Apply SoC concept to arm926ejs CPUs, i.e. move the SoC specific timer and

[oweals/u-boot.git] / cpu / arm926ejs / versatile / timer.c

diff --git a/cpu/arm926ejs/versatile/timer.c b/cpu/arm926ejs/versatile/timer.c
new file mode 100644 (file)
index 0000000..32872d2
--- /dev/null
+++ b/cpu/arm926ejs/versatile/timer.c
@@ -0,0 +1,175 @@
+/*
+ * (C) Copyright 2003
+ * Texas Instruments <www.ti.com>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002-2004
+ * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+ *
+ * (C) Copyright 2004
+ * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <arm926ejs.h>
+
+#define TIMER_LOAD_VAL 0xffffffff
+
+/* macro to read the 32 bit timer */
+#define READ_TIMER (*(volatile ulong *)(CFG_TIMERBASE+4))
+
+static ulong timestamp;
+static ulong lastdec;
+
+/* nothing really to do with interrupts, just starts up a counter. */
+int timer_init (void)
+{
+       *(volatile ulong *)(CFG_TIMERBASE + 0) = CFG_TIMER_RELOAD;      /* TimerLoad */
+       *(volatile ulong *)(CFG_TIMERBASE + 4) = CFG_TIMER_RELOAD;      /* TimerValue */
+       *(volatile ulong *)(CFG_TIMERBASE + 8) = 0x8C;
+
+       /* init the timestamp and lastdec value */
+       reset_timer_masked();
+
+       return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+
+void reset_timer (void)
+{
+       reset_timer_masked ();
+}
+
+ulong get_timer (ulong base)
+{
+       return get_timer_masked () - base;
+}
+
+void set_timer (ulong t)
+{
+       timestamp = t;
+}
+
+/* delay x useconds AND perserve advance timstamp value */
+void udelay (unsigned long usec)
+{
+       ulong tmo, tmp;
+
+       if(usec >= 1000){               /* if "big" number, spread normalization to seconds */
+               tmo = usec / 1000;      /* start to normalize for usec to ticks per sec */
+               tmo *= CFG_HZ;          /* find number of "ticks" to wait to achieve target */
+               tmo /= 1000;            /* finish normalize. */
+       }else{                          /* else small number, don't kill it prior to HZ multiply */
+               tmo = usec * CFG_HZ;
+               tmo /= (1000*1000);
+       }
+
+       tmp = get_timer (0);            /* get current timestamp */
+       if( (tmo + tmp + 1) < tmp )     /* if setting this fordward will roll time stamp */
+               reset_timer_masked ();  /* reset "advancing" timestamp to 0, set lastdec value */
+       else
+               tmo += tmp;             /* else, set advancing stamp wake up time */
+
+       while (get_timer_masked () < tmo)/* loop till event */
+               /*NOP*/;
+}
+
+void reset_timer_masked (void)
+{
+       /* reset time */
+       lastdec = READ_TIMER;  /* capure current decrementer value time */
+       timestamp = 0;         /* start "advancing" time stamp from 0 */
+}
+
+ulong get_timer_masked (void)
+{
+       ulong now = READ_TIMER;         /* current tick value */
+
+       if (lastdec >= now) {           /* normal mode (non roll) */
+               /* normal mode */
+               timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
+       } else {                        /* we have overflow of the count down timer */
+               /* nts = ts + ld + (TLV - now)
+                * ts=old stamp, ld=time that passed before passing through -1
+                * (TLV-now) amount of time after passing though -1
+                * nts = new "advancing time stamp"...it could also roll and cause problems.
+                */
+               timestamp += lastdec + TIMER_LOAD_VAL - now;
+       }
+       lastdec = now;
+
+       return timestamp;
+}
+
+/* waits specified delay value and resets timestamp */
+void udelay_masked (unsigned long usec)
+{
+       ulong tmo;
+       ulong endtime;
+       signed long diff;
+
+       if (usec >= 1000) {             /* if "big" number, spread normalization to seconds */
+               tmo = usec / 1000;      /* start to normalize for usec to ticks per sec */
+               tmo *= CFG_HZ;          /* find number of "ticks" to wait to achieve target */
+               tmo /= 1000;            /* finish normalize. */
+       } else {                        /* else small number, don't kill it prior to HZ multiply */
+               tmo = usec * CFG_HZ;
+               tmo /= (1000*1000);
+       }
+
+       endtime = get_timer_masked () + tmo;
+
+       do {
+               ulong now = get_timer_masked ();
+               diff = endtime - now;
+       } while (diff >= 0);
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+       return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk (void)
+{
+       ulong tbclk;
+
+       tbclk = CFG_HZ;
+       return tbclk;
+}