source: SVN/rincon/u-boot/cpu/leon3/serial.c @ 55

Last change on this file since 55 was 55, checked in by Tim Harvey, 3 years ago

rincon: added latest u-boot source

restored form server backup

Signed-off-by: Tim Harvey <tharvey@…>

File size: 3.3 KB
Line 
1/* GRLIB APBUART Serial controller driver
2 *
3 * (C) Copyright 2007
4 * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
5 *
6 * See file CREDITS for list of people who contributed to this
7 * project.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22 * MA 02111-1307 USA
23 *
24 */
25
26#include <common.h>
27#include <asm/processor.h>
28#include <asm/leon.h>
29#include <ambapp.h>
30
31DECLARE_GLOBAL_DATA_PTR;
32
33/* Force cache miss each time a serial controller reg is read */
34#define CACHE_BYPASS 1
35
36#ifdef CACHE_BYPASS
37#define READ_BYTE(var)  SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
38#define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
39#define READ_WORD(var)  SPARC_NOCACHE_READ((unsigned int)&(var))
40#define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
41#endif
42
43ambapp_dev_apbuart *leon3_apbuart = NULL;
44
45int serial_init(void)
46{
47        ambapp_apbdev apbdev;
48        unsigned int tmp;
49
50        /* find UART */
51        if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {
52
53                leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;
54
55                /* found apbuart, let's init...
56                 *
57                 * Set scaler / baud rate
58                 *
59                 * Receiver & transmitter enable
60                 */
61                leon3_apbuart->scaler = CFG_GRLIB_APBUART_SCALER;
62
63                /* Let bit 11 be unchanged (debug bit for GRMON) */
64                tmp = READ_WORD(leon3_apbuart->ctrl);
65
66                leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
67                                       LEON_REG_UART_CTRL_RE |
68                                       LEON_REG_UART_CTRL_TE);
69
70                return 0;
71        }
72        return -1;              /* didn't find hardware */
73}
74
75void serial_putc(const char c)
76{
77        if (c == '\n')
78                serial_putc_raw('\r');
79
80        serial_putc_raw(c);
81}
82
83void serial_putc_raw(const char c)
84{
85        if (!leon3_apbuart)
86                return;
87
88        /* Wait for last character to go. */
89        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;
90
91        /* Send data */
92        leon3_apbuart->data = c;
93
94#ifdef LEON_DEBUG
95        /* Wait for data to be sent */
96        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
97#endif
98}
99
100void serial_puts(const char *s)
101{
102        while (*s) {
103                serial_putc(*s++);
104        }
105}
106
107int serial_getc(void)
108{
109        if (!leon3_apbuart)
110                return 0;
111
112        /* Wait for a character to arrive. */
113        while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;
114
115        /* read data */
116        return READ_WORD(leon3_apbuart->data);
117}
118
119int serial_tstc(void)
120{
121        if (leon3_apbuart)
122                return (READ_WORD(leon3_apbuart->status) &
123                        LEON_REG_UART_STATUS_DR);
124        return 0;
125}
126
127/* set baud rate for uart */
128void serial_setbrg(void)
129{
130        /* update baud rate settings, read it from gd->baudrate */
131        unsigned int scaler;
132        if (leon3_apbuart && (gd->baudrate > 0)) {
133                scaler =
134                    (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
135                     5) / 10;
136                leon3_apbuart->scaler = scaler;
137        }
138        return;
139}
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