ARM: 8366/1: move Dual-Timer SP804 driver to drivers/clocksource

The ARM Dual-Timer SP804 module is peripheral found not only on ARM32
platforms but also on ARM64 platforms.

This patch moves the driver out of arch/arm to driver/clocksource
so that it can be used on ARM64 platforms also.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Olof Johansson <olof@lixom.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 310 insertions, 0 deletions

diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
new file mode 100644
index 000000000000..ca02503f17d1
--- /dev/null
+++ b/drivers/clocksource/timer-sp804.c
@@ -0,0 +1,310 @@
+/*
+ *  linux/drivers/clocksource/timer-sp.c
+ *
+ *  Copyright (C) 1999 - 2003 ARM Limited
+ *  Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * 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, or
+ * (at your option) any later version.
+ *
+ * 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/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <clocksource/timer-sp804.h>
+
+#include "timer-sp.h"
+
+static long __init sp804_get_clock_rate(struct clk *clk)
+{
+	long rate;
+	int err;
+
+	err = clk_prepare(clk);
+	if (err) {
+		pr_err("sp804: clock failed to prepare: %d\n", err);
+		clk_put(clk);
+		return err;
+	}
+
+	err = clk_enable(clk);
+	if (err) {
+		pr_err("sp804: clock failed to enable: %d\n", err);
+		clk_unprepare(clk);
+		clk_put(clk);
+		return err;
+	}
+
+	rate = clk_get_rate(clk);
+	if (rate < 0) {
+		pr_err("sp804: clock failed to get rate: %ld\n", rate);
+		clk_disable(clk);
+		clk_unprepare(clk);
+		clk_put(clk);
+	}
+
+	return rate;
+}
+
+static void __iomem *sched_clock_base;
+
+static u64 notrace sp804_read(void)
+{
+	return ~readl_relaxed(sched_clock_base + TIMER_VALUE);
+}
+
+void __init sp804_timer_disable(void __iomem *base)
+{
+	writel(0, base + TIMER_CTRL);
+}
+
+void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
+						     const char *name,
+						     struct clk *clk,
+						     int use_sched_clock)
+{
+	long rate;
+
+	if (!clk) {
+		clk = clk_get_sys("sp804", name);
+		if (IS_ERR(clk)) {
+			pr_err("sp804: clock not found: %d\n",
+			       (int)PTR_ERR(clk));
+			return;
+		}
+	}
+
+	rate = sp804_get_clock_rate(clk);
+
+	if (rate < 0)
+		return;
+
+	/* setup timer 0 as free-running clocksource */
+	writel(0, base + TIMER_CTRL);
+	writel(0xffffffff, base + TIMER_LOAD);
+	writel(0xffffffff, base + TIMER_VALUE);
+	writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
+		base + TIMER_CTRL);
+
+	clocksource_mmio_init(base + TIMER_VALUE, name,
+		rate, 200, 32, clocksource_mmio_readl_down);
+
+	if (use_sched_clock) {
+		sched_clock_base = base;
+		sched_clock_register(sp804_read, 32, rate);
+	}
+}
+
+
+static void __iomem *clkevt_base;
+static unsigned long clkevt_reload;
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	/* clear the interrupt */
+	writel(1, clkevt_base + TIMER_INTCLR);
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static void sp804_set_mode(enum clock_event_mode mode,
+	struct clock_event_device *evt)
+{
+	unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE;
+
+	writel(ctrl, clkevt_base + TIMER_CTRL);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		writel(clkevt_reload, clkevt_base + TIMER_LOAD);
+		ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* period set, and timer enabled in 'next_event' hook */
+		ctrl |= TIMER_CTRL_ONESHOT;
+		break;
+
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	default:
+		break;
+	}
+
+	writel(ctrl, clkevt_base + TIMER_CTRL);
+}
+
+static int sp804_set_next_event(unsigned long next,
+	struct clock_event_device *evt)
+{
+	unsigned long ctrl = readl(clkevt_base + TIMER_CTRL);
+
+	writel(next, clkevt_base + TIMER_LOAD);
+	writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
+
+	return 0;
+}
+
+static struct clock_event_device sp804_clockevent = {
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+		CLOCK_EVT_FEAT_DYNIRQ,
+	.set_mode	= sp804_set_mode,
+	.set_next_event	= sp804_set_next_event,
+	.rating		= 300,
+};
+
+static struct irqaction sp804_timer_irq = {
+	.name		= "timer",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= sp804_timer_interrupt,
+	.dev_id		= &sp804_clockevent,
+};
+
+void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
+{
+	struct clock_event_device *evt = &sp804_clockevent;
+	long rate;
+
+	if (!clk)
+		clk = clk_get_sys("sp804", name);
+	if (IS_ERR(clk)) {
+		pr_err("sp804: %s clock not found: %d\n", name,
+			(int)PTR_ERR(clk));
+		return;
+	}
+
+	rate = sp804_get_clock_rate(clk);
+	if (rate < 0)
+		return;
+
+	clkevt_base = base;
+	clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
+	evt->name = name;
+	evt->irq = irq;
+	evt->cpumask = cpu_possible_mask;
+
+	writel(0, base + TIMER_CTRL);
+
+	setup_irq(irq, &sp804_timer_irq);
+	clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
+}
+
+static void __init sp804_of_init(struct device_node *np)
+{
+	static bool initialized = false;
+	void __iomem *base;
+	int irq;
+	u32 irq_num = 0;
+	struct clk *clk1, *clk2;
+	const char *name = of_get_property(np, "compatible", NULL);
+
+	base = of_iomap(np, 0);
+	if (WARN_ON(!base))
+		return;
+
+	/* Ensure timers are disabled */
+	writel(0, base + TIMER_CTRL);
+	writel(0, base + TIMER_2_BASE + TIMER_CTRL);
+
+	if (initialized || !of_device_is_available(np))
+		goto err;
+
+	clk1 = of_clk_get(np, 0);
+	if (IS_ERR(clk1))
+		clk1 = NULL;
+
+	/* Get the 2nd clock if the timer has 3 timer clocks */
+	if (of_count_phandle_with_args(np, "clocks", "#clock-cells") == 3) {
+		clk2 = of_clk_get(np, 1);
+		if (IS_ERR(clk2)) {
+			pr_err("sp804: %s clock not found: %d\n", np->name,
+				(int)PTR_ERR(clk2));
+			clk2 = NULL;
+		}
+	} else
+		clk2 = clk1;
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (irq <= 0)
+		goto err;
+
+	of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
+	if (irq_num == 2) {
+		__sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
+		__sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+	} else {
+		__sp804_clockevents_init(base, irq, clk1 , name);
+		__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
+							 name, clk2, 1);
+	}
+	initialized = true;
+
+	return;
+err:
+	iounmap(base);
+}
+CLOCKSOURCE_OF_DECLARE(sp804, "arm,sp804", sp804_of_init);
+
+static void __init integrator_cp_of_init(struct device_node *np)
+{
+	static int init_count = 0;
+	void __iomem *base;
+	int irq;
+	const char *name = of_get_property(np, "compatible", NULL);
+	struct clk *clk;
+
+	base = of_iomap(np, 0);
+	if (WARN_ON(!base))
+		return;
+	clk = of_clk_get(np, 0);
+	if (WARN_ON(IS_ERR(clk)))
+		return;
+
+	/* Ensure timer is disabled */
+	writel(0, base + TIMER_CTRL);
+
+	if (init_count == 2 || !of_device_is_available(np))
+		goto err;
+
+	if (!init_count)
+		__sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
+	else {
+		irq = irq_of_parse_and_map(np, 0);
+		if (irq <= 0)
+			goto err;
+
+		__sp804_clockevents_init(base, irq, clk, name);
+	}
+
+	init_count++;
+	return;
+err:
+	iounmap(base);
+}
+CLOCKSOURCE_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);