MIPS: Lantiq: Add initial support for Lantiq SoCs

Add initial support for Mips based SoCs made by Lantiq. This series will add
support for the XWAY family.

The series allows booting a minimal system using a initramfs or NOR. Missing
drivers and support for Amazon and GPON family will be provided in a later
series.

[Ralf: Remove some cargo cult programming and fixed formatting.]

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2252/
Patchwork: https://patchwork.linux-mips.org/patch/2371/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/lantiq/early_printk.c b/arch/mips/lantiq/early_printk.c
new file mode 100644
index 0000000..972e05f
--- /dev/null
+++ b/arch/mips/lantiq/early_printk.c
@@ -0,0 +1,33 @@
+/*
+ *  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) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/init.h>
+#include <linux/cpu.h>
+
+#include <lantiq.h>
+#include <lantiq_soc.h>
+
+/* no ioremap possible at this early stage, lets use KSEG1 instead  */
+#define LTQ_ASC_BASE	KSEG1ADDR(LTQ_ASC1_BASE_ADDR)
+#define ASC_BUF		1024
+#define LTQ_ASC_FSTAT	((u32 *)(LTQ_ASC_BASE + 0x0048))
+#define LTQ_ASC_TBUF	((u32 *)(LTQ_ASC_BASE + 0x0020))
+#define TXMASK		0x3F00
+#define TXOFFSET	8
+
+void prom_putchar(char c)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	do { } while ((ltq_r32(LTQ_ASC_FSTAT) & TXMASK) >> TXOFFSET);
+	if (c == '\n')
+		ltq_w32('\r', LTQ_ASC_TBUF);
+	ltq_w32(c, LTQ_ASC_TBUF);
+	local_irq_restore(flags);
+}