void)
{
	unregister_console(&ppc405_sercons);
}

#endif	/* CONFIG_DEBUG_BRINGUP */

#endif	/* #if defined(CONFIG_IBM405GP) || defined(CONFIG_IBM405CR) */