2 * Copyright 2010, Renato Andreola <renato.andreola@imagos.it>
4 * See file CREDITS for list of people who contributed to this
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 #include <nios2-yanu.h>
28 DECLARE_GLOBAL_DATA_PTR;
30 /*-----------------------------------------------------------------*/
31 /* YANU Imagos serial port */
32 /*-----------------------------------------------------------------*/
34 static yanu_uart_t *uart = (yanu_uart_t *)CONFIG_SYS_NIOS_CONSOLE;
36 #if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
38 /* Everything's already setup for fixed-baud PTF assignment*/
40 void serial_setbrg (void)
43 const unsigned max_uns = 0xFFFFFFFF;
44 unsigned best_n, best_m, baud;
46 /* compute best N and M couple */
47 best_n = YANU_MAX_PRESCALER_N;
48 for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
49 if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
50 (unsigned)CONFIG_BAUDRATE) {
56 if ((unsigned)CONFIG_BAUDRATE <= (max_uns >> (15+n-k)))
60 ((unsigned)CONFIG_BAUDRATE * (1 << (15 + n - k))) /
61 ((unsigned)CONFIG_SYS_CLK_FREQ >> k);
63 baud = best_m + best_n * YANU_BAUDE;
64 writel(baud, &uart->baud);
71 void serial_setbrg (void)
74 const unsigned max_uns = 0xFFFFFFFF;
75 unsigned best_n, best_m, baud;
77 /* compute best N and M couple */
78 best_n = YANU_MAX_PRESCALER_N;
79 for (n = YANU_MAX_PRESCALER_N; n >= 0; n--) {
80 if ((unsigned)CONFIG_SYS_CLK_FREQ / (1 << (n + 4)) >=
87 if (gd->baudrate <= (max_uns >> (15+n-k)))
91 (gd->baudrate * (1 << (15 + n - k))) /
92 ((unsigned)CONFIG_SYS_CLK_FREQ >> k);
94 baud = best_m + best_n * YANU_BAUDE;
95 writel(baud, &uart->baud);
101 #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
103 int serial_init (void)
105 unsigned action,control;
107 /* status register cleanup */
108 action = YANU_ACTION_RRRDY |
114 YANU_ACTION_RFE | YANU_ACTION_RFIFO_CLEAR | YANU_ACTION_TFIFO_CLEAR;
116 writel(action, &uart->action);
118 /* control register cleanup */
119 /* no interrupts enabled */
121 /* hardware flow control disabled */
123 control = (0x7 << YANU_CONTROL_BITS_POS);
124 /* enven parity just to be clean */
125 control |= YANU_CONTROL_PAREVEN;
126 /* we set threshold for fifo */
127 control |= YANU_CONTROL_RDYDLY * YANU_RXFIFO_DLY;
128 control |= YANU_CONTROL_TXTHR * YANU_TXFIFO_THR;
130 writel(control, &uart->control);
132 /* to set baud rate */
139 /*-----------------------------------------------------------------------
141 *---------------------------------------------------------------------*/
142 void serial_putc (char c)
151 status = readl(&uart->status);
152 tx_chars = (status>>YANU_TFIFO_CHARS_POS)
153 & ((1<<YANU_TFIFO_CHARS_N)-1);
154 if (tx_chars < YANU_TXFIFO_SIZE-1)
159 writel((unsigned char)c, &uart->data);
162 void serial_puts (const char *s)
170 int serial_tstc(void)
174 status = readl(&uart->status);
175 return (((status >> YANU_RFIFO_CHARS_POS) &
176 ((1 << YANU_RFIFO_CHARS_N) - 1)) > 0);
179 int serial_getc (void)
181 while (serial_tstc() == 0)
184 /* first we pull the char */
185 writel(YANU_ACTION_RFIFO_PULL, &uart->action);
187 return(readl(&uart->data) & YANU_DATA_CHAR_MASK);