1 files changed, 36 insertions, 0 deletions

diff --git a/arch/mips/ath79/early_printk.c b/arch/mips/ath79/early_printk.c
new file mode 100644
index 000000000000..7499b0e9df26
--- /dev/null
+++ b/arch/mips/ath79/early_printk.c
@@ -0,0 +1,36 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X SoC early printk support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@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-ath79/ar71xx_regs.h>
+
+static inline void prom_wait_thre(void __iomem *base)
+{
+        u32 lsr;
+
+        do {
+                lsr = __raw_readl(base + UART_LSR * 4);
+                if (lsr & UART_LSR_THRE)
+                        break;
+        } while (1);
+}
+
+void prom_putchar(unsigned char ch)
+{
+        void __iomem *base = (void __iomem *)(KSEG1ADDR(AR71XX_UART_BASE));
+
+        prom_wait_thre(base);
+        __raw_writel(ch, base + UART_TX * 4);
+        prom_wait_thre(base);
+}