drivers/clocksource/sh_tmu.c - fp2-dev/kernel/msm - Gitiles

 /*
  * SuperH Timer Support - TMU
  *
  *  Copyright (C) 2009 Magnus Damm
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */

 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/irq.h>
 #include <linux/err.h>
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/sh_timer.h>
 #include <linux/slab.h>

 struct sh_tmu_priv {
 	void __iomem *mapbase;
 	struct clk *clk;
 	struct irqaction irqaction;
 	struct platform_device *pdev;
 	unsigned long rate;
 	unsigned long periodic;
 	struct clock_event_device ced;
 	struct clocksource cs;
 };

 static DEFINE_SPINLOCK(sh_tmu_lock);

 #define TSTR -1 /* shared register */
 #define TCOR  0 /* channel register */
 #define TCNT 1 /* channel register */
 #define TCR 2 /* channel register */

 static inline unsigned long sh_tmu_read(struct sh_tmu_priv *p, int reg_nr)
 {
 	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
 	void __iomem *base = p->mapbase;
 	unsigned long offs;

 	if (reg_nr == TSTR)
 		return ioread8(base - cfg->channel_offset);

 	offs = reg_nr << 2;

 	if (reg_nr == TCR)
 		return ioread16(base + offs);
 	else
 		return ioread32(base + offs);
 }

 static inline void sh_tmu_write(struct sh_tmu_priv *p, int reg_nr,
 				unsigned long value)
 {
 	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
 	void __iomem *base = p->mapbase;
 	unsigned long offs;

 	if (reg_nr == TSTR) {
 		iowrite8(value, base - cfg->channel_offset);
 		return;
 	}

 	offs = reg_nr << 2;

 	if (reg_nr == TCR)
 		iowrite16(value, base + offs);
 	else
 		iowrite32(value, base + offs);
 }

 static void sh_tmu_start_stop_ch(struct sh_tmu_priv *p, int start)
 {
 	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
 	unsigned long flags, value;

 	/* start stop register shared by multiple timer channels */
 	spin_lock_irqsave(&sh_tmu_lock, flags);
 	value = sh_tmu_read(p, TSTR);

 	if (start)
 		value |= 1 << cfg->timer_bit;
 	else
 		value &= ~(1 << cfg->timer_bit);

 	sh_tmu_write(p, TSTR, value);
 	spin_unlock_irqrestore(&sh_tmu_lock, flags);
 }

 static int sh_tmu_enable(struct sh_tmu_priv *p)
 {
 	int ret;

 	/* wake up device and enable clock */
 	pm_runtime_get_sync(&p->pdev->dev);
 	ret = clk_enable(p->clk);
 	if (ret) {
 		dev_err(&p->pdev->dev, "cannot enable clock\n");
 		pm_runtime_put_sync(&p->pdev->dev);
 		return ret;
 	}

 	/* make sure channel is disabled */
 	sh_tmu_start_stop_ch(p, 0);

 	/* maximum timeout */
 	sh_tmu_write(p, TCOR, 0xffffffff);
 	sh_tmu_write(p, TCNT, 0xffffffff);

 	/* configure channel to parent clock / 4, irq off */
 	p->rate = clk_get_rate(p->clk) / 4;
 	sh_tmu_write(p, TCR, 0x0000);

 	/* enable channel */
 	sh_tmu_start_stop_ch(p, 1);

 	return 0;
 }

 static void sh_tmu_disable(struct sh_tmu_priv *p)
 {
 	/* disable channel */
 	sh_tmu_start_stop_ch(p, 0);

 	/* disable interrupts in TMU block */
 	sh_tmu_write(p, TCR, 0x0000);

 	/* stop clock and mark device as idle */
 	clk_disable(p->clk);
 	pm_runtime_put_sync(&p->pdev->dev);
 }

 static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta,
 			    int periodic)
 {
 	/* stop timer */
 	sh_tmu_start_stop_ch(p, 0);

 	/* acknowledge interrupt */
 	sh_tmu_read(p, TCR);

 	/* enable interrupt */
 	sh_tmu_write(p, TCR, 0x0020);

 	/* reload delta value in case of periodic timer */
 	if (periodic)
 		sh_tmu_write(p, TCOR, delta);
 	else
 		sh_tmu_write(p, TCOR, 0xffffffff);

 	sh_tmu_write(p, TCNT, delta);

 	/* start timer */
 	sh_tmu_start_stop_ch(p, 1);
 }

 static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
 {
 	struct sh_tmu_priv *p = dev_id;

 	/* disable or acknowledge interrupt */
 	if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT)
 		sh_tmu_write(p, TCR, 0x0000);
 	else
 		sh_tmu_write(p, TCR, 0x0020);

 	/* notify clockevent layer */
 	p->ced.event_handler(&p->ced);
 	return IRQ_HANDLED;
 }

 static struct sh_tmu_priv *cs_to_sh_tmu(struct clocksource *cs)
 {
 	return container_of(cs, struct sh_tmu_priv, cs);
 }

 static cycle_t sh_tmu_clocksource_read(struct clocksource *cs)
 {
 	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);

 	return sh_tmu_read(p, TCNT) ^ 0xffffffff;
 }

 static int sh_tmu_clocksource_enable(struct clocksource *cs)
 {
 	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
 	int ret;

 	ret = sh_tmu_enable(p);
 	if (!ret)
 		__clocksource_updatefreq_hz(cs, p->rate);
 	return ret;
 }

 static void sh_tmu_clocksource_disable(struct clocksource *cs)
 {
 	sh_tmu_disable(cs_to_sh_tmu(cs));
 }

 static int sh_tmu_register_clocksource(struct sh_tmu_priv *p,
 				       char *name, unsigned long rating)
 {
 	struct clocksource *cs = &p->cs;

 	cs->name = name;
 	cs->rating = rating;
 	cs->read = sh_tmu_clocksource_read;
 	cs->enable = sh_tmu_clocksource_enable;
 	cs->disable = sh_tmu_clocksource_disable;
 	cs->mask = CLOCKSOURCE_MASK(32);
 	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;

 	dev_info(&p->pdev->dev, "used as clock source\n");

 	/* Register with dummy 1 Hz value, gets updated in ->enable() */
 	clocksource_register_hz(cs, 1);
 	return 0;
 }

 static struct sh_tmu_priv *ced_to_sh_tmu(struct clock_event_device *ced)
 {
 	return container_of(ced, struct sh_tmu_priv, ced);
 }

 static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic)
 {
 	struct clock_event_device *ced = &p->ced;

 	sh_tmu_enable(p);

 	/* TODO: calculate good shift from rate and counter bit width */

 	ced->shift = 32;
 	ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
 	ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced);
 	ced->min_delta_ns = 5000;

 	if (periodic) {
 		p->periodic = (p->rate + HZ/2) / HZ;
 		sh_tmu_set_next(p, p->periodic, 1);
 	}
 }

 static void sh_tmu_clock_event_mode(enum clock_event_mode mode,
 				    struct clock_event_device *ced)
 {
 	struct sh_tmu_priv *p = ced_to_sh_tmu(ced);
 	int disabled = 0;

 	/* deal with old setting first */
 	switch (ced->mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
 	case CLOCK_EVT_MODE_ONESHOT:
 		sh_tmu_disable(p);
 		disabled = 1;
 		break;
 	default:
 		break;
 	}

 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
 		dev_info(&p->pdev->dev, "used for periodic clock events\n");
 		sh_tmu_clock_event_start(p, 1);
 		break;
 	case CLOCK_EVT_MODE_ONESHOT:
 		dev_info(&p->pdev->dev, "used for oneshot clock events\n");
 		sh_tmu_clock_event_start(p, 0);
 		break;
 	case CLOCK_EVT_MODE_UNUSED:
 		if (!disabled)
 			sh_tmu_disable(p);
 		break;
 	case CLOCK_EVT_MODE_SHUTDOWN:
 	default:
 		break;
 	}
 }

 static int sh_tmu_clock_event_next(unsigned long delta,
 				   struct clock_event_device *ced)
 {
 	struct sh_tmu_priv *p = ced_to_sh_tmu(ced);

 	BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);

 	/* program new delta value */
 	sh_tmu_set_next(p, delta, 0);
 	return 0;
 }

 static void sh_tmu_register_clockevent(struct sh_tmu_priv *p,
 				       char *name, unsigned long rating)
 {
 	struct clock_event_device *ced = &p->ced;
 	int ret;

 	memset(ced, 0, sizeof(*ced));

 	ced->name = name;
 	ced->features = CLOCK_EVT_FEAT_PERIODIC;
 	ced->features |= CLOCK_EVT_FEAT_ONESHOT;
 	ced->rating = rating;
 	ced->cpumask = cpumask_of(0);
 	ced->set_next_event = sh_tmu_clock_event_next;
 	ced->set_mode = sh_tmu_clock_event_mode;

 	dev_info(&p->pdev->dev, "used for clock events\n");
 	clockevents_register_device(ced);

 	ret = setup_irq(p->irqaction.irq, &p->irqaction);
 	if (ret) {
 		dev_err(&p->pdev->dev, "failed to request irq %d\n",
 			p->irqaction.irq);
 		return;
 	}
 }

 static int sh_tmu_register(struct sh_tmu_priv *p, char *name,
 		    unsigned long clockevent_rating,
 		    unsigned long clocksource_rating)
 {
 	if (clockevent_rating)
 		sh_tmu_register_clockevent(p, name, clockevent_rating);
 	else if (clocksource_rating)
 		sh_tmu_register_clocksource(p, name, clocksource_rating);

 	return 0;
 }

 static int sh_tmu_setup(struct sh_tmu_priv *p, struct platform_device *pdev)
 {
 	struct sh_timer_config *cfg = pdev->dev.platform_data;
 	struct resource *res;
 	int irq, ret;
 	ret = -ENXIO;

 	memset(p, 0, sizeof(*p));
 	p->pdev = pdev;

 	if (!cfg) {
 		dev_err(&p->pdev->dev, "missing platform data\n");
 		goto err0;
 	}

 	platform_set_drvdata(pdev, p);

 	res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&p->pdev->dev, "failed to get I/O memory\n");
 		goto err0;
 	}

 	irq = platform_get_irq(p->pdev, 0);
 	if (irq < 0) {
 		dev_err(&p->pdev->dev, "failed to get irq\n");
 		goto err0;
 	}

 	/* map memory, let mapbase point to our channel */
 	p->mapbase = ioremap_nocache(res->start, resource_size(res));
 	if (p->mapbase == NULL) {
 		dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
 		goto err0;
 	}

 	/* setup data for setup_irq() (too early for request_irq()) */
 	p->irqaction.name = dev_name(&p->pdev->dev);
 	p->irqaction.handler = sh_tmu_interrupt;
 	p->irqaction.dev_id = p;
 	p->irqaction.irq = irq;
 	p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | \
 			     IRQF_IRQPOLL  | IRQF_NOBALANCING;

 	/* get hold of clock */
 	p->clk = clk_get(&p->pdev->dev, "tmu_fck");
 	if (IS_ERR(p->clk)) {
 		dev_err(&p->pdev->dev, "cannot get clock\n");
 		ret = PTR_ERR(p->clk);
 		goto err1;
 	}

 	return sh_tmu_register(p, (char *)dev_name(&p->pdev->dev),
 			       cfg->clockevent_rating,
 			       cfg->clocksource_rating);
  err1:
 	iounmap(p->mapbase);
  err0:
 	return ret;
 }

 static int __devinit sh_tmu_probe(struct platform_device *pdev)
 {
 	struct sh_tmu_priv *p = platform_get_drvdata(pdev);
 	int ret;

 	if (p) {
 		dev_info(&pdev->dev, "kept as earlytimer\n");
 		pm_runtime_enable(&pdev->dev);
 		return 0;
 	}

 	p = kmalloc(sizeof(*p), GFP_KERNEL);
 	if (p == NULL) {
 		dev_err(&pdev->dev, "failed to allocate driver data\n");
 		return -ENOMEM;
 	}

 	ret = sh_tmu_setup(p, pdev);
 	if (ret) {
 		kfree(p);
 		platform_set_drvdata(pdev, NULL);
 	}

 	if (!is_early_platform_device(pdev))
 		pm_runtime_enable(&pdev->dev);
 	return ret;
 }

 static int __devexit sh_tmu_remove(struct platform_device *pdev)
 {
 	return -EBUSY; /* cannot unregister clockevent and clocksource */
 }

 static struct platform_driver sh_tmu_device_driver = {
 	.probe		= sh_tmu_probe,
 	.remove		= __devexit_p(sh_tmu_remove),
 	.driver		= {
 		.name	= "sh_tmu",
 	}
 };

 static int __init sh_tmu_init(void)
 {
 	return platform_driver_register(&sh_tmu_device_driver);
 }

 static void __exit sh_tmu_exit(void)
 {
 	platform_driver_unregister(&sh_tmu_device_driver);
 }

 early_platform_init("earlytimer", &sh_tmu_device_driver);
 module_init(sh_tmu_init);
 module_exit(sh_tmu_exit);

 MODULE_AUTHOR("Magnus Damm");
 MODULE_DESCRIPTION("SuperH TMU Timer Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* SuperH Timer Support - TMU
	*
	* Copyright (C) 2009 Magnus Damm
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/clk.h>
	#include <linux/pm_runtime.h>
	#include <linux/irq.h>
	#include <linux/err.h>
	#include <linux/clocksource.h>
	#include <linux/clockchips.h>
	#include <linux/sh_timer.h>
	#include <linux/slab.h>

	struct sh_tmu_priv {
	void __iomem *mapbase;
	struct clk *clk;
	struct irqaction irqaction;
	struct platform_device *pdev;
	unsigned long rate;
	unsigned long periodic;
	struct clock_event_device ced;
	struct clocksource cs;
	};

	static DEFINE_SPINLOCK(sh_tmu_lock);

	#define TSTR -1 /* shared register */
	#define TCOR 0 /* channel register */
	#define TCNT 1 /* channel register */
	#define TCR 2 /* channel register */

	static inline unsigned long sh_tmu_read(struct sh_tmu_priv *p, int reg_nr)
	{
	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
	void __iomem *base = p->mapbase;
	unsigned long offs;

	if (reg_nr == TSTR)
	return ioread8(base - cfg->channel_offset);

	offs = reg_nr << 2;

	if (reg_nr == TCR)
	return ioread16(base + offs);
	else
	return ioread32(base + offs);
	}

	static inline void sh_tmu_write(struct sh_tmu_priv *p, int reg_nr,
	unsigned long value)
	{
	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
	void __iomem *base = p->mapbase;
	unsigned long offs;

	if (reg_nr == TSTR) {
	iowrite8(value, base - cfg->channel_offset);
	return;
	}

	offs = reg_nr << 2;

	if (reg_nr == TCR)
	iowrite16(value, base + offs);
	else
	iowrite32(value, base + offs);
	}

	static void sh_tmu_start_stop_ch(struct sh_tmu_priv *p, int start)
	{
	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
	unsigned long flags, value;

	/* start stop register shared by multiple timer channels */
	spin_lock_irqsave(&sh_tmu_lock, flags);
	value = sh_tmu_read(p, TSTR);

	if (start)
	value \|= 1 << cfg->timer_bit;
	else
	value &= ~(1 << cfg->timer_bit);

	sh_tmu_write(p, TSTR, value);
	spin_unlock_irqrestore(&sh_tmu_lock, flags);
	}

	static int sh_tmu_enable(struct sh_tmu_priv *p)
	{
	int ret;

	/* wake up device and enable clock */
	pm_runtime_get_sync(&p->pdev->dev);
	ret = clk_enable(p->clk);
	if (ret) {
	dev_err(&p->pdev->dev, "cannot enable clock\n");
	pm_runtime_put_sync(&p->pdev->dev);
	return ret;
	}

	/* make sure channel is disabled */
	sh_tmu_start_stop_ch(p, 0);

	/* maximum timeout */
	sh_tmu_write(p, TCOR, 0xffffffff);
	sh_tmu_write(p, TCNT, 0xffffffff);

	/* configure channel to parent clock / 4, irq off */
	p->rate = clk_get_rate(p->clk) / 4;
	sh_tmu_write(p, TCR, 0x0000);

	/* enable channel */
	sh_tmu_start_stop_ch(p, 1);

	return 0;
	}

	static void sh_tmu_disable(struct sh_tmu_priv *p)
	{
	/* disable channel */
	sh_tmu_start_stop_ch(p, 0);

	/* disable interrupts in TMU block */
	sh_tmu_write(p, TCR, 0x0000);

	/* stop clock and mark device as idle */
	clk_disable(p->clk);
	pm_runtime_put_sync(&p->pdev->dev);
	}

	static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta,
	int periodic)
	{
	/* stop timer */
	sh_tmu_start_stop_ch(p, 0);

	/* acknowledge interrupt */
	sh_tmu_read(p, TCR);

	/* enable interrupt */
	sh_tmu_write(p, TCR, 0x0020);

	/* reload delta value in case of periodic timer */
	if (periodic)
	sh_tmu_write(p, TCOR, delta);
	else
	sh_tmu_write(p, TCOR, 0xffffffff);

	sh_tmu_write(p, TCNT, delta);

	/* start timer */
	sh_tmu_start_stop_ch(p, 1);
	}

	static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id)
	{
	struct sh_tmu_priv *p = dev_id;

	/* disable or acknowledge interrupt */
	if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT)
	sh_tmu_write(p, TCR, 0x0000);
	else
	sh_tmu_write(p, TCR, 0x0020);

	/* notify clockevent layer */
	p->ced.event_handler(&p->ced);
	return IRQ_HANDLED;
	}

	static struct sh_tmu_priv cs_to_sh_tmu(struct clocksource cs)
	{
	return container_of(cs, struct sh_tmu_priv, cs);
	}

	static cycle_t sh_tmu_clocksource_read(struct clocksource *cs)
	{
	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);

	return sh_tmu_read(p, TCNT) ^ 0xffffffff;
	}

	static int sh_tmu_clocksource_enable(struct clocksource *cs)
	{
	struct sh_tmu_priv *p = cs_to_sh_tmu(cs);
	int ret;

	ret = sh_tmu_enable(p);
	if (!ret)
	__clocksource_updatefreq_hz(cs, p->rate);
	return ret;
	}

	static void sh_tmu_clocksource_disable(struct clocksource *cs)
	{
	sh_tmu_disable(cs_to_sh_tmu(cs));
	}

	static int sh_tmu_register_clocksource(struct sh_tmu_priv *p,
	char *name, unsigned long rating)
	{
	struct clocksource *cs = &p->cs;

	cs->name = name;
	cs->rating = rating;
	cs->read = sh_tmu_clocksource_read;
	cs->enable = sh_tmu_clocksource_enable;
	cs->disable = sh_tmu_clocksource_disable;
	cs->mask = CLOCKSOURCE_MASK(32);
	cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;

	dev_info(&p->pdev->dev, "used as clock source\n");

	/* Register with dummy 1 Hz value, gets updated in ->enable() */
	clocksource_register_hz(cs, 1);
	return 0;
	}

	static struct sh_tmu_priv ced_to_sh_tmu(struct clock_event_device ced)
	{
	return container_of(ced, struct sh_tmu_priv, ced);
	}

	static void sh_tmu_clock_event_start(struct sh_tmu_priv *p, int periodic)
	{
	struct clock_event_device *ced = &p->ced;

	sh_tmu_enable(p);

	/* TODO: calculate good shift from rate and counter bit width */

	ced->shift = 32;
	ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
	ced->max_delta_ns = clockevent_delta2ns(0xffffffff, ced);
	ced->min_delta_ns = 5000;

	if (periodic) {
	p->periodic = (p->rate + HZ/2) / HZ;
	sh_tmu_set_next(p, p->periodic, 1);
	}
	}

	static void sh_tmu_clock_event_mode(enum clock_event_mode mode,
	struct clock_event_device *ced)
	{
	struct sh_tmu_priv *p = ced_to_sh_tmu(ced);
	int disabled = 0;

	/* deal with old setting first */
	switch (ced->mode) {
	case CLOCK_EVT_MODE_PERIODIC:
	case CLOCK_EVT_MODE_ONESHOT:
	sh_tmu_disable(p);
	disabled = 1;
	break;
	default:
	break;
	}

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
	dev_info(&p->pdev->dev, "used for periodic clock events\n");
	sh_tmu_clock_event_start(p, 1);
	break;
	case CLOCK_EVT_MODE_ONESHOT:
	dev_info(&p->pdev->dev, "used for oneshot clock events\n");
	sh_tmu_clock_event_start(p, 0);
	break;
	case CLOCK_EVT_MODE_UNUSED:
	if (!disabled)
	sh_tmu_disable(p);
	break;
	case CLOCK_EVT_MODE_SHUTDOWN:
	default:
	break;
	}
	}

	static int sh_tmu_clock_event_next(unsigned long delta,
	struct clock_event_device *ced)
	{
	struct sh_tmu_priv *p = ced_to_sh_tmu(ced);

	BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT);

	/* program new delta value */
	sh_tmu_set_next(p, delta, 0);
	return 0;
	}

	static void sh_tmu_register_clockevent(struct sh_tmu_priv *p,
	char *name, unsigned long rating)
	{
	struct clock_event_device *ced = &p->ced;
	int ret;

	memset(ced, 0, sizeof(*ced));

	ced->name = name;
	ced->features = CLOCK_EVT_FEAT_PERIODIC;
	ced->features \|= CLOCK_EVT_FEAT_ONESHOT;
	ced->rating = rating;
	ced->cpumask = cpumask_of(0);
	ced->set_next_event = sh_tmu_clock_event_next;
	ced->set_mode = sh_tmu_clock_event_mode;

	dev_info(&p->pdev->dev, "used for clock events\n");
	clockevents_register_device(ced);

	ret = setup_irq(p->irqaction.irq, &p->irqaction);
	if (ret) {
	dev_err(&p->pdev->dev, "failed to request irq %d\n",
	p->irqaction.irq);
	return;
	}
	}

	static int sh_tmu_register(struct sh_tmu_priv p, char name,
	unsigned long clockevent_rating,
	unsigned long clocksource_rating)
	{
	if (clockevent_rating)
	sh_tmu_register_clockevent(p, name, clockevent_rating);
	else if (clocksource_rating)
	sh_tmu_register_clocksource(p, name, clocksource_rating);

	return 0;
	}

	static int sh_tmu_setup(struct sh_tmu_priv p, struct platform_device pdev)
	{
	struct sh_timer_config *cfg = pdev->dev.platform_data;
	struct resource *res;
	int irq, ret;
	ret = -ENXIO;

	memset(p, 0, sizeof(*p));
	p->pdev = pdev;

	if (!cfg) {
	dev_err(&p->pdev->dev, "missing platform data\n");
	goto err0;
	}

	platform_set_drvdata(pdev, p);

	res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(&p->pdev->dev, "failed to get I/O memory\n");
	goto err0;
	}

	irq = platform_get_irq(p->pdev, 0);
	if (irq < 0) {
	dev_err(&p->pdev->dev, "failed to get irq\n");
	goto err0;
	}

	/* map memory, let mapbase point to our channel */
	p->mapbase = ioremap_nocache(res->start, resource_size(res));
	if (p->mapbase == NULL) {
	dev_err(&p->pdev->dev, "failed to remap I/O memory\n");
	goto err0;
	}

	/* setup data for setup_irq() (too early for request_irq()) */
	p->irqaction.name = dev_name(&p->pdev->dev);
	p->irqaction.handler = sh_tmu_interrupt;
	p->irqaction.dev_id = p;
	p->irqaction.irq = irq;
	p->irqaction.flags = IRQF_DISABLED \| IRQF_TIMER \| \
	IRQF_IRQPOLL \| IRQF_NOBALANCING;

	/* get hold of clock */
	p->clk = clk_get(&p->pdev->dev, "tmu_fck");
	if (IS_ERR(p->clk)) {
	dev_err(&p->pdev->dev, "cannot get clock\n");
	ret = PTR_ERR(p->clk);
	goto err1;
	}

	return sh_tmu_register(p, (char *)dev_name(&p->pdev->dev),
	cfg->clockevent_rating,
	cfg->clocksource_rating);
	err1:
	iounmap(p->mapbase);
	err0:
	return ret;
	}

	static int __devinit sh_tmu_probe(struct platform_device *pdev)
	{
	struct sh_tmu_priv *p = platform_get_drvdata(pdev);
	int ret;

	if (p) {
	dev_info(&pdev->dev, "kept as earlytimer\n");
	pm_runtime_enable(&pdev->dev);
	return 0;
	}

	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (p == NULL) {
	dev_err(&pdev->dev, "failed to allocate driver data\n");
	return -ENOMEM;
	}

	ret = sh_tmu_setup(p, pdev);
	if (ret) {
	kfree(p);
	platform_set_drvdata(pdev, NULL);
	}

	if (!is_early_platform_device(pdev))
	pm_runtime_enable(&pdev->dev);
	return ret;
	}

	static int __devexit sh_tmu_remove(struct platform_device *pdev)
	{
	return -EBUSY; /* cannot unregister clockevent and clocksource */
	}

	static struct platform_driver sh_tmu_device_driver = {
	.probe = sh_tmu_probe,
	.remove = __devexit_p(sh_tmu_remove),
	.driver = {
	.name = "sh_tmu",
	}
	};

	static int __init sh_tmu_init(void)
	{
	return platform_driver_register(&sh_tmu_device_driver);
	}

	static void __exit sh_tmu_exit(void)
	{
	platform_driver_unregister(&sh_tmu_device_driver);
	}

	early_platform_init("earlytimer", &sh_tmu_device_driver);
	module_init(sh_tmu_init);
	module_exit(sh_tmu_exit);

	MODULE_AUTHOR("Magnus Damm");
	MODULE_DESCRIPTION("SuperH TMU Timer Driver");
	MODULE_LICENSE("GPL v2");