MIPS: Loongson 1B: Add board support

Adds basic platform devices for Loongson 1B, including serial port,
ethernet, USB, RTC and interrupt handler.

The Loongson 1B UART is compatible with NS16550A, the Loongson 1B GMAC is
built around a Synopsys IP Core.

Use normal instead of enhanced descriptors.

Thanks to Giuseppe for updating the normal descriptor in stmmac driver.
Thanks to Zhao Zhang for implementing the RTC driver.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: wuzhangjin@gmail.com
Cc: zhzhl555@gmail.com
Cc: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4133/
Patchwork: https://patchwork.linux-mips.org/patch/4134/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

12 files changed, 679 insertions, 0 deletions

diff --git a/arch/mips/loongson1/Kconfig b/arch/mips/loongson1/Kconfig
new file mode 100644
index 000000000000..237fa214de9f
--- /dev/null
+++ b/arch/mips/loongson1/Kconfig
@@ -0,0 +1,21 @@
+if MACH_LOONGSON1
+
+choice
+	prompt "Machine Type"
+
+config LOONGSON1_LS1B
+	bool "Loongson LS1B board"
+	select CEVT_R4K
+	select CSRC_R4K
+	select SYS_HAS_CPU_LOONGSON1B
+	select DMA_NONCOHERENT
+	select BOOT_ELF32
+	select IRQ_CPU
+	select SYS_SUPPORTS_32BIT_KERNEL
+	select SYS_SUPPORTS_LITTLE_ENDIAN
+	select SYS_SUPPORTS_HIGHMEM
+	select SYS_HAS_EARLY_PRINTK
+
+endchoice
+
+endif # MACH_LOONGSON1
diff --git a/arch/mips/loongson1/Makefile b/arch/mips/loongson1/Makefile
new file mode 100644
index 000000000000..9719c75886f5
--- /dev/null
+++ b/arch/mips/loongson1/Makefile
@@ -0,0 +1,11 @@
+#
+# Common code for all Loongson 1 based systems
+#
+
+obj-$(CONFIG_MACH_LOONGSON1) += common/
+
+#
+# Loongson LS1B board
+#
+
+obj-$(CONFIG_LOONGSON1_LS1B)  += ls1b/
diff --git a/arch/mips/loongson1/Platform b/arch/mips/loongson1/Platform
new file mode 100644
index 000000000000..99bdefe627af
--- /dev/null
+++ b/arch/mips/loongson1/Platform
@@ -0,0 +1,7 @@
+cflags-$(CONFIG_CPU_LOONGSON1)  += \
+	$(call cc-option,-march=mips32r2,-mips32r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS32) \
+	-Wa,-mips32r2 -Wa,--trap
+
+platform-$(CONFIG_MACH_LOONGSON1)	+= loongson1/
+cflags-$(CONFIG_MACH_LOONGSON1)		+= -I$(srctree)/arch/mips/include/asm/mach-loongson1
+load-$(CONFIG_LOONGSON1_LS1B)		+= 0xffffffff80100000
diff --git a/arch/mips/loongson1/common/Makefile b/arch/mips/loongson1/common/Makefile
new file mode 100644
index 000000000000..b2797709ef5b
--- /dev/null
+++ b/arch/mips/loongson1/common/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for common code of loongson1 based machines.
+#
+
+obj-y	+= clock.o irq.o platform.o prom.o reset.o setup.o
diff --git a/arch/mips/loongson1/common/clock.c b/arch/mips/loongson1/common/clock.c
new file mode 100644
index 000000000000..2d98fb030596
--- /dev/null
+++ b/arch/mips/loongson1/common/clock.c
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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 <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <asm/clock.h>
+#include <asm/time.h>
+
+#include <loongson1.h>
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+
+struct clk *clk_get(struct device *dev, const char *name)
+{
+	struct clk *c;
+	struct clk *ret = NULL;
+
+	mutex_lock(&clocks_mutex);
+	list_for_each_entry(c, &clocks, node) {
+		if (!strcmp(c->name, name)) {
+			ret = c;
+			break;
+		}
+	}
+	mutex_unlock(&clocks_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_get);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+static void pll_clk_init(struct clk *clk)
+{
+	u32 pll;
+
+	pll = __raw_readl(LS1X_CLK_PLL_FREQ);
+	clk->rate = (12 + (pll & 0x3f)) * 33 / 2
+			+ ((pll >> 8) & 0x3ff) * 33 / 1024 / 2;
+	clk->rate *= 1000000;
+}
+
+static void cpu_clk_init(struct clk *clk)
+{
+	u32 pll, ctrl;
+
+	pll = clk_get_rate(clk->parent);
+	ctrl = __raw_readl(LS1X_CLK_PLL_DIV) & DIV_CPU;
+	clk->rate = pll / (ctrl >> DIV_CPU_SHIFT);
+}
+
+static void ddr_clk_init(struct clk *clk)
+{
+	u32 pll, ctrl;
+
+	pll = clk_get_rate(clk->parent);
+	ctrl = __raw_readl(LS1X_CLK_PLL_DIV) & DIV_DDR;
+	clk->rate = pll / (ctrl >> DIV_DDR_SHIFT);
+}
+
+static void dc_clk_init(struct clk *clk)
+{
+	u32 pll, ctrl;
+
+	pll = clk_get_rate(clk->parent);
+	ctrl = __raw_readl(LS1X_CLK_PLL_DIV) & DIV_DC;
+	clk->rate = pll / (ctrl >> DIV_DC_SHIFT);
+}
+
+static struct clk_ops pll_clk_ops = {
+	.init	= pll_clk_init,
+};
+
+static struct clk_ops cpu_clk_ops = {
+	.init	= cpu_clk_init,
+};
+
+static struct clk_ops ddr_clk_ops = {
+	.init	= ddr_clk_init,
+};
+
+static struct clk_ops dc_clk_ops = {
+	.init	= dc_clk_init,
+};
+
+static struct clk pll_clk = {
+	.name	= "pll",
+	.ops	= &pll_clk_ops,
+};
+
+static struct clk cpu_clk = {
+	.name	= "cpu",
+	.parent = &pll_clk,
+	.ops	= &cpu_clk_ops,
+};
+
+static struct clk ddr_clk = {
+	.name	= "ddr",
+	.parent = &pll_clk,
+	.ops	= &ddr_clk_ops,
+};
+
+static struct clk dc_clk = {
+	.name	= "dc",
+	.parent = &pll_clk,
+	.ops	= &dc_clk_ops,
+};
+
+int clk_register(struct clk *clk)
+{
+	mutex_lock(&clocks_mutex);
+	list_add(&clk->node, &clocks);
+	if (clk->ops->init)
+		clk->ops->init(clk);
+	mutex_unlock(&clocks_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_register);
+
+static struct clk *ls1x_clks[] = {
+	&pll_clk,
+	&cpu_clk,
+	&ddr_clk,
+	&dc_clk,
+};
+
+int __init ls1x_clock_init(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ls1x_clks); i++)
+		clk_register(ls1x_clks[i]);
+
+	return 0;
+}
+
+void __init plat_time_init(void)
+{
+	struct clk *clk;
+
+	/* Initialize LS1X clocks */
+	ls1x_clock_init();
+
+	/* setup mips r4k timer */
+	clk = clk_get(NULL, "cpu");
+	if (IS_ERR(clk))
+		panic("unable to get dc clock, err=%ld", PTR_ERR(clk));
+
+	mips_hpt_frequency = clk_get_rate(clk) / 2;
+}
diff --git a/arch/mips/loongson1/common/irq.c b/arch/mips/loongson1/common/irq.c
new file mode 100644
index 000000000000..41bc8ffe7bba
--- /dev/null
+++ b/arch/mips/loongson1/common/irq.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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/interrupt.h>
+#include <linux/irq.h>
+#include <asm/irq_cpu.h>
+
+#include <loongson1.h>
+#include <irq.h>
+
+#define LS1X_INTC_REG(n, x) \
+		((void __iomem *)KSEG1ADDR(LS1X_INTC_BASE + (n * 0x18) + (x)))
+
+#define LS1X_INTC_INTISR(n)		LS1X_INTC_REG(n, 0x0)
+#define LS1X_INTC_INTIEN(n)		LS1X_INTC_REG(n, 0x4)
+#define LS1X_INTC_INTSET(n)		LS1X_INTC_REG(n, 0x8)
+#define LS1X_INTC_INTCLR(n)		LS1X_INTC_REG(n, 0xc)
+#define LS1X_INTC_INTPOL(n)		LS1X_INTC_REG(n, 0x10)
+#define LS1X_INTC_INTEDGE(n)		LS1X_INTC_REG(n, 0x14)
+
+static void ls1x_irq_ack(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
+			| (1 << bit), LS1X_INTC_INTCLR(n));
+}
+
+static void ls1x_irq_mask(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			& ~(1 << bit), LS1X_INTC_INTIEN(n));
+}
+
+static void ls1x_irq_mask_ack(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			& ~(1 << bit), LS1X_INTC_INTIEN(n));
+	__raw_writel(__raw_readl(LS1X_INTC_INTCLR(n))
+			| (1 << bit), LS1X_INTC_INTCLR(n));
+}
+
+static void ls1x_irq_unmask(struct irq_data *d)
+{
+	unsigned int bit = (d->irq - LS1X_IRQ_BASE) & 0x1f;
+	unsigned int n = (d->irq - LS1X_IRQ_BASE) >> 5;
+
+	__raw_writel(__raw_readl(LS1X_INTC_INTIEN(n))
+			| (1 << bit), LS1X_INTC_INTIEN(n));
+}
+
+static struct irq_chip ls1x_irq_chip = {
+	.name		= "LS1X-INTC",
+	.irq_ack	= ls1x_irq_ack,
+	.irq_mask	= ls1x_irq_mask,
+	.irq_mask_ack	= ls1x_irq_mask_ack,
+	.irq_unmask	= ls1x_irq_unmask,
+};
+
+static void ls1x_irq_dispatch(int n)
+{
+	u32 int_status, irq;
+
+	/* Get pending sources, masked by current enables */
+	int_status = __raw_readl(LS1X_INTC_INTISR(n)) &
+			__raw_readl(LS1X_INTC_INTIEN(n));
+
+	if (int_status) {
+		irq = LS1X_IRQ(n, __ffs(int_status));
+		do_IRQ(irq);
+	}
+}
+
+asmlinkage void plat_irq_dispatch(void)
+{
+	unsigned int pending;
+
+	pending = read_c0_cause() & read_c0_status() & ST0_IM;
+
+	if (pending & CAUSEF_IP7)
+		do_IRQ(TIMER_IRQ);
+	else if (pending & CAUSEF_IP2)
+		ls1x_irq_dispatch(0); /* INT0 */
+	else if (pending & CAUSEF_IP3)
+		ls1x_irq_dispatch(1); /* INT1 */
+	else if (pending & CAUSEF_IP4)
+		ls1x_irq_dispatch(2); /* INT2 */
+	else if (pending & CAUSEF_IP5)
+		ls1x_irq_dispatch(3); /* INT3 */
+	else if (pending & CAUSEF_IP6)
+		ls1x_irq_dispatch(4); /* INT4 */
+	else
+		spurious_interrupt();
+
+}
+
+struct irqaction cascade_irqaction = {
+	.handler = no_action,
+	.name = "cascade",
+	.flags = IRQF_NO_THREAD,
+};
+
+static void __init ls1x_irq_init(int base)
+{
+	int n;
+
+	/* Disable interrupts and clear pending,
+	 * setup all IRQs as high level triggered
+	 */
+	for (n = 0; n < 4; n++) {
+		__raw_writel(0x0, LS1X_INTC_INTIEN(n));
+		__raw_writel(0xffffffff, LS1X_INTC_INTCLR(n));
+		__raw_writel(0xffffffff, LS1X_INTC_INTPOL(n));
+		/* set DMA0, DMA1 and DMA2 to edge trigger */
+		__raw_writel(n ? 0x0 : 0xe000, LS1X_INTC_INTEDGE(n));
+	}
+
+
+	for (n = base; n < LS1X_IRQS; n++) {
+		irq_set_chip_and_handler(n, &ls1x_irq_chip,
+					 handle_level_irq);
+	}
+
+	setup_irq(INT0_IRQ, &cascade_irqaction);
+	setup_irq(INT1_IRQ, &cascade_irqaction);
+	setup_irq(INT2_IRQ, &cascade_irqaction);
+	setup_irq(INT3_IRQ, &cascade_irqaction);
+}
+
+void __init arch_init_irq(void)
+{
+	mips_cpu_irq_init();
+	ls1x_irq_init(LS1X_IRQ_BASE);
+}
diff --git a/arch/mips/loongson1/common/platform.c b/arch/mips/loongson1/common/platform.c
new file mode 100644
index 000000000000..e92d59c4bd78
--- /dev/null
+++ b/arch/mips/loongson1/common/platform.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/phy.h>
+#include <linux/serial_8250.h>
+#include <linux/stmmac.h>
+#include <asm-generic/sizes.h>
+
+#include <loongson1.h>
+
+#define LS1X_UART(_id)						\
+	{							\
+		.mapbase	= LS1X_UART ## _id ## _BASE,	\
+		.irq		= LS1X_UART ## _id ## _IRQ,	\
+		.iotype		= UPIO_MEM,			\
+		.flags		= UPF_IOREMAP | UPF_FIXED_TYPE,	\
+		.type		= PORT_16550A,			\
+	}
+
+static struct plat_serial8250_port ls1x_serial8250_port[] = {
+	LS1X_UART(0),
+	LS1X_UART(1),
+	LS1X_UART(2),
+	LS1X_UART(3),
+	{},
+};
+
+struct platform_device ls1x_uart_device = {
+	.name		= "serial8250",
+	.id		= PLAT8250_DEV_PLATFORM,
+	.dev		= {
+		.platform_data = ls1x_serial8250_port,
+	},
+};
+
+void __init ls1x_serial_setup(void)
+{
+	struct clk *clk;
+	struct plat_serial8250_port *p;
+
+	clk = clk_get(NULL, "dc");
+	if (IS_ERR(clk))
+		panic("unable to get dc clock, err=%ld", PTR_ERR(clk));
+
+	for (p = ls1x_serial8250_port; p->flags != 0; ++p)
+		p->uartclk = clk_get_rate(clk);
+}
+
+/* Synopsys Ethernet GMAC */
+static struct resource ls1x_eth0_resources[] = {
+	[0] = {
+		.start	= LS1X_GMAC0_BASE,
+		.end	= LS1X_GMAC0_BASE + SZ_64K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.name	= "macirq",
+		.start	= LS1X_GMAC0_IRQ,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct stmmac_mdio_bus_data ls1x_mdio_bus_data = {
+	.bus_id		= 0,
+	.phy_mask	= 0,
+};
+
+static struct plat_stmmacenet_data ls1x_eth_data = {
+	.bus_id		= 0,
+	.phy_addr	= -1,
+	.mdio_bus_data	= &ls1x_mdio_bus_data,
+	.has_gmac	= 1,
+	.tx_coe		= 1,
+};
+
+struct platform_device ls1x_eth0_device = {
+	.name		= "stmmaceth",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(ls1x_eth0_resources),
+	.resource	= ls1x_eth0_resources,
+	.dev		= {
+		.platform_data = &ls1x_eth_data,
+	},
+};
+
+/* USB EHCI */
+static u64 ls1x_ehci_dmamask = DMA_BIT_MASK(32);
+
+static struct resource ls1x_ehci_resources[] = {
+	[0] = {
+		.start	= LS1X_EHCI_BASE,
+		.end	= LS1X_EHCI_BASE + SZ_32K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= LS1X_EHCI_IRQ,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+struct platform_device ls1x_ehci_device = {
+	.name		= "ls1x-ehci",
+	.id		= -1,
+	.num_resources	= ARRAY_SIZE(ls1x_ehci_resources),
+	.resource	= ls1x_ehci_resources,
+	.dev		= {
+		.dma_mask = &ls1x_ehci_dmamask,
+	},
+};
+
+/* Real Time Clock */
+struct platform_device ls1x_rtc_device = {
+	.name		= "ls1x-rtc",
+	.id		= -1,
+};
diff --git a/arch/mips/loongson1/common/prom.c b/arch/mips/loongson1/common/prom.c
new file mode 100644
index 000000000000..1f8e49f9886d
--- /dev/null
+++ b/arch/mips/loongson1/common/prom.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.com>
+ *
+ * Modified from arch/mips/pnx833x/common/prom.c.
+ *
+ * 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/serial_reg.h>
+#include <asm/bootinfo.h>
+
+#include <loongson1.h>
+#include <prom.h>
+
+int prom_argc;
+char **prom_argv, **prom_envp;
+unsigned long memsize, highmemsize;
+
+char *prom_getenv(char *envname)
+{
+	char **env = prom_envp;
+	int i;
+
+	i = strlen(envname);
+
+	while (*env) {
+		if (strncmp(envname, *env, i) == 0 && *(*env+i) == '=')
+			return *env + i + 1;
+		env++;
+	}
+
+	return 0;
+}
+
+static inline unsigned long env_or_default(char *env, unsigned long dfl)
+{
+	char *str = prom_getenv(env);
+	return str ? simple_strtol(str, 0, 0) : dfl;
+}
+
+void __init prom_init_cmdline(void)
+{
+	char *c = &(arcs_cmdline[0]);
+	int i;
+
+	for (i = 1; i < prom_argc; i++) {
+		strcpy(c, prom_argv[i]);
+		c += strlen(prom_argv[i]);
+		if (i < prom_argc-1)
+			*c++ = ' ';
+	}
+	*c = 0;
+}
+
+void __init prom_init(void)
+{
+	prom_argc = fw_arg0;
+	prom_argv = (char **)fw_arg1;
+	prom_envp = (char **)fw_arg2;
+
+	prom_init_cmdline();
+
+	memsize = env_or_default("memsize", DEFAULT_MEMSIZE);
+	highmemsize = env_or_default("highmemsize", 0x0);
+}
+
+void __init prom_free_prom_memory(void)
+{
+}
+
+#define PORT(offset)	(u8 *)(KSEG1ADDR(LS1X_UART0_BASE + offset))
+
+void __init prom_putchar(char c)
+{
+	int timeout;
+
+	timeout = 1024;
+
+	while (((readb(PORT(UART_LSR)) & UART_LSR_THRE) == 0)
+			&& (timeout-- > 0))
+		;
+
+	writeb(c, PORT(UART_TX));
+}
diff --git a/arch/mips/loongson1/common/reset.c b/arch/mips/loongson1/common/reset.c
new file mode 100644
index 000000000000..fb979a784eca
--- /dev/null
+++ b/arch/mips/loongson1/common/reset.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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/io.h>
+#include <linux/pm.h>
+#include <asm/reboot.h>
+
+#include <loongson1.h>
+
+static void ls1x_restart(char *command)
+{
+	__raw_writel(0x1, LS1X_WDT_EN);
+	__raw_writel(0x5000000, LS1X_WDT_TIMER);
+	__raw_writel(0x1, LS1X_WDT_SET);
+}
+
+static void ls1x_halt(void)
+{
+	while (1) {
+		if (cpu_wait)
+			cpu_wait();
+	}
+}
+
+static void ls1x_power_off(void)
+{
+	ls1x_halt();
+}
+
+static int __init ls1x_reboot_setup(void)
+{
+	_machine_restart = ls1x_restart;
+	_machine_halt = ls1x_halt;
+	pm_power_off = ls1x_power_off;
+
+	return 0;
+}
+
+arch_initcall(ls1x_reboot_setup);
diff --git a/arch/mips/loongson1/common/setup.c b/arch/mips/loongson1/common/setup.c
new file mode 100644
index 000000000000..62128cc27e68
--- /dev/null
+++ b/arch/mips/loongson1/common/setup.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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 <asm/bootinfo.h>
+
+#include <prom.h>
+
+void __init plat_mem_setup(void)
+{
+	add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);
+}
+
+const char *get_system_type(void)
+{
+	unsigned int processor_id = (&current_cpu_data)->processor_id;
+
+	switch (processor_id & PRID_REV_MASK) {
+	case PRID_REV_LOONGSON1B:
+		return "LOONGSON LS1B";
+	default:
+		return "LOONGSON (unknown)";
+	}
+}
diff --git a/arch/mips/loongson1/ls1b/Makefile b/arch/mips/loongson1/ls1b/Makefile
new file mode 100644
index 000000000000..891eac482b82
--- /dev/null
+++ b/arch/mips/loongson1/ls1b/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for loongson1B based machines.
+#
+
+obj-y += board.o
diff --git a/arch/mips/loongson1/ls1b/board.c b/arch/mips/loongson1/ls1b/board.c
new file mode 100644
index 000000000000..295b1be893e3
--- /dev/null
+++ b/arch/mips/loongson1/ls1b/board.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2011 Zhang, Keguang <keguang.zhang@gmail.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 <platform.h>
+
+#include <linux/serial_8250.h>
+#include <loongson1.h>
+
+static struct platform_device *ls1b_platform_devices[] __initdata = {
+	&ls1x_uart_device,
+	&ls1x_eth0_device,
+	&ls1x_ehci_device,
+	&ls1x_rtc_device,
+};
+
+static int __init ls1b_platform_init(void)
+{
+	int err;
+
+	ls1x_serial_setup();
+
+	err = platform_add_devices(ls1b_platform_devices,
+				   ARRAY_SIZE(ls1b_platform_devices));
+	return err;
+}
+
+arch_initcall(ls1b_platform_init);