4 * Hardcoded to UART 0 for now
5 * Speed and options also hardcoded to 115200 8N1
7 * Copyright (c) 2003 Thomas.Lange@corelatus.se
9 * See file CREDITS for list of people who contributed to this
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.
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.
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,
30 #include <asm/au1x00.h>
32 /******************************************************************************
34 * serial_init - initialize a channel
36 * This routine initializes the number of data bits, parity
37 * and set the selected baud rate. Interrupts are disabled.
38 * Set the modem control signals if the option is selected.
43 int serial_init (void)
45 volatile u32 *uart_fifoctl = (volatile u32*)(UART0_ADDR+UART_FCR);
46 volatile u32 *uart_enable = (volatile u32*)(UART0_ADDR+UART_ENABLE);
48 /* Enable clocks first */
49 *uart_enable = UART_EN_CE;
51 /* Then release reset */
52 /* Must release reset before setting other regs */
53 *uart_enable = UART_EN_CE|UART_EN_E;
55 /* Activate fifos, reset tx and rx */
56 /* Set tx trigger level to 12 */
57 *uart_fifoctl = UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|
58 UART_FCR_CLEAR_XMIT|UART_FCR_T_TRIGGER_12;
66 void serial_setbrg (void)
68 volatile u32 *uart_clk = (volatile u32*)(UART0_ADDR+UART_CLK);
69 volatile u32 *uart_lcr = (volatile u32*)(UART0_ADDR+UART_LCR);
70 volatile u32 *sys_powerctrl = (u32 *)SYS_POWERCTRL;
74 /* sd is system clock divisor */
75 /* see section 10.4.5 in au1550 datasheet */
76 sd = (*sys_powerctrl & 0x03) + 2;
78 /* calulate 2x baudrate and round */
79 divisorx2 = ((CONFIG_SYS_MIPS_TIMER_FREQ/(sd * 16 * CONFIG_BAUDRATE)));
82 divisorx2 = divisorx2 + 1;
84 *uart_clk = divisorx2 / 2;
86 /* Set parity, stop bits and word length to 8N1 */
87 *uart_lcr = UART_LCR_WLEN8;
90 void serial_putc (const char c)
92 volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
93 volatile u32 *uart_tx = (volatile u32*)(UART0_ADDR+UART_TX);
95 if (c == '\n') serial_putc ('\r');
97 /* Wait for fifo to shift out some bytes */
98 while((*uart_lsr&UART_LSR_THRE)==0);
103 void serial_puts (const char *s)
111 int serial_getc (void)
113 volatile u32 *uart_rx = (volatile u32*)(UART0_ADDR+UART_RX);
116 while (!serial_tstc());
122 int serial_tstc (void)
124 volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
126 if(*uart_lsr&UART_LSR_DR){