MIPS: Loongson: Cleanup the serial port support

To share the same kernel image amon different machines we have added the
machtype command line support.

In the old serial port implementation the UART base address is hardcoded as
a macro in machine.h which breaks with machtype, so change that to discover
the address dynamically.  Also move the initialization of the UART base
address to uart_base.c to avoid remapping twice for early_printk.c and
serial.c.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/581/
Patchwork: http://patchwork.linux-mips.org/patch/682/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-loongson/loongson.h

@@ -31,6 +31,9 @@ extern void __init prom_init_memory(void);
 extern void __init prom_init_cmdline(void);
 extern void __init prom_init_machtype(void);
 extern void __init prom_init_env(void);
+extern unsigned long _loongson_uart_base;
+extern unsigned long uart8250_base[];
+extern void prom_init_uart_base(void);
 
 /* irq operation functions */
 extern void bonito_irqdispatch(void);

arch/mips/include/asm/mach-loongson/machine.h

@@ -13,8 +13,6 @@
 
 #ifdef CONFIG_LEMOTE_FULOONG2E
 
-#define LOONGSON_UART_BASE (LOONGSON_PCIIO_BASE + 0x3f8)
-
 #define LOONGSON_MACHTYPE MACH_LEMOTE_FL2E
 
 #endif

arch/mips/loongson/common/Makefile

@@ -3,7 +3,7 @@
 #
 
 obj-y += setup.o init.o cmdline.o env.o time.o reset.o irq.o \
-    pci.o bonito-irq.o mem.o machtype.o
+    pci.o bonito-irq.o mem.o machtype.o uart_base.o
 
 #
 # Early printk support

arch/mips/loongson/common/early_printk.c

@@ -12,7 +12,6 @@
 #include <linux/serial_reg.h>
 
 #include <loongson.h>
-#include <machine.h>
 
 #define PORT(base, offset) (u8 *)(base + offset)
 
@@ -28,10 +27,14 @@ static inline void serial_out(unsigned char *base, int offset, int value)
 
 void prom_putchar(char c)
 {
-	unsigned char *uart_base =
-		(unsigned char *) ioremap_nocache(LOONGSON_UART_BASE, 8);
+	int timeout;
+	unsigned char *uart_base;
 
-	while ((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0)
+	uart_base = (unsigned char *)_loongson_uart_base;
+	timeout = 1024;
+
+	while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) &&
+			(timeout-- > 0))
 		;
 
 	serial_out(uart_base, UART_TX, c);

arch/mips/loongson/common/init.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
+ * Copyright (C) 2009 Lemote Inc.
  * Author: Wu Zhangjin, wuzj@lemote.com
  *
  * This program is free software; you can redistribute  it and/or modify it
@@ -10,19 +10,22 @@
 
 #include <linux/bootmem.h>
 
-#include <asm/bootinfo.h>
-
 #include <loongson.h>
 
 void __init prom_init(void)
 {
-    /* init base address of io space */
+	/* init base address of io space */
 	set_io_port_base((unsigned long)
 		ioremap(LOONGSON_PCIIO_BASE, LOONGSON_PCIIO_SIZE));
 
 	prom_init_cmdline();
 	prom_init_env();
 	prom_init_memory();
+
+	/*init the uart base address */
+#if defined(CONFIG_EARLY_PRINTK) || defined(CONFIG_SERIAL_8250)
+	prom_init_uart_base();
+#endif
 }
 
 void __init prom_free_prom_memory(void)

arch/mips/loongson/common/serial.c

@@ -23,7 +23,6 @@
 {								\
 	.irq		= int,					\
 	.uartclk	= 1843200,				\
-	.iobase		= (LOONGSON_UART_BASE - LOONGSON_PCIIO_BASE),\
 	.iotype		= UPIO_PORT,				\
 	.flags		= UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,	\
 	.regshift	= 0,					\
@@ -52,20 +51,20 @@ static struct plat_serial8250_port uart8250_data[][2] = {
 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);
+	if (uart8250_data[mips_machtype][0].iotype == UPIO_MEM)
+		uart8250_data[mips_machtype][0].membase =
+			(void __iomem *)_loongson_uart_base;
+	else if (uart8250_data[mips_machtype][0].iotype == UPIO_PORT)
+		uart8250_data[mips_machtype][0].iobase =
+		    uart8250_base[mips_machtype] - LOONGSON_PCIIO_BASE;
 
-	platform_device_register(&uart8250_device);
+	uart8250_device.dev.platform_data = uart8250_data[mips_machtype];
 
-	return 0;
+	return platform_device_register(&uart8250_device);
 }
 
 device_initcall(serial_init);

arch/mips/loongson/common/uart_base.c

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2009 Lemote Inc.
+ * Author: Wu Zhangjin, wuzj@lemote.com
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <asm/bootinfo.h>
+
+#include <loongson.h>
+
+unsigned long __maybe_unused _loongson_uart_base;
+EXPORT_SYMBOL(_loongson_uart_base);
+
+unsigned long __maybe_unused uart8250_base[] = {
+	[MACH_LOONGSON_UNKNOWN]	0,
+	[MACH_LEMOTE_FL2E]	(LOONGSON_PCIIO_BASE + 0x3f8),
+	[MACH_LEMOTE_FL2F]	(LOONGSON_PCIIO_BASE + 0x2f8),
+	[MACH_LEMOTE_ML2F7]	(LOONGSON_LIO1_BASE + 0x3f8),
+	[MACH_LEMOTE_YL2F89]	(LOONGSON_LIO1_BASE + 0x3f8),
+	[MACH_DEXXON_GDIUM2F10]	(LOONGSON_LIO1_BASE + 0x3f8),
+	[MACH_LOONGSON_END]	0,
+};
+EXPORT_SYMBOL(uart8250_base);
+
+void __maybe_unused prom_init_uart_base(void)
+{
+	_loongson_uart_base =
+		(unsigned long)ioremap_nocache(uart8250_base[mips_machtype], 8);
+}