Initial import

1 files changed, 160 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
new file mode 100644
index 000000000..3126b920a
--- /dev/null
+++ b/arch/blackfin/kernel/time.c
@@ -0,0 +1,160 @@
+/*
+ * arch/blackfin/kernel/time.c
+ *
+ * This file contains the Blackfin-specific time handling details.
+ * Most of the stuff is located in the machine specific files.
+ *
+ * Copyright 2004-2008 Analog Devices Inc.
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/profile.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+
+#include <asm/blackfin.h>
+#include <asm/time.h>
+#include <asm/gptimers.h>
+
+/* This is an NTP setting */
+#define	TICK_SIZE (tick_nsec / 1000)
+
+static struct irqaction bfin_timer_irq = {
+	.name = "Blackfin Timer Tick",
+};
+
+#if defined(CONFIG_IPIPE)
+void __init setup_system_timer0(void)
+{
+	/* Power down the core timer, just to play safe. */
+	bfin_write_TCNTL(0);
+
+	disable_gptimers(TIMER0bit);
+	set_gptimer_status(0, TIMER_STATUS_TRUN0);
+	while (get_gptimer_status(0) & TIMER_STATUS_TRUN0)
+		udelay(10);
+
+	set_gptimer_config(0, 0x59); /* IRQ enable, periodic, PWM_OUT, SCLKed, OUT PAD disabled */
+	set_gptimer_period(TIMER0_id, get_sclk() / HZ);
+	set_gptimer_pwidth(TIMER0_id, 1);
+	SSYNC();
+	enable_gptimers(TIMER0bit);
+}
+#else
+void __init setup_core_timer(void)
+{
+	u32 tcount;
+
+	/* power up the timer, but don't enable it just yet */
+	bfin_write_TCNTL(TMPWR);
+	CSYNC();
+
+	/* the TSCALE prescaler counter */
+	bfin_write_TSCALE(TIME_SCALE - 1);
+
+	tcount = ((get_cclk() / (HZ * TIME_SCALE)) - 1);
+	bfin_write_TPERIOD(tcount);
+	bfin_write_TCOUNT(tcount);
+
+	/* now enable the timer */
+	CSYNC();
+
+	bfin_write_TCNTL(TAUTORLD | TMREN | TMPWR);
+}
+#endif
+
+static void __init
+time_sched_init(irqreturn_t(*timer_routine) (int, void *))
+{
+#if defined(CONFIG_IPIPE)
+	setup_system_timer0();
+	bfin_timer_irq.handler = timer_routine;
+	setup_irq(IRQ_TIMER0, &bfin_timer_irq);
+#else
+	setup_core_timer();
+	bfin_timer_irq.handler = timer_routine;
+	setup_irq(IRQ_CORETMR, &bfin_timer_irq);
+#endif
+}
+
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+/*
+ * Should return useconds since last timer tick
+ */
+static u32 blackfin_gettimeoffset(void)
+{
+	unsigned long offset;
+	unsigned long clocks_per_jiffy;
+
+#if defined(CONFIG_IPIPE)
+	clocks_per_jiffy = bfin_read_TIMER0_PERIOD();
+	offset = bfin_read_TIMER0_COUNTER() / \
+		(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
+
+	if ((get_gptimer_status(0) & TIMER_STATUS_TIMIL0) && offset < (100000 / HZ / 2))
+		offset += (USEC_PER_SEC / HZ);
+#else
+	clocks_per_jiffy = bfin_read_TPERIOD();
+	offset = (clocks_per_jiffy - bfin_read_TCOUNT()) / \
+		(((clocks_per_jiffy + 1) * HZ) / USEC_PER_SEC);
+
+	/* Check if we just wrapped the counters and maybe missed a tick */
+	if ((bfin_read_ILAT() & (1 << IRQ_CORETMR))
+		&& (offset < (100000 / HZ / 2)))
+		offset += (USEC_PER_SEC / HZ);
+#endif
+	return offset;
+}
+#endif
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "xtime_update()" routine every clocktick
+ */
+#ifdef CONFIG_CORE_TIMER_IRQ_L1
+__attribute__((l1_text))
+#endif
+irqreturn_t timer_interrupt(int irq, void *dummy)
+{
+	xtime_update(1);
+
+#ifdef CONFIG_IPIPE
+	update_root_process_times(get_irq_regs());
+#else
+	update_process_times(user_mode(get_irq_regs()));
+#endif
+	profile_tick(CPU_PROFILING);
+
+	return IRQ_HANDLED;
+}
+
+void read_persistent_clock(struct timespec *ts)
+{
+	time_t secs_since_1970 = (365 * 37 + 9) * 24 * 60 * 60;	/* 1 Jan 2007 */
+	ts->tv_sec = secs_since_1970;
+	ts->tv_nsec = 0;
+}
+
+void __init time_init(void)
+{
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+	arch_gettimeoffset = blackfin_gettimeoffset;
+#endif
+
+#ifdef CONFIG_RTC_DRV_BFIN
+	/* [#2663] hack to filter junk RTC values that would cause
+	 * userspace to have to deal with time values greater than
+	 * 2^31 seconds (which uClibc cannot cope with yet)
+	 */
+	if ((bfin_read_RTC_STAT() & 0xC0000000) == 0xC0000000) {
+		printk(KERN_NOTICE "bfin-rtc: invalid date; resetting\n");
+		bfin_write_RTC_STAT(0);
+	}
+#endif
+
+	time_sched_init(timer_interrupt);
+}