From 4efba82d0e4059588f2b2fc0ac2576eaf37f1d22 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Sun, 20 Jan 2013 22:02:55 +0100 Subject: [PATCH 07/79] MIPS: ralink: adds early_printk support Add the code needed to make early printk work. Signed-off-by: John Crispin Signed-off-by: Gabor Juhos Patchwork: http://patchwork.linux-mips.org/patch/4897/ --- arch/mips/ralink/early_printk.c | 44 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 arch/mips/ralink/early_printk.c diff --git a/arch/mips/ralink/early_printk.c b/arch/mips/ralink/early_printk.c new file mode 100644 index 0000000..c4ae47e --- /dev/null +++ b/arch/mips/ralink/early_printk.c @@ -0,0 +1,44 @@ +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * Copyright (C) 2011-2012 Gabor Juhos + */ + +#include +#include + +#include + +#define EARLY_UART_BASE 0x10000c00 + +#define UART_REG_RX 0x00 +#define UART_REG_TX 0x04 +#define UART_REG_IER 0x08 +#define UART_REG_IIR 0x0c +#define UART_REG_FCR 0x10 +#define UART_REG_LCR 0x14 +#define UART_REG_MCR 0x18 +#define UART_REG_LSR 0x1c + +static __iomem void *uart_membase = (__iomem void *) KSEG1ADDR(EARLY_UART_BASE); + +static inline void uart_w32(u32 val, unsigned reg) +{ + __raw_writel(val, uart_membase + reg); +} + +static inline u32 uart_r32(unsigned reg) +{ + return __raw_readl(uart_membase + reg); +} + +void prom_putchar(unsigned char ch) +{ + while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) + ; + uart_w32(ch, UART_REG_TX); + while ((uart_r32(UART_REG_LSR) & UART_LSR_THRE) == 0) + ; +} -- 1.7.10.4