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altera_uart.c 2.24 KiB
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  • /*
     * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
     * Scott McNutt <smcnutt@psyent.com>
     *
     * See file CREDITS for list of people who contributed to this
     * project.
     *
     * 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 program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * 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., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     */
    
    
    #include <common.h>
    #include <watchdog.h>
    #include <asm/io.h>
    #include <nios2-io.h>
    
    DECLARE_GLOBAL_DATA_PTR;
    
    /*------------------------------------------------------------------
     * UART the serial port
     *-----------------------------------------------------------------*/
    
    static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
    
    #if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
    
    /* Everything's already setup for fixed-baud PTF
     * assignment
     */
    void serial_setbrg (void){ return; }
    int serial_init (void) { return (0);}
    
    #else
    
    void serial_setbrg (void)
    {
    	unsigned div;
    
    	div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
    
    	writel (div, &uart->divisor);
    
    	return;
    }
    
    int serial_init (void)
    {
    	serial_setbrg ();
    	return (0);
    }
    
    #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
    
    /*-----------------------------------------------------------------------
     * UART CONSOLE
     *---------------------------------------------------------------------*/
    void serial_putc (char c)
    {
    	if (c == '\n')
    		serial_putc ('\r');
    	while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
    		WATCHDOG_RESET ();
    
    	writel ((unsigned char)c, &uart->txdata);
    
    }
    
    void serial_puts (const char *s)
    {
    	while (*s != 0) {
    		serial_putc (*s++);
    	}
    }
    
    int serial_tstc (void)
    {
    	return (readl (&uart->status) & NIOS_UART_RRDY);
    }
    
    int serial_getc (void)
    {
    	while (serial_tstc () == 0)
    		WATCHDOG_RESET ();
    	return (readl (&uart->rxdata) & 0x00ff );
    }