xref: /linux/arch/mips/bcm63xx/early_printk.c (revision e7300d04bd0809eb7ea10a2ed8c729459f816e36)
1*e7300d04SMaxime Bizon /*
2*e7300d04SMaxime Bizon  * This file is subject to the terms and conditions of the GNU General Public
3*e7300d04SMaxime Bizon  * License.  See the file "COPYING" in the main directory of this archive
4*e7300d04SMaxime Bizon  * for more details.
5*e7300d04SMaxime Bizon  *
6*e7300d04SMaxime Bizon  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7*e7300d04SMaxime Bizon  */
8*e7300d04SMaxime Bizon 
9*e7300d04SMaxime Bizon #include <linux/init.h>
10*e7300d04SMaxime Bizon #include <bcm63xx_io.h>
11*e7300d04SMaxime Bizon #include <bcm63xx_regs.h>
12*e7300d04SMaxime Bizon 
13*e7300d04SMaxime Bizon static void __init wait_xfered(void)
14*e7300d04SMaxime Bizon {
15*e7300d04SMaxime Bizon 	unsigned int val;
16*e7300d04SMaxime Bizon 
17*e7300d04SMaxime Bizon 	/* wait for any previous char to be transmitted */
18*e7300d04SMaxime Bizon 	do {
19*e7300d04SMaxime Bizon 		val = bcm_uart0_readl(UART_IR_REG);
20*e7300d04SMaxime Bizon 		if (val & UART_IR_STAT(UART_IR_TXEMPTY))
21*e7300d04SMaxime Bizon 			break;
22*e7300d04SMaxime Bizon 	} while (1);
23*e7300d04SMaxime Bizon }
24*e7300d04SMaxime Bizon 
25*e7300d04SMaxime Bizon void __init prom_putchar(char c)
26*e7300d04SMaxime Bizon {
27*e7300d04SMaxime Bizon 	wait_xfered();
28*e7300d04SMaxime Bizon 	bcm_uart0_writel(c, UART_FIFO_REG);
29*e7300d04SMaxime Bizon 	wait_xfered();
30*e7300d04SMaxime Bizon }
31