drivers/clocksource/timer-davinci.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * TI DaVinci clocksource driver
  *
  * Copyright (C) 2019 Texas Instruments
  * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
  * (with tiny parts adopted from code by Kevin Hilman <khilman@baylibre.com>)
  */

 #include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/sched_clock.h>

 #include <clocksource/timer-davinci.h>

 #undef pr_fmt
 #define pr_fmt(fmt) "%s: " fmt, __func__

 #define DAVINCI_TIMER_REG_TIM12			0x10
 #define DAVINCI_TIMER_REG_TIM34			0x14
 #define DAVINCI_TIMER_REG_PRD12			0x18
 #define DAVINCI_TIMER_REG_PRD34			0x1c
 #define DAVINCI_TIMER_REG_TCR			0x20
 #define DAVINCI_TIMER_REG_TGCR			0x24

 #define DAVINCI_TIMER_TIMMODE_MASK		GENMASK(3, 2)
 #define DAVINCI_TIMER_RESET_MASK		GENMASK(1, 0)
 #define DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED	BIT(2)
 #define DAVINCI_TIMER_UNRESET			GENMASK(1, 0)

 #define DAVINCI_TIMER_ENAMODE_MASK		GENMASK(1, 0)
 #define DAVINCI_TIMER_ENAMODE_DISABLED		0x00
 #define DAVINCI_TIMER_ENAMODE_ONESHOT		BIT(0)
 #define DAVINCI_TIMER_ENAMODE_PERIODIC		BIT(1)

 #define DAVINCI_TIMER_ENAMODE_SHIFT_TIM12	6
 #define DAVINCI_TIMER_ENAMODE_SHIFT_TIM34	22

 #define DAVINCI_TIMER_MIN_DELTA			0x01
 #define DAVINCI_TIMER_MAX_DELTA			0xfffffffe

 #define DAVINCI_TIMER_CLKSRC_BITS		32

 #define DAVINCI_TIMER_TGCR_DEFAULT \
 		(DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED | DAVINCI_TIMER_UNRESET)

 struct davinci_clockevent {
 	struct clock_event_device dev;
 	void __iomem *base;
 	unsigned int cmp_off;
 };

 /*
  * This must be globally accessible by davinci_timer_read_sched_clock(), so
  * let's keep it here.
  */
 static struct {
 	struct clocksource dev;
 	void __iomem *base;
 	unsigned int tim_off;
 } davinci_clocksource;

 static struct davinci_clockevent *
 to_davinci_clockevent(struct clock_event_device *clockevent)
 {
 	return container_of(clockevent, struct davinci_clockevent, dev);
 }

 static unsigned int
 davinci_clockevent_read(struct davinci_clockevent *clockevent,
 			unsigned int reg)
 {
 	return readl_relaxed(clockevent->base + reg);
 }

 static void davinci_clockevent_write(struct davinci_clockevent *clockevent,
 				     unsigned int reg, unsigned int val)
 {
 	writel_relaxed(val, clockevent->base + reg);
 }

 static void davinci_tim12_shutdown(void __iomem *base)
 {
 	unsigned int tcr;

 	tcr = DAVINCI_TIMER_ENAMODE_DISABLED <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
 	/*
 	 * This function is only ever called if we're using both timer
 	 * halves. In this case TIM34 runs in periodic mode and we must
 	 * not modify it.
 	 */
 	tcr |= DAVINCI_TIMER_ENAMODE_PERIODIC <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;

 	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
 }

 static void davinci_tim12_set_oneshot(void __iomem *base)
 {
 	unsigned int tcr;

 	tcr = DAVINCI_TIMER_ENAMODE_ONESHOT <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
 	/* Same as above. */
 	tcr |= DAVINCI_TIMER_ENAMODE_PERIODIC <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;

 	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
 }

 static int davinci_clockevent_shutdown(struct clock_event_device *dev)
 {
 	struct davinci_clockevent *clockevent;

 	clockevent = to_davinci_clockevent(dev);

 	davinci_tim12_shutdown(clockevent->base);

 	return 0;
 }

 static int davinci_clockevent_set_oneshot(struct clock_event_device *dev)
 {
 	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);

 	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);

 	davinci_tim12_set_oneshot(clockevent->base);

 	return 0;
 }

 static int
 davinci_clockevent_set_next_event_std(unsigned long cycles,
 				      struct clock_event_device *dev)
 {
 	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);

 	davinci_clockevent_shutdown(dev);

 	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);
 	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_PRD12, cycles);

 	davinci_clockevent_set_oneshot(dev);

 	return 0;
 }

 static int
 davinci_clockevent_set_next_event_cmp(unsigned long cycles,
 				      struct clock_event_device *dev)
 {
 	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);
 	unsigned int curr_time;

 	curr_time = davinci_clockevent_read(clockevent,
 					    DAVINCI_TIMER_REG_TIM12);
 	davinci_clockevent_write(clockevent,
 				 clockevent->cmp_off, curr_time + cycles);

 	return 0;
 }

 static irqreturn_t davinci_timer_irq_timer(int irq, void *data)
 {
 	struct davinci_clockevent *clockevent = data;

 	if (!clockevent_state_oneshot(&clockevent->dev))
 		davinci_tim12_shutdown(clockevent->base);

 	clockevent->dev.event_handler(&clockevent->dev);

 	return IRQ_HANDLED;
 }

 static u64 notrace davinci_timer_read_sched_clock(void)
 {
 	return readl_relaxed(davinci_clocksource.base +
 			     davinci_clocksource.tim_off);
 }

 static u64 davinci_clocksource_read(struct clocksource *dev)
 {
 	return davinci_timer_read_sched_clock();
 }

 /*
  * Standard use-case: we're using tim12 for clockevent and tim34 for
  * clocksource. The default is making the former run in oneshot mode
  * and the latter in periodic mode.
  */
 static void davinci_clocksource_init_tim34(void __iomem *base)
 {
 	int tcr;

 	tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;
 	tcr |= DAVINCI_TIMER_ENAMODE_ONESHOT <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;

 	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
 	writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD34);
 	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
 }

 /*
  * Special use-case on da830: the DSP may use tim34. We're using tim12 for
  * both clocksource and clockevent. We set tim12 to periodic and don't touch
  * tim34.
  */
 static void davinci_clocksource_init_tim12(void __iomem *base)
 {
 	unsigned int tcr;

 	tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
 		DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;

 	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
 	writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD12);
 	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
 }

 static void davinci_timer_init(void __iomem *base)
 {
 	/* Set clock to internal mode and disable it. */
 	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TCR);
 	/*
 	 * Reset both 32-bit timers, set no prescaler for timer 34, set the
 	 * timer to dual 32-bit unchained mode, unreset both 32-bit timers.
 	 */
 	writel_relaxed(DAVINCI_TIMER_TGCR_DEFAULT,
 		       base + DAVINCI_TIMER_REG_TGCR);
 	/* Init both counters to zero. */
 	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
 	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
 }

 int __init davinci_timer_register(struct clk *clk,
 				  const struct davinci_timer_cfg *timer_cfg)
 {
 	struct davinci_clockevent *clockevent;
 	unsigned int tick_rate;
 	void __iomem *base;
 	int rv;

 	rv = clk_prepare_enable(clk);
 	if (rv) {
 		pr_err("Unable to prepare and enable the timer clock\n");
 		return rv;
 	}

 	if (!request_mem_region(timer_cfg->reg.start,
 				resource_size(&timer_cfg->reg),
 				"davinci-timer")) {
 		pr_err("Unable to request memory region\n");
 		rv = -EBUSY;
 		goto exit_clk_disable;
 	}

 	base = ioremap(timer_cfg->reg.start, resource_size(&timer_cfg->reg));
 	if (!base) {
 		pr_err("Unable to map the register range\n");
 		rv = -ENOMEM;
 		goto exit_mem_region;
 	}

 	davinci_timer_init(base);
 	tick_rate = clk_get_rate(clk);

 	clockevent = kzalloc(sizeof(*clockevent), GFP_KERNEL);
 	if (!clockevent) {
 		rv = -ENOMEM;
 		goto exit_iounmap_base;
 	}

 	clockevent->dev.name = "tim12";
 	clockevent->dev.features = CLOCK_EVT_FEAT_ONESHOT;
 	clockevent->dev.cpumask = cpumask_of(0);
 	clockevent->base = base;

 	if (timer_cfg->cmp_off) {
 		clockevent->cmp_off = timer_cfg->cmp_off;
 		clockevent->dev.set_next_event =
 				davinci_clockevent_set_next_event_cmp;
 	} else {
 		clockevent->dev.set_next_event =
 				davinci_clockevent_set_next_event_std;
 		clockevent->dev.set_state_oneshot =
 				davinci_clockevent_set_oneshot;
 		clockevent->dev.set_state_shutdown =
 				davinci_clockevent_shutdown;
 	}

 	rv = request_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
 			 davinci_timer_irq_timer, IRQF_TIMER,
 			 "clockevent/tim12", clockevent);
 	if (rv) {
 		pr_err("Unable to request the clockevent interrupt\n");
 		goto exit_free_clockevent;
 	}

 	davinci_clocksource.dev.rating = 300;
 	davinci_clocksource.dev.read = davinci_clocksource_read;
 	davinci_clocksource.dev.mask =
 			CLOCKSOURCE_MASK(DAVINCI_TIMER_CLKSRC_BITS);
 	davinci_clocksource.dev.flags = CLOCK_SOURCE_IS_CONTINUOUS;
 	davinci_clocksource.base = base;

 	if (timer_cfg->cmp_off) {
 		davinci_clocksource.dev.name = "tim12";
 		davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM12;
 		davinci_clocksource_init_tim12(base);
 	} else {
 		davinci_clocksource.dev.name = "tim34";
 		davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34;
 		davinci_clocksource_init_tim34(base);
 	}

 	clockevents_config_and_register(&clockevent->dev, tick_rate,
 					DAVINCI_TIMER_MIN_DELTA,
 					DAVINCI_TIMER_MAX_DELTA);

 	rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
 	if (rv) {
 		pr_err("Unable to register clocksource\n");
 		goto exit_free_irq;
 	}

 	sched_clock_register(davinci_timer_read_sched_clock,
 			     DAVINCI_TIMER_CLKSRC_BITS, tick_rate);

 	return 0;

 exit_free_irq:
 	free_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
 			clockevent);
 exit_free_clockevent:
 	kfree(clockevent);
 exit_iounmap_base:
 	iounmap(base);
 exit_mem_region:
 	release_mem_region(timer_cfg->reg.start,
 			   resource_size(&timer_cfg->reg));
 exit_clk_disable:
 	clk_disable_unprepare(clk);
 	return rv;
 }

 static int __init of_davinci_timer_register(struct device_node *np)
 {
 	struct davinci_timer_cfg timer_cfg = { };
 	struct clk *clk;
 	int rv;

 	rv = of_address_to_resource(np, 0, &timer_cfg.reg);
 	if (rv) {
 		pr_err("Unable to get the register range for timer\n");
 		return rv;
 	}

 	rv = of_irq_to_resource_table(np, timer_cfg.irq,
 				      DAVINCI_TIMER_NUM_IRQS);
 	if (rv != DAVINCI_TIMER_NUM_IRQS) {
 		pr_err("Unable to get the interrupts for timer\n");
 		return rv;
 	}

 	clk = of_clk_get(np, 0);
 	if (IS_ERR(clk)) {
 		pr_err("Unable to get the timer clock\n");
 		return PTR_ERR(clk);
 	}

 	rv = davinci_timer_register(clk, &timer_cfg);
 	if (rv)
 		clk_put(clk);

 	return rv;
 }
 TIMER_OF_DECLARE(davinci_timer, "ti,da830-timer", of_davinci_timer_register);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* TI DaVinci clocksource driver
	*
	* Copyright (C) 2019 Texas Instruments
	* Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
	* (with tiny parts adopted from code by Kevin Hilman <khilman@baylibre.com>)
	*/

	#include <linux/clk.h>
	#include <linux/clockchips.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/sched_clock.h>

	#include <clocksource/timer-davinci.h>

	#undef pr_fmt
	#define pr_fmt(fmt) "%s: " fmt, __func__

	#define DAVINCI_TIMER_REG_TIM12 0x10
	#define DAVINCI_TIMER_REG_TIM34 0x14
	#define DAVINCI_TIMER_REG_PRD12 0x18
	#define DAVINCI_TIMER_REG_PRD34 0x1c
	#define DAVINCI_TIMER_REG_TCR 0x20
	#define DAVINCI_TIMER_REG_TGCR 0x24

	#define DAVINCI_TIMER_TIMMODE_MASK GENMASK(3, 2)
	#define DAVINCI_TIMER_RESET_MASK GENMASK(1, 0)
	#define DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED BIT(2)
	#define DAVINCI_TIMER_UNRESET GENMASK(1, 0)

	#define DAVINCI_TIMER_ENAMODE_MASK GENMASK(1, 0)
	#define DAVINCI_TIMER_ENAMODE_DISABLED 0x00
	#define DAVINCI_TIMER_ENAMODE_ONESHOT BIT(0)
	#define DAVINCI_TIMER_ENAMODE_PERIODIC BIT(1)

	#define DAVINCI_TIMER_ENAMODE_SHIFT_TIM12 6
	#define DAVINCI_TIMER_ENAMODE_SHIFT_TIM34 22

	#define DAVINCI_TIMER_MIN_DELTA 0x01
	#define DAVINCI_TIMER_MAX_DELTA 0xfffffffe

	#define DAVINCI_TIMER_CLKSRC_BITS 32

	#define DAVINCI_TIMER_TGCR_DEFAULT \
	(DAVINCI_TIMER_TIMMODE_32BIT_UNCHAINED \| DAVINCI_TIMER_UNRESET)

	struct davinci_clockevent {
	struct clock_event_device dev;
	void __iomem *base;
	unsigned int cmp_off;
	};

	/*
	* This must be globally accessible by davinci_timer_read_sched_clock(), so
	* let's keep it here.
	*/
	static struct {
	struct clocksource dev;
	void __iomem *base;
	unsigned int tim_off;
	} davinci_clocksource;

	static struct davinci_clockevent *
	to_davinci_clockevent(struct clock_event_device *clockevent)
	{
	return container_of(clockevent, struct davinci_clockevent, dev);
	}

	static unsigned int
	davinci_clockevent_read(struct davinci_clockevent *clockevent,
	unsigned int reg)
	{
	return readl_relaxed(clockevent->base + reg);
	}

	static void davinci_clockevent_write(struct davinci_clockevent *clockevent,
	unsigned int reg, unsigned int val)
	{
	writel_relaxed(val, clockevent->base + reg);
	}

	static void davinci_tim12_shutdown(void __iomem *base)
	{
	unsigned int tcr;

	tcr = DAVINCI_TIMER_ENAMODE_DISABLED <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
	/*
	* This function is only ever called if we're using both timer
	* halves. In this case TIM34 runs in periodic mode and we must
	* not modify it.
	*/
	tcr \|= DAVINCI_TIMER_ENAMODE_PERIODIC <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;

	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
	}

	static void davinci_tim12_set_oneshot(void __iomem *base)
	{
	unsigned int tcr;

	tcr = DAVINCI_TIMER_ENAMODE_ONESHOT <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;
	/* Same as above. */
	tcr \|= DAVINCI_TIMER_ENAMODE_PERIODIC <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;

	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
	}

	static int davinci_clockevent_shutdown(struct clock_event_device *dev)
	{
	struct davinci_clockevent *clockevent;

	clockevent = to_davinci_clockevent(dev);

	davinci_tim12_shutdown(clockevent->base);

	return 0;
	}

	static int davinci_clockevent_set_oneshot(struct clock_event_device *dev)
	{
	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);

	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);

	davinci_tim12_set_oneshot(clockevent->base);

	return 0;
	}

	static int
	davinci_clockevent_set_next_event_std(unsigned long cycles,
	struct clock_event_device *dev)
	{
	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);

	davinci_clockevent_shutdown(dev);

	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_TIM12, 0x0);
	davinci_clockevent_write(clockevent, DAVINCI_TIMER_REG_PRD12, cycles);

	davinci_clockevent_set_oneshot(dev);

	return 0;
	}

	static int
	davinci_clockevent_set_next_event_cmp(unsigned long cycles,
	struct clock_event_device *dev)
	{
	struct davinci_clockevent *clockevent = to_davinci_clockevent(dev);
	unsigned int curr_time;

	curr_time = davinci_clockevent_read(clockevent,
	DAVINCI_TIMER_REG_TIM12);
	davinci_clockevent_write(clockevent,
	clockevent->cmp_off, curr_time + cycles);

	return 0;
	}

	static irqreturn_t davinci_timer_irq_timer(int irq, void *data)
	{
	struct davinci_clockevent *clockevent = data;

	if (!clockevent_state_oneshot(&clockevent->dev))
	davinci_tim12_shutdown(clockevent->base);

	clockevent->dev.event_handler(&clockevent->dev);

	return IRQ_HANDLED;
	}

	static u64 notrace davinci_timer_read_sched_clock(void)
	{
	return readl_relaxed(davinci_clocksource.base +
	davinci_clocksource.tim_off);
	}

	static u64 davinci_clocksource_read(struct clocksource *dev)
	{
	return davinci_timer_read_sched_clock();
	}

	/*
	* Standard use-case: we're using tim12 for clockevent and tim34 for
	* clocksource. The default is making the former run in oneshot mode
	* and the latter in periodic mode.
	*/
	static void davinci_clocksource_init_tim34(void __iomem *base)
	{
	int tcr;

	tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM34;
	tcr \|= DAVINCI_TIMER_ENAMODE_ONESHOT <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;

	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
	writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD34);
	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
	}

	/*
	* Special use-case on da830: the DSP may use tim34. We're using tim12 for
	* both clocksource and clockevent. We set tim12 to periodic and don't touch
	* tim34.
	*/
	static void davinci_clocksource_init_tim12(void __iomem *base)
	{
	unsigned int tcr;

	tcr = DAVINCI_TIMER_ENAMODE_PERIODIC <<
	DAVINCI_TIMER_ENAMODE_SHIFT_TIM12;

	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
	writel_relaxed(UINT_MAX, base + DAVINCI_TIMER_REG_PRD12);
	writel_relaxed(tcr, base + DAVINCI_TIMER_REG_TCR);
	}

	static void davinci_timer_init(void __iomem *base)
	{
	/* Set clock to internal mode and disable it. */
	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TCR);
	/*
	* Reset both 32-bit timers, set no prescaler for timer 34, set the
	* timer to dual 32-bit unchained mode, unreset both 32-bit timers.
	*/
	writel_relaxed(DAVINCI_TIMER_TGCR_DEFAULT,
	base + DAVINCI_TIMER_REG_TGCR);
	/* Init both counters to zero. */
	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM12);
	writel_relaxed(0x0, base + DAVINCI_TIMER_REG_TIM34);
	}

	int __init davinci_timer_register(struct clk *clk,
	const struct davinci_timer_cfg *timer_cfg)
	{
	struct davinci_clockevent *clockevent;
	unsigned int tick_rate;
	void __iomem *base;
	int rv;

	rv = clk_prepare_enable(clk);
	if (rv) {
	pr_err("Unable to prepare and enable the timer clock\n");
	return rv;
	}

	if (!request_mem_region(timer_cfg->reg.start,
	resource_size(&timer_cfg->reg),
	"davinci-timer")) {
	pr_err("Unable to request memory region\n");
	rv = -EBUSY;
	goto exit_clk_disable;
	}

	base = ioremap(timer_cfg->reg.start, resource_size(&timer_cfg->reg));
	if (!base) {
	pr_err("Unable to map the register range\n");
	rv = -ENOMEM;
	goto exit_mem_region;
	}

	davinci_timer_init(base);
	tick_rate = clk_get_rate(clk);

	clockevent = kzalloc(sizeof(*clockevent), GFP_KERNEL);
	if (!clockevent) {
	rv = -ENOMEM;
	goto exit_iounmap_base;
	}

	clockevent->dev.name = "tim12";
	clockevent->dev.features = CLOCK_EVT_FEAT_ONESHOT;
	clockevent->dev.cpumask = cpumask_of(0);
	clockevent->base = base;

	if (timer_cfg->cmp_off) {
	clockevent->cmp_off = timer_cfg->cmp_off;
	clockevent->dev.set_next_event =
	davinci_clockevent_set_next_event_cmp;
	} else {
	clockevent->dev.set_next_event =
	davinci_clockevent_set_next_event_std;
	clockevent->dev.set_state_oneshot =
	davinci_clockevent_set_oneshot;
	clockevent->dev.set_state_shutdown =
	davinci_clockevent_shutdown;
	}

	rv = request_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
	davinci_timer_irq_timer, IRQF_TIMER,
	"clockevent/tim12", clockevent);
	if (rv) {
	pr_err("Unable to request the clockevent interrupt\n");
	goto exit_free_clockevent;
	}

	davinci_clocksource.dev.rating = 300;
	davinci_clocksource.dev.read = davinci_clocksource_read;
	davinci_clocksource.dev.mask =
	CLOCKSOURCE_MASK(DAVINCI_TIMER_CLKSRC_BITS);
	davinci_clocksource.dev.flags = CLOCK_SOURCE_IS_CONTINUOUS;
	davinci_clocksource.base = base;

	if (timer_cfg->cmp_off) {
	davinci_clocksource.dev.name = "tim12";
	davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM12;
	davinci_clocksource_init_tim12(base);
	} else {
	davinci_clocksource.dev.name = "tim34";
	davinci_clocksource.tim_off = DAVINCI_TIMER_REG_TIM34;
	davinci_clocksource_init_tim34(base);
	}

	clockevents_config_and_register(&clockevent->dev, tick_rate,
	DAVINCI_TIMER_MIN_DELTA,
	DAVINCI_TIMER_MAX_DELTA);

	rv = clocksource_register_hz(&davinci_clocksource.dev, tick_rate);
	if (rv) {
	pr_err("Unable to register clocksource\n");
	goto exit_free_irq;
	}

	sched_clock_register(davinci_timer_read_sched_clock,
	DAVINCI_TIMER_CLKSRC_BITS, tick_rate);

	return 0;

	exit_free_irq:
	free_irq(timer_cfg->irq[DAVINCI_TIMER_CLOCKEVENT_IRQ].start,
	clockevent);
	exit_free_clockevent:
	kfree(clockevent);
	exit_iounmap_base:
	iounmap(base);
	exit_mem_region:
	release_mem_region(timer_cfg->reg.start,
	resource_size(&timer_cfg->reg));
	exit_clk_disable:
	clk_disable_unprepare(clk);
	return rv;
	}

	static int __init of_davinci_timer_register(struct device_node *np)
	{
	struct davinci_timer_cfg timer_cfg = { };
	struct clk *clk;
	int rv;

	rv = of_address_to_resource(np, 0, &timer_cfg.reg);
	if (rv) {
	pr_err("Unable to get the register range for timer\n");
	return rv;
	}

	rv = of_irq_to_resource_table(np, timer_cfg.irq,
	DAVINCI_TIMER_NUM_IRQS);
	if (rv != DAVINCI_TIMER_NUM_IRQS) {
	pr_err("Unable to get the interrupts for timer\n");
	return rv;
	}

	clk = of_clk_get(np, 0);
	if (IS_ERR(clk)) {
	pr_err("Unable to get the timer clock\n");
	return PTR_ERR(clk);
	}

	rv = davinci_timer_register(clk, &timer_cfg);
	if (rv)
	clk_put(clk);

	return rv;
	}
	TIMER_OF_DECLARE(davinci_timer, "ti,da830-timer", of_davinci_timer_register);