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>

3 files changed, 135 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 99c6b203e6cd..e62bc7e9d49b 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -16,6 +16,9 @@ config CLKSRC_MMIO
 config DW_APB_TIMER
         bool
 
+config DW_APB_TIMER_OF
+        bool
+
 config CLKSRC_DBX500_PRCMU
         bool "Clocksource PRCMU Timer"
         depends on UX500_SOC_DB8500
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index dd3e661a124d..2cdaf7d1019f 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -10,4 +10,5 @@ obj-$(CONFIG_EM_TIMER_STI)	+= em_sti.o
 obj-$(CONFIG_CLKBLD_I8253)      += i8253.o
 obj-$(CONFIG_CLKSRC_MMIO)       += mmio.o
 obj-$(CONFIG_DW_APB_TIMER)      += dw_apb_timer.o
+obj-$(CONFIG_DW_APB_TIMER_OF)   += dw_apb_timer_of.o
 obj-$(CONFIG_CLKSRC_DBX500_PRCMU)       += clksrc-dbx500-prcmu.o
\ No newline at end of file
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,
+};