[1/2] clocksource/drivers: Add timer-of common init routine

diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index ec55921..72bfd00 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,3 +1,4 @@ 
+obj-$(CONFIG_TIMER_OF)		+= timer-of.o
 obj-$(CONFIG_TIMER_PROBE)	+= timer-probe.o
 obj-$(CONFIG_ATMEL_PIT)		+= timer-atmel-pit.o
 obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
new file mode 100644
index 0000000..f25dc72
--- /dev/null
+++ b/drivers/clocksource/timer-of.c
@@ -0,0 +1,168 @@ 
+/*
+ * Copyright (c) 2017, Linaro Ltd.  All rights reserved.
+ *
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+#include "timer-of.h"
+
+static __init void timer_irq_exit(struct of_timer_irq *of_irq)
+{
+	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
+
+	struct clock_event_device *clkevt = &to->clkevt;
+
+	of_irq->percpu ? free_percpu_irq(of_irq->irq, clkevt) :
+		free_irq(of_irq->irq, clkevt);
+}
+
+static __init int timer_irq_init(struct device_node *np,
+				 struct of_timer_irq *of_irq)
+{
+	int ret;
+	struct timer_of *to = container_of(of_irq, struct timer_of, of_irq);
+	struct clock_event_device *clkevt = &to->clkevt;
+
+	of_irq->irq = of_irq->name ? of_irq_get_byname(np, of_irq->name):
+		irq_of_parse_and_map(np, of_irq->index);
+	if (!of_irq->irq) {
+		pr_err("Failed to map interrupt for %s\n", np->full_name);
+		return -EINVAL;
+	}
+
+	ret = of_irq->percpu ?
+		request_percpu_irq(of_irq->irq, of_irq->handler,
+				   np->full_name, clkevt) :
+		request_irq(of_irq->irq, of_irq->handler, IRQF_TIMER,
+			    np->full_name, clkevt);
+	if (ret) {
+		pr_err("Failed to request irq %d for %s\n", of_irq->irq,
+		       np->full_name);
+		return ret;
+	}
+
+	clkevt->irq = of_irq->irq;
+
+	return 0;
+}
+
+static __init void timer_clk_exit(struct of_timer_clk *of_clk)
+{
+	of_clk->rate = 0;
+	clk_disable_unprepare(of_clk->clk);
+	clk_put(of_clk->clk);
+}
+
+static __init int timer_clk_init(struct device_node *np,
+				 struct of_timer_clk *of_clk)
+{
+	int ret;
+
+	of_clk->clk = of_clk->name ? of_clk_get_by_name(np, of_clk->name) :
+		of_clk_get(np, of_clk->index);
+	if (IS_ERR(of_clk->clk)) {
+		pr_err("Failed to get clock for %s\n", np->full_name);
+		return PTR_ERR(of_clk->clk);
+	}
+
+	ret = clk_prepare_enable(of_clk->clk);
+	if (ret) {
+		pr_err("Failed for enable clock for %s\n", np->full_name);
+		goto out_clk_put;
+	}
+
+	of_clk->rate = clk_get_rate(of_clk->clk);
+	if (!of_clk->rate) {
+		ret = -EINVAL;
+		pr_err("Failed to get clock rate for %s\n", np->full_name);
+		goto out_clk_disable;
+	}
+
+	of_clk->period = DIV_ROUND_UP(of_clk->rate, HZ);
+out:
+	return ret;
+
+out_clk_disable:
+	clk_disable_unprepare(of_clk->clk);
+out_clk_put:
+	clk_put(of_clk->clk);
+
+	goto out;
+}
+
+static __init void timer_base_exit(struct of_timer_base *of_base)
+{
+	iounmap(of_base->base);
+}
+
+static __init int timer_base_init(struct device_node *np,
+				  struct of_timer_base *of_base)
+{
+	const char *name = of_base->name ? of_base->name : np->full_name;
+
+	of_base->base = of_io_request_and_map(np, of_base->index, name);
+	if (of_base->base) {
+		pr_err("Failed to iomap (%s)\n", name);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+int __init timer_of_init(struct device_node *np, struct timer_of *to)
+{
+	int ret;
+	int flags = 0;
+
+	if (to->flags & TIMER_OF_BASE) {
+		ret = timer_base_init(np, &to->of_base);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_BASE;
+	}
+
+	if (to->flags & TIMER_OF_CLOCK) {
+		ret = timer_clk_init(np, &to->of_clk);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_CLOCK;
+	}
+
+	if (to->flags & TIMER_OF_IRQ) {
+		ret = timer_irq_init(np, &to->of_irq);
+		if (ret)
+			goto out_fail;
+		flags |= TIMER_OF_IRQ;
+	}
+out:
+	return ret;
+
+out_fail:
+	if (flags & TIMER_OF_IRQ)
+		timer_irq_exit(&to->of_irq);
+
+	if (flags & TIMER_OF_CLOCK)
+		timer_clk_exit(&to->of_clk);
+
+	if (flags & TIMER_OF_BASE)
+		timer_base_exit(&to->of_base);
+	goto out;
+}
diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h
new file mode 100644
index 0000000..70b55aee
--- /dev/null
+++ b/drivers/clocksource/timer-of.h
@@ -0,0 +1,67 @@ 
+#ifndef __TIMER_OF_H__
+#define __TIMER_OF_H__
+
+#include <linux/clockchips.h>
+
+#define TIMER_OF_BASE	0x1
+#define TIMER_OF_CLOCK	0x2
+#define TIMER_OF_IRQ	0x4
+
+struct of_timer_irq {
+	int irq;
+	int index;
+	int percpu;
+	const char *name;
+	irq_handler_t handler;
+};
+
+struct of_timer_base {
+	void __iomem *base;
+	const char *name;
+	int index;
+};
+
+struct of_timer_clk {
+	struct clk *clk;
+	const char *name;
+	int index;
+	unsigned long rate;
+	unsigned long period;
+};
+
+struct timer_of {
+	unsigned int flags;
+	struct clock_event_device clkevt;
+	struct of_timer_base of_base;
+	struct of_timer_irq  of_irq;
+	struct of_timer_clk  of_clk;
+};
+
+static inline struct timer_of *to_timer_of(struct clock_event_device *clkevt)
+{
+	return container_of(clkevt, struct timer_of, clkevt);
+}
+
+static inline void __iomem *timer_of_base(struct timer_of *to)
+{
+	return to->of_base.base;
+}
+
+static inline int timer_of_irq(struct timer_of *to)
+{
+	return to->of_irq.irq;
+}
+
+static inline unsigned long timer_of_rate(struct timer_of *to)
+{
+	return to->of_clk.rate;
+}
+
+static inline unsigned long timer_of_period(struct timer_of *to)
+{
+	return to->of_clk.period;
+}
+
+extern int __init timer_of_init(struct device_node *np,
+				struct timer_of *to);
+#endif