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5c952cf0 | 1 | /* |
67c7189d RA |
2 | * Copyright 2010, Renato Andreola <renato.andreola@imagos.it> |
3 | * | |
5c952cf0 WD |
4 | * See file CREDITS for list of people who contributed to this |
5 | * project. | |
6 | * | |
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. | |
11 | * | |
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. | |
16 | * | |
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, | |
20 | * MA 02111-1307 USA | |
21 | */ | |
22 | ||
5c952cf0 WD |
23 | #include <common.h> |
24 | #include <watchdog.h> | |
c2ced000 | 25 | #include <asm/io.h> |
67c7189d | 26 | #include <nios2-yanu.h> |
5c952cf0 | 27 | |
d87080b7 WD |
28 | DECLARE_GLOBAL_DATA_PTR; |
29 | ||
67c7189d RA |
30 | /*-----------------------------------------------------------------*/ |
31 | /* YANU Imagos serial port */ | |
32 | /*-----------------------------------------------------------------*/ | |
33 | ||
34 | static yanu_uart_t *uart = (yanu_uart_t *)CONFIG_SYS_NIOS_CONSOLE; | |
35 | ||
36 | #if defined(CONFIG_SYS_NIOS_FIXEDBAUD) | |
37 | ||
38 | /* Everything's already setup for fixed-baud PTF assignment*/ | |
39 | ||
40 | void serial_setbrg (void) | |
41 | { | |
42 | int n, k; | |
43 | const unsigned max_uns = 0xFFFFFFFF; | |
44 | unsigned best_n, best_m, baud; | |
45 | ||
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) { | |
51 | best_n = n; | |
52 | break; | |
53 | } | |
54 | } | |
55 | for (k = 0;; k++) { | |
56 | if ((unsigned)CONFIG_BAUDRATE <= (max_uns >> (15+n-k))) | |
57 | break; | |
58 | } | |
59 | best_m = | |
60 | ((unsigned)CONFIG_BAUDRATE * (1 << (15 + n - k))) / | |
61 | ((unsigned)CONFIG_SYS_CLK_FREQ >> k); | |
62 | ||
63 | baud = best_m + best_n * YANU_BAUDE; | |
64 | writel(&uart->baud, baud); | |
65 | ||
66 | return; | |
67 | } | |
68 | ||
69 | #else | |
70 | ||
71 | void serial_setbrg (void) | |
72 | { | |
73 | int n, k; | |
74 | const unsigned max_uns = 0xFFFFFFFF; | |
75 | unsigned best_n, best_m, baud; | |
76 | ||
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)) >= | |
81 | gd->baudrate) { | |
82 | best_n = n; | |
83 | break; | |
84 | } | |
85 | } | |
86 | for (k = 0;; k++) { | |
87 | if (gd->baudrate <= (max_uns >> (15+n-k))) | |
88 | break; | |
89 | } | |
90 | best_m = | |
91 | (gd->baudrate * (1 << (15 + n - k))) / | |
92 | ((unsigned)CONFIG_SYS_CLK_FREQ >> k); | |
93 | ||
94 | baud = best_m + best_n * YANU_BAUDE; | |
95 | writel(&uart->baud, baud); | |
96 | ||
97 | return; | |
98 | } | |
99 | ||
100 | ||
101 | #endif /* CONFIG_SYS_NIOS_FIXEDBAUD */ | |
102 | ||
103 | int serial_init (void) | |
104 | { | |
105 | unsigned action,control; | |
106 | ||
107 | /* status register cleanup */ | |
108 | action = YANU_ACTION_RRRDY | | |
109 | YANU_ACTION_RTRDY | | |
110 | YANU_ACTION_ROE | | |
111 | YANU_ACTION_RBRK | | |
112 | YANU_ACTION_RFE | | |
113 | YANU_ACTION_RPE | | |
114 | YANU_ACTION_RFE | YANU_ACTION_RFIFO_CLEAR | YANU_ACTION_TFIFO_CLEAR; | |
115 | ||
116 | writel(&uart->action, action); | |
117 | ||
118 | /* control register cleanup */ | |
119 | /* no interrupts enabled */ | |
120 | /* one stop bit */ | |
121 | /* hardware flow control disabled */ | |
122 | /* 8 bits */ | |
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; | |
129 | ||
130 | writel(&uart->control, control); | |
131 | ||
132 | /* to set baud rate */ | |
133 | serial_setbrg(); | |
134 | ||
135 | return (0); | |
136 | } | |
137 | ||
138 | ||
139 | /*----------------------------------------------------------------------- | |
140 | * YANU CONSOLE | |
141 | *---------------------------------------------------------------------*/ | |
142 | void serial_putc (char c) | |
143 | { | |
144 | int tx_chars; | |
145 | unsigned status; | |
146 | ||
147 | if (c == '\n') | |
148 | serial_putc ('\r'); | |
149 | ||
150 | while (1) { | |
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) | |
155 | break; | |
156 | WATCHDOG_RESET (); | |
157 | } | |
158 | ||
159 | writel(&uart->data, (unsigned char)c); | |
160 | } | |
161 | ||
162 | void serial_puts (const char *s) | |
163 | { | |
164 | while (*s != 0) { | |
165 | serial_putc (*s++); | |
166 | } | |
167 | } | |
168 | ||
169 | ||
170 | int serial_tstc(void) | |
171 | { | |
172 | unsigned status ; | |
173 | ||
174 | status = readl(&uart->status); | |
175 | return (((status >> YANU_RFIFO_CHARS_POS) & | |
176 | ((1 << YANU_RFIFO_CHARS_N) - 1)) > 0); | |
177 | } | |
178 | ||
179 | int serial_getc (void) | |
180 | { | |
181 | while (serial_tstc() == 0) | |
182 | WATCHDOG_RESET (); | |
183 | ||
184 | /* first we pull the char */ | |
185 | writel(&uart->action, YANU_ACTION_RFIFO_PULL); | |
186 | ||
187 | return(readl(&uart->data) & YANU_DATA_CHAR_MASK); | |
188 | } |