--- /dev/null
+/*
+ * Ralink RT3662/RT3883 SoC early printk support
+ *
+ * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/serial_reg.h>
+
+#include <asm/addrspace.h>
+
+#include <asm/mach-ralink/rt3883_regs.h>
+
+#define UART_READ(r) \
+ __raw_readl((void __iomem *)(KSEG1ADDR(RT3883_UART1_BASE) + 4 * (r)))
+
+#define UART_WRITE(r, v) \
+ __raw_writel((v), (void __iomem *)(KSEG1ADDR(RT3883_UART1_BASE) + 4 * (r)))
+
+void prom_putchar(unsigned char ch)
+{
+ while (((UART_READ(RT3883_UART_REG_LSR)) & UART_LSR_THRE) == 0);
+ UART_WRITE(RT3883_UART_REG_TX, ch);
+ while (((UART_READ(RT3883_UART_REG_LSR)) & UART_LSR_THRE) == 0);
+}