xref: /openbmc/u-boot/drivers/serial/altera_uart.c (revision f51cdaf1)
1 /*
2  * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
3  * Scott McNutt <smcnutt@psyent.com>
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 
25 #include <common.h>
26 #include <watchdog.h>
27 #include <asm/io.h>
28 #include <nios2-io.h>
29 
30 DECLARE_GLOBAL_DATA_PTR;
31 
32 /*------------------------------------------------------------------
33  * UART the serial port
34  *-----------------------------------------------------------------*/
35 
36 static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
37 
38 #if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
39 
40 /* Everything's already setup for fixed-baud PTF
41  * assignment
42  */
43 void serial_setbrg (void){ return; }
44 int serial_init (void) { return (0);}
45 
46 #else
47 
48 void serial_setbrg (void)
49 {
50 	unsigned div;
51 
52 	div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
53 	writel (div, &uart->divisor);
54 	return;
55 }
56 
57 int serial_init (void)
58 {
59 	serial_setbrg ();
60 	return (0);
61 }
62 
63 #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
64 
65 /*-----------------------------------------------------------------------
66  * UART CONSOLE
67  *---------------------------------------------------------------------*/
68 void serial_putc (char c)
69 {
70 	if (c == '\n')
71 		serial_putc ('\r');
72 	while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
73 		WATCHDOG_RESET ();
74 	writel ((unsigned char)c, &uart->txdata);
75 }
76 
77 void serial_puts (const char *s)
78 {
79 	while (*s != 0) {
80 		serial_putc (*s++);
81 	}
82 }
83 
84 int serial_tstc (void)
85 {
86 	return (readl (&uart->status) & NIOS_UART_RRDY);
87 }
88 
89 int serial_getc (void)
90 {
91 	while (serial_tstc () == 0)
92 		WATCHDOG_RESET ();
93 	return (readl (&uart->rxdata) & 0x00ff );
94 }
95