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1 /*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18 #include <common.h>
19
20 #ifdef CONFIG_ATMEL_USART
21 #include <asm/io.h>
22 #include <asm/arch/clk.h>
23 #include <asm/arch/memory-map.h>
24
25 #if defined(CONFIG_USART0)
26 # define USART_ID 0
27 # define USART_BASE USART0_BASE
28 #elif defined(CONFIG_USART1)
29 # define USART_ID 1
30 # define USART_BASE USART1_BASE
31 #elif defined(CONFIG_USART2)
32 # define USART_ID 2
33 # define USART_BASE USART2_BASE
34 #elif defined(CONFIG_USART3)
35 # define USART_ID 3
36 # define USART_BASE USART3_BASE
37 #endif
38
39 #include "atmel_usart.h"
40
41 DECLARE_GLOBAL_DATA_PTR;
42
43 void serial_setbrg(void)
44 {
45 unsigned long divisor;
46 unsigned long usart_hz;
47
48 /*
49 * Master Clock
50 * Baud Rate = --------------
51 * 16 * CD
52 */
53 usart_hz = get_usart_clk_rate(USART_ID);
54 divisor = (usart_hz / 16 + gd->baudrate / 2) / gd->baudrate;
55 usart3_writel(BRGR, USART3_BF(CD, divisor));
56 }
57
58 int serial_init(void)
59 {
60 usart3_writel(CR, USART3_BIT(RSTRX) | USART3_BIT(RSTTX));
61
62 serial_setbrg();
63
64 usart3_writel(CR, USART3_BIT(RXEN) | USART3_BIT(TXEN));
65 usart3_writel(MR, (USART3_BF(USART_MODE, USART3_USART_MODE_NORMAL)
66 | USART3_BF(USCLKS, USART3_USCLKS_MCK)
67 | USART3_BF(CHRL, USART3_CHRL_8)
68 | USART3_BF(PAR, USART3_PAR_NONE)
69 | USART3_BF(NBSTOP, USART3_NBSTOP_1)));
70
71 return 0;
72 }
73
74 void serial_putc(char c)
75 {
76 if (c == '\n')
77 serial_putc('\r');
78
79 while (!(usart3_readl(CSR) & USART3_BIT(TXRDY))) ;
80 usart3_writel(THR, c);
81 }
82
83 void serial_puts(const char *s)
84 {
85 while (*s)
86 serial_putc(*s++);
87 }
88
89 int serial_getc(void)
90 {
91 while (!(usart3_readl(CSR) & USART3_BIT(RXRDY))) ;
92 return usart3_readl(RHR);
93 }
94
95 int serial_tstc(void)
96 {
97 return (usart3_readl(CSR) & USART3_BIT(RXRDY)) != 0;
98 }
99
100 #endif /* CONFIG_ATMEL_USART */