Merge branch 'linux-2.6'

1 files changed, 326 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
new file mode 100644
index 00000000000..f578176b6d9
--- /dev/null
+++ b/arch/blackfin/kernel/time.c
@@ -0,0 +1,326 @@
+/*
+ * File:         arch/blackfin/kernel/time.c
+ * Based on:     none - original work
+ * Author:
+ *
+ * Created:
+ * Description:  This file contains the bfin-specific time handling details.
+ *               Most of the stuff is located in the machine specific files.
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * 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 the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/module.h>
+#include <linux/profile.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/irq.h>
+
+#include <asm/blackfin.h>
+
+/* This is an NTP setting */
+#define	TICK_SIZE (tick_nsec / 1000)
+
+static void time_sched_init(irqreturn_t(*timer_routine)
+			(int, void *));
+static unsigned long gettimeoffset(void);
+static inline void do_leds(void);
+
+#if (defined(CONFIG_BFIN_ALIVE_LED) || defined(CONFIG_BFIN_IDLE_LED))
+void __init init_leds(void)
+{
+	unsigned int tmp = 0;
+
+#if defined(CONFIG_BFIN_ALIVE_LED)
+	/* config pins as output. */
+	tmp = bfin_read_CONFIG_BFIN_ALIVE_LED_DPORT();
+	SSYNC();
+	bfin_write_CONFIG_BFIN_ALIVE_LED_DPORT(tmp | CONFIG_BFIN_ALIVE_LED_PIN);
+	SSYNC();
+
+	/*      First set led be off */
+	tmp = bfin_read_CONFIG_BFIN_ALIVE_LED_PORT();
+	SSYNC();
+	bfin_write_CONFIG_BFIN_ALIVE_LED_PORT(tmp | CONFIG_BFIN_ALIVE_LED_PIN);	/* light off */
+	SSYNC();
+#endif
+
+#if defined(CONFIG_BFIN_IDLE_LED)
+	/* config pins as output. */
+	tmp = bfin_read_CONFIG_BFIN_IDLE_LED_DPORT();
+	SSYNC();
+	bfin_write_CONFIG_BFIN_IDLE_LED_DPORT(tmp | CONFIG_BFIN_IDLE_LED_PIN);
+	SSYNC();
+
+	/*      First set led be off */
+	tmp = bfin_read_CONFIG_BFIN_IDLE_LED_PORT();
+	SSYNC();
+	bfin_write_CONFIG_BFIN_IDLE_LED_PORT(tmp | CONFIG_BFIN_IDLE_LED_PIN);	/* light off */
+	SSYNC();
+#endif
+}
+#else
+void __init init_leds(void)
+{
+}
+#endif
+
+#if defined(CONFIG_BFIN_ALIVE_LED)
+static inline void do_leds(void)
+{
+	static unsigned int count = 50;
+	static int flag = 0;
+	unsigned short tmp = 0;
+
+	if (--count == 0) {
+		count = 50;
+		flag = ~flag;
+	}
+	tmp = bfin_read_CONFIG_BFIN_ALIVE_LED_PORT();
+	SSYNC();
+
+	if (flag)
+		tmp &= ~CONFIG_BFIN_ALIVE_LED_PIN;	/* light on */
+	else
+		tmp |= CONFIG_BFIN_ALIVE_LED_PIN;	/* light off */
+
+	bfin_write_CONFIG_BFIN_ALIVE_LED_PORT(tmp);
+	SSYNC();
+
+}
+#else
+static inline void do_leds(void)
+{
+}
+#endif
+
+static struct irqaction bfin_timer_irq = {
+	.name = "BFIN Timer Tick",
+	.flags = IRQF_DISABLED
+};
+
+/*
+ * The way that the Blackfin core timer works is:
+ *  - CCLK is divided by a programmable 8-bit pre-scaler (TSCALE)
+ *  - Every time TSCALE ticks, a 32bit is counted down (TCOUNT)
+ *
+ * If you take the fastest clock (1ns, or 1GHz to make the math work easier)
+ *    10ms is 10,000,000 clock ticks, which fits easy into a 32-bit counter
+ *    (32 bit counter is 4,294,967,296ns or 4.2 seconds) so, we don't need
+ *    to use TSCALE, and program it to zero (which is pass CCLK through).
+ *    If you feel like using it, try to keep HZ * TIMESCALE to some
+ *    value that divides easy (like power of 2).
+ */
+
+#define TIME_SCALE 1
+
+static void
+time_sched_init(irqreturn_t(*timer_routine) (int, void *))
+{
+	u32 tcount;
+
+	/* power up the timer, but don't enable it just yet */
+	bfin_write_TCNTL(1);
+	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(7);
+
+	bfin_timer_irq.handler = (irq_handler_t)timer_routine;
+	/* call setup_irq instead of request_irq because request_irq calls
+	 * kmalloc which has not been initialized yet
+	 */
+	setup_irq(IRQ_CORETMR, &bfin_timer_irq);
+}
+
+/*
+ * Should return useconds since last timer tick
+ */
+static unsigned long gettimeoffset(void)
+{
+	unsigned long offset;
+	unsigned long clocks_per_jiffy;
+
+	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);
+
+	return offset;
+}
+
+static inline int set_rtc_mmss(unsigned long nowtime)
+{
+	return 0;
+}
+
+/*
+ * timer_interrupt() needs to keep up the real-time clock,
+ * as well as call the "do_timer()" routine every clocktick
+ */
+#ifdef CONFIG_CORE_TIMER_IRQ_L1
+irqreturn_t timer_interrupt(int irq, void *dummy)__attribute__((l1_text));
+#endif
+
+irqreturn_t timer_interrupt(int irq, void *dummy)
+{
+	/* last time the cmos clock got updated */
+	static long last_rtc_update = 0;
+
+	write_seqlock(&xtime_lock);
+
+	do_timer(1);
+	do_leds();
+
+#ifndef CONFIG_SMP
+	update_process_times(user_mode(get_irq_regs()));
+#endif
+	profile_tick(CPU_PROFILING);
+
+	/*
+	 * If we have an externally synchronized Linux clock, then update
+	 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+	 * called as close as possible to 500 ms before the new second starts.
+	 */
+
+	if (ntp_synced() &&
+	    xtime.tv_sec > last_rtc_update + 660 &&
+	    (xtime.tv_nsec / NSEC_PER_USEC) >=
+	    500000 - ((unsigned)TICK_SIZE) / 2
+	    && (xtime.tv_nsec / NSEC_PER_USEC) <=
+	    500000 + ((unsigned)TICK_SIZE) / 2) {
+		if (set_rtc_mmss(xtime.tv_sec) == 0)
+			last_rtc_update = xtime.tv_sec;
+		else
+			/* Do it again in 60s. */
+			last_rtc_update = xtime.tv_sec - 600;
+	}
+	write_sequnlock(&xtime_lock);
+	return IRQ_HANDLED;
+}
+
+void __init time_init(void)
+{
+	time_t secs_since_1970 = (365 * 37 + 9) * 24 * 60 * 60;	/* 1 Jan 2007 */
+
+#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
+
+	/* Initialize xtime. From now on, xtime is updated with timer interrupts */
+	xtime.tv_sec = secs_since_1970;
+	xtime.tv_nsec = 0;
+
+	wall_to_monotonic.tv_sec = -xtime.tv_sec;
+
+	time_sched_init(timer_interrupt);
+}
+
+#ifndef CONFIG_GENERIC_TIME
+void do_gettimeofday(struct timeval *tv)
+{
+	unsigned long flags;
+	unsigned long seq;
+	unsigned long usec, sec;
+
+	do {
+		seq = read_seqbegin_irqsave(&xtime_lock, flags);
+		usec = gettimeoffset();
+		sec = xtime.tv_sec;
+		usec += (xtime.tv_nsec / NSEC_PER_USEC);
+	}
+	while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+
+	while (usec >= USEC_PER_SEC) {
+		usec -= USEC_PER_SEC;
+		sec++;
+	}
+
+	tv->tv_sec = sec;
+	tv->tv_usec = usec;
+}
+EXPORT_SYMBOL(do_gettimeofday);
+
+int do_settimeofday(struct timespec *tv)
+{
+	time_t wtm_sec, sec = tv->tv_sec;
+	long wtm_nsec, nsec = tv->tv_nsec;
+
+	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	write_seqlock_irq(&xtime_lock);
+	/*
+	 * This is revolting. We need to set the xtime.tv_usec
+	 * correctly. However, the value in this location is
+	 * is value at the last tick.
+	 * Discover what correction gettimeofday
+	 * would have done, and then undo it!
+	 */
+	nsec -= (gettimeoffset() * NSEC_PER_USEC);
+
+	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+	set_normalized_timespec(&xtime, sec, nsec);
+	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
+	ntp_clear();
+
+	write_sequnlock_irq(&xtime_lock);
+	clock_was_set();
+
+	return 0;
+}
+EXPORT_SYMBOL(do_settimeofday);
+#endif /* !CONFIG_GENERIC_TIME */
+
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ */
+unsigned long long sched_clock(void)
+{
+	return (unsigned long long)jiffies *(NSEC_PER_SEC / HZ);
+}