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 000000000000..f578176b6d92
--- /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);
+}