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 #ifdef CONFIG_SOC_RT288X 15 #define EARLY_UART_BASE 0x300c00 16 #else 17 #define EARLY_UART_BASE 0x10000c00 18 #endif 19 20 #define UART_REG_RX 0x00 21 #define UART_REG_TX 0x04 22 #define UART_REG_IER 0x08 23 #define UART_REG_IIR 0x0c 24 #define UART_REG_FCR 0x10 25 #define UART_REG_LCR 0x14 26 #define UART_REG_MCR 0x18 27 #define UART_REG_LSR 0x1c 28 29 static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE); 30 31 static inline void uart_w32(u32 val, unsigned reg) 32 { 33 __raw_writel(val, uart_membase + reg); 34 } 35 36 static inline u32 uart_r32(unsigned reg) 37 { 38 return __raw_readl(uart_membase + reg); 39 } 40 41 void prom_putchar(unsigned char ch) 42 { 43 while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) 44 ; 45 uart_w32(ch, UART_REG_TX); 46 while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) 47 ; 48 } 49