drivers/clocksource/sh_mtu2.c - kernel/msm - Gitiles

 /*
  * SuperH Timer Support - MTU2
  *
  *  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/irq.h>
 #include <linux/err.h>
 #include <linux/clockchips.h>
 #include <linux/sh_timer.h>
 #include <linux/slab.h>

 struct sh_mtu2_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;
 };

 static DEFINE_SPINLOCK(sh_mtu2_lock);

 #define TSTR -1 /* shared register */
 #define TCR  0 /* channel register */
 #define TMDR 1 /* channel register */
 #define TIOR 2 /* channel register */
 #define TIER 3 /* channel register */
 #define TSR  4 /* channel register */
 #define TCNT 5 /* channel register */
 #define TGR  6 /* channel register */

 static unsigned long mtu2_reg_offs[] = {
 	[TCR] = 0,
 	[TMDR] = 1,
 	[TIOR] = 2,
 	[TIER] = 4,
 	[TSR] = 5,
 	[TCNT] = 6,
 	[TGR] = 8,
 };

 static inline unsigned long sh_mtu2_read(struct sh_mtu2_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 = mtu2_reg_offs[reg_nr];

 	if ((reg_nr == TCNT) || (reg_nr == TGR))
 		return ioread16(base + offs);
 	else
 		return ioread8(base + offs);
 }

 static inline void sh_mtu2_write(struct sh_mtu2_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 = mtu2_reg_offs[reg_nr];

 	if ((reg_nr == TCNT) || (reg_nr == TGR))
 		iowrite16(value, base + offs);
 	else
 		iowrite8(value, base + offs);
 }

 static void sh_mtu2_start_stop_ch(struct sh_mtu2_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_mtu2_lock, flags);
 	value = sh_mtu2_read(p, TSTR);

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

 	sh_mtu2_write(p, TSTR, value);
 	spin_unlock_irqrestore(&sh_mtu2_lock, flags);
 }

 static int sh_mtu2_enable(struct sh_mtu2_priv *p)
 {
 	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
 	int ret;

 	/* enable clock */
 	ret = clk_enable(p->clk);
 	if (ret) {
 		pr_err("sh_mtu2: cannot enable clock \"%s\"\n", cfg->clk);
 		return ret;
 	}

 	/* make sure channel is disabled */
 	sh_mtu2_start_stop_ch(p, 0);

 	p->rate = clk_get_rate(p->clk) / 64;
 	p->periodic = (p->rate + HZ/2) / HZ;

 	/* "Periodic Counter Operation" */
 	sh_mtu2_write(p, TCR, 0x23); /* TGRA clear, divide clock by 64 */
 	sh_mtu2_write(p, TIOR, 0);
 	sh_mtu2_write(p, TGR, p->periodic);
 	sh_mtu2_write(p, TCNT, 0);
 	sh_mtu2_write(p, TMDR, 0);
 	sh_mtu2_write(p, TIER, 0x01);

 	/* enable channel */
 	sh_mtu2_start_stop_ch(p, 1);

 	return 0;
 }

 static void sh_mtu2_disable(struct sh_mtu2_priv *p)
 {
 	/* disable channel */
 	sh_mtu2_start_stop_ch(p, 0);

 	/* stop clock */
 	clk_disable(p->clk);
 }

 static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
 {
 	struct sh_mtu2_priv *p = dev_id;

 	/* acknowledge interrupt */
 	sh_mtu2_read(p, TSR);
 	sh_mtu2_write(p, TSR, 0xfe);

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

 static struct sh_mtu2_priv *ced_to_sh_mtu2(struct clock_event_device *ced)
 {
 	return container_of(ced, struct sh_mtu2_priv, ced);
 }

 static void sh_mtu2_clock_event_mode(enum clock_event_mode mode,
 				    struct clock_event_device *ced)
 {
 	struct sh_mtu2_priv *p = ced_to_sh_mtu2(ced);
 	int disabled = 0;

 	/* deal with old setting first */
 	switch (ced->mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
 		sh_mtu2_disable(p);
 		disabled = 1;
 		break;
 	default:
 		break;
 	}

 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
 		pr_info("sh_mtu2: %s used for periodic clock events\n",
 			ced->name);
 		sh_mtu2_enable(p);
 		break;
 	case CLOCK_EVT_MODE_UNUSED:
 		if (!disabled)
 			sh_mtu2_disable(p);
 		break;
 	case CLOCK_EVT_MODE_SHUTDOWN:
 	default:
 		break;
 	}
 }

 static void sh_mtu2_register_clockevent(struct sh_mtu2_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->rating = rating;
 	ced->cpumask = cpumask_of(0);
 	ced->set_mode = sh_mtu2_clock_event_mode;

 	pr_info("sh_mtu2: %s used for clock events\n", ced->name);
 	clockevents_register_device(ced);

 	ret = setup_irq(p->irqaction.irq, &p->irqaction);
 	if (ret) {
 		pr_err("sh_mtu2: failed to request irq %d\n",
 		       p->irqaction.irq);
 		return;
 	}
 }

 static int sh_mtu2_register(struct sh_mtu2_priv *p, char *name,
 			    unsigned long clockevent_rating)
 {
 	if (clockevent_rating)
 		sh_mtu2_register_clockevent(p, name, clockevent_rating);

 	return 0;
 }

 static int sh_mtu2_setup(struct sh_mtu2_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) {
 		pr_err("sh_mtu2: failed to remap I/O memory\n");
 		goto err0;
 	}

 	/* setup data for setup_irq() (too early for request_irq()) */
 	p->irqaction.name = cfg->name;
 	p->irqaction.handler = sh_mtu2_interrupt;
 	p->irqaction.dev_id = p;
 	p->irqaction.irq = irq;
 	p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL;

 	/* get hold of clock */
 	p->clk = clk_get(&p->pdev->dev, cfg->clk);
 	if (IS_ERR(p->clk)) {
 		pr_err("sh_mtu2: cannot get clock \"%s\"\n", cfg->clk);
 		ret = PTR_ERR(p->clk);
 		goto err1;
 	}

 	return sh_mtu2_register(p, cfg->name, cfg->clockevent_rating);
  err1:
 	iounmap(p->mapbase);
  err0:
 	return ret;
 }

 static int __devinit sh_mtu2_probe(struct platform_device *pdev)
 {
 	struct sh_mtu2_priv *p = platform_get_drvdata(pdev);
 	struct sh_timer_config *cfg = pdev->dev.platform_data;
 	int ret;

 	if (p) {
 		pr_info("sh_mtu2: %s kept as earlytimer\n", cfg->name);
 		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_mtu2_setup(p, pdev);
 	if (ret) {
 		kfree(p);
 		platform_set_drvdata(pdev, NULL);
 	}
 	return ret;
 }

 static int __devexit sh_mtu2_remove(struct platform_device *pdev)
 {
 	return -EBUSY; /* cannot unregister clockevent */
 }

 static struct platform_driver sh_mtu2_device_driver = {
 	.probe		= sh_mtu2_probe,
 	.remove		= __devexit_p(sh_mtu2_remove),
 	.driver		= {
 		.name	= "sh_mtu2",
 	}
 };

 static int __init sh_mtu2_init(void)
 {
 	return platform_driver_register(&sh_mtu2_device_driver);
 }

 static void __exit sh_mtu2_exit(void)
 {
 	platform_driver_unregister(&sh_mtu2_device_driver);
 }

 early_platform_init("earlytimer", &sh_mtu2_device_driver);
 module_init(sh_mtu2_init);
 module_exit(sh_mtu2_exit);

 MODULE_AUTHOR("Magnus Damm");
 MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* SuperH Timer Support - MTU2
	*
	* 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/irq.h>
	#include <linux/err.h>
	#include <linux/clockchips.h>
	#include <linux/sh_timer.h>
	#include <linux/slab.h>

	struct sh_mtu2_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;
	};

	static DEFINE_SPINLOCK(sh_mtu2_lock);

	#define TSTR -1 /* shared register */
	#define TCR 0 /* channel register */
	#define TMDR 1 /* channel register */
	#define TIOR 2 /* channel register */
	#define TIER 3 /* channel register */
	#define TSR 4 /* channel register */
	#define TCNT 5 /* channel register */
	#define TGR 6 /* channel register */

	static unsigned long mtu2_reg_offs[] = {
	[TCR] = 0,
	[TMDR] = 1,
	[TIOR] = 2,
	[TIER] = 4,
	[TSR] = 5,
	[TCNT] = 6,
	[TGR] = 8,
	};

	static inline unsigned long sh_mtu2_read(struct sh_mtu2_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 = mtu2_reg_offs[reg_nr];

	if ((reg_nr == TCNT) \|\| (reg_nr == TGR))
	return ioread16(base + offs);
	else
	return ioread8(base + offs);
	}

	static inline void sh_mtu2_write(struct sh_mtu2_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 = mtu2_reg_offs[reg_nr];

	if ((reg_nr == TCNT) \|\| (reg_nr == TGR))
	iowrite16(value, base + offs);
	else
	iowrite8(value, base + offs);
	}

	static void sh_mtu2_start_stop_ch(struct sh_mtu2_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_mtu2_lock, flags);
	value = sh_mtu2_read(p, TSTR);

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

	sh_mtu2_write(p, TSTR, value);
	spin_unlock_irqrestore(&sh_mtu2_lock, flags);
	}

	static int sh_mtu2_enable(struct sh_mtu2_priv *p)
	{
	struct sh_timer_config *cfg = p->pdev->dev.platform_data;
	int ret;

	/* enable clock */
	ret = clk_enable(p->clk);
	if (ret) {
	pr_err("sh_mtu2: cannot enable clock \"%s\"\n", cfg->clk);
	return ret;
	}

	/* make sure channel is disabled */
	sh_mtu2_start_stop_ch(p, 0);

	p->rate = clk_get_rate(p->clk) / 64;
	p->periodic = (p->rate + HZ/2) / HZ;

	/* "Periodic Counter Operation" */
	sh_mtu2_write(p, TCR, 0x23); /* TGRA clear, divide clock by 64 */
	sh_mtu2_write(p, TIOR, 0);
	sh_mtu2_write(p, TGR, p->periodic);
	sh_mtu2_write(p, TCNT, 0);
	sh_mtu2_write(p, TMDR, 0);
	sh_mtu2_write(p, TIER, 0x01);

	/* enable channel */
	sh_mtu2_start_stop_ch(p, 1);

	return 0;
	}

	static void sh_mtu2_disable(struct sh_mtu2_priv *p)
	{
	/* disable channel */
	sh_mtu2_start_stop_ch(p, 0);

	/* stop clock */
	clk_disable(p->clk);
	}

	static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
	{
	struct sh_mtu2_priv *p = dev_id;

	/* acknowledge interrupt */
	sh_mtu2_read(p, TSR);
	sh_mtu2_write(p, TSR, 0xfe);

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

	static struct sh_mtu2_priv ced_to_sh_mtu2(struct clock_event_device ced)
	{
	return container_of(ced, struct sh_mtu2_priv, ced);
	}

	static void sh_mtu2_clock_event_mode(enum clock_event_mode mode,
	struct clock_event_device *ced)
	{
	struct sh_mtu2_priv *p = ced_to_sh_mtu2(ced);
	int disabled = 0;

	/* deal with old setting first */
	switch (ced->mode) {
	case CLOCK_EVT_MODE_PERIODIC:
	sh_mtu2_disable(p);
	disabled = 1;
	break;
	default:
	break;
	}

	switch (mode) {
	case CLOCK_EVT_MODE_PERIODIC:
	pr_info("sh_mtu2: %s used for periodic clock events\n",
	ced->name);
	sh_mtu2_enable(p);
	break;
	case CLOCK_EVT_MODE_UNUSED:
	if (!disabled)
	sh_mtu2_disable(p);
	break;
	case CLOCK_EVT_MODE_SHUTDOWN:
	default:
	break;
	}
	}

	static void sh_mtu2_register_clockevent(struct sh_mtu2_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->rating = rating;
	ced->cpumask = cpumask_of(0);
	ced->set_mode = sh_mtu2_clock_event_mode;

	pr_info("sh_mtu2: %s used for clock events\n", ced->name);
	clockevents_register_device(ced);

	ret = setup_irq(p->irqaction.irq, &p->irqaction);
	if (ret) {
	pr_err("sh_mtu2: failed to request irq %d\n",
	p->irqaction.irq);
	return;
	}
	}

	static int sh_mtu2_register(struct sh_mtu2_priv p, char name,
	unsigned long clockevent_rating)
	{
	if (clockevent_rating)
	sh_mtu2_register_clockevent(p, name, clockevent_rating);

	return 0;
	}

	static int sh_mtu2_setup(struct sh_mtu2_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) {
	pr_err("sh_mtu2: failed to remap I/O memory\n");
	goto err0;
	}

	/* setup data for setup_irq() (too early for request_irq()) */
	p->irqaction.name = cfg->name;
	p->irqaction.handler = sh_mtu2_interrupt;
	p->irqaction.dev_id = p;
	p->irqaction.irq = irq;
	p->irqaction.flags = IRQF_DISABLED \| IRQF_TIMER \| IRQF_IRQPOLL;

	/* get hold of clock */
	p->clk = clk_get(&p->pdev->dev, cfg->clk);
	if (IS_ERR(p->clk)) {
	pr_err("sh_mtu2: cannot get clock \"%s\"\n", cfg->clk);
	ret = PTR_ERR(p->clk);
	goto err1;
	}

	return sh_mtu2_register(p, cfg->name, cfg->clockevent_rating);
	err1:
	iounmap(p->mapbase);
	err0:
	return ret;
	}

	static int __devinit sh_mtu2_probe(struct platform_device *pdev)
	{
	struct sh_mtu2_priv *p = platform_get_drvdata(pdev);
	struct sh_timer_config *cfg = pdev->dev.platform_data;
	int ret;

	if (p) {
	pr_info("sh_mtu2: %s kept as earlytimer\n", cfg->name);
	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_mtu2_setup(p, pdev);
	if (ret) {
	kfree(p);
	platform_set_drvdata(pdev, NULL);
	}
	return ret;
	}

	static int __devexit sh_mtu2_remove(struct platform_device *pdev)
	{
	return -EBUSY; /* cannot unregister clockevent */
	}

	static struct platform_driver sh_mtu2_device_driver = {
	.probe = sh_mtu2_probe,
	.remove = __devexit_p(sh_mtu2_remove),
	.driver = {
	.name = "sh_mtu2",
	}
	};

	static int __init sh_mtu2_init(void)
	{
	return platform_driver_register(&sh_mtu2_device_driver);
	}

	static void __exit sh_mtu2_exit(void)
	{
	platform_driver_unregister(&sh_mtu2_device_driver);
	}

	early_platform_init("earlytimer", &sh_mtu2_device_driver);
	module_init(sh_mtu2_init);
	module_exit(sh_mtu2_exit);

	MODULE_AUTHOR("Magnus Damm");
	MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
	MODULE_LICENSE("GPL v2");