xref: /openbmc/u-boot/drivers/serial/mcfuart.c (revision f0ff885c)
1 /*
2  * (C) Copyright 2004-2007 Freescale Semiconductor, Inc.
3  * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  *
23  */
24 
25 /*
26  * Minimal serial functions needed to use one of the uart ports
27  * as serial console interface.
28  */
29 
30 #include <common.h>
31 
32 #ifdef CONFIG_MCFUART
33 
34 #include <asm/immap.h>
35 #include <asm/uart.h>
36 
37 DECLARE_GLOBAL_DATA_PTR;
38 
39 extern void uart_port_conf(void);
40 
41 int serial_init(void)
42 {
43 	volatile uart_t *uart;
44 	u32 counter;
45 
46 	uart = (volatile uart_t *)(CFG_UART_BASE);
47 
48 	uart_port_conf();
49 
50 	/* write to SICR: SIM2 = uart mode,dcd does not affect rx */
51 	uart->ucr = UART_UCR_RESET_RX;
52 	uart->ucr = UART_UCR_RESET_TX;
53 	uart->ucr = UART_UCR_RESET_ERROR;
54 	uart->ucr = UART_UCR_RESET_MR;
55 	__asm__("nop");
56 
57 	uart->uimr = 0;
58 
59 	/* write to CSR: RX/TX baud rate from timers */
60 	uart->ucsr = (UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK);
61 
62 	uart->umr = (UART_UMR_BC_8 | UART_UMR_PM_NONE);
63 	uart->umr = UART_UMR_SB_STOP_BITS_1;
64 
65 	/* Setting up BaudRate */
66 	counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
67 	counter = counter / gd->baudrate;
68 
69 	/* write to CTUR: divide counter upper byte */
70 	uart->ubg1 = (u8) ((counter & 0xff00) >> 8);
71 	/* write to CTLR: divide counter lower byte */
72 	uart->ubg2 = (u8) (counter & 0x00ff);
73 
74 	uart->ucr = (UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED);
75 
76 	return (0);
77 }
78 
79 void serial_putc(const char c)
80 {
81 	volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
82 
83 	if (c == '\n')
84 		serial_putc('\r');
85 
86 	/* Wait for last character to go. */
87 	while (!(uart->usr & UART_USR_TXRDY)) ;
88 
89 	uart->utb = c;
90 }
91 
92 void serial_puts(const char *s)
93 {
94 	while (*s) {
95 		serial_putc(*s++);
96 	}
97 }
98 
99 int serial_getc(void)
100 {
101 	volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
102 
103 	/* Wait for a character to arrive. */
104 	while (!(uart->usr & UART_USR_RXRDY)) ;
105 	return uart->urb;
106 }
107 
108 int serial_tstc(void)
109 {
110 	volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
111 
112 	return (uart->usr & UART_USR_RXRDY);
113 }
114 
115 void serial_setbrg(void)
116 {
117 	volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
118 	u32 counter;
119 
120 	counter = ((gd->bus_clk / gd->baudrate)) >> 5;
121 	counter++;
122 
123 	/* write to CTUR: divide counter upper byte */
124 	uart->ubg1 = ((counter & 0xff00) >> 8);
125 	/* write to CTLR: divide counter lower byte */
126 	uart->ubg2 = (counter & 0x00ff);
127 
128 	uart->ucr = UART_UCR_RESET_RX;
129 	uart->ucr = UART_UCR_RESET_TX;
130 
131 	uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
132 }
133 #endif				/* CONFIG_MCFUART */
134