drivers/clocksource/h8300_timer8.c - kernel/bruno - Git at Google

 /*
  *  linux/arch/h8300/kernel/cpu/timer/timer8.c
  *
  *  Yoshinori Sato <ysato@users.sourcefoge.jp>
  *
  *  8bit Timer driver
  *
  */

 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/clockchips.h>
 #include <linux/module.h>
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/of.h>

 #include <asm/irq.h>

 #define _8TCR	0
 #define _8TCSR	2
 #define TCORA	4
 #define TCORB	6
 #define _8TCNT	8

 #define FLAG_REPROGRAM (1 << 0)
 #define FLAG_SKIPEVENT (1 << 1)
 #define FLAG_IRQCONTEXT (1 << 2)
 #define FLAG_STARTED (1 << 3)

 #define ONESHOT  0
 #define PERIODIC 1

 #define RELATIVE 0
 #define ABSOLUTE 1

 struct timer8_priv {
 	struct platform_device *pdev;
 	struct clock_event_device ced;
 	struct irqaction irqaction;
 	unsigned long mapbase;
 	raw_spinlock_t lock;
 	unsigned long flags;
 	unsigned int rate;
 	unsigned int tcora;
 	struct clk *pclk;
 };

 static unsigned long timer8_get_counter(struct timer8_priv *p)
 {
 	unsigned long v1, v2, v3;
 	int o1, o2;

 	o1 = ctrl_inb(p->mapbase + _8TCSR) & 0x20;

 	/* Make sure the timer value is stable. Stolen from acpi_pm.c */
 	do {
 		o2 = o1;
 		v1 = ctrl_inw(p->mapbase + _8TCNT);
 		v2 = ctrl_inw(p->mapbase + _8TCNT);
 		v3 = ctrl_inw(p->mapbase + _8TCNT);
 		o1 = ctrl_inb(p->mapbase + _8TCSR) & 0x20;
 	} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
 			  || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));

 	v2 |= o1 << 10;
 	return v2;
 }

 static irqreturn_t timer8_interrupt(int irq, void *dev_id)
 {
 	struct timer8_priv *p = dev_id;

 	ctrl_outb(ctrl_inb(p->mapbase + _8TCSR) & ~0x40,
 		  p->mapbase + _8TCSR);
 	p->flags |= FLAG_IRQCONTEXT;
 	ctrl_outw(p->tcora, p->mapbase + TCORA);
 	if (!(p->flags & FLAG_SKIPEVENT)) {
 		if (clockevent_state_oneshot(&p->ced))
 			ctrl_outw(0x0000, p->mapbase + _8TCR);
 		p->ced.event_handler(&p->ced);
 	}
 	p->flags &= ~(FLAG_SKIPEVENT | FLAG_IRQCONTEXT);

 	return IRQ_HANDLED;
 }

 static void timer8_set_next(struct timer8_priv *p, unsigned long delta)
 {
 	unsigned long flags;
 	unsigned long now;

 	raw_spin_lock_irqsave(&p->lock, flags);
 	if (delta >= 0x10000)
 		dev_warn(&p->pdev->dev, "delta out of range\n");
 	now = timer8_get_counter(p);
 	p->tcora = delta;
 	ctrl_outb(ctrl_inb(p->mapbase + _8TCR) | 0x40, p->mapbase + _8TCR);
 	if (delta > now)
 		ctrl_outw(delta, p->mapbase + TCORA);
 	else
 		ctrl_outw(now + 1, p->mapbase + TCORA);

 	raw_spin_unlock_irqrestore(&p->lock, flags);
 }

 static int timer8_enable(struct timer8_priv *p)
 {
 	p->rate = clk_get_rate(p->pclk) / 64;
 	ctrl_outw(0xffff, p->mapbase + TCORA);
 	ctrl_outw(0x0000, p->mapbase + _8TCNT);
 	ctrl_outw(0x0c02, p->mapbase + _8TCR);

 	return 0;
 }

 static int timer8_start(struct timer8_priv *p)
 {
 	int ret = 0;
 	unsigned long flags;

 	raw_spin_lock_irqsave(&p->lock, flags);

 	if (!(p->flags & FLAG_STARTED))
 		ret = timer8_enable(p);

 	if (ret)
 		goto out;
 	p->flags |= FLAG_STARTED;

  out:
 	raw_spin_unlock_irqrestore(&p->lock, flags);

 	return ret;
 }

 static void timer8_stop(struct timer8_priv *p)
 {
 	unsigned long flags;

 	raw_spin_lock_irqsave(&p->lock, flags);

 	ctrl_outw(0x0000, p->mapbase + _8TCR);

 	raw_spin_unlock_irqrestore(&p->lock, flags);
 }

 static inline struct timer8_priv *ced_to_priv(struct clock_event_device *ced)
 {
 	return container_of(ced, struct timer8_priv, ced);
 }

 static void timer8_clock_event_start(struct timer8_priv *p, int periodic)
 {
 	struct clock_event_device *ced = &p->ced;

 	timer8_start(p);

 	ced->shift = 32;
 	ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
 	ced->max_delta_ns = clockevent_delta2ns(0xffff, ced);
 	ced->min_delta_ns = clockevent_delta2ns(0x0001, ced);

 	timer8_set_next(p, periodic?(p->rate + HZ/2) / HZ:0x10000);
 }

 static int timer8_clock_event_shutdown(struct clock_event_device *ced)
 {
 	timer8_stop(ced_to_priv(ced));
 	return 0;
 }

 static int timer8_clock_event_periodic(struct clock_event_device *ced)
 {
 	struct timer8_priv *p = ced_to_priv(ced);

 	dev_info(&p->pdev->dev, "used for periodic clock events\n");
 	timer8_stop(p);
 	timer8_clock_event_start(p, PERIODIC);

 	return 0;
 }

 static int timer8_clock_event_oneshot(struct clock_event_device *ced)
 {
 	struct timer8_priv *p = ced_to_priv(ced);

 	dev_info(&p->pdev->dev, "used for oneshot clock events\n");
 	timer8_stop(p);
 	timer8_clock_event_start(p, ONESHOT);

 	return 0;
 }

 static int timer8_clock_event_next(unsigned long delta,
 				   struct clock_event_device *ced)
 {
 	struct timer8_priv *p = ced_to_priv(ced);

 	BUG_ON(!clockevent_state_oneshot(ced));
 	timer8_set_next(p, delta - 1);

 	return 0;
 }

 static int timer8_setup(struct timer8_priv *p,
 			struct platform_device *pdev)
 {
 	struct resource *res;
 	int irq;
 	int ret;

 	p->pdev = pdev;

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

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

 	p->mapbase = res->start;

 	p->irqaction.name = dev_name(&p->pdev->dev);
 	p->irqaction.handler = timer8_interrupt;
 	p->irqaction.dev_id = p;
 	p->irqaction.flags = IRQF_TIMER;

 	p->pclk = clk_get(&p->pdev->dev, "fck");
 	if (IS_ERR(p->pclk)) {
 		dev_err(&p->pdev->dev, "can't get clk\n");
 		return PTR_ERR(p->pclk);
 	}

 	p->ced.name = pdev->name;
 	p->ced.features = CLOCK_EVT_FEAT_PERIODIC |
 		CLOCK_EVT_FEAT_ONESHOT;
 	p->ced.rating = 200;
 	p->ced.cpumask = cpumask_of(0);
 	p->ced.set_next_event = timer8_clock_event_next;
 	p->ced.set_state_shutdown = timer8_clock_event_shutdown;
 	p->ced.set_state_periodic = timer8_clock_event_periodic;
 	p->ced.set_state_oneshot = timer8_clock_event_oneshot;

 	ret = setup_irq(irq, &p->irqaction);
 	if (ret < 0) {
 		dev_err(&p->pdev->dev,
 			"failed to request irq %d\n", irq);
 		return ret;
 	}
 	clockevents_register_device(&p->ced);
 	platform_set_drvdata(pdev, p);

 	return 0;
 }

 static int timer8_probe(struct platform_device *pdev)
 {
 	struct timer8_priv *p = platform_get_drvdata(pdev);

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

 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;

 	return timer8_setup(p, pdev);
 }

 static int timer8_remove(struct platform_device *pdev)
 {
 	return -EBUSY;
 }

 static const struct of_device_id timer8_of_table[] __maybe_unused = {
 	{ .compatible = "renesas,8bit-timer" },
 	{ }
 };

 MODULE_DEVICE_TABLE(of, timer8_of_table);
 static struct platform_driver timer8_driver = {
 	.probe		= timer8_probe,
 	.remove		= timer8_remove,
 	.driver		= {
 		.name	= "h8300-8timer",
 		.of_match_table = of_match_ptr(timer8_of_table),
 	}
 };

 static int __init timer8_init(void)
 {
 	return platform_driver_register(&timer8_driver);
 }

 static void __exit timer8_exit(void)
 {
 	platform_driver_unregister(&timer8_driver);
 }

 subsys_initcall(timer8_init);
 module_exit(timer8_exit);
 MODULE_AUTHOR("Yoshinori Sato");
 MODULE_DESCRIPTION("H8/300 8bit Timer Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* linux/arch/h8300/kernel/cpu/timer/timer8.c
	*
	* Yoshinori Sato <ysato@users.sourcefoge.jp>
	*
	* 8bit Timer driver
	*
	*/

	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/interrupt.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/clockchips.h>
	#include <linux/module.h>
	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/of.h>

	#include <asm/irq.h>

	#define _8TCR 0
	#define _8TCSR 2
	#define TCORA 4
	#define TCORB 6
	#define _8TCNT 8

	#define FLAG_REPROGRAM (1 << 0)
	#define FLAG_SKIPEVENT (1 << 1)
	#define FLAG_IRQCONTEXT (1 << 2)
	#define FLAG_STARTED (1 << 3)

	#define ONESHOT 0
	#define PERIODIC 1

	#define RELATIVE 0
	#define ABSOLUTE 1

	struct timer8_priv {
	struct platform_device *pdev;
	struct clock_event_device ced;
	struct irqaction irqaction;
	unsigned long mapbase;
	raw_spinlock_t lock;
	unsigned long flags;
	unsigned int rate;
	unsigned int tcora;
	struct clk *pclk;
	};

	static unsigned long timer8_get_counter(struct timer8_priv *p)
	{
	unsigned long v1, v2, v3;
	int o1, o2;

	o1 = ctrl_inb(p->mapbase + _8TCSR) & 0x20;

	/* Make sure the timer value is stable. Stolen from acpi_pm.c */
	do {
	o2 = o1;
	v1 = ctrl_inw(p->mapbase + _8TCNT);
	v2 = ctrl_inw(p->mapbase + _8TCNT);
	v3 = ctrl_inw(p->mapbase + _8TCNT);
	o1 = ctrl_inb(p->mapbase + _8TCSR) & 0x20;
	} while (unlikely((o1 != o2) \|\| (v1 > v2 && v1 < v3)
	\|\| (v2 > v3 && v2 < v1) \|\| (v3 > v1 && v3 < v2)));

	v2 \|= o1 << 10;
	return v2;
	}

	static irqreturn_t timer8_interrupt(int irq, void *dev_id)
	{
	struct timer8_priv *p = dev_id;

	ctrl_outb(ctrl_inb(p->mapbase + _8TCSR) & ~0x40,
	p->mapbase + _8TCSR);
	p->flags \|= FLAG_IRQCONTEXT;
	ctrl_outw(p->tcora, p->mapbase + TCORA);
	if (!(p->flags & FLAG_SKIPEVENT)) {
	if (clockevent_state_oneshot(&p->ced))
	ctrl_outw(0x0000, p->mapbase + _8TCR);
	p->ced.event_handler(&p->ced);
	}
	p->flags &= ~(FLAG_SKIPEVENT \| FLAG_IRQCONTEXT);

	return IRQ_HANDLED;
	}

	static void timer8_set_next(struct timer8_priv *p, unsigned long delta)
	{
	unsigned long flags;
	unsigned long now;

	raw_spin_lock_irqsave(&p->lock, flags);
	if (delta >= 0x10000)
	dev_warn(&p->pdev->dev, "delta out of range\n");
	now = timer8_get_counter(p);
	p->tcora = delta;
	ctrl_outb(ctrl_inb(p->mapbase + _8TCR) \| 0x40, p->mapbase + _8TCR);
	if (delta > now)
	ctrl_outw(delta, p->mapbase + TCORA);
	else
	ctrl_outw(now + 1, p->mapbase + TCORA);

	raw_spin_unlock_irqrestore(&p->lock, flags);
	}

	static int timer8_enable(struct timer8_priv *p)
	{
	p->rate = clk_get_rate(p->pclk) / 64;
	ctrl_outw(0xffff, p->mapbase + TCORA);
	ctrl_outw(0x0000, p->mapbase + _8TCNT);
	ctrl_outw(0x0c02, p->mapbase + _8TCR);

	return 0;
	}

	static int timer8_start(struct timer8_priv *p)
	{
	int ret = 0;
	unsigned long flags;

	raw_spin_lock_irqsave(&p->lock, flags);

	if (!(p->flags & FLAG_STARTED))
	ret = timer8_enable(p);

	if (ret)
	goto out;
	p->flags \|= FLAG_STARTED;

	out:
	raw_spin_unlock_irqrestore(&p->lock, flags);

	return ret;
	}

	static void timer8_stop(struct timer8_priv *p)
	{
	unsigned long flags;

	raw_spin_lock_irqsave(&p->lock, flags);

	ctrl_outw(0x0000, p->mapbase + _8TCR);

	raw_spin_unlock_irqrestore(&p->lock, flags);
	}

	static inline struct timer8_priv ced_to_priv(struct clock_event_device ced)
	{
	return container_of(ced, struct timer8_priv, ced);
	}

	static void timer8_clock_event_start(struct timer8_priv *p, int periodic)
	{
	struct clock_event_device *ced = &p->ced;

	timer8_start(p);

	ced->shift = 32;
	ced->mult = div_sc(p->rate, NSEC_PER_SEC, ced->shift);
	ced->max_delta_ns = clockevent_delta2ns(0xffff, ced);
	ced->min_delta_ns = clockevent_delta2ns(0x0001, ced);

	timer8_set_next(p, periodic?(p->rate + HZ/2) / HZ:0x10000);
	}

	static int timer8_clock_event_shutdown(struct clock_event_device *ced)
	{
	timer8_stop(ced_to_priv(ced));
	return 0;
	}

	static int timer8_clock_event_periodic(struct clock_event_device *ced)
	{
	struct timer8_priv *p = ced_to_priv(ced);

	dev_info(&p->pdev->dev, "used for periodic clock events\n");
	timer8_stop(p);
	timer8_clock_event_start(p, PERIODIC);

	return 0;
	}

	static int timer8_clock_event_oneshot(struct clock_event_device *ced)
	{
	struct timer8_priv *p = ced_to_priv(ced);

	dev_info(&p->pdev->dev, "used for oneshot clock events\n");
	timer8_stop(p);
	timer8_clock_event_start(p, ONESHOT);

	return 0;
	}

	static int timer8_clock_event_next(unsigned long delta,
	struct clock_event_device *ced)
	{
	struct timer8_priv *p = ced_to_priv(ced);

	BUG_ON(!clockevent_state_oneshot(ced));
	timer8_set_next(p, delta - 1);

	return 0;
	}

	static int timer8_setup(struct timer8_priv *p,
	struct platform_device *pdev)
	{
	struct resource *res;
	int irq;
	int ret;

	p->pdev = pdev;

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

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

	p->mapbase = res->start;

	p->irqaction.name = dev_name(&p->pdev->dev);
	p->irqaction.handler = timer8_interrupt;
	p->irqaction.dev_id = p;
	p->irqaction.flags = IRQF_TIMER;

	p->pclk = clk_get(&p->pdev->dev, "fck");
	if (IS_ERR(p->pclk)) {
	dev_err(&p->pdev->dev, "can't get clk\n");
	return PTR_ERR(p->pclk);
	}

	p->ced.name = pdev->name;
	p->ced.features = CLOCK_EVT_FEAT_PERIODIC \|
	CLOCK_EVT_FEAT_ONESHOT;
	p->ced.rating = 200;
	p->ced.cpumask = cpumask_of(0);
	p->ced.set_next_event = timer8_clock_event_next;
	p->ced.set_state_shutdown = timer8_clock_event_shutdown;
	p->ced.set_state_periodic = timer8_clock_event_periodic;
	p->ced.set_state_oneshot = timer8_clock_event_oneshot;

	ret = setup_irq(irq, &p->irqaction);
	if (ret < 0) {
	dev_err(&p->pdev->dev,
	"failed to request irq %d\n", irq);
	return ret;
	}
	clockevents_register_device(&p->ced);
	platform_set_drvdata(pdev, p);

	return 0;
	}

	static int timer8_probe(struct platform_device *pdev)
	{
	struct timer8_priv *p = platform_get_drvdata(pdev);

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

	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
	if (!p)
	return -ENOMEM;

	return timer8_setup(p, pdev);
	}

	static int timer8_remove(struct platform_device *pdev)
	{
	return -EBUSY;
	}

	static const struct of_device_id timer8_of_table[] __maybe_unused = {
	{ .compatible = "renesas,8bit-timer" },
	{ }
	};

	MODULE_DEVICE_TABLE(of, timer8_of_table);
	static struct platform_driver timer8_driver = {
	.probe = timer8_probe,
	.remove = timer8_remove,
	.driver = {
	.name = "h8300-8timer",
	.of_match_table = of_match_ptr(timer8_of_table),
	}
	};

	static int __init timer8_init(void)
	{
	return platform_driver_register(&timer8_driver);
	}

	static void __exit timer8_exit(void)
	{
	platform_driver_unregister(&timer8_driver);
	}

	subsys_initcall(timer8_init);
	module_exit(timer8_exit);
	MODULE_AUTHOR("Yoshinori Sato");
	MODULE_DESCRIPTION("H8/300 8bit Timer Driver");
	MODULE_LICENSE("GPL v2");