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1 /*
2 * (C) Copyright 2000
3 * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
4 *
5 * (C) Copyright 2004
6 * ARM Ltd.
7 * Philippe Robin, <philippe.robin@arm.com>
8 *
9 * See file CREDITS for list of people who contributed to this
10 * project.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * MA 02111-1307 USA
26 */
27
28 /* Simple U-Boot driver for the PrimeCell PL011 UARTs on the IntegratorCP */
29 /* Should be fairly simple to make it work with the PL010 as well */
30
31 #include <common.h>
32
33 #ifdef CFG_PL011_SERIAL
34
35 #include "serial_pl011.h"
36
37 #define IO_WRITE(addr, val) (*(volatile unsigned int *)(addr) = (val))
38 #define IO_READ(addr) (*(volatile unsigned int *)(addr))
39
40 /*
41 * IntegratorCP has two UARTs, use the first one, at 38400-8-N-1
42 * Versatile PB has four UARTs.
43 */
44
45 #define CONSOLE_PORT CONFIG_CONS_INDEX
46 #define baudRate CONFIG_BAUDRATE
47 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
48 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
49
50 static void pl011_putc (int portnum, char c);
51 static int pl011_getc (int portnum);
52 static int pl011_tstc (int portnum);
53
54
55 int serial_init (void)
56 {
57 unsigned int temp;
58 unsigned int divider;
59 unsigned int remainder;
60 unsigned int fraction;
61
62 /*
63 ** First, disable everything.
64 */
65 IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR, 0x0);
66
67 /*
68 ** Set baud rate
69 **
70 ** IBRD = UART_CLK / (16 * BAUD_RATE)
71 ** FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
72 */
73 temp = 16 * baudRate;
74 divider = CONFIG_PL011_CLOCK / temp;
75 remainder = CONFIG_PL011_CLOCK % temp;
76 temp = (8 * remainder) / baudRate;
77 fraction = (temp >> 1) + (temp & 1);
78
79 IO_WRITE (port[CONSOLE_PORT] + UART_PL011_IBRD, divider);
80 IO_WRITE (port[CONSOLE_PORT] + UART_PL011_FBRD, fraction);
81
82 /*
83 ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled.
84 */
85 IO_WRITE (port[CONSOLE_PORT] + UART_PL011_LCRH,
86 (UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN));
87
88 /*
89 ** Finally, enable the UART
90 */
91 IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR,
92 (UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
93 UART_PL011_CR_RXE));
94
95 return 0;
96 }
97
98 void serial_putc (const char c)
99 {
100 if (c == '\n')
101 pl011_putc (CONSOLE_PORT, '\r');
102
103 pl011_putc (CONSOLE_PORT, c);
104 }
105
106 void serial_puts (const char *s)
107 {
108 while (*s) {
109 serial_putc (*s++);
110 }
111 }
112
113 int serial_getc (void)
114 {
115 return pl011_getc (CONSOLE_PORT);
116 }
117
118 int serial_tstc (void)
119 {
120 return pl011_tstc (CONSOLE_PORT);
121 }
122
123 void serial_setbrg (void)
124 {
125 }
126
127 static void pl011_putc (int portnum, char c)
128 {
129 /* Wait until there is space in the FIFO */
130 while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_TXFF);
131
132 /* Send the character */
133 IO_WRITE (port[portnum] + UART_PL01x_DR, c);
134 }
135
136 static int pl011_getc (int portnum)
137 {
138 unsigned int data;
139
140 /* Wait until there is data in the FIFO */
141 while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_RXFE);
142
143 data = IO_READ (port[portnum] + UART_PL01x_DR);
144
145 /* Check for an error flag */
146 if (data & 0xFFFFFF00) {
147 /* Clear the error */
148 IO_WRITE (port[portnum] + UART_PL01x_ECR, 0xFFFFFFFF);
149 return -1;
150 }
151
152 return (int) data;
153 }
154
155 static int pl011_tstc (int portnum)
156 {
157 return !(IO_READ (port[portnum] + UART_PL01x_FR) &
158 UART_PL01x_FR_RXFE);
159 }
160
161 #endif