h8300: clocksource

h8300_timer8: 8bit clockevent device
h8300_timer16 / h8300_tpu: 16bit clocksource

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>

1 files changed, 254 insertions, 0 deletions

diff --git a/drivers/clocksource/h8300_timer16.c b/drivers/clocksource/h8300_timer16.c
new file mode 100644
index 000000000000..82941c1e9e33
--- /dev/null
+++ b/drivers/clocksource/h8300_timer16.c
@@ -0,0 +1,254 @@
+/*
+ *  H8/300 16bit Timer driver
+ *
+ *  Copyright 2015 Yoshinori Sato <ysato@users.sourcefoge.jp>
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/clocksource.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <asm/segment.h>
+#include <asm/irq.h>
+
+#define TSTR	0
+#define TSNC	1
+#define TMDR	2
+#define TOLR	3
+#define TISRA	4
+#define TISRB	5
+#define TISRC	6
+
+#define TCR	0
+#define TIOR	1
+#define TCNT	2
+#define GRA	4
+#define GRB	6
+
+#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 timer16_priv {
+	struct platform_device *pdev;
+	struct clocksource cs;
+	struct irqaction irqaction;
+	unsigned long total_cycles;
+	unsigned long mapbase;
+	unsigned long mapcommon;
+	unsigned long flags;
+	unsigned short gra;
+	unsigned short cs_enabled;
+	unsigned char enb;
+	unsigned char imfa;
+	unsigned char imiea;
+	unsigned char ovf;
+	raw_spinlock_t lock;
+	struct clk *clk;
+};
+
+static unsigned long timer16_get_counter(struct timer16_priv *p)
+{
+	unsigned long v1, v2, v3;
+	int o1, o2;
+
+	o1 = ctrl_inb(p->mapcommon + TISRC) & p->ovf;
+
+	/* Make sure the timer value is stable. Stolen from acpi_pm.c */
+	do {
+		o2 = o1;
+		v1 = ctrl_inw(p->mapbase + TCNT);
+		v2 = ctrl_inw(p->mapbase + TCNT);
+		v3 = ctrl_inw(p->mapbase + TCNT);
+		o1 = ctrl_inb(p->mapcommon + TISRC) & p->ovf;
+	} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
+			  || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
+
+	v2 |= 0x10000;
+	return v2;
+}
+
+
+static irqreturn_t timer16_interrupt(int irq, void *dev_id)
+{
+	struct timer16_priv *p = (struct timer16_priv *)dev_id;
+
+	ctrl_outb(ctrl_inb(p->mapcommon + TISRA) & ~p->imfa,
+		  p->mapcommon + TISRA);
+	p->total_cycles += 0x10000;
+
+	return IRQ_HANDLED;
+}
+
+static inline struct timer16_priv *cs_to_priv(struct clocksource *cs)
+{
+	return container_of(cs, struct timer16_priv, cs);
+}
+
+static cycle_t timer16_clocksource_read(struct clocksource *cs)
+{
+	struct timer16_priv *p = cs_to_priv(cs);
+	unsigned long flags, raw;
+	unsigned long value;
+
+	raw_spin_lock_irqsave(&p->lock, flags);
+	value = p->total_cycles;
+	raw = timer16_get_counter(p);
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+
+	return value + raw;
+}
+
+static int timer16_enable(struct clocksource *cs)
+{
+	struct timer16_priv *p = cs_to_priv(cs);
+
+	WARN_ON(p->cs_enabled);
+
+	p->total_cycles = 0;
+	ctrl_outw(0x0000, p->mapbase + TCNT);
+	ctrl_outb(0x83, p->mapbase + TCR);
+	ctrl_outb(ctrl_inb(p->mapcommon + TSTR) | p->enb,
+		  p->mapcommon + TSTR);
+
+	p->cs_enabled = true;
+	return 0;
+}
+
+static void timer16_disable(struct clocksource *cs)
+{
+	struct timer16_priv *p = cs_to_priv(cs);
+
+	WARN_ON(!p->cs_enabled);
+
+	ctrl_outb(ctrl_inb(p->mapcommon + TSTR) & ~p->enb,
+		  p->mapcommon + TSTR);
+
+	p->cs_enabled = false;
+}
+
+#define REG_CH   0
+#define REG_COMM 1
+
+static int timer16_setup(struct timer16_priv *p, struct platform_device *pdev)
+{
+	struct resource *res[2];
+	int ret, irq;
+	unsigned int ch;
+
+	memset(p, 0, sizeof(*p));
+	p->pdev = pdev;
+
+	res[REG_CH] = platform_get_resource(p->pdev,
+					    IORESOURCE_MEM, REG_CH);
+	res[REG_COMM] = platform_get_resource(p->pdev,
+					      IORESOURCE_MEM, REG_COMM);
+	if (!res[REG_CH] || !res[REG_COMM]) {
+		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 irq;
+	}
+
+	p->clk = clk_get(&p->pdev->dev, "fck");
+	if (IS_ERR(p->clk)) {
+		dev_err(&p->pdev->dev, "can't get clk\n");
+		return PTR_ERR(p->clk);
+	}
+	of_property_read_u32(p->pdev->dev.of_node, "renesas,channel", &ch);
+
+	p->pdev = pdev;
+	p->mapbase = res[REG_CH]->start;
+	p->mapcommon = res[REG_COMM]->start;
+	p->enb = 1 << ch;
+	p->imfa = 1 << ch;
+	p->imiea = 1 << (4 + ch);
+	p->cs.name = pdev->name;
+	p->cs.rating = 200;
+	p->cs.read = timer16_clocksource_read;
+	p->cs.enable = timer16_enable;
+	p->cs.disable = timer16_disable;
+	p->cs.mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
+	p->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	ret = request_irq(irq, timer16_interrupt,
+			  IRQF_TIMER, pdev->name, p);
+	if (ret < 0) {
+		dev_err(&p->pdev->dev, "failed to request irq %d\n", irq);
+		return ret;
+	}
+
+	clocksource_register_hz(&p->cs, clk_get_rate(p->clk) / 8);
+
+	return 0;
+}
+
+static int timer16_probe(struct platform_device *pdev)
+{
+	struct timer16_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 timer16_setup(p, pdev);
+}
+
+static int timer16_remove(struct platform_device *pdev)
+{
+	return -EBUSY;
+}
+
+static const struct of_device_id timer16_of_table[] = {
+	{ .compatible = "renesas,16bit-timer" },
+	{ }
+};
+static struct platform_driver timer16_driver = {
+	.probe		= timer16_probe,
+	.remove		= timer16_remove,
+	.driver		= {
+		.name	= "h8300h-16timer",
+		.of_match_table = of_match_ptr(timer16_of_table),
+	}
+};
+
+static int __init timer16_init(void)
+{
+	return platform_driver_register(&timer16_driver);
+}
+
+static void __exit timer16_exit(void)
+{
+	platform_driver_unregister(&timer16_driver);
+}
+
+subsys_initcall(timer16_init);
+module_exit(timer16_exit);
+MODULE_AUTHOR("Yoshinori Sato");
+MODULE_DESCRIPTION("H8/300H 16bit Timer Driver");
+MODULE_LICENSE("GPL v2");