diff mbox

[1/4] clocksource: mmp: add mmp timer driver

Message ID 1422865899-8152-2-git-send-email-chao.xie@marvell.com
State New, archived
Headers show

Commit Message

Chao Xie Feb. 2, 2015, 8:31 a.m. UTC
From: Chao Xie <chao.xie@marvell.com>

MMP timer is attached to APB bus, It has the following
limitation.
1. When get count of timer counter, it need some delay
   to get a stable count.
2. When set match register, it need disable the counter
   first, and enable it after set the match register.
   The disabling need wait for 2 clock cycle to take
   effect.

To improve above #1, shadow register for count is added.
To improve above #2, CRSR register is added for quick updating.

So there are three types of timer.
timer1: old timer.
timer2: old timer with shadow register.
timer3: old timer with shadow and CRSR register.

This timer driver will be used for many SOCes.
1. pxa168, pxa910, pxa988 pxa1088 have only timer1.
2. pxa1L88, pxa1U88 have timer1 and timer3.
3. pxa1928 has timer 2.

The driver supports DT and non-DT initialization.
The driver supports UP/SMP SOCes and 64 bit core.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
---
 .../devicetree/bindings/arm/mrvl/timer.txt         |  61 +-
 drivers/clocksource/Makefile                       |   1 +
 drivers/clocksource/timer-mmp.c                    | 837 +++++++++++++++++++++
 include/linux/mmp_timer.h                          |  40 +
 4 files changed, 933 insertions(+), 6 deletions(-)
 create mode 100644 drivers/clocksource/timer-mmp.c
 create mode 100644 include/linux/mmp_timer.h

Comments

Mark Rutland Feb. 2, 2015, 10:34 a.m. UTC | #1
On Mon, Feb 02, 2015 at 08:31:36AM +0000, Chao Xie wrote:
> From: Chao Xie <chao.xie@marvell.com>
> 
> MMP timer is attached to APB bus, It has the following
> limitation.
> 1. When get count of timer counter, it need some delay
>    to get a stable count.
> 2. When set match register, it need disable the counter
>    first, and enable it after set the match register.
>    The disabling need wait for 2 clock cycle to take
>    effect.
> 
> To improve above #1, shadow register for count is added.
> To improve above #2, CRSR register is added for quick updating.
> 
> So there are three types of timer.
> timer1: old timer.
> timer2: old timer with shadow register.
> timer3: old timer with shadow and CRSR register.
> 
> This timer driver will be used for many SOCes.
> 1. pxa168, pxa910, pxa988 pxa1088 have only timer1.
> 2. pxa1L88, pxa1U88 have timer1 and timer3.
> 3. pxa1928 has timer 2.
> 
> The driver supports DT and non-DT initialization.
> The driver supports UP/SMP SOCes and 64 bit core.
> 
> Signed-off-by: Chao Xie <chao.xie@marvell.com>
> ---
>  .../devicetree/bindings/arm/mrvl/timer.txt         |  61 +-
>  drivers/clocksource/Makefile                       |   1 +
>  drivers/clocksource/timer-mmp.c                    | 837 +++++++++++++++++++++
>  include/linux/mmp_timer.h                          |  40 +
>  4 files changed, 933 insertions(+), 6 deletions(-)
>  create mode 100644 drivers/clocksource/timer-mmp.c
>  create mode 100644 include/linux/mmp_timer.h
> 
> diff --git a/Documentation/devicetree/bindings/arm/mrvl/timer.txt b/Documentation/devicetree/bindings/arm/mrvl/timer.txt
> index 9a6e251..b49cb3e 100644
> --- a/Documentation/devicetree/bindings/arm/mrvl/timer.txt
> +++ b/Documentation/devicetree/bindings/arm/mrvl/timer.txt
> @@ -1,13 +1,62 @@
>  * Marvell MMP Timer controller
> 
> +Each timer have multiple counters, so the timer DT need include counter's
> +description.
> +
> +1. Timer
> +
>  Required properties:
> -- compatible : Should be "mrvl,mmp-timer".
> +- compatible : Should be "marvell,mmp-timer".
>  - reg : Address and length of the register set of timer controller.
> -- interrupts : Should be the interrupt number.
> +- clocks : The first clock is the fequency of the apb bus that the timer
> +  attached to. The second clock is the fast clock frequency of the timer.
> +  This frequency and fast clock are used to calculated delay
> +  loops for clock operations.

It might be a good idea to use clock-names for "apb" and "fast" and use
them in the driver.

> +
> +Optional properties:
> +- marvell,timer-has-crsr : This timer has CRSR register.
> +- marvell,timer-has-shadow : This timer has shadow register.
> +
> +2. Counter

The coutner nodes appear to be sub-nodes of the timer. That should be
stated explicitly.

> +
> +Required properties:
> +- compatible : It can be
> +      "marvell,timer-counter-clkevt" : The counter is used for clock event
> +                                       device.
> +      "marvell,timer-counter-clksrc" : The counter is used for clock source.
> +      "marvell,timer-counter-delay" : The counter is used for delay timer.

These are all Linux-internal details. I don't see why we should need
separate strings; Linux should be able to allocate these as appropriate
(and a single timer should be able to be both a clocksource and a delay
timer).

Is there any reason you envisage for having separate strings here? It
douesn't make sense to me to do so.

> +- marvell,timer-counter-id : The counter index in this timer.

It sounds like you could use reg for this, unless you have other
sub-nodes you'll need to instantiate?

> 
> -Example:
> -       timer0: timer@d4014000 {
> -               compatible = "mrvl,mmp-timer";
> -               reg = <0xd4014000 0x100>;
> +Optional properties:
> +- marvell,fast-clock : whether the counter use the fast-clock for counting.

It looks below like this is a policy decision, rather than a description
of the HW. When would you select the fast clock and when would you not?
Why can't the driver figure this out?

> +- interrupts : The interrupt for clock event device.
> +  Only valid for "marvell,timer-counter-clkevt".
> +- marvell,timer-counter-cpu : which CPU the counter is bound. Only valid for
> +  "marvell,timer-counter-clkevt".

This sounds like a policy decision, rather than a description of the HW.

Additionally, the number usage seems to be a Linux logical ID, rather
than a physical CPU ID. This is broken.

> +- marvell,timer-counter-broadcast : When this counter acts as clock event
> +  device. It is broadcast clock event device.
> +  Only valid for "marvell,timer-counter-clkevt".

This is a Linux-internal detail. There shouldn't be a binding for this.

> +- marvell,timer-counter-nodynirq : When this counter acts as broadcast clock
> +  event device, it cannot switch the IRQ of broadcast clock event to any CPU.
> +  Only valid for "marvell,timer-counter-clkevt".

Likewise. Why can't you change the affinity?

For all of the above properties, it sounds like what you actually
need/want to do is to check if the number of available timers >=
num_possible_cpus(), and if so, (dynamically) allocate a counter to each
CPU. If not, set up a timer as a broadcast source (with dynirq).

Thanks,
Mark.
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/arm/mrvl/timer.txt b/Documentation/devicetree/bindings/arm/mrvl/timer.txt
index 9a6e251..b49cb3e 100644
--- a/Documentation/devicetree/bindings/arm/mrvl/timer.txt
+++ b/Documentation/devicetree/bindings/arm/mrvl/timer.txt
@@ -1,13 +1,62 @@ 
 * Marvell MMP Timer controller
 
+Each timer have multiple counters, so the timer DT need include counter's
+description.
+
+1. Timer
+
 Required properties:
-- compatible : Should be "mrvl,mmp-timer".
+- compatible : Should be "marvell,mmp-timer".
 - reg : Address and length of the register set of timer controller.
-- interrupts : Should be the interrupt number.
+- clocks : The first clock is the fequency of the apb bus that the timer
+  attached to. The second clock is the fast clock frequency of the timer.
+  This frequency and fast clock are used to calculated delay
+  loops for clock operations.
+
+Optional properties:
+- marvell,timer-has-crsr : This timer has CRSR register.
+- marvell,timer-has-shadow : This timer has shadow register.
+
+2. Counter
+
+Required properties:
+- compatible : It can be
+      "marvell,timer-counter-clkevt" : The counter is used for clock event
+                                       device.
+      "marvell,timer-counter-clksrc" : The counter is used for clock source.
+      "marvell,timer-counter-delay" : The counter is used for delay timer.
+- marvell,timer-counter-id : The counter index in this timer.
 
-Example:
-	timer0: timer@d4014000 {
-		compatible = "mrvl,mmp-timer";
-		reg = <0xd4014000 0x100>;
+Optional properties:
+- marvell,fast-clock : whether the counter use the fast-clock for counting.
+- interrupts : The interrupt for clock event device.
+  Only valid for "marvell,timer-counter-clkevt".
+- marvell,timer-counter-cpu : which CPU the counter is bound. Only valid for
+  "marvell,timer-counter-clkevt".
+- marvell,timer-counter-broadcast : When this counter acts as clock event
+  device. It is broadcast clock event device.
+  Only valid for "marvell,timer-counter-clkevt".
+- marvell,timer-counter-nodynirq : When this counter acts as broadcast clock
+  event device, it cannot switch the IRQ of broadcast clock event to any CPU.
+  Only valid for "marvell,timer-counter-clkevt".
+
+3. Examples
+
+timer0: timer@d4014000 {
+	compatible = "marvell,mmp-timer";
+	reg = <0xd4014000 0xc8>;
+	clocks = <&soc_clocks MMP2_PLL1_24>, <&soc_closk MMP2_CLK_TIMER>;
+	status = "okay";
+
+	counter0 {
+		compatible = "marvell,timer-counter-clkevt";
 		interrupts = <13>;
+		marvell,timer-counter-id = <0>;
+		marvell,timer-counter-cpu = <0>;
+	};
+
+	counter1 {
+		compatible = "marvell,timer-counter-clksrc";
+		marvell,timer-counter-id = <1>;
 	};
+};
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 94d90b2..6a66d4d 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_ORION_TIMER)	+= time-orion.o
 obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835_timer.o
 obj-$(CONFIG_ARCH_CLPS711X)	+= clps711x-timer.o
 obj-$(CONFIG_ARCH_MARCO)	+= timer-marco.o
+obj-$(CONFIG_ARCH_MMP)		+= timer-mmp.o
 obj-$(CONFIG_ARCH_MOXART)	+= moxart_timer.o
 obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
 obj-$(CONFIG_ARCH_PXA)		+= pxa_timer.o
diff --git a/drivers/clocksource/timer-mmp.c b/drivers/clocksource/timer-mmp.c
new file mode 100644
index 0000000..b6a9ce1
--- /dev/null
+++ b/drivers/clocksource/timer-mmp.c
@@ -0,0 +1,837 @@ 
+/*
+ * driver/clocksource/timer-mmp.c
+ *
+ *   Support for clocksource and clockevents
+ *
+ * Copyright (C) 2008 Marvell International Ltd.
+ * All rights reserved.
+ *
+ *   2008-04-11: Jason Chagas <Jason.chagas@marvell.com>
+ *   2008-10-08: Bin Yang <bin.yang@marvell.com>
+ *
+ * The timers module actually includes three timers, each timer with up to
+ * three match comparators. Timer #0 is used here in free-running mode as
+ * the clock source, and match comparator #1 used as clock event device.
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/mmp_timer.h>
+#include <linux/clockchips.h>
+#include <linux/sched_clock.h>
+#include <linux/clk.h>
+
+#define TMR_CCR		(0x0000)
+#define TMR_TN_MM(n, m)	(0x0004 + ((n) << 3) + (((n) + (m)) << 2))
+#define TMR_CR(n)	(0x0028 + ((n) << 2))
+#define TMR_SR(n)	(0x0034 + ((n) << 2))
+#define TMR_IER(n)	(0x0040 + ((n) << 2))
+#define TMR_PLVR(n)	(0x004c + ((n) << 2))
+#define TMR_PLCR(n)	(0x0058 + ((n) << 2))
+#define TMR_WMER	(0x0064)
+#define TMR_WMR		(0x0068)
+#define TMR_WVR		(0x006c)
+#define TMR_WSR		(0x0070)
+#define TMR_ICR(n)	(0x0074 + ((n) << 2))
+#define TMR_WICR	(0x0080)
+#define TMR_CER		(0x0084)
+#define TMR_CMR		(0x0088)
+#define TMR_ILR(n)	(0x008c + ((n) << 2))
+#define TMR_WCR		(0x0098)
+#define TMR_WFAR	(0x009c)
+#define TMR_WSAR	(0x00A0)
+#define TMR_CVWR(n)	(0x00A4 + ((n) << 2))
+#define TMR_CRSR        (0x00B0)
+
+#define TMR_CCR_CS_0(x)	(((x) & 0x3) << 0)
+#define TMR_CCR_CS_1(x)	(((x) & 0x3) << 2)
+#define TMR_CCR_CS_2(x)	(((x) & 0x3) << 5)
+
+#define MAX_EVT_NUM		5
+
+#define MAX_DELTA		(0xfffffffe)
+#define MIN_DELTA		(5)
+
+#define MMP_MAX_COUNTER		3
+#define MMP_MAX_TIMER		4
+
+#define TMR_CER_COUNTER(cid)	(1 << (cid))
+#define MMP_ALL_COUNTERS	((1 << MMP_MAX_COUNTER) - 1)
+
+#define MMP_TIMER_CLOCK_32KHZ	32768
+#define MMP_TIMER_CLOCK_1KHZ	1000
+
+struct mmp_timer;
+struct mmp_timer_counter {
+	unsigned int id;
+	unsigned int usage;
+	unsigned int cnt_freq;
+	int cpu;
+	int loop_delay;
+	struct mmp_timer *timer;
+};
+
+struct mmp_timer {
+	unsigned int id;
+	void __iomem *base;
+	struct mmp_timer_counter counters[MMP_MAX_COUNTER];
+	unsigned int flag;
+	int loop_delay_fastclk;
+	unsigned int fc_freq;
+	/* lock to protect hw operation. */
+	spinlock_t tm_lock;
+};
+
+struct mmp_timer_clkevt {
+	struct mmp_timer_counter *counter;
+	struct clock_event_device ced;
+	struct irqaction irqa;
+	struct notifier_block nb;
+};
+
+struct mmp_timer_clksrc {
+	struct mmp_timer_counter *counter;
+	struct clocksource cs;
+};
+
+#ifdef CONFIG_ARM
+struct mmp_timer_dclk {
+	struct mmp_timer_counter *counter;
+	struct delay_timer *dt;
+};
+static struct mmp_timer_dclk *dclk;
+#endif
+
+static struct mmp_timer *mmp_timers[MMP_MAX_TIMER];
+static struct mmp_timer_clksrc *clksrc;
+
+static int timer_counter_switch_clock(int tid, int cid, unsigned int freq)
+{
+	struct mmp_timer *tm = mmp_timers[tid];
+	u32 ccr, mask;
+
+	ccr = readl_relaxed(tm->base + TMR_CCR);
+
+	if (cid == 0)
+		mask = TMR_CCR_CS_0(3);
+	else if (cid == 1)
+		mask = TMR_CCR_CS_1(3);
+	else
+		mask = TMR_CCR_CS_2(3);
+
+	ccr &= ~mask;
+
+	if (freq == MMP_TIMER_CLOCK_32KHZ) {
+		if (cid == 2)
+			ccr |= TMR_CCR_CS_2(2);
+		else if (cid == 1)
+			ccr |= TMR_CCR_CS_1(1);
+		else if (cid == 0)
+			ccr |= TMR_CCR_CS_0(1);
+	} else if (freq == MMP_TIMER_CLOCK_1KHZ) {
+		if (cid == 2)
+			ccr |= TMR_CCR_CS_2(1);
+		else if (cid == 1)
+			ccr |= TMR_CCR_CS_1(2);
+	} else if (freq == tm->fc_freq) {
+		if (cid == 2)
+			ccr |= TMR_CCR_CS_2(0);
+		else if (cid == 1)
+			ccr |= TMR_CCR_CS_1(0);
+		else if (cid == 0)
+			ccr |= TMR_CCR_CS_0(0);
+	} else {
+		pr_err("Timer %d:%d: invalid clock rate %d\n", tid, cid, freq);
+		return -EINVAL;
+	}
+
+	writel_relaxed(ccr, tm->base + TMR_CCR);
+
+	return 0;
+}
+
+static void timer_counter_disable(struct mmp_timer_counter *cnt)
+{
+	struct mmp_timer *tm = cnt->timer;
+	int delay = tm->loop_delay_fastclk;
+	u32 cer;
+
+	/*
+	 * Stop the counter will need multiple timer clock to take effect.
+	 * Some operations can only be done when counter is disabled. So
+	 * add delay here.
+	 */
+	/* Step1: disable counter */
+	cer = readl_relaxed(tm->base + TMR_CER);
+	writel_relaxed(cer & ~(1 << cnt->id), tm->base + TMR_CER);
+
+	/*
+	 * Step2: switch to fast clock, so the delay can be completed
+	 * quickly.
+	 */
+	if (cnt->cnt_freq != tm->fc_freq)
+		timer_counter_switch_clock(tm->id, cnt->id, tm->fc_freq);
+
+	/*
+	 * Step3: Loop for multiple timer cycles. We do it by clearing
+	 * pending interrupt status.
+	 */
+	while (delay--)
+		writel_relaxed(0x1, tm->base + TMR_ICR(cnt->id));
+}
+
+static void timer_counter_enable(struct mmp_timer_counter *cnt)
+{
+	struct mmp_timer *tm = cnt->timer;
+	u32 cer;
+
+	/* Switch to original clock */
+	if (cnt->cnt_freq != tm->fc_freq)
+		timer_counter_switch_clock(tm->id, cnt->id, cnt->cnt_freq);
+
+	/* Enable timer */
+	cer = readl_relaxed(tm->base + TMR_CER);
+	writel_relaxed(cer | (1 << cnt->id), tm->base + TMR_CER);
+}
+
+static inline uint32_t timer_read(struct mmp_timer_counter *cnt)
+{
+	struct mmp_timer *tm = cnt->timer;
+	int has_shadow = tm->flag & MMP_TIMER_FLAG_SHADOW;
+	int delay = 3;
+	u32 val1, val2;
+
+	if (has_shadow)
+		return readl_relaxed(tm->base + TMR_CR(cnt->id));
+
+	if (cnt->cnt_freq != tm->fc_freq) {
+		/* slow clock */
+		do {
+			val1 = readl_relaxed(tm->base + TMR_CR(cnt->id));
+			val2 = readl_relaxed(tm->base + TMR_CR(cnt->id));
+		} while (val2 != val1);
+	} else {
+		/* fast clock */
+		writel_relaxed(1, tm->base + TMR_CVWR(cnt->id));
+		while (delay--)
+			val1 = readl_relaxed(tm->base +
+					TMR_CVWR(cnt->id));
+	}
+
+	return val1;
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *c = dev_id;
+	struct mmp_timer_clkevt *evt;
+	struct mmp_timer_counter *counter;
+	unsigned int cnt;
+	unsigned long flags;
+	void __iomem *base;
+	int has_crsr;
+
+	evt = container_of(c, struct mmp_timer_clkevt, ced);
+	counter = evt->counter;
+	cnt = counter->id;
+	base = counter->timer->base;
+	has_crsr = counter->timer->flag & MMP_TIMER_FLAG_CRSR;
+
+	spin_lock_irqsave(&(counter->timer->tm_lock), flags);
+	/* We only use match #0 for the counter. */
+	if (readl_relaxed(base + TMR_SR(cnt)) & 0x1) {
+		if (!has_crsr)
+			timer_counter_disable(counter);
+
+		/* Disable the interrupt. */
+		writel_relaxed(0x00, base + TMR_IER(cnt));
+		/* Clear interrupt status */
+		writel_relaxed(0x01, base + TMR_ICR(cnt));
+
+		spin_unlock_irqrestore(&(counter->timer->tm_lock), flags);
+
+		c->event_handler(c);
+
+		return IRQ_HANDLED;
+	}
+
+	spin_unlock_irqrestore(&(counter->timer->tm_lock), flags);
+
+	return IRQ_NONE;
+}
+
+static int timer_set_next_event(unsigned long delta,
+				struct clock_event_device *dev)
+{
+	struct mmp_timer_counter *cnt;
+	struct mmp_timer_clkevt *evt;
+	unsigned long flags;
+	unsigned int cid;
+	u32 cer, crsr;
+	void __iomem *base;
+	int delay, has_crsr;
+
+	evt = container_of(dev, struct mmp_timer_clkevt, ced);
+	cnt = evt->counter;
+	cid = cnt->id;
+	base = cnt->timer->base;
+	has_crsr = cnt->timer->flag & MMP_TIMER_FLAG_CRSR;
+
+	spin_lock_irqsave(&(cnt->timer->tm_lock), flags);
+	if (has_crsr) {
+		/*
+		 * Use TMR_CRSR to restart the counter and make match
+		 * register take effect. This bit should be 0 before
+		 * set it again.
+		 * The polling loop is defined by loop_delay.
+		 */
+		delay = cnt->loop_delay;
+		do {
+			crsr = readl_relaxed(base + TMR_CRSR);
+			delay--;
+		} while ((crsr & (1 << cid)) && delay > 0);
+
+		BUG_ON(delay <= 0);
+
+		writel_relaxed(delta - 1, base + TMR_TN_MM(cid, 0));
+		/*
+		 * After counter is restart, clear the interrupt status for
+		 * safe, and re-enable the interrupt for match #0.
+		 */
+		writel_relaxed(0x01, base + TMR_ICR(cid));
+		writel_relaxed(0x01, base + TMR_IER(cid));
+		writel_relaxed((1 << cid), base + TMR_CRSR);
+	} else {
+		cer = readl_relaxed(base + TMR_CER);
+
+		/* If the timer counter is enabled, first disable it. */
+		if (cer & (1 << cid))
+			timer_counter_disable(cnt);
+
+		/* Setup new counter value */
+		writel_relaxed(delta - 1, base + TMR_TN_MM(cid, 0));
+
+		/* enable the matching interrupt */
+		writel_relaxed(0x1, base + TMR_IER(cid));
+
+		timer_counter_enable(cnt);
+	}
+	spin_unlock_irqrestore(&(cnt->timer->tm_lock), flags);
+
+	return 0;
+}
+
+static void timer_set_mode(enum clock_event_mode mode,
+			   struct clock_event_device *dev)
+{
+	unsigned long flags;
+	unsigned int cnt;
+	struct mmp_timer_counter *counter;
+	struct mmp_timer_clkevt *evt;
+	void __iomem *base;
+
+	evt = container_of(dev, struct mmp_timer_clkevt, ced);
+	counter = evt->counter;
+	cnt = counter->id;
+	base = counter->timer->base;
+
+	spin_lock_irqsave(&(counter->timer->tm_lock), flags);
+	switch (mode) {
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		timer_counter_disable(counter);
+		break;
+	case CLOCK_EVT_MODE_RESUME:
+	case CLOCK_EVT_MODE_PERIODIC:
+	case CLOCK_EVT_MODE_ONESHOT:
+		timer_counter_enable(counter);
+		break;
+	}
+	spin_unlock_irqrestore(&(counter->timer->tm_lock), flags);
+}
+
+static cycle_t clksrc_read(struct clocksource *cs)
+{
+	return timer_read(clksrc->counter);
+}
+
+static u64 notrace mmp_read_sched_clock(void)
+{
+	return timer_read(clksrc->counter);
+}
+
+#ifdef CONFIG_ARM
+static unsigned long d_read_current_timer(void)
+{
+	return timer_read(dclk->counter);
+}
+
+static struct delay_timer d_timer = {
+	.read_current_timer	= d_read_current_timer,
+};
+#endif
+
+static int mmp_timer_cpu_notify(struct notifier_block *self,
+				unsigned long action, void *hcpu)
+{
+	struct mmp_timer_clkevt *evt;
+	struct mmp_timer_counter *cnt;
+
+	evt = container_of(self, struct mmp_timer_clkevt, nb);
+	cnt = evt->counter;
+
+	if (cnt->cpu != (unsigned long)hcpu)
+		return NOTIFY_OK;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_STARTING:
+		clockevents_config_and_register(&evt->ced,
+						cnt->cnt_freq,
+						MIN_DELTA, MAX_DELTA);
+		break;
+	case CPU_ONLINE:
+		irq_set_affinity(evt->ced.irq, evt->ced.cpumask);
+		enable_irq(evt->ced.irq);
+		break;
+	case CPU_DYING:
+		clockevents_set_mode(&evt->ced,
+				     CLOCK_EVT_MODE_SHUTDOWN);
+		disable_irq(evt->ced.irq);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+int __init mmp_timer_init(int tid, void __iomem *base,
+			  unsigned int flag, unsigned int fc_freq,
+			  unsigned int apb_freq)
+{
+	struct mmp_timer *tm = mmp_timers[tid];
+	u32 tmp, delay;
+	int cid;
+
+	if (tm)
+		return -EINVAL;
+
+	tm = kzalloc(sizeof(*tm), GFP_KERNEL);
+	if (!tm)
+		return -ENOMEM;
+
+	/*
+	 * The calculation formula for the loop cycle is:
+	 *
+	 * (1) need wait for 2 timer's clock cycle:
+	 *        1             2
+	 *     ------- x 2 = -------
+	 *     fc_freq       fc_freq
+	 *
+	 * (2) convert to apb clock cycle:
+	 *        2          1        apb_freq * 2
+	 *     ------- / -------- = ----------------
+	 *     fc_freq   apb_freq       fc_freq
+	 *
+	 * (3) every apb register's accessing will take 8 apb clock cycle,
+	 *     also consider add extral one more time for safe way;
+	 *     so finally need loop times for the apb register accessing:
+	 *
+	 *       (apb_freq * 2)
+	 *     ------------------ / 8 + 1
+	 *          fc_freq
+	 */
+	delay = ((apb_freq * 2) / fc_freq / 8) + 1;
+	pr_debug("Timer %d: loop_delay_fastclk is %d\n", tid, delay);
+
+	tm->id = tid;
+	tm->base = base;
+	tm->flag = flag;
+	tm->loop_delay_fastclk = delay;
+	tm->fc_freq = fc_freq;
+	spin_lock_init(&(tm->tm_lock));
+
+	mmp_timers[tid] = tm;
+
+	for (cid = 0; cid < MMP_MAX_COUNTER; cid++) {
+		tm->counters[cid].id = cid;
+		tm->counters[cid].timer = tm;
+
+		/* We will disable all counters. Switch to fastclk first. */
+		timer_counter_switch_clock(tid, cid, fc_freq);
+	}
+
+	/* disalbe all counters */
+	tmp = readl_relaxed(base + TMR_CER) & ~MMP_ALL_COUNTERS;
+	writel_relaxed(tmp, base + TMR_CER);
+
+	/* disable matching interrupt */
+	writel_relaxed(0x00, base + TMR_IER(0));
+	writel_relaxed(0x00, base + TMR_IER(1));
+	writel_relaxed(0x00, base + TMR_IER(2));
+
+	while (delay--) {
+		/* Clear pending interrupt status */
+		writel_relaxed(0x1, base + TMR_ICR(0));
+		writel_relaxed(0x1, base + TMR_ICR(1));
+		writel_relaxed(0x1, base + TMR_ICR(2));
+		writel_relaxed(tmp, base + TMR_CER);
+	}
+
+	return 0;
+}
+
+static int __init mmp_timer_counter_hw_init(struct mmp_timer *tm, int cid,
+					    unsigned int freq)
+{
+	u32 tmp, delay;
+	unsigned int ratio;
+	int ret;
+
+	ret = timer_counter_switch_clock(tm->id, cid, freq);
+	if (ret)
+		return ret;
+
+	ratio = tm->fc_freq / tm->counters[cid].cnt_freq;
+	tm->counters[cid].cnt_freq = freq;
+	tm->counters[cid].loop_delay = tm->loop_delay_fastclk * ratio;
+
+	/* set timer to free-running mode */
+	tmp = readl_relaxed(tm->base + TMR_CMR) | TMR_CER_COUNTER(cid);
+	writel_relaxed(tmp, tm->base + TMR_CMR);
+
+	/* free-running */
+	writel_relaxed(0x0, tm->base + TMR_PLCR(cid));
+	/* clear status */
+	writel_relaxed(0x7, tm->base + TMR_ICR(cid));
+
+	/* enable counter */
+	tmp = readl_relaxed(tm->base + TMR_CER) | TMR_CER_COUNTER(cid);
+	writel_relaxed(tmp, tm->base + TMR_CER);
+
+	delay = tm->counters[cid].loop_delay;
+	while (delay--)
+		writel_relaxed(tmp, tm->base + TMR_CER);
+
+	return 0;
+}
+
+int __init mmp_counter_clocksource_init(int tid, int cid, unsigned int freq)
+{
+	struct mmp_timer *mt = mmp_timers[tid];
+	int ret;
+
+	if (!mt)
+		return -EINVAL;
+
+	if (cid < 0 || cid >= MMP_MAX_COUNTER)
+		return -EINVAL;
+
+	if (clksrc) {
+		pr_err("One clksrc has already been registered!\n");
+		return -EINVAL;
+	}
+	clksrc = kzalloc(sizeof(*clksrc), GFP_KERNEL);
+	if (!clksrc)
+		return -ENOMEM;
+
+	mt->counters[cid].usage |= MMP_TIMER_COUNTER_CLKSRC;
+	mt->counters[cid].cnt_freq = freq;
+
+	clksrc->counter = &mt->counters[cid];
+	clksrc->cs.name = "clocksource-mmp";
+	clksrc->cs.rating = 200;
+	clksrc->cs.read = clksrc_read;
+	clksrc->cs.mask = CLOCKSOURCE_MASK(32);
+	clksrc->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	sched_clock_register(mmp_read_sched_clock, 32, freq);
+
+	clocksource_register_hz(&(clksrc->cs), freq);
+
+	ret = mmp_timer_counter_hw_init(mt, cid, freq);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int __init mmp_counter_timer_delay_init(int tid, int cid, unsigned int freq)
+{
+#ifdef CONFIG_ARM
+	struct mmp_timer *mt = mmp_timers[tid];
+	int ret;
+
+	if (!mt)
+		return -EINVAL;
+
+	if (cid < 0 || cid >= MMP_MAX_COUNTER)
+		return -EINVAL;
+
+	if (dclk) {
+		pr_err("Delay clock has already been registered!\n");
+		return -EINVAL;
+	}
+	dclk = kzalloc(sizeof(*dclk), GFP_KERNEL);
+	if (!dclk)
+		return -ENOMEM;
+
+	mt->counters[cid].usage |= MMP_TIMER_COUNTER_DELAY;
+	mt->counters[cid].cnt_freq = freq;
+
+	dclk->counter = &mt->counters[cid];
+	dclk->dt = &d_timer;
+	d_timer.freq = freq;
+	register_current_timer_delay(&d_timer);
+
+	ret = mmp_timer_counter_hw_init(mt, cid, freq);
+	if (ret)
+		return ret;
+#endif
+	return 0;
+}
+
+int __init mmp_counter_clockevent_init(int tid, int cid, int irq,
+				       int freq, int dynirq, unsigned int cpu)
+{
+	struct mmp_timer *mt = mmp_timers[tid];
+	struct mmp_timer_clkevt *clkevt;
+	int broadcast = 0;
+	int ret;
+
+	if (!mt)
+		return -EINVAL;
+
+	if (cid < 0 || cid >= MMP_MAX_COUNTER)
+		return -EINVAL;
+
+	if (cpu == MMP_TIMER_ALL_CPU)
+		broadcast = 1;
+	else if (cpu >= num_possible_cpus())
+		return -EINVAL;
+
+	mt->counters[cid].usage |= MMP_TIMER_COUNTER_CLKEVT;
+	mt->counters[cid].cnt_freq = freq;
+	mt->counters[cid].cpu = cpu;
+
+	clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
+	if (!clkevt)
+		return -ENOMEM;
+	clkevt->counter = &mt->counters[cid];
+	clkevt->ced.name = "clockevent-mmp";
+	clkevt->ced.features = CLOCK_EVT_FEAT_ONESHOT;
+	clkevt->ced.rating = 200;
+	clkevt->ced.set_next_event = timer_set_next_event;
+	clkevt->ced.set_mode = timer_set_mode;
+	clkevt->ced.irq = irq;
+
+	clkevt->irqa.flags = IRQF_TIMER | IRQF_IRQPOLL;
+	clkevt->irqa.handler = timer_interrupt;
+	clkevt->irqa.dev_id = &(clkevt->ced);
+
+	ret = mmp_timer_counter_hw_init(mt, cid, freq);
+	if (ret)
+		return ret;
+
+	if (broadcast) {
+		clkevt->irqa.name = "broadcast-timer";
+		if (dynirq)
+			clkevt->ced.features |= CLOCK_EVT_FEAT_DYNIRQ;
+		clkevt->ced.cpumask = cpu_possible_mask;
+		setup_irq(clkevt->ced.irq, &(clkevt->irqa));
+		clockevents_config_and_register(&clkevt->ced,
+						freq, MIN_DELTA, MAX_DELTA);
+	} else {
+		clkevt->irqa.name = "local-timer";
+		clkevt->ced.cpumask = cpumask_of(cpu);
+		clkevt->nb.notifier_call = mmp_timer_cpu_notify;
+		register_cpu_notifier(&clkevt->nb);
+		setup_irq(clkevt->ced.irq, &(clkevt->irqa));
+		/* Enable clock event device for boot CPU. */
+		if (cpu == smp_processor_id()) {
+			clockevents_config_and_register(&clkevt->ced,
+							freq, MIN_DELTA,
+							MAX_DELTA);
+			/* Only online CPU can be set affinity. */
+			irq_set_affinity(clkevt->ced.irq, cpumask_of(cpu));
+		} else {
+			/* disable none boot CPU's irq at first */
+			disable_irq(clkevt->ced.irq);
+		}
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+
+struct of_device_id mmp_counter_of_id[] = {
+	{
+		.compatible = "marvell,timer-counter-clksrc",
+		.data = (void *)MMP_TIMER_COUNTER_CLKSRC,
+	},
+	{
+		.compatible = "marvell,timer-counter-clkevt",
+		.data = (void *)MMP_TIMER_COUNTER_CLKEVT,
+	},
+	{
+		.compatible = "marvell,timer-counter-delay",
+		.data = (void *)MMP_TIMER_COUNTER_DELAY,
+	},
+	{ },
+};
+
+static int __init mmp_of_counter_init(struct device_node *np, int tid,
+				      unsigned int usage)
+{
+	int irq, ret, dynirq;
+	unsigned int cid, freq, cpu;
+	struct mmp_timer *mt = mmp_timers[tid];
+
+	if (!np)
+		return -EINVAL;
+
+	if (of_property_read_bool(np, "marvell,fast-clock"))
+		freq = mt->fc_freq;
+	else
+		freq = MMP_TIMER_CLOCK_32KHZ;
+
+	ret = of_property_read_u32(np, "marvell,timer-counter-id", &cid);
+	if (ret) {
+		pr_err("Timer %d: fail to get counter id\n", tid);
+		return ret;
+	}
+
+	if (usage & MMP_TIMER_COUNTER_DELAY) {
+		ret = mmp_counter_timer_delay_init(tid, cid, freq);
+		if (ret) {
+			pr_err("Timer %d:%d: fail to create delay timer\n",
+			       tid, cid);
+			return ret;
+		}
+	}
+
+	if (usage & MMP_TIMER_COUNTER_CLKSRC) {
+		ret = mmp_counter_clocksource_init(tid, cid, freq);
+		if (ret) {
+			pr_err("Timer %d:%d: fail to create clksrc\n",
+			       tid, cid);
+			return ret;
+		}
+	}
+	if (usage & MMP_TIMER_COUNTER_CLKEVT) {
+		if (of_property_read_bool(np,
+					  "marvell,timer-counter-broadcast")) {
+			cpu = MMP_TIMER_ALL_CPU;
+		} else {
+			ret = of_property_read_u32(np,
+						   "marvell,timer-counter-cpu",
+						   &cpu);
+			if (ret) {
+				pr_err("Timer %d:%d: fail to get cpu\n",
+				       tid, cid);
+				return ret;
+			}
+		}
+		dynirq = !of_property_read_bool(np,
+				"marvell,timer-counter-nodynirq");
+		irq = irq_of_parse_and_map(np, 0);
+		ret = mmp_counter_clockevent_init(tid, cid,
+						  irq, freq, dynirq, cpu);
+		if (ret) {
+			pr_err("Timer %d:%d: fail to create clkevt\n",
+			       tid, cid);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void __init mmp_of_timer_init(struct device_node *np)
+{
+	int tid;
+	unsigned int flag, fc_freq, apb_freq;
+	struct clk *apb_clk, *fast_clk;
+	void __iomem *base;
+	struct device_node *child_np;
+	const struct of_device_id *match;
+	int ret = 0;
+
+	for (tid = 0; tid < MMP_MAX_TIMER; tid++)
+		if (mmp_timers[tid] == NULL)
+			break;
+
+	if (tid >= MMP_MAX_TIMER)
+		return;
+
+	apb_clk = of_clk_get(np, 0);
+	if (!apb_clk)
+		return;
+	apb_freq = clk_get_rate(apb_clk);
+
+	fast_clk = of_clk_get(np, 1);
+	if (!fast_clk)
+		return;
+	fc_freq = clk_get_rate(fast_clk);
+
+	clk_prepare_enable(fast_clk);
+
+	/* timer initialization */
+	base = of_iomap(np, 0);
+	if (!base) {
+		pr_err("Timer: fail to map register space\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	flag = 0;
+	if (of_property_read_bool(np, "marvell,timer-has-crsr"))
+		flag |= MMP_TIMER_FLAG_CRSR;
+
+	if (of_property_read_bool(np, "marvell,timer-has-shadow"))
+		flag |= MMP_TIMER_FLAG_SHADOW;
+
+	ret = mmp_timer_init(tid, base, flag, fc_freq, apb_freq);
+	if (ret)
+		goto out;
+
+	/*
+	 * If device node is marked as not available,
+	 * we then don't try to enable the counter again
+	 */
+	if (!of_device_is_available(np)) {
+		pr_warn("Timer %d: is not used\n", tid);
+		return;
+	}
+
+	/* counter initialization */
+	for_each_child_of_node(np, child_np) {
+		match = of_match_node(mmp_counter_of_id, child_np);
+		ret = mmp_of_counter_init(child_np, tid,
+					  (unsigned int)match->data);
+		if (ret)
+			goto out;
+	}
+
+	return;
+out:
+	if (ret)
+		pr_err("Failed to get timer from dtb with error:%d\n", ret);
+}
+
+CLOCKSOURCE_OF_DECLARE(mmp_timer, "marvell,mmp-timer", mmp_of_timer_init);
+#endif
diff --git a/include/linux/mmp_timer.h b/include/linux/mmp_timer.h
new file mode 100644
index 0000000..6ca7f80
--- /dev/null
+++ b/include/linux/mmp_timer.h
@@ -0,0 +1,40 @@ 
+/*
+ * mmp_timer: Soc timer driver for mmp architecture.
+ *
+ * Copyright (C) 2008 Marvell International Ltd.
+ *
+ * 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.
+ */
+
+#ifndef __LINUX_MMP_TIMER_H__
+#define __LINUX_MMP_TIMER_H__
+
+/* timer flag bit definition */
+/* bit[0]: MMP_TIMER_FLAG_SHADOW
+ *         Indicate if the timer has shadow registers. If it has,
+ *         counter could be read out directly.
+ * bit[1]: MMP_TIMER_FLAG_CRSR
+ *         Indicate if timer has CRSR register. If it has,
+ *         counter could be restarted by directly writing CRSR.
+ */
+#define MMP_TIMER_FLAG_SHADOW	(1 << 0)
+#define MMP_TIMER_FLAG_CRSR	(1 << 1)
+
+#define MMP_TIMER_COUNTER_CLKSRC	(1 << 0)
+#define MMP_TIMER_COUNTER_CLKEVT	(1 << 1)
+#define MMP_TIMER_COUNTER_DELAY		(1 << 2)
+
+#define MMP_TIMER_ALL_CPU	(0xFFFFFFFF)
+
+int __init mmp_timer_init(int id, void __iomem *base,
+			  unsigned int flag, unsigned int fc_freq,
+			  unsigned int apb_freq);
+
+int __init mmp_counter_clocksource_init(int tid, int cid, unsigned int freq);
+int __init mmp_counter_timer_delay_init(int tid, int cid, unsigned int freq);
+int __init mmp_counter_clockevent_init(int tid, int cid, int irq,
+				       int freq, int dynirq, unsigned int cpu);
+
+#endif /* __LINUX_MMP_TIMER_H__ */