MIPS: Loongson: Add serial port support

This patch add serial port support for all of the existing loongson
family machines. most of the board specific part are put in serial.c,
and the base address of the serial ports are defined as macros in
machine.h for sharing it between serial.c and early_printk.c

Signed-off-by: Wu Zhangjin <[e-mail]>
Cc: Linux-MIPS <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: Zhang Le <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/loongson/common/Makefile

···
 # Early printk support
 #
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_SERIAL_8250) += serial.o

arch/mips/loongson/common/serial.c

···
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2007 Ralf Baechle ([e-mail])
+ *
+ * Copyright (C) 2009 Lemote, Inc.
+ * Author: Yan hua ([e-mail])
+ * Author: Wu Zhangjin ([e-mail])
+ */
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/serial_8250.h>
+
+#include <asm/bootinfo.h>
+
+#include <loongson.h>
+#include <machine.h>
+
+#define PORT(int)			\
+{								\
+	.irq		= int,					\
+	.uartclk	= 1843200,				\
+	.iobase		= (LOONGSON_UART_BASE - LOONGSON_PCIIO_BASE),\
+	.iotype		= UPIO_PORT,				\
+	.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,	\
+	.regshift	= 0,					\
+}
+
+#define PORT_M(int)				\
+{								\
+	.irq		= MIPS_CPU_IRQ_BASE + (int),		\
+	.uartclk	= 3686400,				\
+	.iotype		= UPIO_MEM,				\
+	.membase	= (void __iomem *)NULL,			\
+	.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,	\
+	.regshift	= 0,					\
+}
+
+static struct plat_serial8250_port uart8250_data[][2] = {
+	[MACH_LOONGSON_UNKNOWN]         {},
+	[MACH_LEMOTE_FL2E]              {PORT(4), {} },
+	[MACH_LEMOTE_FL2F]              {PORT(3), {} },
+	[MACH_LEMOTE_ML2F7]             {PORT_M(3), {} },
+	[MACH_LEMOTE_YL2F89]            {PORT_M(3), {} },
+	[MACH_DEXXON_GDIUM2F10]         {PORT_M(3), {} },
+	[MACH_LOONGSON_END]             {},
+};
+
+static struct platform_device uart8250_device = {
+	.name = "serial8250",
+	.id = PLAT8250_DEV_PLATFORM,
+	.dev = {
+		.platform_data = uart8250_data[LOONGSON_MACHTYPE],
+		},
+};
+
+static int __init serial_init(void)
+{
+	if (uart8250_data[LOONGSON_MACHTYPE][0].iotype == UPIO_MEM)
+		uart8250_data[LOONGSON_MACHTYPE][0].membase =
+			ioremap_nocache(LOONGSON_UART_BASE, 8);
+
+	platform_device_register(&uart8250_device);
+
+	return 0;
+}
+
+device_initcall(serial_init);