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[PATCH V3 07/10] MIPS: ralink: adds early_printk support

To: Ralf Baechle <ralf@linux-mips.org>
Subject: [PATCH V3 07/10] MIPS: ralink: adds early_printk support
From: John Crispin <blogic@openwrt.org>
Date: Thu, 31 Jan 2013 12:59:18 +0100
Cc: linux-mips@linux-mips.org, John Crispin <blogic@openwrt.org>
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Add the code needed to make early printk work.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 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 <juhosg@openwrt.org>
+ */
+
+#include <linux/io.h>
+#include <linux/serial_reg.h>
+
+#include <asm/addrspace.h>
+
+#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


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