puts.c

LINUX 2.6.17.4的源码

/*
 *
 * BRIEF MODULE DESCRIPTION
 *	Low level uart routines to directly access a 16550 uart.
 *
 * Copyright 2000,2001 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *         	[e-mail] or [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/types.h>

#define SERIAL_BASE   0xB4011800	/* it8172 */
#define SER_CMD       5
#define SER_DATA      0x00
#define TX_BUSY       0x20

#define TIMEOUT       0xffff
#undef SLOW_DOWN

static const char digits[16] = "0123456789abcdef";
static volatile unsigned char *const com1 = (unsigned char *) SERIAL_BASE;


#ifdef SLOW_DOWN
static inline void slow_down()
{
	int k;
	for (k = 0; k < 10000; k++);
}
#else
#define slow_down()
#endif

void putch(const unsigned char c)
{
	unsigned char ch;
	int i = 0;

	do {
		ch = com1[SER_CMD];
		slow_down();
		i++;
		if (i > TIMEOUT) {
			break;
		}
	} while (0 == (ch & TX_BUSY));
	com1[SER_DATA] = c;
}

void puts(unsigned char *cp)
{
	unsigned char ch;
	int i = 0;

	while (*cp) {
		do {
			ch = com1[SER_CMD];
			slow_down();
			i++;
			if (i > TIMEOUT) {
				break;
			}
		} while (0 == (ch & TX_BUSY));
		com1[SER_DATA] = *cp++;
	}
	putch('\r');
	putch('\n');
}

void fputs(unsigned char *cp)
{
	unsigned char ch;
	int i = 0;

	while (*cp) {

		do {
			ch = com1[SER_CMD];
			slow_down();
			i++;
			if (i > TIMEOUT) {
				break;
			}
		} while (0 == (ch & TX_BUSY));
		com1[SER_DATA] = *cp++;
	}
}


void put64(uint64_t ul)
{
	int cnt;
	unsigned ch;

	cnt = 16;		/* 16 nibbles in a 64 bit long */
	putch('0');
	putch('x');
	do {
		cnt--;
		ch = (unsigned char) (ul >> cnt * 4) & 0x0F;
		putch(digits[ch]);
	} while (cnt > 0);
}

void put32(unsigned u)
{
	int cnt;
	unsigned ch;

	cnt = 8;		/* 8 nibbles in a 32 bit long */
	putch('0');
	putch('x');
	do {
		cnt--;
		ch = (unsigned char) (u >> cnt * 4) & 0x0F;
		putch(digits[ch]);
	} while (cnt > 0);
}