clocksource: dw_apb_timer: Add common DTS glue for dw_apb_timer

Make a common device tree glue for clocksource/dw_apb_timer.
Move mach-picoxcell/time.c to be a generic device tree application
of the dw_apb_timer.

Configure mach-picoxcell to use the dw_apb_timer_of device tree
implementation in drivers/clocksource.

Signed-off-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 131 insertions, 0 deletions

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
new file mode 100644
index 000000000000..f7dba5b79b44
--- /dev/null
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2012 Altera Corporation
+ * Copyright (c) 2011 Picochip Ltd., Jamie Iles
+ *
+ * Modified from mach-picoxcell/time.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/dw_apb_timer.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/mach/time.h>
+#include <asm/sched_clock.h>
+
+static void timer_get_base_and_rate(struct device_node *np,
+				    void __iomem **base, u32 *rate)
+{
+	*base = of_iomap(np, 0);
+
+	if (!*base)
+		panic("Unable to map regs for %s", np->name);
+
+	if (of_property_read_u32(np, "clock-freq", rate) &&
+		of_property_read_u32(np, "clock-frequency", rate))
+		panic("No clock-frequency property for %s", np->name);
+}
+
+static void add_clockevent(struct device_node *event_timer)
+{
+	void __iomem *iobase;
+	struct dw_apb_clock_event_device *ced;
+	u32 irq, rate;
+
+	irq = irq_of_parse_and_map(event_timer, 0);
+	if (irq == NO_IRQ)
+		panic("No IRQ for clock event timer");
+
+	timer_get_base_and_rate(event_timer, &iobase, &rate);
+
+	ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
+				     rate);
+	if (!ced)
+		panic("Unable to initialise clockevent device");
+
+	dw_apb_clockevent_register(ced);
+}
+
+static void add_clocksource(struct device_node *source_timer)
+{
+	void __iomem *iobase;
+	struct dw_apb_clocksource *cs;
+	u32 rate;
+
+	timer_get_base_and_rate(source_timer, &iobase, &rate);
+
+	cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
+	if (!cs)
+		panic("Unable to initialise clocksource device");
+
+	dw_apb_clocksource_start(cs);
+	dw_apb_clocksource_register(cs);
+}
+
+static void __iomem *sched_io_base;
+
+static u32 read_sched_clock(void)
+{
+	return __raw_readl(sched_io_base);
+}
+
+static const struct of_device_id sptimer_ids[] __initconst = {
+	{ .compatible = "picochip,pc3x2-rtc" },
+	{ .compatible = "snps,dw-apb-timer-sp" },
+	{ /* Sentinel */ },
+};
+
+static void init_sched_clock(void)
+{
+	struct device_node *sched_timer;
+	u32 rate;
+
+	sched_timer = of_find_matching_node(NULL, sptimer_ids);
+	if (!sched_timer)
+		panic("No RTC for sched clock to use");
+
+	timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
+	of_node_put(sched_timer);
+
+	setup_sched_clock(read_sched_clock, 32, rate);
+}
+
+static const struct of_device_id osctimer_ids[] __initconst = {
+	{ .compatible = "picochip,pc3x2-timer" },
+	{ .compatible = "snps,dw-apb-timer-osc" },
+	{},
+};
+
+static void __init timer_init(void)
+{
+	struct device_node *event_timer, *source_timer;
+
+	event_timer = of_find_matching_node(NULL, osctimer_ids);
+	if (!event_timer)
+		panic("No timer for clockevent");
+	add_clockevent(event_timer);
+
+	source_timer = of_find_matching_node(event_timer, osctimer_ids);
+	if (!source_timer)
+		panic("No timer for clocksource");
+	add_clocksource(source_timer);
+
+	of_node_put(source_timer);
+
+	init_sched_clock();
+}
+
+struct sys_timer dw_apb_timer = {
+	.init = timer_init,
+};