1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/clocksource/h8300_tpu.c b/drivers/clocksource/h8300_tpu.c
new file mode 100644
index 000000000..17d4ab0f6
--- /dev/null
+++ b/drivers/clocksource/h8300_tpu.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  H8S TPU Driver
+ *
+ *  Copyright 2015 Yoshinori Sato <ysato@users.sourcefoge.jp>
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clocksource.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define TCR	0x0
+#define TSR	0x5
+#define TCNT	0x6
+
+#define TCFV	0x10
+
+struct tpu_priv {
+	struct clocksource cs;
+	void __iomem *mapbase1;
+	void __iomem *mapbase2;
+	raw_spinlock_t lock;
+	unsigned int cs_enabled;
+};
+
+static inline unsigned long read_tcnt32(struct tpu_priv *p)
+{
+	unsigned long tcnt;
+
+	tcnt = ioread16be(p->mapbase1 + TCNT) << 16;
+	tcnt |= ioread16be(p->mapbase2 + TCNT);
+	return tcnt;
+}
+
+static int tpu_get_counter(struct tpu_priv *p, unsigned long long *val)
+{
+	unsigned long v1, v2, v3;
+	int o1, o2;
+
+	o1 = ioread8(p->mapbase1 + TSR) & TCFV;
+
+	/* Make sure the timer value is stable. Stolen from acpi_pm.c */
+	do {
+		o2 = o1;
+		v1 = read_tcnt32(p);
+		v2 = read_tcnt32(p);
+		v3 = read_tcnt32(p);
+		o1 = ioread8(p->mapbase1 + TSR) & TCFV;
+	} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
+			  || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
+
+	*val = v2;
+	return o1;
+}
+
+static inline struct tpu_priv *cs_to_priv(struct clocksource *cs)
+{
+	return container_of(cs, struct tpu_priv, cs);
+}
+
+static u64 tpu_clocksource_read(struct clocksource *cs)
+{
+	struct tpu_priv *p = cs_to_priv(cs);
+	unsigned long flags;
+	unsigned long long value;
+
+	raw_spin_lock_irqsave(&p->lock, flags);
+	if (tpu_get_counter(p, &value))
+		value += 0x100000000;
+	raw_spin_unlock_irqrestore(&p->lock, flags);
+
+	return value;
+}
+
+static int tpu_clocksource_enable(struct clocksource *cs)
+{
+	struct tpu_priv *p = cs_to_priv(cs);
+
+	WARN_ON(p->cs_enabled);
+
+	iowrite16be(0, p->mapbase1 + TCNT);
+	iowrite16be(0, p->mapbase2 + TCNT);
+	iowrite8(0x0f, p->mapbase1 + TCR);
+	iowrite8(0x03, p->mapbase2 + TCR);
+
+	p->cs_enabled = true;
+	return 0;
+}
+
+static void tpu_clocksource_disable(struct clocksource *cs)
+{
+	struct tpu_priv *p = cs_to_priv(cs);
+
+	WARN_ON(!p->cs_enabled);
+
+	iowrite8(0, p->mapbase1 + TCR);
+	iowrite8(0, p->mapbase2 + TCR);
+	p->cs_enabled = false;
+}
+
+static struct tpu_priv tpu_priv = {
+	.cs = {
+		.name = "H8S_TPU",
+		.rating = 200,
+		.read = tpu_clocksource_read,
+		.enable = tpu_clocksource_enable,
+		.disable = tpu_clocksource_disable,
+		.mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8),
+		.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+	},
+};
+
+#define CH_L 0
+#define CH_H 1
+
+static int __init h8300_tpu_init(struct device_node *node)
+{
+	void __iomem *base[2];
+	struct clk *clk;
+	int ret = -ENXIO;
+
+	clk = of_clk_get(node, 0);
+	if (IS_ERR(clk)) {
+		pr_err("failed to get clock for clocksource\n");
+		return PTR_ERR(clk);
+	}
+
+	base[CH_L] = of_iomap(node, CH_L);
+	if (!base[CH_L]) {
+		pr_err("failed to map registers for clocksource\n");
+		goto free_clk;
+	}
+	base[CH_H] = of_iomap(node, CH_H);
+	if (!base[CH_H]) {
+		pr_err("failed to map registers for clocksource\n");
+		goto unmap_L;
+	}
+
+	tpu_priv.mapbase1 = base[CH_L];
+	tpu_priv.mapbase2 = base[CH_H];
+
+	return clocksource_register_hz(&tpu_priv.cs, clk_get_rate(clk) / 64);
+
+unmap_L:
+	iounmap(base[CH_H]);
+free_clk:
+	clk_put(clk);
+	return ret;
+}
+
+TIMER_OF_DECLARE(h8300_tpu, "renesas,tpu", h8300_tpu_init);