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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/frv/kernel/time.c
Initial import
Diffstat (limited to 'arch/frv/kernel/time.c')
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1 files changed, 122 insertions, 0 deletions
diff --git a/arch/frv/kernel/time.c b/arch/frv/kernel/time.c
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+++ b/arch/frv/kernel/time.c
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+/* time.c: FRV arch-specific time handling
+ *
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from arch/m68k/kernel/time.c
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+#include <linux/profile.h>
+#include <linux/irq.h>
+#include <linux/mm.h>
+
+#include <asm/io.h>
+#include <asm/timer-regs.h>
+#include <asm/mb-regs.h>
+#include <asm/mb86943a.h>
+
+#include <linux/timex.h>
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+unsigned long __nongprelbss __clkin_clock_speed_HZ;
+unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
+unsigned long __nongprelbss __res_bus_clock_speed_HZ;
+unsigned long __nongprelbss __sdram_clock_speed_HZ;
+unsigned long __nongprelbss __core_bus_clock_speed_HZ;
+unsigned long __nongprelbss __core_clock_speed_HZ;
+unsigned long __nongprelbss __dsu_clock_speed_HZ;
+unsigned long __nongprelbss __serial_clock_speed_HZ;
+unsigned long __delay_loops_MHz;
+
+static irqreturn_t timer_interrupt(int irq, void *dummy);
+
+static struct irqaction timer_irq = {
+ .handler = timer_interrupt,
+ .name = "timer",
+};
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "xtime_update()" routine every clocktick
+ */
+static irqreturn_t timer_interrupt(int irq, void *dummy)
+{
+ profile_tick(CPU_PROFILING);
+
+ xtime_update(1);
+
+#ifdef CONFIG_HEARTBEAT
+ static unsigned short n;
+ n++;
+ __set_LEDS(n);
+#endif /* CONFIG_HEARTBEAT */
+
+ update_process_times(user_mode(get_irq_regs()));
+
+ return IRQ_HANDLED;
+}
+
+void time_divisor_init(void)
+{
+ unsigned short base, pre, prediv;
+
+ /* set the scheduling timer going */
+ pre = 1;
+ prediv = 4;
+ base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
+
+ __set_TPRV(pre);
+ __set_TxCKSL_DATA(0, prediv);
+ __set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
+ __set_TCSR_DATA(0, base & 0xff);
+ __set_TCSR_DATA(0, base >> 8);
+}
+
+
+void read_persistent_clock(struct timespec *ts)
+{
+ unsigned int year, mon, day, hour, min, sec;
+
+ extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec);
+
+ /* FIX by dqg : Set to zero for platforms that don't have tod */
+ /* without this time is undefined and can overflow time_t, causing */
+ /* very strange errors */
+ year = 1980;
+ mon = day = 1;
+ hour = min = sec = 0;
+ arch_gettod (&year, &mon, &day, &hour, &min, &sec);
+
+ if ((year += 1900) < 1970)
+ year += 100;
+ ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+ ts->tv_nsec = 0;
+}
+
+void time_init(void)
+{
+ /* install scheduling interrupt handler */
+ setup_irq(IRQ_CPU_TIMER0, &timer_irq);
+
+ time_divisor_init();
+}
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+ return jiffies_64 * (1000000000 / HZ);
+}