18 files changed, 1585 insertions, 0 deletions

diff --git a/arch/arm/plat-spear/Kconfig b/arch/arm/plat-spear/Kconfig
new file mode 100644
index 00000000000..1bb3dbce881
--- /dev/null
+++ b/arch/arm/plat-spear/Kconfig
@@ -0,0 +1,31 @@
+#
+# SPEAr Platform configuration file
+#
+
+if PLAT_SPEAR
+
+choice
+	prompt "ST SPEAr Family"
+	default ARCH_SPEAR3XX
+
+config ARCH_SPEAR3XX
+	bool "SPEAr3XX"
+	select ARM_VIC
+	select CPU_ARM926T
+	help
+	  Supports for ARM's SPEAR3XX family
+
+config ARCH_SPEAR6XX
+	bool "SPEAr6XX"
+	select ARM_VIC
+	select CPU_ARM926T
+	help
+	  Supports for ARM's SPEAR6XX family
+
+endchoice
+
+# Adding SPEAr machine specific configuration files
+source "arch/arm/mach-spear3xx/Kconfig"
+source "arch/arm/mach-spear6xx/Kconfig"
+
+endif
diff --git a/arch/arm/plat-spear/Makefile b/arch/arm/plat-spear/Makefile
new file mode 100644
index 00000000000..eb89540aeda
--- /dev/null
+++ b/arch/arm/plat-spear/Makefile
@@ -0,0 +1,8 @@
+#
+# SPEAr Platform specific Makefile
+#
+
+# Common support
+obj-y	:= clock.o padmux.o time.o
+
+obj-$(CONFIG_ARCH_SPEAR3XX)	+= shirq.o
diff --git a/arch/arm/plat-spear/clock.c b/arch/arm/plat-spear/clock.c
new file mode 100644
index 00000000000..ee4f90e534d
--- /dev/null
+++ b/arch/arm/plat-spear/clock.c
@@ -0,0 +1,435 @@
+/*
+ * arch/arm/plat-spear/clock.c
+ *
+ * Clock framework for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <mach/misc_regs.h>
+#include <plat/clock.h>
+
+static DEFINE_SPINLOCK(clocks_lock);
+static LIST_HEAD(root_clks);
+
+static void propagate_rate(struct list_head *);
+
+static int generic_clk_enable(struct clk *clk)
+{
+	unsigned int val;
+
+	if (!clk->en_reg)
+		return -EFAULT;
+
+	val = readl(clk->en_reg);
+	if (unlikely(clk->flags & RESET_TO_ENABLE))
+		val &= ~(1 << clk->en_reg_bit);
+	else
+		val |= 1 << clk->en_reg_bit;
+
+	writel(val, clk->en_reg);
+
+	return 0;
+}
+
+static void generic_clk_disable(struct clk *clk)
+{
+	unsigned int val;
+
+	if (!clk->en_reg)
+		return;
+
+	val = readl(clk->en_reg);
+	if (unlikely(clk->flags & RESET_TO_ENABLE))
+		val |= 1 << clk->en_reg_bit;
+	else
+		val &= ~(1 << clk->en_reg_bit);
+
+	writel(val, clk->en_reg);
+}
+
+/* generic clk ops */
+static struct clkops generic_clkops = {
+	.enable = generic_clk_enable,
+	.disable = generic_clk_disable,
+};
+
+/*
+ * clk_enable - inform the system when the clock source should be running.
+ * @clk: clock source
+ *
+ * If the clock can not be enabled/disabled, this should return success.
+ *
+ * Returns success (0) or negative errno.
+ */
+int clk_enable(struct clk *clk)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (!clk || IS_ERR(clk))
+		return -EFAULT;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	if (clk->usage_count == 0) {
+		if (clk->ops && clk->ops->enable)
+			ret = clk->ops->enable(clk);
+	}
+	clk->usage_count++;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_enable);
+
+/*
+ * clk_disable - inform the system when the clock source is no longer required.
+ * @clk: clock source
+ *
+ * Inform the system that a clock source is no longer required by
+ * a driver and may be shut down.
+ *
+ * Implementation detail: if the clock source is shared between
+ * multiple drivers, clk_enable() calls must be balanced by the
+ * same number of clk_disable() calls for the clock source to be
+ * disabled.
+ */
+void clk_disable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (!clk || IS_ERR(clk))
+		return;
+
+	WARN_ON(clk->usage_count == 0);
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	clk->usage_count--;
+	if (clk->usage_count == 0) {
+		if (clk->ops && clk->ops->disable)
+			clk->ops->disable(clk);
+	}
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+/**
+ * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
+ *		 This is only valid once the clock source has been enabled.
+ * @clk: clock source
+ */
+unsigned long clk_get_rate(struct clk *clk)
+{
+	unsigned long flags, rate;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	rate = clk->rate;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	return rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+/**
+ * clk_set_parent - set the parent clock source for this clock
+ * @clk: clock source
+ * @parent: parent clock source
+ *
+ * Returns success (0) or negative errno.
+ */
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	int i, found = 0, val = 0;
+	unsigned long flags;
+
+	if (!clk || IS_ERR(clk) || !parent || IS_ERR(parent))
+		return -EFAULT;
+	if (clk->usage_count)
+		return -EBUSY;
+	if (!clk->pclk_sel)
+		return -EPERM;
+	if (clk->pclk == parent)
+		return 0;
+
+	for (i = 0; i < clk->pclk_sel->pclk_count; i++) {
+		if (clk->pclk_sel->pclk_info[i].pclk == parent) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	/* reflect parent change in hardware */
+	val = readl(clk->pclk_sel->pclk_sel_reg);
+	val &= ~(clk->pclk_sel->pclk_sel_mask << clk->pclk_sel_shift);
+	val |= clk->pclk_sel->pclk_info[i].pclk_mask << clk->pclk_sel_shift;
+	writel(val, clk->pclk_sel->pclk_sel_reg);
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	/* reflect parent change in software */
+	clk->recalc(clk);
+	propagate_rate(&clk->children);
+	return 0;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+/* registers clock in platform clock framework */
+void clk_register(struct clk_lookup *cl)
+{
+	struct clk *clk = cl->clk;
+	unsigned long flags;
+
+	if (!clk || IS_ERR(clk))
+		return;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+
+	INIT_LIST_HEAD(&clk->children);
+	if (clk->flags & ALWAYS_ENABLED)
+		clk->ops = NULL;
+	else if (!clk->ops)
+		clk->ops = &generic_clkops;
+
+	/* root clock don't have any parents */
+	if (!clk->pclk && !clk->pclk_sel) {
+		list_add(&clk->sibling, &root_clks);
+		/* add clocks with only one parent to parent's children list */
+	} else if (clk->pclk && !clk->pclk_sel) {
+		list_add(&clk->sibling, &clk->pclk->children);
+	} else {
+		/* add clocks with > 1 parent to 1st parent's children list */
+		list_add(&clk->sibling,
+			 &clk->pclk_sel->pclk_info[0].pclk->children);
+	}
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	/* add clock to arm clockdev framework */
+	clkdev_add(cl);
+}
+
+/**
+ * propagate_rate - recalculate and propagate all clocks in list head
+ *
+ * Recalculates all root clocks in list head, which if the clock's .recalc is
+ * set correctly, should also propagate their rates.
+ */
+static void propagate_rate(struct list_head *lhead)
+{
+	struct clk *clkp, *_temp;
+
+	list_for_each_entry_safe(clkp, _temp, lhead, sibling) {
+		if (clkp->recalc)
+			clkp->recalc(clkp);
+		propagate_rate(&clkp->children);
+	}
+}
+
+/* returns current programmed clocks clock info structure */
+static struct pclk_info *pclk_info_get(struct clk *clk)
+{
+	unsigned int mask, i;
+	unsigned long flags;
+	struct pclk_info *info = NULL;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	mask = (readl(clk->pclk_sel->pclk_sel_reg) >> clk->pclk_sel_shift)
+			& clk->pclk_sel->pclk_sel_mask;
+
+	for (i = 0; i < clk->pclk_sel->pclk_count; i++) {
+		if (clk->pclk_sel->pclk_info[i].pclk_mask == mask)
+			info = &clk->pclk_sel->pclk_info[i];
+	}
+	spin_unlock_irqrestore(&clocks_lock, flags);
+
+	return info;
+}
+
+/*
+ * Set pclk as cclk's parent and add clock sibling node to current parents
+ * children list
+ */
+static void change_parent(struct clk *cclk, struct clk *pclk)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	list_del(&cclk->sibling);
+	list_add(&cclk->sibling, &pclk->children);
+
+	cclk->pclk = pclk;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/*
+ * calculates current programmed rate of pll1
+ *
+ * In normal mode
+ * rate = (2 * M[15:8] * Fin)/(N * 2^P)
+ *
+ * In Dithered mode
+ * rate = (2 * M[15:0] * Fin)/(256 * N * 2^P)
+ */
+void pll1_clk_recalc(struct clk *clk)
+{
+	struct pll_clk_config *config = clk->private_data;
+	unsigned int num = 2, den = 0, val, mode = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	mode = (readl(config->mode_reg) >> PLL_MODE_SHIFT) &
+		PLL_MODE_MASK;
+
+	val = readl(config->cfg_reg);
+	/* calculate denominator */
+	den = (val >> PLL_DIV_P_SHIFT) & PLL_DIV_P_MASK;
+	den = 1 << den;
+	den *= (val >> PLL_DIV_N_SHIFT) & PLL_DIV_N_MASK;
+
+	/* calculate numerator & denominator */
+	if (!mode) {
+		/* Normal mode */
+		num *= (val >> PLL_NORM_FDBK_M_SHIFT) & PLL_NORM_FDBK_M_MASK;
+	} else {
+		/* Dithered mode */
+		num *= (val >> PLL_DITH_FDBK_M_SHIFT) & PLL_DITH_FDBK_M_MASK;
+		den *= 256;
+	}
+
+	clk->rate = (((clk->pclk->rate/10000) * num) / den) * 10000;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/* calculates current programmed rate of ahb or apb bus */
+void bus_clk_recalc(struct clk *clk)
+{
+	struct bus_clk_config *config = clk->private_data;
+	unsigned int div;
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	div = ((readl(config->reg) >> config->shift) & config->mask) + 1;
+	clk->rate = (unsigned long)clk->pclk->rate / div;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/*
+ * calculates current programmed rate of auxiliary synthesizers
+ * used by: UART, FIRDA
+ *
+ * Fout from synthesizer can be given from two equations:
+ * Fout1 = (Fin * X/Y)/2
+ * Fout2 = Fin * X/Y
+ *
+ * Selection of eqn 1 or 2 is programmed in register
+ */
+void aux_clk_recalc(struct clk *clk)
+{
+	struct aux_clk_config *config = clk->private_data;
+	struct pclk_info *pclk_info = NULL;
+	unsigned int num = 1, den = 1, val, eqn;
+	unsigned long flags;
+
+	/* get current programmed parent */
+	pclk_info = pclk_info_get(clk);
+	if (!pclk_info) {
+		spin_lock_irqsave(&clocks_lock, flags);
+		clk->pclk = NULL;
+		clk->rate = 0;
+		spin_unlock_irqrestore(&clocks_lock, flags);
+		return;
+	}
+
+	change_parent(clk, pclk_info->pclk);
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	if (pclk_info->scalable) {
+		val = readl(config->synth_reg);
+
+		eqn = (val >> AUX_EQ_SEL_SHIFT) & AUX_EQ_SEL_MASK;
+		if (eqn == AUX_EQ1_SEL)
+			den *= 2;
+
+		/* calculate numerator */
+		num = (val >> AUX_XSCALE_SHIFT) & AUX_XSCALE_MASK;
+
+		/* calculate denominator */
+		den *= (val >> AUX_YSCALE_SHIFT) & AUX_YSCALE_MASK;
+		val = (((clk->pclk->rate/10000) * num) / den) * 10000;
+	} else
+		val = clk->pclk->rate;
+
+	clk->rate = val;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/*
+ * calculates current programmed rate of gpt synthesizers
+ * Fout from synthesizer can be given from below equations:
+ * Fout= Fin/((2 ^ (N+1)) * (M+1))
+ */
+void gpt_clk_recalc(struct clk *clk)
+{
+	struct aux_clk_config *config = clk->private_data;
+	struct pclk_info *pclk_info = NULL;
+	unsigned int div = 1, val;
+	unsigned long flags;
+
+	pclk_info = pclk_info_get(clk);
+	if (!pclk_info) {
+		spin_lock_irqsave(&clocks_lock, flags);
+		clk->pclk = NULL;
+		clk->rate = 0;
+		spin_unlock_irqrestore(&clocks_lock, flags);
+		return;
+	}
+
+	change_parent(clk, pclk_info->pclk);
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	if (pclk_info->scalable) {
+		val = readl(config->synth_reg);
+		div += (val >> GPT_MSCALE_SHIFT) & GPT_MSCALE_MASK;
+		div *= 1 << (((val >> GPT_NSCALE_SHIFT) & GPT_NSCALE_MASK) + 1);
+	}
+
+	clk->rate = (unsigned long)clk->pclk->rate / div;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/*
+ * Used for clocks that always have same value as the parent clock divided by a
+ * fixed divisor
+ */
+void follow_parent(struct clk *clk)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocks_lock, flags);
+	clk->rate = clk->pclk->rate;
+	spin_unlock_irqrestore(&clocks_lock, flags);
+}
+
+/**
+ * recalc_root_clocks - recalculate and propagate all root clocks
+ *
+ * Recalculates all root clocks (clocks with no parent), which if the
+ * clock's .recalc is set correctly, should also propagate their rates.
+ */
+void recalc_root_clocks(void)
+{
+	propagate_rate(&root_clks);
+}
diff --git a/arch/arm/plat-spear/include/plat/clkdev.h b/arch/arm/plat-spear/include/plat/clkdev.h
new file mode 100644
index 00000000000..a2d0112fcaf
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/clkdev.h
@@ -0,0 +1,20 @@
+/*
+ * arch/arm/plat-spear/include/plat/clkdev.h
+ *
+ * Clock Dev framework definitions for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_CLKDEV_H
+#define __PLAT_CLKDEV_H
+
+#define __clk_get(clk) ({ 1; })
+#define __clk_put(clk) do { } while (0)
+
+#endif /* __PLAT_CLKDEV_H */
diff --git a/arch/arm/plat-spear/include/plat/clock.h b/arch/arm/plat-spear/include/plat/clock.h
new file mode 100644
index 00000000000..298bafc0a52
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/clock.h
@@ -0,0 +1,126 @@
+/*
+ * arch/arm/plat-spear/include/plat/clock.h
+ *
+ * Clock framework definitions for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_CLOCK_H
+#define __PLAT_CLOCK_H
+
+#include <linux/list.h>
+#include <asm/clkdev.h>
+#include <linux/types.h>
+
+/* clk structure flags */
+#define	ALWAYS_ENABLED		(1 << 0) /* clock always enabled */
+#define	RESET_TO_ENABLE		(1 << 1) /* reset register bit to enable clk */
+
+/**
+ * struct clkops - clock operations
+ * @enable: pointer to clock enable function
+ * @disable: pointer to clock disable function
+ */
+struct clkops {
+	int (*enable) (struct clk *);
+	void (*disable) (struct clk *);
+};
+
+/**
+ * struct pclk_info - parents info
+ * @pclk: pointer to parent clk
+ * @pclk_mask: value to be written for selecting this parent
+ * @scalable: Is parent scalable (1 - YES, 0 - NO)
+ */
+struct pclk_info {
+	struct clk *pclk;
+	u8 pclk_mask;
+	u8 scalable;
+};
+
+/**
+ * struct pclk_sel - parents selection configuration
+ * @pclk_info: pointer to array of parent clock info
+ * @pclk_count: number of parents
+ * @pclk_sel_reg: register for selecting a parent
+ * @pclk_sel_mask: mask for selecting parent (can be used to clear bits also)
+ */
+struct pclk_sel {
+	struct pclk_info *pclk_info;
+	u8 pclk_count;
+	unsigned int *pclk_sel_reg;
+	unsigned int pclk_sel_mask;
+};
+
+/**
+ * struct clk - clock structure
+ * @usage_count: num of users who enabled this clock
+ * @flags: flags for clock properties
+ * @rate: programmed clock rate in Hz
+ * @en_reg: clk enable/disable reg
+ * @en_reg_bit: clk enable/disable bit
+ * @ops: clk enable/disable ops - generic_clkops selected if NULL
+ * @recalc: pointer to clock rate recalculate function
+ * @pclk: current parent clk
+ * @pclk_sel: pointer to parent selection structure
+ * @pclk_sel_shift: register shift for selecting parent of this clock
+ * @children: list for childrens or this clock
+ * @sibling: node for list of clocks having same parents
+ * @private_data: clock specific private data
+ */
+struct clk {
+	unsigned int usage_count;
+	unsigned int flags;
+	unsigned long rate;
+	unsigned int *en_reg;
+	u8 en_reg_bit;
+	const struct clkops *ops;
+	void (*recalc) (struct clk *);
+
+	struct clk *pclk;
+	struct pclk_sel *pclk_sel;
+	unsigned int pclk_sel_shift;
+
+	struct list_head children;
+	struct list_head sibling;
+	void *private_data;
+};
+
+/* pll configuration structure */
+struct pll_clk_config {
+	unsigned int *mode_reg;
+	unsigned int *cfg_reg;
+};
+
+/* ahb and apb bus configuration structure */
+struct bus_clk_config {
+	unsigned int *reg;
+	unsigned int mask;
+	unsigned int shift;
+};
+
+/*
+ * Aux clk configuration structure: applicable to GPT, UART and FIRDA
+ */
+struct aux_clk_config {
+	unsigned int *synth_reg;
+};
+
+/* platform specific clock functions */
+void clk_register(struct clk_lookup *cl);
+void recalc_root_clocks(void);
+
+/* clock recalc functions */
+void follow_parent(struct clk *clk);
+void pll1_clk_recalc(struct clk *clk);
+void bus_clk_recalc(struct clk *clk);
+void gpt_clk_recalc(struct clk *clk);
+void aux_clk_recalc(struct clk *clk);
+
+#endif /* __PLAT_CLOCK_H */
diff --git a/arch/arm/plat-spear/include/plat/debug-macro.S b/arch/arm/plat-spear/include/plat/debug-macro.S
new file mode 100644
index 00000000000..37fa593884e
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/debug-macro.S
@@ -0,0 +1,38 @@
+/*
+ * arch/arm/plat-spear/include/plat/debug-macro.S
+ *
+ * Debugging macro include header for spear platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/amba/serial.h>
+#include <mach/spear.h>
+
+		.macro	addruart, rx
+		mrc	p15, 0, \rx, c1, c0
+		tst	\rx, #1					@ MMU enabled?
+		moveq	\rx, #SPEAR_DBG_UART_BASE		@ Physical base
+		movne	\rx, #VA_SPEAR_DBG_UART_BASE		@ Virtual base
+		.endm
+
+		.macro	senduart, rd, rx
+		strb	\rd, [\rx, #UART01x_DR]			@ ASC_TX_BUFFER
+		.endm
+
+		.macro	waituart, rd, rx
+1001:		ldr	\rd, [\rx, #UART01x_FR]			@ FLAG REGISTER
+		tst	\rd, #UART01x_FR_TXFF			@ TX_FULL
+		bne	1001b
+		.endm
+
+		.macro	busyuart, rd, rx
+1002:		ldr	\rd, [\rx, #UART01x_FR]			@ FLAG REGISTER
+		tst	\rd, #UART011_FR_TXFE			@ TX_EMPTY
+		beq	1002b
+		.endm
diff --git a/arch/arm/plat-spear/include/plat/gpio.h b/arch/arm/plat-spear/include/plat/gpio.h
new file mode 100644
index 00000000000..b857c91257d
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/gpio.h
@@ -0,0 +1,24 @@
+/*
+ * arch/arm/plat-spear/include/plat/gpio.h
+ *
+ * GPIO macros for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_GPIO_H
+#define __PLAT_GPIO_H
+
+#include <asm-generic/gpio.h>
+
+#define gpio_get_value	__gpio_get_value
+#define gpio_set_value	__gpio_set_value
+#define gpio_cansleep	__gpio_cansleep
+#define gpio_to_irq	__gpio_to_irq
+
+#endif /* __PLAT_GPIO_H */
diff --git a/arch/arm/plat-spear/include/plat/io.h b/arch/arm/plat-spear/include/plat/io.h
new file mode 100644
index 00000000000..4d4ba822b3e
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/io.h
@@ -0,0 +1,22 @@
+/*
+ * arch/arm/plat-spear/include/plat/io.h
+ *
+ * IO definitions for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_IO_H
+#define __PLAT_IO_H
+
+#define IO_SPACE_LIMIT		0xFFFFFFFF
+
+#define __io(a)			__typesafe_io(a)
+#define __mem_pci(a)		(a)
+
+#endif /* __PLAT_IO_H */
diff --git a/arch/arm/plat-spear/include/plat/memory.h b/arch/arm/plat-spear/include/plat/memory.h
new file mode 100644
index 00000000000..27a4aba7734
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/memory.h
@@ -0,0 +1,20 @@
+/*
+ * arch/arm/plat-spear/include/plat/memory.h
+ *
+ * Memory map for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_MEMORY_H
+#define __PLAT_MEMORY_H
+
+/* Physical DRAM offset */
+#define PHYS_OFFSET		UL(0x00000000)
+
+#endif /* __PLAT_MEMORY_H */
diff --git a/arch/arm/plat-spear/include/plat/padmux.h b/arch/arm/plat-spear/include/plat/padmux.h
new file mode 100644
index 00000000000..877f3adcf61
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/padmux.h
@@ -0,0 +1,92 @@
+/*
+ * arch/arm/plat-spear/include/plat/padmux.h
+ *
+ * SPEAr platform specific gpio pads muxing file
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_PADMUX_H
+#define __PLAT_PADMUX_H
+
+#include <linux/types.h>
+
+/*
+ * struct pmx_reg: configuration structure for mode reg and mux reg
+ *
+ * offset: offset of mode reg
+ * mask: mask of mode reg
+ */
+struct pmx_reg {
+	u32 offset;
+	u32 mask;
+};
+
+/*
+ * struct pmx_dev_mode: configuration structure every group of modes of a device
+ *
+ * ids: all modes for this configuration
+ * mask: mask for supported mode
+ */
+struct pmx_dev_mode {
+	u32 ids;
+	u32 mask;
+};
+
+/*
+ * struct pmx_mode: mode definition structure
+ *
+ * name: mode name
+ * mask: mode mask
+ */
+struct pmx_mode {
+	char *name;
+	u32 id;
+	u32 mask;
+};
+
+/*
+ * struct pmx_dev: device definition structure
+ *
+ * name: device name
+ * modes: device configuration array for different modes supported
+ * mode_count: size of modes array
+ * is_active: is peripheral active/enabled
+ * enb_on_reset: if 1, mask bits to be cleared in reg otherwise to be set in reg
+ */
+struct pmx_dev {
+	char *name;
+	struct pmx_dev_mode *modes;
+	u8 mode_count;
+	bool is_active;
+	bool enb_on_reset;
+};
+
+/*
+ * struct pmx_driver: driver definition structure
+ *
+ * mode: mode to be set
+ * devs: array of pointer to pmx devices
+ * devs_count: ARRAY_SIZE of devs
+ * base: base address of soc config registers
+ * mode_reg: structure of mode config register
+ * mux_reg: structure of device mux config register
+ */
+struct pmx_driver {
+	struct pmx_mode *mode;
+	struct pmx_dev **devs;
+	u8 devs_count;
+	u32 *base;
+	struct pmx_reg mode_reg;
+	struct pmx_reg mux_reg;
+};
+
+/* pmx functions */
+int pmx_register(struct pmx_driver *driver);
+
+#endif /* __PLAT_PADMUX_H */
diff --git a/arch/arm/plat-spear/include/plat/shirq.h b/arch/arm/plat-spear/include/plat/shirq.h
new file mode 100644
index 00000000000..03ed8b585dc
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/shirq.h
@@ -0,0 +1,73 @@
+/*
+ * arch/arm/plat-spear/include/plat/shirq.h
+ *
+ * SPEAr platform shared irq layer header file
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_SHIRQ_H
+#define __PLAT_SHIRQ_H
+
+#include <linux/irq.h>
+#include <linux/types.h>
+
+/*
+ * struct shirq_dev_config: shared irq device configuration
+ *
+ * virq: virtual irq number of device
+ * enb_mask: enable mask of device
+ * status_mask: status mask of device
+ * clear_mask: clear mask of device
+ */
+struct shirq_dev_config {
+	u32 virq;
+	u32 enb_mask;
+	u32 status_mask;
+	u32 clear_mask;
+};
+
+/*
+ * struct shirq_regs: shared irq register configuration
+ *
+ * base: base address of shared irq register
+ * enb_reg: enable register offset
+ * reset_to_enb: val 1 indicates, we need to clear bit for enabling interrupt
+ * status_reg: status register offset
+ * status_reg_mask: status register valid mask
+ * clear_reg: clear register offset
+ * reset_to_clear: val 1 indicates, we need to clear bit for clearing interrupt
+ */
+struct shirq_regs {
+	void __iomem *base;
+	u32 enb_reg;
+	u32 reset_to_enb;
+	u32 status_reg;
+	u32 status_reg_mask;
+	u32 clear_reg;
+	u32 reset_to_clear;
+};
+
+/*
+ * struct spear_shirq: shared irq structure
+ *
+ * irq: hardware irq number
+ * dev_config: array of device config structures which are using "irq" line
+ * dev_count: size of dev_config array
+ * regs: register configuration for shared irq block
+ */
+struct spear_shirq {
+	u32 irq;
+	struct shirq_dev_config *dev_config;
+	u32 dev_count;
+	struct shirq_regs regs;
+};
+
+int spear_shirq_register(struct spear_shirq *shirq);
+
+#endif /* __PLAT_SHIRQ_H */
diff --git a/arch/arm/plat-spear/include/plat/system.h b/arch/arm/plat-spear/include/plat/system.h
new file mode 100644
index 00000000000..55a4e405d57
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/system.h
@@ -0,0 +1,41 @@
+/*
+ * arch/arm/plat-spear/include/plat/system.h
+ *
+ * SPEAr platform specific architecture functions
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_SYSTEM_H
+#define __PLAT_SYSTEM_H
+
+#include <asm/hardware/sp810.h>
+#include <linux/io.h>
+#include <mach/spear.h>
+
+static inline void arch_idle(void)
+{
+	/*
+	 * This should do all the clock switching
+	 * and wait for interrupt tricks
+	 */
+	cpu_do_idle();
+}
+
+static inline void arch_reset(char mode, const char *cmd)
+{
+	if (mode == 's') {
+		/* software reset, Jump into ROM at address 0 */
+		cpu_reset(0);
+	} else {
+		/* hardware reset, Use on-chip reset capability */
+		sysctl_soft_reset((void __iomem *)VA_SPEAR_SYS_CTRL_BASE);
+	}
+}
+
+#endif /* __PLAT_SYSTEM_H */
diff --git a/arch/arm/plat-spear/include/plat/timex.h b/arch/arm/plat-spear/include/plat/timex.h
new file mode 100644
index 00000000000..914d09dd50f
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/timex.h
@@ -0,0 +1,19 @@
+/*
+ * arch/arm/plat-spear/include/plat/timex.h
+ *
+ * SPEAr platform specific timex definitions
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_TIMEX_H
+#define __PLAT_TIMEX_H
+
+#define CLOCK_TICK_RATE			48000000
+
+#endif /* __PLAT_TIMEX_H */
diff --git a/arch/arm/plat-spear/include/plat/uncompress.h b/arch/arm/plat-spear/include/plat/uncompress.h
new file mode 100644
index 00000000000..99ba6789cc9
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/uncompress.h
@@ -0,0 +1,43 @@
+/*
+ * arch/arm/plat-spear/include/plat/uncompress.h
+ *
+ * Serial port stubs for kernel decompress status messages
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/io.h>
+#include <linux/amba/serial.h>
+#include <mach/spear.h>
+
+#ifndef __PLAT_UNCOMPRESS_H
+#define __PLAT_UNCOMPRESS_H
+/*
+ * This does not append a newline
+ */
+static inline void putc(int c)
+{
+	void __iomem *base = (void __iomem *)SPEAR_DBG_UART_BASE;
+
+	while (readl(base + UART01x_FR) & UART01x_FR_TXFF)
+		barrier();
+
+	writel(c, base + UART01x_DR);
+}
+
+static inline void flush(void)
+{
+}
+
+/*
+ * nothing to do
+ */
+#define arch_decomp_setup()
+#define arch_decomp_wdog()
+
+#endif /* __PLAT_UNCOMPRESS_H */
diff --git a/arch/arm/plat-spear/include/plat/vmalloc.h b/arch/arm/plat-spear/include/plat/vmalloc.h
new file mode 100644
index 00000000000..09e9372aea2
--- /dev/null
+++ b/arch/arm/plat-spear/include/plat/vmalloc.h
@@ -0,0 +1,19 @@
+/*
+ * arch/arm/plat-spear/include/plat/vmalloc.h
+ *
+ * Defining Vmalloc area for SPEAr platform
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __PLAT_VMALLOC_H
+#define __PLAT_VMALLOC_H
+
+#define VMALLOC_END		0xF0000000
+
+#endif /* __PLAT_VMALLOC_H */
diff --git a/arch/arm/plat-spear/padmux.c b/arch/arm/plat-spear/padmux.c
new file mode 100644
index 00000000000..d2aab3adcde
--- /dev/null
+++ b/arch/arm/plat-spear/padmux.c
@@ -0,0 +1,164 @@
+/*
+ * arch/arm/plat-spear/include/plat/padmux.c
+ *
+ * SPEAr platform specific gpio pads muxing source file
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <plat/padmux.h>
+
+/*
+ * struct pmx: pmx definition structure
+ *
+ * base: base address of configuration registers
+ * mode_reg: mode configurations
+ * mux_reg: muxing configurations
+ * active_mode: pointer to current active mode
+ */
+struct pmx {
+	u32 base;
+	struct pmx_reg mode_reg;
+	struct pmx_reg mux_reg;
+	struct pmx_mode *active_mode;
+};
+
+static struct pmx *pmx;
+
+/**
+ * pmx_mode_set - Enables an multiplexing mode
+ * @mode - pointer to pmx mode
+ *
+ * It will set mode of operation in hardware.
+ * Returns -ve on Err otherwise 0
+ */
+static int pmx_mode_set(struct pmx_mode *mode)
+{
+	u32 val;
+
+	if (!mode->name)
+		return -EFAULT;
+
+	pmx->active_mode = mode;
+
+	val = readl(pmx->base + pmx->mode_reg.offset);
+	val &= ~pmx->mode_reg.mask;
+	val |= mode->mask & pmx->mode_reg.mask;
+	writel(val, pmx->base + pmx->mode_reg.offset);
+
+	return 0;
+}
+
+/**
+ * pmx_devs_enable - Enables list of devices
+ * @devs - pointer to pmx device array
+ * @count - number of devices to enable
+ *
+ * It will enable pads for all required peripherals once and only once.
+ * If peripheral is not supported by current mode then request is rejected.
+ * Conflicts between peripherals are not handled and peripherals will be
+ * enabled in the order they are present in pmx_dev array.
+ * In case of conflicts last peripheral enalbed will be present.
+ * Returns -ve on Err otherwise 0
+ */
+static int pmx_devs_enable(struct pmx_dev **devs, u8 count)
+{
+	u32 val, i, mask;
+
+	if (!count)
+		return -EINVAL;
+
+	val = readl(pmx->base + pmx->mux_reg.offset);
+	for (i = 0; i < count; i++) {
+		u8 j = 0;
+
+		if (!devs[i]->name || !devs[i]->modes) {
+			printk(KERN_ERR "padmux: dev name or modes is null\n");
+			continue;
+		}
+		/* check if peripheral exists in active mode */
+		if (pmx->active_mode) {
+			bool found = false;
+			for (j = 0; j < devs[i]->mode_count; j++) {
+				if (devs[i]->modes[j].ids &
+						pmx->active_mode->id) {
+					found = true;
+					break;
+				}
+			}
+			if (found == false) {
+				printk(KERN_ERR "%s device not available in %s"\
+						"mode\n", devs[i]->name,
+						pmx->active_mode->name);
+				continue;
+			}
+		}
+
+		/* enable peripheral */
+		mask = devs[i]->modes[j].mask & pmx->mux_reg.mask;
+		if (devs[i]->enb_on_reset)
+			val &= ~mask;
+		else
+			val |= mask;
+
+		devs[i]->is_active = true;
+	}
+	writel(val, pmx->base + pmx->mux_reg.offset);
+	kfree(pmx);
+
+	/* this will ensure that multiplexing can't be changed now */
+	pmx = (struct pmx *)-1;
+
+	return 0;
+}
+
+/**
+ * pmx_register - registers a platform requesting pad mux feature
+ * @driver - pointer to driver structure containing driver specific parameters
+ *
+ * Also this must be called only once. This will allocate memory for pmx
+ * structure, will call pmx_mode_set, will call pmx_devs_enable.
+ * Returns -ve on Err otherwise 0
+ */
+int pmx_register(struct pmx_driver *driver)
+{
+	int ret = 0;
+
+	if (pmx)
+		return -EPERM;
+	if (!driver->base || !driver->devs)
+		return -EFAULT;
+
+	pmx = kzalloc(sizeof(*pmx), GFP_KERNEL);
+	if (!pmx)
+		return -ENOMEM;
+
+	pmx->base = (u32)driver->base;
+	pmx->mode_reg.offset = driver->mode_reg.offset;
+	pmx->mode_reg.mask = driver->mode_reg.mask;
+	pmx->mux_reg.offset = driver->mux_reg.offset;
+	pmx->mux_reg.mask = driver->mux_reg.mask;
+
+	/* choose mode to enable */
+	if (driver->mode) {
+		ret = pmx_mode_set(driver->mode);
+		if (ret)
+			goto pmx_fail;
+	}
+	ret = pmx_devs_enable(driver->devs, driver->devs_count);
+	if (ret)
+		goto pmx_fail;
+
+	return 0;
+
+pmx_fail:
+	return ret;
+}
diff --git a/arch/arm/plat-spear/shirq.c b/arch/arm/plat-spear/shirq.c
new file mode 100644
index 00000000000..2172d6946ae
--- /dev/null
+++ b/arch/arm/plat-spear/shirq.c
@@ -0,0 +1,118 @@
+/*
+ * arch/arm/plat-spear/shirq.c
+ *
+ * SPEAr platform shared irq layer source file
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <plat/shirq.h>
+
+struct spear_shirq *shirq;
+static DEFINE_SPINLOCK(lock);
+
+static void shirq_irq_mask(unsigned irq)
+{
+	struct spear_shirq *shirq = get_irq_chip_data(irq);
+	u32 val, id = irq - shirq->dev_config[0].virq;
+	unsigned long flags;
+
+	if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
+		return;
+
+	spin_lock_irqsave(&lock, flags);
+	val = readl(shirq->regs.base + shirq->regs.enb_reg);
+	if (shirq->regs.reset_to_enb)
+		val |= shirq->dev_config[id].enb_mask;
+	else
+		val &= ~(shirq->dev_config[id].enb_mask);
+	writel(val, shirq->regs.base + shirq->regs.enb_reg);
+	spin_unlock_irqrestore(&lock, flags);
+}
+
+static void shirq_irq_unmask(unsigned irq)
+{
+	struct spear_shirq *shirq = get_irq_chip_data(irq);
+	u32 val, id = irq - shirq->dev_config[0].virq;
+	unsigned long flags;
+
+	if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
+		return;
+
+	spin_lock_irqsave(&lock, flags);
+	val = readl(shirq->regs.base + shirq->regs.enb_reg);
+	if (shirq->regs.reset_to_enb)
+		val &= ~(shirq->dev_config[id].enb_mask);
+	else
+		val |= shirq->dev_config[id].enb_mask;
+	writel(val, shirq->regs.base + shirq->regs.enb_reg);
+	spin_unlock_irqrestore(&lock, flags);
+}
+
+static struct irq_chip shirq_chip = {
+	.name		= "spear_shirq",
+	.ack		= shirq_irq_mask,
+	.mask		= shirq_irq_mask,
+	.unmask		= shirq_irq_unmask,
+};
+
+static void shirq_handler(unsigned irq, struct irq_desc *desc)
+{
+	u32 i, val, mask;
+	struct spear_shirq *shirq = get_irq_data(irq);
+
+	desc->chip->ack(irq);
+	while ((val = readl(shirq->regs.base + shirq->regs.status_reg) &
+				shirq->regs.status_reg_mask)) {
+		for (i = 0; (i < shirq->dev_count) && val; i++) {
+			if (!(shirq->dev_config[i].status_mask & val))
+				continue;
+
+			generic_handle_irq(shirq->dev_config[i].virq);
+
+			/* clear interrupt */
+			val &= ~shirq->dev_config[i].status_mask;
+			if ((shirq->regs.clear_reg == -1) ||
+					shirq->dev_config[i].clear_mask == -1)
+				continue;
+			mask = readl(shirq->regs.base + shirq->regs.clear_reg);
+			if (shirq->regs.reset_to_clear)
+				mask &= ~shirq->dev_config[i].clear_mask;
+			else
+				mask |= shirq->dev_config[i].clear_mask;
+			writel(mask, shirq->regs.base + shirq->regs.clear_reg);
+		}
+	}
+	desc->chip->unmask(irq);
+}
+
+int spear_shirq_register(struct spear_shirq *shirq)
+{
+	int i;
+
+	if (!shirq || !shirq->dev_config || !shirq->regs.base)
+		return -EFAULT;
+
+	if (!shirq->dev_count)
+		return -EINVAL;
+
+	set_irq_chained_handler(shirq->irq, shirq_handler);
+	for (i = 0; i < shirq->dev_count; i++) {
+		set_irq_chip(shirq->dev_config[i].virq, &shirq_chip);
+		set_irq_handler(shirq->dev_config[i].virq, handle_simple_irq);
+		set_irq_flags(shirq->dev_config[i].virq, IRQF_VALID);
+		set_irq_chip_data(shirq->dev_config[i].virq, shirq);
+	}
+
+	set_irq_data(shirq->irq, shirq);
+	return 0;
+}
diff --git a/arch/arm/plat-spear/time.c b/arch/arm/plat-spear/time.c
new file mode 100644
index 00000000000..a1025d38f38
--- /dev/null
+++ b/arch/arm/plat-spear/time.c
@@ -0,0 +1,292 @@
+/*
+ * arch/arm/plat-spear/time.c
+ *
+ * Copyright (C) 2009 ST Microelectronics
+ * Shiraz Hashim<shiraz.hashim@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/irq.h>
+#include <asm/mach/time.h>
+#include <mach/irqs.h>
+#include <mach/hardware.h>
+#include <mach/spear.h>
+#include <mach/generic.h>
+
+/*
+ * We would use TIMER0 and TIMER1 as clockevent and clocksource.
+ * Timer0 and Timer1 both belong to same gpt block in cpu subbsystem. Further
+ * they share same functional clock. Any change in one's functional clock will
+ * also affect other timer.
+ */
+
+#define CLKEVT	0	/* gpt0, channel0 as clockevent */
+#define CLKSRC	1	/* gpt0, channel1 as clocksource */
+
+/* Register offsets, x is channel number */
+#define CR(x)		((x) * 0x80 + 0x80)
+#define IR(x)		((x) * 0x80 + 0x84)
+#define LOAD(x)		((x) * 0x80 + 0x88)
+#define COUNT(x)	((x) * 0x80 + 0x8C)
+
+/* Reg bit definitions */
+#define CTRL_INT_ENABLE		0x0100
+#define CTRL_ENABLE		0x0020
+#define CTRL_ONE_SHOT		0x0010
+
+#define CTRL_PRESCALER1		0x0
+#define CTRL_PRESCALER2		0x1
+#define CTRL_PRESCALER4		0x2
+#define CTRL_PRESCALER8		0x3
+#define CTRL_PRESCALER16	0x4
+#define CTRL_PRESCALER32	0x5
+#define CTRL_PRESCALER64	0x6
+#define CTRL_PRESCALER128	0x7
+#define CTRL_PRESCALER256	0x8
+
+#define INT_STATUS		0x1
+
+static __iomem void *gpt_base;
+static struct clk *gpt_clk;
+
+static void clockevent_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *clk_event_dev);
+static int clockevent_next_event(unsigned long evt,
+				 struct clock_event_device *clk_event_dev);
+
+/*
+ * Following clocksource_set_clock and clockevent_set_clock picked
+ * from arch/mips/kernel/time.c
+ */
+
+void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock)
+{
+	u64 temp;
+	u32 shift;
+
+	/* Find a shift value */
+	for (shift = 32; shift > 0; shift--) {
+		temp = (u64) NSEC_PER_SEC << shift;
+		do_div(temp, clock);
+		if ((temp >> 32) == 0)
+			break;
+	}
+	cs->shift = shift;
+	cs->mult = (u32) temp;
+}
+
+void __init clockevent_set_clock(struct clock_event_device *cd,
+	unsigned int clock)
+{
+	u64 temp;
+	u32 shift;
+
+	/* Find a shift value */
+	for (shift = 32; shift > 0; shift--) {
+		temp = (u64) clock << shift;
+		do_div(temp, NSEC_PER_SEC);
+		if ((temp >> 32) == 0)
+			break;
+	}
+	cd->shift = shift;
+	cd->mult = (u32) temp;
+}
+
+static cycle_t clocksource_read_cycles(struct clocksource *cs)
+{
+	return (cycle_t) readw(gpt_base + COUNT(CLKSRC));
+}
+
+static struct clocksource clksrc = {
+	.name = "tmr1",
+	.rating = 200,		/* its a pretty decent clock */
+	.read = clocksource_read_cycles,
+	.mask = 0xFFFF,		/* 16 bits */
+	.mult = 0,		/* to be computed */
+	.shift = 0,		/* to be computed */
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void spear_clocksource_init(void)
+{
+	u32 tick_rate;
+	u16 val;
+
+	/* program the prescaler (/256)*/
+	writew(CTRL_PRESCALER256, gpt_base + CR(CLKSRC));
+
+	/* find out actual clock driving Timer */
+	tick_rate = clk_get_rate(gpt_clk);
+	tick_rate >>= CTRL_PRESCALER256;
+
+	writew(0xFFFF, gpt_base + LOAD(CLKSRC));
+
+	val = readw(gpt_base + CR(CLKSRC));
+	val &= ~CTRL_ONE_SHOT;	/* autoreload mode */
+	val |= CTRL_ENABLE ;
+	writew(val, gpt_base + CR(CLKSRC));
+
+	clocksource_set_clock(&clksrc, tick_rate);
+
+	/* register the clocksource */
+	clocksource_register(&clksrc);
+}
+
+static struct clock_event_device clkevt = {
+	.name = "tmr0",
+	.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode = clockevent_set_mode,
+	.set_next_event = clockevent_next_event,
+	.shift = 0,	/* to be computed */
+};
+
+static void clockevent_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *clk_event_dev)
+{
+	u32 period;
+	u16 val;
+
+	/* stop the timer */
+	val = readw(gpt_base + CR(CLKEVT));
+	val &= ~CTRL_ENABLE;
+	writew(val, gpt_base + CR(CLKEVT));
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		period = clk_get_rate(gpt_clk) / HZ;
+		period >>= CTRL_PRESCALER16;
+		writew(period, gpt_base + LOAD(CLKEVT));
+
+		val = readw(gpt_base + CR(CLKEVT));
+		val &= ~CTRL_ONE_SHOT;
+		val |= CTRL_ENABLE | CTRL_INT_ENABLE;
+		writew(val, gpt_base + CR(CLKEVT));
+
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		val = readw(gpt_base + CR(CLKEVT));
+		val |= CTRL_ONE_SHOT;
+		writew(val, gpt_base + CR(CLKEVT));
+
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_RESUME:
+
+		break;
+	default:
+		pr_err("Invalid mode requested\n");
+		break;
+	}
+}
+
+static int clockevent_next_event(unsigned long cycles,
+				 struct clock_event_device *clk_event_dev)
+{
+	u16 val;
+
+	writew(cycles, gpt_base + LOAD(CLKEVT));
+
+	val = readw(gpt_base + CR(CLKEVT));
+	val |= CTRL_ENABLE | CTRL_INT_ENABLE;
+	writew(val, gpt_base + CR(CLKEVT));
+
+	return 0;
+}
+
+static irqreturn_t spear_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &clkevt;
+
+	writew(INT_STATUS, gpt_base + IR(CLKEVT));
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction spear_timer_irq = {
+	.name = "timer",
+	.flags = IRQF_DISABLED | IRQF_TIMER,
+	.handler = spear_timer_interrupt
+};
+
+static void __init spear_clockevent_init(void)
+{
+	u32 tick_rate;
+
+	/* program the prescaler */
+	writew(CTRL_PRESCALER16, gpt_base + CR(CLKEVT));
+
+	tick_rate = clk_get_rate(gpt_clk);
+	tick_rate >>= CTRL_PRESCALER16;
+
+	clockevent_set_clock(&clkevt, tick_rate);
+
+	clkevt.max_delta_ns = clockevent_delta2ns(0xfff0,
+			&clkevt);
+	clkevt.min_delta_ns = clockevent_delta2ns(3, &clkevt);
+
+	clkevt.cpumask = cpumask_of(0);
+
+	clockevents_register_device(&clkevt);
+
+	setup_irq(SPEAR_GPT0_CHAN0_IRQ, &spear_timer_irq);
+}
+
+void __init spear_setup_timer(void)
+{
+	struct clk *pll3_clk;
+
+	if (!request_mem_region(SPEAR_GPT0_BASE, SZ_1K, "gpt0")) {
+		pr_err("%s:cannot get IO addr\n", __func__);
+		return;
+	}
+
+	gpt_base = (void __iomem *)ioremap(SPEAR_GPT0_BASE, SZ_1K);
+	if (!gpt_base) {
+		pr_err("%s:ioremap failed for gpt\n", __func__);
+		goto err_mem;
+	}
+
+	gpt_clk = clk_get_sys("gpt0", NULL);
+	if (!gpt_clk) {
+		pr_err("%s:couldn't get clk for gpt\n", __func__);
+		goto err_iomap;
+	}
+
+	pll3_clk = clk_get(NULL, "pll3_48m_clk");
+	if (!pll3_clk) {
+		pr_err("%s:couldn't get PLL3 as parent for gpt\n", __func__);
+		goto err_iomap;
+	}
+
+	clk_set_parent(gpt_clk, pll3_clk);
+
+	spear_clockevent_init();
+	spear_clocksource_init();
+
+	return;
+
+err_iomap:
+	iounmap(gpt_base);
+
+err_mem:
+	release_mem_region(SPEAR_GPT0_BASE, SZ_1K);
+}
+
+struct sys_timer spear_sys_timer = {
+	.init = spear_setup_timer,
+};