picoxcell: support for Picochip picoxcell devices

[pandora-kernel.git] / arch / arm / mach-picoxcell / time.c

diff --git a/arch/arm/mach-picoxcell/time.c b/arch/arm/mach-picoxcell/time.c
new file mode 100644 (file)
index 0000000..90a554f
--- /dev/null
+++ b/arch/arm/mach-picoxcell/time.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2011 Picochip Ltd., Jamie Iles
+ *
+ * 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.
+ *
+ * All enquiries to support@picochip.com
+ */
+#include <linux/dw_apb_timer.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched.h>
+
+#include <asm/mach/time.h>
+#include <asm/sched_clock.h>
+
+#include "common.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))
+               panic("No clock-freq property for %s", np->name);
+}
+
+static void picoxcell_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 picoxcell_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 DEFINE_CLOCK_DATA(cd);
+static void __iomem *sched_io_base;
+
+unsigned long long notrace sched_clock(void)
+{
+       cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
+
+       return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static void notrace picoxcell_update_sched_clock(void)
+{
+       cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
+
+       update_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static const struct of_device_id picoxcell_rtc_ids[] __initconst = {
+       { .compatible = "picochip,pc3x2-rtc" },
+       { /* Sentinel */ },
+};
+
+static void picoxcell_init_sched_clock(void)
+{
+       struct device_node *sched_timer;
+       u32 rate;
+
+       sched_timer = of_find_matching_node(NULL, picoxcell_rtc_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);
+
+       init_sched_clock(&cd, picoxcell_update_sched_clock, 32, rate);
+}
+
+static const struct of_device_id picoxcell_timer_ids[] __initconst = {
+       { .compatible = "picochip,pc3x2-timer" },
+       {},
+};
+
+static void __init picoxcell_timer_init(void)
+{
+       struct device_node *event_timer, *source_timer;
+
+       event_timer = of_find_matching_node(NULL, picoxcell_timer_ids);
+       if (!event_timer)
+               panic("No timer for clockevent");
+       picoxcell_add_clockevent(event_timer);
+
+       source_timer = of_find_matching_node(event_timer, picoxcell_timer_ids);
+       if (!source_timer)
+               panic("No timer for clocksource");
+       picoxcell_add_clocksource(source_timer);
+
+       of_node_put(source_timer);
+
+       picoxcell_init_sched_clock();
+}
+
+struct sys_timer picoxcell_timer = {
+       .init = picoxcell_timer_init,
+};