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 #define CHIPID_BASE 0x300004 17 #elif defined(CONFIG_SOC_MT7621) 18 #define EARLY_UART_BASE 0x1E000c00 19 #define CHIPID_BASE 0x1E000004 20 #else 21 #define EARLY_UART_BASE 0x10000c00 22 #define CHIPID_BASE 0x10000004 23 #endif 24 25 #define MT7628_CHIP_NAME1 0x20203832 26 27 #define UART_REG_TX 0x04 28 #define UART_REG_LSR 0x14 29 #define UART_REG_LSR_RT2880 0x1c 30 31 static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE); 32 static __iomem void *chipid_membase = (__iomem void *) KSEG1ADDR(CHIPID_BASE); 33 34 static inline void uart_w32(u32 val, unsigned reg) 35 { 36 __raw_writel(val, uart_membase + reg); 37 } 38 39 static inline u32 uart_r32(unsigned reg) 40 { 41 return __raw_readl(uart_membase + reg); 42 } 43 44 static inline int soc_is_mt7628(void) 45 { 46 return IS_ENABLED(CONFIG_SOC_MT7620) && 47 (__raw_readl(chipid_membase) == MT7628_CHIP_NAME1); 48 } 49 50 void prom_putchar(unsigned char ch) 51 { 52 if (IS_ENABLED(CONFIG_SOC_MT7621) || soc_is_mt7628()) { 53 uart_w32(ch, UART_TX); 54 while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) 55 ; 56 } else { 57 while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0) 58 ; 59 uart_w32(ch, UART_REG_TX); 60 while ((uart_r32(UART_REG_LSR_RT2880) & UART_LSR_THRE) == 0) 61 ; 62 } 63 } 64