1 /* 2 * This program is free software; you can redistribute it and/or modify it 3 * under the terms of the GNU General Public License version 2 as published 4 * by the Free Software Foundation. 5 * 6 * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org> 7 */ 8 9 #include <linux/io.h> 10 #include <linux/serial_reg.h> 11 12 #include <asm/addrspace.h> 13 14 #define EARLY_UART_BASE 0x10000c00 15 16 #define UART_REG_RX 0x00 17 #define UART_REG_TX 0x04 18 #define UART_REG_IER 0x08 19 #define UART_REG_IIR 0x0c 20 #define UART_REG_FCR 0x10 21 #define UART_REG_LCR 0x14 22 #define UART_REG_MCR 0x18 23 #define UART_REG_LSR 0x1c 24 25 static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE); 26 27 static inline void uart_w32(u32 val, unsigned reg) 28 { 29 __raw_writel(val, uart_membase + reg); 30 } 31 32 static inline u32 uart_r32(unsigned reg) 33 { 34 return __raw_readl(uart_membase + reg); 35 } 36 37 void prom_putchar(unsigned char ch) 38 { 39 while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) 40 ; 41 uart_w32(ch, UART_REG_TX); 42 while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) 43 ; 44 } 45